Projection system and observation assistance device

Abstract

The projection system includes an illumination device and an optical filter. The illumination device emits illumination light. The lighting device projects the projection pattern onto the projection surface. The average transmittance of the optical filter in the wavelength band of the illumination light emitted from the illumination device is higher than the average transmittance of the optical filter in the visible light wavelength band other than the wavelength band of the illumination light.

Description

Technical Field

[0001] The invention relates to a projection system and a viewing aid. Background Art

[0002] A lighting device that projects a projection pattern onto a projection surface such as a road surface is known (for example, JP2021-52008A). Depending on the ambient light in the environment where the lighting device is used, the contrast of the projection pattern decreases, making it difficult to observe the projection pattern. Summary of the invention

[0003] The purpose of the present disclosure is to enable the projection pattern to be clearly observed.

[0004] A projection system according to one embodiment of the present disclosure comprises:

[0005] an illumination device that emits illumination light and projects a projection pattern onto a projection surface; and

[0006] an optical filter having an average transmittance in the wavelength band of the illumination light higher than an average transmittance in a visible light band other than the wavelength band of the illumination light,

[0007] The wavelength band of the illumination light is a wavelength band that is greater than or equal to a wavelength that is 5 nm lower than a peak wavelength of the illumination light and less than or equal to a wavelength that is 5 nm higher than the peak wavelength.

[0008] The peak wavelength of the illumination light is a wavelength at which the maximum radiant flux of the illumination light can be obtained.

[0009] A first observation assisting device according to one embodiment of the present disclosure is an observation assisting device for assisting observation of a projection pattern projected onto a projection surface using illumination light emitted from an illumination device, wherein:

[0010] The observation support device includes an optical filter having an average transmittance in the wavelength band of the illumination light higher than an average transmittance in a visible light band other than the wavelength band of the illumination light.

[0011] The wavelength band of the illumination light is a wavelength band that is greater than or equal to a wavelength that is 5 nm lower than a peak wavelength of the illumination light and less than or equal to a wavelength that is 5 nm higher than the peak wavelength.

[0012] The peak wavelength of the illumination light is a wavelength at which the maximum radiant flux of the illumination light can be obtained.

[0013] A second observation assisting device according to one embodiment of the present disclosure is an observation assisting device for assisting observation of a pattern displayed on a surface, wherein:

[0014] The observation auxiliary device comprises:

[0015] A display device that displays an image obtained by photographing the surface; and

[0016] a control device electrically connected to the display device,

[0017] The control device detects the pattern in the image displayed on the display device and generates a display pattern associated with the detected pattern.

[0018] The display device displays the display pattern in an overlapping manner with the image.

[0019] According to one embodiment of the present disclosure, the projection pattern can be clearly observed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a diagram for explaining one embodiment and is a perspective view showing an example of a projection system and an observation assisting device.

[0021] Figure 2A It is a perspective view showing an example of an observation assisting device.

[0022] Figure 2B It shows that you are wearing Figure 2A A perspective view of an observer of the viewing aid is shown.

[0023] Figure 2C It is shown Figure 2A A perspective view of a variation of the viewing aid shown.

[0024] Figure 3A It is a perspective view showing another example of the observation assisting device.

[0025] Figure 3B It shows that you are wearing Figure 3A A perspective view of an observer of the viewing aid is shown.

[0026] Figure 4 This is a side view showing still another example of the observation support device together with the observer.

[0027] Figure 5 It is a side sectional view showing still another example of the observation assisting device.

[0028] Figure 6 It is a side view showing another example of the projection system and the observation assisting device.

[0029] Fig. 7A is a graph showing an example of a transmission spectrum of an optical filter that may be included in a projection system and an observation assistance device.

[0030] Figure 7B1 is a cross-sectional view showing an example of a layer structure of an optical filter that can be included in a projection system and an observation support device.

[0031] Figure 8 This is a perspective view showing an example of a lighting device.

[0032] Fig. 9 It is a perspective view showing another example of the lighting device.

[0033] Fig.10 This is a cross-sectional view showing still another example of the lighting device.

[0034] Fig.11 This is a side view showing still another example of the lighting device.

[0035] Fig.12 This is a diagram for explaining still another example of the lighting device.

[0036] Fig.13 This is a side view showing still another example of the observation support device.

[0037] Fig.14 It shows that it can be included in Fig.13 A top view of a display device in an observation aid device.

[0038] Fig.15 It is a longitudinal sectional view showing an example of a moving body.

[0039] Fig.16 It is a perspective view showing a wearable display device.

[0040] Fig.17 This is a side view showing still another example of the projection system and the observation assisting device.

[0041] Fig.18A is with Fig.14 A corresponding figure, and a figure showing the display surface of the display device.

[0042] Fig.18B is with Fig.14 A corresponding figure, and a figure showing the display surface of the display device.

[0043] Fig. 18C is with Fig.14 A corresponding figure, and a figure showing the display surface of the display device.

[0044] Fig.18D is with Fig.14 A corresponding figure, and a figure showing the display surface of the display device.

[0045] Fig.18E is with Fig.14 A corresponding figure, and a figure showing the display surface of the display device.

[0046] Fig.19 This is a flowchart showing an example of a method of generating a display pattern by a control device.

[0047] Fig. 20 This is a side view showing still another example of the projection system and the observation assisting device.

[0048] Fig.21 This is a side view showing still another example of the projection system and the observation assisting device.

[0049] Fig. 22 It is a top view showing a modified example of the projection pattern and the display pattern.

[0050] Fig.23 It is a top view showing another modified example of the projection pattern and the display pattern.

[0051] Fig.24 is with Fig.14 A corresponding figure, and a figure showing the display surface of the display device.

[0052] Fig.25 is with Figure 1 The corresponding figure is a stereoscopic diagram illustrating a conventional malfunction. DETAILED DESCRIPTION

[0053] One embodiment of the present disclosure relates to the following [1] to

[40] . [1]

[0055] A projection system, wherein:

[0056] The projection system comprises:

[0057] an illumination device that emits illumination light and projects a projection pattern onto a projection surface; and

[0058] an optical filter having an average transmittance in the wavelength band of the illumination light higher than an average transmittance in a visible light band other than the wavelength band of the illumination light,

[0059] The wavelength band of the illumination light is a wavelength band that is greater than or equal to a wavelength that is 5 nm lower than a peak wavelength of the illumination light and less than or equal to a wavelength that is 5 nm higher than the peak wavelength.

[0060] The peak wavelength of the illumination light is a wavelength at which the maximum radiant flux of the illumination light can be obtained. [2]

[0062] The projection system according to [1], wherein:

[0063] In the projection system, the projected pattern is observed through the optical filter. [3]

[0065] The projection system according to [1] or [2], wherein:

[0066] The projection system includes a wearable item that can be worn by an observer of the projection pattern.

[0067] The wearable device includes the optical filter,

[0068] In a state where the observer wears the wearing tool, the optical filter faces the eyes of the observer. [4]

[0070] The projection system according to [3], wherein:

[0071] The wearing member includes a light shielding wall portion located around the optical filter.

[0072] When the observer wears the wearing tool, the light shielding wall portion is located between the optical filter and the observer. [5]

[0074] The projection system according to [3] or [4], wherein:

[0075] The wearing piece includes a wearing piece body worn on the head,

[0076] The optical filter is attachable to and detachable from the wearing tool body. [6]

[0078] A projection system according to [3], wherein

[0079] The wearing item includes a contact lens, and the contact lens includes the optical filter. [7]

[0081] The projection system according to [1] or [2], wherein:

[0082] The optical filter constitutes a windshield of the moving body. [8]

[0084] The projection system according to [1], wherein:

[0085] The projection system includes an imaging device including the optical filter. [9]

[0087] The projection system according to [8], wherein:

[0088] The projection system includes a display device electrically connected to the imaging device.

[0089] The display device displays the image captured by the imaging device.

[10]

[0091] The projection system according to [9], wherein:

[0092] The display device includes a wearing accessory that can be worn by an observer, and a display element that is held by the wearing accessory and displays the image.

[0093] In a state where the observer wears the wearing tool, the display element faces the eyes of the observer.

[11]

[0095] The projection system according to

[10] , wherein:

[0096] The total light transmittance of the display element is greater than 1%.

[12]

[0098] The projection system according to any one of [9] to

[11] , wherein:

[0099] The projection system includes a control device electrically connected to the imaging device and the display device.

[0100] The control device detects the projection pattern in the image displayed on the display device and generates a display pattern associated with the detected projection pattern.

[0101] The display device displays the display pattern in an overlapping manner with the image.

[13]

[0103] The projection system according to

[12] , wherein:

[0104] The projection pattern comprises a linear pattern,

[0105] The display pattern includes a linear auxiliary pattern extending on an extension line of the projection pattern.

[14]

[0107] The projection system according to

[12] or

[13] , wherein:

[0108] The projection pattern includes a linear pattern,

[0109] The display pattern includes a linear auxiliary pattern located on an extension line of the projection pattern.

[15]

[0111] The projection system according to

[12] or

[13] , wherein:

[0112] The projection pattern includes a first linear pattern and a second linear pattern that intersect each other.

[0113] The display pattern includes: a linear first auxiliary pattern located on an extension line of the first linear pattern; and a linear second auxiliary pattern located on an extension line of the second linear pattern.

[16]

[0115] The projection system according to

[12] or

[13] , wherein:

[0116] The display pattern includes an auxiliary pattern surrounding the projection pattern.

[17]

[0118] The projection system according to

[16] , wherein:

[0119] The centroid of the area surrounded by the outer contour of the auxiliary pattern is located at the same position as at least one of the centroid of the projection pattern and the centroid of the area surrounded by the outer contour of the projection pattern.

[18]

[0121] The projection system according to any one of

[12] to

[17] , wherein:

[0122] The display pattern includes a detection pattern that overlaps with the detected projection pattern.

[19]

[0124] The projection system according to any one of

[12] to

[18] , wherein:

[0125] The display pattern includes an auxiliary pattern, and the auxiliary pattern is connected to the detection pattern and is located on an extension line of the detection pattern.

[20]

[0127] The projection system according to any one of [9] to

[19] , wherein:

[0128] The camera device can move relative to the projection surface.

[0129] 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. [twenty one]

[0131] The projection system according to

[20] , wherein:

[0132] The projection system includes a movable body capable of moving relative to the projection surface.

[0133] The imaging device is held by the moving object. [twenty two]

[0135] The projection system according to

[21] , wherein:

[0136] The reference pattern indicates at least one of a planned movement path of the movable body and a planned position of a work to be performed by the movable body. [twenty three]

[0138] The projection system according to any one of

[12] to

[22] , wherein:

[0139] 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.

[0140] 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,

[0141] When the control device determines that there is an abnormality in the positional relationship, the control device reports the abnormality. [twenty four]

[0143] The projection system according to

[23] , wherein:

[0144] The display device reports the abnormality by changing a display method of at least one of the image and the display pattern.

[25]

[0146] The projection system according to

[23] or

[24] , wherein:

[0147] The projection system includes a reporting device for reporting the abnormality.

[0148] When the control device determines that there is an abnormality in the positional relationship, the reporting device reports the abnormality using at least one of light and sound.

[26]

[0150] The projection system according to any one of

[23] to

[25] , wherein:

[0151] The lighting device reports the abnormality by changing a method of projecting the projection pattern onto the projection surface.

[27]

[0153] The projection system according to any one of [1] to

[26] , wherein:

[0154] The optical filter includes a dielectric multilayer film.

[28]

[0156] The projection system according to any one of [1] to

[27] , wherein:

[0157] The full width at half maximum of the spectral transmittance of the optical filter is less than 15 nm.

[29]

[0159] The projection system according to any one of [1] to

[28] , wherein:

[0160] The maximum spectral transmittance of the optical filter in the visible light band is greater than 50%.

[30]

[0162] The projection system according to any one of [1] to

[29] , wherein:

[0163] The average transmittance of the optical filter in a visible light band other than a 30 nm band centered around the peak wavelength of the illumination light is 1% or less.

[31]

[0165] The projection system according to any one of [1] to

[30] , wherein:

[0166] The optical filter has an average transmittance of 0.001% or more in a visible light band other than a 30 nm band centered on a peak wavelength of the illumination light.

[32]

[0168] The projection system according to any one of [1] to

[31] , wherein:

[0169] The maximum value of the illumination of the projection pattern projected onto the projection surface is greater than or equal to 1 lx.

[33]

[0171] The projection system according to any one of [1] to

[32] , wherein:

[0172] The maximum value of the illumination of the projection pattern projected onto the projection surface, that is, the illumination LX (lx),

[0173] Illuminance LY(lx) caused by ambient light at the position on the projection surface where the illuminance LX is obtained,

[0174] an average transmittance TX (%) of the optical filter in the wavelength band of the illumination light, and

[0175] The average transmittance TY (%) of the optical filter in the visible light band other than the 30 nm band centered on the peak wavelength of the illumination light satisfies the following relationship,

[0176] 0.001≤(LX·TX) / (LY·TY).

[34]

[0179] The projection system according to

[33] , wherein:

[0180] The illuminance LX, the illuminance LY, the average transmittance TX, and the average transmittance TY satisfy the following relationship,

[0181] (LX·TX) / (LY·TY)≤10.

[35]

[0184] The projection system according to any one of [1] to

[34] , wherein:

[0185] 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.

[36]

[0187] An observation assisting device assists observation of a projection pattern projected onto a projection surface using illumination light emitted from an illumination device, wherein:

[0188] The observation support device includes an optical filter having an average transmittance in the wavelength band of the illumination light higher than an average transmittance in a visible light band other than the wavelength band of the illumination light.

[0189] The wavelength band of the illumination light is a wavelength band that is greater than or equal to a wavelength that is 5 nm lower than a peak wavelength of the illumination light and less than or equal to a wavelength that is 5 nm higher than the peak wavelength.

[0190] The peak wavelength of the illumination light is a wavelength at which the maximum radiant flux of the illumination light can be obtained.

[37]

[0192] The observation assisting device according to

[36] , wherein:

[0193] The observation assisting device includes a wearable device that can be worn by an observer of the projection pattern.

[0194] The wearable device includes the optical filter,

[0195] In a state where the observer wears the wearing tool, the optical filter faces the eyes of the observer.

[38]

[0197] The observation assisting device according to

[36] or

[37] , wherein:

[0198] The observation support device includes an imaging device including the optical filter.

[39]

[0200] An observation assisting device assists observation of a pattern displayed on a surface, wherein:

[0201] The observation auxiliary device comprises:

[0202] A display device that displays an image obtained by photographing the surface; and

[0203] a control device electrically connected to the display device,

[0204] The control device detects the pattern in the image displayed on the display device and generates a display pattern associated with the detected pattern.

[0205] The display device displays the display pattern in an overlapping manner with the image.

[40]

[0207] The observation assisting device according to

[39] , wherein:

[0208] The observation support device includes a lighting device that projects the pattern onto a surface.

[0209] Hereinafter, one embodiment of the present disclosure will be described with reference to the accompanying drawings. In addition, in the drawings attached to this specification, for the sake of convenience of illustration and understanding, the scale and aspect ratio are appropriately changed and exaggerated relative to the scale and aspect ratio of the actual object.

[0210] In this specification, the candidates of multiple upper limits and multiple lower limits associated with the numerical range are sometimes recorded as other expressions. In this record, the numerical range can also be composed by combining the candidates of any upper limit and any lower limit. As an example, "Parameter B can be above A1, above A2, or above A3. Parameter B can be below A4, below A5, or below A6." This record is studied. In this example, the numerical range of parameter B can be above A1 and below A4, can be above A1 and below A5, can be above A1 and below A6, can be above A2 and below A4, can be above A2 and below A5, can be above A2 and below A6, can be above A3 and below A4, can be above A3 and below A5, can be above A3 and below A6.

[0211] In order to clarify the directional relationship between the drawings, in some drawings, the first direction D1, the second direction D2, and the third direction D3 are indicated by arrows as directions common to the drawings. The end side of the arrow becomes the first side of each direction D1, D2, and D3. Figure 6 As shown, an arrow indicating the depth of the drawing along a direction perpendicular to the drawing surface is indicated by a mark with an x ​​in a circle. Fig.10 As shown, an arrow heading forward from the paper surface in a direction perpendicular to the paper surface of the drawing is represented by a dotted symbol in a circle.

[0212] The shapes, geometric conditions and the degrees to which they are determined, such as terms such as "parallel", "orthogonal", "same", or values ​​of lengths and angles, used in this specification are not limited to strict meanings but are interpreted within a range that includes the degree to which the same function can be expected.

[0213] The projection system 10 in this embodiment includes an illumination device 30 and an observation assisting 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, it is contemplated that the observer 5 can clearly observe the projection pattern 90. Specifically, the projection system 10 includes the observation assisting device 100. The observation assisting device 100 includes an optical filter 120. The average transmittance of the optical filter 120 in the wavelength band 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 band outside the wavelength band of the illumination light. By using the optical filter 120, the observer 5 can clearly observe the projection pattern 90.

[0214] Hereinafter, one embodiment will be described with reference to specific examples shown in the drawings.

[0215] The lighting device 30 projects illumination light onto the illuminated region 96 of the projection surface 95. The observer 5 recognizes the illuminated region 96 as a projection pattern 90. The projection pattern 90 has the same shape as that of the illuminated region 96.

[0216] The projection surface 95 to which the illumination light is irradiated from the illumination device 30 is not particularly limited. In particular, according to the present embodiment, the visibility of the projection pattern 90 is improved by the observation auxiliary device 100. Therefore, the projection surface 95 may also be Figure 1 As the projection surface 95 on which the projection pattern 90 is projected, examples include roads, sidewalks, ground surfaces such as stadiums and parks, water surfaces such as sea surfaces, and outer walls, inner walls, passages, floors, ceilings, etc. of buildings such as schools, companies, buildings, factories, assembly halls, lecture halls, gymnasiums, arenas, and conference halls.

[0217] The projection pattern 90 and the illuminated area 96 are not particularly limited. The projection pattern 90 and the illuminated area 96 may also include a single area. The projection pattern 90 and the illuminated area 96 may also include a plurality of areas separated from each other. The projection pattern 90 may also include any one or more of text, patterns, geometric patterns, signs, marks, illustrations, characters, and pictograms. The projection pattern 90 may also display information.

[0218] exist Figure 1 In the example shown, 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 away from the installation position of the lighting device 30. The projection pattern 90 and the illuminated area 96 are linear. The projection pattern 90 and the illuminated area 96 have a long side direction in the first direction D1. The projection pattern 90 and the illuminated area 96 have a short side direction in the second direction D2.

[0219] The lighting device 30 projects lighting light of a specific wavelength band onto the projection surface 95. The lighting light may also be coherent light. Coherent light is light with the same wavelength and phase. The lighting light may also include coherent light of a single wavelength. The lighting light may also be green light with a wavelength of 520nm. The lighting light may also be green light with a wavelength of 530nm. The lighting light may also be red light with a wavelength of 635nm. The lighting light may also be red light with a wavelength of 638nm. The lighting light may also include coherent light of multiple wavelengths. The lighting light may also be visible light.

[0220] The observation assisting device 100 includes an optical filter 120. The transmittance of the optical filter 120 has wavelength dependence. The optical filter 120 selectively transmits the illumination light emitted from the illumination device 30 in the 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 band 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 outside the wavelength band of the illumination light.

[0221] The average transmittance (%) is determined as the arithmetic mean of the spectral transmittance per 1 nm in the target wavelength band. The spectral transmittance (%) is the transmittance associated with the wavelength k (nm) in the target wavelength band, where k is a natural number. The wavelength band of the illumination light is determined to be a wavelength greater than 5 nm lower than the peak wavelength of the illumination light and less than 5 nm higher than the peak wavelength.

[0222] As an example, if the peak wavelength is 500nm, the wavelength band of the illumination light is a wavelength band of 495nm to 505nm. In this example, the "average transmittance in the wavelength band of the illumination light" is the arithmetic mean of the spectral transmittance (%) for each wavelength of 495nm, 496nm, 497nm, 498nm, 499nm, 500nm, 501nm, 502nm, 503nm, 504nm and 505nm. In this example, the "average transmittance of the optical filter 120 in the visible light band other than the wavelength band of the illumination light" is the arithmetic mean of the spectral transmittance (%) measured every 1nm in the wavelength bands of 380nm to 494nm and 506nm to 780nm.

[0223] The spectral transmittance was measured in accordance with JIS Z 8722:2009. The geometric condition e specified in JIS Z8722:2009 was used in the measurement of the spectral transmittance. The measurement environment for measuring the spectral transmittance was 23°C ± 2°C and 50% ± 5% relative humidity. The sample was placed in the measurement environment for 16 hours before the measurement. The light source was a D65 light source. The light source was turned on for 15 minutes before the measurement to stabilize the output of the light source.

[0224] The peak wavelength of the illumination light is set to a wavelength (nm) within the visible light band at which the maximum radiation flux (W) of the illumination light can be obtained. The peak wavelength of the illumination light is determined as a natural number (nm). The peak wavelength is measured using a spectrometer. The peak wavelength is measured in accordance with the measurement method for the peak oscillation wavelength described in JIS C 5941:1997. However, the illumination light of the measurement object is regarded as the light emission from a semiconductor laser within the specification. Regarding the measurement environment when measuring the peak wavelength, the temperature is 23°C ± 2°C, the relative humidity is 50% ± 5%, and the air pressure is 860 hPa or more and 1060 hPa or less. Before starting the measurement, light the lighting device for 15 minutes to stabilize the output of the lighting device.

[0225] like Figure 2A to Figure 5 As shown, the projection system 10 and the observation auxiliary device 100 may also include a wearing member 104 that can be worn by the observer 5. The wearing member 104 includes an optical filter 120. When the observer 5 wears the wearing member 104, the optical filter 120 faces the eyes of the observer 5. The observer 5 observes the projection pattern 90 through the optical filter 120, whereby the observer 5 can clearly observe the projection pattern 90 even in a bright environment, for example.

[0226] like Figure 2A As shown, the wearable item 104 may also be glasses. The wearable item 104 may also be sunglasses. Figure 2B Shown wearing Figure 2ASunglasses for observers 5. Figure 2A and Figure 2B As shown, the wearing member 104 may include an optical filter 120, a frame 106, and a light shielding wall portion 105. Figure 2A and Figure 2B In the specific example shown, the frame 106 holds the optical filter 120. The frame 106 includes a frame body 106A that holds the optical filter 120, and a holding portion 106B for allowing the observer 5 to hold the frame body 106A. The frame body 106A holds one optical filter 120 facing the right eye and one optical filter 120 facing the left eye, similarly to ordinary glasses. The holding portion 106B is an ear hook portion. The light shielding wall portion 105 is located around the optical filter 120. Figure 2B As shown, when the observer 5 wears the wearing member 104, the shading wall portion 105 is located between the optical filter 120 and the observer 5. The shading wall portion 105 has a visible light shading property. The shading wall portion 105 may also have a function of absorbing visible light. The shading wall portion 105 may also have a function of reflecting visible light. By providing the shading wall portion 105, it is possible to suppress ambient light from entering between the observer 5's eyes and the optical filter 120 from the side.

[0227] Figure 2C Another specific example of a wearing accessory is shown. Figure 2C As shown, the wearable device 104 may also be goggles. The goggles may also include a pair of optical filters 120. Figure 2C As shown, the goggles may also include a single optical filter 120. Figure 2C In the illustrated example, when the observer 5 wears the wearing device 104 , both eyes of the observer 5 face a single optical filter 120 . Figure 2C The wearing member 104 shown includes an optical filter 120 and a frame 106. The frame 106 includes a frame body 106A for holding the optical filter 120, and a holding portion 106B for fixing the frame body 106A to the observer 5. The holding portion 106B may also be a rubber member held on the head of the observer 5. A pair of ends of the holding portion 106B are connected to the respective ends of the frame body 106A. The frame body 106A also serves as a light-shielding wall portion 105. The frame body 106A as the light-shielding wall portion 105 is connected to the optical filter 120 from the periphery. When the observer wears the wearing member 104, the frame body 106A as the light-shielding wall portion 105 is located between the optical filter 120 and the observer 5. The frame body 106A as the light-shielding wall portion 105 can suppress ambient light from entering between the optical filter 120 and the observer 5 from the side.

[0228] like Figure 3A and Figure 3BAs shown, the wearing piece 104 may also be goggles. Figure 3A and Figure 3B In the specific example shown, 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 can also be rubber parts or ropes. Figure 3B As shown, each retaining portion 106B can also be hung on the ear of the corresponding side. Figure 3B In the example shown, when the wearing tool 104 is worn, the periphery of the optical filter 120 is in contact with the face of the observer 5. This can suppress the entry of ambient light between the optical filter 120 and the observer 5 from the side.

[0229] like Figure 4 As shown, the wearable device 104 includes an optical filter 120 and a wearable device body 107 worn on the head. The wearable device body 107 may also be a helmet. The wearable device body 107 may also be a hat. The optical filter 120 may be goggles. The optical filter 120 is mounted on the wearable device body 107. When the observer 5 wears the wearable device body 107 on the head, the optical filter 120 faces the eyes of the observer 5. In the example shown in the figure, Figure 3B Similarly to the example of , the periphery of the optical filter 120 contacts the face of the observer 5. Thus, it is possible to suppress the entry of ambient light from the side between the optical filter 120 and the observer 5. The optical filter 120 may be detachable from the wearing tool body 107.

[0230] like Figure 5 As shown, the wearing member 104 may also be a contact lens. The wearing member 104 as a contact lens may also include a contact lens body 108 and an optical filter 120 stacked on the contact lens body 108. When the observer 5 wears the contact lens on the eye, the optical filter 120 faces the eye through 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 observer 5 from the side.

[0231] like Fig.15 As shown, the optical filter 120 may also be included in the windshield 81 of the mobile body 80. The mobile body 80 is a movable device. The mobile body 80 may be a car, a train, a ship, an airplane, or a drone. The mobile body 80 may or may not be able to carry people. The windshield 81 may be provided at an opening such as a window of the mobile body 80. The windshield 81 may also function as a windproof member. The windshield 81 may also be a partitioning member 82 such as a window member that partitions the interior of the mobile body 80 relative to the exterior.

[0232] Alternatively, the observer 5 can 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 even in a bright environment. When the incidence of ambient light from other openings of the moving body 80 to the inside of the moving body 80 is suppressed, the observer 5 can observe the projection pattern 90 more clearly. Fig.15 As shown, the observer 5 can also manipulate the moving object 80 .

[0233] like Figure 6 As shown, the projection system 10 and the observation auxiliary device 100 may also include an imaging device 101. The imaging device 101 includes an optical filter 120 and an imaging element 101a. Light that has passed through the optical filter 120 is incident on the imaging element 101a. The imaging device 101 captures a projection surface 95 including an illuminated area 96. The observer 5 observes the projection surface 95 captured by the imaging device 101. Thus, the observer 5 can clearly observe the projection pattern 90 even in a bright environment, for example.

[0234] like Figure 6 As shown, the projection system 10 and the observation auxiliary device 100 may also include a display device 102 electrically connected to the camera device 101. The display device 102 displays the image captured by the camera device 101. The observer 5 can clearly observe the projection pattern 90 displayed on the display device 102. The display device 102 may also be a display device such as a liquid crystal display, a plasma display, an organic EL display, a projection type display device, etc. The display device 102 may also include a touch panel sensor that functions as an input unit.

[0235] When the operation is performed only by observing the captured projection surface 95 from the display device 102, the illumination light does not need to be limited to the visible light band. For example, the camera device 101 can be an infrared camera, the illumination light can be infrared light, and the center wavelength of the optical filter can be in the infrared band.

[0236] like Fig.16 As shown, the display device 102 may also include a wearing member 102B and a display element 102A. The observer 5 can wear the wearing member 102B. The wearing member 102B holds the display element 102A. When the observer 5 wears the wearing member 102B, the display element 102A faces the eyes of the observer 5. When the observer 5 wears the wearing member 102B, the image displayed on the display element 102A can be observed. Such a display device 102 is a wearable display device.

[0237] The display device 102 may also be VR (Virtual Reality) glasses, AR (Argumented Reality) glasses, or a head-mounted display. In the wearable display device 102, the observer 5 may also be able to see through the wearable component 102B. In this example, the total light transmittance of the wearable component 102B may be greater than 1%, greater than 10%, greater than 30%, greater than 50%, greater than 60%, greater than 70%, or greater than 80%.

[0238] When the operation is performed only by observing the image from the camera device or sensor built into the display device 102, the illumination light does not need to be limited to the visible light band. For example, when the camera device built into the display device 102 is an infrared camera or an infrared sensor, the illumination light can also be infrared light and the center wavelength of the optical filter can be in the infrared band.

[0239] The upper limit of the total light transmittance of the wearing tool 102B is not particularly set. The total light transmittance of the wearing tool 102B may be, for example, 100% or less, or may be less than 100%.

[0240] A D65 light source is used in the measurement of the total light transmittance (%). The wavelength band of light used in the measurement of the total light transmittance (%) is above 380nm and below 780nm. 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 incident angle relative to the sample when measuring the total light transmittance is 0°. Regarding the measurement environment when measuring the total light transmittance, the temperature is 23°C±2°C and the relative humidity is 50%±5%. Before the measurement starts, the sample is placed in the measurement environment for 16 hours. Other measurement conditions when measuring the total light transmittance are in accordance with JIS K7361-1:1997.

[0241] Fig. 7A An example of the transmission spectrum of the optical filter 120 in the visible light band is shown. The optical filter 120 may also selectively transmit only the illumination light emitted from the lighting device 30. In the present embodiment, the average transmittance of the optical filter 120 in the wavelength band of the illumination light is higher than the average transmittance of the optical filter 120 in the visible light band outside the wavelength band of the illumination light. Thus, even if the amount of ambient light such as sunlight irradiating the projection surface 95 is large, the observer 5 can clearly observe the projection pattern 90 on the projection surface 95 through the optical filter 120. On the basis of the expected function of the optical filter 120, the wavelength band of the illumination light emitted from the lighting device 30 may be sufficiently narrow. From this point of view, the illumination light may also be coherent light. The illumination light may also be a laser of a specific wavelength.

[0242] A lower limit may also be set for the average transmittance of the optical filter 120 in the wavelength band of the illumination light. By setting a lower limit for the average transmittance, the illumination light can pass through the optical filter 120 with a 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 band of the illumination light may be 50% or more, 70% or more, or 80% or more.

[0243] The upper limit of the average transmittance of the optical filter 120 in the wavelength band of the illumination light is not particularly set. The average transmittance of the optical filter 120 in the wavelength band 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 band of the illumination light may be 50% or more and 100% or less.

[0244] Similarly, a lower limit may be set for the maximum spectral transmittance of the optical filter 120 in the visible light band. By setting a lower limit for the maximum spectral transmittance, the illumination light can pass through the optical filter 120 with a 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 band may be greater than 50%, greater than 70%, or greater than 80%. In addition, when the illumination light is a single wavelength, the average transmittance (%) of the optical filter 120 in the wavelength band of the illumination light may be the same as the maximum spectral transmittance (%) of the optical filter 120 in the visible light band.

[0245] The upper limit of the maximum spectral transmittance of the optical filter 120 in the visible light band is not particularly set. The maximum spectral transmittance of the optical filter 120 in the visible light band may be 100% or less, or less than 100%. The maximum spectral transmittance of the optical filter 120 in the visible light band may be 50% or more and 100% or less.

[0246] The full width at half maximum FWHM of the spectral transmittance of the optical filter refers to the width (nm) of the band of transmittance that can obtain more than half of the maximum transmittance in the wavelength distribution of the spectral transmittance. An upper limit can also be set for the full width at half maximum FWHM of the spectral transmittance of the optical filter. By setting an upper limit for the full width at half maximum FWHM, illumination light of a specific band can be concentrated and transmitted through the optical filter 120. In the case where the wavelength band of the illumination light is narrow, for example, when the illumination light is coherent light, or when the illumination light is laser, the illumination light can be concentrated and transmitted through the optical filter 120. At the same time, it is possible to suppress ambient light such as sunlight from passing through the optical filter 120. Therefore, when observing the projection pattern 90 through the optical filter 120, the ambient light can be weakened and the projection pattern 90 can be emphasized. That is, the contrast of the projection pattern 90 can be improved. Thus, the projection pattern 90 can be clearly observed. From this point of view, the full width at half maximum FWHM of the spectral transmittance of the optical filter can be less than 15nm, less than 3nm, or less than 1nm.

[0247] 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 greater than 0 nm and less than 15 nm.

[0248] An upper limit may also be set for the average transmittance of the optical filter 120 in the visible light band other than the wavelength band of the illumination light. By setting an upper limit for the average transmittance, it is possible to suppress ambient light such as sunlight from passing through the optical filter 120. As a result, the contrast of the projection pattern 90 is improved, and the projection pattern 90 can be clearly observed. The average transmittance of the optical filter 120 in the visible light band other than the wavelength band of the illumination light may be 1% or less, 0.1% or less, or 0.01% or less.

[0249] It is also possible to set a lower limit for the average transmittance of the optical filter 120 in the visible light band outside the wavelength band of the illumination light. By setting a lower limit for the average transmittance, even when the amount of ambient light is small, 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. As a result, the processing of the optical filter 120 can be the same between the case where the projection surface 95 is brighter and the case where the projection surface 95 is darker, and the projection pattern 90 can be clearly observed through the optical filter 120 in both cases. The average transmittance of the optical filter 120 in the visible light band outside the wavelength band of the illumination light can be 0.001% or more, 0.005% or more, or 0.01% or more.

[0250] The average transmittance of the optical filter 120 in the visible light band other than the wavelength band of the illumination light may be 0.001% or more and 1% or less.

[0251] An upper limit may be set for the average transmittance of the optical filter 120 in the visible light band other than the 30 nm band centered on the peak wavelength of the illumination light. By setting an upper limit for the average transmittance, when the wavelength band of the illumination light is narrow, for example, when the illumination light is coherent light or when the illumination light is laser, it is possible to suppress the transmission of ambient light such as sunlight through the optical filter 120, and at the same time, the illumination light can be concentratedly transmitted through the optical filter 120. As a result, illumination light of a specific wavelength band can be concentratedly transmitted through the optical filter 120. The average transmittance of the optical filter 120 in the visible light band other than the 30 nm band centered on the peak wavelength of the illumination light may be 1% or less, 0.1% or less, or 0.01% or less.

[0252] A lower limit may also be set for the average transmittance of the optical filter 120 in the visible light band other than the 30 nm band centered on the peak wavelength of the illumination light. By setting a lower limit for the average transmittance, the relative position of the projection pattern 90 with respect to the surrounding environment can be grasped through the optical filter 120 even when the amount of ambient light is small, such as at night. Thus, the processing of the optical filter 120 can be made the same between the case where the projection surface 95 is brighter and the case where the projection surface 95 is darker, and the projection pattern 90 can be clearly observed through the optical filter 120 in both cases. The average transmittance of the optical filter 120 in the visible light band other than the 30 nm band centered on the peak wavelength of the illumination light may be 0.001% or more, 0.005% or more, or 0.01% or more.

[0253] The average transmittance of the optical filter 120 in the visible light band other than the 30 nm band centered on the peak wavelength of the illumination light may be 0.001% or more and 1% or less.

[0254] As described above, when multiple upper limit candidates and multiple lower limit candidates are listed for the numerical range of transmittance, half maximum full width, illuminance, etc., the numerical range can also be constructed by combining any upper limit candidate with any lower limit candidate.

[0255] The optical filter 120 is not particularly limited as long as it has wavelength selective transmittance. The optical filter 120 may include a dielectric multilayer film 122. The dielectric multilayer film 122 is excellent in that the degree of freedom in designing the transmittance characteristics is high.

[0256] Figure 7B2 is a cross-sectional view showing an example of the layer structure of the optical filter 120 . Figure 7B The optical filter 120 shown includes: a first protective layer and a second protective layer; and a dielectric multilayer film 122 located between the first protective layer 121A and the second protective layer 121B.

[0257] The dielectric multilayer film 122 may also include alternately stacked low refractive index layers 122a and high refractive index layers 122b. The low refractive index layers 122a and high refractive index layers 122b may be inorganic layers containing inorganic compounds. The low refractive index layers 122a and high refractive index layers 122b may be resin layers.

[0258] For a dielectric multilayer film including an inorganic layer, for example, a high refractive index inorganic layer and a low refractive index inorganic layer are alternately stacked by using a CVD method, a sputtering method, a vacuum evaporation method or a wet coating method. The thickness of the multilayer film of the inorganic compound can be 0.5 μm or more and 10 μm or less. The refractive index of the inorganic compound contained in the high refractive index inorganic layer can be 1.7 or more and 2.5 or less. As the inorganic compound contained in the high refractive index inorganic layer, examples can be given of titanium oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide, indium oxide as the main component and a small amount of inorganic compounds containing titanium oxide, tin oxide, cerium oxide, etc. The refractive index of the inorganic compound contained in the low refractive index inorganic layer can be 1.2 or more and 1.6 or less. As the inorganic compound contained in the low refractive index inorganic layer, examples can be given of silicon dioxide, aluminum oxide, lanthanum fluoride, magnesium fluoride, sodium aluminum hexafluoride, etc.

[0259] The dielectric multilayer film 122 including the resin layer may also include multiple layers of thermoplastic resin or thermosetting resin. Various additives may be added to the resin layer, such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, viscosity reducers, thermal stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, dopants for adjusting the refractive index, etc. The difference in the average refractive index in the plane between the high refractive index resin layer with a high refractive index and the low refractive index resin layer with a low refractive index may be greater than 0.03, greater than 0.05, or greater than 0.1.

[0260] The number of stacking of the high refractive index resin layer and the low refractive index resin layer is adjusted according to the reflection characteristic or transmission characteristic required by the optical filter 120. For example, the high refractive index resin layer and the low refractive index resin layer can be alternately stacked more than 30 layers, or more than 200 layers can be stacked respectively. In addition, the total number of stacking of the high refractive index resin layer and the low refractive index resin layer can be, for example, more than 600 layers.

[0261] Examples of a method for producing a multilayer film of resins constituting the dielectric multilayer film include a coextrusion method, etc. Specifically, reference may be made to a method for producing a laminated film described in Japanese Unexamined Patent Application Publication No. 2008-200861.

[0262] The first protective layer 121A and the second protective layer 121B may also include 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.

[0263] The dielectric multilayer film 122 allows light of a specific wavelength band to pass through, and reflects light of a wavelength band other than the specific wavelength band. Ambient light that passes through the optical filter 120 and enters the space between the eyes of the observer 5 and the optical filter 120 travels toward the eyes of the observer. On the other hand, ambient light that enters the space between the eyes of the observer 5 and the optical filter 120 from the side can enter the surface of the optical filter 120 facing the observer 5 and be reflected at a high reflectivity. Due to this reflection, the surface of the optical filter 120 facing the observer 5 becomes mirror-like, and the visibility of the projection pattern 90 is reduced. As described above, it is also possible to suppress ambient light such as sunlight from entering the space between the eyes of the observer 5 and the optical filter 120 by bringing the optical filter 120 into contact with the face of the observer 5. It is also possible to suppress ambient light such as sunlight from entering the space between the eyes of the observer 5 and the optical filter 120 from the side by using the light-shielding wall portion 105. The average transmittance of the light-shielding wall portion 105 in the visible light band can be 0%.

[0264] Next, the operation when the projection system 10 and the observation assisting device 100 are used will be described.

[0265] like Figure 1 As shown, the lighting device 30 emits illumination light. The illumination light is irradiated to the illuminated area 96 of the projection surface 95. The observer 5 can observe the 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 can also display various information.

[0266] For example, the projection pattern 90 may also show the work target area to the observer 5 who is performing the work. The operator as the observer 5 can use the projection pattern 90 when drawing white lines or orange lines on roads, sidewalks, and parking lots, for example. Not limited to this example, the projection pattern 90 may also display the direction of arrows, etc. According to this example, the projection pattern 90 may also display a moving path or an evacuation path. In addition, the projection pattern 90 may also be text, numbers, etc. According to this example, the required information can be directly shown to the observer 5. Furthermore, the projection pattern 90 may also be an advertisement.

[0267] However, due to the ambient light of the environment in which the lighting device 30X is used, the contrast of the projection pattern 90X is reduced. At this time, the observer 5X cannot clearly observe the projection pattern 90X on the projection surface 95X. Fig.25 As shown, when the amount of ambient light such as sunlight is large, the illuminance (lx) on the projection surface 95X becomes high. The contrast of the projection pattern 90X projected onto the projection surface 95X is significantly reduced. The observer 5X cannot accurately observe the shape of the projection pattern 90X. Furthermore, the observer 5X will not even notice the existence of the projection pattern 90X on the projection surface 95X.

[0268] In the present embodiment, the projection system 10 includes an observation auxiliary device 100 in addition to the lighting device 30. The observation auxiliary device 100 includes an optical filter 120. The average transmittance of the optical filter 120 in the wavelength band of the illumination light emitted from the lighting device 30 is higher than the average transmittance of the optical filter 120 in the visible light band other than the wavelength band of the illumination light. By observing the projection pattern 90 through the optical filter 120, the brightness of the ambient light can be suppressed while maintaining the brightness of the projection pattern 90. As a result, the contrast of the projection pattern 90 can be improved, so that the projection pattern 90 can be clearly observed.

[0269] In Figure 2~ Figure 5 In the example shown, the observation auxiliary device 100 includes a wearing member 104. When the observer 5 wears the wearing member 104, the optical filter 120 faces the eyes of the observer 5. That is, the observer 5 can observe the projection pattern 90 and the projection surface 95 through the optical filter 120 by wearing the wearing member 104. Since the optical filter 120 can be held without hands, the observer 5 can use both hands freely while clearly observing the projection pattern 90. For example, the observer 5 can stably perform operations while clearly observing the projection pattern 90.

[0270] Figure 2A to Figure 2C The wearing member 104 shown may be glasses, sunglasses or goggles. The wearing member 104 shown includes a light shielding wall portion 105 located around the optical filter 120. When the observer 5 wears the wearing member 104, the light shielding wall portion 105 is located between the optical filter 120 and the observer 5. By making the light shielding wall portion 105 block ambient light, it is possible to suppress ambient light from entering the space between the optical filter 120 and the observer 5 from the side. Therefore, when using a reflective optical filter 120, it is possible to suppress the visibility of the projection pattern 90 from being reduced due to the reflection of ambient light on the optical filter 120.

[0271] Figure 5The wearing member 104 shown is a contact lens. In this example, the observer 5 can also hold the optical filter 120 without using his hands. Therefore, the observer 5 can freely use both hands 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 situation where ambient light is incident on the surface of the optical filter 120 facing the eyes of the observer 5 and is reflected.

[0272] exist Fig.15 In the example shown, the optical filter 120 constitutes the windshield 81 of the moving body 80. In this example, the observer 5 can also hold the optical filter 120 without using his hands. Fig.15 In the illustrated example, the observer 5 rides on the moving object 80 and operates the moving object 80 .

[0273] exist Figure 6 In the example shown, the observation assisting device 100 includes an imaging device 101. The imaging device 101 captures the projection pattern 90 via an optical filter 120. The imaging device 101 significantly reduces ambient light through the optical filter 120 and captures the projection pattern 90 and its surroundings. Therefore, the projection pattern 90 can be clearly observed by using the imaging device 101. Figure 6 In the example shown, the observation support device 100 includes a display device 102 electrically connected to the imaging device 101. The display device 102 displays the image captured by the imaging device 101, that is, the projection pattern 90. The projection pattern 90 with improved contrast is displayed on the display device 102. The observer 5 can clearly observe the projection pattern 90 displayed by the display device 102.

[0274] As described above, the average transmittance of the optical filter 120 in the wavelength band 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 wavelength band may be 50% or more, 70% or more, or 80% or more. The wavelength band of the illumination light emitted from the illumination device 30 may also include a wavelength at which the transmittance in the optical filter 120 is the 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. Thus, the projection pattern 90 can be clearly observed.

[0275] The average transmittance of the optical filter 120 in the visible light band outside the wavelength band 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 the visible light band outside the wavelength band of 30 nm 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 ambient light such as sunlight from passing through the optical filter 120. As a result, the contrast of the projection pattern 90 is improved, and the projection pattern 90 can be clearly observed.

[0276] The full width at half maximum FWHM of the spectral transmittance of the optical filter can be less than 15nm, less than 3nm, or less than 1nm. According to this example, when observing through the optical filter 120, it is possible to reduce ambient light while maintaining the brightness of the projection pattern 90. As a result, the contrast of the projection pattern 90 is improved, and the projection pattern 90 can be clearly observed. The full width at half maximum FWHM of the spectral transmittance of the optical filter can also include the entire domain of the wavelength band of the illumination light emitted from the illumination device 30.

[0277] The average transmittance of the optical filter 120 in the visible light band outside the band 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 the visible light band outside the band of 30 nm 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 small, such as at night, the relative position of the projection pattern 90 relative to the surrounding environment can be grasped through the optical filter 120. For example, the processing of the optical filter 120 can be the same between the case where the projection surface 95 is brighter and the case where the projection surface 95 is darker, and the projection pattern 90 can be clearly observed in both cases.

[0278] A lower limit may be set for the maximum value of the illuminance of the projection pattern 90 projected onto the projection surface 95. Here, the "illuminance of the projection pattern 90 projected onto the projection surface 95" refers to the illuminance on the projection surface 95 caused only by the illumination light emitted from the lighting device 30. Therefore, the difference between the illuminance measured at a certain position on the projection surface 95 in a state where the projection pattern 90 is projected and the illuminance measured at the same position on the projection surface 95 in a state where the projection pattern 90 is not projected is the "illuminance of the projection pattern 90 projected onto the projection surface 95". By setting a lower limit for the maximum value of the illuminance of the projection pattern 90, the projection pattern 90 can be observed brightly and clearly. The maximum value of the illuminance of the projection pattern 90 projected onto the projection surface 95 may be 1 lx or more, 0.1 lx or more, or 0.01 lx or more.

[0279] An upper limit may also be set for the maximum value of the illumination of the projection pattern 90 projected onto the projection surface 95. If the illumination of the projection pattern 90 is too high, the visibility of the projection pattern 90 cannot be effectively improved, and the energy efficiency deteriorates. From this point of view, the maximum value of the illumination of the projection pattern 90 projected onto the projection surface 95 may be 10000 lx or less, 1000 lx or less, 100 lx or less, or 10 lx or less.

[0280] The maximum value of the illuminance of the projection pattern 90 projected onto the projection surface 95 is set to illuminance LX (lx). The illuminance caused by ambient light at the position on the projection surface 95 where the illuminance LX is obtained is set to 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 band of the illumination light emitted from the illumination device 30 is set to transmittance TX (%). The average transmittance of the optical filter 120 in the visible light band other than the 30nm band centered on the peak wavelength of the illumination light emitted from the illumination device 30 is set to transmittance TY (%). At this time, the illuminance LX, the illuminance LY, the transmittance TX, and the transmittance TY may also satisfy the following relationship.

[0281] 0.001≤(LX·TX) / (LY·TY)

[0282] 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 0.1 or more.

[0283] The illuminance LX, the illuminance LY, the transmittance TX, and the transmittance TY may satisfy the following relationship.

[0284] (LX·TX) / (LY·TY)≤10

[0285] According to this example, it is possible to suppress the area around the projection pattern 90 from becoming too dark. That is, even when the amount of ambient light is small, the relative position of the projection pattern 90 with respect to the surrounding environment can be grasped via the optical filter 120. For example, the processing of the optical filter 120 can be made the same between the case where the projection surface 95 is bright and the case where the projection surface 95 is dark, and the projection pattern 90 can be clearly observed in both cases.

[0286] The illuminance is a value measured in accordance with JIS (JIS C 1609-1: 2006) using a spectroradiometer CL-500A manufactured by Konica Minolta. The measurement wavelength is 380 nm to 780 nm. The measurement wavelength interval is 1 nm. The illuminometer is placed on the projection surface 95 for measurement.

[0287] Next, the specific structure of the lighting device 30 will be described.

[0288] like Figure 8 As shown, the lighting 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 also emit coherent light with a constant wavelength and phase. The coherent light emitted from the light source 40 has excellent straightness. Therefore, the light source 40 is suitable for a lighting device 30 that illuminates a distant place. As the light source 40, various types of light sources can be used. As the light source 40, a laser light source that oscillates laser light can also be used. As the laser light source, a semiconductor laser light source can be exemplified. In Figure 8 In the example shown, the light source 40 comprises a single coherent light source. Figure 8 In the example shown, the illumination area 96 is illuminated by coherent light of a color corresponding to the wavelength band of the coherent light oscillated from the light source 40. Hereinafter, an example in which the light source 40 emits coherent light will be described.

[0289] 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 on the cross section perpendicular to the optical axis and the three-dimensional shape of the illumination coherent light. The shaping optical system 45 may also enlarge the cross-sectional area of ​​the coherent light on the cross section perpendicular to the optical axis of the coherent light.

[0290] exist Figure 8 In the example shown, 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. Figure 8In the example shown, the shaping optical system 45 has a first lens 46 and a second lens 47 arranged along the optical path. The first lens 46 shapes the light emitted from the light source 40 into a divergent beam. The second lens 47 shapes the divergent beam generated by the first lens 46 into a parallel beam. In this example, the second lens 47 functions as a collimating lens.

[0291] 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 the illuminated area 96 on the projection surface 95. The diffractive optical element 50 diffracts the coherent light from the light source 40 toward the illuminated area 96 on the projection surface 95. As a result, the diffracted light in the diffractive optical element 50 is irradiated onto the projection surface 95. The projection surface 95 is projected with a projection pattern 90 corresponding to the diffraction pattern in the diffractive optical element 50.

[0292] The diffractive optical element 50 may also be a hologram. By using a hologram as the diffractive optical element 50, it is easy to design the diffraction characteristics of the diffractive optical element 50. It is relatively easy to design a hologram that can irradiate light only to the entire area of ​​a desired area having a predetermined position, contour shape, size, and orientation on the projection plane 95. The area on the projection plane 95 irradiated with coherent light becomes the illuminated area 96.

[0293] When designing the diffractive optical element 50, the illuminated area 96 is set in the actual space at a predetermined position for 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 can be adjusted in such a way that light can be irradiated to the entire area of ​​the determined illuminated area 96.

[0294] The diffractive optical element 50 can be manufactured as a computer generated hologram (CGH). A computer generated hologram is produced by calculating a structure having arbitrary diffraction characteristics on a computer. Therefore, by using a computer generated hologram as the diffractive optical element 50, it is possible to eliminate the need to generate object light and reference light using a light source or an optical system, and eliminate the need to record interference fringes on a hologram recording material by exposure. Assume the following situation: the lighting device 30 irradiates illumination light to an illuminated area 96 of a predetermined contour shape, size, and orientation at a position predetermined for the lighting device 30. By inputting information related to the illuminated area 96 as parameters into the computer, a structure having diffraction characteristics that can project diffracted light onto the illuminated area 96, such as a concave-convex surface, can be determined by computer calculations. By forming the determined structure using, for example, resin molding, the diffractive optical element 50 as a computer generated hologram can be manufactured at low cost with simple steps.

[0295] In the design of the diffractive optical element 50, for example, an iterative Fourier transform method may be used. When the iterative Fourier transform method is used, the illumination area 96 may be processed on the premise that it is 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 not be parallel to the diffraction plane of the diffractive optical element 50.

[0296] like Fig. 9 As shown in FIG. 1 , the diffractive optical element 50 may include a plurality of element diffractive optical elements 55. Each element diffractive optical element 55 is, for example, a hologram element and can be configured in the same manner as the above-mentioned diffractive optical element 50. Fig. 9 In the example shown, the coherent light diffracted by the plurality of element diffractive optical elements 55 is irradiated to the same illuminated area 96. That is, the light diffracted by each element diffractive optical element 55 is irradiated to the entire illuminated area 96 on the projection surface 95. According to such a diffractive optical element 50, the light directed to each position in the illuminated area 96 can be emitted in a dispersed manner from the plurality of element diffractive optical elements 55 included in the diffractive optical element 50. Thus, it is possible to suppress the situation where each position on the diffractive optical element 50 becomes too bright, and the laser safety can be improved.

[0297] Each element diffractive optical element 55 may also be configured to have the same diffraction characteristics as each other. However, in order to achieve higher precision illumination, each element diffractive optical element 55 may also be given a separately designed diffraction characteristic according to the configuration position of the element diffractive optical element 55 in the diffractive optical element 50. According to this example, each element diffractive optical element 55 adjusts the diffraction characteristic according to the configuration difference with other element diffractive optical elements 55, thereby enabling the diffracted light of the light to be directed only to the entire area of ​​the illuminated area 96 on the projection surface 95 with high precision.

[0298] However, according to the lighting device 30 having the light source 40 that emits coherent light and the diffractive optical element 50 that diffracts the coherent light, it is possible to illuminate a large area of ​​the illuminated area 96 or an illuminated area 96 that extends to a position away from the lighting device 30 on the projection plane 95. That is, it is possible to project a long and narrow projection pattern 90 onto the projection plane 95. At this time, the incident angle α at which the coherent light is incident on each position in the illuminated area 96 has a large deviation. The incident angle α incident on the illuminated area 96 away from the lighting device 30 is very large, for example, close to 90°. The diffraction surface of the diffractive optical element 50 forms a large angle with respect to the projection plane 95 and the illuminated area 96. Here, the incident angle α incident on the illuminated area 96 refers to the angle formed by the traveling direction of the illumination light relative to the normal direction ND of the illuminated area 96. In the example shown in the figure, the normal direction ND is parallel to the third direction D3, wherein the third direction D3 is perpendicular to both the first direction D1 and the second direction D2.

[0299] In the lighting 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 toward the illuminated area 96 of the desired shape by the diffractive optical element 50. Therefore, the relative position with respect to the lighting device 30 is not strongly constrained, for example, the illuminated area 96 can be set at a position away from the lighting device 30, or at a position where the incident angle α of the coherent light becomes larger. That is, the degree of freedom in setting the projection pattern 90 and the projection surface 95 can be greatly improved. As a result, the coherent light can be irradiated to the illuminated area 96 with high accuracy. The projection pattern 90 can be accurately projected onto the projection surface 95.

[0300] As an example, according to the diffractive optical element 50 composed of a computer-generated hologram, the traveling direction of the coherent light incident from a certain direction can be adjusted with an accuracy of ±0.01° in the angle space. By using such a diffractive optical element 50, it is possible to illuminate the illuminated area 96 at a distance of more than 1m and less than 120m from the diffractive optical element 50 with high accuracy, or the illuminated area 96 at which the incident angle α of the coherent light incident on the illuminated area 96 is at least 30° and at most 89.99°. Therefore, the lighting device 30 can irradiate the illuminated area 96 located on the projection surface 95 with coherent light with high accuracy. As a result, the edge of the projection pattern 90 can be clearly identified, and the operator can observe the projection pattern 90 located far away.

[0301] Fig.10 A specific configuration example of the lighting device 30 is shown. Fig.10 The lighting device 30 shown is portable. Fig.10 The lighting device 30 shown can be carried by an operator without using a special mechanism. The lighting device 30 has a housing 70. Fig.10 In the lighting device 30 shown, the light source 40, the shaping optical system 45, and the diffractive optical element 50 are fixed to the housing 70. In normal use, the light source 40, the shaping optical system 45, and the diffractive optical element 50 are not accidentally removed from the housing 70. The light source 40, the shaping optical system 45, and the diffractive optical element 50 cannot be removed from the housing 70. As a result, the relative positions of the light source 40, the shaping optical system 45, and the diffractive optical element 50 are maintained. As a result, the projection pattern 90 can be projected with high precision and stably at a position on the projection surface 95 that is in a predetermined relative positional relationship with respect to the lighting device 30. In addition, the light source 40, the shaping optical system 45, and the diffractive optical element 50 can be suppressed from deviating from the predetermined position, and the laser safety can be improved.

[0302] In addition, Fig.10In the example shown, the shaping optical system 45 includes a first lens 46, a second lens 47, and a third lens 48. The housing 70 includes a cylindrical portion 71 that holds the light source 40 and the shaping optical system 45, and a cover portion 72 fixed to the cylindrical portion 71. The cylindrical portion 71 is a cylindrical shape with one side closed. The light source 40 is fixed to one of the closed ends of the cylindrical portion 71. The inner dimensions of the cylindrical portion 71 vary via a step portion 71a. The inner diameter increases from the upstream side toward 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 respectively mounted on the two step portions 71a. A spacer ring 73 capable of controlling the distance between the lenses with high precision is provided in the cylindrical portion 71. The spacer ring 73 is arranged between the first lens 46 and the second lens 47. The spacer ring 73 is arranged between the second lens 47 and the third lens 48. In addition, a spacer ring 73 is arranged between the cover portion 72 and the third lens 48. The spacer ring 73 suppresses the relative position deviation of each lens caused by vibration or impact that may be applied to the lighting device 30, etc. As an example, the spacer ring 73 can be an annular or cylindrical component. As the spacer ring 73, a metal such as aluminum can be used, or a resin can be used. In order to reduce the thermal expansion coefficient, an inorganic material such as glass fiber can also be mixed into the resin. The spacer ring 73 can suppress the parallelism deviation of the collimated light caused by the vibration or impact applied to the lighting device 30. That is, it is possible to suppress the blurring of the projection pattern 90 on the projection surface 95. As a result, the visibility of the projection pattern 90 can be maintained at a high level.

[0303] In order to maintain the relative positions of the light source 40, the shaping optical system 45, and the diffractive optical element 50 constant, the light source 40, the shaping optical system 45, and the diffractive optical element 50 may be fixed to the housing 70 by fixing with an adhesive material, or by fixing with an adhesive material in combination with embedding.

[0304] For example, a spacer may be used to slightly correct the relative positions of the light source 40, the shaping optical system 45, and the diffractive optical element 50. As the spacer, a thinner plate-like member made of metal may be used. The spacer may also be used together with the spacer ring 73 or the adhesive material.

[0305] In addition, components such as the light source 40, the shaping optical system 45, and the diffractive optical element 50 can also be held by a position adjustment holder that can be configured for fine adjustment. Regarding the position adjustment holder, the position of the component can also be fine-tuned by operating an adjustment portion such as a screw. The component can also be fixed to the housing 70 via a position adjustment holder. When using a position adjustment holder, the adjustment portion such as a screw can also be fixed by an adhesive material after the position adjustment of the component is completed. In addition, the position adjustment holder can also be used in combination with the above-mentioned spacer ring 73 or other components for maintaining the relative position of the finely adjusted components.

[0306] The housing 70 may be designed to be non-detachable, so that the relative positions of components such as the light source 40, the shaping optical system 45, and the diffractive optical element 50 are maintained. For example, the relative positions of the components positioned by the manufacturer of the lighting device 30 may be maintained. For example, an adhesive material may be applied to the screw fastening portion or the embedded portion of the housing 70 to make the housing 70 non-detachable.

[0307] exist Fig.10 In the example shown, 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 and dischargeable secondary battery. The circuit 75 is electrically connected to the battery 74 and the switch 76. The circuit 75 for operating the switch 76 switches the power supply from the battery 74 to the light source 40 and the power cut.

[0308] The lighting device 30 may also be supplied with power from an external power source. For example, a connector for electrically connecting to an external power source may be provided on the housing. 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 has excellent resistance to vibration or impact.

[0309] The lighting device 30 and the housing 70 may also be waterproof. In order to provide the lighting device 30 with waterproof properties, waterproof members such as rubber or packing may be provided at the joint portion or the embedded portion of the housing 70 .

[0310] The lighting device 30 may also have a temperature control mechanism. The temperature control mechanism may also maintain the light source 40 and the circuit 75 at a temperature within a predetermined range. The temperature control mechanism may also heat or cool the light source 40 and the circuit 75. The temperature control mechanism may also be disposed in the housing 70. Examples of the temperature control mechanism include a fan, a heater, and a cooler. As the temperature control mechanism, a heating wire or a Peltier element may also be used.

[0311] like Fig.11As shown, the illumination device 30 may include a scanning device 60 . Fig.11 The lighting device 30 shown 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, controls the supply of the coherent light to the diffractive optical element 50, and controls the distribution of the coherent light to the plurality of diffractive optical elements 50A to 50C. The scanning device 60 can be configured using various components that can change the optical path by refraction, reflection, diffraction, etc. Examples of various components that can change the optical path include lenses, prisms, reflectors, diffractive optical elements, etc.

[0312] 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 plurality of diffractive optical elements 50A to 50C. That is, the diffractive optical element 50 on which the coherent light from the light source 40 is incident changes between the plurality of diffractive optical elements 50A to 50C. The illustrated scanning device 60 has a reflecting surface that can rotate around an axis RA. As such a scanning device 60, a galvanometer mirror can also be used.

[0313] The illuminated area 96 may also be divided into a plurality of local areas 93A, 93B, 93C according to the position in the first direction D1. A plurality of diffractive optical elements 50A to 50C may also illuminate mutually different local areas 93A, 93B, 93C. According to this example, the diffraction angle range of the light diffracted by one diffractive optical element 50 can be narrowed. Thus, the diffraction efficiency in each diffractive optical element 50 is improved. In addition, the scanning device 60 operates at a speed exceeding the visual resolution of humans, thereby making humans observe that all the local areas 93A, 93B, 93C included in the illuminated area 96 are illuminated continuously at the same time.

[0314] exist Fig.12In the example shown, the diffractive optical element 50 includes the 1st to 12th diffractive optical elements 50A to 50L. For example, the illuminated area 96 on the projection surface 95 is divided into the 1st to 12th local areas 93A to 93L. The coherent light diffracted by the 1st to 12th diffractive optical elements 50A to 50L is irradiated to each of the 1st to 12th local areas 93A to 93L. The scanning device 60 directs the light from the light source 40 toward each of the diffractive optical elements 50A to 50L. The lighting device 30 can control whether or not to irradiate each of the diffractive optical elements 50A to 50L with light according to the operation of the scanning device 60. For example, the light source 40 switches the emission of light and the stop of emission according to the operation of the scanning device 60. As another example, according to the operation of the scanning device 60, a light shielding component that blocks light enters the optical path of the light from the light source 40 and retreats from the optical path. By controlling whether or not to irradiate the diffractive optical elements 50A to 50L with light, coherent light can be projected only to any diffractive optical element 50A to 50L. Thus, only any first to twelfth partial regions 93A to 93L can be illuminated, and the illuminated region 96 can be illuminated in a desired shape.

[0315] in addition, Fig.11 and Fig.12 The diffractive optical element 50 included in the illustrated illumination device 30 may also be divided into a plurality of elemental diffractive optical elements 55 .

[0316] In one 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 a projection pattern 90 onto a projection surface 95. The average transmittance of the optical filter 120 in the wavelength band 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 band other than the wavelength band of the illumination light. According to this embodiment, by observing the projection pattern 90 through the optical filter 120, the contrast of the projection pattern 90 on the projection surface 95 is improved. Thus, the projection pattern 90 can be clearly observed.

[0317] In one embodiment described above, the observation assisting device 100 assists in the observation of the projection pattern 90 projected onto the projection surface 95 using the illumination light emitted from the illumination device 30. The observation assisting device 100 includes an optical filter 120. The average transmittance of the optical filter 120 in the wavelength band 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 band other than the wavelength band of the illumination light. The wavelength band of the illumination light is a wavelength that is 5 nm lower than the peak wavelength of the illumination light and 5 nm higher than the peak wavelength. The peak wavelength of the illumination light is a wavelength at which the maximum radiation flux of the illumination light can be obtained. According to the present embodiment, by observing the projection pattern 90 through the optical filter 120, the contrast of the projection pattern 90 on the projection surface 95 can be improved. Therefore, by supporting the observation of the projection pattern 90 by the observation assisting device 100, the projection pattern 90 can be clearly observed.

[0318] One embodiment has been described with reference to a specific example, but the above specific example does not limit the one embodiment. The above one embodiment can be implemented with various other specific examples, and various omissions, substitutions, changes, additions, etc. can be made without departing from the scope of the gist thereof.

[0319] In the following description and the drawings used in the following description, for parts that can be configured in the same manner as the above-mentioned specific example, the same reference numerals as those used for corresponding parts in the above-mentioned specific example are used, and repeated descriptions are omitted.

[0320] In the above-mentioned specific example, an example is shown in which the observation support device 100 includes the imaging device 101 and the display device 102. Fig.13 As shown, the imaging device 101 of the observation support device 100 may also be mounted on the moving body 80. When the projection pattern 90 projected onto the projection surface 95 by the lighting device 30 indicates the moving path of the moving body 80, the observer 5 can operate the moving body 80 while observing the image displayed on the display device 102.

[0321] Fig.14 1 is a top view showing a display surface 103 of a display device 102. The imaging device 101 captures a projection surface 95 which is a road surface. A linear projection pattern 90 is projected onto the projection surface 95. The observer 5 can manipulate the moving body 80 while observing the image displayed on the display surface 103. Thus, the moving body 80 can move along a predetermined movement path indicated by the projection pattern 90.

[0322] like Fig.14As shown, the display device 102 may also display the reference pattern 97 together with the image captured by the camera device 101. The reference pattern 97 may also indicate a predetermined position, a predetermined direction, or a predetermined range within the range captured by the camera device 101. The predetermined position, the predetermined direction, or the predetermined range may also be a position, a direction, or a range on the projection surface 95.

[0323] exist Fig.14 In the example shown, the reference pattern 97 indicates a planned movement path 99A of the moving body 80 when the moving body 80 maintains the current driving. 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 the direction in which the moving body 80 moves within the imaging range of the imaging device 101.

[0324] according to Fig.14 In the example shown, the moving body 80 can be moved along the predetermined moving path with high accuracy by overlapping the reference pattern 97 and the projection pattern 90 indicating the predetermined moving path 99A on the display surface 103 of the display device 102. In addition, by observing the overlap of the reference pattern 97 and the projection pattern 90 indicating the predetermined moving path 99A on the display surface 103 of the display device 102, it can be confirmed that the moving body 80 moves along the predetermined moving path.

[0325] In addition, the camera device 101 may be mounted on the moving body 80. In this example, the camera device 101 can display an image of an area in a certain relative relationship with the moving body 80. When the moving body 80 moves in a certain manner such as moving straight, it passes through a certain position within the range displayed by the display device 102 of the camera device 101. The reference pattern 97 indicating the planned movement path 99A of the moving body 80 may be an image input as image data to the display device 102 and displayed on the display device 102, or may be a mark on the display surface 103 with a writing tool or a mark.

[0326] The mobile body 80 may also be a work vehicle for performing certain operations. The mobile body 80 may also perform certain operations while moving. Fig.17 In the example shown, the mobile body 80 includes a working device 84. The working device 84 can perform a predetermined operation on the traveling surface of the mobile body 80, that is, the projection surface 95. As described above, the working device 84 can also be used for line marking operations. In the line marking operation, for example, a white line or an orange line can be drawn on the work target surface such as a road, a sidewalk, or a parking lot.

[0327] In the example where the moving body 80 is a work vehicle, the projection pattern 90 may also indicate the position where the work is to be performed on the projection surface 95, the direction where the work is to be performed on the projection surface 95, and the area where the work is to be performed on the projection surface 95. Fig.14 In the example shown, the projection pattern 90 may be a predetermined path along which work should be performed.

[0328] exist Fig.14 In the example shown, the reference pattern 97 may indicate a planned work path 99B for performing work using the mobile body 80 when the mobile body 80 as the work vehicle maintains the current travel. That is, the reference pattern 97 may indicate a planned work position of the mobile body 80 within the imaging range of the imaging device 101. The reference pattern 97 may also indicate a direction in which the mobile body 80 advances the work within the imaging range of the imaging device 101.

[0329] according to Fig.14 In the example shown, the work using the moving body 80 can be performed along the planned work path with high accuracy by overlapping the reference pattern 97 indicating the planned work path 99B with the projection pattern 90 on the display surface 103 of the display device 102. In addition, by observing the overlap of the reference pattern 97 indicating the planned work path 99B with the projection pattern 90 on the display surface 103 of the display device 102, it can be confirmed that the work using the moving body 80 is performed along the planned work path.

[0330] However, there are cases where it is difficult to see the projection pattern on the projection surface, depending on environmental conditions such as weather. In addition, in order to brightly display a large-area projection pattern, it is necessary to increase the output of the lighting device. In this case, the emission end of the lighting device becomes dazzling. Fig.18A In the example shown, the projection pattern 90 is linear. The linear projection pattern 90 is easily displayed brightly at a position close to the lighting device 30 on the projection surface 95. The linear projection pattern 90 is displayed darkly at a position far from the lighting device 30 on the projection surface 95. The linear projection pattern 90 may be difficult to observe at a position far from the lighting device 30 on the projection surface 95.

[0331] In order to cope with such an inconvenience, the projection system 10 and the observation support device 100 may have the following configuration.

[0332] like Fig.17 As shown, the projection system 10 and the observation support 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.

[0333] The control device 130 generates a display pattern 92 associated with the detected projection pattern. The display device 102 displays the display pattern 92 in a superimposed manner on the image captured by the imaging device 101 .

[0334] Fig.18A Shows Fig.17 The projection system 10 and the display surface 103 of the display device 102 of the viewing aid 100 are shown. Fig.17 In the illustrated example, the lighting device 30 projects the projection pattern 90 which is a linear pattern onto the projection surface 95. The linear pattern extends linearly between the lighting device 30 and the imaging device 101 along the first direction D1.

[0335] exist Fig.18A and the following references Figures 18B to 18E In the example shown, the projection surface 95 is a road. The road is connected to other roads to form a T-intersection. The projection pattern 90 extends linearly along the road from the T-intersection. Fig.18A In the example shown, a linear projection pattern 90 is observed near a T-intersection far from the imaging device 101 .

[0336] exist Fig.18B In the example shown, the display device 102 displays a display pattern 92 superimposed on the image captured by the imaging device 101. The display pattern 92 includes a linear auxiliary pattern 93 extending on the extension line of the projection pattern 80. Fig.18B In the example shown, 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.

[0337] exist Fig.18B In the example shown, the display device 102 displays the projection pattern 90 and the connected auxiliary pattern 93 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.

[0338] The display device 102 displays the auxiliary pattern 93 generated by the control device 130, so that the entire projection pattern 90 that is partially difficult to see depending on environmental conditions, etc. can be clearly seen. Thus, a predetermined movement or work can be stably performed based on the information shown by the projection pattern 90.

[0339] In addition, the projection pattern 90 may also be a part of the pattern originally intended to be displayed, provided that the auxiliary pattern 93 of the display pattern 92 is used. The illuminated area 96 may also be a part of the pattern originally intended to be displayed. In this example, the display pattern 92 is displayed in an area other than the illuminated area 96 on the display surface 103. According to this example, the output of the lighting device 30 can be reduced, and the irradiation end 31 of the lighting device 30 can be suppressed from becoming dazzling.

[0340] The control device 130 may also include a CPU (Central Processing Unit) that operates based on a predetermined program. The control device 130 may also include an input unit such as a keyboard and a mouse. The control device 130 may also include a storage unit such as a ROM and a RAM. The control device 130 may also include a storage unit such as a semiconductor drive such as an SSD. The control device 130 may also include a storage unit such as a cloud server.

[0341] The control device 130 may also communicate with the camera 101 by wireless or wired means. The control device 130 may also obtain image data captured by the camera 101 from the camera 101. The control device 130 may also detect the projection pattern 90 using the image data obtained from the camera 101. The control device 130 may also communicate with the display device 102 by wireless or wired means. The control device 130 may also control the display content of the display device 102. The display device 102 may also be a display device such as a liquid crystal display, a plasma display, an organic EL display, etc. The display device 102 may also include a touch panel sensor that functions as an input unit.

[0342] Fig.19 This is a flowchart related to the processing of the control device 130. Fig.19 The flowchart shown shows an example of a method for detecting the projection pattern 90 from the image obtained by the imaging device 101 and generating the auxiliary pattern 93 of the display pattern 92. In this example, the linear projection pattern 90 is detected, and the image data of the auxiliary pattern 93 located on the extension line of the projection pattern 90 is generated.

[0343] exist Fig.19 In the example shown, through steps S1 to S6 , the auxiliary pattern 93 of the display pattern 92 is generated.

[0344] First, as the first step S1, the processing region R130 is determined by trimming. In order to reduce the amount of calculation and the calculation time, only the image data displayed in the local area of ​​the display surface 103 is used as the processing object of the control device 130. This local area becomes the processing region R130 (see Fig.18A The processing region R130 may be set in advance. The processing region R130 may be set each time by the observer 5 who observes the display device 102.

[0345] As the second step S2, only a specific wavelength component is extracted from the image data captured by the imaging device 101. The extracted specific wavelength may be a wavelength band of the illumination light emitted from the illumination device 30. The extracted specific wavelength may also be a wavelength band of 30 nm centered on the peak wavelength of the illumination light. In the case where the image data captured by the imaging device 101 is a monochrome image, the second step S2 is not necessary.

[0346] As the third step S3, the image obtained in the second step is smoothed. A Gaussian filter or the like is used to remove high-frequency components from the image data.

[0347] As the fourth step S4, a group of points constituting the projection pattern 90 is searched. Each point may be regarded as a pixel of the display device 102. In the example of detecting the linear projection pattern 90, a group of points constituting the projection pattern 90 may be searched as follows.

[0348] First, the Y direction as the longitudinal direction and the X direction as the lateral direction are defined according to the pixel arrangement of the display device 102. The pixel with the maximum brightness is selected from the plurality of pixels arranged in the X direction and belonging to the top row in the Y direction. The selected pixel is used as a candidate for the point group constituting the projection pattern 90. The brightness of the pixel is evaluated by the grayscale of the pixel.

[0349] Next, a pixel with the maximum brightness is selected from a plurality of pixels arranged in the X direction and in the next row in the Y direction of the row in which the point group candidate was initially selected. The selected pixel is compared with the offset in the X direction of the pixel initially selected as the point group candidate and a preset column threshold. When the offset is less than the column threshold, the selected pixel is determined to be a candidate for the point group constituting the projection pattern 90. Thereafter, a pixel with the maximum brightness is searched for from a plurality of pixels arranged in the X direction and in the next row in the Y direction of the row in which the point group candidate was last selected.

[0350] When the offset in the X direction between the pixel selected as the pixel with the maximum brightness and the pixel selected as the point group candidate immediately before is greater than the column threshold, the last selected pixel does not enter the point group candidate. Next, the number of pixels selected as point group candidates, in other words, the number of continuous rows in the Y direction for obtaining the point group candidates is compared with a preset row threshold. When the number of rows is greater than the row threshold, the pixels selected as point group candidates are determined to be the point group constituting the projection pattern 90.

[0351] When the number of rows is less than the row threshold, the previously selected pixel is deleted from the point group candidates. Then, the search for new point group candidates starts from the row next in the Y direction to the row where the pixel with the maximum brightness was last selected by the above method.

[0352] As described above, the point group constituting the projection pattern 90 is searched. The above processing is implemented for each image data captured by the camera 101, for example, each image data acquired at 10 frames / second. For image data that does not meet the row threshold condition, it is determined that there is no point group constituting the projection pattern 90, that is, there is no projection pattern 90.

[0353] As a fifth step S5, the projection pattern 90 is determined from the point group constituting the projection pattern 90. The least square method may be used to determine the linear projection pattern 90. The "FitLine" of the image processing software "OpenCV" may be used to determine the linear projection pattern 90. The projection pattern 90 may also be determined within the range of the row in the Y direction including the point group constituting the projection pattern 90.

[0354] As the sixth step S6, an auxiliary pattern 93 is generated. In the fifth step, the position of the projection pattern 90 is determined as a function in an orthogonal coordinate system with the X direction and the Y direction as axes. The auxiliary pattern 93 is determined as a function having the same slope as the projection pattern 90. The auxiliary pattern 93 is determined as a function connected 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.

[0355] Thereby, the position of the auxiliary pattern 93 on the image captured by the imaging device 101 is identified.

[0356] like Fig. 18C As shown, the display pattern 92 may also include a detection pattern 94. The detection pattern 94 is displayed overlapping with 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 in the display device 102. According to such an example, the projection pattern 90 can be brightly observed on the display surface 103 of the display device 102 regardless of environmental conditions. As a result, the predetermined movement or operation can be stably performed according to the information shown by the projection pattern 90.

[0357] like Fig. 18C As shown, the display pattern 92 may include both the auxiliary pattern 93 and the detection pattern 94. In this example, the auxiliary pattern 93 may be connected to the detection pattern 94. The auxiliary pattern 93 may also be located on the extension line 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 may be clearly observed on the display surface 103 of the display device 102 regardless of the environmental conditions. Thus, the predetermined movement or operation can be stably performed according to the information shown in the projection pattern 90.

[0358] like Fig. 18C As shown, the auxiliary pattern 93 and the detection pattern 94 may also be displayed in different patterns. Fig.18D As shown, the auxiliary pattern 93 and the detection pattern 94 may also be displayed in the same pattern. Fig.18D As shown, the display pattern 92 may include the auxiliary pattern 93 and the detection pattern 94 as one continuous pattern.

[0359] exist FIG. 18A to FIG. 18DIn the example shown, the display device 102 displays the reference pattern 97. As described above, 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 reference pattern 97 may also indicate a planned movement path 99A of the mobile body 80. The reference pattern 97 may also indicate a planned operation position or a planned operation path 99B of the operation device 84 of the mobile body 80.

[0360] The control device 130 may also evaluate the positional relationship of the detected projection pattern 90 relative to the reference pattern 97. The control device 130 may also evaluate the positional relationship of the generated display pattern 92 relative to the reference pattern 97. The control device 130 may also evaluate the positional relationship of the generated auxiliary pattern 93 relative to the reference pattern 97. The control device 130 may also evaluate the positional relationship of the generated detection pattern 94 relative to the reference pattern 97.

[0361] In the above example, the positional offset of each pattern 90, 92, 93, 94 on the display surface 103 of the display device 102 and the reference pattern 97 refers to the actual movement path, passing position, working path and working position of the movable body 80 being offset from the predetermined movement or working path, or position.

[0362] For example, the control device 130 may determine that an "abnormality" exists when the difference in positional relationship between the patterns 90, 92, 93, 94 and the reference pattern 97 in the above-mentioned orthogonal coordinate system with the X and Y directions as axes is greater than a certain value.

[0363] More specifically, the presence or absence of an abnormality may be evaluated based on whether the difference or ratio of the slopes of the two compared patterns is within a specified range. The presence or absence of an abnormality may be evaluated based on whether the difference in the X coordinates at a certain Y coordinate of the two compared patterns is within a specified range. The presence or absence of an abnormality may be evaluated based on whether the difference in the Y coordinates at a certain X coordinate of the two compared patterns is within a specified range. The presence or absence of an abnormality may be evaluated based on whether the sum of the difference in the X coordinates at a certain Y coordinate of the two compared patterns and the difference in the Y coordinates at a certain X coordinate of the two compared patterns is within a specified range. The presence or absence of an abnormality may also be evaluated based on the distance between the two compared patterns.

[0364] Alternatively, the control device 130 may report an abnormality when determining that the positional relationship between the detected or generated patterns 90, 92, 93, 94 and the reference pattern 97 is abnormal. By reporting the abnormality, the position or orientation of the moving body 80 is corrected. For example, Fig.18EAs shown, the position or orientation of the moving body 80 is corrected so that the detected or generated patterns 90, 92, 93, 94 overlap with the reference pattern 97. Thus, the work of moving the moving body 80 or the work of using the moving body 80 can be performed according to the information displayed by the projection pattern 90.

[0365] The control device 130 may also notify the observer 5 of the abnormality through a display, sound, etc. output from the display device 102. For example, the display method of the image captured by the camera device 101 may be changed in the case of an abnormality. In the case of an abnormality, the display method of the display pattern 92 may be changed in the camera device 101. In the case of an abnormality, the display method of the reference pattern 97 may be changed in the camera device 101. The control device 130 may also display a warning on the display device 102.

[0366] like Fig.17 As shown, the projection system 10 and the observation auxiliary device 100 may also include a reporting device 86 for reporting an abnormality. The reporting 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 reporting device 86 may also use at least one of light and sound to report the abnormality.

[0367] The control device 130 may also report an abnormality by changing the projection method of the projection pattern 90 toward the projection surface 95. In this example, the control device 130 is electrically connected to the lighting device 30. The control device 130 may also send a control signal to the lighting device 30 by wire or wireless when an abnormality is detected, and 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 band of the illumination light, and a switch between lighting and flashing.

[0368] exist Fig.17 In the example shown, the observer 5 presses the moving body 80, so that the moving body 80 moves. While the moving body 80 moves, the working device 84 works on the projection surface 95. The moving body 80 is not limited to a working vehicle for drawing lines on the projection surface 95. In addition, the moving body 80 may also move while the observer 5 is riding on it.

[0369] The mobile body 80 may be a work vehicle for making roads or sidewalks, a work vehicle for repairing roads or sidewalks, a work vehicle for performing agricultural operations, or a work vehicle for preparing fields. Examples of the mobile body 80 for making or preparing roads, etc., include a grader, an asphalt finisher, a load roller, a tire roller, a wheel loader, a mixing vehicle, a line striping vehicle, a snowplow, a sweeper, etc. Examples of the mobile body 80 for performing agricultural operations and the mobile body 80 for preparing fields include a rice transplanter, a harvester, a mower, a tractor, a drug spreading vehicle, a tiller, etc. The mobile body 80 may also be a special vehicle or an industrial vehicle specified by ISO5053-1.

[0370] like Fig. 20 As shown, the observer 5 can also use the remote control device 87 to control the moving body 80 while observing the display device 102. As described above, the moving body 80 can also be a train, an airplane, a ship, or a Fig.21 The drone shown. Fig.21 In the example shown, the mobile body 80 as an unmanned aerial vehicle may include a working device 84. The working device 84 mounted on the mobile body 80 as an unmanned aerial vehicle may be a spreading device.

[0371] The projection pattern 90 is not limited to a linear pattern. As described above, the projection pattern 90 can be changed. Fig. 22 and Fig.23 Modifications of the projection pattern 90 and the display pattern 92 are shown.

[0372] like Fig. 22 As shown, the projection pattern 90 may also include a first linear pattern 91A and a second linear pattern that intersect each other. The first linear pattern 91A and the second linear pattern 91B may also be orthogonal. The projection pattern 90 may also be a cross mark. The projection pattern 90 may indicate the final destination of the movement through the intersection of the first linear pattern 91A and the second linear pattern 91B, or may indicate the center of the position where the operation is to be performed.

[0373] exist Fig. 22 In the example shown, the display pattern 92 includes a first auxiliary pattern 93A and a second auxiliary pattern 93B. The first auxiliary pattern 93A is located on the extension line of the first linear pattern 91A. A pair of first auxiliary patterns 93A extend from both ends of the first linear pattern 91A. The second auxiliary pattern 93B is located on the extension line of the second linear pattern 91B. A pair of second auxiliary patterns 93B extend from both ends of the second linear pattern 91B. A larger cross mark is shown by the combination of the projection pattern 90 and the display pattern 92. The display pattern 92 can also indicate the area where the operation should be performed by combining with the projection pattern 90.

[0374] exist Fig.23In the example shown, the projection pattern 90 is a linear pattern extending on the circumference. The projection pattern 90 may also indicate the center of the area where the work is to be performed. Fig.23 Different from the examples shown, the projection pattern 90 may be a line extending on the circumference of an ellipse, a line extending along the outline of a triangle, a line extending along the outline of a quadrilateral, or a line extending along the outline of a polygon such as a pentagon or a hexagon. The projection pattern 90 may also be a circle, a triangle, a quadrilateral, or a polygon such as a pentagon or a hexagon.

[0375] exist Fig.23 In the example shown, the display pattern 92 includes an auxiliary pattern 93 that surrounds the projection pattern 90 in a surrounding shape. The auxiliary pattern 93 may be adjacent to the projection pattern 90. The auxiliary pattern 93 may also be spaced apart from the projection pattern 90 as in the example shown in the figure. The auxiliary pattern 93 spaced apart from the projection pattern 90 may also be linear. The auxiliary pattern 93 of the display pattern 92 may also indicate the area where the operation is to be performed by combining with the projection pattern 90.

[0376] The center of gravity 93Y of the area surrounded by the outer contour 93X of the auxiliary pattern 93 may be located at the same position as at least one of the center of gravity 90Y of the projection pattern 90 and the center of gravity 90Y of the area surrounded by the outer contour 90X of the projection pattern 90. Fig.23 In the example shown, the display pattern 92 includes auxiliary patterns 93 that extend along two circumferences that are arranged concentrically with the projection pattern 90. The auxiliary pattern 93, like the projection pattern 90, may be a line extending along the circumference of an ellipse, a line extending along the outline of a triangle, a line extending along the outline of a quadrilateral, or a line extending along the outline of a polygon such as a pentagon or a hexagon.

[0377] Fig.24 FIG. 1 shows a display surface 103 of the display device 102. The display device 102 displays an image captured by the camera device 101. Fig.23 The projection pattern 90 is shown. The display device 102 displays the auxiliary pattern 93 of the display pattern 92 overlapping with the image including the projection pattern 90. The display device 102 displays the reference pattern 97 overlapping with the image including the projection pattern 90. The reference pattern 97 is a cross mark.

[0378] exist Fig.24In the specific example shown, the projection surface 95 onto which the projection pattern 90 is projected is a field where crops are grown. It is assumed that pesticides, fertilizers, and other materials are spread in a predetermined spreading area of ​​the field. In this assumption, the projection pattern 90 may also represent the center of the spreading area. The auxiliary pattern 93 of the display pattern 92 may also represent the range of the spreading area.

[0379] The reference pattern 97 may also indicate the position where the dispersed material is to be dispersed according to the direction of the nozzle that sprays the dispersed material. That is, the reference pattern 97 may also indicate the predetermined position where the dispersed material is to be dispersed according to the direction of the nozzle. In this example, the camera device 101 may also be installed on the nozzle. In this example, the reference pattern 97 may also be generated by the control device 130 based on the state of the working device 84.

[0380] The reference pattern 97 may include a first reference pattern 97A and a second reference pattern 97B. Fig.25 In the example shown, the first reference pattern 97A is a cross mark indicating the intended scattering position. The second reference pattern 97B is an arrow indicating the direction in which the intended scattering position moves. The moving direction of the intended scattering position indicated by the second reference pattern 97B can also be determined by processing in the control device 130 based on the operation information of the nozzle that discharges the dispersed matter.

[0381] As described above, the control device 130 detects the pattern 90 in the image displayed on the display device 102, and generates a display pattern 92 associated with 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 the 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 the control device 130 can also be applied to the observation of a pattern drawn on a surface with paint or the like.

[0382] The display device 102 and the control device 130 may be combined to display an image captured by the imaging device 101 not including the optical filter 120. In this example, the control device 130 detects a pattern from the image, thereby displaying the display pattern 92 superimposed on the image.

[0383] Description of symbols

[0384] D1: 1st direction; D2: 2nd direction; D3: 3rd direction; 5: observer; 10: projection system; 30: lighting device; 31: emission end; 40: light source; 45: shaping optical system; 46: 1st lens; 47: 2nd lens; 48: 3rd lens; 50: diffractive optical element; 55: element diffractive optical element; 60: scanning device; 70: housing; 71: cylindrical part; 71a: step part; 72: cover part; 73: spacer ring; 74: battery; 75: circuit; 76: switch; 80: moving body; 81: windshield; 82: partition member; 84: working device; 86: notification device; 90 : Projection pattern; 92: Display pattern; 93: Auxiliary pattern; 94 Detection pattern; 95: Projection surface; 96: Illuminated area; 97: Reference pattern; 100: Observation auxiliary device; 101: Camera device; 101a: Camera element; 102: Display device; 104: Wearing piece; 105: Light-shielding wall portion; 106: Frame; 106A: Frame body; 106B: Holding portion; 107: Wearing piece body; 108: Contact lens body; 120: Optical filter; 121: Base material; 122: Dielectric multilayer film; 122a: Low refractive index layer; 122b: High refractive index layer; 130: Control device.

Claims

1. A projection system, wherein: The projection system comprises: an illumination device that emits illumination light and projects a projection pattern onto a projection surface; and an optical filter having an average transmittance in the wavelength band of the illumination light higher than an average transmittance in a visible light band other than the wavelength band of the illumination light, The wavelength band of the illumination light is a wavelength band that is greater than or equal to a wavelength that is 5 nm lower than a peak wavelength of the illumination light and less than or equal to a wavelength that is 5 nm higher than the peak wavelength. The peak wavelength of the illumination light is a wavelength at which the maximum radiant flux of the illumination light can be obtained.

2. The projection system according to claim 1, wherein: In the projection system, the projected pattern is observed through the optical filter.

3. The projection system according to claim 1, wherein: The projection system includes a wearable item that can be worn by an observer of the projection pattern. The wearable device includes the optical filter, In a state where the observer wears the wearing tool, the optical filter faces the eyes of the observer.

4. The projection system according to claim 3, wherein: The wearing member includes a light shielding wall portion located around the optical filter. When the observer wears the wearing tool, the light shielding wall portion is located between the optical filter and the observer.

5. The projection system according to claim 1, wherein: The optical filter constitutes a windshield of the moving body.

6. The projection system according to claim 1, wherein: The projection system includes an imaging device including the optical filter.

7. The projection system according to claim 6, wherein: The projection system includes a display device electrically connected to the imaging device. The display device displays the image captured by the imaging device.

8. The projection system according to claim 7, wherein: The display device includes a wearing accessory that can be worn by an observer, and a display element that is held by the wearing accessory and displays the image. In a state where the observer wears the wearing tool, the display element faces the eyes of the observer.

9. The projection system according to claim 8, wherein: The total light transmittance of the display element is greater than 1%.

10. The projection system according to claim 7, wherein: The projection system includes 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 associated with the detected projection pattern. The display device displays the display pattern in an overlapping manner with the image.

11. The projection system according to claim 10, wherein: The projection pattern comprises a linear pattern, The display pattern includes a linear auxiliary pattern extending on an extension line of the projection pattern.

12. The projection system according to claim 10, wherein: The display pattern includes an auxiliary pattern surrounding the projection pattern.

13. The projection system according to claim 10, wherein: The display pattern includes a detection pattern that overlaps with the detected projection pattern.

14. The projection system according to claim 7, wherein: The camera device can move relative to the projection surface. 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.

15. The projection system according to claim 14, wherein: The projection system includes a movable body capable of moving relative to the projection surface. The imaging device is held by the moving object.

16. The projection system of claim 15, wherein: The reference pattern indicates at least one of a planned movement path of the movable body and a planned position of a work to be performed by the movable body.

17. The projection system according to claim 10, wherein: 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, When the control device determines that there is an abnormality in the positional relationship, the control device reports the abnormality.

18. The projection system of claim 1, wherein: The full width at half maximum of the spectral transmittance of the optical filter is less than 15 nm.

19. The projection system of claim 1, wherein: The maximum spectral transmittance of the optical filter in the visible light band is greater than 50%.

20. The projection system of claim 1, wherein: The average transmittance of the optical filter in a visible light band other than a 30 nm band centered around the peak wavelength of the illumination light is 1% or less.

21. The projection system of claim 1, wherein: The maximum value of the illumination of the projection pattern projected onto the projection surface is greater than or equal to 1 lx.

22. The projection system of claim 1, wherein: The maximum value of the illumination of the projection pattern projected onto the projection surface, that is, the illumination LX (lx), Illuminance LY(lx) caused by ambient light at the position on the projection surface where the illuminance LX is obtained, an average transmittance TX (%) of the optical filter in the wavelength band of the illumination light, and The average transmittance TY (%) of the optical filter in the visible light band other than the 30 nm band centered on the peak wavelength of the illumination light satisfies the following relationship, 0.001≤(LX·TX) / (LY·TY).

23. The projection system according to any one of claims 1 to 22, 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.

24. An observation assisting device for assisting observation of a projection pattern projected onto a projection surface using illumination light emitted from an illumination device, wherein: The observation support device includes an optical filter having an average transmittance in the wavelength band of the illumination light higher than an average transmittance in a visible light band other than the wavelength band of the illumination light. The wavelength band of the illumination light is a wavelength band that is greater than or equal to a wavelength that is 5 nm lower than a peak wavelength of the illumination light and less than or equal to a wavelength that is 5 nm higher than the peak wavelength. The peak wavelength of the illumination light is a wavelength at which the maximum radiant flux of the illumination light can be obtained.

25. The observation aid according to claim 24, wherein: The observation assisting device includes a wearable device that can be worn by an observer of the projection pattern. The wearable device includes the optical filter, In a state where the observer wears the wearing tool, the optical filter faces the eyes of the observer.

26. The observation aid according to claim 24, wherein: The observation support device includes an imaging device including the optical filter.

27. An observation assisting device for assisting observation of a pattern displayed on a surface, wherein: The observation auxiliary device comprises: A display device that displays an image obtained by photographing the surface; and a control device electrically connected to the display device, The control device detects the pattern in the image displayed on the display device and generates a display pattern associated with the detected pattern. The display device displays the display pattern in an overlapping manner with the image.

28. The observation aid according to claim 27, wherein: The observation support device includes a lighting device that projects the pattern onto the surface.

Images