JP6852020B2 - Lighting device - Google Patents

Description

The present invention relates to a lighting device in which a plurality of light sources are arranged in a line.

Conventionally, as a device for illuminating an area having a predetermined shape, a lighting device in which a plurality of light sources are arranged according to a predetermined shape has been used. For example, in order to illuminate an elongated area, a lighting device in which a plurality of light sources are arranged in a line has been used. By illuminating the desired area, defects and the like in that area can be inspected.

In order to acquire surface information without omission, for example, to detect defects formed on the surface such as scratches without omission, it is necessary to illuminate the surface with light that is brought close to uniform. By arranging a large number of light sources side by side and superimposing the lights emitted from the adjacent light sources, it is possible to illuminate the light having a uniform brightness with less uneven illuminance.

By arranging a large number of light sources side by side, uneven illuminance can be suppressed to some extent. However, the life of the light source may be shortened by the heat generated from the plurality of light sources, and it may be difficult to illuminate the light that is stably and uniformly approached for a long period of time.

Therefore, a device has been proposed in which heat radiation fins are provided in a housing accommodating a light source, and heat generated from the light source is radiated through the heat radiation fins (see, for example, Patent Document 1).

Further, when heat dissipation by the heat dissipation fins is not sufficient, a device has been proposed in which air is supplied to the heat dissipation fins to forcibly cool (forced air cooling) (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2010-20923 Japanese Unexamined Patent Publication No. 2014-179224

The present invention has been made in view of the above points, and an object of the present invention is to provide a lighting device capable of radiating heat generated from a light source and stably illuminating the light.

In order to solve the above problems, the lighting device of the present invention
With multiple light sources arranged along a predetermined direction,
The first lens that collects the light emitted from the light source and
A diffuser lens that diffuses the light emitted from the first lens in the predetermined direction, and a diffuser lens.
A first transmission unit in which the plurality of light sources are provided so as to be heat conductive, and a single second transmission unit which is thermally conductively connected to the first transmission unit and extends in a direction away from the light source. , Prepare,
The second transmission unit has a first surface and a second surface.
A plurality of heat radiating fins are provided on the first surface.
A control circuit unit for controlling the light source is provided on the second surface.

Since the second transmission unit transfers heat to the plurality of heat radiating fins and dissipates heat, stable lighting can be achieved.

According to the present invention, heat generated from a light source or a control circuit unit can be dissipated and stably illuminated.

It is a perspective view which shows the appearance of the lighting apparatus 100 by this Embodiment from the lower side. It is a perspective view which shows the appearance of the lighting apparatus 100 by this embodiment from the upper side. It is a side view which shows the state which removed the cover of the lighting apparatus 100 by this embodiment. It is a perspective view which shows the optical system of the lighting apparatus 100 by this embodiment. It is a perspective view which shows the optical system of the lighting apparatus 100 by this embodiment. It is a perspective view which shows the heat dissipation system of the lighting apparatus 100 by this embodiment. It is a perspective view which shows the outline of the optical path formed by the lighting apparatus 100 by this embodiment. It is a side surface which shows the outline of the optical path formed by the lighting apparatus 100 by this embodiment. FIG. 74 is a front view 74 showing an outline of an optical path formed by the lighting device 100 according to the present embodiment. A diagram (FIG. 10A) showing light traveling along the optical axis direction (Z), a graph (FIG. 10B) showing the intensity distribution at position D1 shown in FIG. 10A, and an intensity distribution at position D2 shown in FIG. 10A are shown. A graph (FIG. 10C), a graph showing the intensity distribution at position D3 shown in FIG. 10A (FIG. 10D), and a graph showing the intensity distribution at position D4 shown in FIG. 10A (FIG. 10E). It is the schematic which shows the structure which arranged the LED 212, the rod lens 220, and the cylindrical lens 240 with different lengths. It is a graph which calculated the illuminance at the position including each position of D1, D2, D3 and D4 shown in FIG. 10A for each case of FIGS. 11A to 11C.

Hereinafter, embodiments will be described with reference to the drawings.

<< First Embodiment >>
According to the first embodiment of the present invention
A plurality of light sources arranged along a predetermined direction (for example, a plurality of LEDs 212 described later) and a plurality of light sources (for example, a plurality of LEDs 212 described later).
A first lens that collects the light emitted from the light source (for example, a rod lens 220 described later) and
A diffusing lens (for example, a diffusing lens 230 described later) that diffuses the light emitted from the first lens in the predetermined direction, and the like.
A second lens (for example, a cylindrical lens 240 described later) that collects light emitted from the diffuser lens is provided.
The radius of curvature of the first lens (for example, the radius of curvature described later) with reference to the center of curvature of the first lens (for example, the center of curvature cc described later) in the direction from the plurality of light sources toward the second lens. An illuminating device is provided in which the second lens is arranged at a position separated by a distance of two times or more (cr or the like).

<Optical system>
The lighting device includes a plurality of light sources, a first lens, a diffusing lens, and a second lens. The optical system of the lighting device is composed of a plurality of light sources, a first lens, a diffusing lens, and a second lens. The optical system of the lighting device has a common optical axis (for example, the optical axis direction Z described later). The optical axis is a virtual light beam that is representative of a luminous flux.

<Direction of light>
In this embodiment, three directions are defined for the direction in which light travels.

<Optical axis direction (for example, Z direction described later)>
One of the three directions is the optical axis direction. As described above, the optical axis is a virtual light beam that is representative of the luminous flux emitted from a plurality of light sources. The optical axis does not have to be a single one-dimensional line, and may be a two-dimensional plane. In the present embodiment, the optical axis direction is virtual when it passes through the central position where the light intensity is the highest among the luminous flux emitted from a plurality of light sources and passing through the first lens, the diffusing lens, and the second lens. It can be in the direction of the light beam that can be made. The optical axis direction is the overall traveling direction of light emitted from a plurality of light sources. In the present embodiment, when it is necessary to distinguish this optical axis from the optical axis of an optical element such as a light source, the optical axis of the optical system (for example, the optical axis T of FIGS. 7 to 9 described later). Etc.).

<Diameter expansion direction>
Further, the light emitted from each of the plurality of light sources gradually spreads in the direction of the optical axis. This light spreads in a substantially conical shape around each of the plurality of light sources (see L1 in FIG. 7 described later). Two directions perpendicular to each other can be defined for the direction in which the light spreads (hereinafter referred to as the diameter-expanding direction).

<Arrangement direction of light sources (first diameter expansion direction (for example, X direction described later))>
The first diameter-expanding direction is a direction along the direction in which a plurality of light sources are arranged, and this direction is referred to as a "light source arrangement direction". The above-mentioned "predetermined direction" means the arrangement direction of the light sources. The arrangement direction of the light sources, which is the first diameter-expanding direction, is a direction perpendicular to the optical axis direction. The length N of the illumination area of the illumination device (see FIG. 7 described later) can be defined by the "arrangement direction of the light sources".

<Width direction of the light source (second diameter expansion direction (for example, Y direction described later))>
Further, the second diameter-expanding direction is a direction perpendicular to the first diameter-expanding direction, and is a direction that defines the width of light emitted from each of the plurality of light sources. This direction is referred to as the "width direction of the light source". The width direction of the light source, which is the second diameter expansion direction, is also a direction perpendicular to the optical axis direction. That is, the width direction of the light source is perpendicular to the two directions of the optical axis direction and the first diameter expansion direction. The width W of the illumination area of the lighting device (see FIG. 7 described later) can be defined by the "width direction of the light source".

<Multiple light sources>
The plurality of light sources are arranged along a predetermined direction. As described above, the "predetermined direction" means the "arrangement direction of the light sources". The arrangement direction of the light sources may be determined according to the shape and size of the object to be illuminated (hereinafter referred to as an illuminated object), and may be a linear direction or a curved direction. Further, the plurality of light sources may be arranged not only in a single row but also in a plurality of rows.

The plurality of light sources are arranged so that the optical axes of the plurality of light sources are in the same direction. Each optical axis of the plurality of light sources is a virtual light ray that is representative of the luminous flux emitted from each of the plurality of light sources. The direction of each optical axis of the plurality of light sources is the same as the direction of the optical axis of the optical system.

<First lens>
The first lens functions as a condensing lens that collects the light emitted from the light source. Preferably, the first lens collects the light emitted from each of the plurality of light sources. The first lens does not necessarily have to be a lens, and may be an optical element capable of condensing light emitted from a light source.

The first lens only needs to be able to collect at least a part of the light emitted from the plurality of light sources. The first lens collects the light emitted from the light source and emits the collected light.

It is preferable that the first lens has a length equivalent to the length in which a plurality of light sources are arranged, and the longitudinal direction of the first lens is arranged along the arrangement direction of the light sources. By arranging the longitudinal direction of the first lens along the arrangement direction of the light sources, the first lens can be arranged so as to be aligned with the arrangement of the plurality of light sources. For example, the first lens is preferably arranged parallel to the arrangement of a plurality of light sources. Light emitted from a plurality of light sources can be incident on the first lens with less leakage.

<Diffusing lens>
The light emitted from the first lens is incident on the diffusing lens. The diffusing lens mainly diffuses the light of the components in the arrangement direction of the light source among the light incident on the diffusing lens. By diffusing the light of the components in the arrangement direction of the light source, the unevenness of the brightness of the components in the arrangement direction of the light source can be suppressed and the brightness can be made uniform. Illuminance, brightness, luminosity, intensity, and the like can be appropriately used as parameters indicating the brightness of light. Regardless of which parameter is used, it is sufficient that the illuminated object can be illuminated with a brightness that is close to uniform.

It is preferable that the diffusing lens also has a length equal to the length of the plurality of light sources arranged side by side and the length of the first lens, and the longitudinal direction of the diffusing lens is arranged along the arrangement direction of the light sources. By arranging the longitudinal direction of the diffuser lens along the arrangement direction of the light sources, the light emitted from a plurality of light sources can be incident on the diffuser lens with less leakage, and the light emitted from the plurality of light sources can be incident. The brightness can be made uniform with respect to the arrangement direction of the light sources. For example, the diffusing lens is preferably arranged in an arrangement of a plurality of light sources or in parallel with the first lens. By arranging the diffuser lenses along the arrangement direction of the light sources, the brightness of the light emitted from multiple light sources can be made uniform and the unevenness of brightness can be reduced, and the light emitted from multiple light sources can be combined into a single light source. It can be treated in the same way as the light emitted from a light source.

The diffusing lens diffuses the light of the components in the arrangement direction of the light source and emits the diffused light. Further, the diffusing lens may also diffuse light of a component in a direction different from the arrangement direction of the light source to transmit the light. By doing so, even if the brightness of the light of the component in the direction different from the arrangement direction of the light source is uneven, the unevenness can be suppressed and the brightness can be made uniform. The degree of diffusion in the arrangement direction of the light sources and the degree of diffusion in a direction different from the arrangement direction of the light sources may be appropriately determined according to the unevenness of brightness that occurs in each direction. For example, the degree of diffusion in the arrangement direction of the light sources can be made larger than the degree of diffusion in a direction different from the arrangement direction of the light sources.

If the unevenness of brightness can be ignored for the light of the component in the direction different from the arrangement direction of the light source, it is diffused only in the arrangement direction of the light source and not in the direction different from the arrangement direction of the light source. Light may be transmitted to the light source.

In this way, the light diffused by the diffusing lens is transmitted through the diffusing lens and emitted.

<Second lens>
Light emitted from the diffusing lens is incident on the second lens. The second lens has a function of collecting the incident light. The second lens collects the light emitted from the diffusing lens and emits the collected light. The second lens does not necessarily have to be a lens, and may be an optical element capable of condensing the light emitted from the diffusing lens.

The second lens also has a length equal to the length of the plurality of light sources arranged side by side, the length of the first lens, and the length of the diffuser lens, and the longitudinal direction of the second lens is arranged along the arrangement direction of the light sources. It is preferable to have it. By arranging the longitudinal direction of the second lens along the arrangement direction of the light source, the light emitted from the diffuser lens can be incident on the second lens with less leakage and collected. For example, the second lens is preferably arranged parallel to the arrangement of a plurality of light sources.

<Condensing process and formed optical path>
The light emitted from the plurality of light sources travels along the optical axis direction of the optical system as a whole. In the present embodiment, the optical axis direction is a direction substantially perpendicular to the arrangement direction of the light sources. The light emitted from the light source gradually spreads and travels around the optical axis of each light source. The light emitted from the plurality of light sources includes light having a component in a direction different from that in the optical axis direction, but travels along the optical axis direction of the optical system as a whole.

The light traveling in the optical axis direction reaches the outer peripheral surface of the first lens and is incident on the first lens. Light that spreads around the optical axis can also enter the first lens.

The light incident on the first lens is refracted according to the refractive index of the first lens. The refracted light travels inside the first lens along the optical axis direction of the optical system as a whole. The light traveling inside the first lens also contains light having a component in a direction different from that in the optical axis direction, but travels along the optical axis direction of the optical system as a whole. The light that has traveled inside the first lens reaches the outer peripheral surface of the first lens.

The light that travels inside the first lens and reaches the outer peripheral surface is refracted according to the refractive index of the first lens and emitted from the first lens. The refraction at the time of incidence and the refraction at the time of exit of the first lens determine the focusing characteristics of the first lens. In this way, the light emitted from the first lens becomes the light focused according to the focusing characteristics of the first lens.

The light emitted from the first lens travels along the optical axis direction as a whole again. The light emitted from the first lens also contains light having a component in a direction different from that in the optical axis direction, but travels along the optical axis direction of the optical system as a whole.

The light traveling in the optical axis direction is incident on the diffusing lens. The diffusing lens diffuses the light of the component in the arrangement direction of the light source more than the light of the component in the direction different from the arrangement direction of the light source. The diffusing lens emits diffused light.

The light emitted from the diffuser lens travels along the optical axis direction as a whole again. The light emitted from the diffusing lens also contains light having a component in a direction different from that in the optical axis direction, but travels along the optical axis direction of the optical system as a whole.

The light traveling in the optical axis direction reaches the incident surface of the second lens and is incident. The light incident on the second lens is refracted according to the refractive index of the second lens. The refracted light travels inside the second lens as a whole along the optical axis direction of the optical system. The light traveling inside the second lens also contains light having a component in a direction different from that in the optical axis direction, but travels along the optical axis direction of the optical system as a whole. The light that has traveled inside the second lens reaches the outer peripheral surface of the second lens.

The light that travels inside the second lens and reaches the outer peripheral surface is refracted according to the refractive index of the second lens and emitted from the second lens. The refraction at the time of incidence and the refraction at the time of exit of the second lens determine the focusing characteristics of the second lens. In this way, the light emitted from the second lens becomes the light focused according to the focusing characteristics of the second lens.

The light emitted from the second lens travels along the optical axis direction as a whole again. The light emitted from the second lens also contains light having a component in a direction different from that in the optical axis direction, but travels along the optical axis direction of the optical system as a whole.

Light emitted from the second lens and traveling along the optical axis direction irradiates the illuminated body to illuminate the illuminated body.

<Center of curvature and radius of curvature of the first lens and the second lens>
The second lens is arranged at a position separated by a distance of at least twice the radius of curvature of the first lens with respect to the center of curvature of the first lens in the direction from the plurality of light sources toward the second lens. That is, with respect to the relative positions of the first lens and the second lens, the first lens and the second lens are arranged at a distance of at least twice the radius of curvature of the first lens with respect to the center of curvature of the first lens. It satisfies the arrangement condition that it is done.

The center of curvature of the first lens is the center of the arc that constitutes the surface of the first lens. The radius of curvature of the first lens is the radius of the arc that constitutes the surface of the first lens. When the curve forming the surface of the first lens is not an arc, the surface of the first lens can be set to have a radius of curvature and a center of curvature that are first-order approximated by an arc.

For example, when the first lens is a rod lens, the radius of curvature of the first lens is the radius of the side surface of the cylinder constituting the rod lens itself, and the center of curvature of the first lens is the side surface of the cylinder constituting the rod lens. It is the center obtained from. Here, the rod lens is a lens having a cylindrical shape, and generally, the side surface of the cylinder is polished with high accuracy and the end surface is a cut surface.

Further, the radius of curvature and the center of curvature of the first lens may be defined as follows. The center obtained from the shape of the entrance surface of the first lens and the shape of the exit surface is the center of curvature, and the radius obtained from the shape of the entrance surface of the first lens and the shape of the exit surface of the first lens is the radius of curvature. Can be done. Here, the incident surface of the first lens is a surface on which light emitted from a plurality of light sources is incident on the first lens. The exit surface of the first lens is a surface on which light is emitted toward the diffusion lens. The center of curvature is preferably located on the optical axis of the optical system. Further, the radius of curvature is preferably a length along the optical axis.

As described above, in the first lens and the second lens, the first lens and the second lens are arranged at a distance of at least twice the radius of curvature of the first lens with respect to the center of curvature of the first lens. The arrangement condition is satisfied. Here, the reference position of the second lens may be the entrance surface, the exit surface, or the center of curvature of the second lens. It is preferably the incident surface of the second lens.

For example, the second lens can be a cylindrical lens or the like. The cylindrical lens has a flat surface having no lens action and a cylindrical surface having a lens action. When the second lens is a cylindrical lens, the incident surface of the second lens can be flat. By using the plane as the reference plane of the second lens, it is possible to easily adjust the optical path to satisfy the above-mentioned arrangement condition.

Further, by using a cylindrical lens as the second lens, the thickness of the second lens in the optical axis direction can be reduced, and by shortening the distance in the optical axis direction, the size and weight can be reduced as a whole.

As described above, in the optical system of the present embodiment, the relative positions of the first lens and the second lens are set to be at least twice the radius of curvature of the first lens with reference to the center of curvature of the first lens. The arrangement condition that the first lens and the second lens are arranged apart from each other (hereinafter, referred to as the first arrangement condition) is satisfied.

In addition to this first arrangement condition, the relative positions of the first lens and the second lens are close to four times or less the radius of curvature of the first lens with respect to the center of curvature of the first lens. It is preferable to satisfy the second arrangement condition that the first lens and the second lens are arranged.

That is, from the first arrangement condition and the second arrangement condition, the relative positions of the first lens and the second lens are at least twice the radius of curvature of the first lens with respect to the center of curvature of the first lens. Moreover, it is preferable that the first lens and the second lens are arranged within a range of 4 times or less. By satisfying this condition, as will be described later, parallel rays can be formed to illuminate the illuminated body.

<Formation of parallel rays>
The light collected and emitted by the first lens may gradually spread and travel as the distance from the first lens increases. By arranging the second lens so as to satisfy the above-mentioned first arrangement condition, the light can be condensed again by the second lens and converted into light traveling substantially in parallel along the optical axis direction. That is, by arranging the first lens and the second lens so as to satisfy the above-mentioned first arrangement condition, it is possible to convert the light into light that is difficult to spread along the optical axis direction.

Further, as described above, the diffusing lens diffuses the light emitted from the first lens in a predetermined direction, that is, in the arrangement direction of the light sources. Therefore, the brightness of the light can be brought close to constant in the arrangement direction of the light sources by diffusion.

By doing so, it is possible to form an illumination region in which the brightness of the region defined by the arrangement direction of the light sources and the width direction of the light sources is close to constant. Further, the optical axis direction is converted into light that travels substantially in parallel along the optical axis direction, so that the size of the illumination region can be made constant along the optical axis direction. That is, by satisfying the first arrangement condition for the first lens and the second lens and diffusing the light in the arrangement direction of the light source by the diffusing lens, the brightness approaches a certain level and is constant along the optical axis direction. It is possible to form an illuminated area having a size.

Further, in the first arrangement condition, the first lens and the second lens are arranged so as to be at least twice the radius of curvature of the first lens as the lower limit of the distance between the first lens and the second lens. It was a thing. However, if the distance between the first lens and the second lens is too long, the second lens may not be able to sufficiently collect light and form parallel rays. Therefore, it is preferable that the first lens and the second lens are arranged so that the upper limit of the distance between the first lens and the second lens is 4 times or less the radius of curvature of the first lens (second lens). Placement conditions). By arranging the first lens and the second lens so as to be included between the upper limit and the lower limit, it is possible to always form the parallel light rays necessary for illuminating the illuminated object.

In this way, it is possible to form an illumination region that approaches a constant brightness and has a constant size along the direction of the optical axis, so that even if the distance from the illuminating device to the illuminated object is different, An area of a certain size can be illuminated with a certain brightness. That is, even if the distance from the lighting device to the illuminated body is changed according to the illuminated body and the usage conditions, it is possible to illuminate a region of a certain size with a constant brightness, and various illuminated bodies and usage conditions. It is possible to provide a lighting device that can handle the above.

It is possible to form light close to parallel light with a simple configuration in which the number of optical elements is small, and it is possible to provide a lighting device that can correspond to various illuminated objects and usage conditions.

<Second embodiment>
A second embodiment of the present invention is the first embodiment of the present invention.
The first optical path length (for example, the length of the optical path L11 described later) until the light emitted from the light source reaches the first lens, and the light emitted from the first lens are transmitted to the second lens. It is shorter than the second optical path length up to that point (for example, the length of the optical path L31 and the optical path L41 described later).

The first optical path length is the length of the optical path until the light emitted from the light source reaches the first lens. The second optical path length is the length of the optical path until the light emitted from the first lens reaches the second lens. The first lens and the second lens are arranged so that the first optical path length is shorter than the second optical path length.

In the first embodiment of the present invention, the arrangement condition is that the first lens and the second lens are arranged at a distance of at least twice the radius of curvature of the first lens with respect to the center of curvature of the first lens. Prescribe. Further, in the second embodiment of the present invention, the optical path length condition that the first optical path length is shorter than the second optical path length is defined.

By making the first optical path length shorter than the second optical path length, the distance between the light source and the first lens can be shortened, and the light emitted from the light source can be efficiently incident on the first lens. Therefore, the light emitted from the light source can be used for illuminating the illuminated body without wasting it. Further, since the distance between the light source and the first lens can be shortened, the lighting device can be miniaturized.

Furthermore, since the second optical path length can be made longer than the first optical path length, the condition for positioning the second lens can be relaxed, and the second lens can be arranged at an optimum position so as to be as close as possible to parallel light. ..

<Third embodiment>
A third embodiment of the present invention is the first embodiment of the present invention.
A heat radiating unit (for example, a heat radiating system 300, which will be described later) having a plurality of heat radiating fins (for example, a heat radiating fin 350, which will be described later) for radiating heat generated by the light source.
A heat transfer unit that is connected to the heat radiating unit and for transferring heat generated by the light source to the heat radiating unit, and is a first transfer unit (for example, a first transfer unit described later) provided so that the light source can conduct heat. A second transmission unit (for example, a second transmission unit 330 described later) that is thermally conductively connected to the first transmission unit and extends in a direction away from the light source. Further includes a heat transfer unit (for example, a heat dissipation frame 310 described later) and the like.
Each of the plurality of radiating fins is formed so as to be separated from each other.
Each of the plurality of heat radiating fins has a fixed end (for example, a fixed end 352 described later) that is thermally conductively connected to the second transmitting portion along the extending direction of the second transmitting portion. It has an open end (for example, an open end 354 described later) formed at a position away from the fixed end.

The lighting device further includes a heat radiating unit and a heat transfer unit.

The heat radiating unit has a plurality of heat radiating fins. The heat generated by the light source is dissipated by the heat dissipation fins. Each of the plurality of heat radiation fins is formed so as to be separated from each other.

The heat transfer unit is connected to the heat radiating unit and transfers the heat generated by the light source to the heat radiating unit. The heat transfer unit has a first transfer unit and a second transfer unit. The heat radiating portion and the first transmitting portion and the second transmitting portion are preferably made of a metal, for example, a material having high thermal conductivity such as aluminum or copper.

A light source is provided in the first transmission unit so as to be heat conductive. The second transmission unit is thermally conductively connected to the first transmission unit. The second transmission portion is formed so as to extend in a direction away from the light source. For example, it is preferable that the second transmission unit is erected at a right angle to the first transmission unit. The heat transferred from the light source to the first transmission unit is transferred to the second transmission unit. The second transmission unit is erected at a right angle to the first transmission unit, and can guide heat in a direction away from the light source. With this configuration, the heat generated from the light source can be guided to be positively separated from the light source.

Further, the fixed ends of the plurality of heat radiating fins are electrically conductively connected along the extending direction of the second transmitting portion, and the heat transferred to the second transmitting portion is transferred to each of the radiating fins. Is transmitted to the fixed end of. The heat transferred to the fixed end of the heat radiating fin is transferred from the fixed end toward the open end, and in the process, it comes into contact with air and can dissipate heat.

In this way, the heat generated by the light source is first transmitted from the first transmission unit to the second transmission unit, then transmitted to the heat radiation fins via the second transmission unit, and then transmitted from the heat radiation fins to the air. It is possible to transfer heat away from the light source so that the light source is not easily affected by the heat. By transferring heat to the second transmission unit instead of immediately transferring it from the first transmission unit to the heat dissipation fins, the heat generated by the light source can be positively released to a position as far as possible from the light source. The light source can be accurately protected from heat.

<Fourth Embodiment>
A fourth embodiment of the present invention is the third embodiment of the present invention.
The heat transfer unit is thermally conductively connected to the first transfer unit, and is separated from each other and faces the first opposed transmission unit (for example, the first opposed transmission unit 340R described later) and the second opposed unit. It has a transmission unit (for example, a second opposed transmission unit 340L described later) and has a transmission unit.
A first sandwiching portion (for example, first sandwiching portions 360RU and 360RB described later) and a second sandwiching portion that sandwich the first lens at a fixed position with respect to the light source and along the first lens. (For example, the second sandwiching portions 360LU and 360LB described later) are provided.
The first holding portion is provided in the first facing transmitting portion so as to be heat conductive, and the second holding portion is provided in the second facing transmitting portion so as to be heat conductive.

The heat transfer unit has a first counter-transmission unit and a second counter-transmission unit. The first opposed transmitting portion and the second opposed transmitting portion are arranged so as to be separated from each other and face each other. The first opposed transmitting portion and the second opposed transmitting portion are thermally conductively connected to the first transmitting portion. The heat transferred to the first opposed transmission unit and the second opposite transmission unit can also be transferred to the second transmission unit via the first transmission unit. The first opposed transmitting portion and the second opposed transmitting portion are also preferably made of a metal, for example, a material having high thermal conductivity such as aluminum or copper.

The first lens is sandwiched along the first lens by the first sandwiching portion and the second sandwiching portion. That is, the first lens is entirely sandwiched by the first sandwiching portion and the second sandwiching portion. The first sandwiching portion and the second sandwiching portion sandwich the first lens at a fixed position with respect to the light source. By sandwiching the first lens between the first sandwiching portion and the second sandwiching portion, the distance between the light source and the first lens can be kept constant, and the optical system can be stably maintained. it can.

The first sandwiching portion is provided on the first opposed transmitting portion so as to be heat conductive. Similarly, the second sandwiching portion is provided in the second opposed transmitting portion so as to be heat conductive. The first sandwiching portion and the second sandwiching portion are also preferably made of a metal, for example, a material having high thermal conductivity such as aluminum or copper.

The first lens may also be affected by heat from the light source. When the first lens is affected by heat, the optical characteristics of the first lens may change due to deformation such as expansion and distortion. As described above, the first lens is entirely sandwiched by the first sandwiching portion and the second sandwiching portion, and the first sandwiching portion is provided on the first opposed transmitting portion so as to be heat conductive. The sandwiching portion of 2 is provided in the second opposed transmitting portion so as to be heat conductive. Therefore, the heat applied to the first lens can be transferred to the first opposed transmitting portion and the second opposed transmitting portion via the first sandwiching portion and the second sandwiching portion.

Since the first lens is entirely sandwiched by the first sandwiching portion and the second sandwiching portion, the first lens transfers heat to the first sandwiching portion and the second sandwiching portion everywhere. be able to. The entire heat of the first lens can be transferred to the first sandwiching portion and the second sandwiching portion.

The heat transferred to the first sandwiching portion and the second sandwiching portion is transferred from the first transmitting portion to the second transmitting portion via the first opposed transmitting portion and the second opposed transmitting portion. As described above, the heat transferred to the second transmission unit is transferred to the heat radiation fins via the second transmission unit, and air is released from the heat radiation fins. In this way, even when heat is applied to the first lens from the light source, heat is dissipated, so that optical characteristics such as light collection characteristics of the first lens can be maintained.

<Fifth Embodiment>
A fifth embodiment of the present invention is the third embodiment of the present invention.
A control circuit unit for controlling the light source (for example, a circuit system 400 described later) is arranged so as to sandwich the heat dissipation unit and the second transmission unit.

The control circuit unit and the heat radiating unit are arranged so as to sandwich the second transmission unit. The control circuit unit is a circuit for controlling the light source. The control circuit section also generates heat when energized. The characteristics of the control circuit section also change due to heat, and the light source may not be sufficiently driven. The control circuit unit is provided directly on the second transmission unit, and the heat generated from the control circuit unit is transferred to the second transmission unit. In this way, the heat generated in the control circuit unit can also be dissipated.

<Sixth Embodiment>
A sixth embodiment of the present invention is the third embodiment of the present invention.
Each of the plurality of heat radiation fins is provided so as to be inclined with respect to both the first transmission portion and the second transmission portion.

Each of the plurality of heat radiating fins is provided so as to be inclined with respect to both the first transmission portion and the second transmission portion.

The open ends of each of the plurality of heat radiation fins can be positioned as far as possible from the light source, and heat can be transferred so as to be as far away from the light source as possible. Further, by inclining each of the plurality of heat radiating fins, air convection can be generated between the adjacent heat radiating fins to improve the heat radiating efficiency.

<7th embodiment>
A seventh embodiment of the present invention is the third embodiment of the present invention.
Each of the plurality of heat radiation fins gradually becomes thinner from the fixed end toward the open end.

By gradually widening the distance between adjacent heat radiating fins toward the open end, it is possible to easily move air from the fixed end to the open end, and the heat radiating efficiency can be improved by convection of air. In addition, the weight can be reduced by gradually reducing the thickness.

<Eighth embodiment>
The eighth embodiment of the present invention is the fourth embodiment of the present invention.
The second lens is provided in the first opposed transmitting portion and the second opposed transmitting portion by a heat insulating member.

The first lens is provided in the first opposed transmitting portion and the second opposed transmitting portion by the first sandwiching portion and the second sandwiching portion capable of conducting heat. That is, the first lens is arranged at a position close to the light source, and is configured to actively release heat. On the other hand, the second lens is provided on the first facing transmission portion and the second facing transmission portion by the heat insulating member. The second lens is arranged at a position far from the light source and is configured so that heat is not positively transferred.

In this way, by selecting whether to dissipate heat or to insulate according to the distance from the light source, it is possible to accurately respond to the heat generated from the light source.

<<< Overview of Lighting Device 100 >>>
The lighting device 100 is a device for illuminating an illuminated body. For example, there is an article for inspecting the surface as an illuminated body. The lighting device 100 is used to illuminate the surface of an article to inspect the presence or absence of defects and the mode of defects.

As will be described later, the illuminating device 100 is formed with a slit-shaped opening 110 (see FIG. 1), and the illuminating device 100 emits elongated light or linear light from the opening 110 to be an illuminated body. It is a lighting device that illuminates the surface of an article, and is a so-called line-type lighting device.

FIG. 1 is a perspective view of the lighting device 100 when viewed from below. FIG. 2 is a perspective view of the lighting device 100 when viewed from above. FIG. 3 is a side view of the lighting device 100 when the side cover is removed.

The lighting device 100 mainly includes an optical system 200, a heat radiating system 300, and a circuit system 400. The optical system 200 generates light for illuminating the object to be illuminated. The heat dissipation system 300 dissipates heat generated from the optical system 200 and the circuit system 400. The circuit system 400 controls and drives the light source of the optical system 200 and the like.

As shown in FIG. 1, the lighting device 100 has an elongated shape. The length of the illuminating device 100 can be appropriately determined according to the length and size of the article to be illuminated. As shown in FIG. 1, the lighting device 100 is formed with an opening 110 at the lower portion. The light R generated by the optical system 200 is emitted from the opening 110. In the examples shown in FIGS. 1 and 2, light R is emitted downward from the opening 110.

As shown in FIGS. 1 to 3, the lighting device 100 is installed so that the opening 110 faces downward, and light R is emitted downward from the opening 110. Further, as shown in FIGS. 1 to 3, the lighting device 100 is installed so that the heat radiation fin 350 is located above the lighting device 100. That is, by installing the lighting device 100 so that the optical system 200, which is the heat generation source, is positioned on the lower side and the heat dissipation system 300 is positioned on the upper side, the opening 356 (FIG. 3) is directed upward, and air convection. Can actively dissipate heat.

<< Optical system 200 >>
The optical system 200 mainly includes a light source 210, a rod lens 220, a diffusion lens 230, and a cylindrical lens 240.

<Light source 210>
The light source 210 is composed of a plurality of LEDs 212. It is preferable to use so-called power LEDs as the plurality of LEDs 212. The power LED is an LED that is driven by a larger current than a general LED. By using the power LED, the brightness can be increased and the illuminance can be increased.

In this embodiment, the LED 212 is mounted on the light source mounting board 214. The light source mounting substrate 214 is a substrate for supplying a current for driving the LED 212. The light source mounting board 214 is a so-called aluminum board, which is a circuit board in which a printed wiring board is bonded to an aluminum base board by an insulating adhesive layer, and LED 212 is mounted on various electronic components.

The aluminum base substrate (not shown) of the light source mounting substrate 214 has a flat shape, and the light source mounting substrate 214 also has a flat shape. The LED 212 is attached to a predetermined position of the light source mounting board 214 so as to emit light in a direction perpendicular to the plane including the light source mounting board 214.

Further, a predetermined number, for example, 26 LEDs 212 are mounted on one light source mounting substrate 214. In the light source mounting substrate 214, 26 LEDs 212 are mounted in a straight line and in a row at equal intervals from each other. As described above, the LED 212 is mounted so as to emit light in a direction perpendicular to the plane including the light source mounting substrate 214, and the light source is mounted so that the optical axes of all 26 LEDs 212 are in the same direction. It is attached to the board 214. The optical axis of the LED 212 is a virtual light beam that is a representative of the luminous flux emitted from the light source.

In the present embodiment, 26 LEDs 212 are mounted on the light source mounting substrate 214 in a straight line and in a row at equal intervals with each other, but the arrangement of the plurality of LEDs 212 is based on the size of the article to be illuminated. It can be appropriately determined according to the shape. For example, it may be arranged along a predetermined curved line or may be arranged in a plurality of rows.

As will be described later, in the present embodiment, the six light source mounting substrates 214 are arranged in a straight line and in a row. Therefore, a total of 156 (= 6 × 26) LEDs 212 are arranged in a straight line and in a row. By arranging the LEDs 212 in a straight line and in a row, the plurality of LEDs 212 can be positioned along the rod lens 220 described later. The number and arrangement of the light source mounting substrates 214 can be appropriately determined according to the size and shape of the article to be illuminated.

The LED 212 is arranged to a predetermined position at the end of the light source mounting board 214, and when a plurality of light source mounting boards 214 are arranged adjacent to each other, the LED 212 adjacent to each other at the boundary of the adjacent light source mounting boards 214 is also present. They are arranged at the same intervals as the adjacent LEDs 212. Therefore, when a plurality of light source mounting substrates 214 are arranged adjacent to each other in a straight line and in a row, all the LEDs 212 can be arranged in a straight line and in a row at equal intervals from each other.

By arranging all the LEDs 212 at equal intervals, the lights emitted from all the LEDs 212 are overlapped with each other, the brightness distribution is aligned and reduced, and the brightness of the lights emitted from the plurality of LEDs 212 is brought close to uniform. be able to. The distance between the adjacent LEDs 212 may be determined according to the required brightness such as illuminance.

The light spread (light distribution) of the plurality of LEDs 212 is preferably wide as long as it can be incident on the rod lens 220 described later. By spreading the light emitted from the LED 212, it is possible to easily overlap each other, reduce the distribution of brightness, and bring the brightness closer to uniform.

<Rod lens 220>
The rod lens 220 is a cylindrical lens and has a cylindrical shape. The rod lens 220 has an elongated shape. The length of the rod lens 220 can be appropriately determined according to the size and shape of the article to be illuminated. The rod lens 220 is made of a synthetic resin such as acrylic. The rod lens 220 may be made of a material that has translucency and can collect light by refraction. In addition to synthetic resin such as acrylic, it may be formed of glass or the like.

As described above, the plurality of LEDs 212 are arranged linearly and in a row. The plurality of LEDs 212 are arranged along the longitudinal direction of the rod lens 220. The light emitted from the plurality of LEDs 212 is incident on the cylindrical side surface 222 of the rod lens 220. In particular, it is preferable that the light emitted from all of the plurality of LEDs 212 is incident on the cylindrical side surface 222 of the rod lens 220. It can be used for illuminating the illuminated body without wasting the light emitted from the plurality of LEDs 212.

The light emitted from the plurality of LEDs 212 is incident on the cylindrical side surface 222 of the rod lens 220. The light incident on the cylindrical side surface 222 is refracted by the cylindrical side surface 222 and enters the inside of the rod lens 220. The light that has entered the inside of the rod lens 220 reaches the cylindrical side surface 222 of the rod lens 220, is refracted by the cylindrical side surface 222, and is emitted from the rod lens 220. The rod lens 220 collects the light emitted from the plurality of LEDs 212 by the refraction at the time of incident and the refraction at the time of exit.

The rod lens 220 collects the light emitted from the plurality of LEDs 212 and adjusts the traveling direction toward the illuminated body.

<Diffusing lens 230>
The diffuser lens 230 has a thin plate shape. The diffuser lens 230 has an elongated shape. The length of the diffuser lens 230 can be appropriately determined according to the size and shape of the article to be illuminated. The diffuser lens 230 is made of a synthetic resin such as polycarbonate or acrylic.

A minute and random lens array (not shown) is formed on the surface of the diffuser lens 230. The diffusion lens 230 uses the diffusion function of the lens array to refract the incident light at a desired diffusion angle (light distribution angle) to perform diffusion shaping. By diffusing light, uneven brightness can be reduced. As a mode of diffusion, for example, a wide-angle circular diffusion that diffuses in a wide range in all directions, a narrow-angle circular diffusion that diffuses in a narrow range in all directions, and a diffusion in a certain direction having an aspect ratio. There is an elliptical diffusion that diffuses more strongly than in other directions.

In this embodiment, a diffuser lens 230 is used to diffuse in the direction in which the plurality of LEDs 212 are arranged. The diffuser lens 230 can reduce the brightness distribution (unevenness) caused by the light emitted separately from each LED 212 in which a plurality of LEDs 212 are arranged so that the brightness can be made uniform.

The incident surface of the diffusing lens 230 is directed toward the rod lens 220, and the exit surface of the diffusing lens 230 is directed at the cylindrical lens 240. The light emitted from the rod lens 220 is incident on the diffusion lens 230. The light incident on the diffusing lens 230 is diffused by a minute lens array formed on the surface of the diffusing lens 230, the brightness is brought close to uniform, and the light is emitted from the exit surface of the diffusing lens 230.

The diffusion mode of the diffusion lens 230 includes the brightness of the plurality of LEDs 212, the distance between the LEDs 212, the degree of light collection of the rod lens 220, the distance between the plurality of LEDs 212 and the rod lens 220, and the rod lens 220 and the diffusion lens 230. It may be decided appropriately depending on the interval between the lens and the lens. By diffusing with the diffusing lens 230, the brightness can be made uniform, and the light emitted from the plurality of LEDs 212 can be treated in the same manner as the light emitted from a single light source.

In the present embodiment, the diffusing lens 230 may sufficiently diffuse and transmit light in the direction in which the plurality of LEDs 212 are arranged, and may transmit the light as it is in the other directions without diffusing. ..

In the present embodiment, the diffusion lens 230 is provided in close contact with the incident surface 242 of the cylindrical lens 240. The light emitted from the diffuser lens 230 immediately enters the incident surface 242 of the cylindrical lens 240. The diffuser lens 230 may be arranged at a distance from the cylindrical lens 240. Another optical element, for example, a lens, a prism, a mirror, or the like can be arranged between the diffuser lens 230 and the cylindrical lens 240 to adjust the optical path.

<Cyrindical lens 240>
The cylindrical lens 240 has a thin plate-like shape as a whole. The cylindrical lens 240 has an elongated shape. The length of the cylindrical lens 240 can be appropriately determined according to the size and shape of the article to be illuminated. The cylindrical lens 240 is formed of a synthetic resin such as polycarbonate or acrylic. Further, it may be formed of glass or the like.

The cylindrical lens 240 has a surface 242 that is formed flat and does not have a lens action, and a surface 244 that has a shape obtained by cutting out a part of a side surface of a cylinder and has a lens action. In the present embodiment, the surface 242 having no lens action is referred to as an incident surface 242, and the surface 244 having a lens action is referred to as an exit surface 244.

The light emitted from the diffusing lens 230 enters the incident surface 242 having no lens action and travels inside the cylindrical lens 240. The light traveling inside the cylindrical lens 240 reaches the exit surface 244 having a lens function. The light that reaches the exit surface 244 is refracted by the exit surface 244. Due to the refraction on the exit surface 244, the cylindrical lens 240 functions to collect the light emitted from the diffusing lens 230.

In the present embodiment, the cylindrical lens 240 collects the light emitted from the diffuser lens 230, converts it into light close to parallel light, and directs the light close to parallel light toward the illuminated body. Exit.

As described above, in the lighting device 100, the light emitted from the plurality of LEDs 212 is brought close to the brightness uniformly by the diffusing lens 230, and the light whose brightness is brought close to the uniform is brought close to the parallel light by the cylindrical lens 240, and the brightness is increased. Produces light that is close to uniform and close to parallel light. Light whose brightness is close to uniform and close to parallel light is emitted from the opening 110 of the illuminating device 100 to illuminate the illuminated object.

As described above, the optical system 200 of the present embodiment has shown the case where it has a light source 210, a rod lens 220, a diffusion lens 230, and a cylindrical lens 240, but other optical elements such as a lens It may have a prism, a mirror, or the like. By providing these optical elements, the optical path can be further adjusted.

<< Optical axis direction (Z direction), light source arrangement direction (X direction), light source width direction (Y direction) >>
<Optical axis direction (Z direction)>
The optical axis is a virtual light beam that is representative of the luminous flux emitted from the plurality of LEDs 212. For example, in the present embodiment, the optical axis direction is the central position where the light intensity is the highest among the light flux emitted from the plurality of LEDs 212 and passing through the rod lens 220, the diffusing lens 230, and the cylindrical lens 240. The direction of the light beam that can be imagined when passing through can be set. The optical axis direction is the overall traveling direction of the light emitted from the plurality of LEDs 212. In the present embodiment, the optical axis direction is the Z direction.

<Diameter expansion direction (X direction and Y direction)>
Further, the light emitted from each of the plurality of LEDs 212 gradually spreads in the optical axis direction according to the light distribution characteristics. This light spreads in a substantially conical shape around the optical axis direction of each of the plurality of LEDs 212 (see L1 in FIG. 7, L11 and L12 in FIG. 8). Two directions perpendicular to each other can be defined for the diameter-expanding direction in which light spreads.

<Arrangement direction of light sources (X direction)>
As shown in FIG. 9, the first diameter-expanding direction is the direction in which the plurality of LEDs 212 are arranged, and is the direction along the plurality of LEDs 212, and this direction is referred to as the "light source arrangement direction". In the present embodiment, 26 LEDs 212 are linearly and in a row attached to the light source mounting substrate 214, and six light source mounting substrates 214 are arranged linearly and in a row. A total of 156 (= 6 × 26) LEDs 212 are arranged in a straight line and in a row. The direction in which the 156 LEDs 212 are arranged in a straight line and in a row is the "light source arrangement direction". The arrangement direction (X direction) of the light sources is perpendicular to the optical axis direction (Z direction).

<Width direction of light source (Y direction)>
The second diameter-expanding direction is a direction perpendicular to the first diameter-expanding direction, and is a direction that defines the width of light emitted from each of the plurality of LEDs 212. This direction is referred to as the "width direction of the light source". The width direction (Y direction) of the light source, which is the second diameter expansion direction, is also a direction perpendicular to the optical axis direction (Z direction). The width of the illumination area of the illuminating device can be defined by the "width direction of the light source".

<< Heat dissipation system 300 >>
The heat dissipation system 300 includes a heat dissipation frame 310. The heat radiating frame 310 has a long shape, and the length in the longitudinal direction is formed to be slightly longer than that of the light source 210, the rod lens 220, the diffusion lens 230, and the cylindrical lens 240. The heat radiating frame 310 is made of a member having high thermal conductivity, for example, a metal such as aluminum. As will be described later, the heat radiating frame 310 may also have a function of holding various parts, can hold various parts at a fixed position, and may be made of a material capable of transmitting heat generated from various parts. ..

Various parts such as an optical system 200 and a circuit system 400 are attached to the heat radiating frame 310. The heat generated from various parts such as the optical system 200 and the circuit system 400 is transferred to the heat radiating fins 350 via the heat radiating frame 310.

The heat dissipation frame 310 also functions as a main part of the housing of the lighting device 100. Various parts such as the optical system 200 and the circuit system 400 are attached and held on the heat radiating frame 310.

The heat radiating frame 310 mainly has a first transmission unit 320, a second transmission unit 330, a first opposed transmission unit 340R, and a second opposed transmission unit 340L, and is integrally formed.

<First transmission unit 320>
The first transmission unit 320 has an elongated plate-like shape. The first transmission unit 320 is a frame that is located at a substantially central portion of the heat dissipation frame 310 and extends in the horizontal direction.

The first transmission portion 320 has a thin plate portion 322a formed to be thin and a thick plate portion 322b formed to be thicker than the thin plate portion 322a. Two cylindrical through holes 324 are formed in the plank portion 322b along the longitudinal direction of the first transmission portion 320. The heat radiating frame 310 can be cooled via the first transmission unit 320 by allowing a refrigerant such as gas or liquid to flow through the two through holes 324 as needed.

The lower surface 326 of the first transmission portion 320 is formed flat. A plurality of light source mounting substrates 214 are attached to the lower surface 326 of the first transmission portion 320 along the longitudinal direction by locking members 216 such as screws and bolts. As described above, the light source mounting substrate 214 has an aluminum substrate (not shown). The light source mounting substrate 214 has an aluminum substrate in close contact with the lower surface 326 of the first transmission portion 320, and the light source mounting substrate 214 is attached to the first transmission portion 320.

The heat generated from the plurality of LEDs 212 is transferred from the aluminum substrate of the light source mounting substrate 214 to the heat radiating frame 310 via the lower surface 326 of the first transmission portion 320. As will be described later, the heat transferred to the heat radiating frame 310 is transferred to the heat radiating fins 350 and radiated. By providing the LED 212 as a heat source on the lower surface 326 of the first transmission unit 320, it is possible to easily transfer the heat generated from the LED 212 in the direction opposite to the optical system 200 (upper side), and the influence of the heat on the optical system 200 can be easily obtained. Can be difficult to give.

By attaching the light source mounting substrate 214 so that the aluminum substrate of the light source mounting substrate 214 is in close contact with the lower surface 326 of the first transmitting portion 320, the plurality of LEDs 212 sandwich the light source mounting substrate 214 and the first transmitting portion 320. It is located on the opposite side of. By doing so, the plurality of LEDs 212 can be arranged so as to emit light downward (toward the rod lens 220).

The plurality of light source mounting substrates 214 are arranged horizontally side by side in close contact with each other on the lower surface 326 of the first transmission unit 320. By arranging the plurality of light source mounting boards 214 in close contact with each other, all of the LEDs 212 mounted on the light source mounting board 214 can be arranged linearly and in a line at equal intervals.

<Second transmission unit 330>
The second transmission unit 330 is erected by being connected to a substantially central portion of the upper surface of the first transmission unit 320. The second transmission unit 330 has an elongated plate-like shape. The second transmission unit 330 is a frame that is vertically erected with respect to the first transmission unit 320 and extends in the vertical direction. The area above the illuminator 100 can be defined by the second transmission unit 330.

The second transmission unit 330 has a first surface 332 and a second surface 334 formed so as to face each other and substantially parallel to each other. The first surface 332 and the second surface 334 extend along the vertical direction.

The gap between the first surface 332 and the upper surface of the first transmission unit 320 is substantially a right angle, and a plurality of heat radiation fins 350 are provided in the region between the first surface 332 and the upper surface of the first transmission unit 320. It is formed. The heat radiation fin 350 has a fixed end 352 and an open end 354. The fixed end 352 is connected to the first surface 332. The heat radiating fin 350 projects from the first surface 332 at an angle different from a right angle with respect to the first surface 332. The open end 354 is located so as to be separated from both the first surface 332 and the upper surface of the first transmission portion 320. The heat radiating fin 350 extends obliquely upward from the fixed end 352.

The heat radiating fin 350 has a substantially rectangular parallelepiped shape having a thin plate shape and a long shape. It is formed along the longitudinal direction of the heat radiating frame 310. The heat radiation fin 350 is formed so that the fixed end 352 is thick and gradually becomes thinner toward the open end 354.

There is air between the adjacent radiating fins 350 to exchange heat. An opening 356 is formed between the open ends 354 of the adjacent heat radiation fins 350. The air warmed by the heat radiated from the heat radiating fin 350 flows upward along the heat radiating fin 350 and flows out from the opening 356. Convection can be generated by the new air flowing between the radiating fins 350 from the vicinity of the fixed end 352 with the outflow from the opening 356.

The heat radiating fins 350 extend diagonally upward, so that the air warmed by the heat radiating can easily flow toward the opening 356, and the heat radiating efficiency can be improved.

The fixed end 352 of the heat radiation fin 350 may be formed not only on the first surface 332 of the second transmission portion 330 but also on the upper surface of the first transmission portion 320. The heat radiation fins 350 formed on the upper surface of the first transmission portion 320 are also formed so as to project obliquely upward from the upper surface of the first transmission portion 320.

By forming the heat radiating fins 350 on the upper surface of the first transmission unit 320, the number of heat radiating fins 350 can be increased, and the heat radiating efficiency can be further improved.

On the surface of the heat radiating fin 350, long ridges (ridges) and long grooves are alternately formed in parallel with each other along the longitudinal direction. By forming the long ridge portion and the long groove portion, the surface area of the heat radiating fin 350 can be increased, and by increasing the area in contact with air, the heat radiating efficiency can be further improved.

A drive circuit 410, which is a circuit system 400, is attached to the second surface 334 of the second transmission unit 330 via a spacer. A commercial power source or the like is connected to the drive circuit 410 and driven. The drive circuit 410 is a circuit that mainly supplies a power supply current, a control signal, and the like to the light source mounting board 214. The drive circuit 410 generates a constant current or the like for driving the LED 212 and supplies it to the light source mounting substrate 214.

As described above, it is preferable to use a power LED as a light source, and the power LED is driven by a large current. Therefore, the power consumption of the drive circuit 410 is large and the amount of heat generated is also large. By attaching the drive circuit 410 to the second transmission unit 330, it becomes easier to transfer the heat generated from the drive circuit 410 to the second transmission unit 330, and by cooling the drive circuit 410, stable operation can be performed. ..

In the above-described example, the case where the plurality of heat radiation fins 350 extend diagonally upward is shown, but the heat radiation fins 350 may extend in the horizontal direction or extend in the vertical direction. Depending on the amount of heat generated from the LED 212 and the size and shape of the first transmission unit 320, the second transmission unit 330, the first opposed transmission unit 340R, and the second opposite transmission unit 340L, the plurality of heat radiation fins 350 All you have to do is determine the orientation.

<First opposed transmission unit 340R and second opposed transmission unit 340L>
The first transmission unit 320 is provided with a first opposite transmission unit 340R and a second opposite transmission unit 340L. As shown in FIG. 3, the first transmission unit 320 has a first end portion 329R and a second end portion 329L in the horizontal direction. In FIG. 3, the first end 329R is the right end and the second end 329L is the left end.

The first opposed transmission unit 340R is a frame that is erected in connection with the first end portion 329R of the lower surface 326 of the first transmission unit 320 and extends in the vertical direction. The second opposed transmission unit 340L is a frame that is erected in connection with the second end portion 329L of the lower surface 326 of the first transmission unit 320 and extends in the vertical direction. The lower region of the illuminating device 100 can be defined by the first opposed transmission unit 340R and the second opposed transmission unit 340L.

A rod lens 220 is arranged between the first opposed transmission unit 340R and the second opposed transmission unit 340L. The rod lens 220 is sandwiched by the first sandwiching portions 360RU and 360RB, and the second sandwiching portions 360LU and 360LB, and is attached to the first opposed transmitting portion 340R and the second opposed transmitting portion 340L.

The first sandwiching portion 360RU sandwiches the rod lens 220 from the upper right side, the first sandwiching portion 360RB sandwiches the rod lens 220 from the lower right side, and the second sandwiching portion 360LU sandwiches the rod lens 220 from the upper left side. The 220 is sandwiched, and the second sandwiching portion 360LB sandwiches the rod lens 220 from the lower left side.

The first sandwiching portions 360RU and 360RB, and the second sandwiching portions 360LU and 360LB are formed of a metal such as aluminum. The first holding portions 360RU and 360RB, and the second holding portions 360LU and 360LB have a long shape and have substantially the same length as the length in the longitudinal direction of the rod lens 220. The first sandwiching portions 360RU and 360RB, and the second sandwiching portions 360LU and 360LB press the rod lens 220 over the entire longitudinal direction of the rod lens 220.

The first sandwiching portions 360RU and 360RB, and the second sandwiching portions 360LU and 360LB all have the same structure, and have a fixed piece 362, a protruding piece 364, and a pressing piece 366. The fixed piece 362 and the protruding piece 364 are connected by a first bent side 368a. The protruding piece 364 and the pressing piece 366 are connected by a second bent side 368b. The fixed piece 362, the protruding piece 364, and the pressing piece 366 have a long shape and are arranged along the longitudinal direction of the rod lens 220. The first bent side 368a and the second bent side 368b also have a long shape and are arranged along the longitudinal direction of the rod lens 220.

The fixing piece 362 is a portion fixed to the first opposed transmission portion 340R and the second opposed transmission portion 340L. The fixing pieces 362 of the first holding portions 360RU and 360RB are fixed to the first opposed transmitting portion 340R by locking members 216 such as bolts and screws. The fixing pieces 362 of the second holding portions 360LU and 360LB are fixed to the second opposed transmitting portion 340L by locking members 216 such as bolts and screws. By fixing the fixing piece 362 to the first opposed transmission portion 340R and the second opposed transmission portion 340L, the entire first sandwiching portions 360RU and 360RB and the second sandwiching portions 360LU and 360LB are fixed. Can be done.

The projecting piece 364 is formed so as to project from the fixed piece 362 via the first bent side 368a. The first bent side 368a is formed by bending and can be elastically deformed around the first bent side 368a. The protruding piece 364 is bent at an angle of approximately 90 degrees with respect to the fixed piece 362. By fixing the fixed piece 362 to the first opposed transmission portion 340R and the second opposed transmission portion 340L, the protruding piece 364 can be elastically deformed from the first opposed transmission portion 340R and the second opposed transmission portion 340L. Protrude.

The pressing piece 366 is formed so as to bend and project from the protruding piece 364 via the second bent side 368b. The second bent side 368b is formed by bending and can be elastically deformed around the second bent side 368b. The pressing piece 366 protrudes elastically from the protruding piece 364 so as to be elastically deformable. The pressing piece 366 is bent at a predetermined obtuse angle with respect to the protruding piece 364. The angle formed by the pressing piece 366 and the protruding piece 364 is appropriately determined by the positions where the first holding portions 360RU and 360RB, the second holding portions 360LU and 360LB are fixed, the diameter of the rod lens 220, and the like. Just do it.

The pressing piece 366 presses the rod lens 220 so as to come into contact with the outer circumference of the rod lens 220 at the contact point P. The pressing pieces 366 of the first sandwiching portions 360RU and 360RB and the second sandwiching portions 360LU and 360LB come into contact with the outer circumference of the rod lens 220 at the contact P to sandwich the rod lens 220. The contact P exists along the longitudinal direction of the rod lens 220, and the pressing piece 366 presses along the longitudinal direction of the rod lens 220.

The rod lens 220 can be elastically deformed at the first bending side 368a and the second bending side 368b, and the rod lens 220 is appropriately pressed by the urging force generated by the elastic deformation, and the rod lens 220 is held in a fixed position by sandwiching the rod lens 220. can do. Since the rod lens 220 is pressed by the urging force generated by the elastic deformation, the rod lens 220 can be held without being damaged.

The rod lens 220 is arranged near the plurality of LEDs 212 so that the light emitted from the plurality of LEDs 212 is incident without leakage. Therefore, the heat generated from the plurality of LEDs 212 may be transferred to the rod lens 220. When the temperature of the rod lens 220 rises, the optical characteristics of the rod lens 220 may change, and it is necessary to release the heat transferred to the rod lens 220.

The first sandwiching portions 360RU and 360RB, and the second sandwiching portions 360LU and 360LB are made of a metal such as aluminum. The heat transferred to the rod lens 220 is transferred to the first opposed transmission unit 340R via the first sandwiching portions 360RU and 360RB, and is transferred to the second opposed transmitting portion 340R via the second sandwiching portions 360LU and 360LB. It is transmitted to 340L. The heat transferred to the first opposed transmission unit 340R and the second opposed transmission unit 340L is transferred to the heat dissipation fins 350 via the heat dissipation frame 310 and can be dissipated.

Further, the pressing pieces 366 of the first holding portions 360RU and 360RB and the second holding portions 360LU and 360LB come into contact with each other along the longitudinal direction of the rod lens 220. Therefore, heat can be transferred to the first opposed transmission unit 340R and the second opposed transmission unit 340L from any position in the longitudinal direction of the rod lens 220, and the entire rod lens 220 can be dissipated. The overall optical characteristics of the rod lens 220 can be maintained by the overall heat dissipation.

The first sandwiching portions 360RU and 360RB, and the second sandwiching portions 360LU and 360LB may be made of not only aluminum but also those that are elastically deformable and have high thermal conductivity.

<Step 380 and taper 382>
A step portion 380 is formed on the outside of the first opposed transmission portion 340R and the second opposed transmission portion 340L. A cover (not shown) of the housing is locked to the step portion 380. By forming the stepped portion 380, the cover of the housing can be attached to the first opposed transmitting portion 340R and the second opposed transmitting portion 340L at a fixed position, and various optical elements constituting the optical system 200 can be attached. It can be protected accurately. Further, when the cover of the housing is attached, the outer surface can be flattened, the positioning of the lighting device 100 and the like can be facilitated, and the handling can be simplified.

Further, a tapered portion 382 is formed on the outside of the first opposed transmitting portion 340R and the second opposed transmitting portion 340L. By forming the tapered portion 382 according to the formation of the stepped portion 380, the thickness of the first opposed transmitting portion 340R and the second opposed transmitting portion 340L is maintained, and the first opposed transmitting portion 340R and the second opposed transmitting portion 340R are maintained. The strength of the part 340L can be secured. Further, by maintaining the thickness, the heat capacity can be adjusted and the heat dissipation state can be stabilized.

<Groove 384>
A groove 384 is formed on the upper side of the second end 329L of the first transmission 320. The groove portion 384 is formed over the entire length direction of the first transmission portion 320, and the cover sheet metal (not shown) can be stably locked and attached to the groove portion 384.

<Groove 386R and Groove 386L>
A groove portion 386R is formed at the first end portion 329R of the first transmission portion 320, and a groove portion 386L is formed at the second end portion 329L of the first transmission portion 320. Both the groove portion 386R and the groove portion 386L are formed over the entire length direction of the first transmission portion 320. A slide nut for attaching the lighting device 100 is inserted into the groove portion 386R and the groove portion 386L. The illuminating device 100 can be supported by slide nuts at a plurality of positions of the groove portion 386R and the groove portion 386L, and the illuminating device 100 can be held at a fixed position. By holding the illuminating device 100 at a fixed position, it is less likely to be affected by external vibrations and the like, and the light R emitted from the opening 110 can be stably illuminated on the illuminated body.

<Holding of cylindrical lens 240>
Two holding members 370 are attached to the tip portions of the first opposed transmission portion 340R and the second opposed transmission portion 340L. The two holding members 370 hold the cylindrical lens 240 in the first opposed transmission unit 340R and the second opposed transmission unit 340L.

The two holding members 370 are made of a heat-insulating resin. The cylindrical lens 240 is attached to the first opposed transmission unit 340R and the second opposed transmission unit 340L by the resin-based holding member 370.

The temperature of the first opposed transmission unit 340R and the second opposed transmission unit 340L may increase due to the heat generated from the plurality of LEDs 212 or the heat transferred via the rod lens 220. As described above, the cylindrical lens 240 is formed of a synthetic resin such as polycarbonate or acrylic. Further, the diffusion lens 230 is provided in close contact with the cylindrical lens 240. The diffuser lens 230 is made of a synthetic resin such as polycarbonate or acrylic.

Therefore, when heat is transferred from the first opposed transmission unit 340R and the second opposed transmission unit 340L to the diffuser lens 230 and the cylindrical lens 240, the diffuser lens 230 and the cylindrical lens 240 are damaged by the heat or the optical characteristics are changed. May change.

By forming the two holding members 370 with a resin having heat insulating properties, the heat insulating properties of the resin make it difficult for heat to be transferred to the diffuser lens 230 and the cylindrical lens 240, and the diffuser lens 230 and the cylindrical lens 240 are damaged or have optical characteristics. Can be prevented from changing.

As described above, the rod lens 220 is sandwiched by the first sandwiching portions 360RU and 360RB, and the second sandwiching portions 360LU and 360LB, and is attached to the first opposed transmitting portion 340R and the second opposed transmitting portion 340L. .. The first sandwiching portions 360RU and 360RB, and the second sandwiching portions 360LU and 360LB are formed of a metal such as aluminum having high thermal conductivity. The heat transferred from the LED 212 to the rod lens 220 is transferred to the first opposed transmitting portion 340R and the second opposed transmitting portion 340L via the first sandwiching portions 360RU and 360RB and the second sandwiching portions 360LU and 360LB. It can convey and dissipate heat.

In this way, not only the heat transferred to the rod lens 220 may be dissipated, but also the rod lens 220 may be supported by the heat insulating member as in the cylindrical lens 240. Whether the support portion with the rod lens 220 is configured to dissipate heat or to insulate depends on the heat and temperature distribution depending on the heat generated from the LED 212 and the distance between the LED 212 and the rod lens 220. It should be decided based on.

<< Circuit system 400 >>
The circuit system 400 includes a drive circuit 410. The drive circuit 410 is a circuit that mainly supplies a power supply current, a control signal, and the like to the light source mounting board 214. The drive circuit 410 generates a constant current or the like for driving the LED 212 and supplies it to the light source mounting substrate 214. A commercial power source or the like is connected to the drive circuit 410 and driven. The drive circuit 410 generates a large current for supplying the LED 212 and generates various drive currents. Therefore, the power consumption of the drive circuit 410 is large and the amount of heat generated is also large. It is necessary to appropriately dissipate the heat generated from the drive circuit 410.

A LAN connector (not shown) to which a LAN cable can be connected is also provided. A control device is connected via a LAN cable, and the control device can perform detailed control such as dimming, lighting, and extinguishing of the LED 212.

Further, a BNC connector (not shown) to which a BNC cable can be connected is also provided. By inputting a pulse signal via the BNC connector, high-speed blinking control can be performed according to the frequency of the pulse signal.

<<< Optical path in optical system 200 >>>
As described above, the optical system 200 mainly includes a light source 210, a rod lens 220, a diffusion lens 230, and a cylindrical lens 240. The optical paths generated by these optical elements will be described below.

<<< Formation of optical path >>>
As shown in FIGS. 7 to 9, the light L1 emitted from the plurality of LEDs 212 travels along the optical axis direction (Z direction) of the optical system as a whole. The light L1 emitted from the light source travels while gradually spreading around the optical axis T of the optical system according to the light distribution characteristics. The light L1 emitted from the plurality of LEDs 212 includes light (L12) having a component in a direction different from that in the optical axis direction (L11), but travels along the optical axis direction of the optical system as a whole. ..

The light L11 traveling in the optical axis direction (see FIGS. 8 and 9) reaches the cylindrical side surface 222 of the rod lens 220 and is incident on the rod lens 220. Light L12 (see FIGS. 8 and 9) spread around the optical axis T can also be incident on the rod lens 220.

Of the light L1 incident on the rod lens 220, the light obliquely incident on the cylindrical side surface 222 of the rod lens 220 is refracted according to the refractive index of the rod lens 220. The light L2 incident on the rod lens 220 travels inside the rod lens 220 as a whole along the optical axis direction (Z direction) of the optical system. The light L2 traveling inside the rod lens 220 also contains light (L21) having a component in the optical axis direction as well as light (L22) having a component in a direction different from that in the optical axis direction. As it advances along the optical axis direction of the optical system. The light L2 that has traveled inside the rod lens 220 reaches the cylindrical side surface 222 of the rod lens 220.

The light that travels inside the rod lens 220 and reaches the cylindrical side surface 222 is refracted according to the refractive index of the rod lens 220. The refracted light is emitted from the rod lens 220. The refraction at the time of incident and the refraction at the time of exit of the rod lens 220 determine the focusing characteristics of the rod lens 220. In this way, the light L3 emitted from the rod lens 220 becomes the light focused according to the focusing characteristics of the rod lens 220.

The light L3 emitted from the rod lens 220 travels along the optical axis direction as a whole again. The light L3 emitted from the rod lens 220 also contains light (L32) having a component in a direction different from the component in the optical axis direction (L31), but travels along the optical axis direction of the optical system as a whole.

The light L3 emitted from the rod lens 220 is incident on the diffusion lens 230. As described above, a minute lens array is formed on the surface of the diffuser lens 230. The light L4 incident on the diffuser lens 230 is diffused by the lens array. The diffusing lens 230 diffuses and emits light (L43) as a component in the arrangement direction (X direction) of the light source (FIG. 9). Further, light of another component (L41, L42, etc.) different from the component in the arrangement direction of the light source is emitted by not diffusing or weakly diffusing (FIG. 8).

As described above, in the present embodiment, the diffuser lens 230 is provided in close contact with the incident surface 242 of the cylindrical lens 240. The light emitted from the diffuser lens 230 immediately enters the incident surface 242 of the cylindrical lens 240. The light L5 incident on the cylindrical lens 240 is refracted according to the refractive index of the cylindrical lens 240. The refracted light L5 travels inside the cylindrical lens 240 as a whole along the optical axis direction of the optical system. The light traveling inside the cylindrical lens 240 also contains light (L52) having a component in a direction different from the component in the optical axis direction (L51), but as a whole, it is in the optical axis direction (Z direction) of the optical system. Proceed along. The light that has traveled inside the cylindrical lens 240 reaches the exit surface 244 of the cylindrical lens 240.

The light L5 that has traveled inside the cylindrical lens 240 and reached the exit surface 244 is refracted according to the refractive index of the cylindrical lens 240. The refracted light is emitted from the exit surface 244 of the cylindrical lens 240. The refraction at the time of incident and the refraction at the time of exit of the cylindrical lens 240 determine the focusing characteristics of the cylindrical lens 240. As described above, the light R emitted from the cylindrical lens 240 becomes the focused light according to the focusing characteristics of the cylindrical lens 240.

The light R emitted from the cylindrical lens 240 travels along the optical axis direction (Z direction) as a whole. The light R emitted from the cylindrical lens 240 irradiates the illuminated body to illuminate the illuminated body (see FIGS. 1 and 2).

<Arrangement conditions for the rod lens 220 and the cylindrical lens 240 (first arrangement condition)>
In the direction from the plurality of LEDs 212 toward the cylindrical lens 240 (for example, the optical axis direction Z), at a position separated by a distance of at least twice the radius of curvature cr of the rod lens 220 with reference to the center of curvature cc of the rod lens 220. A cylindrical lens 240 is arranged. That is, with respect to the relative positions of the rod lens 220 and the cylindrical lens 240, the rod lens 220 and the cylindrical lens 240 are separated from each other by at least twice the radius of curvature cr of the rod lens 220 with reference to the center of curvature cc of the rod lens 220. Satisfies the first arrangement condition that is arranged.

The center of curvature cc of the rod lens 220 is the center of the side surface of the cylinder that constitutes the side surface of the rod lens 220. The radius of curvature cr of the rod lens 220 is the radius of the side surface of the cylinder forming the side surface of the rod lens 220.

Further, the reference position of the cylindrical lens 240 may be the incident surface 242 of the cylindrical lens 240, the exit surface 244, or the center of curvature cc. It is preferably the incident surface 242 of the cylindrical lens 240.

As described above, in the rod lens 220 and the cylindrical lens 240, the rod lens 220 and the cylindrical lens 240 are arranged at a distance of at least twice the radius of curvature cr of the rod lens 220 with respect to the center of curvature cc of the rod lens 220. The first arrangement condition of being done is satisfied. Specifically, in the example shown in FIG. 8, the first arrangement condition is that the distance between the rod lens 220 and the cylindrical lens 240 (radius of curvature cr + length of optical path L31 + length of optical path L41) is determined. The rod lens 220 and the cylindrical lens 240 are arranged so as to be at least twice the radius of curvature cr of the rod lens 220.

<Formation of parallel rays>
The light collected and emitted by the rod lens 220 may gradually spread and travel as the distance from the rod lens 220 increases. By arranging the cylindrical lens 240 so as to satisfy the first arrangement condition described above, the light can be condensed again by the cylindrical lens 240 and converted into light traveling substantially in parallel along the optical axis direction (Z direction). it can. In other words, the first arrangement condition that the cylindrical lens 240 is arranged at a position separated by a distance of at least twice the radius of curvature cr of the rod lens 220 with respect to the center of curvature cc of the rod lens 220 in the optical axis direction. By satisfying the above conditions, it is possible to form light that is difficult to spread along the optical axis direction (Z direction), that is, light that is close to parallel light.

Furthermore, as described above, the diffuser lens diffuses the light emitted from the rod lens 220 in a predetermined direction, that is, in the arrangement direction (X direction) of the light sources. Therefore, the brightness of the light can be brought close to constant in the arrangement direction (X direction) of the light sources by diffusion.

By doing so, the brightness of the region defined by the arrangement direction (X direction) of the light sources and the width direction (Y direction) of the light sources is brought close to a constant brightness (A1, A2, A3 in FIG. 7). Can be formed. Further, since the light in the optical axis direction (Z direction) is converted into light traveling substantially in parallel along the optical axis direction, the size of the illumination region (A1, A2, A3 in FIG. 7) is changed in the optical axis direction (Z). Can be constant along the direction). That is, the rod lens 220 and the cylindrical lens 240 satisfy the first arrangement condition, and the diffuser lens diffuses the light in the arrangement direction of the light sources to achieve a constant brightness along the optical axis direction (Z direction). Illumination regions (A1, A2, A3 in FIG. 7) that are close to each other and have a certain size can be formed.

The first arrangement condition described above is that the lower limit of the distance between the rod lens 220 and the cylindrical lens 240 is that the distance between the rod lens 220 and the cylindrical lens 240 is at least twice the radius of curvature cr of the rod lens 220. The rod lens 220 and the cylindrical lens 240 were arranged so as to be. However, if the distance between the rod lens 220 and the cylindrical lens 240 is too long, the cylindrical lens 240 may not be able to sufficiently collect light and form parallel rays. Therefore, it is preferable that the rod lens 220 and the cylindrical lens 240 are arranged so that the upper limit of the distance between the rod lens 220 and the cylindrical lens 240 is 4 times or less the radius of curvature of the rod lens 220 (second). Placement conditions). By arranging the rod lens 220 and the cylindrical lens 240 so as to be included between the upper limit and the lower limit, it is possible to always form parallel rays necessary for illuminating the illuminated object.

In this way, with respect to the relative positions of the rod lens 220 and the cylindrical lens 240, the rod lens is within a range of 2 times or more and 4 times or less of the radius of curvature of the rod lens 220 with reference to the center of curvature of the rod lens 220. It is preferable to arrange the 220 and the cylindrical lens 240.

In this way, it is possible to form an illumination region (A1, A2, A3 in FIG. 7) that approaches a constant brightness and has a constant size along the optical axis direction (Z direction), and thus is illuminated by the illumination device. Even when the distances to the body (D1, D2, D3 in FIG. 7) are different, it is possible to illuminate a region of a certain size with a constant brightness. That is, even when the distance from the illuminating device to the illuminated object (D1, D2, D3 in FIG. 7) is changed according to the illuminated object and the usage conditions, a region of a certain size is illuminated with a constant brightness. It is possible to provide a lighting device that can correspond to various illuminated objects and usage conditions.

As described above, it is possible to form light close to parallel light with a simple configuration in which the number of optical elements is small, and it is possible to provide a lighting device capable of corresponding to various illuminated objects and usage conditions.

FIG. 10 is a diagram showing an optical path when the above-mentioned arrangement condition is satisfied and an intensity distribution at four locations D1, D2, D3, and D4 along the optical axis direction.

As shown in FIG. 10A, some light spreads along the optical axis direction (Z), but most of the light travels in the optical axis direction without spreading. FIG. 10B is a graph showing the intensity distribution at the position D1 shown in FIG. 10A. FIG. 10C is a graph showing the intensity distribution at position D2 shown in FIG. 10A. FIG. 10D is a graph showing the intensity distribution at the position D3 shown in FIG. 10A. FIG. 10E is a graph showing the intensity distribution at the position D4 shown in FIG. 10A.

As shown in FIGS. 10B to 10E, the intensity in the range of −10 to +10 in the Y direction is larger than I1 at the distances D1 to D4, and the brightness for illuminating the non-illuminated body can be secured.

<< Characteristics of illuminance according to the distance from the cylindrical lens 240 to the illuminated object >>
<Arrangement configuration>
FIG. 11 is a diagram showing a configuration in which the LED 212, the rod lens 220, and the cylindrical lens 240 are arranged with different lengths. For the sake of simplicity, the diffuser lens 230 is omitted in FIG.

Also in FIG. 11, the length from the LED 212 to the cylindrical side surface 222 of the rod lens 220 is defined as the length of L11, and the length from the cylindrical side surface 222 of the rod lens 220 to the incident surface 242 of the cylindrical lens 240 is defined as the length of L31 + L41 (FIG. 11). 8). Further, the radius of curvature of the rod lens 220 is cr, and the center of curvature of the rod lens 220 is cc.

In FIG. 11A, the relationship of L11 <L31 + L41 is satisfied, and the length (= radius of curvature cr + L31 + L41) from the center of curvature cc of the rod lens 220 to the incident surface 242 of the cylindrical lens 240 is twice the radius of curvature cr of the rod lens 220. It is a figure which shows the case which becomes the above length.

FIG. 11B satisfies the relationship of L11 <L31 + L41, and the length (= radius of curvature cr + L31 + L41) from the center of curvature cc of the rod lens 220 to the incident surface 242 of the cylindrical lens 240 is twice or less the radius of curvature cr of the rod lens 220. It is a figure which shows the case which becomes the length of.

FIG. 11C is a diagram showing a case where the relationship of L11 = L31 + L41 is satisfied.

FIG. 12 is a graph for calculating the illuminance at a position including each position of D1, D2, D3 and D4 shown in FIG. 10A for each of the cases of FIGS. 11A to 11C. The vertical axis indicates the illuminance, and the horizontal axis indicates the distance from the exit surface 244 of the cylindrical lens 240 to the irradiated body.

The straight line (a) in FIG. 12 shows the fluctuation of the illuminance in the case of FIG. 11A. The straight line (b) in FIG. 12 shows the fluctuation of the illuminance in the case of FIG. 11B. The straight line (c) in FIG. 12 shows the fluctuation of the illuminance in the case of FIG. 11C.

As shown in FIG. 12, in each case, the illuminance at the position D1 is the highest, and the illuminance gradually decreases as the distance from the position D2, the position D3 and the position D4 and the cylindrical lens 240 increases.

Here, assuming that the fluctuation rate of the illuminance is (1-D4 / D1 × 100), the fluctuation rate of the illuminance in the case of FIG. 11A is about 40% from the slope of the straight line (a), and the fluctuation of the illuminance in the case of FIG. 11B. The rate is about 47% from the slope of the straight line (b), and the fluctuation rate of the illuminance in the case of FIG. 11C is about 66% from the slope of the straight line (c). As described above, the fluctuation of the illuminance is the smallest in the case of FIG. 11A.

Further, it is considered that the illuminance can be further increased while suppressing the fluctuation of the illuminance by increasing the light emitting area of the LED 212. For reference, the light emitting area of the LED 212 is increased by about 1.5 times with the same arrangement in FIG. 11A. This case is shown as a straight line (a1) in FIG.

Comparing the straight line (a) and the straight line (a1), the illuminance of the straight line (a) is higher at the position D1 than that of the straight line (a1). Further, it is the straight line (a) that the fluctuation of the illuminance is small between the distances D1 to D4. As described above, even if the light emitting area of the LED 212 is increased, the fluctuation of the illuminance cannot be suppressed to be smaller than that in the case where the light emitting area of the LED 212 is small, and the illuminance cannot be increased. The volatility of the illuminance of the straight line (a1) was about 46%.

By arranging the arrangement shown in FIG. 11A in this way, fluctuations in illuminance can be suppressed to a small extent. In other words, the illuminated body can be illuminated by making the brightness of the light emitted from the cylindrical lens 240 close to parallel light while making it uniform. For example, even when the position of the illuminated body fluctuates due to vibration or the like, it is possible to illuminate a certain area with a certain brightness.

100 Lighting device 200 Optical system 300 Heat dissipation system 400 Circuit system

Claims (4)

With multiple light sources arranged along a predetermined direction,
A long condensing lens that condenses the light emitted from the light source,
A diffuser lens that diffuses the light emitted from the condenser lens in the predetermined direction,
A first transfer unit provided with the plurality of light sources and capable of conducting heat generated from the light source, and a second transfer unit that is thermally conductively connected to the first transfer unit and extends in a direction away from the light source. Transmission part and
A first opposed transmitting portion and a second opposed transmitting portion which are connected to the first transmitting portion and are separated from each other and are capable of conducting heat.
It is attached to the first opposed transmitting portion along the entire longitudinal direction of the condensing lens, and is elastically deformable and heat conductive and long between the condensing lens and the first opposed transmitting portion. With the first long pinch,
It is attached to the second opposed transmitting portion along the entire longitudinal direction of the condensing lens, and is elastically deformable and heat conductive and long between the condensing lens and the second opposed transmitting portion. Equipped with a long second holding part,
The condensing lens is pressed over the entire longitudinal direction by the urging force generated by the elastic deformation of the first holding portion and the urging force generated by the elastic deformation of the second holding portion, and can conduct heat. A lighting device sandwiched between the two and arranged between the first opposed transmitting portion and the second opposed transmitting portion. The second transmission unit has a first surface and a second surface.
A plurality of heat radiating fins are provided on the first surface.
A control circuit unit for controlling the light source is provided on the second surface.
The heat generated from the light source is transferred to the plurality of heat radiating fins via the first transmission unit and the second transmission unit.
The lighting device according to claim 1, wherein the heat generated from the control circuit unit is transferred to the plurality of heat radiation fins via the second transmission unit. The lighting device according to claim 2 , wherein each of the plurality of heat radiation fins is provided so as to be inclined with respect to both the first transmission unit and the second transmission unit. Each of the plurality of heat radiating fins is formed at a fixed end that is thermally conductively connected to the second transmitting portion along the extending direction of the second transmitting portion and at a position away from the fixed end. The lighting device according to claim 2 , which has an open end and gradually narrows from the fixed end toward the open end.

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