Work vehicle with lighting equipment, lighting equipment, work support equipment and work assistance system

Abstract

This invention relates to a work vehicle equipped with a lighting device, a lighting device, a work support device, and a work assistance system that can easily enable the linear movement of the work vehicle toward a target point. [Solution] The work vehicle 10 with a lighting device comprises a work vehicle 20 that performs work while moving, and a lighting device 30 attached to the work vehicle. The lighting device comprises a light source that emits coherent light and a diffractive optical element that diffracts the coherent light from the light source, and illuminates the illuminated area with the coherent light diffracted by the diffractive optical element. The illuminated area is located in front of the work vehicle in the direction of movement and indicates information related to the direction of movement of the work vehicle.

Description

Technical Field

[0001] The present disclosure relates to a work vehicle with a lighting device, a lighting device, a work support device, and a work assistance system.

Background Art

[0002] As disclosed in Patent Document 1 as an example, work vehicles that perform some work while moving are used in various fields. Examples include work vehicles for producing roads, maintaining roads, performing agricultural work, and maintaining fields. The work vehicle moves by the output from a driving device such as an engine or the force pushed by an operator. The moving direction of the work vehicle is adjusted by an operation by an operator who rides on or pushes the work vehicle or by a remote operation by the operator.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There may be a demand to perform work while moving the work vehicle linearly toward a target point. However, when the target point is far away, for example, when the target point is at a position more than 20 m away, it is not easy to move the work vehicle linearly toward the target point. For example, in a white line drawing machine such as Patent Document 1, the line to be drawn linearly meanders.

[0005] An object of the present disclosure is to easily realize linear movement of the work vehicle toward a target point.

Means for Solving the Problems

[0006] One embodiment of the present disclosure relates to the following [1] to

[38] .

[0007] [1] A work vehicle that performs work while moving, The work vehicle has a lighting device that is attached to it, The illumination device comprises a light source that emits coherent light and a diffractive optical element that diffracts the coherent light from the light source. The lighting device illuminates the area to be illuminated, including the area located in front of the work vehicle in the direction of movement, with coherent light diffracted by the diffractive optical element. The illuminated area is a work vehicle equipped with a lighting device that displays information related to the direction of movement of the work vehicle.

[0008] [2] In the work vehicle equipped with the lighting device of [1], the illuminated area may extend along the direction of movement.

[0009] [3] A work vehicle that performs work while moving, The work vehicle has a lighting device that is attached to it, The illumination device comprises a light source that emits coherent light and a diffractive optical element that diffracts the coherent light from the light source. The lighting device illuminates the area to be illuminated, including the area located in front of the work vehicle in the direction of movement, with coherent light diffracted by the diffractive optical element. The illuminated area is a work vehicle equipped with a lighting device, extending along the direction of movement.

[0010] [4] In any work vehicle equipped with a lighting device according to [1] to [3], the illuminated area may include a linear or dotted line first area extending along the direction of movement.

[0011] [5] In any work vehicle equipped with a lighting device according to [1] to [4], the illuminated area may further include a second area extending in a direction nonparallel to the direction of movement.

[0012] [6] In any of the work vehicles equipped with lighting devices described in [1] to [5], The illuminated region may further include a plurality of second regions extending from the first region in a direction nonparallel to the direction of movement. Multiple second regions may be positioned at intervals in the direction of movement.

[0013] [7] In any of the work vehicles equipped with lighting devices described in [1] to [6], the length of the illuminated area along the direction of movement on the moving surface of the work vehicle may be 3m or more and 100m or less.

[0014] [8] In any of the work vehicles equipped with lighting devices described in [1] to [7], the width of the illuminated area along the direction perpendicular to the direction of movement on the moving surface may be 0.002 m or more and 0.2 m or less.

[0015] [9] In any work vehicle equipped with a lighting device as described in [1] to [8], the ratio of the length of the illuminated area along the direction of movement on the moving surface of the work vehicle to the width of the illuminated area along the direction perpendicular to the direction of movement on the moving surface may be 25 or more and 10000 or less.

[0016]

[10] In any of the work vehicles equipped with lighting devices described in [1] to [9], The lighting device may have a casing for housing the light source. The light source and the diffractive optical element may be fixed to the casing.

[0017]

[11] In any of the work vehicles equipped with lighting devices described in [1] to

[10] , The lighting device may include a casing for housing the light source and a shaping optical system for shaping the light from the light source. The light source, the shaping optical system, and the diffractive optical element may be fixed to the casing.

[0018]

[12] In any work vehicle equipped with a lighting device as described in [1] to

[11] , the lighting device may be mounted on the work vehicle so as to be adjustable in the vertical direction.

[0019]

[13] In any of the work vehicles with a lighting device according to [1] to

[12] , the lighting device may be attached to the work vehicle so that its orientation in the left - right direction can be adjusted.

[0020]

[14] In any of the work vehicles with a lighting device according to [1] to

[13] , the lighting device may be attached to the work vehicle so that its rotational position about an axis non - parallel to both the left - right direction and the up - down direction can be adjusted.

[0021]

[15] In any of the work vehicles with a lighting device according to [1] to

[14] , the lighting device may be attached to the work vehicle so that its position in at least one of the left - right direction and the up - down direction can be adjusted.

[0022]

[16] In any of the work vehicles with a lighting device according to [1] to

[15] , the illuminated area may at least partially include the area where the work is being performed by the work vehicle.

[0023]

[17] In any of the work vehicles with a lighting device according to [1] to

[16] , the illuminated area may at least partially include the area where the work vehicle is located in the moving direction.

[0024]

[18] In any of the work vehicles with a lighting device according to [1] to

[17] , the illuminated area may include the area located behind the work vehicle in the moving direction.

[0025]

[19] A lighting device used for a work vehicle that performs work while moving, A lighting device comprising a light source that emits coherent light and a diffractive optical element that diffracts the coherent light from the light source.

[0026]

[20] Illuminating an illuminated area including an area located in front of the work vehicle in the moving direction with the coherent light diffracted by the diffractive optical element, The illuminated area is an illumination device that displays information related to the direction of movement of the work vehicle.

[0027]

[21] The area to be illuminated, including the area located in front of the work vehicle in the direction of movement, is illuminated by the coherent light diffracted by the diffractive optical element, The illuminated area is an illumination device that extends along the direction of movement.

[0028]

[22] Lighting equipment used in work vehicles that perform work while moving toward a target location, The system comprises a target installed at the aforementioned target location, The aforementioned lighting device is a work support device comprising a light source that emits coherent light and a diffractive optical element that diffracts the coherent light from the light source.

[0029]

[23] A work assistance system according to one embodiment of the present disclosure is Lighting equipment used in work vehicles that perform tasks while moving towards a target location, The optical filter comprises an optical filter whose average transmittance in the wavelength range of coherent light projected from the illumination device is higher than the average transmittance in the visible light wavelength range other than the wavelength range of coherent light. The lighting device illuminates the area to be illuminated, including the area located in front of the work vehicle in the direction of movement, with the coherent light.

[0030] In the work assistance system of

[24]

[23] , the illuminated area may be observed through the optical filter.

[0031]

[25]

[24] The work support system is The work vehicle is equipped with a device that can be worn by the operator of the work vehicle, The aforementioned mounting device includes the optical filter, When the operator is wearing the device, the optical filter may face the operator's eye.

[0032] In the work support system of

[26]

[25] , The mounting device includes a light-shielding wall portion located around the optical filter, When the operator is wearing the device, the light-shielding wall may be positioned between the optical filter and the operator.

[0033] In the work support systems of

[27]

[25] or

[26] , The aforementioned attachment device includes an attachment device body that is attached to the head, The optical filter may be detachable from the mounting device body.

[0034] In the work assistance system of

[28]

[25] , the attachment may include a contact lens containing the optical filter.

[0035] The work assistance systems of

[29]

[23] or

[24] may include an imaging device that includes the optical filter.

[0036]

[30]

[29] The work support system is The imaging device is equipped with a display device that is electrically connected to it, The display device may display the image captured by the imaging device.

[0037] In any of the work assistance systems described in

[31]

[23] to

[30] , the optical filter may include a dielectric multilayer film.

[0038] In any of the work assistance systems described in

[32]

[23] to

[31] , the full width at half maximum of the optical filter may be 15 nm or less.

[0039]

[33] In any of the work assistance systems described in

[23] to

[32] , the maximum transmittance of the optical filter in the visible light range may be 50% or more.

[0040]

[34] In any of the work assistance systems described in

[23] to

[33] , the average transmittance of the optical filter in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of the coherent light may be 1% or less.

[0041] In any of the work assistance systems described in

[35]

[23] to

[34] , the average transmittance of the optical filter in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of the coherent light may be 0.001% or more.

[0042] In any of the work assistance systems described in

[36]

[23] to

[35] , the maximum illuminance of the illuminated area due to the coherent light may be 1 lx or more.

[0043] In any of the work support systems in

[37]

[23] to

[36] , The illuminance LX(lx) is the maximum value of the illuminance of the illuminated area caused by the coherent light, The illuminance LY(lx) at the position within the illuminated area where the illuminance LX is obtained is due to ambient light, The average transmittance TX(%) of the optical filter in the wavelength range of the coherent light, The average transmittance TY(%) of the optical filter in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of the coherent light may satisfy the following relationship. 0.001 ≤ (LX·TX) / (LY·TY)

[0044] In any of the work assistance systems described in

[38]

[23] to

[37] , the illuminance LX, the illuminance LY, the transmittance TX, and the transmittance TY may satisfy the following relationship. (LX·TX) / (LY·TY) ≤ 10 [Effects of the Invention]

[0045] According to this disclosure, it is possible to easily move a work vehicle in a straight line toward a target location. [Brief explanation of the drawing]

[0046] [Figure 1] Figure 1 is a diagram illustrating one embodiment, and is a perspective view showing an example of a work vehicle equipped with a lighting device. [Figure 2A] Figure 2A is a side view showing the work vehicle with lighting equipment shown in Figure 1. [Figure 2B] Figure 2B is a top view of the work vehicle with lighting equipment shown in Figure 2A, illustrating the illuminated area illuminated by the lighting equipment. [Figure 3] Figure 3 is a perspective view corresponding to Figure 1, showing another example of a work vehicle equipped with lighting. [Figure 4A] Figure 4A is a perspective view showing the illuminated area on the moving surface. [Figure 4B] Figure 4B is a perspective view showing the illuminated area on the moving surface. [Figure 4C] Figure 4C is a perspective view showing the illuminated area on the moving surface. [Figure 4D] Figure 4D is a perspective view showing the illuminated area on the moving surface. [Figure 5A] Figure 5A corresponds to Figure 2B and illustrates one modified example of the illuminated area. [Figure 5B] Figure 5B corresponds to Figure 2B and illustrates another modification of the illuminated area. [Figure 6] Figure 6 is a diagram corresponding to Figure 2B, illustrating yet another modification of the illuminated area. [Figure 7] Figure 7 is a diagram corresponding to Figure 2B, illustrating yet another modification of the illuminated area. [Figure 8] Figure 8 is a diagram corresponding to Figure 2A, illustrating a modified example of a work vehicle equipped with a lighting device. [Figure 9] Figure 9 is a diagram corresponding to Figure 2B, and shows the work vehicle with lighting equipment shown in Figure 8. [Figure 10] Figure 10 is a diagram corresponding to Figure 2B, illustrating another modified example of a work vehicle equipped with a lighting device. [Figure 11] Figure 11 is a diagram corresponding to Figure 2B, illustrating yet another modified example of a work vehicle equipped with a lighting device. [Figure 12] Figure 12 is a diagram corresponding to Figure 2B, illustrating yet another modified example of a work vehicle equipped with a lighting device. [Figure 13] Figure 13 is a diagram corresponding to Figure 2A, illustrating yet another modified example of a work vehicle equipped with a lighting device. [Figure 14] Figure 14 is a diagram corresponding to Figure 2B, and shows the work vehicle with lighting equipment shown in Figure 13. [Figure 15] Figure 15 is a perspective view showing an example of a lighting device. [Figure 16] Figure 16 is a perspective view showing another example of a lighting device. [Figure 17] Figure 17 is a cross-sectional view showing yet another example of a lighting device. [Figure 18] Figure 18 is a perspective view showing yet another example of a lighting device. [Figure 19] Figure 19 is a side view showing yet another example of a lighting device. [Figure 20] Figure 20 illustrates yet another example of a lighting device. [Figure 21A] Figure 21A is a perspective view showing an example of an observation support device. [Figure 21B] Figure 21B is a perspective view showing an observer wearing the observation support device shown in Figure 21A. [Figure 21C] Figure 21C is a perspective view showing a modified example of the observation aid device shown in Figure 21A. [Figure 22A] Figure 22A is a perspective view showing another example of an observation aid. [Figure 22B] Figure 22B is a perspective view showing an observer wearing the observation support device shown in Figure 22A. [Figure 23] Figure 23 is a side view showing yet another example of an observation support device, along with the observer. [Figure 24] Figure 24 is a side cross-sectional view showing yet another example of an observation aid. [Figure 25] Figure 25 is a side view showing other examples of work assistance systems and observation assistance devices. [Figure 26A] Figure 26A is a graph showing an example of the transmission spectrum of an optical filter that may be included in a work assistance system and observation assistance device. [Figure 26B] Figure 26B is a cross-sectional view showing an example of the layer configuration of an optical filter that may be included in a work assistance system and observation assistance device. [Modes for carrying out the invention]

[0047] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that, for the sake of illustration and ease of understanding, the scale and aspect ratios of the drawings attached to this specification have been appropriately altered and exaggerated from those of the actual objects.

[0048] To clarify directional relationships between drawings, some drawings use arrows to indicate the first direction D1, the second direction D2, and the third direction D3 as common directions across the drawings. The tip of the arrow corresponds to one side of each direction D1, D2, and D3. Additionally, arrows pointing towards the back of the drawing, perpendicular to the plane of the drawing, are indicated by a symbol of an "x" inside a circle, as shown in Figure 2A. Arrows pointing towards the front of the drawing, perpendicular to the plane of the drawing, are indicated by a symbol of a dot inside a circle, as shown in Figure 2B.

[0049] In this specification, terms such as "parallel," "perpendicular," and "identical," as well as values ​​of length and angle, which specify shapes, geometric conditions, and their degrees, should not be interpreted in a strict sense, but rather to include a range that can be expected to function similarly.

[0050] In this embodiment, the work vehicle 10 with a lighting device has a work vehicle 20. The work vehicle 20 can perform specific tasks while moving. In other words, the operator uses the work vehicle 10 with a lighting device with the intention of performing specific tasks using the work vehicle 20 while the work vehicle 20 is moving. In the embodiment described below, a mechanism has been put in place to facilitate the linear movement of the work vehicle 20 toward the target point 98. Specifically, the work vehicle 10 with a lighting device has a lighting device 30, and the lighting of the lighting device 30 guides the movement of the work vehicle 20. This makes it possible to easily and stably perform the desired task using the work vehicle 20.

[0051] In the following, one embodiment will be described with reference to a specific example shown in the drawings.

[0052] The work vehicle 20 performs or assists in specific tasks. The work vehicle 20 can move on a moving surface 95. Work can be performed while the work vehicle 20 is moving on the moving surface 95. The moving surface 95 is not particularly limited. Examples of the moving surface 95 include roads, sidewalks, parking lots, warehouse floors, fields, meadows, etc. The work vehicle 20 may have wheels 22. The work vehicle 20 may have crawlers, caterpillars, etc., instead of or in addition to the wheels 22. The work vehicle 20 may have a drive unit 23. The work vehicle 20 may be moved by being pushed or pulled by an operator. The work vehicle 20 may have a movement assist device. The movement assist device outputs an assisting force when the work vehicle 20 is moved by being pushed or pulled by an operator, thereby assisting the movement of the work vehicle 20. The work vehicle 20 can move along a straight line, and may also be able to move along curves and bends. The direction of movement of the work vehicle 20 may be adjusted by operation by an operator riding in or pushing the work vehicle 20, or by remote operation by the operator.

[0053] Examples of work vehicles 20 include work vehicles for constructing roads and sidewalks, work vehicles for maintaining roads and sidewalks, work vehicles for agricultural work, and work vehicles for maintaining fields. Examples of work vehicles for constructing roads and maintaining roads include graders, asphalt finishers, road rollers, tire rollers, wheel loaders, mixer trucks, line marking vehicles, snowplows, and sweeping vehicles. Examples of work vehicles for agricultural work and maintaining fields include rice transplanters, harvesters, lawnmowers, tractors, pesticide sprayers, and tillers. In addition, special vehicles and industrial vehicles specified in ISO 5053-1 may also be considered work vehicles 20.

[0054] The work vehicle 20 shown in Figure 1 comprises a body 21, wheels 22 rotatably held on the body 21, and a handle 24 attached to the body 21. The work vehicle 20 also has a drive unit 23 and a work device 25 supported on the body 21. The illustrated work vehicle 20 moves or is assisted in moving by rotating the wheels 22 with the driving force from the drive unit 23. The direction of the work vehicle 20 can be adjusted by the operator applying force through the handle 24. That is, the direction of movement of the work vehicle 20 is adjusted by the force applied by the operator to the handle 24.

[0055] In the specific example shown in Figure 1, the work vehicle 20 is a line-drawing vehicle that supplies ink, lime powder, etc., to a moving surface 95. The illustrated work vehicle 20 can be used to draw white or orange lines on roads, sidewalks, and parking lots. The illustrated work vehicle 20 can also be used to draw lines of various colors on the floors of gymnasiums and auditoriums. The work device 25 has a colorant holding section 26 that contains colorants, and a supply section 27 that supplies the colorants from the colorant holding section 26 to the moving surface 95. The supply section 27 is a tubular member. The supply section 27 has a supply port 27a that opens downwards. The supply port 27a faces the moving surface 95 on which the work vehicle 20 is positioned. As the work vehicle 20 moves, the work device 25 supplies colorants to the moving surface 95. This makes it possible to draw lines 97 on the moving surface 95 while moving the work vehicle 20.

[0056] The lighting device 30 is attached to the work vehicle 20. The lighting device 30 irradiates coherent light onto the area to be illuminated 90 on the moving surface 95. In other words, the lighting device 30 projects a pattern of the area to be illuminated 90 onto the moving surface 95. In the illustrated example, the moving surface 95, which is the projection surface, is formed by the road surface. As shown in Figures 2A and 2B, when the relative positional relationship between the lighting device 30 and the moving surface 95 is constant, coherent light is initially directed onto the area to be illuminated 90 on the moving surface 95 that is in a predetermined positional relationship with the work vehicle 10 equipped with the lighting device. For example, if the moving surface 95 is a flat surface, a pattern of the shape of the area to be illuminated 90 is projected onto the range of the moving surface 95 that is in a predetermined positional relationship with the work vehicle 10 equipped with the lighting device. Then, as the work vehicle 10 equipped with the lighting device moves on the moving surface 95, the area to be illuminated 90 also moves on the moving surface 95.

[0057] The lighting device 30 mounted on the work vehicle 20 may, for example, emit coherent light to illuminate the area to be illuminated 90 on the moving surface 95 when the main power of the work vehicle 20 is turned on. As another example, the lighting device 30 may emit coherent light to illuminate the area to be illuminated 90 on the moving surface 95 while the work vehicle 20 is moving. As yet another example, the lighting device 30 mounted on the work vehicle 20 may emit coherent light to illuminate the area to be illuminated 90 on the moving surface 95 in response to instructions from the operator.

[0058] As shown in Figures 2A and 2B, the illuminated area 90 includes the area in front of the work vehicle 20 in the direction of movement. The illuminated area 90 is located at least in front of the work vehicle 20 in its current direction of movement. When the work vehicle 20 begins to turn, the illuminated area 90 is located in front of the work vehicle 20 in the direction of movement at any given moment. In the example shown in Figures 2A and 2B, the illuminated area 90 is located only in front of the work vehicle 20 in the direction of movement.

[0059] The illuminated area 90 may show information related to the current direction of movement of the work vehicle 20. The illuminated area 90 may extend along the direction of movement. In the illustrated example, the work vehicle 20 is moving in a first direction D1 on the moving surface 95. In the illustrated example, the illuminated area 90 is along a straight line extending in the first direction D1, which is the current direction of movement of the work vehicle 20. In this example, the first direction D1 is the direction of movement of the work vehicle 20. The second direction D2 is perpendicular to the first direction D1 and along the moving surface 95. The third direction D3 is perpendicular to the moving surface 95 and is perpendicular to both the first direction D1 and the second direction D2.

[0060] In the illustrated example, the illuminated area 90 faces the work vehicle 20 in the first direction D1, which is the current direction of movement of the work vehicle 20. The illuminated area 90 extends in a long, narrow shape along the first direction D1. The first direction D1, which is the current direction of movement of the work vehicle 20, is the longitudinal direction of the illuminated area 90.

[0061] The illuminated area 90 indicates the path of the work vehicle 20 when it moves in a straight line while maintaining its current direction of movement. Therefore, when the work vehicle 20 is moving while performing work, the operator can adjust the orientation of the work vehicle 20 based on the illuminated area 90. For example, when performing work in a straight line to a target point 98 located far away from the work vehicle 20, the illuminated area 90 is useful. In this situation, the operator adjusts the orientation of the work vehicle 20 so that the illuminated area 90 is positioned over the target point 98, as shown in Figure 2B. Alternatively, the operator adjusts the orientation of the work vehicle 20 so that the target point 98 is located on the extension of the illuminated area 90 that extends along a straight line. The operator then moves the work vehicle 20 while maintaining the alignment of the illuminated area 90 with respect to the target point 98. When adjusting the direction of movement of the work vehicle 20 in this way, the operator can easily and accurately control the work vehicle 20 while observing the distant target point 98.

[0062] As a result, meandering of the work vehicle 20's movement path can be suppressed, allowing the work vehicle 20 to move in a straight line towards the target point 98. Therefore, the work path carried out using the work vehicle 20 will also be straight with suppressed meandering. This allows work to be carried out stably in a straight line towards the target point 98, even if the target point 98 is far away. Since the direction of movement of the work vehicle 20 can be easily adjusted, the movement speed of the work vehicle 20 can be increased. This improves not only work accuracy but also work efficiency.

[0063] Especially when performing work outdoors at night, it is difficult to move the work vehicle 20 in a straight line towards a target point 98 that is more than 20m away. In contrast, the work vehicle 10 with a lighting device of this embodiment uses the lighting device 30 to guide the work vehicle 20. Therefore, the work vehicle 10 with a lighting device is suitable for use in dark environments. For example, road maintenance may be carried out at night. This embodiment, which utilizes lighting, is suitable for such nighttime work. By enabling stable and efficient nighttime work, the number of working days can be reduced.

[0064] In the illustrated work vehicle 10 equipped with a lighting device, a straight line can be drawn on the road, which serves as the moving surface 95, using the work device 25. Moreover, the line can be drawn in a short time. Therefore, the number of working days can be reduced, and the impact on traffic can be minimized.

[0065] In the examples shown in Figures 1 to 2B, the illuminated area 90 is located only in front of the work vehicle 20 in the first direction D1, which is the direction of movement. Not limited to this example, the illuminated area 90 may include at least part of the area where the work vehicle 20 is located in the first direction D1, which is the direction of movement, as shown in Figure 3. The illuminated area 90 may include at least one of the area where the front end of the work vehicle 20 is located in the first direction D1, which is the direction of movement, and the area where the rear end of the work vehicle 20 is located in the first direction D1, which is the direction of movement. In the example shown in Figure 3, the illuminated area 90 includes the entire area where the work vehicle 20 is located in the first direction D1, which is the direction of movement. According to this example, depending on the configuration of the work vehicle 20, the orientation and position of the work vehicle 20 can be easily and accurately adjusted with respect to the area to be worked on.

[0066] As shown in Figure 3, the illuminated area 90 may include the area located behind the work vehicle 20 in the first direction D1, which is the direction of movement. In this example, depending on the configuration of the work vehicle 20, the orientation and position of the work vehicle 20 can be easily and accurately adjusted with respect to the area to be worked on.

[0067] Furthermore, as shown in Figure 3, the illuminated area 90 may include at least a portion of the area WA where work is being performed by the work vehicle 20. In the illustrated example, the illuminated area 90 includes the area on the moving surface 95 facing the supply port 27a of the work device 25, i.e., the area to which the colorant is applied. In this example, the orientation and position of the work vehicle 20 can be easily and accurately adjusted with respect to the area to be worked on. In addition, it is easy to confirm whether work using the work vehicle 20 is actually being performed in the area to be worked on. In the illustrated example, it is easy and accurate to determine whether the colorant has been applied to the area to which it should be applied.

[0068] In the example shown in Figure 3, the lighting device 30 is installed on the side of the work vehicle 20. The illuminated area 90 is located on the side of the work vehicle 20 and extends in the first direction D1, which is the direction of movement of the work vehicle 20.

[0069] As shown in Figures 4A to 4D, a target 80 may be used in combination with the lighting device 30. The target 80, together with the lighting device 30, constitutes the work support device 5. The target 80 is used to make it easier to observe the target point 98. As shown in Figures 4A to 4D, the target 80 may be placed on the target point 98. This makes it easier for the operator to observe the target point 98 through the target 80. The operator can then align the illuminated area 90 with respect to the target point 98 by positioning the illuminated area 90 relative to the target 80.

[0070] In the example shown in Figure 4A, the target 80 is made of a resin cone. In the example shown in Figure 4B, the target 80 has a rectangular parallelepiped shape. This target 80 has a display unit 81. The operator can align the illuminated area 90 with the target 80 while observing the display unit 81. The display unit 81 may also emit light. In the example shown in Figure 4C, the target 80 has a light-emitting unit 82 extending in a third direction D3 perpendicular to the moving surface 95. As shown in Figure 4D, the target 80 may have a reflector unit 83. The reflector unit 83 may diffusely reflect coherent light from the lighting device 30. The reflector unit 83 may retroreflect coherent light from the lighting device 30. In the example shown in Figure 4D, coherent light is incident on only a portion of the reflector unit 83. In nighttime work, the presence of a light-emitting unit 82 in the target 80 makes it significantly easier to adjust the direction of movement of the work vehicle 10 with the lighting device. Furthermore, the reflective portion 83 of the target 80 reflects coherent light from the lighting device 30, which significantly simplifies the adjustment of the direction of movement of the work vehicle 10 equipped with the lighting device during nighttime work.

[0071] The target 80 may be portable. That is, the target 80 may be able to be carried by the operator without the use of special means. For example, it may be kept on the work vehicle 20. When the work location using the work vehicle 20 changes, the target 80 may be placed on the next target location 98.

[0072] As shown in Figure 4D, the width of the target 80 along the second direction D2 may be smaller than the width of the illuminated area 90 along the second direction D2. In this example, as shown in Figure 4D, the illuminated area 90 extends behind the target 80. Therefore, the illuminated area 90 can be easily positioned relative to the target 80 and the target point 98. For similar reasons, the target 80 may be transparent or have holes to the extent that the illuminated area 90 extends behind it.

[0073] The target 80 is not limited to the illustrated example. The target 80 is not limited to a member that protrudes or bulges from the moving surface 95 in a third direction D3. The target 80 may be, for example, a marker or line provided on the moving surface 95. In the illustrated example of the line-drawing vehicle, a line drawn in a previous operation, i.e., a faded line, can become the target 80. Alternatively, plants such as trees or objects installed on the moving surface 95 may also be used as the target 80.

[0074] The length L of the illuminated area 90 along the direction of movement on the moving surface 95 may be 3m or more, 5m or more, 20m or more, or even 50m or more. As shown in Figure 2B, length L is the length (m) of the illuminated area 90 along the first direction D1. It is not easy to move the work vehicle 20 in a straight line while observing a target point 98 that is 20m or more away without illuminating the illuminated area 90. Therefore, it is effective to set such a lower limit for the length L (m) of the illuminated area 90. By setting the illuminated area 90 to 3m or more, the illuminated area 90 can serve as an effective guide when aiming for a target point 98 that is 20m or more away. The length L (m) of the illuminated area 90 may be 100m or less in combination with the lower limit described above.

[0075] The width W of the illuminated area 90 along the direction perpendicular to the direction of movement of the work vehicle 20 on the moving surface 95 may be 0.002m or more and 0.2m or less, 0.01m or more and 0.2m or less, 0.02m or more and 0.1m or less, or 0.03m or more and 0.05m or less. As shown in Figure 2B, the width W is the length (m) of the illuminated area 90 along the second direction D2. With the illuminated area 90 having an upper limit set on the width W in this way, the direction of movement of the work vehicle 20 can be indicated more clearly. Furthermore, the work vehicle 20 can be moved stably in the first direction D1. By setting a lower limit on the width W of the illuminated area 90, a long illuminated area 90 can be sufficiently observed. Furthermore, by setting an upper limit on the width W of the illuminated area 90, the work accuracy in the second direction D2 can be improved, for example, if the work involves forming a straight line, the degree of straightness can be improved. In addition, because the light beam emitted from the lighting device 30 is concentrated in the illuminated area 90 with a limited width W, the brightness of the illuminated area 90 for the operator can also be improved.

[0076] The ratio (L / W) of the length L (m) of the illuminated area 90 along the direction of movement on the moving surface 95 to the width W (m) of the illuminated area 90 along the direction perpendicular to the direction of movement on the moving surface 95 may be 25 or more and 10000 or less, 50 or more and 100 or more and 500 or less. By setting a lower limit on the ratio of length L to width W in this way, the direction of movement of the work vehicle 20 can be indicated more clearly. Furthermore, the work vehicle 20 can be moved stably in the first direction D1.

[0077] As will be described in detail later with reference to Figure 15, etc., the illumination device 30 includes a light source 40 that emits coherent light and a diffractive optical element 50 that diffracts the coherent light from the light source 40. The illumination device 30 illuminates the area to be illuminated 90 with the coherent light diffracted by the diffractive optical element 50. With such an illumination device 30, it is possible to illuminate a large area of ​​the area to be illuminated 90 on the moving surface 95, or an area to be illuminated 90 that extends far away from the illumination device 30. That is, with an illumination device 30 using a coherent light source 40 and a diffractive optical element 50, it is possible to achieve the above-mentioned values ​​for length L(m), width W(m), and the ratio of length L(m) to width W(m) for the area to be illuminated 90.

[0078] Incidentally, as a means of guiding the movement of the work vehicle 20, it is conceivable to extend a rod-shaped member forward in the direction of movement from the work vehicle. However, as the work vehicle moves, there is a possibility that the rod-shaped member may come into contact with some object. For example, the rod-shaped member may come into contact with trees, etc. Furthermore, there is a possibility that pedestrians or vehicles around the work vehicle 20 may come into contact with it. In this regard, in this embodiment, coherent light is irradiated from the lighting device 30 toward the moving surface 95. Even if an object or the like were to enter between the lighting device 30 and the illuminated area 90 of the moving surface 95, physical contact can be avoided. Furthermore, due to physical constraints, it is practically impossible to make the length of the rod-shaped member 10m or more.

[0079] The shape of the illuminated area 90 is not limited to the example shown in Figure 2B. The illuminated area 90 may adopt a shape or pattern that extends along a straight line. The illuminated areas 90 shown in Figures 5A and 5B, like the illuminated area 90 shown in Figure 2B, are along a straight line that extends parallel to the direction of movement of the work vehicle 20 at that moment. The illuminated area 90 shown in Figure 5A has a dotted line shape along a straight line that extends parallel to the direction of movement of the work vehicle 20 at that moment. In other words, the illuminated area 90 shown in Figure 5A has multiple elemental areas 90a arranged along a straight line that extends parallel to the direction of movement of the work vehicle 20 at that moment. The illuminated area 90 shown in Figure 5B also has multiple elemental areas 90a arranged along a straight line that extends parallel to the direction of movement of the work vehicle 20 at that moment. In the example shown in Figure 5A, each elemental area 90a may be linear, rectangular, or dotted. In the example shown in Figure 5B, each element region 90a is an arrow. Each arrow points away from the lighting device 30. These examples allow for the indication that the work vehicle 20 is moving around the work vehicle 10 equipped with lighting devices.

[0080] In the examples shown in Figures 2B to 5B, the illuminated area 90 includes a linear or dotted first area 91 extending along the direction of movement of the work vehicle 20. As shown in Figures 6 and 7, the illuminated area 90 may also include a second area 92 extending in a direction not parallel to the direction of movement of the work vehicle 20, in addition to the first area 91. These configurations make the first area 91 of the illuminated area 90 more conspicuous. Furthermore, the operator of the work vehicle 10 with the lighting device can determine the distance from the work vehicle 20 by the second area 92. In addition, it is possible to inform those around the work vehicle 10 with the lighting device that the work vehicle 20 is moving.

[0081] The second region 92 may extend on the moving surface 95 in a direction inclined at a greater than 45° with respect to the first direction D1, which is the direction of movement. With this configuration, the second region 92 becomes more conspicuous. This makes the effect of providing the second region 92 more pronounced.

[0082] As shown in Figures 6 and 7, the second region 92 may extend from the first region 91. As shown by solid lines in Figures 6 and 7, the second region 92 may extend from the first region 91 to either side in the second direction D2. As shown by solid and dashed lines in Figures 6 and 7, the second region 92 may extend from the first region 91 to both sides in the second direction D2.

[0083] The second region 92 may extend from the end of the first region 91. This configuration makes the end of the first region 91 more visible. Furthermore, the illuminated region 90 may include multiple second regions 92 together with the first region 91. The multiple second regions 92 are positioned at intervals in the first direction D1. The spacing of the second regions 92 in the first direction D1 may be constant. The spacing of the second regions 92 in the first direction D1 may be set to a predetermined length. With the illuminated region 90 having these configurations, the operator of the work vehicle 10 with the lighting device can determine the distance from the work vehicle 20 to each position on the moving surface 95 by using the second regions 92.

[0084] When the relative positional relationship between the lighting device 30 and the moving surface 95 is constant, coherent light is irradiated onto the illuminated area 90 on the moving surface 95 that is in a predetermined positional relationship with the work vehicle 10 equipped with the lighting device. Therefore, by adjusting the mounting position of the lighting device 30 on the work vehicle 20, coherent light can be irradiated onto the illuminated area 90 that is in a predetermined positional relationship with the work vehicle 10 equipped with the lighting device. In other words, by adjusting the mounting position of the lighting device 30 on the work vehicle 20, the position of the illuminated area 90 on the moving surface 95 can be adjusted. In specific applications, the shape of the illuminated area 90 on the moving surface 95 may be changed by adjusting the mounting position of the lighting device 30 on the work vehicle 20.

[0085] The illumination device 30 may be mounted on the work vehicle 20 so as to be adjustable in the vertical direction. That is, the direction of emission of coherent light from the illumination device 30 may change in the third direction D3. In the example shown in Figure 8, the direction of emission of coherent light from the illumination device 30 changes when observed from the second direction D2 parallel to the moving surface 95. For example, the position of the illuminated area 90 on the moving surface 95 may be changed by rotating the illumination device 30 about an axis parallel to the second direction D2. In Figure 8, the direction of emission of coherent light from the illumination device 30 is tilted so as to face the moving surface 95 in the third direction D3. As a result, as shown in Figure 9, the illuminated area 90 on the moving surface 95 approaches the work vehicle 10 with the illumination device along the first direction D1. Furthermore, because the optical path from the lighting device 30 to the illuminated area 90 is shortened, the length of the illuminated area 90 along the first direction D1 is shortened, and the width of the illuminated area 90 along the second direction D2 is shortened.

[0086] Unlike the examples shown in Figures 8 and 9, the orientation of the lighting device 30 in the vertical direction relative to the work vehicle 20 may be adjusted so that the direction of emission of coherent light from the lighting device 30 moves away from the moving surface 95 in the third direction D3. With this adjustment, the illuminated area 90 on the moving surface 95 moves away from the work vehicle 10 with the lighting device along the first direction D1. In addition, since the optical path from the lighting device 30 to the illuminated area 90 becomes longer, the length of the illuminated area 90 along the first direction D1 becomes longer, and the width of the illuminated area 90 along the second direction D2 becomes longer.

[0087] The illumination device 30 may be mounted on the work vehicle 20 so as to be adjustable in the left-right direction. That is, the direction of emission of coherent light from the illumination device 30 may change in the second direction D2. In the example shown in Figure 10, the direction of emission of coherent light from the illumination device 30 changes when observed from the third direction D3, which is the normal direction ND to the moving surface 95. For example, the position of the illuminated area 90 on the moving surface 95 may be changed by rotating the illumination device 30 about an axis parallel to the third direction D3. In the example shown in Figure 10, the illuminated area 90 moves on the moving surface 95 along an arc centered on the rotation axis of the illumination device 30.

[0088] Furthermore, the lighting device 30 may be mounted on the work vehicle 20 so as to be able to adjust its rotational position around an axis that is not parallel to both the left-right and up-down directions. For example, the position of the illuminated area 90 on the moving surface 95 may be changed by rotating the lighting device 30 around an axis parallel to the first direction D1. The example shown in Figure 11 shows the movement of the illuminated area 90 on the moving surface 95 when the lighting device 30 is rotated around an axis parallel to the first direction D1. According to the example shown in Figure 11, the illuminated area 90 moves in the second direction D2 on the moving surface 95. The amount of movement of each part of the illuminated area 90 in the second direction D2 changes depending on the distance from the lighting device 30 to that part of the illuminated area 90. As the distance from the lighting device 30 to a part of the illuminated area 90 increases, the amount of movement of each part of the illuminated area 90 in the second direction D2 increases. Furthermore, the width W in the second direction D2 for each part of the illuminated area 90 changes depending on the distance from the lighting device 30 to that part of the illuminated area 90. As the distance from the lighting device 30 to a part of the illuminated area 90 increases, the width W of each part of the illuminated area 90 increases.

[0089] Furthermore, the lighting device 30 may be mounted on the work vehicle 20 so as to be adjustable in at least one of the left-right and up-down directions. In the example shown in Figure 12, the mounting position of the lighting device 30 on the work vehicle 20 is moved in the second direction D2. As the mounting position of the lighting device 30 on the work vehicle 20 shown in Figure 12 moves, the position of the illuminated area 90 on the moving surface 95 also moves in the second direction D2. When the mounting position of the lighting device 30 moves to the left in the left-right direction, the illuminated area 90 on the moving surface 95 also moves to the left in the left-right direction. When the mounting position of the lighting device 30 moves to the right in the left-right direction, the illuminated area 90 on the moving surface 95 also moves to the right in the left-right direction.

[0090] In the example shown in Figure 13, the mounting position of the lighting device 30 on the work vehicle 20 is moved in the third direction D3. As the mounting position of the lighting device 30 on the work vehicle 20 moves in the third direction D3 as shown in Figure 13, the position of the illuminated area 90 on the moving surface 95 moves in the first direction D1. When the lighting device 30 approaches the moving surface 95 in the third direction D3, the illuminated area 90 approaches the work vehicle 10 with the lighting device along the first direction D1 on the moving surface 95. Also, as shown in Figure 14, since the optical path from the lighting device 30 to the illuminated area 90 becomes shorter, the length of the illuminated area 90 along the first direction D1 becomes shorter, and the width of the illuminated area 90 along the second direction D2 becomes shorter.

[0091] Unlike the examples shown in Figures 13 and 14, when the lighting device 30 moves away from the moving surface 95 in the third direction D3, the illuminated area 90 moves away from the work vehicle 10 with the lighting device along the first direction D1 on the moving surface 95. Also, because the optical path from the lighting device 30 to the illuminated area 90 becomes longer, the width of the illuminated area 90 along the second direction D2 becomes longer.

[0092] The lighting device 30 may be attached to the lighting device 30 via an elastically deformable cushioning material. The cushioning material absorbs vibrations and shocks transmitted from the work vehicle 20 to the lighting device 30 while the work vehicle 20 is in motion. Rubber or resin may be used as the cushioning material. The cushioning material prevents the illuminated area 90 from moving on the moving surface 95 while the work vehicle 10 with the lighting device is in motion. This makes it easier to operate the work vehicle 20 in the direction of movement and allows work to be carried out stably.

[0093] When attaching the lighting device 30 to the lighting device 30 using fasteners such as screws and bolts, spring washers may be used. Spring washers absorb vibrations and shocks transmitted from the work vehicle 20 to the lighting device 30 while the work vehicle 20 is in motion. This helps to prevent the fasteners from loosening. Adhesive may also be used when attaching the lighting device 30 to the lighting device 30. By using adhesive, or by using adhesive in combination with other fasteners, the lighting device 30 can be attached more stably. For example, when attaching the lighting device 30 to the lighting device 30 using fasteners such as screws and bolts, adhesive may also be used.

[0094] Next, the specific configuration of the lighting device 30 will be described.

[0095] As shown in Figure 15, the illumination device 30 may include a light source 40, a shaping optical system 45, and a diffractive optical element 50. The light source 40 is a component that emits coherent light and is not particularly limited. The light source 40 emits coherent light with a constant wavelength and phase. The coherent light emitted from the light source 40 has excellent directivity. Therefore, the light source 40 is suitable for an illumination device 30 that illuminates distant areas. Various types of light sources can be used as the light source 40. A laser light source that emits laser light may be used as the light source 40. A semiconductor laser light source can be exemplified as a laser light source. In the example shown in Figure 15, the light source 40 includes a single coherent light source. Therefore, in the example shown in Figure 15, the illuminated area 90 is illuminated with coherent light of a color corresponding to the wavelength range of the coherent light emitted from the light source 40.

[0096] The shaping optical system 45 shapes the light emitted from the light source 40. For example, the shaping optical system 45 shapes the shape of the coherent light in a cross section perpendicular to the optical axis, or the three-dimensional shape of the coherent light. The shaping optical system 45 may also enlarge the cross-sectional area of ​​the coherent light in a cross section perpendicular to the optical axis.

[0097] In the example shown in Figure 15, the shaping optical system 45 shapes the light emitted from the light source 40 into a widened parallel beam. That is, the shaping optical system 45 functions as a collimating optical system. In the example shown in Figure 15, the shaping optical system 45 has a first lens 46 and a second lens 47 arranged along the optical path. The first lens 46 shapes the light emitted from the light source 40 into a divergent beam. The second lens 47 shapes the divergent beam generated by the first lens 46 into a parallel beam. In this example, the second lens 47 functions as a collimating lens.

[0098] The diffractive optical element 50 changes the direction of propagation of coherent light from the light source 40. The coherent light diffracted by the diffractive optical element 50 illuminates the illuminated area 90 on the moving surface 95. The diffractive optical element 50 diffracts the coherent light from the light source 40 and directs it towards the illuminated area 90 on the moving surface 95. As a result, the diffracted light from the diffractive optical element 50 is projected onto the moving surface 95. The moving surface 95 is illuminated in a pattern corresponding to the diffraction pattern of the illuminated area 90 by the diffractive optical element 50.

[0099] The diffractive optical element 50 may be a holographic element. By using a holographic element as the diffractive optical element 50, it becomes easier to design the diffraction characteristics of the diffractive optical element 50. A holographic element that can project light only to the entire area of ​​a desired region having a predetermined position, contour shape, size, and orientation on the moving surface 95 can be designed relatively easily. The region on the moving surface 95 that is irradiated with coherent light becomes the illuminated region 90.

[0100] When designing the diffractive optical element 50, the illuminated area 90 is set in real space at a predetermined position relative to the diffractive optical element 50, with a predetermined contour shape, size, and orientation. The position, contour shape, size, and orientation of the illuminated area 90 on the moving surface 95 depend on the diffraction characteristics of the diffractive optical element 50. By adjusting the diffraction characteristics of the diffractive optical element 50, the position, contour shape, size, and orientation of the illuminated area 90 on the moving surface 95 can be arbitrarily adjusted. Therefore, when designing the diffractive optical element 50, first the position, contour shape, size, and orientation of the illuminated area 90 on the moving surface 95 are determined. Next, the diffraction characteristics of the diffractive optical element 50 should be adjusted so that light can be projected over the entire determined illuminated area 90.

[0101] The diffractive optical element 50 can be fabricated as a computer-generated hologram (CGH). A computer-generated hologram is fabricated by calculating a structure with arbitrary diffraction characteristics on a computer. Therefore, by using a computer-generated hologram as the diffractive optical element 50, it is possible to eliminate the need to generate object light and reference light using a light source and optical system, and to record interference fringes on the hologram recording material by exposure. The illumination device 30 is intended to irradiate a to-illuminate area 90 with a predetermined contour shape, size, and orientation at a predetermined position relative to the illumination device 30 with coherent light. By inputting information about the to-illuminate area 90 as parameters into the computer, a structure with diffraction characteristics capable of projecting diffractive light onto the to-illuminate area 90, such as an uneven surface, can be identified by computer calculations. By forming the identified structure, for example, by resin molding, the diffractive optical element 50 as a computer-generated hologram can be fabricated in a simple procedure at low cost.

[0102] For the design of the diffractive optical element 50, for example, the iterative Fourier transform method may be used. When the iterative Fourier transform method is used, the processing is performed assuming that the illuminated region 90 is far from the diffractive optical element 50, and the pattern projected onto the moving surface 95 may be taken as the Fraunhofer diffraction pattern. Therefore, the moving surface 95 may be non-parallel to the diffraction plane of the diffractive optical element 50.

[0103] As shown in Figure 16, the diffractive optical element 50 may include a plurality of elemental diffractive optical elements 55. Each elemental diffractive optical element 55 is, for example, a hologram element and can be configured in the same way as the diffractive optical element 50 described above. In the example shown in Figure 16, the coherent light diffracted by the plurality of elemental diffractive optical elements 55 is directed to the same illuminated region 90. That is, the light diffracted by each elemental diffractive optical element 55 is directed to the entire illuminated region 90 on the moving surface 95. With such a diffractive optical element 50, light directed towards each position in the illuminated region 90 can be emitted in a dispersed manner from the plurality of elemental diffractive optical elements 55 included in the diffractive optical element 50. This suppresses excessive brightness at each position on the diffractive optical element 50 and improves laser safety.

[0104] Each elemental diffractive optical element 55 may be configured to have the same diffraction characteristics as the others. However, in order to achieve higher precision projection, each elemental diffractive optical element 55 may be given separately designed diffraction characteristics depending on its position within the diffractive optical element 50. In this example, by adjusting the diffraction characteristics of each elemental diffractive optical element 55 according to the difference in its position relative to the other elemental diffractive optical elements 55, the diffractive light can be directed with high precision only to the entire illuminated area 90 on the moving surface 95.

[0105] Incidentally, with an illumination device 30 having a light source 40 that emits coherent light and a diffractive optical element 50 that diffracts coherent light, it is possible to illuminate a large area of ​​the illuminated region 90 on the moving surface 95, or an illuminated region 90 that extends far from the illumination device 30. In this case, the angle of incidence α of the coherent light to each position within the illuminated region 90 varies greatly. As shown in Figure 2A, the angle of incidence α to the illuminated region 90 far from the illumination device 30 becomes very large, for example, close to 90°. The diffraction plane of the diffractive optical element 50 comes to form a large angle with respect to the moving surface 95 and the illuminated region 90. Here, the angle of incidence α to the illuminated region 90 is the angle that the direction of propagation of the coherent light makes with respect to the normal direction ND of the illuminated region 90. In the illustrated example, the normal direction ND is parallel to the third direction D3, which is orthogonal to both the first direction D1 and the second direction D2.

[0106] In this illumination device 30, the diffractive optical element 50 adjusts the optical path of the coherent light. The optical path adjustment function of the diffractive optical element 50 is highly accurate. Therefore, the optical path of the coherent light can be adjusted by the diffractive optical element 50 toward the illumination area 90 of a desired shape. As a result, the illumination area 90 can be set even at positions far away from the illumination device 30, or at positions where the incident angle α of the coherent light becomes large, without being strongly constrained by the relative position to the illumination device 30. In other words, the degree of freedom in setting the illumination area 90 and the movable surface 95 can be greatly improved. As a result, coherent light can be irradiated onto the illumination area 90 with high accuracy.

[0107] For example, a diffractive optical element 50 made of a computer-generated hologram can adjust the direction of propagation of coherent light incident from a certain direction with an accuracy of ±0.01° in angular space. By using such a diffractive optical element 50, it is possible to illuminate areas 90 located at a distance of 1m to 120m from the diffractive optical element 50, or areas 90 where the incident angle α of coherent light onto the illuminated area 90 is at least 30° and at most 89.99°, with high precision. Therefore, the lighting device 30 mounted on the work vehicle 20 can project coherent light with high precision onto areas 90 located on the moving surface 95. This makes the edges of the illuminated areas 90 clear, and the operator can observe illuminated areas 90 located at a distance.

[0108] Furthermore, by using the diffractive optical element 50, it becomes possible to easily adjust the distribution of luminous intensity from the output end 31 of the illumination device 30 toward each position within the illuminated area 90. For example, the luminous intensity directed from the output end 31 of the illumination device 30 toward one position in the illuminated area 90 can be made greater than the luminous intensity from the output end 31 of the illumination device 30 toward another position in the illuminated area 90 toward which the distance to the output end 31 is shorter than the distance from that position to the output end (output surface) 31. In other words, the luminous intensity directed toward a position far from the output end 31 can be set higher. Moreover, the luminous intensity directed from the output end 31 of the illumination device 30 toward any position in the illuminated area 90 may be set to be greater than or equal to the luminous intensity from the output end 31 of the illumination device 30 toward another position in the illuminated area 90 toward which the distance to the output end 31 is shorter than the distance from that arbitrary position to the output end 31. In other words, the luminous intensity may be made to gradually increase as the position moves further away from the output end 31. These luminosity adjustments make it possible to illuminate the illuminated area 90 with a generally uniform brightness for observation by an operator riding in a work vehicle. In particular, it is effective in illuminating the elongated illuminated area 90, which extends away from the emission end 31 of the illumination device 30, with a uniform brightness. Luminous intensity is the amount of energy emitted from the illumination device 30 within a unit solid angle (within a small angular range), and its unit is [cd]. In the illustrated example, the emission end 31 of the illumination device 30 is formed by a diffractive optical element 50.

[0109] Figure 17 shows a specific configuration example of the lighting device 30. The lighting device 30 shown in Figure 17 is portable. That is, the lighting device 30 shown in Figure 17 can be carried by an operator without the use of special means. The lighting device 30 has a casing 70. In the lighting device 30 shown in Figure 17, the light source 40, the shaping optical system 45, and the diffractive optical element 50 are fixed to the casing 70. In normal use, the light source 40, the shaping optical system 45, and the diffractive optical element 50 are not intended to be removed from the casing 70. The light source 40, the shaping optical system 45, and the diffractive optical element 50 are not removable from the casing 70. This maintains the relative positions of the light source 40, the shaping optical system 45, and the diffractive optical element 50. This allows for highly accurate and stable illumination of the area to be illuminated 90 on the moving surface 95, which is in a predetermined relative positional relationship with respect to the work vehicle 10 equipped with the lighting device. During the operation of the work vehicle 10 equipped with a lighting device, it is possible to suppress the illuminated area 90 from moving to an unintended position on the moving surface 95. In addition, it is possible to suppress the light source 40, shaping optical system 45, and diffractive optical element 50 from shifting from their predetermined positions, thereby improving laser safety.

[0110] In the example shown in Figure 17, the shaping optical system 45 has a first lens 46, a second lens 47, and a third lens 48. The casing 70 has a cylindrical portion 71 that holds the light source 40 and the shaping optical system 45, and a lid portion 72 fixed to the cylindrical portion 71. The cylindrical portion 71 is a cylinder with one end closed. The light source 40 is fixed to the closed end of the cylindrical portion 71. The internal dimensions of the cylindrical portion 71 change via a stepped portion 71a. The internal diameter increases from the upstream side to the downstream side along the optical path of the coherent light emitted from the light source 40. The first lens 46 and the second lens 47 are mounted on each of the two stepped portions 71a. A spacing ring 73 is provided inside the cylindrical portion 71 that allows for high-precision control of the distance between the lenses. The spacing ring 73 is positioned between the first lens 46 and the second lens 47. The spacing ring 73 is positioned between the second lens 47 and the third lens 48. Furthermore, a spacing ring 73 is positioned between the lid portion 72 and the third lens 48. The spacing ring 73 suppresses relative positional displacement of each lens due to vibrations and shocks transmitted from the work vehicle 20 to the lighting device 30. The spacing ring 73 may be, for example, an annular or cylindrical member. The spacing ring 73 may be made of a metal such as aluminum, or of resin. The resin may be mixed with an inorganic material such as glass fiber to reduce the coefficient of thermal expansion. The spacing ring 73 makes it possible to suppress the shift in the parallelism of the collimated light while the work vehicle 10 with the lighting device is in motion. That is, it is possible to suppress blurring of the illuminated area 90 on the moving surface 95. As a result, it is possible to maintain high visibility of the lighting pattern and to make it easier to operate the work vehicle 20 in the direction of movement, so that work can be carried out stably.

[0111] In order to maintain a constant relative position of the light source 40, the shaping optical system 45, and the diffractive optical element 50, the light source 40, the shaping optical system 45, and the diffractive optical element 50 may be fixed to the casing 70 by fixing with adhesive, in combination with fixing by fitting.

[0112] To make fine adjustments to the relative positions of the light source 40, the shaping optical system 45, and the diffractive optical element 50, for example, spacers may be used. Thin metal plate-like materials may be used as spacers. Spacers may be used in combination with spacing rings 73 or adhesives.

[0113] Furthermore, components such as the light source 40, the shaping optical system 45, and the diffractive optical element 50 may be held by a position adjustment holder that allows for fine adjustment of their arrangement. The position adjustment holder may allow for fine adjustment of the position of the components by operating an adjustment part such as a screw. The components may be fixed to the casing 70 via the position adjustment holder. When using a position adjustment holder, the adjustment part such as a screw may be fixed with adhesive or the like after the adjustment of the position of the components is complete. In addition, the position adjustment holder may be used in combination with the spacing ring 73 described above and other members for maintaining the relative positions of the finely adjusted components.

[0114] The casing 70 may be made non-disassemblable to maintain the relative positions of components such as the light source 40, the shaping optical system 45, and the diffractive optical element 50. For example, the relative positions of components positioned by the manufacturer of the lighting device 30 may be maintained. For example, adhesive may be applied to the screw fastening or fitting parts of the casing 70 to make it non-disassemblable.

[0115] In the example shown in Figure 17, the lighting device 30 includes a battery 74, a circuit 75, and a switch 76. The battery 74 may be a primary battery or a rechargeable secondary battery. The circuit 75 is electrically connected to the battery 74 and the switch 76. When the switch 76 is operated, the circuit 75 switches between supplying power from the battery 74 to the light source 40 and stopping the power supply.

[0116] The lighting device 30 may be powered by an external power source. For example, a connector for electrically connecting to an external power source may be provided in the casing. In this example, the lighting device 30 may or may not have a primary battery or a secondary battery. A lighting device 30 without a primary or secondary battery is lighter and therefore has superior resistance to vibration and shock.

[0117] The lighting device 30 and the casing 70 may be waterproof. To provide waterproofing to the lighting device 30, waterproofing materials such as rubber or gaskets may be provided at the joints and fitting portions of the casing 70.

[0118] The lighting device 30 may have a temperature control mechanism. The temperature control mechanism may maintain the light source 40 and the circuit 75 at a temperature within a predetermined range. The temperature control mechanism may heat or cool the light source 40 and the circuit 75. The temperature control mechanism may be installed inside the casing 70. Examples of temperature control mechanisms include fans, heaters, and coolers. A heating element or Peltier element may also be used as the temperature control mechanism.

[0119] As shown in Figure 18, the lighting device 30 may have a plurality of lighting fixtures 35. In the example shown in Figure 18, each lighting fixture 35 may have the same configuration as the lighting device 30 described with reference to Figures 15 and 16. In the example shown in Figure 18, the plurality of lighting fixtures 35 may include light sources 40 that emit coherent light of different wavelengths. That is, in the example shown in Figure 18, the lighting device 30 has a plurality of light sources 40 and a plurality of diffractive optical elements 50 provided corresponding to each light source 40. The coherent light emitted from each lighting fixture 35 overlaps in the illuminated area 90 on the moving surface 95, thereby illuminating the illuminated area 90 in a desired color. The lighting device 30 shown in Figure 18 has first to third lighting devices 35A to 35C. Each lighting fixture 35A to 35C separately has light sources 40A to 40C, shaping optical systems 45A to 45C, and diffractive optical elements 50A to 50C.

[0120] In the example shown in Figure 18, multiple luminaires 35 may include light sources 40 that emit light of the same wavelength. The coherent light (illumination light) emitted from each luminaire 35 overlaps in the illuminated area 90 of the moving surface 95, thereby brightly illuminating the illuminated area 90.

[0121] In the example shown in Figure 18, the multiple lighting fixtures 35A to 35C are arranged in a third direction D3, which is the normal direction ND of the moving surface 95. The example is not limited to the one shown in Figure 18, and the multiple lighting fixtures 35A to 35C may be arranged, for example, in a second direction D2.

[0122] As shown in Figure 19, the illumination device 30 may also have a scanning device 60. The illumination device 30 shown in Figure 19 has a plurality of diffractive optical elements 50A to 50C. The scanning device 60 adjusts the optical path of the coherent light emitted from the light source 40 to control whether or not coherent light is supplied to the diffractive optical elements 50 and to distribute the coherent light to the plurality of diffractive optical elements 50A to 50C. The scanning device 60 can be constructed using various components that can change the optical path by utilizing refraction, reflection, diffraction, etc. Examples of various components that can change the optical path include lenses, prisms, mirrors, and diffractive optical elements.

[0123] The scanning device 60 changes the optical path of the coherent light from the light source 40 over time. As a result, the incident position of the coherent light shifts on multiple diffractive optical elements 50A to 50C. That is, the diffractive optical element 50 onto which the coherent light from the light source 40 is incident changes among the multiple diffractive optical elements 50A to 50C. The illustrated scanning device 60 has a reflective surface that can rotate around a single axis RA. A galvanometer mirror may be used as such a scanning device 60.

[0124] The illuminated area 90 may be divided into multiple sub-regions 93A, 93B, and 93C depending on its position in the first direction D1. Multiple diffractive optical elements 50A to 50C may illuminate different sub-regions 93A, 93B, and 93C. In this example, the diffraction angle range of the light diffracted by a single diffractive optical element 50 can be narrowed. This improves the diffraction efficiency of each diffractive optical element 50. Furthermore, because the scanning device 60 operates at a speed exceeding the resolution of human vision, it appears to a human being that all sub-regions 93A, 93B, and 93C included in the illuminated area 90 are continuously illuminated simultaneously.

[0125] In the example shown in Figure 20, the diffractive optical element 50 includes first to twelfth diffractive optical elements 50A to 50L. For example, the illuminated area 90 on the moving surface 95 is divided into first to twelfth sub-regions 93A to 93L. The coherent light diffracted by the first to twelfth diffractive optical elements 50A to 50L is projected onto separate first to twelfth sub-regions 93A to 93L. The scanning device 60 directs light from the light source 40 to each of the diffractive optical elements 50A to 50L. The illumination device 30 can control whether or not light is irradiated onto each of the diffractive optical elements 50A to 50L in accordance with the operation of the scanning device 60. For example, the light source 40 switches between emitting and stopping light emission in accordance with the operation of the scanning device 60. As another example, in accordance with the operation of the scanning device 60, a light-shielding member enters and retracts from the optical path of the light from the light source 40 in accordance with the operation of the scanning device 60. By controlling whether or not light is irradiated onto each diffractive optical element 50A to 50L, coherent light can be projected onto only any diffractive optical element 50A to 50L. This makes it possible to illuminate only any of the first to twelfth subregions 93A to 93L, and to illuminate the illuminated region 90 in a desired shape.

[0126] Furthermore, the diffractive optical element 50 included in the illumination device 30 shown in Figures 18 to 20 may be divided into multiple elemental diffractive optical elements 55.

[0127] In the embodiment described above, the work vehicle with lighting device 10 comprises a work vehicle 20 that performs work while moving, and a lighting device 30 attached to the work vehicle 20. The lighting device 30 comprises a light source 40 that emits coherent light and a diffractive optical element 50 that diffracts the coherent light. The lighting device 30 illuminates the illuminated area 90 with coherent light diffracted by the diffractive optical element 50. The illuminated area 90 is located in front of the work vehicle 20 in the direction of movement and may indicate information related to the direction of movement of the work vehicle 20. The illuminated area 90 is located in front of the work vehicle 20 in the direction of movement and may be aligned with the direction of movement.

[0128] In this embodiment, the illuminated area 90 indicates the path of the work vehicle 20 when it moves in a straight line while maintaining its current direction of movement. Therefore, while the work vehicle 20 is moving and performing work, the operator can adjust the orientation of the work vehicle 20 based on the illuminated area 90. The operator may adjust the orientation of the work vehicle 20 so that the illuminated area 90 is positioned over the target point 98, as shown in Figure 2B3. Alternatively, the operator may adjust the orientation of the work vehicle 20 so that the target point 98 is positioned on the extension of the illuminated area 90 which extends along a straight line. The operator moves the work vehicle 20 so as to maintain the alignment of the illuminated area 90 with respect to the target point 98. The operator can easily and accurately adjust the direction of movement of the work vehicle 20 in this way while observing the target point 98, which is far away. In other words, linear movement of the work vehicle 20 toward the target point 98 can be easily and stably achieved. This allows for stable linear work toward the target point 98.

[0129] Although one embodiment has been described above with reference to specific examples, the embodiment is not limited by these examples. The embodiment described above can be implemented in various other examples, and various omissions, substitutions, modifications, and additions can be made without departing from its essence.

[0130] For example, as shown in Figure 1, the work vehicle 10 with lighting equipment may have multiple lighting devices 30.

[0131] In the specific example described above, the lighting device 30 illuminates the area to be illuminated 90 located in front of the work vehicle 20 in the direction of movement. However, the example is not limited to this, and coherent light may be irradiated by another lighting device to an area to be illuminated located behind the work vehicle 20 in the direction of movement. The area to be illuminated by the other lighting device may be located on the same line as the area to be illuminated 90 illuminated by the lighting device 30. For example, if the work vehicle 20 is a line drawing machine, it is possible to confirm whether the line 97 has been drawn in the intended position. In addition, when the work vehicle reverses its direction of movement, it becomes easier to detect obstacles.

[0132] In the specific example described above, the illuminated area 90 may be observed using the observation assistance device 100. Depending on the ambient light of the environment in which the work is performed, the contrast of the illuminated area during illumination may decrease. In this case, the operator of the work vehicle may not be able to clearly observe the illuminated area. The observation assistance device 100 improves the visibility of the illuminated area 90 during illumination. By using the observation assistance device 100, the operator can clearly observe the illuminated area 90. By using the illumination device 30 and the observation assistance device 100, the operator is assisted in their work. In other words, the work assistance system 8 is composed of the illumination device 30 and the observation assistance device 100. The work assistance system 8 including the illumination device 30 and the observation assistance device 100 will be described below.

[0133] The observation support device 100 includes an optical filter 120. The transmittance of the optical filter 120 is wavelength-dependent. The optical filter 120 selectively transmits coherent light emitted from the illumination device 30 from the visible light spectrum. Visible light is light having wavelengths between 380 nm and 780 nm. More specifically, the average transmittance of the optical filter 120 in the wavelength range of coherent light projected from the illumination device 30 is higher than the average transmittance of the optical filter 120 in visible light wavelengths outside the wavelength range of coherent light.

[0134] As shown in Figures 21A to 24, the work assistance system 8 and the observation assistance device 100 may include a wearable device 104 that can be worn by the operator 4 of the work vehicle 20. The wearable device 104 includes an optical filter 120. When the operator 4 is wearing the wearable device 104, the optical filter 120 faces the operator 4's eyes. By observing the illuminated area 90 through the optical filter 120, the operator 4 can clearly observe the illuminated area 90, even in a bright environment.

[0135] As shown in Figure 21A, the device 104 may be eyeglasses. The device 104 may also be sunglasses. Figure 21B shows operator 4 wearing the sunglasses shown in Figure 21A. As shown in Figures 21A and 21B, the device 104 may include an optical filter 120, a frame 106, and a light-shielding wall portion 105. In the specific examples shown in Figures 21A and 21B, the frame 106 holds the optical filter 120. The frame 106 includes a frame body 106A that holds the optical filter 120, and a holding portion 106B for operator 4 to hold the frame body 106A. The frame body 106A holds one optical filter 120 facing the right eye and another optical filter 120 facing the left eye, similar to ordinary eyeglasses. The holding portion 106B is the ear hook portion. The light-shielding wall portion 105 is located around the optical filter 120. As shown in Figure 21B, when the operator 4 is wearing the device 104, the light-shielding wall portion 105 is positioned between the optical filter 120 and the operator 4. The light-shielding wall portion 105 has visible light shielding properties. The light-shielding wall portion 105 may also have a function to absorb visible light. The light-shielding wall portion 105 may also have a function to reflect visible light. By providing the light-shielding wall portion 105, it is possible to suppress ambient light from entering from the side between the operator 4's eyes and the optical filter 120.

[0136] Figure 21C shows another specific example of the device. As shown in Figure 21C, the device 104 may be goggles. The goggles may include a pair of optical filters 120. The goggles may include a single optical filter 120, as shown in Figure 21C. In the example shown in Figure 21C, when the operator 4 is wearing the device 104, both of the operator 4's eyes face the single optical filter 120. The device 104 shown in Figure 21C includes the optical filter 120 and a frame 106. The frame 106 includes a frame body 106A that holds the optical filter 120 and a retaining part 106B for fixing the frame body 106A to the operator 4. The retaining part 106B may be rubber that is held on the operator 4's head. A pair of ends of the retaining part 106B are connected to each end of the frame body 106A. The frame body 106A also serves as a light-shielding wall 105. The frame body 106A, which is the light-shielding wall 105, is connected to the optical filter 120 from the periphery. When the observer is wearing the wearer 104, the frame body 106A, which is the light-shielding wall 105, is positioned between the optical filter 120 and the operator 4. The frame body 106A, which is the light-shielding wall 105, can suppress ambient light from entering from the side between the optical filter 120 and the operator 4.

[0137] As shown in Figures 22A and 22B, the attachment device 104 may be goggles. In the specific examples shown in Figures 22A and 22B, the optical filter 120, which is curved to conform to the face of the operator 4, directly contacts the face of the operator 4. Holding parts 106B are connected to both ends of the optical filter 120. The pair of holding parts 106B may be made of rubber or string. As shown in Figure 22B, each holding part 106B may be hooked onto the corresponding ear. In the example shown in Figure 22B, when the attachment device 104 is worn, the periphery of the optical filter 120 contacts the face of the operator 4. This prevents ambient light from entering from the side between the optical filter 120 and the operator 4.

[0138] As shown in Figure 23, the device 104 includes an optical filter 120 and a device body 107 that is worn on the head. The device body 107 may be a helmet. The device body 107 may be a hat. The optical filter 120 may be goggles. The optical filter 120 is attached to the device body 107. When the operator 4 puts the device body 107 on their head, the optical filter 120 faces the operator 4's eyes. In the illustrated example, similar to the example in Figure 22B, the periphery of the optical filter 120 contacts the operator 4's face. This prevents ambient light from entering from the side between the optical filter 120 and the operator 4. The optical filter 120 may be detachable from the device body 107.

[0139] As shown in Figure 24, the device 104 may be a contact lens. The device 104 as a contact lens may include a contact lens body 108 and an optical filter 120 laminated on the contact lens body 108. When the operator 4 wears the contact lens on their eye, the optical filter 120 faces the eye via the contact lens body 108. At this time, since the contact lens body 108 is in contact with the eye, ambient light entering from the side between the optical filter 120 and the operator 4 can be suppressed.

[0140] As shown in Figure 25, the work assistance system 8 and the observation assistance device 100 may include an imaging device 101. The imaging device 101 includes an optical filter 120 and an image sensor 101a. Light transmitted through the optical filter 120 is incident on the image sensor 101a. The imaging device 101 images the moving surface 95 including the illuminated area 90. The operator 4 observes the moving surface 95 imaged by the imaging device 101. This allows the operator 4 to clearly observe the illuminated area 90, distinguishing it from adjacent areas, even in a bright environment.

[0141] As shown in Figure 25, the work assistance system 8 and the observation assistance device 100 may include a display device 102 electrically connected to the imaging device 101. The display device 102 displays the image captured by the imaging device 101. The operator 4 can clearly observe the illuminated area 90 displayed on the display device 102, distinguishing it from adjacent areas.

[0142] Figure 26A shows an example of the transmission spectrum of the optical filter 120 in the visible light range. The optical filter 120 may selectively transmit only the coherent light projected from the illumination device 30. In this embodiment, the average transmittance of the optical filter 120 in the coherent light wavelength range is higher than the average transmittance of the optical filter 120 in the visible light wavelength range other than the coherent light wavelength range. As a result, even if the amount of ambient light such as sunlight irradiating the moving surface 95 is large, the operator 4 can clearly observe the illuminated area 90 on the moving surface 95 by distinguishing it from adjacent areas through the optical filter 120. In order to expect this function of the optical filter 120, the wavelength range of the coherent light projected from the illumination device 30 may be sufficiently narrow.

[0143] The transmittance (%) refers to the total light transmittance (%) measured at an incident angle of 0° using a spectrophotometer (Shimadzu Corporation "UV-3100PC", compliant with JIS K 0115). The average transmittance (%) is the average value of the transmittance (%) measured every 1 nm in the target wavelength range. The wavelength of visible light is between 380 nm and 780 nm.

[0144] As an example, let's assume that the wavelength of coherent light is a single wavelength of 530 nm. In this assumption, the "average transmittance of optical filter 120 in the wavelength range of coherent light" is the total light transmittance (%) value of optical filter 120 for light with a wavelength of 530 nm. In this assumption, the "average transmittance of optical filter 120 in the visible light wavelength range other than the wavelength range of coherent light" means the average value of the transmittance (%) measured at 1 nm intervals in the wavelength ranges of 380 nm to 529 nm and 531 nm to 780 nm.

[0145] A lower limit may be set for the average transmittance of the optical filter 120 in the wavelength range of coherent light. By setting this lower limit for average transmittance, coherent light can be transmitted through the optical filter 120 with high transmittance. The operator 4 can clearly observe the illuminated area 90 through the optical filter 120. The average transmittance of the optical filter 120 in the wavelength range of coherent light may be 50% or more, 70% or more, or 80% or more.

[0146] Similarly, a lower limit may be set on the maximum transmittance of the optical filter 120 in the visible light range. By setting this lower limit on the maximum transmittance, coherent light can be transmitted through the optical filter 120 with high transmittance. Operator 4 can clearly observe the illuminated area 90 through the optical filter 120. The maximum transmittance of the optical filter 120 in the visible light range may be 50% or more, 70% or more, or 80% or more. Note that if the coherent light is of a single wavelength, the average transmittance (%) of the optical filter 120 in the wavelength range of the coherent light and the maximum transmittance (%) of the optical filter 120 in the visible light range may be the same.

[0147] The full width at half maximum (FWHM) of an optical filter refers to the wavelength range (nm) over which a transmittance of more than half of the maximum transmittance can be obtained. An upper limit may be set for the FWHM of the optical filter. By setting an upper limit for the FWHM, coherent light in a specific wavelength range can be concentrated and transmitted through the optical filter 120. Coherent light can be concentrated and transmitted through the optical filter 120. At the same time, the transmission of ambient light such as sunlight through the optical filter 120 can be suppressed. Therefore, when observing the illuminated area 90 through the optical filter 120, the ambient light can be weakened and the illuminated area 90 can be emphasized. In other words, the contrast of the illuminated area 90 can be improved. As a result, the illuminated area 90 can be observed clearly. From this viewpoint, the FWHM of the optical filter may be 15 nm or less, 3 nm or less, or 1 nm or less.

[0148] An upper limit may be set on the average transmittance of the optical filter 120 in the visible light wavelength range other than the coherent light wavelength range. By setting this upper limit on the average transmittance, it is possible to suppress the transmission of ambient light such as sunlight through the optical filter 120. As a result, the contrast of the illuminated area 90 is improved, and the illuminated area 90 can be observed clearly. The average transmittance of the optical filter 120 in the visible light wavelength range other than the coherent light wavelength range may be 1% or less, 0.1% or less, or 0.01% or less.

[0149] A lower limit may be set for the average transmittance of the optical filter 120 in the visible light wavelength range other than the coherent light wavelength range. By setting this lower limit for average transmittance, the relative position of the illuminated area 90 with respect to the surrounding environment can be determined via the optical filter 120 even when the amount of ambient light is low, such as at night. This allows for clear observation of the illuminated area 90 via the optical filter 120 in both cases, while maintaining the same handling of the optical filter 120 whether the moving surface 95 is bright or dark. The average transmittance of the optical filter 120 in the visible light wavelength range other than the coherent light wavelength range may be 0.001% or higher, 0.005% or higher, or 0.01% or higher.

[0150] An upper limit may be set on the average transmittance of the optical filter 120 in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of coherent light. By setting this upper limit on the average transmittance, it is possible to concentrate the transmission of coherent light through the optical filter 120 while suppressing the transmission of ambient light such as sunlight through the optical filter 120. This makes it possible to concentrate the transmission of coherent light in a specific wavelength range through the optical filter 120. The average transmittance of the optical filter 120 in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of coherent light may be 1% or less, 0.1% or less, or 0.01% or less.

[0151] The central wavelength of coherent light refers to the wavelength with the highest intensity among the coherent light emitted from the lighting device 30.

[0152] A lower limit may be set on the average transmittance of the optical filter 120 in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of coherent light. By setting this lower limit on the average transmittance, the relative position of the illuminated area 90 with respect to the surrounding environment can be determined via the optical filter 120 even when the amount of ambient light is low, such as at night. This allows for clear observation of the illuminated area 90 via the optical filter 120 in both cases, while maintaining the same handling of the optical filter 120 whether the moving surface 95 is bright or dark. The average transmittance of the optical filter 120 in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of coherent light may be 0.001% or higher, 0.005% or higher, or 0.01% or higher.

[0153] Furthermore, if multiple candidate upper and lower limits are given for numerical ranges such as transmittance, full width at half maximum, and illuminance, the numerical range may be constructed by combining any one candidate upper limit and any one candidate lower limit. For example, consider the case where it is written that "Numerical value B may be A1 or greater, A2 or greater, or A3 or greater. Numerical value B may be A4 or less, A5 or less, or A6 or less." In this case, the numerical range of numerical value B may be A1 or greater and A4 or less, A1 or greater and A5 or less, A1 or greater and A6 or less, A2 or greater and A4 or less, A2 or greater and A5 or less, A2 or greater and A6 or less, A3 or greater and A4 or less, A3 or greater and A5 or less, or A3 or greater and A6 or less.

[0154] The optical filter 120 is not particularly limited as long as it has wavelength-selective transmission. The optical filter 120 may include a dielectric multilayer film 122. The dielectric multilayer film 122 is superior in that it offers a high degree of design freedom for transmission characteristics.

[0155] Figure 26B is a cross-sectional view showing an example of the layer configuration of the optical filter 120. The optical filter 120 shown in Figure 26B includes a first protective layer, a second protective layer, and a dielectric multilayer film 122 located between the first protective layer 121A and the second protective layer 121B.

[0156] The dielectric multilayer film 122 may include alternately stacked low refractive index layers 122a and high refractive index layers 122b. The low refractive index layers 122a and high refractive index layers 122b may be inorganic layers containing an inorganic compound. The low refractive index layers 122a and high refractive index layers 122b may be resin layers.

[0157] The dielectric multilayer film 122 transmits light in a specific wavelength range and reflects light in wavelength ranges other than that specific wavelength range. Ambient light that passes through the optical filter 120 and enters the space between the operator's eye 4 and the optical filter 120 travels towards the observer's eye. On the other hand, ambient light that enters the space between the operator's eye 4 and the optical filter 120 from the side may enter the surface of the optical filter 120 facing the operator 4 and be reflected with high reflectivity. This reflection makes the surface of the optical filter 120 facing the operator 4 mirror-like, reducing the visibility of the illuminated area 90. As described above, the optical filter 120 may be in contact with the operator's face to suppress the incidence of ambient light such as sunlight into the space between the operator's eye 4 and the optical filter 120. The light-shielding wall portion 105 may also be used to suppress the incidence of ambient light such as sunlight into the space between the operator's eye 4 and the optical filter 120 from the side. The average transmittance of the light-shielding wall portion 105 in the visible light wavelength range may be 0%.

[0158] Next, we will explain how the work assistance system 8 and the observation assistance device 100 work together.

[0159] In this example, the work assistance system 8 includes an observation assistance device 100 in addition to the illumination device 30. The observation assistance device 100 includes an optical filter 120. The average transmittance of the optical filter 120 in the wavelength range of coherent light projected from the illumination device 30 is higher than the average transmittance of the optical filter 120 in the visible light wavelength range other than the coherent light wavelength range. By observing the illuminated area 90 illuminated through this optical filter 120, the brightness of ambient light can be suppressed while maintaining the brightness of the illuminated area 90. This improves the contrast of the illuminated area 90, allowing for clear observation of the illuminated area 90.

[0160] In the examples shown in Figures 21 to 24, the observation assistance device 100 includes a wearable device 104. When the operator 4 is wearing the wearable device 104, the optical filter 120 faces the operator 4's eyes. That is, by wearing the wearable device 104, the operator 4 can observe the illuminated area 90 and the moving surface 95 through the optical filter 120. Since the optical filter 120 does not need to be held by hand, the operator 4 can use both hands freely while clearly observing the illuminated area 90. For example, the operator 4 can perform tasks stably while clearly observing the illuminated area 90.

[0161] The device 104 shown in Figures 21A to 21C may be eyeglasses, sunglasses, or goggles. The illustrated device 104 includes a light-shielding wall 105 located around the optical filter 120. When the operator 4 is wearing the device 104, the light-shielding wall 105 is located between the optical filter 120 and the operator 4. By blocking ambient light, the light-shielding wall 105 can prevent ambient light from entering the space between the optical filter 120 and the operator 4 from the side. Therefore, when using a reflective optical filter 120, it is possible to suppress the reduction in visibility of the illuminated area 90 due to the reflection of ambient light by the optical filter 120.

[0162] The device 104 shown in Figure 24 is a contact lens. In this example as well, the operator 4 does not need to hold the optical filter 120 with their hand. Therefore, the operator 4 can use both hands freely while observing the illuminated area 90. Also, the contact lens body 108 is positioned between the optical filter 120 and the operator 4's eye. Therefore, it is possible to suppress ambient light from entering and reflecting off the surface of the optical filter 120 that faces the operator 4's eye.

[0163] In the example shown in Figure 25, the observation assistance device 100 includes an imaging device 101. The imaging device 101 images the illuminated area 90 via an optical filter 120. The imaging device 101 significantly reduces ambient light using the optical filter 120 to image the illuminated area 90 and its surroundings. Therefore, by using the imaging device 101, the illuminated area 90 can be clearly observed. In the example shown in Figure 25, the observation assistance device 100 includes a display device 102 electrically connected to the imaging device 101. The display device 102 displays the image captured by the imaging device 101, i.e., the illuminated area 90. The display device 102 displays the illuminated area 90 with improved contrast. The operator 4 can clearly observe the illuminated area 90 displayed by the display device 102. The display device 102 may be a display device of a navigation system that shows the planned route of the work vehicle.

[0164] As described above, the average transmittance of the optical filter 120 in the wavelength range of the coherent light projected from the illumination device 30 may be 50% or more, 70% or more, or 80% or more. The maximum transmittance of the optical filter 120 in the visible light range may be 50% or more, 70% or more, or 80% or more. The wavelength range of the coherent light projected from the illumination device 30 may include the wavelength at which the transmittance of the optical filter 120 is maximum. According to these examples, the brightness of the illuminated area 90 can be maintained when the illuminated area 90 is observed through the optical filter 120. This allows the illuminated area 90 to be clearly observed.

[0165] The average transmittance of the optical filter 120 in the visible light wavelength range other than the wavelength range of the coherent light projected from the lighting device 30 may be 1% or less, 0.1% or less, or 0.01% or less. The average transmittance of the optical filter 120 in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of the coherent light projected from the lighting device 30 may be 1% or less, 0.1% or less, or 0.01% or less. According to these examples, it is possible to suppress the transmission of ambient light such as sunlight through the optical filter 120. As a result, the contrast of the illuminated area 90 is improved, and the illuminated area 90 can be clearly observed.

[0166] The full width at half maximum (FWHM) of the optical filter may be 15 nm or less, 3 nm or less, or 1 nm or less. In this example, when observed through the optical filter 120, ambient light can be reduced while maintaining the brightness of the illuminated area 90. This improves the clarity of the illuminated area 90, allowing for clear observation of the illuminated area 90. The full width at half maximum (FWHM) of the optical filter may include the entire wavelength range of the coherent light emitted from the illumination device 30.

[0167] The average transmittance of the optical filter 120 in the visible light wavelength range other than the wavelength range of the coherent light emitted from the lighting device 30 may be 0.001% or more, 0.005% or more, or 0.01% or more. The average transmittance of the optical filter 120 in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of the coherent light emitted from the lighting device 30 may be 0.001% or more, 0.005% or more, or 0.01% or more. According to these examples, even when the amount of ambient light is low, such as at night, the relative position of the illuminated area 90 with respect to the surrounding environment can be determined via the optical filter 120. For example, the illuminated area 90 can be clearly observed in both cases, while handling the optical filter 120 the same way whether the moving surface 95 is bright or dark.

[0168] A lower limit may be set on the maximum illuminance of the illuminated area 90 caused by the coherent light projected from the lighting device 30. Here, "illuminance of the illuminated area 90 caused by coherent light" refers to the illuminance in the illuminated area 90 caused solely by the coherent light projected from the lighting device 30. Therefore, the difference between the illuminance measured at a certain position within the illuminated area 90 when the illuminated area 90 is illuminated and the illuminance measured at the same position within the illuminated area 90 when the illuminated area 90 is not illuminated is the "illuminance of the illuminated area 90 caused by coherent light". By setting a lower limit on the maximum illuminance of the illuminated area 90, the illuminated area 90 can be observed brightly and clearly. The maximum illuminance of the illuminated area 90 caused by the coherent light projected from the lighting device 30 may be 1 lx or more, 0.1 lx or more, or 0.01 lx or more.

[0169] An upper limit may be set on the maximum illuminance of the illuminated area 90 caused by the coherent light projected from the lighting device 30. If the illuminance of the illuminated area 90 is made too high, the visibility of the illuminated area 90 will not be effectively improved, and energy efficiency will deteriorate. From this point of view, the maximum illuminance of the illuminated area 90 caused by the coherent light projected from the lighting device 30 may be 1000 lx or less, 100 lx or less, or 10 lx or less.

[0170] The maximum illuminance of the illuminated area 90 due to the coherent light projected from the lighting device 30 is defined as illuminance LX (lx). The illuminance due to ambient light at the position within the illuminated area 90 where illuminance LX is obtained is defined as illuminance LY (lx). Illuminance LY is measured on the moving surface 95 when the illuminated area 90 is not illuminated. The average transmittance of the optical filter 120 in the wavelength range of the coherent light projected from the lighting device 30 is defined as transmittance TX (%). The average transmittance of the optical filter 120 in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of the coherent light projected from the lighting device 30 is defined as transmittance TY (%). In this case, illuminance LX, illuminance LY, transmittance TX, and transmittance TY may satisfy the following relationship. 0.001 ≤ (LX·TX) / (LY·TY) In this example, the contrast of the illuminated area 90 is improved, and the illuminated area 90 can be clearly observed and distinguished from adjacent areas. From the perspective of improving the visibility of the illuminated area 90, "(LX·TX) / (LY·TY)" may be 0.01 or greater, or 0.1 or greater.

[0171] Illuminance LX, illuminance LY, transmittance TX, and transmittance TY may satisfy the following relationship. (LX·TX) / (LY·TY) ≤ 10 In this example, it is possible to prevent the area around the illuminated region 90 from becoming too dark. That is, even when the amount of ambient light is low, the relative position of the illuminated region 90 with respect to the surrounding environment can be determined via the optical filter 120. For example, while handling the optical filter 120 the same way whether the moving surface 95 is bright or dark, the illuminated region 90 can be clearly observed and distinguished from adjacent areas in both cases.

[0172] Illuminance values ​​shall be those measured using a Konica Minolta CL-500A spectroradiometer in accordance with JIS (JIS C 1609-1:2006). [Explanation of symbols]

[0173] 5: Work support device, 10: Work vehicle with lighting device, 20: Work vehicle, 21: Body, 22: Wheels, 23: Drive unit, 24: Handle, 25: Work device, 26: Colorant holding unit, 27: Supply unit, 27a: Supply port, 30: Lighting device, 31: Outlet, 35: Lighting fixture, 40: Light source, 45: Shaping optical system, 46: First lens, 47: Second lens, 48: Third lens, 49: Optical element, 50: Diffractive optical element, 55 :Elemental diffractive optical element, 60:Scanning device, 70:Casing, 71:Cylindrical part, 71a:Stepped part, 72:Lid part, 73:Spacing ring, 75:Circuit, 76:Switch, 74:Battery, 95:Moving surface, 97:Line, 90:Illuminated area, 90a:Elemental area, 91:First area, 92:Second area, 93A,93B,93C:Partial areas, 98:Target point, D1:First direction D1, D2:Second direction D2, D3:Third direction D3

Claims

1. A work vehicle that performs tasks while moving, The work vehicle has a lighting device that is attached to it, The illumination device comprises a light source that emits coherent light and a diffractive optical element that diffracts the coherent light from the light source. The lighting device illuminates the area to be illuminated, including the area located in front of the work vehicle in the direction of movement, with coherent light diffracted by the diffractive optical element. The illuminated area is a work vehicle equipped with a lighting device that displays information related to the direction of movement of the work vehicle.

2. The work vehicle with a lighting device according to claim 1, wherein the illuminated area extends along the direction of movement.

3. A work vehicle that performs tasks while moving, The work vehicle has a lighting device that is attached to it, The illumination device comprises a light source that emits coherent light and a diffractive optical element that diffracts the coherent light from the light source. The lighting device illuminates the area to be illuminated, including the area located in front of the work vehicle in the direction of movement, with coherent light diffracted by the diffractive optical element. The illuminated area is a work vehicle equipped with a lighting device, extending along the direction of movement.

4. The work vehicle with lighting device according to claim 2 or 3, wherein the illuminated area includes a linear or dotted line first area extending along the direction of movement.

5. The work vehicle with lighting device according to claim 4, wherein the illuminated area further includes a second area extending in a direction nonparallel to the direction of movement.

6. The illuminated region further includes a plurality of second regions extending from the first region in a direction nonparallel to the direction of movement, The work vehicle with lighting device according to claim 4, wherein the multiple second regions are positioned at intervals in the direction of movement.

7. A work vehicle with a lighting device according to any one of claims 1 to 3, wherein the length of the illuminated area along the direction of movement on the moving surface on which the work vehicle moves is 3 m or more and 100 m or less.

8. The work vehicle with a lighting device according to claim 7, wherein the width of the illuminated area along the direction perpendicular to the direction of movement on the moving surface is 0.002 m or more and 0.2 m or less.

9. A work vehicle with a lighting device according to any one of claims 1 to 3, wherein the ratio of the length of the illuminated area along the direction of movement on the moving surface of the work vehicle to the width of the illuminated area along a direction perpendicular to the direction of movement on the moving surface is 25 or more and 10000 or less.

10. The lighting device has a casing that houses the light source, A work vehicle with a lighting device according to any one of claims 1 to 3, wherein the light source and the diffractive optical element are fixed to the casing.

11. The lighting device comprises a casing for housing the light source and a shaping optical system for shaping the light from the light source. A work vehicle with a lighting device according to any one of claims 1 to 3, wherein the light source, the shaping optical system, and the diffractive optical element are fixed to the casing.

12. The work vehicle with a lighting device according to any one of claims 1 to 3, wherein the lighting device is mounted on the work vehicle so as to be adjustable in the vertical direction.

13. The work vehicle with a lighting device according to any one of claims 1 to 3, wherein the lighting device is mounted on the work vehicle so as to be adjustable in the left-right direction.

14. The work vehicle with a lighting device according to any one of claims 1 to 3, wherein the lighting device is mounted on the work vehicle so as to be able to adjust its rotational position about an axis that is not parallel in both the left-right and up-down directions.

15. The work vehicle with a lighting device according to any one of claims 1 to 3, wherein the lighting device is mounted on the work vehicle so as to be adjustable in position in at least one of the left-right direction and the up-down direction.

16. The work vehicle with a lighting device according to any one of claims 1 to 3, wherein the illuminated area includes at least a portion of the area where work is being performed by the work vehicle.

17. The illuminated area includes at least a portion of the area in which the work vehicle is located in the direction of movement, according to any one of claims 1 to 3.

18. The work vehicle with a lighting device according to any one of claims 1 to 3, wherein the illuminated area includes an area located behind the work vehicle in the direction of movement of the work vehicle.

19. A lighting device used in a work vehicle that performs work while moving, A lighting device comprising a light source that emits coherent light, and a diffractive optical element that diffracts the coherent light from the light source.

20. The coherent light diffracted by the diffractive optical element illuminates the area to be illuminated, including the area located in front of the work vehicle in the direction of movement. The lighting device according to claim 19, wherein the illuminated area indicates information related to the direction of movement of the work vehicle.

21. The coherent light diffracted by the diffractive optical element illuminates the area to be illuminated, including the area located in front of the work vehicle in the direction of movement. The lighting device according to claim 19 or 20, wherein the illuminated area extends along the direction of movement.

22. Lighting equipment used in work vehicles that perform tasks while moving towards a target location, The system comprises a target installed at the aforementioned target location, The aforementioned lighting device is a work support device comprising a light source that emits coherent light and a diffractive optical element that diffracts the coherent light from the light source.

23. Lighting equipment used in work vehicles that perform tasks while moving towards a target location, The optical filter comprises an optical filter whose average transmittance in the wavelength range of coherent light projected from the illumination device is higher than the average transmittance in the visible light wavelength range other than the wavelength range of coherent light. The lighting device is a work assistance system that illuminates a light-to-be-illuminated area, including an area located in front of the work vehicle in the direction of movement, with the coherent light.

24. The work assistance system according to claim 23, wherein the illuminated area is observed through the optical filter.

25. The work vehicle is equipped with a device that can be worn by the operator of the work vehicle, The aforementioned mounting device includes the optical filter, The work assistance system according to claim 23 or 24, wherein, when the operator is wearing the attachment, the optical filter faces the operator's eye.

26. The mounting device includes a light-shielding wall portion located around the optical filter, The work assistance system according to claim 25, wherein, when the operator is wearing the attachment, the light-shielding wall is positioned between the optical filter and the operator.

27. The work assistance system according to claim 23 or 24, comprising an imaging device including the aforementioned optical filter.

28. The imaging device is equipped with a display device that is electrically connected to it, The work assistance system according to claim 27, wherein the display device displays an image captured by the imaging device.

29. The work assistance system according to claim 23 or 24, wherein the full width at half maximum of the optical filter is 15 nm or less.

30. The work assistance system according to claim 23 or 24, wherein the maximum transmittance of the optical filter in the visible light range is 50% or more.

31. The work assistance system according to claim 23 or 24, wherein the average transmittance of the optical filter in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of the coherent light is 1% or less.

32. The work assistance system according to claim 23 or 24, wherein the average transmittance of the optical filter in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of the coherent light is 0.001% or more.

33. The work assistance system according to claim 23 or 24, wherein the maximum illuminance of the illuminated area due to the coherent light is 1 lx or more.

34. The illuminance LX (lx) is the maximum value of the illuminance of the illuminated area caused by the coherent light, The illuminance LY(lx) at the position within the illuminated area where the illuminance LX is obtained is due to ambient light, The average transmittance TX (%) of the optical filter in the wavelength range of the coherent light, The average transmittance TY (%) of the optical filter in the visible light wavelength range other than the 30 nm wavelength range centered on the central wavelength of the coherent light satisfies the following relationship: 0.001 ≦ (LX・TX) / (LY・TY) The work assistance system according to claim 23 or 24.

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