JP6125786B2 - Optical component, light guide member usable for optical component, and light irradiation device - Google Patents

Description

  The present invention relates to an optical component for synthesizing light from a plurality of light emitting elements, a light guide member usable for the optical component, and a light irradiation apparatus using the optical component.

  In recent years, light-emitting elements such as light-emitting diodes (hereinafter abbreviated as LEDs), electroluminescence (hereinafter abbreviated as EL), and plasma light emitters have attracted attention. These have the advantages of light environmental impact, good energy efficiency, and long life. However, compared with a discharge lamp or a filament lamp, there is a problem that a single unit emits less light and is vulnerable to a high temperature environment. For example, in an LED, even if an attempt is made to increase the amount of light emission by increasing the size of a semiconductor and passing a large amount of current, the amount of heat generation increases and there is a limit. In addition, there is a limit in the method in which a plurality of LEDs are concentrated in a narrow area and lit to increase the total heat generation amount. In a high temperature environment, the amount of emitted light with respect to the power input to the light emitting element is reduced, and the life of the light emitting element is shortened.

  In order to solve this problem, a condensing device is disclosed that combines light from a plurality of light emitting diodes using the same number of rod-shaped light guide members (Patent Document 1). This rod-shaped light guide member is a rod having the same area of the cylindrical entrance surface and the exit surface (that is, cylindrical) and has a structure in which the vicinity of the exit surface is bundled together. For this reason, the area of the emission surface increases in proportion to the increase in the number of light emitting diodes, and the area of the gap between the rods is useless. Patent Document 1 further discloses a method of eliminating the gap between the rods by integrally bundling the vicinity of the injection surface and heat-sealing.

JP 2012-113971 (paragraphs 0026, 0040 to 0043, FIG. 6B)

  However, although there is no gap between the rods, there is an economic inconvenience that a cost corresponding to an increase in the number of processing steps due to heat fusion occurs. Further, since the plurality of heat-sealed rods cannot be separated, there is an economical disadvantage in that all rods must be replaced with new ones even if one of them is broken due to breakage or the like. An object of the present invention is to solve the above-described disadvantages and provide a simplified and inexpensive optical component, a light guide member used therefor, and a light irradiation apparatus using the optical component. Another object is to make it possible to separate the bound light guide members.

(Characteristics of the invention of claim 1)
The optical component according to the invention of claim 1 (hereinafter referred to as “optical component of claim 1”) has an entrance surface and an exit surface, respectively, at least at one place between the entrance surface and the exit surface. It is an optical component formed by bundling a plurality of light guide members having a bent portion (R) in a state where the incident surfaces are separated from each other by the bent portion. A plurality of rod-shaped light guide members having an incident surface on which light is incident and an exit surface from which light is emitted, and having a bent portion (R) at least at one position between the incident surface and the exit surface; The optical component is configured such that when the light guide members are bundled, the incident surfaces are separated from each other by the bent portion. Here, on each side surface of the light guide member, a contact surface continuous with the emission surface is formed between the bent portion, and the contact surfaces contact each other when the light guide members are bound to each other. The incident surface is formed so that the total area of the exit surface is smaller than the total area of each of the entrance surfaces , and the entrance surface is formed in a circular shape with a radius R, and the light guide members are bound to each other. In this case, each of the emission surfaces is formed so that the shape of the surface from which the combined light is emitted is a circle having a radius R. Each of the plurality of light guide members may have the same shape or different shapes (length, thickness, bending condition of the bent portion, etc.). The constituent materials of the light guide members can be different, but are preferably the same. This is because if different components are used, the light to be emitted may be adversely affected due to a difference in refractive index. The contact surface is preferably a flat surface. This is because if it is a flat surface, it is difficult to form a gap between the contact surfaces when they are in contact with each other, so that light leakage can be reduced as much as possible. The bundling of the light guide members may be separable or may not be separable.

  According to the optical component of the first aspect, the light incident from the respective incident surfaces of the plurality of light guide members is emitted as the combined light from each of the bundled emission surfaces. The incident surfaces of the light guide members that are bundled are separated from each other due to the presence of the bent portions (in a straight bar shape, they are adjacent to each other without being separated). Therefore, the light emitting elements and the like arranged corresponding to the respective incident surfaces can be separated, and as a result, the problem of heat generated by the light emitting elements and the like can be avoided. Since the contact surface is continuous with the emission surface, the area of the emission surface is reduced accordingly. That is, the exit surface is also synthesized by contact between the contact surfaces (the same surface may or may not be the same), but the total area of the exit surface is reduced compared to the total area of each incident surface. That is, it is possible to increase the amount of light per unit area on the exit surface along with downsizing. Since the structure is simplified, it can be manufactured with a small number of steps, and is therefore economically advantageous.

(Characteristics of the invention described in claim 2)
An optical component according to the invention of claim 2 (hereinafter referred to as “optical component of claim 2”) is the optical component of claim 1, and the light guide members are bound together by a binding means so as to be separable. It is characterized by. The mechanism and principle of the binding means are not limited as long as they do not contradict the purpose of the present invention.

  According to the optical component of the second aspect, in addition to the function and effect of the optical component of the first aspect, since the light guide members bound at one end can be separated from each other, one or more of the plurality of light guide members are provided. It will be possible to replace only. It is very convenient for replacement or maintenance for damage.

(Characteristics of Claim 3)
An optical component according to a third aspect of the present invention (hereinafter referred to as “optical component of the third aspect”) is the optical component according to the first or second aspect, wherein each of the light guide members is formed in the same shape. It is characterized by being.

  According to the optical component of claim 3, in addition to the function and effect of the optical component of claim 1 or 2, the efficiency of manufacturing and managing the light guide member can be dramatically improved. That is, if at least one of the plurality of light guide members has a different shape, the manufacturing and management are complicated by that amount, but if they are the same, all can be performed collectively.

(Feature of the invention of claim 4)
The optical component according to the invention of claim 4 (hereinafter referred to as “optical component of claim 4”) is the optical component of claim 3, wherein there are two light guide members and when they are bound together It is characterized by having a substantially Y-shaped appearance.

  According to the optical component of the fourth aspect, in addition to the function and effect of the optical component of the third aspect, since it is the most simplified shape for performing a single incident single emission, it is simple and stable in form. ing. Although not intended to prevent other shapes, optical components of this shape are easy to manufacture and easy to use.

(Feature of the invention of claim 5)
An optical component according to a fifth aspect of the present invention (hereinafter referred to as “optical component of the fifth aspect”) is the optical component according to any one of the first to fourth aspects, wherein each of the exit surfaces is replaced with another optical component. It is connected to any one of the incident surfaces in a state where it can transmit light.

  According to the optical component of the fifth aspect, in addition to the function and effect of the optical component according to any one of the first to fourth aspects, if the exit surface of another optical component is connected to the incident surface of the basic optical component, It is possible to increase the number, that is, the number of light emitting elements facing the number. It can be used according to various purposes.

(Characteristics of the invention described in claim 6)
An optical component according to a sixth aspect of the invention (hereinafter referred to as "optical component of the sixth aspect") is an optical component according to any one of the first to fifth aspects, except for the incident surface and the exit surface. An optical reflection layer is formed on at least a part of the above. For example, both the entire side surface and the contact surface, or only the entire side surface correspond to at least a part of the outer surface.

  According to the optical component of the sixth aspect, in addition to the operational effects of the optical component according to any one of the first to fifth aspects, the optical reflection layer prevents leakage of incident light, so that the loss of the entire optical component is suppressed. .

(Feature of the invention of claim 7)
A light guide member according to the invention of claim 7 (hereinafter referred to as “light guide member of claim 7”) is a light guide member used for an optical component according to any one of claims 1 to 6.

  According to the light guide member of the seventh aspect, the effect of the optical component according to any one of the first to sixth aspects can be obtained by binding a plurality of light guide members.

(Characteristics of the invention described in claim 8)
A light irradiation apparatus according to an eighth aspect of the present invention (hereinafter referred to as “irradiation apparatus of the eighth aspect”) emits light to be incident on each of the optical component according to any one of the first to sixth aspects and the incident surface. And a light-emitting element.

  According to the irradiation device of the eighth aspect, the function and effect of the optical component according to any one of the first to sixth aspects can be obtained by the optical component according to any one of the first to sixth aspects and the light emitting element.

(Feature of the invention of claim 9)
The light irradiation apparatus according to the ninth aspect of the invention (hereinafter referred to as “irradiation apparatus of the ninth aspect”) is the irradiation apparatus according to the eighth aspect, wherein integration is performed at a position where light emitted from each of the emission surfaces is incident. An optical system is provided.

  According to the irradiating device of claim 9, in addition to the function and effect of the irradiating device of claim 8, it is possible to irradiate light with uniform surface illuminance and spectral distribution by providing an integrating optical system.

  According to the present invention, it is possible to provide a simplified and inexpensive optical component, light guide member, and light irradiation device.

It is an external view of the light guide member which comprises some optical components. It is a top view showing a mode that the light of two light emitting elements is synthesize | combined using the optical component which consists of two light guide members. It is a top view showing a mode that the optical component which consists of six light guide members is combined, and the light of four light emitting elements is synthesize | combined. It is an external appearance perspective view of the light irradiation apparatus incorporating an optical component. It is an electrical block diagram of a light irradiation apparatus.

The optical component (light guide member) according to this embodiment will be described with reference to the drawings.
First, referring to FIG. 1, a light guide member 200 constituting a part of the optical component 100 will be described. FIG. 1B is a front view of the light guide member 200, FIG. 1A is a left side view thereof, FIG. 1C is a right side view thereof, and FIG. It is a bottom view.

(Structure of light guide member)
The light guide member 200 is made of a cylindrical optical glass, and as will be described later, an optical component 100 that exhibits a Y-shaped appearance by binding a plurality of (two in this embodiment) the light guide members 200 (see FIG. 2). That is, the light guide member 200 has a shape in which the Y-shaped optical component 100 is divided into left and right vertical halves along the central axis.

The material which comprises the light guide member 200 will not be ask | required as long as there is little loss and the change of a spectral characteristic, for example, when optical glass and other light pass. For example, a chemical resin such as acrylic may be used as a material, or a natural material such as quartz or rock salt may be used.

  The light guide member 200 is basically composed of a rod-shaped member having a circular section and having a bent portion 205 in the middle (in the present embodiment, approximately in the center in the length direction). One end face of the light guide member 200 is an incident face 201 on which light is incident, and the other end face is an exit face 202 on which light is emitted. The incident surface 201 is, for example, a surface with a radius R having an area for receiving light from the light emitting portion of the light emitting element 150 so that light from the light emitting element 150 (FIG. 2) is incident upon use. It is. A portion between the incident surface 201 and the bent portion 205 is referred to as an incident-side body portion 206, and a portion between the exit surface and the bent portion is referred to as an exit-side body portion 207. The reason why the bent portion 205 is formed is to make it easier to dissipate heat by separating the plurality of incident surfaces 201 of the optical component 100 from each other.

  In the present embodiment, the incident surface 201 is perpendicular to the central axis of the incident-side body 206. This is because light from the light-emitting element 150 (FIG. 2) is incident on the incident surface 201 at a right angle and travels in parallel along the central axis of the incident-side body 206 in order to reduce light loss. . However, for example, the incident surface 201 is inclined with respect to the central axis of the incident-side body 206 when it is unavoidable due to size restrictions derived from the outer dimensions of the light irradiation device 300 described later or requests for optical design. It may be. In that case, since the light from the light emitting element 150 is incident on the incident surface 201 at an angle, a loss at the incident surface 201 may be slightly generated. The length of the incident side body portion 206 is preferably short in order to reduce optical loss. However, as shown in FIG. 2, it is desirable to select an appropriate length in order to arrange the radiator 160 with sufficient space. This is because if the heat radiator 160 is densely arranged, the heat radiation effect is weakened and the light emitting element 150 may be overheated.

  A flat surface (contact surface 204) parallel to the central axis is formed in the entire length direction of the injection-side body 207, that is, between the bent portion 205 and the injection surface 202. As will be described later, the contact surface 204 is a surface that is brought into contact with the contact surface 204 of another light guide member 200 to be bound. The reason why the contact surface 204 is a flat surface is not to prevent the surface from being formed into another shape (for example, a curved surface), but to prevent a gap from being generated between the contact surfaces 204 when they are brought into contact. is there. The reason why the contact surface 204 is parallel to the central axis in combination with the flat surface is that by doing so, all of the light guide member 200 can have the same shape. Since the contact surface 204 of the present embodiment is formed so as to include the central axis, the exit surface 202 has a semicircular cross section with a radius R (FIG. 1C). Furthermore, the contact surface 204 is positioned so that the central axis included in the contact surface 204 and the central axis of the incident-side body 206 are located on the same straight line when the light guide member 200 is viewed from the bottom (FIG. 1D). Is formed. This is because it is not indispensable to be a straight line, but the distance between the incident surfaces 201 can be most separated when bound by being a straight line. In other words, it is considered the most advantageous for preventing overheating. The exit surface 202 is perpendicular to the central axis of the exit side body 207. The reason is the same as the reason why the incident surface 201 is formed at a right angle to the central axis. The length of the exit side body 207 is preferably as short as possible in order to reduce optical loss, and it is not different from the case of the entrance side body 206.

  As shown in FIG. 1B, the central axis of the incident-side body 206 and the central axis of the exit-side body 207 form an angle θ (the bending angle of the bent portion 205) (FIG. 1B). As described above, both the central axes are located on the straight line in the bottom view. In the present embodiment, the angle θ = 30 to 45 degrees. Although it is not intended to exclude angles other than this range, in order to emit light incident from the incident surface 201 from the exit surface 202 with a small loss, θ should be reduced so that the light can travel straight. This is a result of considering that it is desirable and that there is a request from the arrangement of the light emitting element 150 and the radiator 160 as shown in FIG. Moreover, although the incident side trunk | drum 206 and the emission side trunk | drum 207 shown in FIG. 1 make the angle (theta) in the shape of a broken line, you may make an angle (theta) by making a rounded curve. In other words, the bent portion 205 may be bent in a curved shape. In addition, the bent portion 205 does not necessarily have to be one place, and may be two or more places.

  In this embodiment, the incident surface 201 and the exit surface 202 are not subjected to surface processing, but an optical coating that is applied to glasses or a camera lens may be applied to reduce the loss of incidence or exit. Reference numeral 203 shown in FIG. 1 indicates a surface (body surface) formed by combining the entire surface of the entrance-side body 206 of the light guide member 200 and the surface of the exit-side body 207 excluding the contact surface 204. The body surface 203 is subjected to a metal film surface treatment in order to form an optical reflection layer so as not to allow light incident from the incident surface 201 to escape. As a result, the incident light travels to the exit surface 202 while being reflected inside the optical component 200. The treatment applied to the body surface 203 is not limited to the above-described metal coating surface treatment, as long as it can fulfill the function of reflecting light returning from the inside of the light guide member 200 (optical component 100) and returning it to the inside. A process such as covering with a material having a different refractive index or applying a paint having a light reflecting function may be used. This may or may not be performed for the surface treatment for light reflection on the contact surface 204.

(Configuration of optical components)
With reference to FIG. 1A and FIG. 1B, the configuration of the optical component will be described. As described above, the optical component 100 is formed by bundling the two light guide members 200 in a state where the contact surfaces 204 face each other and contact each other. The bundling is performed in a separable manner by the bundling means, but the bundling means is not shown. As described above, when the two light guide members 200A and 200B are closely bonded together with the contact surfaces 204 facing each other, the optical component 100 having a Y-shaped appearance is configured. Next, the light emitting surface of the light emitting element 150 is disposed close to the incident surfaces 201A and 201B of the light guide members 200A and 200B. If there is no problem such as overheating, the light emitting element 150 may be in close contact with each of the incident surfaces 201A and 201B. In FIG. 1A, a heat radiator 160 is attached to each light emitting element 150. It is preferable to arrange the two radiators 160 at intervals so that the heat dissipation performance does not deteriorate. The radiator 160 is not essential for the present invention, and may be omitted if it is not necessary to radiate the light emitting element 150. Light emitted from the two light emitting elements 150 enters the light incident surface 201A of the light guide member 200A and the light incident surface 201B of the light guide member 200B, and is emitted from the light emission surfaces 202A and 202B while traveling straight or reflecting on the body surface 203. The The symbol L shown in FIG. 2 indicates the emitted combined light.

  A configuration for synthesizing light from the four light emitting elements 150 will be described with reference to FIG. Here, six light guide members 200A, 200B, 200C, 200D, 200E, and 200F are prepared. A pair of light guide members 200A and 200B, a pair of light guide members 200C and 200D, and a pair of light guide members 200E and 200F are bound with their contact surfaces 204 facing each other (the binding means is shown in the figure). (Omitted). At this point, each pair constitutes an optical component, and the whole shown in FIG. 3 is also one optical component. By connecting a light guide member to this optical component, a larger optical component can be obtained. Returning now to FIG. The light emission members 202C and 202D of the pair of light guide members 200C and 200D are brought into contact with the incident surface 201A of the light guide member 200A so as to transmit light. Further, the light emission members 202E and 202F of the pair of light guide members 200E and 200F are brought into contact with the incident surface 201B of the light guide member 200B so as to transmit light. The light emitting surfaces of the four light emitting elements 150 are arranged close to the incident surfaces 201C, 201D, 201E, and 201F. The light emitted from the four light emitting elements 150 enters from the incident surfaces 201C, 201D, 201E, and 201F, is combined and emitted from the emission surfaces 202C, 202D, 202E, and 202F, and the incident surfaces 201A of the light guide members 200A and 200B. Enter 201B. Light entering the light guide members 200A and 200B is emitted from the emission surfaces 202A and 202B. This light is a combination of the light from the four light emitting elements 150.

  When combining the light from the three light emitting elements 150, the light guide members 200E and 200F are removed from the structure for combining the light from the four light emitting elements 150, and the light emitting surfaces of the three light emitting elements 150 are removed. Is placed close to the incident surfaces 201C, 201D and 201B. If the three light emitting elements 150 are turned on in this state, the combined light is emitted from the emission surfaces 202A and 202B. When combining light from five or more light emitting elements 150, the number of optical components 100 may be increased, and the exit surface 202 and the entrance surface 201 may be combined according to the above.

  When the light emitting elements 150 having different emission spectral characteristics or the same emission spectral characteristics are combined to obtain light having spectral characteristics uniformly synthesized from the emission surface 202, and when obtaining light having uniform emission surface illuminance An integrating optical system may be inserted after the surface 202. For example, an optical system called a rod lens or fly-eye lens.

  In addition, although the cross section of the optical component 200 in this embodiment was circular in the incident side trunk | drum 206 and semicircular in the emission side trunk | drum 207, shapes other than this are not excluded. That is, the incident-side body 206 may be, for example, a polygon, a polygon with rounded corners, an ellipse, or a semi-ellipse, and the exit-side body 207 may be formed by halving these shapes. Furthermore, although there are two light guide members 100 constituting the optical component 200 in the present embodiment, a plurality of light guide members 100, that is, three or more light guide members 100 may be used. Needless to say, each light guide member in the case of three or more has a bent portion, a contact surface, or the like having a shape capable of realizing the number.

(Configuration of light irradiation device)
An example of the light irradiation apparatus 300 using the optical component 200 will be described with reference to FIGS. A light irradiation apparatus 300 shown in FIG. 4 has a box-shaped housing 302 and includes one or more optical components 100 and a circuit block shown in FIG. 5 (omitted in FIG. 5). An emission hole H that emits light is provided on the front surface of the housing 302, and an emission surface 202 (FIG. 1) of the optical component 100 is disposed behind the emission hole H. The user connects an optical fiber bundle to the emission hole H or inserts a lens to guide the light from the light irradiation device 300 to the outside for use. In addition, an operation unit 320 and a display unit 330 are arranged on the front side, and each receives power ON / OFF, increase / decrease and operation of irradiation light from the user, operation status of the light irradiation apparatus 300 to the user, and the like. Display information of. The operation unit 320 and the display unit 330 may be outside the light irradiation apparatus 300 by using a wired or wireless communication line. In this case, the user can perform an operation at a place away from the light irradiation device 300 and obtain information such as an operation status. It is also possible to control the light irradiation device 300 by connecting it to a sequencer or an industrial personal computer via a communication line (not shown).

  FIG. 5 is a block diagram of the light irradiation apparatus 300. In the present embodiment, the control unit 310 is mainly composed of electronic components in which a control circuit called 1ChipCPU, a memory circuit, and an input / output circuit are combined into one integrated circuit. The control unit 310 receives a user instruction via the operation unit 320 according to a control program written in the 1Chip CPU, drives the display unit 330 to display information such as an operation status, and drives the cooling unit 340. The entire light irradiation apparatus 300 is controlled by cooling each part or driving the light emitting element driving unit 360 to drive the light emitting element 150. As shown in FIG. 4, the operation unit 320 includes a switch that can be operated by the user. The user performs power ON / OFF, increase / decrease of irradiation light, setting of irradiation time, and the like via the operation unit 320. As shown in FIG. 4, the display unit 330 includes a display element that can be visually confirmed by a user, such as a 7-segment LED or a liquid crystal panel. The user obtains information such as the output state of the irradiation light, the operation time of the light irradiation apparatus 300, and the internal temperature of the housing via the display unit 330. The cooling unit 340 is a device that cools the light irradiation device 300 and its components. A cooling fan that cools air by taking air into the housing from the outside, a heat pipe that circulates a heat medium such as chlorofluorocarbon, and a liquid cooling system that circulates a coolant such as water can be used. The power supply unit 350 supplies power to the light irradiation device 300 and its components. A commercial power supply such as an AC 100V power supply may be received from the outside of the light irradiation apparatus 300, converted into a power form suitable for each part of the light irradiation apparatus 300, and a battery may be provided inside the light irradiation apparatus 300. You may have it and supply from there.

  The light emitting element driving unit 360 drives the light emitting element 150 to light up under the control of the control unit 310. When the light emitting element 150 is a light emitting diode (abbreviated as LED), direct current lighting is desirable so that the irradiated light does not fluctuate with time. Further, constant current drive or constant power drive is desirable so that it is not easily affected by temperature changes. In the case where the light emitting element 150 is other than the LED, it is desirable to have a function of performing the driving so that the light to be irradiated does not fluctuate with time after following the rating of the light emitting element 150. For example, feedback driving. There may be a plurality of light emitting element driving units 360, and the light emitting elements 150 are individually driven under the control of the control unit 310. The plurality of light emitting elements 150 may have the same electrical and optical characteristics, or may have different characteristics. If you use multiple materials with the same characteristics, you can expect an increase in the overall light intensity with the same spectral characteristics, and if you combine them with different characteristics, for example, you can combine the three primary colors by combining red, green, and blue emission colors. Can get the light. The control unit 310 appropriately controls the light emitting element driving unit 360, so that even if it is light of the three primary colors, red becomes a strong light or a bluish light, and has the spectral characteristics desired by the user. Can get light.

100 Optical component 150 Light emitting element 160 Radiator 200, 200A, 200B, 200C, 200D, 200E, 200F Light guide member 201, 201A, 201B, 201C, 201D, 201E, 201F Incident surface 202, 202A, 202B, 202C, 202D, 202E, 202F Ejection surface 203 Trunk surface 204 Contact surface 205 Bending portion 206 Incident side trunk portion 207 Ejection side trunk portion 300 Light irradiation device 302 Housing 310 Control unit 320 Operation unit 330 Display unit 340 Cooling unit 350 Power source unit 360 Light emitting element driving Part

Claims (9)

A light guide member including a plurality of rod-shaped light guide members having an incident surface on which light is incident and an exit surface from which light is emitted, and having a bent portion at least at one position between the incident surface and the exit surface; In an optical component configured such that the incident surfaces are separated from each other by the bent portion when bound together,
On each side surface of the light guide member, a contact surface continuous with the emission surface is formed between the bent portion,
The contact surfaces are formed so as to be in contact with each other when the light guide members are bound together,
The total area of the exit surface is reduced compared to the total area of each of the entrance surfaces , and
The entrance surface is formed in a circular shape with a radius R, and each of the exit surfaces is formed so that the shape of the surface from which the combined light is emitted when the light guide members are bound to each other is a circle with a radius R. An optical component characterized by that. The optical component according to claim 1, wherein the light guide members are detachably bound by a binding unit. Each of the said light guide members is formed in the same shape. The optical component of Claim 1 or 2 characterized by the above-mentioned. There are two light guide members,
The optical component according to claim 3, wherein the optical component is configured to exhibit a substantially Y-shaped appearance when bound. 5. The optical component according to claim 1, wherein each of the exit surfaces is connected in a state where it can transmit light with any of the incident surfaces of the other optical components. The optical component according to claim 1, wherein an optical reflection layer is formed on at least a part of the surface excluding the incident surface and the exit surface.   The light guide member used for the optical component in any one of Claims 1 thru | or 6. An optical component according to any one of claims 1 to 6,
And a light emitting element that emits light to be incident on each of the incident surfaces. The light irradiation apparatus according to claim 8, wherein an integrating optical system is provided at a position where light emitted from each of the emission surfaces is incident.

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