Observation auxiliary device

Abstract

To observe a projection pattern clearly.SOLUTION: A projection system 10 comprises an illumination device 30 and an optical filter 120. The illumination device emits illumination light. The illumination device projects a projection pattern 90 onto a projection surface 95. An average transmittance of the optical filter in a wavelength range of the illumination light emitted from the illumination device is higher than an average transmittance of the optical filter in a visible light wavelength range other than the wavelength range of the illumination light.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an observation assistance device. [Background technology]

[0002] There is known an illumination device that projects a projection pattern onto a projection surface such as a road surface (for example, JP2021-52008A). Depending on the ambient light of the environment in which the illumination device is used, the contrast of the projection pattern decreases, making it difficult to observe the projection pattern. DISCLOSURE OF THEINVENTION

[0003] The present disclosure aims to make the projected pattern clearly observable.

[0004] According to one embodiment of the present disclosure, a projection system includes: an illumination device that emits illumination light to project a projection pattern onto a projection surface; an optical filter having an average transmittance in the wavelength range of the illumination light higher than an average transmittance in a visible light wavelength range other than the wavelength range of the illumination light; the wavelength range of the illumination light is a wavelength range of at least a wavelength 5 nm lower than a peak wavelength of the illumination light, and at most a wavelength 5 nm higher than the peak wavelength of the illumination light, The peak wavelength of the illumination light is the wavelength at which the maximum radiant flux of the illumination light is obtained.

[0005] A first observation assistance device according to an embodiment of the present disclosure, An observation assistance device that assists in observation of a projection pattern projected onto a projection surface using illumination light emitted from an illumination device, comprising: an optical filter having an average transmittance in the wavelength range of the illumination light higher than an average transmittance in a visible light wavelength range other than the wavelength range of the illumination light; the wavelength range of the illumination light is a wavelength range of at least a wavelength 5 nm lower than a peak wavelength of the illumination light, and at most a wavelength 5 nm higher than the peak wavelength of the illumination light, The peak wavelength of the illumination light is the wavelength at which the maximum radiant flux of the illumination light is obtained.

[0006] A second observation assistance device according to an embodiment of the present disclosure, An observation assistance device that assists in observation of a pattern displayed on a surface, comprising: a display device that displays an image of the surface; A control device electrically connected to the display device, the controller detects the pattern in the image displayed on the display device and generates a display pattern related to the detected pattern; The display device displays the display pattern superimposed on the image.

[0007] According to an embodiment of the present disclosure, the projection pattern can be clearly observed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram for explaining an embodiment, and is a perspective view showing an example of a projection system and an observation auxiliary device. [Figure 2A] FIG. 2A is a perspective view showing an example of an observation auxiliary device. [Figure 2B] FIG. 2B is a perspective view showing an observer wearing the observation assistant device shown in FIG. 2A. [Figure 2C] FIG. 2C is a perspective view showing a modified example of the observation auxiliary device shown in FIG. 2A. [Figure 3A] FIG. 3A is a perspective view showing another example of the observation auxiliary device. [Figure 3B] FIG. 3B is a perspective view showing an observer wearing the observation assistant device shown in FIG. 3A. [Figure 4] FIG. 4 is a side view showing still another example of the observation auxiliary device together with an observer. [Diagram 5] FIG. 5 is a side sectional view showing still another example of the observation auxiliary device. [Figure 6] FIG. 6 is a side view showing another example of the projection system and the observation auxiliary device. [Figure 7A]FIG. 7A is a graph showing an example of a transmission spectrum of an optical filter that can be included in the projection system and the observation assistant device. [Figure 7B] FIG. 7B is a cross-sectional view showing an example of a layer configuration of an optical filter that can be included in the projection system and the observation auxiliary device. [Figure 8] FIG. 8 is a perspective view illustrating an example of a lighting device. [Figure 9] FIG. 9 is a perspective view showing another example of the lighting device. [Figure 10] FIG. 10 is a cross-sectional view showing still another example of the lighting device. [Figure 11] FIG. 11 is a side view showing still another example of the lighting device. [Figure 12] FIG. 12 is a diagram illustrating still another example of the lighting device. [Figure 13] FIG. 13 is a side view showing still another example of the observation auxiliary device. [Figure 14] FIG. 14 is a plan view showing a display device that can be included in the observation auxiliary device of FIG. [Figure 15] FIG. 15 is a vertical cross-sectional view showing an example of a moving body. [Figure 16] FIG. 16 is a perspective view showing a wearable display device. [Figure 17] FIG. 17 is a side view showing still another example of the projection system and the observation auxiliary device. [Figure 18A] FIG. 18A is a diagram corresponding to FIG. 14, showing the display surface of the display device. [Figure 18B] FIG. 18B is a diagram corresponding to FIG. 14, showing the display surface of the display device. [Figure 18C] FIG. 18C is a diagram corresponding to FIG. 14, showing the display surface of the display device. [Figure 18D] FIG. 18D corresponds to FIG. 14 and shows the display surface of the display device. [Figure 18E] FIG. 18E is a diagram corresponding to FIG. 14, showing the display surface of the display device. [Figure 19]FIG. 19 is a flowchart illustrating an example of a method for generating a display pattern by a control device. [Figure 20] FIG. 20 is a side view showing still another example of the projection system and the observation auxiliary device. [Figure 21] FIG. 21 is a side view showing still another example of the projection system and the observation auxiliary device. [Figure 22] FIG. 22 is a plan view showing a modified example of the projection pattern and the display pattern. [Diagram 23] FIG. 23 is a plan view showing another modified example of the projection pattern and the display pattern. [Figure 24] FIG. 24 corresponds to FIG. 14 and shows the display surface of the display device. [Diagram 25] FIG. 25 corresponds to FIG. 1 and is a perspective view for explaining a drawback of the conventional technique. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] One embodiment of the present disclosure relates to the following [1] to

[40] .

[0010] [1] an illumination device that emits illumination light to project a projection pattern onto a projection surface; an optical filter having an average transmittance in the wavelength range of the illumination light higher than an average transmittance in a visible light wavelength range other than the wavelength range of the illumination light; the wavelength range of the illumination light is a wavelength range of at least a wavelength 5 nm lower than a peak wavelength of the illumination light, and at most a wavelength 5 nm higher than the peak wavelength of the illumination light, A projection system, wherein the peak wavelength of the illumination light is the wavelength at which a maximum radiant flux of the illumination light is obtained.

[0011] [2] 13. The projection system of claim 1, wherein the projected pattern is observed through the optical filter.

[0012] [3] a wearing device that can be worn by an observer of the projection pattern; the mounting includes the optical filter, The projection system according to claim 1 or 2, wherein the optical filter faces the observer's eye when the observer wears the wearing device.

[0013] [4] the mounting fixture includes a light-shielding wall portion located around the optical filter, The projection system according to [3], wherein when the observer wears the mounting fixture, the light-shielding wall portion is positioned between the optical filter and the observer.

[0014] [5] The wearing device includes a wearing device main body to be worn on a head, The projection system of any one of [3] and [4], wherein the optical filter is detachable from the mounting body.

[0015] [6] The projection system of [3], wherein the mounting includes a contact lens that includes the optical filter.

[0016] [7] The projection system according to [1] or [2], wherein the optical filter constitutes a windshield for a moving object.

[0017] [8] The projection system described in [1], comprising an imaging device including the optical filter.

[0018] [9] a display device electrically connected to the imaging device; The projection system according to [8], wherein the display device displays an image captured by the imaging device.

[0019]

[10] The display device includes a wearing device that can be worn by an observer, and a display element that is held by the wearing device and displays the image, The projection system according to [9], wherein when the observer wears the wearing device, the display element faces the observer's eye.

[0020]

[11] The projection system according to

[10] , wherein the display element has a total light transmittance of 1% or more.

[0021]

[12] a control device electrically connected to the imaging device and the display device; the control device detects the projection pattern in the image displayed on the display device and generates a display pattern related to the detected projection pattern; The projection system according to any one of [9] to

[11] , wherein the display device displays the display pattern superimposed on the image.

[0022]

[13] the projection pattern includes a linear pattern, The projection system according to

[12] , wherein the display pattern includes a linear auxiliary pattern extending on an extension line of the projection pattern.

[0023]

[14] the projection pattern includes a linear pattern, The projection system according to

[12] or

[13] , wherein the display pattern includes a linear auxiliary pattern located on an extension of the projection pattern.

[0024]

[15] the projection pattern includes a first linear pattern and a second linear pattern intersecting each other, The projection system described in

[12] or

[13] , wherein the display pattern includes a first linear auxiliary pattern located on an extension of the first linear pattern, and a second linear auxiliary pattern located on an extension of the second linear pattern.

[0025]

[16] The projection system according to claim 12, wherein the display pattern includes an auxiliary pattern that circumferentially surrounds the projection pattern.

[0026]

[17] The projection system according to

[16] , wherein the center of gravity of the area surrounded by the outer contour of the auxiliary pattern is at the same position as at least one of the center of gravity of the projection pattern and the center of gravity of the area surrounded by the outer contour of the projection pattern.

[0027]

[18] The projection system according to any one of

[12] to

[17] , wherein the display pattern includes a detection pattern that overlaps with the detected projection pattern.

[0028]

[19] The projection system according to any one of

[12] to

[18] , wherein the display pattern includes an auxiliary pattern that is connected to the detection pattern and is located on an extension of the detection pattern.

[0029]

[20] the imaging device is movable relative to the projection surface, The projection system described in any one of [9] to

[19] , wherein the display device displays a reference pattern indicating a predetermined position, a predetermined direction, or a predetermined range within the range imaged by the imaging device, superimposed on the image.

[0030] [twenty one] a movable body that is movable relative to the projection surface, The projection system according to

[20] , wherein the imaging device is held by the moving body.

[0031] [twenty two] The projection system according to

[21] , wherein the reference pattern indicates at least one of a planned path of movement of the moving body and a planned location of work to be performed by the moving body.

[0032] [twenty three] the display device displays a reference pattern indicating a predetermined position, a predetermined direction, or a predetermined range within a range captured by the imaging device, superimposed on the image; the control device evaluates a positional relationship of at least one of the detected projection pattern and the generated display pattern with respect to the reference pattern; The projection system according to any one of

[12] to

[22] , wherein, when the control device determines that there is an abnormality in the positional relationship, the abnormality is notified.

[0033] [twenty four] The projection system according to

[23] , wherein the display device notifies the abnormality by changing a display method of at least one of the image and the display pattern.

[0034] [twenty five] A notification device is provided to notify the abnormality, The projection system according to claim 23 or 24, wherein, when the control device determines that there is an abnormality in the positional relationship, the alarm device alerts the user of the abnormality using at least one of light and sound.

[0035]

[26] The projection system according to any one of

[23] to

[25] , wherein the illumination device notifies of the abnormality by changing a method of projecting the projection pattern onto the projection surface.

[0036]

[27] The projection system according to any one of [1] to

[26] , wherein the optical filter includes a dielectric multilayer film.

[0037]

[28] The projection system according to any one of [1] to

[27] , wherein the full width at half maximum of the spectral transmittance of the optical filter is 15 nm or less.

[0038]

[29] The projection system according to any one of [1] to

[28] , wherein the optical filter has a maximum spectral transmittance of 50% or more in the visible light region.

[0039]

[30] The projection system according to any one of [1] to

[29] , wherein the average transmittance of the optical filter in a visible light wavelength range other than a wavelength range of 30 nm centered on the peak wavelength of the illumination light is 1% or less.

[0040]

[31] The projection system according to any one of [1] to

[30] , wherein the average transmittance of the optical filter in a visible light wavelength range other than a wavelength range of 30 nm centered on a peak wavelength of the illumination light is 0.001% or more.

[0041]

[32] The projection system according to any one of [1] to

[31] , wherein a maximum value of illuminance of the projection pattern projected onto the projection surface is 1 lx or more.

[0042]

[33] an illuminance LX (lx) which is the maximum illuminance of the projection pattern projected onto the projection surface; Illuminance LY(lx) due to ambient light at a position on the projection surface at which the illuminance LX is obtained; and an average transmittance TX (%) of the optical filter in the wavelength range of the illumination light; and an average transmittance TY (%) of the optical filter in a visible light wavelength range other than a wavelength range of 30 nm centered on the peak wavelength of the illumination light, which satisfies the following relationship: 0.001≦(LX TX) / (LY TY) The projection system according to any one of [1] to

[32] .

[0043]

[34] The illuminance LX, the illuminance LY, the transmittance TX, and the transmittance TY satisfy the following relationship: (LX TX) / (LY TY) ≦ 10

[33] .

[0044]

[35] The projection system according to any one of [1] to

[34] , wherein the illumination device includes a light source that emits coherent light as the illumination light, and a diffractive optical element that diffracts the coherent light.

[0045]

[36] An observation assistance device that assists in observation of a projection pattern projected onto a projection surface using illumination light emitted from an illumination device, comprising: an optical filter having an average transmittance in the wavelength range of the illumination light higher than an average transmittance in a visible light wavelength range other than the wavelength range of the illumination light; the wavelength range of the illumination light is a wavelength range of at least a wavelength 5 nm lower than a peak wavelength of the illumination light, and at most a wavelength 5 nm higher than the peak wavelength of the illumination light, An observation auxiliary device, wherein the peak wavelength of the illumination light is a wavelength at which a maximum radiant flux of the illumination light is obtained.

[0046]

[37] a wearing device that can be worn by an observer of the projection pattern; the mounting includes the optical filter, The observation assistance device according to

[36] , wherein when the observer wears the wearing device, the optical filter faces the observer's eyes.

[0047]

[38] The observation assistance device described in

[36] or

[37] , comprising an imaging device including the optical filter.

[0048]

[39] An observation assistance device that assists in observation of a pattern displayed on a surface, comprising: a display device that displays an image of the surface; A control device electrically connected to the display device, the controller detects the pattern in the image displayed on the display device and generates a display pattern related to the detected pattern; The display device displays the display pattern superimposed on the image, thereby providing an observation assistance device.

[0049]

[40] The observation assistance device described in

[39] , comprising an illumination device that projects the pattern onto a surface.

[0050] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings attached to this specification, the scale and the aspect ratio are appropriately changed and exaggerated from those of the actual objects for the convenience of illustration and understanding.

[0051] In this specification, multiple upper limit candidates and multiple lower limit candidates for a numerical range may be described in separate sentences. In this description, the numerical range may be formed by combining any one upper limit candidate and any one lower limit candidate. As an example, consider the description "Parameter B may be A1 or more, A2 or more, or A3 or more. Parameter B may be A4 or less, A5 or less, or A6 or less." In this example, the numerical range of parameter B may be A1 or more and A4 or less, A1 or more and A5 or less, A1 or more and A6 or less, A2 or more and A4 or less, A2 or more and A5 or less, A2 or more and A6 or less, A3 or more and A4 or less, A3 or more and A5 or less, or A3 or more and A6 or less.

[0052] In order to clarify the directional relationships between the drawings, some of the drawings use arrows to indicate a first direction D1, a second direction D2, and a third direction D3 as directions common to the drawings. The tip of the arrow is the first side of each of the directions D1, D2, and D3. An arrow pointing into the paper in a direction perpendicular to the paper surface of the drawing is indicated by a symbol with an x ​​in a circle, as shown in Figure 6, for example. An arrow pointing toward the paper in a direction perpendicular to the paper surface of the drawing is indicated by a symbol with a dot in a circle, as shown in Figure 10.

[0053] As used in this specification, terms that specify shapes or geometric conditions and their degrees, such as "parallel," "orthogonal," and "same," as well as values ​​of lengths and angles, are not limited to their strict meanings, but are interpreted to include a range within which similar functions can be expected.

[0054] The projection system 10 in this embodiment includes an illumination device 30 and an observation assistance device 100. The illumination device 30 projects a projection pattern 90 onto a projection surface 95. The observer 5 can observe the projection pattern 90 on the projection surface 95. In this embodiment described below, a device is devised to enable the observer 5 to clearly observe the projection pattern 90. Specifically, the projection system 10 includes an observation assistance device 100. The observation assistance device 100 includes an optical filter 120. The average transmittance of the optical filter 120 in the wavelength range of the illumination light emitted 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 wavelength range of the illumination light. By using the optical filter 120, the observer 5 can clearly observe the projection pattern 90.

[0055] An embodiment will now be described with reference to a specific example shown in the drawings.

[0056] The illumination device 30 projects illumination light onto an illuminated area 96 on a projection plane 95. The observer 5 recognizes the illuminated area 96 as a projection pattern 90. The projection pattern 90 has the same shape as the illuminated area 96.

[0057] The projection surface 95 onto which the illumination light from the illumination device 30 is irradiated is not particularly limited. In particular, according to this embodiment, the visibility of the projection pattern 90 is improved by the observation assistance device 100. Therefore, the projection surface 95 may be a surface onto which sunlight is irradiated as shown in Fig. 1. Examples of the projection surface 95 onto which the projection pattern 90 is projected include the ground of a road, a sidewalk, a playground, a park, etc., the surface of water such as the sea, and the outer wall surface, inner wall surface, passage, floor, ceiling, etc. of a building such as a school, a company, a building, a factory, a meeting hall, an auditorium, a gymnasium, a stadium, a venue, etc.

[0058] The projection pattern 90 and the illuminated area 96 are not particularly limited. The projection pattern 90 and the illuminated area 96 may include a single area. The projection pattern 90 and the illuminated area 96 may include multiple areas separated from each other. The projection pattern 90 may include one or more of a character, a picture, a geometric pattern, a symbol, a mark, an illustration, a character, and a pictogram. The projection pattern 90 may display information.

[0059] In the example shown in Fig. 1, the projection pattern 90 and the illuminated area 96 have a linear shape. The projection pattern 90 and the illuminated area 96 are linear and move away from the installation position of the illumination device 30. The projection pattern 90 and the illuminated area 96 are linear. The projection pattern 90 and the illuminated area 96 have a longitudinal direction in the first direction D1. The projection pattern 90 and the illuminated area 96 have a lateral direction in the second direction D2.

[0060] The illumination device 30 projects illumination light in a specific wavelength range onto the projection surface 95. The illumination light may be coherent light. Coherent light is light with a uniform wavelength and phase. The illumination light may include coherent light of a single wavelength. The illumination light may be green light with a wavelength of 520 nm. The illumination light may be green light with a wavelength of 530 nm. The illumination light may be red light with a wavelength of 635 nm. The illumination light may be red light with a wavelength of 638 nm. The illumination light may include coherent light of multiple wavelengths. The illumination light may be visible light.

[0061] The observation auxiliary device 100 includes an optical filter 120. The transmittance of the optical filter 120 is wavelength-dependent. The optical filter 120 selectively transmits illumination light emitted from the illumination device 30, among visible light. Visible light is light having a wavelength of 380 nm or more and 780 nm or less. More specifically, the average transmittance of the optical filter 120 in the wavelength range of the illumination light emitted from the illumination device 30 is higher than the average transmittance of the optical filter 120 in visible light wavelengths other than the wavelength range of the illumination light.

[0062] The average transmittance (%) is specified as the arithmetic mean value of the spectral transmittance for each 1 nm in the wavelength range of interest. The spectral transmittance (%) is the transmittance for a wavelength k (nm) in the wavelength range of interest, where k is a natural number. The wavelength range of the illumination light is specified as a wavelength range that is 5 nm lower than the peak wavelength of the illumination light and is 5 nm higher than the peak wavelength.

[0063] As an example, when the peak wavelength is 500 nm, the wavelength range of the illumination light is 495 nm to 505 nm. In this example, the "average transmittance in the wavelength range of the illumination light" is the arithmetic mean value of the spectral transmittance (%) for each of the wavelengths of 495 nm, 496 nm, 497 nm, 498 nm, 499 nm, 500 nm, 501 nm, 502 nm, 503 nm, 504 nm, and 505 nm. In this example, the "average transmittance of the optical filter 120 in the visible light wavelength range other than the wavelength range of the illumination light" is the arithmetic mean value of the spectral transmittance (%) measured at every 1 nm in the wavelength ranges of 380 nm to 494 nm and 506 nm to 780 nm.

[0064] Spectral transmittance is measured in accordance with JIS Z 8722:2009. The geometric condition e specified in JIS Z8722:2009 is used for measuring spectral transmittance. The measurement environment for measuring spectral transmittance is 23°C ± 2°C and 50% ± 5% relative humidity. The sample is placed in the measurement environment for 16 hours before starting the measurement. The light source is a D65 light source. The light source is turned on for 15 minutes before starting the measurement to stabilize the light source output.

[0065] The peak wavelength of the illumination light is the wavelength (nm) in the visible light range where the maximum radiant flux (W) of the illumination light is obtained. The peak wavelength of the illumination light is specified as a natural number (nm). The peak wavelength is measured using an optical spectrum analyzer. The peak wavelength is measured in accordance with the measurement method for peak emission wavelength described in JIS C 5941:1997. However, the illumination light to be measured is considered to be light emitted from a semiconductor laser that meets the standard. The measurement environment for measuring the peak wavelength is a temperature of 23°C ± 2°C, relative humidity of 50% ± 5%, and atmospheric pressure of 860hPa or higher and 1060hPa or lower. Before starting the measurement, turn on the illumination device for 15 minutes to stabilize the output of the illumination device.

[0066] 2A to 5, the projection system 10 and the observation auxiliary device 100 may include a wearing device 104 that can be worn by the observer 5. The wearing device 104 includes an optical filter 120. When the observer 5 wears the wearing device 104, the optical filter 120 faces the eyes of the observer 5. By the observer 5 observing the projection pattern 90 through the optical filter 120, the observer 5 can clearly observe the projection pattern 90 even in a bright environment, for example.

[0067] As shown in FIG. 2A, the wearing device 104 may be glasses. The wearing device 104 may be sunglasses. FIG. 2B shows a viewer 5 wearing the sunglasses of FIG. 2A. As shown in FIG. 2A and FIG. 2B, the wearing device 104 may include an optical filter 120, a frame 106, and a light-shielding wall portion 105. In the specific example shown in FIG. 2A and FIG. 2B, 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 that allows the viewer 5 to hold the frame body 106A. The frame body 106A holds one optical filter 120 facing the right eye and holds one optical filter 120 facing the left eye, as in normal glasses. The holding portion 106B is an ear hook portion. The light-shielding wall portion 105 is located around the optical filter 120. As shown in FIG. 2B , when the observer 5 is wearing the wearing device 104, the light-shielding wall portion 105 is located between the optical filter 120 and the observer 5. The light-shielding wall portion 105 has a visible light-shielding property. The light-shielding wall portion 105 may have a function of absorbing visible light. The light-shielding wall portion 105 may have a function of reflecting visible light. By providing the light-shielding wall portion 105, it is possible to prevent ambient light from entering between the eyes of the observer 5 and the optical filter 120 from the side.

[0068] FIG. 2C shows another specific example of the wearing equipment. As shown in FIG. 2C, the wearing equipment 104 may be goggles. The goggles may include a pair of optical filters 120. As shown in FIG. 2C, the goggles may include a single optical filter 120. In the example shown in FIG. 2C, when the observer 5 wears the wearing equipment 104, both eyes of the observer 5 face the single optical filter 120. The wearing equipment 104 shown in FIG. 2C includes the optical filter 120 and a frame 106. The frame 106 includes a frame main body 106A that holds the optical filter 120 and a holding portion 106B for fixing the frame main body 106A to the observer 5. The holding portion 106B may be a rubber that is held on the head of the observer 5. A pair of ends of the holding portion 106B are connected to each end of the frame main body 106A. The frame main body 106A also serves as the light-shielding wall portion 105. Frame body 106A, which is light-shielding wall portion 105, is connected to optical filter 120 from the periphery. When the observer wears mounting fixture 104, frame body 106A, which is light-shielding wall portion 105, is located between optical filter 120 and observer 5. Frame body 106A, which is light-shielding wall portion 105, can prevent ambient light from entering between optical filter 120 and observer 5 from the side.

[0069] As shown in FIG. 3A and FIG. 3B, the wearing device 104 may be goggles. In the specific example shown in FIG. 3A and FIG. 3B, the optical filter 120 curved along the face of the observer 5 directly contacts the face of the observer 5. The holding parts 106B are connected to both ends of the optical filter 120. The pair of holding parts 106B may be rubber or string. As shown in FIG. 3B, each holding part 106B may be hung on the corresponding ear. In the example shown in FIG. 3B, when the wearing device 104 is worn, the periphery of the optical filter 120 contacts the face of the observer 5. This makes it possible to suppress ambient light from entering between the optical filter 120 and the observer 5 from the side.

[0070] As shown in FIG. 4, the wearing tool 104 includes an optical filter 120 and a wearing tool main body 107 to be worn on the head. The wearing tool main body 107 may be a helmet. The wearing tool main body 107 may be a hat. The optical filter 120 may be goggles. The optical filter 120 is attached to the wearing tool main body 107. When the observer 5 wears the wearing tool main body 107 on his / her head, the optical filter 120 faces the eyes of the observer 5. In the illustrated example, the periphery of the optical filter 120 contacts the face of the observer 5, similarly to the example of FIG. 3B. This makes it possible to suppress ambient light from entering between the optical filter 120 and the observer 5 from the side. The optical filter 120 may be detachable from the wearing tool main body 107.

[0071] 5, the wearing tool 104 may be a contact lens. The wearing tool 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 viewer 5 wears the contact lens on his / her 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, it is possible to suppress ambient light from entering between the optical filter 120 and the viewer 5 from the side.

[0072] As shown in FIG. 15, the optical filter 120 may be included in a windshield 81 of a moving body 80. The moving body 80 is a movable device. The moving body 80 may be a car, a train, a ship, an airplane, or a drone. The moving body 80 may be a vehicle in which a person can ride, or may not be a vehicle in which a person can ride. The windshield 81 may be installed in an opening such as a window of the moving body 80. The windshield 81 may function as a windbreak. The windshield 81 may be a partition member 82 such as a window member that partitions the inside of the moving body 80 from the outside.

[0073] The observer 5 may be able to observe the outside of the moving body 80 through the windshield 81. In this example, the observer 5 can clearly observe the projection pattern 90, for example, even in a bright environment. When the incidence of ambient light into the moving body 80 from other openings of the moving body 80 is suppressed, the observer 5 can more clearly observe the projection pattern 90. As shown in FIG. 15, the observer 5 may operate the moving body 80.

[0074] As shown in FIG. 6, the projection system 10 and the observation assistance device 100 may include an imaging device 101. The imaging device 101 includes an optical filter 120 and an imaging element 101a. Light transmitted through the optical filter 120 is incident on the imaging element 101a. The imaging device 101 captures an image of a projection surface 95 including an illuminated region 96. The observer 5 observes the projection surface 95 captured by the imaging device 101. This allows the observer 5 to clearly observe the projection pattern 90 even in a bright environment, for example.

[0075] 6, the projection system 10 and the observation assistance device 100 may include a display device 102 electrically connected to an imaging device 101. The display device 102 displays an image captured by the imaging device 101. The observer 5 can clearly observe the projection pattern 90 displayed on the display device 102. The display device 102 may be a display device such as a liquid crystal display, a plasma display, an organic EL display, or a projection display device. The display device 102 may include a touch panel sensor that functions as an input unit.

[0076] When performing work by simply observing the captured projection surface 95 from the display device 102, the illumination light does not need to be limited to the visible light range; for example, the imaging device 101 may be an infrared camera, the illumination light may be infrared light, and the central wavelength of the optical filter may be in the infrared range.

[0077] As shown in Fig. 16, the display device 102 may include a wearing tool 102B and a display element 102A. The observer 5 can wear the wearing tool 102B. The wearing tool 102B holds the display element 102A. When the observer 5 wears the wearing tool 102B, the display element 102A faces the eyes of the observer 5. When the observer 5 wears the wearing tool 102B, the observer 5 can view an image displayed on the display element 102A. Such a display device 102 is a wearable display device.

[0078] The display device 102 may be VR (Virtual Reality) glasses, AR (Argumented Reality) glasses, or a head-mounted display. In the wearable display device 102, the observer 5 may be able to observe through the wearing equipment 102B. In this example, the total light transmittance of the wearing equipment 102B may be 1% or more, 10% or more, 30% or more, 50% or more, 60% or more, 70% or more, or 80% or more.

[0079] When performing work by simply observing images from an imaging device or sensor built into the display device 102, the illumination light does not need to be limited to the visible light range; for example, if the imaging device built into the display device 102 is an infrared camera or infrared sensor, the illumination light may be infrared light and the central wavelength of the optical filter may be in the infrared range.

[0080] There is no particular upper limit set for the total light transmittance of the wearing equipment 102B. The total light transmittance of the wearing equipment 102B may be, for example, 100% or less, or may be less than 100%.

[0081] A D65 light source is used to measure the total light transmittance (%). The wavelength range of light used to measure the total light transmittance (%) is 380 nm or more and 780 nm or less. Before measuring the total light transmittance of the display element 102A, the light source is turned on for 15 minutes to stabilize the output of the light source. The angle of incidence on the sample when measuring the total light transmittance is 0°. The measurement environment when measuring the total light transmittance is a temperature of 23°C ± 2°C and a relative humidity of 50% ± 5%. The sample is placed in the measurement environment for 16 hours before starting the measurement. Other measurement conditions when measuring the total light transmittance are in accordance with JIS K7361-1:1997.

[0082] FIG. 7A shows an example of a transmission spectrum of the optical filter 120 in the visible light range. The optical filter 120 may selectively transmit only the illumination light emitted from the illumination device 30. In this embodiment, the average transmittance of the optical filter 120 in the wavelength range of the illumination light is higher than the average transmittance of the optical filter 120 in the visible light wavelength range other than the wavelength range of the illumination light. This allows the observer 5 to clearly observe the projection pattern 90 on the projection surface 95 through the optical filter 120 even if the amount of ambient light such as sunlight irradiated on the projection surface 95 is large. In order to expect the function of this optical filter 120, the wavelength range of the illumination light emitted from the illumination device 30 may be sufficiently narrow. From this point of view, the illumination light may be coherent light. The illumination light may be laser light of a specific wavelength.

[0083] A lower limit may be set for the average transmittance of the optical filter 120 in the wavelength range of the illumination light. By setting a lower limit for this average transmittance, the illumination light can pass through the optical filter 120 with high transmittance. The observer 5 can clearly observe the projection pattern 90 through the optical filter 120. The average transmittance of the optical filter 120 in the wavelength range of the illumination light may be 50% or more, 70% or more, or 80% or more.

[0084] There is no particular upper limit set for the average transmittance of the optical filter 120 in the wavelength range of the illumination light. The average transmittance of the optical filter 120 in the wavelength range of the illumination light may be 100% or less, or may be less than 100%. The average transmittance of the optical filter 120 in the wavelength range of the illumination light may be 50% or more and 100% or less.

[0085] Similarly, a lower limit may be set for the maximum spectral transmittance of the optical filter 120 in the visible light range. By setting a lower limit for the maximum spectral transmittance, the illumination light can pass through the optical filter 120 with high transmittance. The observer 5 can clearly observe the projection pattern 90 through the optical filter 120. The maximum spectral 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 when the illumination light is of a single wavelength, the average transmittance (%) of the optical filter 120 in the wavelength range of the illumination light may be the same as the maximum spectral transmittance (%) of the optical filter 120 in the visible light range.

[0086] There is no particular upper limit set for the maximum spectral transmittance in the visible light range of the optical filter 120. The maximum spectral transmittance in the visible light range of the optical filter 120 may be 100% or less, or may be less than 100%. The maximum spectral transmittance in the visible light range of the optical filter 120 may be 50% or more and 100% or less.

[0087] The full width at half maximum FWHM of the spectral transmittance of the optical filter means the width (nm) of the wavelength range where the transmittance is more than half the maximum transmittance in the wavelength distribution of the spectral transmittance. An upper limit may be set to the full width at half maximum FWHM of the spectral transmittance of the optical filter. By setting an upper limit to the full width at half maximum FWHM, illumination light in a specific wavelength range can be transmitted through the optical filter 120 in a concentrated manner. When the wavelength range of the illumination light is narrow, for example, when the illumination light is coherent light or when the illumination light is laser light, the illumination light can be transmitted through the optical filter 120 in a concentrated manner. At the same time, the transmission of environmental light such as sunlight through the optical filter 120 can be suppressed. Therefore, when the projection pattern 90 is observed through the optical filter 120, the environmental light can be weakened to emphasize the projection pattern 90. That is, the contrast of the projection pattern 90 can be improved. This allows the projection pattern 90 to be clearly observed. From this viewpoint, the full width at half maximum FWHM of the spectral transmittance of the optical filter may be 15 nm or less, 3 nm or less, or 1 nm or less.

[0088] The lower limit of the full width at half maximum FWHM of the spectral transmittance of the optical filter is not particularly set. The full width at half maximum FWHM of the spectral transmittance of the optical filter may be greater than 0 nm. The full width at half maximum FWHM of the spectral transmittance of the optical filter may be 0 nm or more and 15 nm or less.

[0089] An upper limit may be set on the average transmittance of the optical filter 120 in a visible light wavelength range other than the wavelength range of the illumination light. By setting an upper limit on this average transmittance, it is possible to suppress the transmission of environmental light such as sunlight through the optical filter 120. This improves the contrast of the projection pattern 90, allowing the projection pattern 90 to be clearly observed. The average transmittance of the optical filter 120 in a visible light wavelength range other than the wavelength range of the illumination light may be 1% or less, 0.1% or less, or 0.01% or less.

[0090] A lower limit may be set for the average transmittance of the optical filter 120 in a visible light wavelength range other than the wavelength range of the illumination light. By setting a lower limit for this average transmittance, even when the amount of ambient light is low, such as at night, the relative position of the projection pattern 90 with respect to the surrounding environment can be grasped through the optical filter 120. This allows the projection pattern 90 to be clearly observed through the optical filter 120 in both cases, while the optical filter 120 is handled in the same way when the projection surface 95 is bright and when the projection surface 95 is dark. The average transmittance of the optical filter 120 in a visible light wavelength range other than the wavelength range of the illumination light may be 0.001% or more, 0.005% or more, or 0.01% or more.

[0091] The average transmittance of the optical filter 120 in the visible light wavelength range other than the wavelength range of the illumination light may be 0.001% or more and 1% or less.

[0092] An upper limit may be set for the average transmittance of the optical filter 120 in a visible light wavelength range other than the 30 nm wavelength range centered on the peak wavelength of the illumination light. By setting an upper limit for this average transmittance, when the wavelength range of the illumination light is narrow, for example, when the illumination light is coherent light or when the illumination light is laser light, the illumination light can be transmitted through the optical filter 120 in a concentrated manner while suppressing the transmission of environmental light such as sunlight through the optical filter 120. This allows illumination light in a specific wavelength range to be transmitted through the optical filter 120 in a concentrated manner. The average transmittance of the optical filter 120 in a visible light wavelength range other than the 30 nm wavelength range centered on the peak wavelength of the illumination light may be 1% or less, 0.1% or less, or 0.01% or less.

[0093] A lower limit may be set for the average transmittance of the optical filter 120 in a visible light wavelength range other than the 30 nm wavelength range centered on the peak wavelength of the illumination light. By setting a lower limit for this average transmittance, even when the amount of ambient light is low, such as at night, the relative position of the projection pattern 90 with respect to the surrounding environment can be grasped through the optical filter 120. This allows the projection pattern 90 to be clearly observed through the optical filter 120 in both cases, while the optical filter 120 is handled in the same way when the projection surface 95 is bright and when the projection surface 95 is dark. The average transmittance of the optical filter 120 in a visible light wavelength range other than the 30 nm wavelength range centered on the peak wavelength of the illumination light may be 0.001% or more, 0.005% or more, or 0.01% or more.

[0094] The average transmittance of the optical filter 120 in the visible light wavelength range other than the 30 nm wavelength range centered on the peak wavelength of the illumination light may be 0.001% or more and 1% or less.

[0095] As described above, when multiple upper limit candidates and multiple lower limit candidates are given for a numerical range of transmittance, full width at half maximum, illuminance, etc., the numerical range may be constructed by combining any one of the upper limit candidate and any one of the lower limit candidate.

[0096] There are no particular limitations on the optical filter 120 as long as it has wavelength selective transmission properties. The optical filter 120 may include a dielectric multilayer film 122. The dielectric multilayer film 122 is advantageous in that it allows a high degree of freedom in designing the transmission characteristics.

[0097] Fig. 7B is a cross-sectional view showing an example of a layer structure of optical filter 120. Optical filter 120 shown in Fig. 7B includes a first protective layer, a second protective layer, and a dielectric multilayer film 122 located between first protective layer 121A and second protective layer 121B.

[0098] The dielectric multilayer film 122 may include low-refractive index layers 122a and high-refractive index layers 122b that are alternately stacked. 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.

[0099] The dielectric multilayer film including an inorganic layer can be obtained by alternately laminating high refractive index inorganic layers and low refractive index inorganic layers by, for example, a CVD method, a sputtering method, a vacuum deposition method, or a wet coating method. The thickness of the multilayer film of inorganic compounds may be 0.5 μm or more and 10 μm or less. The refractive index of the inorganic compound included in the high refractive index inorganic layer may be 1.7 or more and 2.5 or less. Examples of the inorganic compound included in the high refractive index inorganic layer include those containing titanium oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide, and indium oxide as main components, and containing small amounts of titanium oxide, tin oxide, cerium oxide, and the like. The refractive index of the inorganic compound included in the low refractive index inorganic layer may be 1.2 or more and 1.6 or less. Examples of the inorganic compound included in the low refractive index inorganic layer include silica, alumina, lanthanum fluoride, magnesium fluoride, and sodium aluminum hexafluoride.

[0100] The dielectric multilayer film 122 including the resin layer may include multiple layers of thermoplastic resin or thermosetting resin. Various additives, such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, viscosity reducing agents, heat stabilizers, lubricants, infrared absorbing agents, ultraviolet absorbing agents, and doping agents for adjusting the refractive index, may be added to the resin layer. The in-plane average refractive index difference between the high refractive index resin layer and the low refractive index resin layer may be 0.03 or more, 0.05 or more, or 0.1 or more.

[0101] The number of high-refractive index resin layers and low-refractive index resin layers stacked is adjusted according to the reflection and transmission characteristics required for the optical filter 120. For example, 30 or more high-refractive index resin layers and 200 or more low-refractive index resin layers may be stacked alternately. The total number of high-refractive index resin layers and low-refractive index resin layers stacked may be, for example, 600 or more.

[0102] Examples of methods for producing the resin multilayer film that constitutes the dielectric multilayer film include a co-extrusion method, etc. Specifically, reference can be made to the method for producing a laminated film described in JP-A-2008-200861.

[0103] The first protective layer 121A and the second protective layer 121B may contain polyethylene terephthalate or polyethylene naphthalate. The thickness of the first protective layer and the second protective layer may be 3 μm or more, or 5 μm or more.

[0104] The dielectric multilayer film 122 transmits light in a specific wavelength range and reflects light in a wavelength range other than the specific wavelength range. The ambient light that passes through the optical filter 120 and enters the space between the eye of the observer 5 and the optical filter 120 travels toward the eye of the observer. On the other hand, the ambient light that enters the space between the eye of the observer 5 and the optical filter 120 from the side may be incident on the surface of the optical filter 120 facing the observer 5 and reflected with a high reflectance. This reflection makes the surface of the optical filter 120 facing the observer 5 mirror-like, reducing the visibility of the projection pattern 90. As described above, the optical filter 120 may contact the face of the observer 5 to suppress the incidence of ambient light such as sunlight into the space between the eye of the observer 5 and the optical filter 120. The light-shielding wall portion 105 may be used to suppress the incidence of ambient light such as sunlight from the side into the space between the eye of the observer 5 and the optical filter 120. The average transmittance of the light-shielding wall portion 105 in the visible light wavelength range may be 0%.

[0105] Next, the operation of the projection system 10 and the observation auxiliary device 100 when used will be described.

[0106] As shown in Fig. 1, the illumination device 30 emits illumination light. The illumination light is irradiated onto an illuminated area 96 on a projection surface 95. An observer 5 can observe a projection pattern 90 on the projection surface 95. The projection pattern 90 has the same shape as the illuminated area 96. The projection pattern 90 may display various information.

[0107] For example, the projection pattern 90 may show the work target area to the observer 5 performing the work. The observer 5, who is a worker, may use the projection pattern 90 when drawing, for example, a white line or an orange line on a road, a sidewalk, or a parking lot. Without being limited to this example, the projection pattern 90 may display a direction such as an arrow. According to this example, the projection pattern 90 may display a travel route or an evacuation route. Furthermore, the projection pattern 90 may be letters, numbers, or the like. According to this example, necessary information can be directly shown to the observer 5. Furthermore, the projection pattern 90 may be an advertisement.

[0108] However, the contrast of the projection pattern 90X decreases depending on the ambient light in the environment in which the illumination device 30X is used. In this case, the observer 5X cannot clearly observe the projection pattern 90X on the projection surface 95X. As shown in FIG. 25, when the amount of ambient light such as sunlight is large, the illuminance (lx) on the projection surface 95X increases. The contrast of the projection pattern 90X projected on this projection surface 95X decreases significantly. The observer 5X cannot accurately observe the shape of the projection pattern 90X. Furthermore, the observer 5X cannot even notice the existence of the projection pattern 90X on the projection surface 95X.

[0109] In this embodiment, the projection system 10 includes an observation auxiliary device 100 in addition to the illumination device 30. The observation auxiliary device 100 includes an optical filter 120. The average transmittance of the optical filter 120 in the wavelength range of the illumination light emitted 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 wavelength range of the illumination light. By observing the projection pattern 90 through this optical filter 120, it is possible to suppress the brightness of the environmental light while maintaining the brightness of the projection pattern 90. This improves the contrast of the projection pattern 90, and allows the projection pattern 90 to be clearly observed.

[0110] In the example shown in Figs. 2 to 5, the observation auxiliary device 100 includes a wearing tool 104. When the observer 5 wears the wearing tool 104, the optical filter 120 faces the eyes of the observer 5. That is, by wearing the wearing tool 104, the observer 5 can observe the projection pattern 90 and the projection surface 95 through the optical filter 120. Since the optical filter 120 does not need to be held by the hands, the observer 5 can use both hands freely while clearly observing the projection pattern 90. For example, the observer 5 can stably perform work while clearly observing the projection pattern 90.

[0111] The wearing equipment 104 shown in FIGS. 2A to 2C may be glasses, sunglasses, or goggles. The illustrated wearing equipment 104 includes a light-shielding wall portion 105 located around the optical filter 120. When the observer 5 wears the wearing equipment 104, the light-shielding wall portion 105 is located between the optical filter 120 and the observer 5. The light-shielding wall portion 105 blocks the ambient light, thereby preventing the ambient light from entering the space between the optical filter 120 and the observer 5 from the side. Therefore, when a reflective optical filter 120 is used, it is possible to prevent the visibility of the projection pattern 90 from decreasing due to the reflection of the ambient light on the optical filter 120.

[0112] The wearing tool 104 shown in Fig. 5 is a contact lens. In this example, the observer 5 does not need to hold the optical filter 120 with his / her hands. Therefore, the observer 5 can use both hands freely while observing the projection pattern 90. In addition, the contact lens body 108 is located between the optical filter 120 and the eyes of the observer 5. Therefore, it is possible to suppress the incidence and reflection of ambient light on the surface of the optical filter 120 facing the eyes of the observer 5.

[0113] 15, the optical filter 120 constitutes a windshield 81 of the moving body 80. In this example, the observer 5 does not need to hold the optical filter 120 by hand. In the example shown in FIG. 15, the observer 5 boards the moving body 80 and operates the moving body 80.

[0114] In the example shown in FIG. 6, the observation assistance device 100 includes an imaging device 101. The imaging device 101 captures the projection pattern 90 through an optical filter 120. The imaging device 101 captures the projection pattern 90 and its surroundings by significantly reducing ambient light by the optical filter 120. Therefore, by using the imaging device 101, the projection pattern 90 can be clearly observed. In the example shown in FIG. 6, the observation assistance device 100 includes a display device 102 electrically connected to the imaging device 101. The display device 102 displays an image captured by the imaging device 101, that is, the projection pattern 90. The display device 102 displays the projection pattern 90 with improved contrast. The observer 5 can clearly observe the projection pattern 90 displayed by the display device 102.

[0115] As described above, the average transmittance of the optical filter 120 in the wavelength range of the illumination light emitted 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 illumination light emitted from the illumination device 30 may include a wavelength at which the transmittance of the optical filter 120 is maximum. According to these examples, when the projection pattern 90 is observed through the optical filter 120, the brightness of the projection pattern 90 can be maintained. This allows the projection pattern 90 to be clearly observed.

[0116] The average transmittance of the optical filter 120 in a visible light wavelength range other than the wavelength range of the illumination light emitted from the illumination 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 a visible light wavelength range other than the 30 nm wavelength range centered on the peak wavelength of the illumination light emitted from the illumination 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 environmental light such as sunlight through the optical filter 120. This improves the contrast of the projection pattern 90, allowing the projection pattern 90 to be clearly observed.

[0117] The full width at half maximum FWHM of the spectral transmittance of the optical filter may be 15 nm or less, 3 nm or less, or 1 nm or less. According to this example, when observed through the optical filter 120, the brightness of the projected pattern 90 can be maintained while the ambient light can be reduced. This improves the contrast of the projected pattern 90, allowing the projected pattern 90 to be clearly observed. The full width at half maximum FWHM of the spectral transmittance of the optical filter may include the entire wavelength range of the illumination light emitted from the illumination device 30.

[0118] The average transmittance of the optical filter 120 in a visible light wavelength range other than the wavelength range of the illumination light emitted from the illumination 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 a visible light wavelength range other than the 30 nm wavelength range centered on the peak wavelength of the illumination light emitted from the illumination 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 projection pattern 90 to the surrounding environment can be grasped through the optical filter 120. For example, the projection pattern 90 can be clearly observed in both cases, while the optical filter 120 is handled in the same way between the case where the projection surface 95 is bright and the case where the projection surface 95 is dark.

[0119] A lower limit may be set for the maximum illuminance of the projection pattern 90 projected on the projection surface 95. Here, the "illuminance of the projection pattern 90 projected on the projection surface 95" refers to the illuminance on the projection surface 95 caused only by the illumination light emitted from the illumination device 30. Therefore, the difference between the illuminance measured at a certain position on the projection surface 95 when the projection pattern 90 is projected and the illuminance measured at the same position on the projection surface 95 when the projection pattern 90 is not projected is the "illuminance of the projection pattern 90 projected on the projection surface 95". By setting a lower limit for the maximum illuminance of the projection pattern 90, the projection pattern 90 can be observed brightly and clearly. The maximum illuminance of the projection pattern 90 projected on the projection surface 95 may be 1 lx or more, 0.1 lx or more, or 0.01 lx or more.

[0120] An upper limit may be set for the maximum illuminance of the projection pattern 90 projected onto the projection surface 95. If the illuminance of the projection pattern 90 is set too high, the visibility of the projection pattern 90 is not effectively improved and energy efficiency deteriorates. From this point of view, the maximum illuminance of the projection pattern 90 projected onto the projection surface 95 may be 10,000 lx or less, 1,000 lx or less, 100 lx or less, or 10 lx or less.

[0121] The maximum value of the illuminance of the projection pattern 90 projected on the projection surface 95 is defined as illuminance LX (lx). The illuminance due to the ambient light at the position on the projection surface 95 where the illuminance LX is obtained is defined as illuminance LY (lx). The illuminance LY is measured on the projection surface 95 in a state where the projection pattern 90 is not projected. The average transmittance of the optical filter 120 in the wavelength range of the illumination light emitted from the illumination device 30 is defined as transmittance TX (%). The average transmittance of the optical filter 120 in the visible light wavelength range other than the wavelength range of 30 nm centered on the peak wavelength of the illumination light emitted from the illumination device 30 is defined as transmittance TY (%). In this case, the illuminance LX, the illuminance LY, the transmittance TX, and the transmittance TY may satisfy the following relationship. 0.001≦(LX TX) / (LY TY) According to this example, the contrast of the projection pattern 90 is improved, and the projection pattern 90 can be clearly observed. From the viewpoint of improving the visibility of the projection pattern 90, "(LX·TX) / (LY·TY)" may be 0.01 or more, or may be 0.1 or more.

[0122] The illuminance LX, the illuminance LY, the transmittance TX, and the transmittance TY may satisfy the following relationship. (LX TX) / (LY TY) ≦ 10 According to this example, it is possible to prevent the surroundings of the projection pattern 90 from becoming too dark. That is, even when the amount of ambient light is low, the relative position of the projection pattern 90 with respect to the surrounding environment can be grasped through the optical filter 120. For example, while the optical filter 120 is handled in the same manner in both cases, when the projection surface 95 is bright and when the projection surface 95 is dark, the projection pattern 90 can be clearly observed in both cases.

[0123] The illuminance is measured using a Konica Minolta CL-500A spectroradiometer in accordance with JIS (JIS C 1609-1:2006). The measurement wavelength is 380 nm or more and 780 nm or less. The measurement wavelength interval is 1 nm. The illuminance meter is placed on the projection surface 95 and measurements are taken.

[0124] Next, a specific configuration of the illumination device 30 will be described.

[0125] As shown in FIG. 8, 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 emits illumination light. The light source 40 is not particularly limited. The light source 40 may emit coherent light with a constant wavelength and phase. The coherent light emitted from the light source 40 has excellent linearity. Therefore, the light source 40 is suitable for the illumination device 30 that illuminates a distant object. Various types of light sources can be used as the light source 40. A laser light source that oscillates a laser light may be used as the light source 40. An example of the laser light source is a semiconductor laser light source. In the example shown in FIG. 8, the light source 40 includes a single coherent light source. Therefore, in the example shown in FIG. 8, the illuminated area 96 is illuminated with coherent light of a color corresponding to the wavelength range of the coherent light oscillated from the light source 40. In the following, an example in which the light source 40 emits coherent light will be described.

[0126] 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 illumination light in a cross section perpendicular to the optical axis or the three-dimensional shape of the illumination coherent light. The shaping optical system 45 may expand the cross-sectional area of ​​the coherent light in a cross section perpendicular to the optical axis of the coherent light.

[0127] In the example shown in FIG. 8, 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 FIG. 8, 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 diverging beam. The second lens 47 shapes the diverging beam generated by the first lens 46 into a parallel beam. In this example, the second lens 47 functions as a collimating lens.

[0128] The diffractive optical element 50 changes the traveling direction of the coherent light from the light source 40. The coherent light diffracted by the diffractive optical element 50 is irradiated onto an illuminated area 96 on a projection surface 95. The diffractive optical element 50 diffracts the coherent light from the light source 40 and directs it towards an illuminated area 96 on the projection surface 95. As a result, the projection surface 95 is irradiated with the light diffracted by the diffractive optical element 50. A projection pattern 90 corresponding to the diffraction pattern by the diffractive optical element 50 is projected onto the projection surface 95.

[0129] The diffractive optical element 50 may be a hologram element. By using a hologram element as the diffractive optical element 50, it becomes easier to design the diffraction characteristics of the diffractive optical element 50. It is relatively easy to design a hologram element that can irradiate light only over the entirety of a desired area that has a predetermined position, contour shape, size, and orientation on the projection surface 95. The area on the projection surface 95 that is irradiated with the coherent light becomes the illuminated area 96.

[0130] When designing the diffractive optical element 50, the illuminated area 96 is set in real space at a predetermined position with respect 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 96 on the projection plane 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 96 on the projection plane 95 can be arbitrarily adjusted. Therefore, when designing the diffractive optical element 50, the position, contour shape, size and orientation of the illuminated area 96 on the projection plane 95 are first determined. Next, the diffraction characteristics of the diffractive optical element 50 are adjusted so that the determined illuminated area 96 can be irradiated with light in its entirety.

[0131] The diffractive optical element 50 may be produced as a computer generated hologram (CGH). A computer generated hologram is produced by calculating a structure having any diffraction characteristics on a computer. Therefore, by adopting 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 an optical system, and to record interference fringes on a hologram recording material by exposure. The illumination device 30 is assumed to irradiate an illumination area 96 having a predetermined contour shape, size, and orientation at a predetermined position relative to the illumination device 30 with illumination light. By inputting information about the illumination area 96 as parameters into a computer, a structure having diffraction characteristics capable of projecting diffracted light onto the illumination area 96, such as an uneven surface, can be specified by computer calculation. By forming the specified structure, for example, by resin molding, the diffractive optical element 50 as a computer generated hologram can be produced at low cost by a simple procedure.

[0132] The diffractive optical element 50 may be designed using, for example, an iterative Fourier transform method. When the iterative Fourier transform method is used, processing may be performed on the premise that the illuminated region 96 is located far away from the diffractive optical element 50, and the projection pattern 90 projected onto the projection plane 95 may be a Fraunhofer diffraction image. Therefore, the projection plane 95 may be non-parallel to the diffractive surface of the diffractive optical element 50.

[0133] As shown in FIG. 9, the diffractive optical element 50 may include a plurality of element diffractive optical elements 55. Each element diffractive optical element 55 may be, for example, a hologram element, and may be configured in the same manner as the diffractive optical element 50 described above. In the example shown in FIG. 9, the coherent light diffracted by the plurality of element diffractive optical elements 55 is irradiated onto the same illuminated region 96. That is, the light diffracted by each element diffractive optical element 55 is irradiated onto the entire illuminated region 96 on the projection surface 95. According to such a diffractive optical element 50, the light directed toward each position in the illuminated region 96 can be dispersed and emitted from the plurality of element diffractive optical elements 55 included in the diffractive optical element 50. This prevents each position on the diffractive optical element 50 from becoming too bright, and improves laser safety.

[0134] The element diffractive optical elements 55 may be configured to have the same diffraction characteristics as each other. However, in order to realize irradiation with higher accuracy, each element diffractive optical element 55 may be given a diffraction characteristic that is designed separately according to the arrangement position of the element diffractive optical element 55 in the diffractive optical element 50. According to this example, the diffraction characteristic of each element diffractive optical element 55 is adjusted according to the difference in arrangement with other element diffractive optical elements 55, so that the diffracted light of light can be directed with high accuracy only to the entire illuminated region 96 on the projection surface 95.

[0135] By the way, the illumination device 30 having the light source 40 that emits coherent light and the diffractive optical element 50 that diffracts the coherent light can illuminate a large illuminated area 96 on the projection surface 95 or an illuminated area 96 that extends to a position far away from the illumination device 30. That is, a long and narrow projection pattern 90 can be projected onto the projection surface 95. At this time, the incidence angle α of the coherent light at each position in the illuminated area 96 varies greatly. The incidence angle α at the illuminated area 96 far away from the illumination device 30 becomes very large, for example, close to 90°. The diffractive surface of the diffractive optical element 50 forms a large angle with the projection surface 95 and the illuminated area 96. Here, the incidence angle α at the illuminated area 96 is the angle that the traveling direction of the illumination light makes with the normal direction ND of the illuminated area 96. In the illustrated example, the normal direction ND is parallel to a third direction D3 that is perpendicular to both the first direction D1 and the second direction D2.

[0136] 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 illuminated area 96 of a desired shape. Therefore, the illuminated area 96 can be set, for example, at a position far away from the illumination device 30 or at a position where the incidence angle α of the coherent light becomes large, without being strongly restricted by the relative position with the illumination device 30. In other words, the degree of freedom in setting the projection pattern 90 and the projection surface 95 can be greatly improved. As a result, the illuminated area 96 can be irradiated with coherent light with high accuracy. The projection pattern 90 can be accurately projected onto the projection surface 95.

[0137] As an example, the diffractive optical element 50 made of a computer-generated hologram can adjust the traveling direction of coherent light incident from a certain direction in the angle space with an accuracy of ±0.01°. By using such a diffractive optical element 50, it is possible to highly accurately illuminate an illuminated area 96 located at a distance of 1 m or more and 120 m or less from the diffractive optical element 50, or an illuminated area 96 where the incidence angle α of the coherent light to the illuminated area 96 is at least 30° or more and at most 89.99° or less. Therefore, the illumination device 30 can highly accurately irradiate the illuminated area 96 located on the projection surface 95 with coherent light. This makes the edges of the projection pattern 90 clear, and the operator can observe the projection pattern 90 located far away.

[0138] FIG. 10 shows a specific configuration example of the illumination device 30. The illumination device 30 shown in FIG. 10 is portable. That is, the illumination device 30 shown in FIG. 10 can be carried by an operator without using any special means. The illumination device 30 has a casing 70. In the illumination device 30 shown in FIG. 10, 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 cannot be removed 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 the projection pattern 90 to be stably projected at a position on the projection surface 95 that is in a predetermined relative positional relationship with the illumination device 30 with high accuracy. Moreover, the light source 40, the shaping optical system 45, and the diffractive optical element 50 are prevented from being displaced from their predetermined positions, thereby improving laser safety.

[0139] In the example shown in FIG. 10, the shaping optical system 45 includes a first lens 46, a second lens 47, and a third lens 48. The casing 70 includes 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 cylindrical with one end closed. The light source 40 is fixed to the closed end of the cylindrical portion 71. The inner dimension of the cylindrical portion 71 changes via a step portion 71a. The inner 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 attached to each of the two step portions 71a. A spacing ring 73 that can control the lens distance with high precision is provided in the cylindrical portion 71. The spacing ring 73 is arranged between the first lens 46 and the second lens 47. The spacing ring 73 is arranged between the second lens 47 and the third lens 48. In addition, a spacing ring 73 is disposed between the lid portion 72 and the third lens 48. The spacing ring 73 suppresses the relative positional deviation of each lens due to vibrations or impacts that may be applied to the lighting device 30. The spacing ring 73 may be, for example, a ring-shaped or cylindrical member. Metals such as aluminum or resins may be used as the spacing ring 73. Inorganic materials such as glass fiber may be mixed into the resin to reduce the thermal expansion coefficient. The spacing ring 73 can suppress deviation in the parallelism of the collimated light due to vibrations or impacts applied to the lighting device 30. In other words, it can suppress blurring of the projection pattern 90 on the projection surface 95. This makes it possible to maintain high visibility of the projection pattern 90.

[0140] In order to maintain constant relative positions of the light source 40, the shaping optical system 45, the diffractive optical element 50, etc., 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 an adhesive in combination with fixing by fitting.

[0141] For example, a spacer may be used to finely adjust the relative positions of the light source 40, the shaping optical system 45, the diffractive optical element 50, etc. A thin metal plate may be used as the spacer. The spacer may be used in combination with the spacer ring 73 or an adhesive.

[0142] Also, 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 fine adjustment of the arrangement. The position adjustment holder may allow fine adjustment of the positions 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 the position adjustment holder, the adjustment part such as a screw may be fixed with an adhesive or the like after adjustment of the positions of the components is completed. Also, the position adjustment holder may be used in combination with the spacing ring 73 described above or other members for maintaining the relative positions of the finely adjusted components.

[0143] The casing 70 may be made non-disassembleable, and the relative positions of the components, such as the light source 40, the shaping optical system 45, and the diffractive optical element 50, may be maintained. For example, the relative positions of the components positioned by the manufacturer of the illumination device 30 may be maintained. For example, an adhesive may be applied to the screw-fastened or fitted portions of the casing 70 to make the casing 70 non-disassembleable.

[0144] In the example shown in Fig. 10, 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.

[0145] The lighting device 30 may be configured to receive power from an external power source. For example, a connector for electrically connecting to an external power source may be provided on the casing. In this example, the lighting device 30 may include a primary battery or a secondary battery, or may not include a primary battery or a secondary battery. The lighting device 30 that does not include a primary battery or a secondary battery is lightweight and therefore has excellent resistance to vibration and impact.

[0146] The lighting device 30 and the casing 70 may be waterproof. To impart waterproofing to the lighting device 30, waterproof members such as rubber or packing may be provided at the joints and fittings of the casing 70.

[0147] The lighting device 30 may have a temperature adjustment mechanism. The temperature adjustment mechanism may maintain the light source 40 and the circuit 75 at a temperature within a predetermined range. The temperature adjustment mechanism may heat or cool the light source 40 and the circuit 75. The temperature adjustment mechanism may be installed inside the casing 70. Examples of the temperature adjustment mechanism include a fan, a heater, and a cooler. The temperature adjustment mechanism may utilize a heating wire, a Peltier element, or the like.

[0148] As shown in FIG. 11, the illumination device 30 may include a scanning device 60. The illumination device 30 shown in FIG. 11 includes 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 the coherent light is supplied to the diffractive optical element 50 and to control the distribution of the coherent light to the plurality of diffractive optical elements 50A to 50C. The scanning device 60 may be configured using various components that can change the optical path by utilizing refraction, reflection, diffraction, etc. Examples of the various components that can change the optical path include lenses, prisms, mirrors, diffractive optical elements, etc.

[0149] 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 moves on the multiple diffractive optical elements 50A-50C. That is, the diffractive optical element 50 on which the coherent light from the light source 40 is incident changes between the multiple diffractive optical elements 50A-50C. The illustrated scanning device 60 has a reflecting surface that is rotatable about one axis RA. A galvanometer mirror may be used as such a scanning device 60.

[0150] The illuminated area 96 may be divided into a plurality of partial areas 93A, 93B, and 93C according to the position in the first direction D1. A plurality of diffractive optical elements 50A to 50C may illuminate the partial areas 93A, 93B, and 93C different from each other. According to this example, the diffraction angle range of the light diffracted by one diffractive optical element 50 can be narrowed. This improves the diffraction efficiency of each diffractive optical element 50. Note that, by operating the scanning device 60 at a speed exceeding the resolution of human vision, a human sees as if all the partial areas 93A, 93B, and 93C included in the illuminated area 96 are continuously illuminated at the same time.

[0151] In the example shown in FIG. 12, the diffractive optical element 50 includes first to twelfth diffractive optical elements 50A to 50L. For example, an illuminated area 96 on a projection surface 95 is divided into first to twelfth partial areas 93A to 93L. The coherent light diffracted by the first to twelfth diffractive optical elements 50A to 50L is irradiated onto the first to twelfth partial areas 93A to 93L, respectively. 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 in accordance with the operation of the scanning device 60. As another example, a light-shielding member that blocks light enters and retreats 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 of the diffractive optical elements 50A-50L, it is possible to project coherent light onto only any of the diffractive optical elements 50A-50L. This makes it possible to illuminate only any of the first to twelfth partial regions 93A-93L, and to illuminate the illuminated region 96 in a desired shape.

[0152] The diffractive optical element 50 included in the illumination device 30 shown in FIGS. 11 and 12 may be divided into a plurality of element diffractive optical elements 55. In the embodiment shown in FIG.

[0153] In the embodiment described above, the projection system 10 includes an illumination device 30 and an optical filter 120. The illumination device 30 emits illumination light. The illumination device 30 projects the projection pattern 90 onto the projection surface 95. The average transmittance of the optical filter 120 in the wavelength range of the illumination light emitted 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 wavelength range of the illumination light. According to this embodiment, the contrast of the projection pattern 90 on the projection surface 95 is improved by observing the projection pattern 90 through the optical filter 120. This allows the projection pattern 90 to be clearly observed.

[0154] In the embodiment described above, the observation auxiliary device 100 assists in the observation of the projection pattern 90 projected on the projection surface 95 using the illumination light emitted from the illumination device 30. The observation auxiliary device 100 includes an optical filter 120. The average transmittance of the optical filter 120 in the wavelength range of the illumination light emitted 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 wavelength range of the illumination light. The wavelength range of the illumination light is a wavelength range that is 5 nm lower than the peak wavelength of the illumination light or more and 5 nm higher than the peak wavelength or less. The peak wavelength of the illumination light is the wavelength at which the maximum radiant flux of the illumination light is obtained. According to this embodiment, the contrast of the projection pattern 90 on the projection surface 95 is improved by observing the projection pattern 90 through the optical filter 120. Therefore, the observation of the projection pattern 90 is supported by the observation auxiliary device 100, and the projection pattern 90 can be clearly observed.

[0155] Although one embodiment has been described with reference to a specific example, the above-mentioned specific example does not limit the embodiment. The above-mentioned embodiment can be embodied in various other specific examples, and various omissions, substitutions, changes, additions, etc. can be made without departing from the spirit of the embodiment.

[0156] An example of the modification will be described below with reference to the drawings. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-mentioned specific example are designated by the same reference numerals as those used for the corresponding parts in the above-mentioned specific example, and duplicated descriptions will be omitted.

[0157] In the above-described specific example, an example has been shown in which the observation assistance device 100 includes the imaging device 101 and the display device 102. As shown in Fig. 13, the imaging device 101 of the observation assistance device 100 may be mounted on a moving object 80. When the projection pattern 90 projected onto the projection surface 95 by the lighting device 30 indicates the movement path of the moving object 80, the observer 5 can operate the moving object 80 while observing the image displayed on the display device 102.

[0158] 14 is a plan view showing a display surface 103 of a display device 102. An imaging device 101 captures an image of a projection surface 95, which is a road surface. A linear projection pattern 90 is projected onto the projection surface 95. An observer 5 can operate a moving object 80 while observing the image displayed on the display surface 103. This allows the moving object 80 to move along a predetermined movement path indicated by the projection pattern 90.

[0159] 14 , the display device 102 may display a reference pattern 97 together with an image captured by the imaging device 101. The reference pattern 97 may indicate a predetermined position, a predetermined direction, or a predetermined range within the range captured by the imaging device 101. The predetermined position, the predetermined direction, or the predetermined range may be a position, a direction, or a range on the projection surface 95.

[0160] 14, the reference pattern 97 indicates a planned movement path 99A of the moving body 80 if the moving body 80 maintains its current traveling. That is, the reference pattern 97 indicates a planned passing position of the moving body 80 within the imaging range of the imaging device 101. The reference pattern 97 indicates a direction in which the moving body 80 moves within the imaging range of the imaging device 101.

[0161] 14, the moving object 80 can be moved along the planned moving path with high accuracy by making the reference pattern 97 indicating the planned moving path 99A and the projection pattern 90 overlap on the display surface 103 of the display device 102. Also, by observing that the reference pattern 97 indicating the planned moving path 99A and the projection pattern 90 overlap on the display surface 103 of the display device 102, it can be confirmed that the moving object 80 is moving along the planned moving path.

[0162] The imaging device 101 may be attached to the moving object 80. In this example, the imaging device 101 can display an image of an area that is in a fixed relative relationship with the moving object 80. When the moving object 80 moves in a fixed manner, such as moving straight ahead, it passes through a fixed position within a range displayed on the display device 102 of the imaging device 101. The reference pattern 97 indicating the planned movement path 99A of the moving object 80 may be an image input to the display device 102 as image data and displayed on the display device 102, or may be a mark applied on the display surface 103 with a writing implement or tape.

[0163] The mobile body 80 may be a work vehicle that performs some kind of work. The mobile body 80 may perform some kind of work while moving. In the example shown in FIG. 17, the mobile body 80 includes a work device 84. The work device 84 can perform a predetermined work on a projection surface 95 that is the travel surface of the mobile body 80. As described above, the work device 84 may be used for line drawing work. In line drawing work, for example, a white line or an orange line can be drawn on a work target surface such as a road, a sidewalk, or a parking lot.

[0164] In an example in which the mobile object 80 is a work vehicle, the projection pattern 90 may indicate a position on the projection surface 95 where the work should be performed, a direction on the projection surface 95 where the work should be performed, and an area on the projection surface 95 where the work should be performed. In the example shown in Fig. 14, the projection pattern 90 may be a predetermined path along which the work should be performed.

[0165] 14, the reference pattern 97 may indicate a planned work route 99B along which work will be performed using the moving body 80 if the moving body 80 as a work vehicle maintains its current travel. That is, the reference pattern 97 may indicate a planned work position of the moving body 80 within the imaging range of the imaging device 101. The reference pattern 97 may indicate a direction in which the moving body 80 will proceed with work within the imaging range of the imaging device 101.

[0166] 14, by making the reference pattern 97 indicating the planned work path 99B and the projection pattern 90 overlap on the display surface 103 of the display device 102, work using the moving object 80 can be performed along the planned work path with high accuracy. Also, by observing that the reference pattern 97 indicating the planned work path 99B and the projection pattern 90 overlap on the display surface 103 of the display device 102, it can be confirmed that work using the moving object 80 is being performed along the planned work path.

[0167] However, depending on environmental conditions such as weather, the projection pattern on the projection surface may become difficult to observe. In addition, in order to display a large-area projection pattern brightly, it is necessary to increase the output of the lighting device. In this case, the output end of the lighting device becomes dazzling. Furthermore, in the example shown in FIG. 18A, the projection pattern 90 is linear. The linear projection pattern 90 is likely to be displayed brightly at a position on the projection surface 95 close to the lighting device 30. The linear projection pattern 90 may be displayed darkly at a position on the projection surface 95 far from the lighting device 30. The linear projection pattern 90 may be difficult to observe at a position on the projection surface 95 far from the lighting device 30.

[0168] In order to deal with such problems, the projection system 10 and the observation assistance device 100 may have the following configuration.

[0169] 17, the projection system 10 and the observation assistance device 100 may include a control device 130 electrically connected to the imaging device 101 and the display device 102. The control device 130 detects the projection pattern 90 from the image displayed on the display device 102.

[0170] The control device 130 generates a display pattern 92 related to the detected projection pattern. The display device 102 displays the display pattern 92 by superimposing it on the image captured by the imaging device 101.

[0171] Fig. 18A shows the projection system 10 and the display surface 103 of the display device 102 of the observation assistance device 100 shown in Fig. 17. In the example shown in Fig. 17, the illumination device 30 projects a projection pattern 90 as a linear pattern onto the projection surface 95. The linear pattern extends linearly in the first direction D1 between the illumination device 30 and the imaging device 101.

[0172] In the example shown in FIG. 18A and in FIGS. 18B to 18E to be referred to later, the projection surface 95 is a road. This road connects to other roads to form a T-junction. The projection pattern 90 extends linearly from the T-junction along the road. In the example shown in FIG. 18A, a linear projection pattern 90 is observed near the T-junction away from the imaging device 101.

[0173] In the example shown in Fig. 18B, the display device 102 displays a display pattern 92 superimposed on an image captured by the imaging device 101. The display pattern 92 includes a linear auxiliary pattern 93 that extends on an extension line of the projection pattern 80. In the example shown in Fig. 18B, the display pattern 92 is composed only of the auxiliary pattern 93. The auxiliary pattern 93 is a linear pattern similar to the projection pattern 90.

[0174] 18B, the display device 102 displays a projection pattern 90 and a connected auxiliary pattern 93 that are observed on the display surface 103. On the display surface 103 of the display device 102, the projection pattern 90 and the auxiliary pattern 93 are displayed as continuous lines.

[0175] By displaying the auxiliary pattern 93 generated by the control device 130 on the display device 102, the entire projection pattern 90 that has become partially difficult to observe due to environmental conditions, etc. can be clearly observed. This allows planned movement and work to be carried out stably according to the information shown in the projection pattern 90.

[0176] Furthermore, assuming that auxiliary pattern 93 of display pattern 92 is used, projected pattern 90 may be a part of the pattern that is originally desired to be displayed. Illuminated area 96 may be a part of the pattern that is originally desired to be displayed. In this example, on display surface 103, display pattern 92 is displayed in an area other than illuminated area 96. According to this example, the output of illumination device 30 can be reduced, and dazzling of output end 31 of illumination device 30 can be suppressed.

[0177] The control device 130 may include a CPU (Central Processing Unit) that operates based on a predetermined program. The control device 130 may include an input unit such as a keyboard or a mouse. The control device 130 may include a storage unit such as a ROM or a RAM. The control device 130 may include a storage unit such as a semiconductor drive such as an SSD. The control device 130 may include a storage unit such as a cloud server.

[0178] The control device 130 may perform wireless or wired communication with the imaging device 101. The control device 130 may acquire image data captured by the imaging device 101 from the imaging device 101. The control device 130 may detect the projection pattern 90 using the image data acquired from the imaging device 101. The control device 130 may perform wireless or wired communication with the display device 102. The control device 130 may control the display content of the display device 102. The display device 102 may be a display device such as a liquid crystal display, a plasma display, or an organic EL display. The display device 102 may include a touch panel sensor that functions as an input unit.

[0179] Fig. 19 is a flowchart relating to processing by the control device 130. The flowchart shown in Fig. 19 shows an example of a method for detecting a projection pattern 90 and generating an auxiliary pattern 93 of a display pattern 92 from an image acquired by the imaging device 101. In this example, a linear projection pattern 90 is detected, and image data of an auxiliary pattern 93 positioned on an extension line of the projection pattern 90 is generated.

[0180] In the example shown in FIG. 19, an auxiliary pattern 93 of a display pattern 92 is generated through steps S1 to S6.

[0181] First, in a first step S1, a processing region R130 is specified by trimming. In order to reduce the amount of calculation and the calculation time, only image data displayed in a partial area of ​​the display surface 103 is targeted for processing by the control device 130. This partial area becomes the processing region R130 (see FIG. 18A). The processing region R130 may be set in advance. The processing region R130 may also be set each time by the observer 5 observing the display device 102.

[0182] In a second step S2, only a specific wavelength component is extracted from the image data captured by the imaging device 101. The specific wavelength to be extracted may be the wavelength range of the illumination light emitted from the illumination device 30. The specific wavelength to be extracted may be a wavelength range of 30 nm centered on the peak wavelength of the illumination light. If the image data captured by the imaging device 101 is a monochrome image, the second step S2 is not necessary.

[0183] In the third step S3, the image obtained in the second step is smoothed by removing high frequency components from the image data using a Gaussian filter or the like.

[0184] In a fourth step S4, a group of points constituting the projection pattern 90 is searched for. Each point may be one pixel of the display device 102. In an example in which a linear projection pattern 90 is detected, a group of points constituting the projection pattern 90 may be searched for as follows.

[0185] First, the Y direction, which is the vertical direction, and the X direction, which is the horizontal direction, are defined according to the pixel arrangement of the display device 102. From the multiple pixels arranged in the X direction that belong to the top row in the Y direction, the pixel with the greatest brightness is selected. The selected pixel is set as a candidate for the point group that constitutes the projection pattern 90. The brightness of a pixel is evaluated by the gradation of the pixel.

[0186] Next, a pixel with maximum brightness is selected from among multiple pixels arranged in the X direction that belong to the row one row below in the Y direction from the row in which the point cloud candidate was first selected. The amount of shift in the X direction between the selected pixel and the pixel initially selected as the point cloud candidate is compared with a preset column threshold. If the amount of shift is equal to or less than the column threshold, the selected pixel is determined to be a candidate for a point cloud that constitutes the projection pattern 90. After that, a search is made for a pixel with maximum brightness from among multiple pixels arranged in the X direction that belong to the row one row below in the Y direction from the row in which the point cloud candidate was last selected.

[0187] If the amount of deviation in the X direction between the pixel selected as the pixel with the maximum brightness and the pixel previously selected as a point cloud candidate is greater than the column threshold, the last selected pixel is not included in the point cloud candidate. Next, the number of pixels selected as point cloud candidates, in other words, the number of consecutive rows in the Y direction from which the point cloud candidates were obtained, is compared with a preset row threshold. If the number of rows is greater than the row threshold, the pixels selected as point cloud candidates are determined to be part of the point cloud that constitutes the projection pattern 90.

[0188] If the number of rows is less than or equal to the row threshold, the previously selected pixels are deleted from the point cloud candidate, and a search for a new point cloud candidate is started in the above-mentioned manner from the row one row below in the Y direction from the row in which the maximum brightness pixel was last selected.

[0189] In this manner, a search is performed for the point group constituting the projection pattern 90. The above processing is performed for each piece of image data captured by the imaging device 101, for example, for each piece of image data acquired at 10 frames / second. For image data for which the row threshold condition is not satisfied, it is determined that the point group constituting the projection pattern 90 does not exist, i.e., the projection pattern 90 does not exist.

[0190] In a fifth step S5, the projection pattern 90 is identified from the point cloud that constitutes the projection pattern 90. The linear projection pattern 90 may be identified using the least squares method. The linear projection pattern 90 may be identified using "FitLine" of the image processing software "OpenCV." The projection pattern 90 may be identified within the range of a row in the Y direction that includes the point cloud that constitutes the projection pattern 90.

[0191] In a sixth step S6, an auxiliary pattern 93 is generated. In the fifth step, the position of the projection pattern 90 is specified as a function in an orthogonal coordinate system with axes in the X and Y directions. The auxiliary pattern 93 is specified as a function having the same inclination as the projection pattern 90. The auxiliary pattern 93 is specified as a function that connects to one end of the projection pattern 90. The auxiliary pattern 93 may extend to a column located at an end in the X direction or a row located at an end in the Y direction.

[0192] In this way, the position of the auxiliary pattern 93 on the image captured by the imaging device 101 is specified.

[0193] As shown in FIG. 18C, the display pattern 92 may include a detection pattern 94. The detection pattern 94 is displayed overlapping the projection pattern 90. That is, the detection pattern 94 is located on the detected projection pattern 90. The detection pattern 94 is displayed on the illuminated area 96 of the display device 102. According to this example, the projection pattern 90 can be brightly observed on the display surface 103 of the display device 102, regardless of the environmental conditions. This allows the planned movement or work to be stably performed according to the information shown in the projection pattern 90.

[0194] 18C, the display pattern 92 may include both an auxiliary pattern 93 and a detection pattern 94. In this example, the auxiliary pattern 93 may be connected to the detection pattern 94. The auxiliary pattern 93 may be located on an extension of the detection pattern 94. According to the display pattern 92 including the auxiliary pattern 93 and the detection pattern 94, the projection pattern 90 can be clearly observed on the display surface 103 of the display device 102 regardless of the environmental conditions. This allows the planned movement or work to be stably performed according to the information shown in the projection pattern 90.

[0195] As shown in Fig. 18C, the auxiliary pattern 93 and the detection pattern 94 may be displayed in different patterns. As shown in Fig. 18D, the auxiliary pattern 93 and the detection pattern 94 may be displayed in the same pattern. As shown in Fig. 18D, the display pattern 92 may include the auxiliary pattern 93 and the detection pattern 94 as one continuous pattern.

[0196] 18A to 18D, the display device 102 displays a reference pattern 97. As described above, the reference pattern 97 may indicate a predetermined position, a predetermined direction, or a predetermined range within an area captured by the imaging device 101. The reference pattern 97 may indicate a planned movement path 99A of the moving object 80. The reference pattern 97 may also indicate a planned work position or planned work path 99B by the working device 84 of the moving object 80.

[0197] The control device 130 may evaluate a positional relationship of the detected projection pattern 90 with respect to the reference pattern 97. The control device 130 may evaluate a positional relationship of the generated display pattern 92 with respect to the reference pattern 97. The control device 130 may evaluate a positional relationship of the generated auxiliary pattern 93 with respect to the reference pattern 97. The control device 130 may evaluate a positional relationship of the generated detection pattern 94 with respect to the reference pattern 97.

[0198] In the above example, the positional deviation between each pattern 90, 92, 93, 94 and the reference pattern 97 on the display surface 103 of the display device 102 means that the actual movement path, passing position, work path, work position, etc. of the moving body 80 are deviated from the planned movement or work path and position.

[0199] For example, when the difference in the positional relationship between each of the patterns 90, 92, 93, and 94 and the reference pattern 97 in the above-mentioned orthogonal coordinate system with axes in the X and Y directions exceeds a certain level, the control device 130 may determine that there is an "abnormality."

[0200] More specifically, the presence or absence of an abnormality may be evaluated depending on whether the difference or ratio of the slopes of the two patterns being compared is within a predetermined range. The presence or absence of an abnormality may be evaluated depending on whether the difference in the X coordinate at a certain Y coordinate of the two patterns being compared is within a predetermined range. The presence or absence of an abnormality may be evaluated depending on whether the difference in the Y coordinate at a certain X coordinate of the two patterns being compared is within a predetermined range. The presence or absence of an abnormality may be evaluated depending on whether the sum of the difference in the X coordinate at a certain Y coordinate of the two patterns being compared and the difference in the Y coordinate at a certain X coordinate of the two patterns being compared is within a predetermined range. The presence or absence of an abnormality may be evaluated depending on the distance between the two patterns being compared.

[0201] The control device 130 may report the abnormality when it determines that there is an abnormality in the positional relationship between the detected or generated patterns 90, 92, 93, 94 and the reference pattern 97. By reporting the abnormality, the position and orientation of the moving body 80 are prompted to be corrected. For example, as shown in FIG. 18E, the position and orientation of the moving body 80 are corrected so that the detected or generated patterns 90, 92, 93, 94 and the reference pattern 97 overlap. This makes it possible for the moving body 80 to move and for work to be performed using the moving body 80 according to the information displayed by the projection pattern 90.

[0202] The control device 130 may notify the observer 5 of an abnormality by a display, sound, or the like output from the display device 102. For example, when an abnormality occurs, the display method of the image captured by the imaging device 101 may be changed. When an abnormality occurs, the imaging device 101 may change the display method of the display pattern 92. When an abnormality occurs, the imaging device 101 may change the display method of the reference pattern 97. The control device 130 may display a warning on the display device 102.

[0203] 17, the projection system 10 and the observation assistance device 100 may include an alarm device 86 that notifies of an abnormality. The alarm device 86 may be a lamp or a buzzer. When the control device 130 determines that there is an abnormality in the positional relationship, the alarm device 86 may notify of the abnormality using at least one of light and sound.

[0204] The control device 130 may notify of an abnormality by changing the projection method of the projection pattern 90 onto the projection surface 95. In this example, the control device 130 is electrically connected to the lighting device 30. When the control device 130 detects an abnormality, the control device 130 may transmit a control signal to the lighting device 30 via a wired or wireless connection to change the projection method of the projection pattern 90. The change in the projection method may be one or more of a change in the projection pattern, a change in the wavelength range of the illumination light, and switching between lighting and blinking.

[0205] In the example shown in Fig. 17, the observer 5 pushes the moving object 80, causing the moving object 80 to move. While the moving object 80 moves, the working device 84 works on the projection surface 95. The moving object 80 is not limited to the above-mentioned work vehicle that draws a line on the projection surface 95. In addition, the moving object 80 may move with the observer 5 on board.

[0206] The mobile body 80 may be a work vehicle for constructing roads and sidewalks, a work vehicle for preparing roads and sidewalks, a work vehicle for performing agricultural work, or a work vehicle for preparing fields. Examples of the mobile body 80 for constructing or preparing roads and the like include a grader, an asphalt finisher, a road roller, a tire roller, a wheel loader, a mixer truck, a line puller, a snowplow, and a cleaning vehicle. Examples of the mobile body 80 for performing agricultural work and the mobile body 80 for preparing fields include a rice transplanter, a harvester, a grass cutter, a tractor, a chemical sprayer, and a tiller. The mobile body 80 may be a special vehicle or an industrial vehicle specified in ISO5053-1.

[0207] As shown in Fig. 20, the observer 5 may operate a moving body 80 using a remote control device 87 while observing the display device 102. The moving body 80 may be a train, an airplane, a ship, or a drone as shown in Fig. 21, as described above. In the example shown in Fig. 21, the moving body 80 as a drone may include a working device 84. The working device 84 mounted on the moving body 80 as a drone may be a spraying device.

[0208] The projection pattern 90 is not limited to a linear pattern. As described above, the projection pattern 90 can be changed. Figs. 22 and 23 show modified examples of the projection pattern 90 and the display pattern 92.

[0209] 22, the projection pattern 90 may include a first linear pattern 91A and a second linear pattern that intersect with each other. The first linear pattern 91A and the second linear pattern 91B may be perpendicular to each other. The projection pattern 90 may be a cross mark. The projection pattern 90 may indicate a movement target point to be finally reached by the intersection of the first linear pattern 91A and the second linear pattern 91B, or may indicate the center of a position where a task is to be performed.

[0210] In the example shown in FIG. 22, the display pattern 92 includes a first auxiliary pattern 93A and a second auxiliary pattern 93B. The first auxiliary pattern 93A is located on an extension of the first linear pattern 91A. A pair of the first auxiliary patterns 93A extend from both ends of the first linear pattern 91A. The second auxiliary pattern 93B is located on an extension of the second linear pattern 91B. A pair of the second auxiliary patterns 93B extend from both ends of the second linear pattern 91B. A large cross mark is shown by a combination of the projection pattern 90 and the display pattern 92. The display pattern 92 of the display pattern 92 may indicate an area where work should be performed by a combination of the projection pattern 90.

[0211] In the example shown in FIG. 23, the projection pattern 90 is a linear pattern extending on a circumference. The projection pattern 90 may indicate the center of an area where work is to be performed. Unlike the example shown in FIG. 23, the projection pattern 90 may be a linear pattern extending on an ellipse circumference, a linear pattern extending along the contour of a triangle, a linear pattern extending along the contour of a rectangle, or a linear pattern extending along the contour of an angular shape such as a pentagon or hexagon. The projection pattern 90 may be a circular shape, a triangular shape, a rectangular shape, or an angular shape such as a pentagon or hexagon.

[0212] 23, the display pattern 92 includes an auxiliary pattern 93 that circumferentially surrounds the projection pattern 90. The auxiliary pattern 93 may be adjacent to the projection pattern 90. The auxiliary pattern 93 may be spaced from the projection pattern 90 as in the illustrated example. The auxiliary pattern 93 spaced from the projection pattern 90 may be linear. The auxiliary pattern 93 of the display pattern 92 may be combined with the projection pattern 90 to indicate an area where an operation is to be performed.

[0213] A center of gravity 93Y of an area surrounded by an outer contour 93X of the auxiliary pattern 93 may be at the same position as at least one of a center of gravity 90Y of the projection pattern 90 and a center of gravity 90Y of an area surrounded by the outer contour 90X of the projection pattern 90. In the example shown in Fig. 23, the display pattern 92 includes auxiliary patterns 93 extending along two circumferences arranged concentrically with the projection pattern 90. The auxiliary patterns 93 may be linear extending along an ellipse circumference, like the projection pattern 90, or may be linear extending along a triangular contour, or may be linear extending along a rectangular contour, or may be linear extending along a contour of an angular shape such as a pentagon or hexagon.

[0214] Fig. 24 shows a display surface 103 of the display device 102. The display device 102 displays an image captured by the imaging device 101. The projection pattern 90 shown in Fig. 23 is projected within the imaging range of the imaging device 101. The display device 102 displays an auxiliary pattern 93 of a display pattern 92, superimposed on the image including the projection pattern 90. The display device 102 occupies a reference pattern 97, superimposed on the image including the projection pattern 90. The reference pattern 97 is a cross mark.

[0215] In the specific example shown in Fig. 24, the projection surface 95 onto which the projection pattern 90 is projected is a field in which agricultural crops are grown. It is assumed that a spray such as pesticide or fertilizer is sprayed in a predetermined spray area of ​​the field. In this assumption, the projection pattern 90 may indicate the center of the spray area. The auxiliary pattern 93 of the display pattern 92 may indicate the range of the spray area.

[0216] The reference pattern 97 may indicate a position where the material is to be sprayed depending on the orientation of the nozzle that emits the material. That is, the reference pattern 97 may indicate a planned position where the material is to be sprayed depending on the orientation of the nozzle. In this example, the imaging device 101 may be attached to the nozzle. In this example, the reference pattern 97 may be generated by the control device 130 based on the state of the working device 84.

[0217] The reference pattern 97 may include a first reference pattern 97A and a second reference pattern 97B. In the example shown in FIG. 25, the first reference pattern 97A is a cross mark indicating the planned spraying position. The second reference pattern 97B is an arrow indicating the direction in which the planned spraying position moves. The movement direction of the planned spraying position indicated by the second reference pattern 97B may be determined by processing in the control device 130 based on the operation information of the nozzle that emits the spraying material.

[0218] As described above, the control device 130 detects a pattern 90 in an image displayed on the display device 102, and generates a display pattern 92 related to the detected pattern. The display device 102 displays the display pattern 92 superimposed on the image. The observation assistance device 100 including such a control device 130 and display device 102 can also be applied to patterns other than the projection pattern projected from the lighting device 30. For example, the observation assistance device 100 including the display device 102 and control device 130 can also be applied to the observation of a pattern drawn on a surface with paint or the like.

[0219] The control device 130 may be combined with the display device 102 that displays an image captured by the imaging device 101 that does not include the optical filter 120. In this example, the control device 130 can also detect a pattern from the image, thereby superimposing the display pattern 92 on the image. [Explanation of symbols]

[0220] D1: first direction, D2: second direction, D3: third direction, 5: observer, 10: projection system, 30: lighting device, 31: output end, 40: light source, 45: shaping optical system, 46: first lens, 47: second lens, 48: third lens, 50: diffractive optical element, 55: elementary diffractive optical element, 60: scanning device, 70: casing, 71: cylindrical portion, 71a: step portion, 72: lid portion, 73: spacing ring, 74: battery, 75: circuit, 76: switch, 80: moving body, 81: windshield, 82: partition member, 84: working device, 86: notification device, 90: projection pattern line, 92: display pattern, 93: auxiliary pattern, 94: detection pattern, 95: projection surface, 96: illuminated area, 97: reference pattern, 100: observation auxiliary device, 101: imaging device, 101a: imaging element, 102: display device, 104: mounting fixture, 105: light-shielding wall portion, 106: frame, 106A: frame body, 106B: holding portion, 107: mounting fixture body, 108: contact lens body, 120: optical filter, 121: substrate, 122: dielectric multilayer film, 122a: low refractive index layer, 122b: high refractive index layer, 130: control device

Claims

1. An observation assistance device that assists in observation of a projection pattern projected onto a projection surface using illumination light emitted from an illumination device, comprising: an optical filter having an average transmittance in the wavelength range of the illumination light higher than an average transmittance in a visible light wavelength range other than the wavelength range of the illumination light; the wavelength range of the illumination light is a wavelength range of at least one wavelength that is 5 nm lower than a peak wavelength of the illumination light, and at most one wavelength that is 5 nm higher than the peak wavelength of the illumination light, An observation auxiliary device, wherein the peak wavelength of the illumination light is a wavelength at which a maximum radiant flux of the illumination light is obtained.

2. a wearing device that can be worn by an observer of the projection pattern; the mounting includes the optical filter, 2. The observation auxiliary device according to claim 1, wherein the optical filter faces the observer's eye when the observer wears the wearing tool.

3. The observation assistance device according to claim 1 , comprising an imaging device including the optical filter.

4. An observation assistance device that assists in observation of a pattern displayed on a surface, comprising: a display device that displays an image of the surface; A control device electrically connected to the display device, the controller detects the pattern in the image displayed on the display device and generates a display pattern related to the detected pattern; The display device displays the display pattern superimposed on the image, thereby providing an observation assistance device.

5. 5. The observation assistance device according to claim 4, further comprising an illumination device for projecting the pattern onto a surface.

Images