JP7615491B2 - Lighting system, lighting method, and lighting system design method - Google Patents

Description

The present disclosure relates to a lighting system, a lighting method, and a method for designing a lighting system.

Laser light sources that emit coherent light are sometimes used as the light source for lighting devices. Laser light sources generally have a smaller light-emitting spot size and higher brightness than LEDs (Light Emitting Devices). In addition, because they emit coherent light, they can increase directionality and allow a sufficient amount of light to reach far distances. Furthermore, by using various optical elements such as diffractive optical elements and lens arrays, as well as microdisplays, it is possible to precisely control the light distribution.

By combining such a laser light source with an optical element, an illumination device that projects a desired projection pattern, as described in Patent Document 1, has been proposed. In the illumination device disclosed in Patent Document 1, laser light generated by a single light source is diffracted by a single optical element such as a hologram. The desired projection pattern is formed from the light from the single light source by diffraction by the optical element. This projection pattern is projected onto a projection surface spaced from the illumination device.

When a laser light source and a diffractive optical element are used as the light source of the lighting device, the desired projection pattern can be projected without using an imaging optical system. In addition, when a laser light source is used as the light source of the lighting device, the divergence angle of the light projected from the lighting device can be reduced. As a result, the projection pattern projected onto the projection surface can be displayed more efficiently and clearly than when an LED is used as the light source.

JP 2015-132707 A

However, information about the projection pattern projected by the lighting device can sometimes be difficult for an observer to recognize when observing the projection pattern. In particular, when the projection pattern extends in one direction, it is difficult to recognize the projection pattern in that direction at a glance. The purpose of the present disclosure is to allow an observer to properly recognize information about the projection pattern.

The lighting system of the present disclosure comprises:
A projection surface;
a lighting device that projects a projection pattern including information onto the projection surface,
the projection pattern is intended to be viewed from a predetermined viewing position spaced from the projection surface;
the projection pattern has a plurality of element patterns arranged in one direction from a predetermined position spaced in one direction from an intersection position with a perpendicular line dropped from the observation position to the projection surface, to an opposite side from the intersection position,
an angle formed by a line connecting each of the two ends of the projection pattern in the one direction and the observation position is 10° or less;
The angle formed by the lines connecting the observation position to both ends of each element pattern in the one direction is 5° or less.

In the lighting system of the present disclosure, the angle between the lines connecting each of the two ends of the projection pattern in one direction and the observation position may be 3° or more.

In the lighting system of the present disclosure, the angle formed by the lines connecting each of the two ends of each element pattern in one direction to the observation position may be 0.1° or more.

In the lighting system of the present disclosure, the angle formed by the lines connecting the observation position to both ends of each element pattern in the other direction that is not parallel to the one direction may be 5° or less.

In the lighting system of the present disclosure, the angle formed by the lines connecting the observation position to both ends of each element pattern in the other direction that is not parallel to the one direction may be 0.1° or more.

In the lighting system of the present disclosure, each of the multiple element patterns may contain the same information.

In the illumination system of the present disclosure, the illumination device may have a light source that emits coherent light, and a diffractive optical element that diffracts the coherent light from the light source to form the projection pattern.

A first illumination method of the present disclosure is an illumination method for projecting a projection pattern onto a projection surface by an illumination device, comprising:
determining a viewing position at which the projection pattern is viewed;
determining a position of the illumination device relative to the projection surface;
and determining the projection pattern projected from the illumination device based on the relationship between the observation position and the placement position.

A second illumination method of the present disclosure is an illumination method for projecting a projection pattern onto a projection surface by an illumination device, comprising:
determining a viewing position at which the projection pattern is viewed;
determining the projection pattern to be projected from the illumination device;
and determining a placement position of the illumination device relative to the projection surface based on the relationship between the observation position and the projection pattern.

A method for designing an illumination system according to the present disclosure is a method for designing an illumination system that projects a projection pattern onto a projection surface by an illumination device, the method comprising the steps of:
determining a viewing position at which the projection pattern is viewed;
determining an observation pattern observed from the observation position;
determining the projection pattern based on the observation position and the observation pattern;
determining a position of the illumination device relative to the projection surface;
determining a light distribution pattern emitted from the lighting device such that the projection pattern is projected from the lighting device onto the projection surface based on a relationship between the observation position and the placement position;
and designing a diffractive optical element included in the lighting device so as to form the light distribution pattern.

This disclosure allows the observer to properly recognize the projection pattern information.

FIG. 1 is a perspective view that illustrates a schematic configuration of a lighting system. FIG. 2 is an enlarged plan view of the illumination system observed from the normal direction of the projection plane. FIG. 3 is a diagram showing a state in which a projection pattern projected by the illumination system is observed by an observer. FIG. 4 is a diagram showing a state in which element patterns of a projection pattern projected by an illumination system are observed by an observer. FIG. 5 is a diagram showing a state in which element patterns of a projection pattern projected by an illumination system are observed by an observer when observed from a direction different from that shown in FIG.

An embodiment of the present disclosure will be described below with reference to the drawings. Note that in the drawings attached to this specification, the scale and aspect ratios have been appropriately altered and exaggerated from those of the actual objects for the convenience of illustration and ease of understanding.

In addition, terms used in this specification that specify shapes, geometric conditions, and their degrees, such as "parallel," "orthogonal," and "same," as well as values of length and angle, are not bound by strict meanings, but are interpreted to include the range in which similar functions can be expected.

Figure 1 is a perspective view showing a schematic configuration of a lighting system 1 according to the present embodiment. As shown in Figure 1, the lighting system 1 has a projection surface 3 and a lighting device 10. In the lighting system 1, a projection pattern 4 is projected onto the projection surface 3 by the lighting device 10.

The projection surface 3 functions as a display surface that displays the projection pattern 4 projected from the lighting device 10 so that it can be properly observed by surrounding observers. The projection surface 3 is a surface spaced apart from the lighting device 10. The projection surface 3 is preferably a flat surface so as to properly display the projection pattern 4. As shown in FIG. 1, in this embodiment, the projection surface 3 has a predetermined width in the first direction d1 and extends in the second direction d2. Such a projection surface 3 is, for example, a part of the road surface of a road or a passage. The length (width) of the projection surface 3 in the first direction d1 and the length in the second direction d2 are determined by the light distribution pattern of the light diffracted by the diffractive optical element 14 of the lighting device 10 (described later) and the positional relationship between the projection surface 3 and the lighting device 10. In the illustrated example, the first direction d1 and the second direction d2 are perpendicular to each other.

Projection pattern 4 is a predetermined pattern that is displayed on projection surface 3 and observed by the observer. Projection pattern 4 includes, for example, predetermined information for the observer to observe. In the example shown in FIG. 1, projection pattern 4 includes multiple arrows for route guidance or the like as the predetermined information. However, the information included in projection pattern 4 is arbitrary, and may include not only symbols such as arrows, but also pictures, images, letters, numbers, and the like. In addition, the display color, size, character line type, and line width of the predetermined information are also arbitrary, and at least a portion of the predetermined information may be color-coded in multiple colors.

As shown in Figs. 3 and 4, the projection pattern 4 is intended to be observed by an observer from a predetermined observation position 7. That is, at the observation position 7, the projection pattern 4 is properly observed. For example, at the observation position 7, the observer can observe the entire projection pattern 4. The projection pattern 4 is observed as an observation pattern by the observer. For example, when the observer observes the entire projection pattern 4 as an observation pattern of approximately the same size, the projection pattern 4 becomes larger as it moves away from the observation position 7. The observation position 7 is spaced apart from the projection surface 3. The length by which the observation position 7 is spaced apart from the projection surface 3 is, for example, the eye height of a person standing upright on the projection surface 3, or the eye height of a passenger of a moving body such as a car located on the projection surface 3. The length by which the observation position 7 is spaced apart from the projection surface 3 is, for example, 70 cm or more and 250 cm or less.

The projection pattern 4 has a plurality of element patterns 5. The plurality of element patterns 5 are arranged in the second direction d2. In particular, the direction in which the plurality of element patterns 5 are arranged is the front-to-back direction with respect to the observer. That is, as shown in Figures 3 and 4, the plurality of element patterns 5 are arranged in the second direction d2 from a predetermined position 9 spaced in the second direction d2 from an intersection position 8 with a perpendicular line dropped from the observation position 7 on the projection surface 3 to the opposite side of the intersection position 8. The observer can simultaneously observe the plurality of element patterns 5 arranged in the second direction d2.

The element pattern 5 contains a portion of the information of the projection pattern 4. The multiple element patterns 5 may each contain different information, or each may contain the same information. For example, as shown in FIG. 1, the multiple element patterns 5 may each contain the same information, such as an arrow for route guidance. In this case, the direction and size of the arrow may be different for the same route guidance information. In this way, even if the multiple element patterns 5 contain the same information, the element patterns 5 may have different sizes, shapes, etc.

Projection pattern 4 contains light with wavelengths in the visible light wavelength range so that it can be observed by an observer. Specifically, projection pattern 4 contains light with wavelengths of 380 nm or more and 700 nm or less. In addition, simultaneously with projection pattern 4, lighting device 10 may irradiate light outside the visible light wavelength range, such as light in the infrared range, light in the ultraviolet range, millimeter waves, or terahertz waves.

The lighting device 10 is a device that projects the projection pattern 4 onto the projection surface 3. In this embodiment, the lighting device 10 is used as a part of a stationary information display light. However, the lighting device 10 can also be applied to various lighting lamps such as searchlights. Such a lighting device 10 is installed, for example, on the ceiling surface or wall surface of a building. The lighting device 10 can also be mounted on various moving objects, that is, it can be applied not only to vehicles such as automobiles and bicycles, but also to moving objects such as ships, airplanes, and trains. Furthermore, the lighting device 10 can be applied to terminals that can display information, such as computer displays, mobile terminals such as tablets and smartphones, and televisions. In this way, the lighting device 10 includes not only those that are installed at a predetermined position as in this embodiment, but also those that move. In particular, the lighting device 10 may be carried by the observer who observes the projection pattern 4 projected by the lighting device 10. The lighting device 10 is placed at a predetermined placement position 11 where the projection pattern 4 can be appropriately projected onto the projection surface 3. In other words, the lighting device 10 placed at the placement position 11 projects the projection pattern 4 onto the projection surface 3 in an appropriate direction and with an appropriate resolution.

As shown in FIG. 1, the lighting device 10 has a light source 12, a shaping optical system 13, and a diffractive optical element 14. The lighting device 10 may further have a housing that houses the light source 12, the shaping optical system 13, and the diffractive optical element 14. Each of the components of the lighting device 10 will be described below.

The light source 12 emits coherent light, which is light with a uniform wavelength and phase. Various types of light sources can be used as the light source 12. Typically, a laser light source that oscillates laser light can be used as the light source 12 that emits coherent light. As a specific example, the light source 12 is configured as a semiconductor laser light source and is supported by, for example, a circuit board. In the example shown in FIG. 1, three light sources 12 are provided, each emitting light of a different wavelength. The wavelength of the light emitted by the light source 12 corresponds to the wavelength of the light contained in the projection pattern 4. For example, when the projection pattern 4 is projected so as to include light in the visible light wavelength range, the light source 12 emits light in the visible light wavelength range. In this case, typically, the three light sources 12 emit coherent light in the red, green, and blue wavelength ranges, respectively. The light source 12 may also emit light other than the visible light wavelength range, for example, light in the infrared range, light in the ultraviolet range, millimeter waves, or terahertz waves. It should be noted that the illustrated example is not limiting, and the number of light sources 12 may be any number.

The shaping optical system 13 shapes the light emitted from the light source 12. In other words, the shaping optical system 13 shapes the shape of the light from the light source 12 in a cross section perpendicular to the optical axis and the three-dimensional shape of the light radiation space. Typically, the shaping optical system 13 expands the cross-sectional area of the projected light in a cross section perpendicular to the optical axis of the light. In particular, in the illustrated example, the shaping optical system 13 shapes the light emitted from the light source 12 into a widened parallel light. That is, the shaping optical system 13 functions as a collimating optical system. As shown in FIG. 1, the shaping optical system 13 has a first lens 13a and a second lens 13b in the order along the optical path of the coherent light. The first lens 13a shapes the light emitted from the light source 12 into a diverging light. The second lens 13b reshapes the diverging light generated by the first lens 13a into a parallel light. That is, the second lens 13b functions as a collimating lens. In the example shown in FIG. 1, multiple shaping optical systems 13 are provided. The shaping optical systems 13 are provided corresponding to each light source 12. Therefore, the number of shaping optical systems 13 is the same as the number of light sources 12.

The diffractive optical element 14 diffracts the light that has passed through the shaping optical system 13 to form the projection pattern 4. The light diffracted by the diffractive optical element 14 is projected onto the projection surface 3. In the example shown in FIG. 1, multiple diffractive optical elements 14 are provided. The diffractive optical elements 14 are provided corresponding to each shaping optical system 13. Therefore, the number of diffractive optical elements 14 is the same as the number of shaping optical systems 13.

In FIG. 2, one diffractive optical element 14 is shown enlarged. As shown in FIG. 2, the diffractive optical element 14 includes a plurality of element diffractive optical elements 15. In particular, the plurality of element diffractive optical elements 15 are minute thin plate-like members, and are two-dimensionally arranged on the same plane in the diffractive optical element 14 without gaps. The element diffractive optical element 15 diffracts light and emits it from the emission surface 15a. Each of the plurality of element diffractive optical elements 15 diffracts light from the shaping optical system 13 to form a light distribution pattern. This light distribution pattern is projected onto the projection surface 3 to form the projection pattern 4. Each element diffractive optical element 15 may form the entirety of the predetermined information displayed by the projection pattern 4, or may form a part of the predetermined information.

The diffraction characteristics of each element diffractive optical element 15 are designed to properly illuminate each illumination range of the corresponding projection surface 3, so that the specified information displayed by the projection pattern 4 projected onto the projection surface 3 can be properly displayed.

As shown in FIG. 2, the diffraction characteristics of each element diffractive optical element 15 are adjusted so that the irradiation width w along the first direction d1 of light diffracted by one element diffractive optical element 15 incident on an arbitrary position along the second direction d2 of the projection surface 3 is the same as the irradiation width w along the first direction d1 of light diffracted by another element diffractive optical element 15 incident on an arbitrary position along the second direction d2 of the projection surface 3.

The element diffractive optical element 15 is typically a hologram element. By using a hologram element as the element diffractive optical element 15, it becomes easier to design the diffraction characteristics, and it is relatively easy to design a hologram element that can display information of a predetermined position, size, and shape on the projection surface 3.

When the element diffractive optical element 15 is constructed of a hologram element, the above-mentioned diffraction characteristics can be designed relatively easily using a computer by using a computer generated hologram (CGH).

The element diffractive optical element 15 may be a phase type diffractive optical element or an amplitude type diffractive optical element. Furthermore, although the element diffractive optical element 15 is configured as a transmission type in the example shown in FIG. 1, it may be configured as a reflection type. When the element diffractive optical element 15 is configured as a phase type diffractive optical element, the fine structure constituting the element diffractive optical element 15 can adopt a concave-convex pattern structure in which the optical path length changes depending on the incident position of light, or a pattern structure in which the refractive index differs depending on the incident position of light. A fine structure consisting of a concave-convex pattern is preferable in that it can be mass-produced by resin molding using photolithography technology. Furthermore, when the element diffractive optical element 15 is configured as an amplitude type diffractive optical element, the fine structure constituting the element diffractive optical element 15 can adopt a structure in which the transmittance differs depending on the incident position of light.

Next, the relationship between the projection pattern 4 and the observation position 7 will be explained with reference to Figures 3 to 5.

Figures 3 and 4 show a state in which an observer is observing the projection pattern 4 and multiple element patterns 5 from an observation position 7 in a direction parallel to the projection surface 3. In the illustrated example, the element patterns 5 are arrows for route guidance or the like. In particular, in the illustrated example, multiple element patterns 5, which are arrows of the same shape and size, are lined up in one direction (second direction d2).

The observer can observe the entire projection pattern 4 at a glance at the observation position 7. In other words, the observer can observe the entire projection pattern 4, i.e., all element patterns 5, at the observation position 7 without moving the viewpoint significantly. Since the projection pattern 4 is sufficiently small, the angle at which the observer views the entire projection pattern 4 at the observation position 7, i.e., the angle θ _A formed by the lines connecting the observation position 7 and each of the two ends of the projection pattern 4 in the second direction d2, is sufficiently small. Specifically, the angle θ _A is 10° or less, and preferably 8° or less. Moreover, the projection pattern 4 has a size that allows the observer to easily observe it. Since the projection pattern 4 is sufficiently large, the angle θ _A is sufficiently large. Specifically, the angle θ _A is 3° or more, and preferably 5° or more.

The observer, at the observation position 7, observes each element pattern 5 at angles θ ₁ , θ ₂ , ..., θ _n with respect to the second direction d2. In other words, the observer observes each element pattern 5 at angles θ ₁ , θ ₂ , ..., θ _n formed by lines connecting each end of each element pattern 5 in the second direction d2 with the observation position 7. Here, n is the number of element patterns 5 arranged in the second direction d2, and in the example shown in FIG. 4, n is 4. Each element pattern 5 is sufficiently small in the second direction d2 so that the observer can recognize each element pattern 5 by gazing at it without moving the viewpoint in the second direction d2. Specifically, the angles θ ₁ , θ ₂ , ..., θ _n are 5° or less, and preferably 4° or less. Also, each element pattern 5 is sufficiently large in the second direction d2 so that the observer can properly recognize each element pattern 5 in the second direction d2. Specifically, the angles θ ₁ , θ ₂ , . . . , θ _n are equal to or greater than 0.1°, and preferably equal to or greater than 1°.

5 shows a state in which an observer observes a plurality of element patterns 5 from an observation position 7 in a direction different from that in FIG. 3 and FIG. 4, particularly from the normal direction of the projection surface 3. As shown in FIG. 5, the observer observes each element pattern 5 at an angle φ 1 , φ 2 , ..., φ _{n with respect to the first direction d1 at the observation position 7. In other words, the observer observes each element pattern 5 at an angle φ 1 , φ 2 , ..., φ n formed by a line} connecting each end of each element pattern 5 in the first direction d1 with the observation position 7. Each element pattern ₅ is sufficiently small in the first direction d1 so that the observer can recognize each element pattern 5 by gazing at it without moving the viewpoint in the first direction d1. Specifically, the angles φ ₁ , φ ₂ , ..., φ _n are 5° or less, and preferably 4° or less. Moreover, each element pattern 5 is sufficiently large in the first direction d1 so that an observer can properly recognize each element pattern 5 in the first direction d1. Specifically, the angles φ ₁ , φ ₂ , ..., φ _n are 0.1° or more, and preferably 1° or more.

Next, we will explain the illumination method for projecting the projection pattern 4 onto the projection surface 3 using the illumination device 10.

First, the observation position 7 is determined, which is the position of the person's eyes where the projection pattern 4 is expected to be observed on the projection surface 3. For example, the observation position 7 is determined by determining the position where route guidance should be provided in a passageway or the like, and determining the height of the person's eyes at that position. Next, the arrangement position 11 of the lighting device 10 relative to the projection surface 3 is determined. The arrangement position 11 may be determined independently of the observation position 7, but should be a position where the light projected from the lighting device 10 to the projection surface 3 is not obstructed by the observer positioned at the observation position 7. Then, the projection pattern 4 projected from the lighting device 10 is determined based on the relationship between the observation position 7 and the arrangement position 11. Specifically, the projection pattern 4 is determined so that the entire projection pattern 4 can be observed from the observation position 7, each element pattern 5 of the projection pattern 4 can be recognized, and the lighting device 10 can be projected from the arrangement position 11 to the projection surface 3 with an appropriate size, angle, and shape. The projection pattern 4 projected in this manner is observed by the observer at the observation position 7 as a predetermined observation pattern.

Alternatively, the projection pattern 4 may be projected onto the projection surface 3 by the lighting device 10 as follows. First, as in the above-mentioned lighting method, the observation position 7 is determined, which is the position of the human eye where the projection pattern 4 is expected to be observed on the projection surface 3. Next, the projection pattern 4 to be projected from the lighting device 10 is determined. The projection pattern 4 is determined based on the size, angle, shape, etc. to be observed from the observation position 7. Then, based on the relationship between the observation position 7 and the projection pattern 4, the arrangement position 11 of the lighting device 10 with respect to the projection surface 3 is determined. Specifically, the arrangement position 11 is determined so that the lighting device 10 can project onto the projection surface 3 the projection pattern 4 such that the entire projection pattern 4 can be observed at the observation position 7. The projection pattern 4 projected in this manner is observed by the observer at the observation position 7 as a predetermined observation pattern.

Next, we will explain how to design a lighting system 1 that projects a projection pattern 4 onto a projection surface 3 using a lighting device 10.

First, as in the above-mentioned illumination method, the observation position 7 is determined, which is the position of the human eye where the projection pattern 4 is expected to be observed on the projection surface 3. Next, the observation pattern observed by the observer at the observation position 7 is determined. Then, based on the observation position 7 and the observation pattern, the projection pattern 4 to be projected onto the projection surface 3 by the illumination device 10 is determined. The projection pattern 4 is determined based on the size, angle, shape, etc. to be observed from the observation position 7. Then, the arrangement position 11 of the illumination device 10 with respect to the projection surface 3 is determined. The arrangement position 11 may be determined independently of the observation position 7, but it is a position where the light projected from the illumination device 10 to the projection surface 3 by the observer positioned at the observation position 7 is not obstructed. Then, based on the relationship between the observation position 7 and the arrangement position 11, the light distribution pattern emitted from the illumination device 10 is determined so that the projection pattern 4 is projected from the illumination device 10 onto the projection surface 3. Then, the diffractive optical element 14 of the illumination device 10 is designed to form this light distribution pattern. That is, the diffractive optical element 14 that forms the projection pattern 4 is designed so that the projection pattern 4 is projected onto the projection surface 3 from the lighting device 10 arranged at the arrangement position 11 in such a way that the entire projection pattern 4 can be properly observed from the observation position 7. More specifically, the diffractive optical element 14 is designed so that the light from the lighting device 10 arranged at the arrangement position 11 becomes a light distribution pattern that forms the projection pattern 4 on the projection surface 3 by diffracting the light from the light source 12.

However, when the projection pattern projected by the lighting device extends in one direction, it may be difficult for the observer to recognize the information of the projection pattern in that direction. There is a limit to the range of the human visual field, and even within the visual field, eyesight tends to decrease the further away from the gaze point. The visual field is divided into central vision, where you can gaze at even the smallest details, and peripheral vision, where you can see but cannot recognize it as meaningful information. If part of the projection pattern falls outside the observer's central visual field from the gaze point, it is considered that the observer cannot observe the entire projection pattern at a glance at the observation position, or cannot properly recognize each element pattern of the projection pattern, making it difficult to recognize the information of the projection pattern. On the other hand, if the projection pattern fits within the observer's central visual field, the observer can observe the entire projection pattern at a glance.

In this embodiment, the angle θ _A formed by the lines connecting each of the two ends of the projection pattern 4 in one direction and the observation position 7 is 10° or less. Such an angle range corresponds to the range of the central visual field. Therefore, the observer can observe the entire projection pattern 4 at a glance at the observation position 7. In addition, the angles θ ₁ , θ ₂ , ..., θ _n formed by the lines connecting each of the two ends of the element pattern 5 in one direction and the observation position 7 are 5° or less. Therefore, the observer can properly recognize each element pattern 5 in one direction by gazing at each element pattern 5. In this way, in this embodiment, the entire projection pattern 4 and each element pattern 5 can be properly recognized. This allows the observer to properly recognize the information of the projection pattern 4.

The angle _θA formed by the lines connecting both ends of the projection pattern 4 in one direction with the observation position 7 is 3° or more. Such a projection pattern 4 has a sufficient size in one direction when observed from the observation position 7. Therefore, the observer can easily observe the projection pattern 4 from the observation position 7.

The angles θ ₁ , θ ₂ , ..., θ _n formed by lines connecting both ends of each element pattern 5 in one direction with the observation position 7 are 0.1° or more. Such element patterns 5 are sufficiently large in one direction when observed from the observation position 7. Therefore, the observer can easily recognize the information contained in the element patterns 5 from the observation position 7.

The angles φ ₁ , φ ₂ , ..., φ n formed by the lines connecting the observation position 7 and each of the two ends of the first direction d1 non-parallel to the second direction d2 of each element pattern 5 in the other direction non-parallel to the one direction are 5° or less. Therefore, the observer can properly recognize each element pattern 5 in the other direction by gazing at each element pattern 5. This allows the _observer to properly recognize the information of the projection pattern 4.

The angles φ ₁ , φ ₂ , ..., φ n formed by the lines connecting the observation position 7 and both ends of each element pattern 5 in the other direction non-parallel to one direction, i.e., the first _direction d1 non-parallel to the second direction d2, are 0.1° or more. Such a projection pattern 4 is sufficiently large in the other direction when observed from the observation position 7. Therefore, the observer can easily observe the projection pattern 4 from the observation position 7.

As described above, the lighting system 1 of the present embodiment includes a projection surface 3 and a lighting device 10 that projects a projection pattern 4 including information onto the projection surface 3, the projection pattern 4 is intended to be observed from a predetermined observation position 7 spaced apart from the projection surface 3, the projection pattern 4 has a plurality of element patterns 5 arranged in one direction from a predetermined position 9 spaced apart in one direction from an intersection position 8 with a perpendicular line dropped from the observation position 7 to the projection surface 3, to the opposite side from the intersection position 8, the angle θ _A formed by the line connecting each of both ends of the projection pattern 4 in one direction to the observation position 7 is 10° or less, and the angles θ ₁ , θ ₂ , ..., θ _n formed by the line connecting each of both ends of each element pattern 5 in one direction to the observation position 7 are 5° or less. According to such a lighting system 1, the entire projection pattern 4 and each element pattern 5 can be properly observed by the observer, thereby allowing the observer to properly recognize the information of the projection pattern 4.

The aspects of the present disclosure are not limited to the above-described embodiment, but include various modifications that may be conceived by a person skilled in the art, and the effects of the present disclosure are not limited to the above-described contents. In other words, various additions, modifications, and partial deletions are possible within the scope that does not deviate from the conceptual idea and intent of the present disclosure derived from the contents defined in the claims and their equivalents.

REFERENCE SIGNS LIST 1 illumination system 3 projection surface 4 projection pattern 5 element pattern 7 observation position 8 intersection position 10 illumination device 11 placement position 12 light source 13 shaping optical system 14 diffractive optical element 15 element diffractive optical element

Claims (7)

A projection surface;
a lighting device that projects a projection pattern including information onto the projection surface,
the projection pattern is intended to be viewed from a predetermined viewing position spaced from the projection surface;
the projection pattern has a plurality of element patterns arranged in one direction from a predetermined position spaced in one direction from an intersection position with a perpendicular line dropped from the observation position to the projection surface, to an opposite side from the intersection position,
an angle formed by a line connecting each of the two ends of the projection pattern in the one direction and the observation position is 10° or less;
An illumination system, wherein an angle formed by a line connecting each of the two ends of each element pattern in the one direction and the observation position is 5° or less. The lighting system of claim 1, wherein the angle between the lines connecting the observation position and each of the two ends of the projection pattern in one direction is 3° or more. The lighting system according to claim 1 or 2, wherein the angle formed by the lines connecting the observation position to both ends of each element pattern in the one direction is 0.1° or more. The lighting system according to any one of claims 1 to 3, wherein the angle formed by the lines connecting the observation position and each of the two ends of each element pattern in the other direction that is not parallel to the one direction is 5° or less. The lighting system according to any one of claims 1 to 4, wherein the angle formed by the lines connecting the observation position and each of the two ends of each element pattern in the other direction that is not parallel to the one direction is 0.1° or more. The lighting system according to any one of claims 1 to 5, wherein each of the element patterns contains the same information. The illumination system according to any one of claims 1 to 6, wherein the illumination device includes a light source that emits coherent light, and a diffractive optical element that diffracts the coherent light from the light source to form the projection pattern.