JP7268619B2 - projection device - Google Patents

Description

The present invention relates to a projection device for projecting a fringe pattern image onto an object to be measured in order to measure a three-dimensional shape.

A device using a phase shift method is known as a three-dimensional measuring device for measuring the three-dimensional shape of an object to be measured. The phase shift method is a technique for performing triangulation by projecting a plurality of phase-shifted fringe pattern images, and requires a projection device.

Patent Document 1 discloses a projection device capable of shifting the phase of a striped grid pattern at high speed. If the phase can be shifted at high speed, the accuracy of measuring the three-dimensional shape of the moving body is improved. The projection device disclosed in Patent Literature 1 includes a plurality of light sources and a fringe pattern forming screen paired with the light sources. Furthermore, the projection device disclosed in Patent Document 1 includes a half mirror that changes the direction of the light forming the stripe pattern in order to project the stripe patterns created by a plurality of screens from the same projection lens. there is

JP 2014-202492 A

The device disclosed in Patent Document 1 has a screen for each light source, and the distance between the screen and the half mirror is long, so the size of the device increases.

The present disclosure has been made based on this situation, and an object of the present disclosure is to provide a three-dimensional measuring apparatus that can be miniaturized.

The above objects are achieved by the combination of features stated in the independent claims, and the sub-claims define further advantageous embodiments. The symbols in parentheses described in the claims indicate the corresponding relationship with specific means described in the embodiments described later as one aspect, and do not limit the disclosed technical scope.

One disclosure for achieving the above objectives is
A projection device (20) for projecting a fringe pattern image onto a measurement object in order to measure the three-dimensional shape of the measurement object by a phase shift method,
at least three light sources (L);
a projection lens (21) for projecting a fringe pattern image;
A plurality of grating elements (23, 123, 223) having at least one face serving as grating planes (27, 28) on which mirrors (25) or half mirrors (26) are formed in a grid pattern. ,
a plurality of grating elements are arranged in the optical path between the light source and the projection lens, and arranged on both sides at positions where the light emitted by the light source is irradiated directly or through another grating element;
The half mirrors or mirrors are formed in a grid pattern so that the light emitted by the light source forms fringe patterns with different phases when passing through the projection lens.

The projection device comprises a plurality of grid elements. At least one surface of each of these lattice elements is a lattice surface. A half mirror or mirror is formed.

When the light emitted from the light source (hereinafter referred to as light source light) is incident on the lattice elements having such a configuration, the light output from the lattice elements forms a fringe pattern. Moreover, although the grating element is in the form of a grating, it is provided with at least one of a mirror and a half-mirror. Thus, the grating element can also change the path of the source light towards the projection lens.

Therefore, compared to a configuration separately provided with a screen for generating the lattice fringes and a mirror or a half mirror for directing the lattice fringes generated by the screen toward the projection lens, the light source and the mirror or the half mirror You can shorten the distance. Since this distance can be shortened, the size of the projector can be reduced.

The at least three light sources may be light sources emitting different colors from each other and may be configured to emit light simultaneously.

This projection device can be used in a three-dimensional shape measurement system that measures a three-dimensional shape by the color phase shift method.

The projection device includes three light sources that emit red, green, and blue light as light sources,
Equipped with two lattice elements,
The light emitted by the green emitting light source can be arranged to reach the projection lens via two grating elements.

In a camera, pixels of an image sensor are usually arranged in a Bayer pattern. The Bayer array has twice as many green pixels as there are red and blue pixels. Therefore, cameras are usually sensitive to green. As mentioned above, if green light reaches the projection lens via two grating elements, either red or blue light will reach the projection lens via only one grating element. Therefore, it is possible to suppress deterioration in the detection performance of red or blue, which has relatively low sensitivity in the camera.

The projection device may be configured such that the at least three light sources emit the same color as each other and have different emission periods.

This projection device can be used in a three-dimensional shape measurement system that measures a three-dimensional shape by a monochromatic phase shift method.

The projection device has four light sources,
comprising three grating elements (223),
Two of the four light sources emit light parallel to each other in a first direction and the remaining two of the four light sources emit light parallel to each other in a second direction orthogonal to the first direction. irradiate,
the first grating element receives light in the first direction on one surface and light in the second direction on the other surface;
In the second grating element, the light output in the first direction by the first grating element is incident on one surface, and the light in the second direction is incident on the other surface of the first grating element. Light different from light enters,
In the third grating element, the light output in the second direction by the second grating element is incident on one surface, and the light in the first direction is incident on the other surface of the first grating element. A configuration in which light different from the light is incident can be employed.

With this arrangement, the first grid element and the second grid element are aligned in a first direction, while the third grid element is aligned in a second direction with respect to the second grid element. Lined up. Therefore, since the three grid elements are arranged orthogonally, compared with the case where the three grid elements are arranged on a straight line, it is possible to suppress the length of the projection apparatus due to the arrangement of the grid elements. .

The projection device has four light sources,
comprising three grating elements (223),
Two of the four light sources emit light parallel to each other in a first direction and the remaining two of the four light sources emit light parallel to each other in a second direction orthogonal to the first direction. irradiate,
one surface of the first grating element receives light in a first direction and the other surface receives light in a second direction;
The second grating element has one surface on which light in the first direction and different from the light incident on the first grating element is incident, and the other surface is the light in the second direction. light different from the light incident on the first grating element through the
The third grating element is arranged at a position where the light output by the first grating element and the light outputted by the second grating element intersect, and the light output by the first grating element in the first direction is A configuration can be employed in which light is incident on one surface and light output in the second direction by the second grating element is incident on the other surface.

According to this configuration, the third grating element is arranged at a position where the light output from the first grating element and the light output from the second grating element intersect. Therefore, since the three grid elements are arranged orthogonally, the size of the projection apparatus in the grid element arrangement direction can be reduced.

Also, in this configuration, no light from any light source passes through three grating elements. Therefore, it is possible to reduce the extent to which the light from the light source is attenuated when passing through the grating element.

The projection device has four light sources,
comprising two grating elements (223),
Equipped with one half mirror element (226),
Two of the four light sources emit light parallel to each other in a first direction and the remaining two of the four light sources emit light parallel to each other in a second direction orthogonal to the first direction. irradiate,
one surface of the first grating element receives light in a first direction and the other surface receives light in a second direction;
The second grating element has one surface on which light in the first direction and different from the light incident on the first grating element is incident, and the other surface on which light in the second direction is incident. and light different from the light incident on the first grating element is incident,
The half-mirror element is arranged at a position where the light output from the first grating element and the light output from the second grating element intersect, and the first grating element outputs to one surface in the first direction. A configuration can be employed in which light is incident and light output in the second direction by the second grating element is incident on the other surface.
According to this configuration, the half mirror is arranged at a position where the light output from the first grating element and the light output from the second grating element intersect. Therefore, since the half mirror and the two grating elements are arranged orthogonally, it is possible to prevent one direction of the projection apparatus from becoming longer.

Moreover, in this configuration, light from any light source only needs to pass through two lattice elements and half mirrors. Therefore, it is possible to reduce the extent to which the light from the light source is attenuated when passing through the grating element and the half mirror.

The figure which shows the structure of the three-dimensional shape measurement system 1. FIG. 4 is an internal configuration diagram for projecting a composite fringe pattern image in the projector 20. FIG. FIG. 3 is a diagram showing in detail the configuration of lattice elements 23a and 23b; The figure explaining how green light source light progresses. The figure explaining how blue light source light progresses. FIG. 4 is a diagram for explaining how red light from a light source travels; 4 is a diagram for explaining colors output in each section C in the first embodiment; FIG. FIG. 4 is a diagram showing changes in each color with respect to phase in the first embodiment; The figure which shows the process which measures a three-dimensional shape. The block diagram of a comparative example. FIG. 4 is a diagram showing the configuration of lattice elements 23a and 123 in the second embodiment; FIG. 11 is a diagram for explaining colors output in each section C in the second embodiment; The figure which shows five patterns when it is set as the four light sources L. FIG. FIG. 10 is a diagram showing the configuration of a lattice element 223 in pattern PT1-1; FIG. 10 is a diagram showing transmission and reflection of light at grating elements 223a in pattern PT1-1; FIG. 10 is a diagram showing transmission and reflection of light at grating element 223b in pattern PT1-1; FIG. 10 is a diagram showing transmission and reflection of light at grating element 223c in pattern PT1-1; FIG. 10 is a diagram for explaining colors output in each section C in the pattern PT1-1; FIG. 10 is a diagram showing the configuration of the lattice element 223 in the pattern PT1-2; FIG. 10 is a diagram for explaining colors output in each section C in patterns PT1-2; FIG. 10 is a diagram showing the configuration of a lattice element 223 in pattern PT2-1; FIG. 10 is a diagram for explaining colors output in each section C in pattern PT2-1; FIG. 10 is a diagram showing the configuration of a lattice element 223 in pattern PT2-2; FIG. 10 is a diagram for explaining colors output in each section C in pattern PT2-2; FIG. 10 is a diagram showing the configuration of a lattice element 223 in pattern PT3-1; FIG. 10 is a diagram for explaining colors output in each section C in pattern PT3-1; FIG. 10 is a diagram showing the configuration of a lattice element 223 in pattern PT3-2; FIG. 10 is a diagram for explaining colors output in each section C in pattern PT3-2; FIG. 4 is a diagram showing the configuration of a lattice element 223 in pattern PT4-1; FIG. 10 is a diagram for explaining colors output in each section C in pattern PT4-1; FIG. 10 is a diagram showing the configuration of a lattice element 223 in pattern PT4-2; FIG. 10 is a diagram for explaining colors output in each section C in pattern PT4-2; FIG. 10 is a diagram showing the configuration of a lattice element 223 in pattern PT5-1; FIG. 10 is a diagram for explaining colors output in each section C in pattern PT5-1; FIG. 10 is a diagram showing the configuration of a lattice element 223 in pattern PT5-2; FIG. 10 is a diagram for explaining colors output in each section C in pattern PT5-2;

<First embodiment>
Hereinafter, embodiments will be described based on the drawings. FIG. 1 is a diagram showing the configuration of a three-dimensional shape measurement system 1. As shown in FIG. The three-dimensional shape measurement system 1 includes a control device 10 , a projector 20 that is a projection device, and a camera 30 . A three-dimensional shape measurement system 1 measures the three-dimensional shape of a measurement object 5 placed on a workbench 2 using a phase shift method.

The upper surface of the workbench 2 is flat, and the object 5 to be measured is positioned at an arbitrary position on the workbench 2 . The three-dimensional shape measurement system 1 is used, for example, as the eyes of a robot when the robot is caused to perform picking, assembly work, product inspection, and the like.

The controller 10 can be equipped with a computer. Control device 10 generates image data, which is data of an image projected by projector 20 , and outputs the image data to projector 20 . The image projected by the projector 20 is a striped pattern image.

Further, the control device 10 acquires image data representing an image captured by the camera 30 while the stripe pattern image is projected from the projector 20 onto the measurement object 5 . Then, based on the image data, the three-dimensional shape of the measurement object 5 is measured by the phase shift method.

The stripe pattern image projected onto the measurement object 5 by the projector 20 in order to measure the three-dimensional shape is a composite stripe pattern image. The composite striped pattern image is a striped pattern image obtained by synthesizing monochromatic striped pattern images of three colors, red, green, and blue, each of which has a periodic change in brightness.

A monochromatic striped pattern image is an image in which the luminance of any one of red, green, and blue varies sinusoidally in one direction of the image, and the luminance is constant in the direction perpendicular to the one direction. Also, in the composite striped pattern image, the phases of the three monochromatic striped pattern images are shifted by a predetermined angle.

As an example, the phase of the red monochromatic stripe pattern image is the most advanced, and the phase of the green monochromatic stripe pattern image is delayed by 2π/3. The single-color fringe pattern image of blue is delayed in phase from the single-color fringe pattern image of green by 2π/3.

The projector 20 projects the composite fringe pattern image described above. The internal configuration for projecting the composite fringe pattern image in the projector 20 will be described later with reference to FIG. The camera 30 is a camera capable of capturing color images. The camera 30 is a digital camera, and has a large number of light detection elements such as photodiodes on its light receiving surface in the vertical and horizontal directions. Each photodetector corresponds to one pixel. It is assumed that the x direction of the image projected by the projector 20 and the x direction of the image captured by the camera 30 are matched.

An RGB color filter is provided in the light arrival direction of the photodetector. The RGB color filter is formed by arranging any one of red, green, and blue color filters in the light arrival direction of each photodetector. The arrangement of red, green, and blue color filters generally follows the Bayer arrangement. The distance between projector 20 and camera 30 is measured in advance.

[Internal Configuration of Projector 20]
An internal configuration for projecting a composite fringe pattern image in the projector 20 will be described with reference to FIG. The projector 20 has three light sources L. As shown in FIG. Both light sources L may be LEDs, for example. The light source L(R) emits red light. The light source L(B) emits blue light. The light source L(G) emits green light.

In FIG. 2, the dashed-dotted line indicates the optical path. Both optical paths pass through projection lens 21 . The projection lens 21 is a lens that projects the fringe pattern image shown in FIG. A condensing lens 22 is disposed closer to the projection lens 21 than each light source L in the optical path. The condenser lens 22 collects light emitted by the light source L (hereinafter referred to as light source light).

A grating element 23 is arranged on the projection lens 21 side of the optical path from the condenser lens 22 . Two grating elements 23 a and 23 b are arranged in the projector 20 . The two grating elements 23a and 23b are referred to as grating element 23 when they are not distinguished from each other. The two grating elements 23 a and 23 b are arranged on the optical axis of the projection lens 21 and closer to the green light source L(G) than the projection lens 21 .

One grating element 23a receives blue light source light on one surface and green light source light on the other surface. The other grating element 23b has one surface on which red light source light is incident, and an opposite surface on which blue light source light and green light source light are incident.

FIG. 3 shows in detail the structure of the lattice elements 23a and 23b. The grating element 23a uses a transparent glass 24 as a base material. The shape of the glass 24 is determined by the shape of the fringe pattern image that needs to be produced. The shape of the glass 24 is, for example, a rectangular plate shape. A mirror 25 is vapor-deposited on one surface of the glass 24 in a grid pattern. A half mirror 26 is deposited on the other surface of the glass 24 . The surface of the glass 24 on which the mirrors 25 are vapor-deposited in a lattice pattern is a lattice mirror surface 27 , and the surface on which the half mirrors 26 are vapor-deposited in a lattice pattern is a lattice half-mirror surface 28 . These grating mirror surface 27 and grating half mirror surface 28 are grating surfaces.

The portions where the mirrors 25 are formed on the grating mirror surface 27 of the grating element 23a are the first section C1 and the second section C2. Section C will now be described. Section C is divided into 6 sections from 1st to 6th in this embodiment. Sections C are periodically repeated in one direction of the glass 24 from the first section C1 to the sixth section C6, with six sections as one period. The size of each section C is the same as each other.

One cycle corresponds to one cycle of the stripe pattern image, and the direction in which the segment C repeats corresponds to the direction in which the stripe pattern repeats. Also, the grating means thin parallel lines as in the case of a diffraction grating or the like, and the direction in which the segments C repeat is the direction orthogonal to the grating. Therefore, the direction in which each section C extends is the same as the direction in which the grid extends.

The grating mirror surface 27 has mirrors 25 deposited on the first section C1 and the second section C2. On the grating half mirror surface 28, the half mirror 26 is vapour-deposited on the third section C3.

The grating element 23b is also made of transparent glass 24 as a base material. The grating element 23b also has a grating mirror surface 27 on which a mirror 25 is vapor-deposited in a lattice pattern on one side, and a grating half-mirror surface 28 on which a half mirror 26 is vapor-deposited on the other side.

A mirror 25 is vapor-deposited on the sixth section C6 of the grating mirror surface 27 of the grating element 23b. Half mirrors 26 are deposited on the first section C1 and the fifth section C5 on the grating half mirror surface 28 of the grating element 23b.

When the mirror 25 and the half mirror 26 are deposited on the two grating elements 23a and 23b in this way, the projection lens 21 projects a fringe pattern image. The reason for this will be explained in detail below. FIG. 4 is a diagram explaining how the green light source light travels. The green light source light is incident on the grating half mirror surface 28 of the grating element 23a at an incident angle of 45 degrees. Since the mirrors 25 are formed in the first section C1 and the second section C2 of the grating element 23a, the green light source light does not pass through the first section C1 and the second section C2. A half mirror 26 is formed in the third segment C3, but since it is a half mirror 26, part of the light passes through the grating element 23a. Since the fourth section C4 to the sixth section C6 of the grating element 23a are made of glass 24, the green light source light passes through the fourth section C4 to the sixth section C6 of the grating element 23a.

Since the third section C3 and the fourth section C4 of the grating element 23b are the glass 24 and the fifth section C5 is the half mirror 26, green light source light is emitted from the third section C3 to the fifth section C5 of the grating element 23b. passes through. Since the sixth section C6 of the grating element 23b is a mirror 25, it does not transmit the green light source. As described above, the green light source light is output from the third section C3, the fourth section C4, and the fifth section C5 of the grating element 23b.

FIG. 5 is a diagram illustrating how blue light from a light source travels. The blue light source light is incident on the grating mirror surface 27 of the grating element 23a at an incident angle of 45 degrees. Since the mirrors 25 are formed on the first section C1 and the second section C2 of the grating element 23a, the blue light source light is reflected by the first section C1 and the second section C2 toward the grating element 23b. . Since the half mirror 26 is formed in the third section C3, part of the light is reflected toward the grating element 23b. Since the fourth section C4 to the sixth section C6 of the grating element 23a are made of glass 24, the blue light source light is transmitted through the fourth section C4 to the sixth section C6 of the grating element 23a and directed to the grating element 23b. do not have.

A first section C1 of the grating element 23b is a half mirror 26, and a second section C2 and a third section C3 are glasses 24. FIG. Therefore, the blue light source light incident on the first section C1 to the third section C3 of the grating half mirror surface 28 of the grating element 23b is transmitted through the grating element 23b. Output from the first section C1, the second section C2, and the third section C3.

FIG. 6 is a diagram illustrating how red light from the light source travels. The red light source light is incident on the grating mirror surface 27 of the grating element 23b at an incident angle of 45 degrees. Since the half mirrors 26 are formed in the first section C1 and the fifth section C5 of the grating element 23b, the red light source light is reflected by the first section C1 and the fifth section C5 and directed toward the projection lens 21. Head. Since the second section C2 to the fourth section C4 of the grating element 23b are made of glass 24, the red light source light is transmitted through the second section C2 to the fourth section C4 of the grating element 23b, and is directed toward the projection lens 21. do not have. Since the sixth section C6 of the grating element 23b is the mirror 25, the red light source light is also reflected by the sixth section C6 toward the projection lens 21. FIG.

The above is summarized as shown in FIG. In FIG. 7, each colored circle means that light is output. Also, as shown in FIG. 7, each section C can be considered to correspond to a phase of 60 degrees. As can be seen from FIG. 7, each color switches between light output and non-output every 180 degrees. That is, for each color, light output and non-output are switched in a sinusoidal manner. Also, the phase of each color is shifted by 120 degrees. It can thus be seen that a composite fringe pattern image is produced which can be used in the color phase shift method.

FIG. 8 shows the change of each color in the direction in which the phase periodically changes. The synthesized fringe pattern image is an image obtained by synthesizing the colors output at each position corresponding to the phase in FIG.

[Processing for measuring three-dimensional shape]
Next, processing for measuring a three-dimensional shape will be described. FIG. 9 shows processing for measuring a three-dimensional shape. The processing shown in FIG. 9 is executed by the control device 10 based on the user's operation. In step (hereinafter, step is omitted) S11, the composite stripe pattern image is projected onto the measurement object 5, and the image of the measurement object 5 at that time is photographed by the camera 30. FIG. A composite fringe pattern image is generated by causing each light source L to emit light at the same time.

In S12, the luminance value (hereinafter referred to as photographed luminance value) _Ib of the photographed image for each of the three colors of red, green, and blue is obtained. This means obtaining data indicating the shooting luminance value _Ib for each color pixel. A color pixel means a pixel that detects red light, a pixel that detects green light, or a pixel that detects blue light, or a generic term for them.

In S13, the shooting luminance value _Ib of each color is normalized. Normalization is a process of aligning the maximum luminance and minimum luminance of each color. In S14, the phase θ(x, y) at each pixel coordinate (x, y) is calculated from Equation 1 based on the normalized shooting luminance value _Ib for each color pixel at each pixel coordinate (x, y). calculate.

なお、式１において、Ｎは位相シフト総回数、ｎは色別に取得した撮影画像の位相シフト回数である。縞パターン画像において最も早い位相とした色のｎが０、次に位相が早い色のｎが１、最も位相が遅い色のｎが２である。位相シフト総回数Ｎは３である。また、ａ（ｘ、ｙ）は輝度振幅、ｂ（ｘ、ｙ）は背景輝度、θ（ｘ、ｙ）はｎ＝０での位相θである。

In Expression 1, N is the total number of phase shifts, and n is the number of phase shifts of the captured image acquired for each color. In the fringe pattern image, n is 0 for the color with the earliest phase, n is 1 for the color with the second earliest phase, and n is 2 for the color with the slowest phase. The total number of phase shifts N is three. Also, a(x, y) is the luminance amplitude, b(x, y) is the background luminance, and θ(x, y) is the phase θ at n=0.

In Equation 1, there are three unknowns, a(x, y), b(x, y), and θ(x, y). Therefore, if the photographing luminance value _Ib of each coordinate (x, y) for each color normalized in S13 is used, three unknowns including the phase θ, a (x, y), b (x, y), θ(x, y) can be calculated for each pixel coordinate.

In S15, the height coordinate _zm of the coordinate measurement point P is determined from the phase θ(x, y) of each pixel coordinate (x, y) calculated in S14. A coordinate measurement point P is a point on the surface of the object 5 to be measured or the workbench 2 . The height coordinate _zm is the distance from the plane containing the projector 20 and the camera 30 to the object. The height coordinate _zm is determined using a graph showing the relationship between the phase θ and the height coordinate _zm and the phase θ calculated in S14. In S15, the height coordinate _zm of each coordinate measurement point P is determined by applying the phase θ(x, y) calculated in S14 to the previously obtained graph.

In S16, the horizontal coordinates ( _xm , _ym ) are determined for the coordinate measurement point P whose height coordinate _zm was determined in S15. The height coordinate _zm determined in S15 is associated with the pixel coordinates (x, y). Once the pixel coordinates (x, y) are determined, the directions (δ _x , δ _y ) with respect to the camera 30 are determined. Note that _δx is the angle between the direction from the camera 30 toward the coordinate measurement point P and the _zm axis on _{the xmzm} plane. _δy is the angle between the direction from the camera 30 to the coordinate measurement point P and the _zm axis on _{the ymzm} plane. The horizontal coordinates (x _m , y _m ) can be calculated from the height coordinates z _m and δ _m , δ _y by geometric calculation.

The three-dimensional shape of the measurement object 5 can be measured by executing the processing from S14 to S16 for each pixel coordinate (x, y).

[Summary of the first embodiment]
In the first embodiment described above, the projector 20 is provided with two grating elements 23a and 23b. These grating elements 23a and 23b have mirrors 25 formed in a grating pattern on one side and mirrors 25 on the other side. A half-mirror 26 is formed in a grid pattern at the end. When the light source light is incident on the lattice elements 23a and 23b having such a configuration, the light output from the lattice elements 23a and 23b forms a fringe pattern. Moreover, the grating elements 23a and 23b are provided with mirrors 25 and half mirrors 26 although they are in the form of gratings. Therefore, the grating elements 23 a and 23 b can also change the course of the light from the light source to the direction of the projection lens 21 .

The configuration of this embodiment is compared with the configuration of the comparative example shown in FIG. The configuration of the comparative example shown in FIG. 10 is a configuration in which a screen for generating lattice fringes and a half mirror for directing the lattice fringes generated by the screen toward the projection lens 21 are provided separately. Compared to the configuration of this comparative example, the configuration of the present embodiment can shorten the distance between the light source L(G) and the grating element 23a and the distance between the light source L(B) and the grating element 23a. Since this distance can be shortened, the size of the projector 20 can be reduced.

Also, in the projector 20 of this embodiment, the green light source light reaches the projection lens 21 via the two grating elements 23a and 23b. The red light source light reaches the projection lens 21 via only one grating element 23b.

Due to this configuration, the green light source light may be less bright than the red light source light. However, since the camera 30 normally has pixels arranged in a Bayer array, green sensitivity is relatively good. Therefore, there are many cases where the green sensitivity is lowered and the three-dimensional measurement is not hindered. In the present embodiment, it is possible to suppress deterioration in detection performance for red, which has relatively low sensitivity, so that it is possible to suppress failure of three-dimensional measurement due to insufficient light intensity.

<Second embodiment>
Next, a second embodiment will be described. In the following description of the second embodiment, the elements having the same reference numerals as those used so far are the same as the elements having the same reference numerals in the previous embodiments unless otherwise specified. Moreover, when only part of the configuration is described, the previously described embodiments can be applied to the other portions of the configuration.

FIG. 11 shows the grid element 23a and grid element 123 included in the projector 20 in the second embodiment. In the second embodiment, a lattice element 123 is provided instead of the lattice element 23b. Green and blue light source lights enter the same grating element 23a as in the first embodiment. Further, in the second embodiment, the projection lens 21 is arranged in the optical path after the red light source light has passed through the grating element 123 .

The grating element 123 differs from the grating element 23b of the first embodiment in that the mirrors 25 are deposited on the second section C2, the third section C3 and the fourth section C4 of the grating mirror surface 27. FIG. The grating half mirror surface 28 of the grating element 123 has the half mirrors 26 deposited on the first section C1 and the fifth section C5, like the grating element 23b of the first embodiment.

In the second embodiment having such a configuration, the fringe pattern image projected from the projection lens 21 has the relationship between each section C and the color as shown in FIG. As can be seen from FIG. 12, in the configuration of the second embodiment as well, each color is sinusoidally switched between light output and non-output, and the phase of each color is shifted by 120 degrees.

<Third Embodiment>
In the third embodiment, four light sources L are used. The colors of the four light sources L are different from each other. As an example, green, blue, red, and infrared are used in the following description. One or all of these colors can be other colors such as ultraviolet light.

In the third embodiment, five types of light source arrangements using four light sources L and configurations of the lattice elements 223 will be described. FIG. 13 shows the arrangement of the light sources and the arrangement of the lattice elements 223 in the five types of patterns PT. 13 and subsequent drawings, green light is denoted by G, blue light by B, red light by R, and infrared light by IR.

When four light sources L are used, three grating elements 223 or two grating elements 223 and a half mirror element 226 are required. When three grating elements 223 are provided, two light source lights are projected via the three grating elements 223 as shown in patterns PT1 to PT4. In the pattern PT5, the number of grating elements 223 that pass through all four light sources is one.

The pattern PT1 and the pattern PT2 are patterns in which the optical axis of light transmitted through the first grating element 223 passes through the second grating element 223 . On the other hand, the pattern PT3 and the pattern PT4 are patterns in which the optical axis of light transmitted through the first grating element 223 is reflected by the second grating element 223 .

The differences between the pattern PT1 and the pattern PT2 are as follows. In the pattern PT1, the light source light passing through the first and second grating elements 223 also passes through the third grating element 223. FIG. On the other hand, in the pattern PT2, the light source light that has passed through the first and second grating elements 223 is reflected by the third grating element 223. FIG.

The difference between the patterns PT3 and PT4 is the same as the difference between the patterns PT1 and PT2. In the pattern PT3, the light source light passing through the first and second grating elements 223 passes through the third grating element 223. FIG. On the other hand, in the pattern PT4, the light source light that has passed through the first and second grating elements 223 is reflected by the third grating element 223. FIG. Each pattern PT has two types of specific configurations of the lattice elements 223 that realize each pattern PT. A specific configuration of the lattice element 223 that implements each pattern PT will be described below.

[Pattern PT1-1]
FIG. 14 shows the configuration of the lattice element 223 in the pattern PT1-1. A pattern PT1-1 is a first specific configuration of the lattice element 223 that implements the pattern PT1. In the pattern PT1-1, three types of lattice elements 223a, 223b, and 223c are arranged in the same posture on a straight line in the traveling direction of the green light source light. The same side of each of the three grating elements 223a, 223b, and 223c is the grating half mirror surface . On the side opposite to the grating half mirror surface 28, the grating element 223a and the grating element 223b form the grating mirror surface 27. As shown in FIG. On the other hand, neither the mirror 25 nor the half mirror 26 is deposited on the rear surface of the grating half mirror surface 28 in the grating element 223c.

In the third embodiment, there are four partitions C. The direction in which segment C repeats is the same as in the first embodiment. In the grating element 223a, the first section C1 is glass 24, and the second section C2 is vapor-deposited with a half mirror 26. As shown in FIG. A mirror 25 is deposited on the third section C3. The fourth section C4 is optional. That is, the fourth section C4 may be any one of the glass 24, the mirror 25, and the half mirror .

In the grating element 223b, the first section C1 and the second section C2 are glass 24, the third section C3 is the half mirror 26, and the fourth section C4 is the mirror 25. FIG. In the grating element 223c, the first section C1 and the fourth section C4 are the half mirrors 26, and the second section C2 and the third section C3 are the glass 24. FIG.

The transmission and reflection of light in the configuration of FIG. 14 will be described with reference to FIGS. 15 to 17. FIG. FIG. 15 shows the transmission and reflection of light at grating element 223a. Green light source light enters the grating half mirror surface 28 of the grating element 223a, and blue light source light enters the grating mirror surface 27 of the grating element 223a.

Due to the configuration of each section C of the grating element 223a, in the direction of the grating element 223b, the first section C1 emits green light and the second section C2 emits green light and blue light. In the third section C3, blue light is emitted in the direction of the grating element 223b. The fourth segment C4 is optional, so green and blue light may or may not be directed towards grating element 223b.

FIG. 16 shows the transmission and reflection of light at grating element 223b. In the grating element 223b, green light is incident on the first segment C1 of the grating half mirror surface 28, green light and blue light are incident on the second segment C2, and blue light is incident on the third segment C3. Red light is incident on the grating mirror surface 27 of the grating element 223b.

Due to the configuration of each section C of the grating element 223b, in the direction of the grating element 223c, the first section C1 emits green light and the second section C2 emits green light and blue light. In the third section C3, blue light and red light are emitted in the direction of the grating element 223c. Since the fourth section C4 of the grating element 223b is the mirror 25, even if the light enters the grating half mirror surface 28, it does not travel in the direction of the grating element 223c. Therefore, in the fourth section C4 of the grating element 223c, red light is emitted in the direction of the grating element 223c.

FIG. 17 shows the transmission and reflection of light at grating element 223c. In the grating element 223c, green light is incident on the first segment C1 of the grating half mirror surface 28, green light and blue light are incident on the second segment C2, and blue light and red light are incident on the third segment C3. Then, red light is incident on the fourth segment C4. Infrared light is incident on the grating mirror surface 27 of the grating element 223c.

FIG. 18 shows the color of each section C output from grid element 223c. The first section C1 outputs green light and infrared light. The second section C2 outputs green light and blue light. The third section C3 outputs blue light and red light. The fourth section C4 outputs red light and infrared light.

As can be seen from FIG. 18, for each color, light output and non-output are switched every 180 degrees. That is, for each color, light output and non-output are switched in a sinusoidal manner. Also, the phase of each color is shifted by 90 degrees. It can thus be seen that a composite fringe pattern image is produced which can be used in the color phase shift method.

[Pattern PT1-2]
Next, the pattern PT1-2 will be explained. A pattern PT1-2 is a second specific configuration of the lattice element 223 that implements the pattern PT1. FIG. 19 shows the configuration of the lattice element 223 in the pattern PT1-2. Also in the pattern PT1-2, the three types of grating elements 223a, 223b, and 223c are arranged in the same posture on a straight line in the traveling direction of the green light source light. The grating element 223a has a grating mirror surface 27 on which the blue light is irradiated. The half-mirror 26 is not vapor-deposited on the surface that was the grating half-mirror surface 28 in the pattern PT1-1.

The grid element 223b and the grid element 223c in the pattern PT1-2 have a grid half-mirror surface 28 on the green light source L side, and the mirror 25 is not vapor-deposited on the opposite side.

In pattern PT1-2, grating element 223a has glass 24 in first section C1 and second section C2, and mirror 25 in third section C3 and fourth section C4. The grating element 223b has glass 24 in the first section C1 and the fourth section C4, and half mirrors 26 in the second section C2 and the third section C3. The grating element 223c has glass 24 in the second section C2 and the third section C3, and half mirrors 26 in the first section C1 and the fourth section C4.

FIG. 20 shows the color of each section C output from grid element 223c in the configuration shown in FIG. The first section C1 outputs green light and infrared light. The second section C2 outputs green light and red light. The third section C3 outputs blue light and red light. The fourth section C4 outputs blue light and infrared light.

As can be seen from FIG. 20, the patterns PT1-2 also switch between light output and non-output for each color every 180 degrees. Also, the phase of each color is shifted by 90 degrees. Therefore, it can be seen that the pattern PT1-2 also produces a composite fringe pattern image that can be used in the color phase shift method.

[Pattern PT2-1]
FIG. 21 shows the configuration of the lattice element 223 in the pattern PT2-1. Also in the pattern PT2-1, the three types of grating elements 223a, 223b, and 223c are arranged in the same posture on a straight line in the traveling direction of the green light source light. Also, the three grating elements 223a, 223b, and 223c have the grating mirror surface 27 and the grating half mirror surface 28 on the same side.

However, in pattern PT2-1, the final light is output downward in FIG. The first grating element 223a and the second grating element 223b in the pattern PT2-1 have the mirror 25 and the half mirror 26 in the same section C as the first grating element 223a and the second grating element 223b in the pattern PT1-1. vapor-deposited. The third grating element 223c in the pattern PT2-2 has the half mirrors 26 in the first section C1 and the fourth section C4, and the mirrors 25 in the second section C2 and the third section C3.

FIG. 22 shows the color of each section C output from the lattice element 223c in the pattern PT2-1. The third grating element 223c in the pattern PT2-1 is different from the third grating element 223c in the pattern PT1-1 only in that the second section C2 and the third section C3 are changed from the glass 24 to the mirror 25. . Therefore, in the pattern PT2-1, although the final light is output downward in FIG. 21, the same synthetic fringe pattern image as in the pattern PT1-1 is generated.

[Pattern PT2-2]
FIG. 23 shows the configuration of the lattice element 223 in the pattern PT2-2. Also in the pattern PT2-2, the three types of lattice elements 223a, 223b, and 223c are arranged in the same posture on a straight line in the traveling direction of the green light source light.

The first grating element 223a has glass 24 in the first section C1 and the second section C2, and mirrors 25 in the third section C3 and the fourth section C4. The second grating element 223b has the glass 24 in the first section C1 and the fourth section C4, and the half mirror 26 in the second section C2 and the third section C3. The third grating element 223c has half mirrors 26 in the first section C1 and the fourth section C4, and mirrors 25 in the second section C2 and the third section C3.

FIG. 24 shows the color of each section C output from the lattice element 223c in the pattern PT2-2. In the pattern PT2-2, the phases of the blue light and the red light are opposite to those in the pattern PT2-1, but in the pattern PT2-2 as well, the output and non-output of light are switched every 180 degrees for each color. . Also, the phase of each color is shifted by 90 degrees. Therefore, it can be seen that the pattern PT2-2 also produces a composite fringe pattern image that can be used in the color phase shift method.

[Pattern PT3-1]
FIG. 25 shows the configuration of the lattice element 223 in the pattern PT3-1. In the pattern PT3-1, the light source L that emits green light and the light source L that emits infrared light irradiate light parallel to each other in the horizontal direction in the figure, which is the first direction. The light source L that emits blue light and the light source L that emits red light irradiate light parallel to each other in the longitudinal direction of the drawing, which is the second direction orthogonal to the first direction.

Also, in the pattern PT3-1, the two lattice elements 223a and 223b are arranged in the same posture on a straight line in the traveling direction of the green light source light. The third grating element 223c through which the green light passes is arranged in the same posture as the grating element 223b on a straight line in the traveling direction of the red light. Light from the light source is incident on the grating mirror surface 27 and the grating half mirror surface 28 of each grating element 223a, 223b, 223c at an incident angle of 45 degrees.

In the grating element 223a, green light is incident on the grating half mirror surface 28 and blue light is incident on the grating mirror surface 27, similarly to the pattern PT thus far. Light output from the grating element 223a in the lateral direction of the figure, that is, green light and blue light, enters the grating half mirror surface 28 of the grating element 223b, and red light enters the grating mirror surface 27 of the grating element 223b. The light output in the longitudinal direction of the figure by the grating element 223b is incident on one surface of the grating element 223c, and the infrared light is incident on the grating half-mirror surface .

The first section C1 of the grating element 223a is the glass 24, the second section C2 is the half mirror 26, the third section C3 is the mirror 25 and the fourth section C4 is optional. The first section C1 and the second section C2 of the grating element 223b are the mirrors 25, the third section C3 is the half mirror 26, and the fourth section C4 is the glass 24. FIG.

The first section C1 of the grating element 223c is the half mirror 26, the second section C2 and the third section C3 are the glass 24, and the fourth section C4 is the half mirror 26. FIG. Note that the section C of the grating element 223c is a portion into which the light transmitted or reflected by each section C of the grating element 223a or the grating element 223b is incident.

FIG. 26 shows the color of each section C output from the lattice element 223c in the pattern PT3-1. In the pattern PT3-1, each color switches between light output and non-output in the same phase as the pattern PT2-1. Therefore, it can be seen that the pattern PT3-1 also produces a composite fringe pattern image that can be used in the color phase shift method.

Further, according to the structure of this pattern PT3-1, the first lattice element 223a and the second lattice element 223b are arranged in the horizontal direction of the drawing, whereas the third lattice element 223c is arranged in the lattice element 223b. are aligned vertically in the figure. Therefore, since the three grid elements 223 are arranged orthogonally, compared with the case where the three grid elements 223 are arranged on a straight line, the arrangement of the grid elements 223 makes the projector 20 longer. can be suppressed.

[Pattern PT3-2]
FIG. 27 shows the configuration of the lattice element 223 in the pattern PT3-2. The positions of the three types of lattice elements 223a, 223b, and 223c in pattern PT3-2 are the same as in pattern PT3-1. Therefore, even with the pattern PT3-2, it is possible to prevent the projector 20 from becoming longer due to the arrangement of the lattice elements 223 compared to the case where the three lattice elements 223 are arranged on a straight line.

The first grating element 223a has glass 24 in the first section C1 and the second section C2, and mirrors 25 in the third section C3 and the fourth section C4. The second grating element 223b has mirrors 25 in the first section C1 and the fourth section C4, and half mirrors 26 in the second section C2 and the third section C3. The third grating element 223c has half mirrors 26 in the first section C1 and the fourth section C4, and glass 24 in the second section C2 and the third section C3.

FIG. 28 shows the color of each section C output from the lattice element 223c in the pattern PT3-2. In the pattern PT3-2, the phases of blue light and red light are opposite to those in the pattern PT3-1, but the rest is the same as the pattern PT3-1. Therefore, it can be seen that the pattern PT3-2 also produces a composite fringe pattern image that can be used in the color phase shift method.

[Pattern PT4-1]
FIG. 29 shows the configuration of the lattice element 223 in the pattern PT4-1. The positions of the three types of lattice elements 223a, 223b, and 223c in pattern PT4-1 are the same as in patterns PT3-1 and 3-2. Therefore, the pattern PT4-1 can also prevent the projector 20 from becoming too long.

However, in the pattern PT4-1, the grating element 223c has the grating mirror surface 27 on the infrared light incident side and the grating half mirror surface 28 on the red light incident side. Also, the final light is output to the right in FIG.

In the first grating element 223a, the first section C1 is the glass 24, the second section C2 is the half mirror 26, the third section C3 is the mirror 25, and the fourth section C4 is optional. The second grating element 223b has the mirrors 25 in the first section C1 and the second section C2, the half mirror 26 in the third section C3, and the glass 24 in the fourth section C4. The third grating element 223c has half mirrors 26 in the first section C1 and the fourth section C4, and mirrors 25 in the second section C2 and the third section C3.

FIG. 30 shows the color of each section C output from the lattice element 223c in the pattern PT4-1. In the pattern PT4-1, each color has the same phase as the pattern PT3-1. Therefore, it can be seen that the pattern PT4-1 also produces a composite fringe pattern image that can be used in the color phase shift method.

[Pattern PT4-2]
FIG. 31 shows the configuration of the lattice element 223 in the pattern PT4-2. The positions of the three types of lattice elements 223a, 223b, and 223c in pattern PT4-2 are the same as in pattern PT3-1. As with the pattern PT4-1, the grating element 223c has the grating mirror surface 27 on the side on which the infrared light is incident.

The first grating element 223a has glass 24 in the first section C1 and the second section C2, and mirrors 25 in the third section C3 and the fourth section C4. The second grating element 223b has mirrors 25 in the first section C1 and the fourth section C4, and half mirrors 26 in the second section C2 and the third section C3. The third grating element 223c has half mirrors 26 in the first section C1 and the fourth section C4, and mirrors 25 in the second section C2 and the third section C3.

FIG. 32 shows the color of each section C output from the lattice element 223c in the pattern PT4-2. In pattern PT4-2, each color has the same phase as pattern PT3-2. Therefore, it can be seen that the pattern PT4-2 also produces a composite fringe pattern image that can be used in the color phase shift method.

[Pattern PT5-1]
FIG. 33 shows the configuration of the lattice element 223 in the pattern PT5-1. In the pattern PT5-1, unlike the patterns PT so far, the second lattice elements 223b are not arranged in the direction in which the green light source light travels straight. In the pattern PT5-1, the lattice element 223b is arranged at the position of the third lattice element 223c in the pattern PT4. Also, in the pattern PT5-1, the lattice element 223b is oriented 90 degrees different from the lattice elements 223b used so far. They are arranged so that they are closer to each other.

The third lattice element 223c is arranged at the position of the second lattice element 223b in the pattern PT4. The grid element 223c is arranged at an angle parallel to the grid element 223b in this pattern PT5-1. Light from the light source is incident on the grating mirror surface 27 and the grating half mirror surface 28 of each grating element 223a, 223b, 223c at an incident angle of 45 degrees.

Green light source light enters the grating half mirror surface 28 of the first grating element 223a, and blue light source light enters the grating mirror surface 27 of the first grating element 223a. Red light source light enters the grating half mirror surface 28 of the grating element 223b, and infrared light source light enters the grating mirror surface 27 of the grating element 223b. Incidentally, the infrared light is incident on 223b in parallel with the green light. Also, the red light is incident on the grating element 223b parallel to the blue light and traveling in the opposite direction. Red light and infrared light are incident on the lattice mirror surface 27 of the lattice element 223c, and green light and blue light are incident on the lattice half mirror surface 28 of the lattice element 223c.

In the grating element 223a, the first section C1 is the glass 24, the second section C2 is the half mirror 26, the third section C3 is the mirror 25, and the fourth section C4 is optional. The grating element 223b has the mirror 25 in the first section C1, the optional second section C2, the glass 24 in the third section C3, and the half mirror 26 in the fourth section C4. The grating element 223c has the half mirror 26 in the first section C1, the glass 24 in the second section C2, the half mirror 26 in the third section C3, and the mirror 25 in the fourth section C4.

FIG. 34 shows the color of each section C output from the lattice element 223c in the pattern PT5-1. In the pattern PT5-1, each color has the same phase as the pattern PT3-1. Therefore, it can be seen that the pattern PT5-1 also produces a composite fringe pattern image that can be used in the color phase shift method.

In the pattern PT5-1, the green light source L and the blue light source L of the four light sources L irradiate the grating mirror surface 27 and the grating half mirror surface 28 of the same grating element 223a, respectively. The remaining two light sources L, that is, the infrared light source L and the red light source L illuminate the grating mirror surface 27 and the grating half mirror surface 28 of another grating element 223b, respectively.

A lattice element 223c is arranged at a position where the light output from the lattice element 223a and the light output from the lattice element 223b intersect. With such an arrangement of the three grating elements 223 a , 223 b , 223 c , any light source light passes through only two grating elements 223 , and no light source light passes through the three grating elements 223 . Therefore, the degree of attenuation of the light source light passing through the grating element 223 can be reduced.

[Pattern PT5-2]
FIG. 35 shows the configuration of the lattice element 223 in the pattern PT5-2. The pattern PT5-2 has two lattice elements 223a and 223b. A half mirror element 226 is provided in place of the third grating element 223c. The positions and postures of the two lattice elements 223a and 223b are the same as those of the first lattice element 223a and the second lattice element 223b of the pattern PT5-1. The half mirror element 226 has the same position and orientation as the third grating element 223c of the pattern PT5-1. The arrangement of the light sources L is the same as the pattern PT5-1.

The surface of the first grating element 223a on which blue light is incident is the grating mirror surface 27, and the mirror 25 and the half mirror 26 are not vapor-deposited on the opposite surface. The second grating element 223b has a grating mirror surface 27 on the surface on which infrared light is incident, and the mirror 25 and the half mirror 26 are not deposited on the opposite surface.

The grating element 223a has glass 24 in the first section C1 and the second section C2, and mirrors 25 in the third section C3 and the fourth section C4. The grating element 223b has mirrors 25 in the first section C1 and the fourth section C4, and glass 24 in the second section C2 and the third section C3.

FIG. 36 shows the color of each section C output from the half mirror element 226 in pattern PT5-2. In pattern PT5-2, each color has the same phase as pattern PT3-2. Therefore, it can be seen that the pattern PT5-1 also produces a composite fringe pattern image that can be used in the color phase shift method.

In the pattern PT5-2, the half mirror element 226 is arranged at a position where the light output from the grating element 223a and the light output from the grating element 223b intersect. Therefore, since the half mirror element 226 and the two grating elements 223a and 223b are arranged orthogonally, it is possible to prevent the projector 20 from becoming longer in one direction.

Further, in this configuration, light from any light source L only needs to pass through the lattice element 223 and the half-mirror element 226 in a total number of two. Therefore, it is possible to reduce the extent to which the light from the light source L is attenuated when passing through the grating element 223 and the half mirror element 226 .

Although the embodiments have been described above, the disclosed technology is not limited to the above-described embodiments, and the following modifications are also included in the disclosed scope. It can be implemented with various modifications.

<Modification 1>
In the embodiment, the light sources L simultaneously emitted different colors. However, it is also possible to use light sources L that emit the same color as each other. If the light emission periods are made different from each other, the light sources L that emit light of the same color can be used.

<Modification 2>
In the first embodiment, the sixth section C6 of the grating element 23a was glass 24; However, the sixth section C6 of the grating element 23a may be a mirror 25 as well. This is because, since the sixth section C6 of the grating element 23b is the mirror 25, even if the light passes through the sixth section C6 of the grating element 23a, it is blocked by the sixth section C6 of the grating element 23b. If the sixth segment C6 of the grating element 23a is a mirror 25, both the sixth segment C6 and the first segment C1 of the next period of the grating element 23a are mirrors 25. FIG.

<Modification 3>
In the embodiment, when there are three light sources L, the two grating elements 23 have the same posture. However, even when there are three light sources L, the two lattice elements 23 may be rotated 90 degrees from each other as in the pattern PT5-1.

1: Three-dimensional shape measurement system 2: Workbench 5: Measurement object 10: Control device 20: Projector (projection device) 21: Projection lens 22: Condensing lens 23: Grating element 24: Glass 25: Mirror 26: Half mirror 27: Grating mirror surface (grating surface) 28: Grating half mirror surface (grating surface) 30: Camera 123: Grating element 223: Grating element 226: Half mirror L: Light source

Claims (7)

A projection device (20) for projecting a fringe pattern image onto the measurement object in order to measure the three-dimensional shape of the measurement object by a phase shift method,
at least three light sources (L);
a projection lens (21) for projecting the fringe pattern image;
A plurality of grating elements (23, 123, 223) having at least one face serving as grating planes (27, 28) on which mirrors (25) or half mirrors (26) are formed in a grid pattern. ,
A plurality of the grating elements are arranged in an optical path between the light source and the projection lens, and are positioned on both sides so that the light emitted by the light source is irradiated directly or through another grating element. placed and
The projection apparatus according to claim 1, wherein the half mirror or the mirror is formed in a lattice pattern so that the light emitted from the light source has a fringe pattern with different phases when passing through the projection lens. A projection device according to claim 1, comprising:
The projection device, wherein the at least three light sources are light sources emitting different colors from each other and emitting light at the same time. 3. A projection device according to claim 2, comprising:
As the light source, three light sources that emit red, green, and blue light are provided,
comprising two lattice elements;
The projection device, wherein light emitted by the light source emitting green light reaches the projection lens via two of the grating elements. A projection device according to claim 1, comprising:
The projection device, wherein the at least three light sources emit the same color with each other and have different emission periods. A projection device according to any one of claims 1, 2 and 4,
Equipped with four light sources,
comprising three grating elements (223);
Two of the four light sources emit light parallel to each other in a first direction, and the remaining two of the four light sources emit light parallel to each other in a second direction orthogonal to the first direction. illuminate the
the first grating element, the light in the first direction is incident on one surface and the light in the second direction is incident on the other surface;
The second grating element has one surface on which the light output in the first direction by the first grating element is incident, and the other surface on which the light in the second direction is emitted. Light different from the light incident on the grating element is incident,
The third grating element has one surface on which the light output in the second direction from the second grating element is incident, and the other surface on which the light in the first direction and the first direction is emitted. A projection device in which light other than the light incident on the grating element is incident. A projection device according to any one of claims 1, 2 and 4,
Equipped with four light sources,
comprising three grating elements (223);
Two of the four light sources emit light parallel to each other in a first direction, and the remaining two of the four light sources emit light parallel to each other in a second direction orthogonal to the first direction. illuminate the
one surface of the first grating element receives light in the first direction and the other surface receives light in the second direction;
In the second grating element, light in the first direction, which is different from the light incident on the first grating element, is incident on one surface, and the light in the second direction is incident on the other surface. is incident on the first grating element, and is different from the light incident on the first grating element;
The third grating element is arranged at a position where the light output by the first grating element and the light outputted by the second grating element intersect, and the first grating element is arranged in the first direction. light output by the second grating element is incident on one surface, and light output by the second grating element in the second direction is incident on the other surface. A projection device according to any one of claims 1, 2 and 4,
Equipped with four light sources,
comprising two grating elements (223);
Equipped with one half mirror element (226),
Two of the four light sources emit light parallel to each other in a first direction, and the remaining two of the four light sources emit light parallel to each other in a second direction orthogonal to the first direction. illuminate the
one surface of the first grating element receives light in the first direction and the other surface receives light in the second direction;
The second grating element has one surface on which the light in the first direction and different from the light incident on the first grating element is incident, and the other surface on which the second grating element is incident. light in a direction different from the light incident on the first grating element is incident,
The half-mirror element is arranged at a position where the light output from the first grating element and the light output from the second grating element intersect. light output in the direction of (2) is incident, and light output in the second direction by the second grating element is incident on the other surface.

Images