Projection device and control method

Abstract

To provide a projection device and a control method with which it is possible to shift a projection range while suppressing a decrease in projection quality.SOLUTION: A projection device 10 comprises a light source 21, a light modulation unit 22, a first mirror 51, a second mirror 52, a third mirror 53, a fourth mirror 54, and a projection optical system 23. The light source 21 emits light. The light modulation unit 22 modulates light from the light source 21. The first mirror 51, second mirror 52, third mirror 53 and fourth mirror 54 reflect the optical image modulated by the light modulation unit 22. The projection optical system 23 projects the optical image reflected by the first mirror 51, second mirror 52, third mirror 53 and fourth mirror 54 to the projection surface of a projection object 6. The first mirror 51, second mirror 52, third mirror 53 and fourth mirror 54 are arranged between the light modulation unit 22 and the projection optical system 23.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a projection apparatus and a control method. [Background technology]

[0002] Patent document 1 describes a projection display device in which each color light, the beam of which has been expanded by a beam expansion section, is incident on an integrator consisting of a fly's eye lens via a beam irradiation position displacement section, and the beam irradiation position displacement section displaces a mirror in parallel using a drive section to move the position of the laser light incident on the integrator.

[0003] Patent document 2 describes a projector that includes a light source unit that houses a light source, a projection unit that modulates the light emitted from the light source unit to form an image and projects the formed image, and a light guide path that guides the light emitted from the light source unit to the projection unit, in which the light guide path includes a plurality of sliding members that allow the distance between the light source unit and the projection unit to be changed.

[0004] Patent document 3 describes a projection display system in which the direction of light from an optical modulation element that has passed through a relay lens is changed by a first mirror and a second mirror, and the light passes through a lens and is projected onto a screen, the projection display system being equipped with mirror rotation that changes the inclination of the second mirror. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-152384 A [Patent Document 2] JP 2018-169426 A [Patent Document 3] JP 2020-027117 A Summary of the Invention

[0006] An embodiment of the technique disclosed herein provides a projection device and a control method that are capable of shifting the projection range while suppressing degradation of projection quality. [Means for solving the problem]

[0007] A projection device of one embodiment of the present invention comprises an irradiation unit that irradiates light, an optical modulation element that modulates the light from the irradiation unit, a plurality of reflecting units that reflect an optical image modulated by the optical modulation element, and a projection optical system that projects the optical image reflected by the plurality of reflecting units onto a projection surface, wherein the plurality of reflecting units are disposed between the optical modulation element and the projection optical system.

[0008] A control method of one embodiment of the present invention is a control method using a projection device including an irradiation unit that irradiates light, a light modulation element that modulates the light from the irradiation unit, a plurality of reflection units that reflect the optical image modulated by the light modulation element, a projection optical system that projects the optical image reflected by the plurality of reflection units onto a projection surface, and a processor, wherein the plurality of reflection units are disposed between the light modulation element and the projection optical system, and the processor performs control to change the position of the projection range of the optical image by displacing at least one of the plurality of reflection units. Effect of the Invention

[0009] According to the present invention, it is possible to provide a projection device and a control method that are capable of shifting the projection range while suppressing deterioration of the projection quality. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a schematic configuration of a projection device 10 according to an embodiment. [Diagram 2] 2 is a schematic diagram showing an example of an internal configuration of a projection unit 1 shown in FIG. [Diagram 3] FIG. 1 is a schematic diagram showing the external configuration of a projection device 10. [Figure 4]4 is a schematic cross-sectional view of an optical unit 106 of the projection device 10 shown in FIG. [Diagram 5] 4A to 4C are diagrams illustrating a first configuration example of a second shift mechanism 50. [Figure 6] 6 is a diagram showing an example of shifting of the projection range 11 by the second shift mechanism 50 shown in FIG. 5. FIG. [Figure 7] 11 is a diagram showing a second configuration example of the second shift mechanism 50. FIG. [Figure 8] 8 is a diagram showing an example of shifting of the projection range 11 by the second shift mechanism 50 shown in FIG. 7. FIG. [Figure 9] 11 is a diagram illustrating a third configuration example of the second shift mechanism 50. FIG. [Figure 10] 10 is a diagram showing an example of shifting of the projection range 11 by the second shift mechanism 50 shown in FIG. 9. FIG. [Figure 11] 13 is a diagram showing a fourth configuration example of the second shift mechanism 50. FIG. [Figure 12] 12 is a diagram showing an example of shifting of the projection range 11 in the y direction by the second shift mechanism 50 shown in FIG. 11. FIG. [Figure 13] 12 is a diagram showing an example of shifting of the projection range 11 in the direction z by the second shift mechanism 50 shown in FIG. [Figure 14] 12 is a diagram showing another example of the shift of the projection range 11 in the direction y by the second shift mechanism 50 shown in FIG. [Figure 15] 12 is a diagram showing another example of the shift of the projection range 11 in the direction z by the second shift mechanism 50 shown in FIG. [Figure 16] 11 is a diagram showing a fifth configuration example of a second shift mechanism 50. FIG. [Figure 17] FIG. 1 is a diagram showing an example of dual-screen projection by a projection device 10. [Figure 18] FIG. 1 is a diagram showing an example of the configuration of a projection device 10 that performs dual screen projection. [Figure 19] 19 is a diagram showing an example of shifting of the projection range 11 by the second shift mechanism 50 shown in FIG. 18. FIG. [Figure 20] FIG. 11 is a diagram showing another example of the configuration of the projection device 10 performing dual screen projection. [Figure 21] FIG. 13 is a diagram showing another example of dual-screen projection by the projection device 10. [Figure 22] 13 is a schematic diagram showing another external configuration of the projection device 10. FIG. [Figure 23] 23 is a schematic cross-sectional view of an optical unit 106 of the projection device 10 shown in FIG. 22. [Figure 24] 13 is a diagram showing, for reference, an example of the configuration of the second shift mechanism 50 that cannot maintain the air-equivalent length when the projection range 11 is shifted. FIG. [Diagram 25] 25 is a diagram showing, for reference, an example of shifting of the projection range 11 by the second shift mechanism 50 shown in FIG. 24. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

[0012] (Embodiment) <Overall configuration of the projection device 10 according to the embodiment> FIG. 1 is a schematic diagram showing a schematic configuration of a projection device 10 according to an embodiment.

[0013] The projection device 10 includes a projection unit 1, a control device 4, and an operation reception unit 2. The projection unit 1 is configured by, for example, a liquid crystal projector or a projector using LCOS (Liquid Crystal On Silicon). In the following, the projection unit 1 will be described as being a liquid crystal projector.

[0014] The control device 4 controls the projection by the projection device 10. The control device 4 is a device including a control unit configured with various processors, a communication interface (not shown) for communicating with each unit, and a storage medium 4a such as a hard disk, a solid state drive (SSD) or a read only memory (ROM), and controls the projection unit 1. The various processors of the control unit of the control device 4 include a CPU (Central Processing Unit), which is a general-purpose processor that executes a program and performs various processes, a programmable logic device (PLD), which is a processor whose circuit configuration can be changed after manufacture such as an FPGA (Field Programmable Gate Array), or a dedicated electric circuit, which is a processor having a circuit configuration designed specifically for executing specific processes such as an ASIC (Application Specific Integrated Circuit), and the like.

[0015] More specifically, the structure of these various processors is an electric circuit that combines circuit elements such as semiconductor elements. The control unit of the control device 4 may be composed of one of the various processors, or may be composed of a combination of two or more processors of the same or different types (for example, a combination of multiple FPGAs or a combination of a CPU and an FPGA).

[0016] The operation reception unit 2 detects instructions from the user (user instructions) by receiving various operations from the user. In this embodiment, the operation reception unit 2 is an operation unit such as a button, a key, a joystick, etc. provided on the main body of the projection device 10. Therefore, when the operation reception unit 2 is operated, it can be determined that the user is located near the projection device 10.

[0017] The projection object 6 is an object such as a screen having a projection surface on which a projected image is displayed by the projection unit 1. In the example shown in Fig. 1, the projection surface of the projection object 6 is a rectangular plane. The top, bottom, left and right of the projection object 6 in Fig. 1 are assumed to be the top, bottom, left and right of the actual projection object 6.

[0018] A projection range 11, shown by a dashed line, is a region of the projection object 6 onto which projection light is irradiated by the projection unit 1. In the example shown in Fig. 1, the projection range 11 is rectangular. The projection range 11 is a part or the entirety of a projectable range onto which projection by the projection unit 1 can project.

[0019] The projection unit 1, the control device 4, and the operation reception unit 2 may be realized, for example, by a single device (see, for example, FIGS. 3 and 4). Alternatively, the projection unit 1, the control device 4, and the operation reception unit 2 may be separate devices that communicate with each other to cooperate with each other.

[0020] <Internal configuration of the projection unit 1 shown in FIG. 1> FIG. 2 is a schematic diagram showing an example of the internal configuration of the projection unit 1 shown in FIG.

[0021] 2, the projection unit 1 includes a light source 21, a light modulation unit 22, a projection optical system 23, and a control circuit 24. The light source 21 includes a light emitting element such as a laser or an LED (Light Emitting Diode), and emits, for example, white light. The light source 21 is an example of an irradiation unit that irradiates light.

[0022] The light modulation unit 22 is composed of three liquid crystal panels (light modulation elements) that modulate the three color lights emitted from the light source 21 and separated into red, blue, and green by a color separation mechanism not shown based on image information to emit each color image, and a dichroic prism that mixes the color images emitted from the three liquid crystal panels and emits them in the same direction. Red, blue, and green filters may be mounted on each of the three liquid crystal panels, and the white light emitted from the light source 21 may be modulated by each liquid crystal panel to emit each color image.

[0023] The projection optical system 23 receives light from the light source 21 and the light modulation unit 22 and includes at least one lens, and is configured, for example, by a relay optical system. The light that passes through the projection optical system 23 is projected onto the projection object 6.

[0024] An area of ​​the projection object 6 that is irradiated with light that transmits through the entire range of the light modulation unit 22 becomes a projectable range where projection by the projection unit 1 is possible. Within this projectable range, an area that is irradiated with light that actually transmits from the light modulation unit 22 becomes a projection range 11. For example, by controlling the size, position, and shape of the area of ​​the light modulation unit 22 through which light transmits, the size, position, and shape of the projection range 11 change within the projectable range.

[0025] The control circuit 24 controls the light source 21, the light modulation unit 22, and the projection optical system 23 based on the display data input from the control device 4, thereby projecting an image based on the display data onto the projection object 6. The display data input to the control circuit 24 is composed of three data: red display data, blue display data, and green display data.

[0026] Furthermore, the control circuit 24 enlarges or reduces the projection range 11 (see FIG. 1 ) of the projection unit 1 by changing the projection optical system 23 based on a command input from the control device 4. The control device 4 may also move the projection range 11 of the projection unit 1 by changing the projection optical system 23 based on an operation from a user accepted by the operation accepting unit 2.

[0027] The projection device 10 also includes a shift mechanism that mechanically or optically moves the projection range 11 while maintaining the image circle of the projection optical system 23. The image circle of the projection optical system 23 is an area where the projection light incident on the projection optical system 23 passes through the projection optical system 23 appropriately in terms of light amount drop, color separation, peripheral curvature, etc.

[0028] The shift mechanism is realized by at least one of an optical system shift mechanism that performs an optical system shift and an electronic shift mechanism that performs an electronic shift.

[0029] The optical system shift mechanism is, for example, a mechanism for moving the projection optical system 23 in a direction perpendicular to the optical axis (see, for example, FIGS. 3 and 4), or a mechanism for moving the light modulation unit 22 in a direction perpendicular to the optical axis instead of moving the projection optical system 23. The optical system shift mechanism may also be a mechanism for combining the movement of the projection optical system 23 and the movement of the light modulation unit 22.

[0030] The electronic shift mechanism is a mechanism for shifting the pseudo projection range 11 by changing the range through which light is transmitted in the light modulation section 22 .

[0031] The projection device 10 may also include a projection direction change mechanism that moves the projection range 11 together with the image circle of the projection optical system 23. The projection direction change mechanism is a mechanism that changes the projection direction of the projection unit 1 by changing the orientation of the projection unit 1 through mechanical rotation (see, for example, FIGS. 3 and 4).

[0032] <Mechanical configuration of the projection device 10> Fig. 3 is a schematic diagram showing the external configuration of the projection device 10. Fig. 4 is a schematic cross-sectional view of the optical unit 106 of the projection device 10 shown in Fig. 3. Fig. 4 shows a cross section taken along a plane along the optical path of light emitted from the main body 101 shown in Fig. 3.

[0033] 3, the projection device 10 includes a main body 101 and an optical unit 106 protruding from the main body 101. In the configuration shown in FIG. 3, the operation reception unit 2, the control device 4, and the light source 21, light modulation unit 22, and control circuit 24 in the projection unit 1 are provided in the main body 101. The projection optical system 23 in the projection unit 1 is provided in the optical unit 106.

[0034] The optical unit 106 includes a first member 102 supported by a main body 101 and a second member 103 supported by the first member 102 .

[0035] The first member 102 and the second member 103 may be an integrated member. The optical unit 106 may be configured to be detachable from the main body 101 (in other words, configured to be replaceable).

[0036] The main body 101 has a housing 15 (see FIG. 4) in which an opening 15a (see FIG. 4) for passing light is formed at a portion connected to the optical unit .

[0037] As shown in FIG. 3, provided inside the housing 15 of the main body 101 are a light source 21 and a light modulation unit 12 including a light modulation section 22 (see FIG. 2) that spatially modulates the light emitted from the light source 21 based on input image data to generate an image.

[0038] The light emitted from the light source 21 is incident on the light modulation section 22 of the light modulation unit 12, and is spatially modulated by the light modulation section 22 before being emitted.

[0039] As shown in FIG. 4, the image formed by the light spatially modulated by the light modulation unit 12 passes through the opening 15a of the housing 15 and enters the optical unit 106, and is projected onto the projection object 6 as the projection target, so that the image G1 becomes visible to the observer.

[0040] As shown in FIG. 4, the optical unit 106 includes a first member 102 having a hollow portion 2A connected to the inside of the main body 101, a second member 103 having a hollow portion 3A connected to the hollow portion 2A, a first optical system 121 and a reflecting member 122 arranged in the hollow portion 2A, a second optical system 31, a reflecting member 32, a third optical system 33, and a lens 34 arranged in the hollow portion 3A, a first shift mechanism 105, and a projection direction change mechanism 104.

[0041] The first member 102 is a member having a cross-sectional outer shape of, for example, a rectangle, and the openings 2a and 2b are formed on planes perpendicular to each other. The first member 102 is supported by the main body 101 with the opening 2a disposed at a position facing the opening 15a of the main body 101. Light emitted from the optical modulation section 22 of the optical modulation unit 12 of the main body 101 passes through the openings 15a and 2a and enters the hollow section 2A of the first member 102.

[0042] The incident direction of light entering hollow portion 2A from main body portion 101 is referred to as direction X1, the opposite direction to direction X1 is referred to as direction X2, and directions X1 and X2 are collectively referred to as direction X. In addition, in Fig. 4, the direction from the front of the paper to the back and the opposite direction thereto are referred to as direction Z. Of direction Z, the direction from the front of the paper to the back is referred to as direction Z1, and the direction from the back of the paper to the front is referred to as direction Z2.

[0043] Moreover, a direction perpendicular to directions X and Z is referred to as direction Y, and within direction Y, the upward direction in Fig. 4 is referred to as direction Y1, and the downward direction in Fig. 4 is referred to as direction Y2. In the example of Fig. 4, the projection device 10 is disposed so that direction Y2 is the vertical direction.

[0044] The projection optical system 23 shown in Fig. 2 is composed of a first optical system 121, a reflecting member 122, a second optical system 31, a reflecting member 32, a third optical system 33, and a lens 34. Fig. 4 shows an optical axis K of the projection optical system 23. The first optical system 121, the reflecting member 122, the second optical system 31, the reflecting member 32, the third optical system 33, and the lens 34 are arranged along the optical axis K in this order from the light modulation unit 22 side.

[0045] The first optical system 121 includes at least one lens, and guides light traveling in a direction X1 that is incident on the first member 102 from the main body 101 to the reflecting member 122.

[0046] The reflecting member 122 reflects the light incident from the first optical system 121 in a direction Y1. The reflecting member 122 is formed of, for example, a mirror. The first member 102 has an opening 2b formed on the optical path of the light reflected by the reflecting member 122. The reflected light passes through the opening 2b and advances to the hollow portion 3A of the second member 103.

[0047] The second member 103 is a member having a substantially T-shaped cross-sectional outline, and has an opening 3a formed at a position facing the opening 2b of the first member 102. Light from the main body 101 that has passed through the opening 2b of the first member 102 passes through this opening 3a and enters the hollow portion 3A of the second member 103. The cross-sectional outlines of the first member 102 and the second member 103 are arbitrary and are not limited to those described above.

[0048] The second optical system 31 includes at least one lens, and guides the light incident from the first member 102 to the reflecting member 32 .

[0049] The reflecting member 32 reflects the light incident from the second optical system 31 in a direction X2 and guides the light to the third optical system 33. The reflecting member 32 is formed of, for example, a mirror.

[0050] The third optical system 33 includes at least one lens, and guides the light reflected by the reflecting member 32 to a lens .

[0051] The lens 34 is disposed at the end of the second member 103 in the direction X2 so as to cover the opening 3c formed at this end. The lens 34 projects the light incident from the third optical system 33 onto the projection object 6.

[0052] The projection direction change mechanism 104 is a rotation mechanism that rotatably connects the second member 103 to the first member 102. The projection direction change mechanism 104 configures the second member 103 to be rotatable around a rotation axis (specifically, optical axis K) extending in direction Y. Note that the projection direction change mechanism 104 is not limited to the arrangement position shown in FIG. 4 as long as it can rotate the optical system. Furthermore, the number of rotation mechanisms is not limited to one, and multiple mechanisms may be provided.

[0053] The first shift mechanism 105 is a mechanism for moving the optical axis K of the projection optical system (in other words, the optical unit 106) in a direction perpendicular to the optical axis K (direction Y in FIG. 4). Specifically, the first shift mechanism 105 is configured to be able to change the position of the first member 102 in direction Y relative to the main body 101. The first shift mechanism 105 may be one that moves the first member 102 manually, or one that moves the first member 102 electrically.

[0054] Fig. 4 shows a state in which the first member 102 is moved to the maximum extent in the direction Y1 by the first shift mechanism 105. When the first member 102 is moved in the direction Y2 by the first shift mechanism 105 from the state shown in Fig. 4, the relative position between the center of the image formed by the light modulation unit 22 (in other words, the center of the display surface) and the optical axis K changes, and the image G1 projected onto the projection object 6 can be shifted (translated) in the direction Y2.

[0055] The first shift mechanism 105 may be a mechanism that moves the light modulation section 22 in the direction Y, instead of moving the optical unit 106 in the direction Y. Even in this case, the image G1 projected onto the projection object 6 can be moved in the direction Y2.

[0056] 4, the projection device 10 includes a second shift mechanism 50 in addition to the first shift mechanism 105. The second shift mechanism 50 is provided between the light modulation unit 22 and the projection optical system 23 (the first optical system 121, the reflecting member 122, the second optical system 31, the reflecting member 32, the third optical system 33, and the lens 34). In the example of FIG. 4, the second shift mechanism 50 is provided in a position in the main body 101 between the light modulation unit 22 and the opening 15a.

[0057] The second shift mechanism 50 has a plurality of reflecting parts as described below, and by displacing at least one of these reflecting parts, the position of the image G1 projected onto the projection object 6, i.e., the projection range of the optical image, can be changed.

[0058] <Configuration Example 1 of Second Shift Mechanism 50> Fig. 5 is a diagram showing a first configuration example of the second shift mechanism 50. In Fig. 5, the projection optical system 23 is illustrated in a simplified form. The dichroic prism 22a shown in Fig. 5 is the above-mentioned dichroic prism provided in the light modulation unit 22. The dichroic prism 22a is an example of a prism provided between a plurality of reflecting units (a first mirror 51, a second mirror 52, a third mirror 53, and a fourth mirror 54 described below) and a liquid crystal panel (light modulation element) of the light modulation unit 22.

[0059] The incident direction of light (optical image) entering the second shift mechanism 50 from the dichroic prism 22a is described as direction x1, the opposite direction to direction x1 is described as direction x2, and directions x1 and x2 are collectively referred to as direction x. The directions x, x1, and x2 correspond to the directions X, X1, and X2 in FIG. 4 at the positions of the dichroic prism 22a and the second shift mechanism 50, respectively.

[0060] 5, the direction from the front of the paper to the back and the opposite direction are referred to as direction z. Of the z directions, the direction from the front of the paper to the back is referred to as direction z1, and the direction from the back of the paper to the front is referred to as direction z2. The directions z, z1, and z2 correspond to the directions Z, Z1, and Z2 in FIG. 4 at the positions of the dichroic prism 22a and the second shift mechanism 50, respectively.

[0061] Moreover, a direction perpendicular to the directions x and z is referred to as a direction y, and among the directions y, an upward direction in Fig. 5 is referred to as a direction y1, and a downward direction in Fig. 5 is referred to as a direction y2. The directions y, y1, and y2 correspond to the directions Y, Y1, and Y2 in Fig. 4 at the positions of the dichroic prism 22a and the second shift mechanism 50, respectively.

[0062] 5, the second shift mechanism 50 includes a first mirror 51, a second mirror 52, a third mirror 53, and a fourth mirror 54. The first mirror 51, the second mirror 52, the third mirror 53, and the fourth mirror 54 are examples of a plurality of reflecting portions. The first mirror 51, the second mirror 52, the third mirror 53, and the fourth mirror 54 are formed, for example, by applying silver, aluminum, or the like to the surface of a substrate made of resin or the like.

[0063] The first mirror 51 reflects the light emitted in the direction x1 from the dichroic prism 22a at an incident angle (reflection angle) of 45 degrees and emits the light in the direction y1.

[0064] The second mirror 52 reflects the light emitted from the first mirror 51 in the direction y1 at an incident angle of 45 degrees and emits it in the direction x2. The third mirror 53 reflects the light emitted from the second mirror 52 in the direction x2 at an incident angle of 45 degrees and emits it in the direction y1. The fourth mirror 54 reflects the light emitted from the third mirror 53 in the direction y1 at an incident angle of 45 degrees and emits it in the direction x1.

[0065] The light emitted from the fourth mirror 54 is projected as an image G1 by the projection optical system 23. For example, in the configuration example shown in Fig. 4, the light emitted from the fourth mirror 54 is projected as an image G1 onto the projection object 6 via the first optical system 121, the reflecting member 122, the second optical system 31, the reflecting member 32, the third optical system 33, and the lens 34.

[0066] 5, the first mirror 51 and the second mirror 52 are fixed in position relative to the dichroic prism 22a and the projection optical system 23. On the other hand, the third mirror 53 and the fourth mirror 54 are variable in position relative to the dichroic prism 22a and the projection optical system 23. Specifically, the third mirror 53 is displaceable in direction x, and the fourth mirror 54 is displaceable in directions x and y. The third mirror 53 and the fourth mirror 54 are displaced by the control device 4 controlling an actuator (e.g., a motor) (not shown) provided in the second shift mechanism 50.

[0067] A is the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 in the state of Fig. 5. The air-equivalent length of the optical path is expressed by a value (length / refractive index) obtained by dividing the length of the optical path in the direction in which light passes by the refractive index of the optical path. In the example of Fig. 5, there is air (refractive index = 1) between the first mirror 51, the second mirror 52, the third mirror 53, and the fourth mirror 54, and the air-equivalent length of the optical path is the length (distance) of the optical path in the direction in which light passes.

[0068] 5. A point on the optical path from the fourth mirror 54 to the projection optical system 23, whose position in the direction x coincides with the incident position of light on the second mirror 52, is defined as imaginary point 55. In this case, the air-equivalent length of the optical path from the fourth mirror 54 to imaginary point 55 is also A. Therefore, the air-equivalent length of the optical path from the second mirror 52 to imaginary point 55 is A+B+A=2A+B.

[0069] The control device 4 performs control to displace the first mirror 51 and the second mirror 52, thereby shifting the position of the image G1 (that is, the position of the projection range 11).

[0070] <Shifting of the projection range 11 by the second shift mechanism 50 shown in FIG. 5> Fig. 6 is a diagram showing an example of shifting of the projection range 11 by the second shift mechanism 50 shown in Fig. 5. In the example of Fig. 6, the control device 4 controls the third mirror 53 to be displaced in the direction x2 and the fourth mirror 54 to be displaced in the directions x2 and y2. This makes it possible to shift the image G1 (i.e., the projection range 11) in the direction y2.

[0071] In addition, the control device 4 not only displaces the fourth mirror 54 in the direction y2, but also controls the third mirror 53 and the fourth mirror 54 to be displaced in the direction x2, thereby suppressing the change in the air-equivalent length of the optical path between the dichroic prism 22a and the projection optical system 23 that accompanies the displacement of the image G1.

[0072] Specifically, in the example shown in Fig. 6, the control device 4 performs control to displace the third mirror 53 and the fourth mirror 54 by Δ in the direction x2, and to displace the fourth mirror 54 by 2Δ in the direction y2. In this case, compared to the state in Fig. 5, the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 increases by Δ, the air-equivalent length of the optical path from the third mirror 53 to the fourth mirror 54 decreases by 2Δ, and the air-equivalent length of the optical path from the fourth mirror 54 to the virtual point 55 increases by Δ.

[0073] Therefore, in the example of Fig. 6, the air-equivalent length of the optical path from the second mirror 52 to the virtual point 55 is (A+Δ)+(B-2Δ)+(A+Δ)=2A+B, which is the same as the state of Fig. 5. Also, in the examples of Fig. 5 and 6, the air-equivalent length from the dichroic prism 22a to the second mirror 52 and the air-equivalent length from the virtual point 55 to the projection optical system 23 are unchanged.

[0074] Therefore, even if the state of Fig. 5 is shifted to the state of Fig. 6 and the image G1 is shifted in the direction y, the air-equivalent length of the optical path between the dichroic prism 22a and the projection optical system 23 can be maintained. This makes it possible to suppress unintended defocusing (e.g., blurring) of the image G1 caused by a change in the imaging position of the image G1 in the direction x. Therefore, the projection range 11 can be shifted while suppressing a decrease in projection quality.

[0075] 6, the third mirror 53 is displaced in the direction x2, the fourth mirror 54 is displaced in the direction x2, and the fourth mirror 54 is displaced in the direction y2. However, these displacements may be performed sequentially in any order, or may be performed in parallel. Moreover, the image G1 can be shifted in the direction y1 by displacing the third mirror 53 and the fourth mirror 54 in the opposite direction to that in the example of FIG. 6.

[0076] In this manner, in the projection device 10, the first mirror 51, the second mirror 52, the third mirror 53, and the fourth mirror 54 (multiple reflecting sections) that reflect the optical image modulated by the light modulation section 22 are disposed between the light modulation section 22 and the projection optical system 23. This makes it possible to change (shift) the position of the projection range 11 by controlling the displacement of at least one of the first mirror 51, the second mirror 52, the third mirror 53, and the fourth mirror 54 (the third mirror 53 and the fourth mirror 54 in the example of FIG. 6).

[0077] Furthermore, the control device 4 performs this control so that the air-equivalent length of the path of the optical image between the light modulation unit 22 and the projection optical system 23 becomes a specific value (for example, the air-equivalent length of the optical path from the light modulation unit 22 to the projection optical system 23 in Figs. 5 and 6), thereby making it possible to suppress unintended defocusing (for example, blurring) of the image G1 due to the shift of the projection range 11. Therefore, it is possible to shift the projection range 11 while suppressing deterioration of the projection quality.

[0078] For example, the operation receiving unit 2 is a setting unit that sets the position of the projection range 11. For example, the operation receiving unit 2 receives a designation of the position of the projection range 11 from a user by a key or the like, and sets the received position of the projection range 11 as the position of the projection range 11 to which the projection range 11 is shifted. The control device 4 performs the above-mentioned control for shifting the projection range 11 based on the position of the projection range 11 set by the operation receiving unit 2.

[0079] However, the setting unit that sets the position of the projection range 11 is not limited to the operation receiving unit 2. For example, the projection device 10 may include an imaging device capable of capturing an image of the projection target object 6, and the control device 4 may automatically set the position of the projection range 11 based on an image captured by the imaging device. In this case, the imaging device and the control device 4 serve as a setting unit that sets the position of the projection range 11.

[0080] <Maintaining the air-equivalent length of the optical path> The control device 4 may perform the above control for shifting the projection range 11 while maintaining the air-equivalent length of the optical path between the light modulation unit 22 and the projection optical system 23. The state in which the air-equivalent length of the optical path is maintained means a state in which the change in the air-equivalent length of the optical path is reduced to an extent that the defocus of the image G1 caused by the change in the air-equivalent length of the optical path is not clearly recognized by the user.

[0081] Specifically, even during control to change from the state in FIG. 5 to the state in FIG. 6, the control device 4 displaces the third mirror 53 and the fourth mirror 54 in coordination, thereby maintaining the air-equivalent length of the optical path from the second mirror 52 to the virtual point 55 at 2A+B.

[0082] For example, in order to transition from the state of Fig. 5 to the state of Fig. 6, the control device 4 simultaneously displaces the third mirror 53 by Δ in the direction x2, the fourth mirror 54 by Δ in the direction x2, and the fourth mirror 54 by 2Δ in the direction y2 over the same amount of time. At this time, the speeds of the displacements of the third mirror 53 and the fourth mirror 54 in the direction x2 are both set to V, and the speed of the displacement of the fourth mirror 54 by 2Δ in the direction y2 is set to V2. This allows the state of Fig. 5 to transition to the state of Fig. 6 while maintaining the air-equivalent length of the optical path from the second mirror 52 to the virtual point 55 at 2A+B.

[0083] Alternatively, in order to transition from the state of FIG. 5 to the state of FIG. 6, the control device 4 may repeat N times the displacement of the third mirror 53 in the direction x2 by Δ / N, the displacement of the fourth mirror 54 in the direction x2 by Δ / N, and the displacement of the fourth mirror 54 in the direction y2 by 2Δ / N, which are regarded as one process. N is a natural number of 2 or more. The larger N is, the smaller the variation in the air-equivalent length of the optical path from the second mirror 52 to the virtual point 55 due to one process can be, and the user can be prevented from clearly noticing the defocus of the image G1. In this way, by repeatedly performing the process of sequentially displacing the third mirror 53 and the fourth mirror 54, the state of FIG. 5 can be transitioned to the state of FIG. 6 while maintaining the air-equivalent length of the optical path from the second mirror 52 to the virtual point 55 at approximately 2A+B, without performing each displacement simultaneously.

[0084] Next, other configuration examples of the second shift mechanism 50 will be described.

[0085] <Configuration Example 2 of Second Shift Mechanism 50> Fig. 7 is a diagram showing a second configuration example of the second shift mechanism 50. In the example shown in Fig. 7, the fourth mirror 54 is displaceable only in the direction y.

[0086] <Shifting of the projection range 11 by the second shift mechanism 50 shown in FIG. 7> Fig. 8 is a diagram showing an example of shifting of the projection range 11 by the second shift mechanism 50 shown in Fig. 7. In the example of Fig. 8, the control device 4 controls the third mirror 53 to be displaced in the direction x2 and the fourth mirror 54 to be displaced in the direction y2. This makes it possible to shift the image G1 (i.e., the projection range 11) in the direction y2.

[0087] Specifically, the control device 4 performs control to displace the third mirror 53 by Δ in the direction x2, and displace the fourth mirror 54 by Δ in the direction y2. In this case, the incident position of light on the fourth mirror 54 shifts by Δ in the direction x2 and by Δ in the direction y2. As a result, compared to the state of Fig. 7, the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 increases by Δ, the air-equivalent length of the optical path from the third mirror 53 to the fourth mirror 54 decreases by 2Δ, and the air-equivalent length of the optical path from the fourth mirror 54 to the virtual point 55 increases by Δ.

[0088] Therefore, in the example of Fig. 8, the air-equivalent length of the optical path from the second mirror 52 to the virtual point 55 is (A+Δ)+(B-2Δ)+(A+Δ)=2A+B, which is the same as the state of Fig. 7. Therefore, similarly to the configuration examples of Figs. 5 and 6, even if the image G1 is shifted in the direction y, the air-equivalent length of the optical path between the dichroic prism 22a and the projection optical system 23 can be maintained. This makes it possible to suppress unintended blurring of the image G1 caused by a change in the imaging position of the image G1 in the direction x, and to shift the projection range 11 while suppressing a decrease in the projection quality.

[0089] In the configuration examples of FIGS. 7 and 8, the incident position of light on the fourth mirror 54 shifts, so the area of ​​the reflecting surface of the fourth mirror 54 is designed to enable this shift.

[0090] <Configuration Example 3 of Second Shift Mechanism 50> Fig. 9 is a diagram showing a third configuration example of the second shift mechanism 50. In the example shown in Fig. 9, the second shift mechanism 50 includes fourth mirrors 54a and 54b instead of the fourth mirror 54 shown in Figs. 5 to 8. The positions of the fourth mirrors 54a and 54b relative to the dichroic prism 22a and the projection optical system 23 are fixed.

[0091] As shown in Fig. 9, the fourth mirror 54a is provided at a position where it reflects the light from the third mirror 53 at the same position as the fourth mirror 54 shown in Fig. 5 when the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 is A. In contrast, the fourth mirror 54b is provided at a position where it reflects the light from the third mirror 53 at the same position as the fourth mirror 54 shown in Fig. 6 when the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 is A+Δ (see Fig. 10).

[0092] <Shifting of the projection range 11 by the second shift mechanism 50 shown in FIG. 9> Fig. 10 is a diagram showing an example of shifting of the projection range 11 by the second shift mechanism 50 shown in Fig. 9. In the example of Fig. 10, the control device 4 controls the third mirror 53 to be displaced in the direction x2. This makes it possible to shift the image G1 (i.e., the projection range 11) in the direction y2.

[0093] Specifically, the control device 4 performs control to displace the third mirror 53 by Δ in the direction x2. In this case, a state transition occurs from one in which the light from the third mirror 53 is incident on the fourth mirror 54a to one in which the light from the third mirror 53 is incident on the fourth mirror 54b. As a result, compared to the state of Fig. 9, the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 increases by Δ, the air-equivalent length of the optical path from the third mirror 53 to the fourth mirror 54a or the fourth mirror 54b decreases by 2Δ, and the air-equivalent length of the optical path from the fourth mirror 54 to the virtual point 55 increases by Δ.

[0094] 10, the air-equivalent length of the optical path from the second mirror 52 to the virtual point 55 is (A+Δ)+(B-2Δ)+(A+Δ)=2A+B, which is the same as the state in FIG. 9. Therefore, similar to the configuration examples in FIGS. 5 and 6 and the configuration examples in FIGS. 7 and 8, even if the image G1 is shifted in the direction y, the air-equivalent length of the optical path between the dichroic prism 22a and the projection optical system 23 can be maintained. This makes it possible to suppress unintended blurring of the image G1 caused by a change in the imaging position of the image G1 in the direction x, and to shift the projection range 11 while suppressing a decrease in projection quality.

[0095] 9 and 10, the air-equivalent length of the optical path between the dichroic prism 22a and the projection optical system 23 can be maintained when the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 is A and when the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 is A+Δ. Therefore, as the position of the image G1 (projection range 11), it is possible to set a position where the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 is A and a position where the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 is A+Δ, but not to set a position where the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 is between A and A+Δ.

[0096] <Configuration Example 4 of Second Shift Mechanism 50> Fig. 11 is a diagram showing a fourth configuration example of the second shift mechanism 50. In Fig. 11, a configuration capable of shifting the projection range 11 in the direction y and the direction z will be described. In the example shown in Fig. 11, the second shift mechanism 50 includes a first mirror 151, a second mirror 152, a third mirror 153, and a fourth mirror 154. The first mirror 151, the second mirror 152, the third mirror 153, and the fourth mirror 154 are formed, for example, by applying silver, aluminum, or the like to the surface of a substrate made of resin or the like.

[0097] The first mirror 151 reflects the light emitted in the direction x1 from the dichroic prism 22a at an incident angle (reflection angle) of 45 degrees and emits the light in the direction z1.

[0098] The second mirror 152 reflects the light emitted from the first mirror 151 in direction z1 at an incident angle of 45 degrees and emits it in direction x2. The third mirror 153 reflects the light emitted from the second mirror 152 in direction x2 at an incident angle of 45 degrees and emits it in direction y1. The fourth mirror 154 reflects the light emitted from the third mirror 153 in direction y1 at an incident angle of 45 degrees and emits it in direction x1. The light emitted from the fourth mirror 154 is projected by the projection optical system 23 as an image G1.

[0099] The fourth mirror 154 is an example of a first reflecting section for changing the position of the projection range 11 in the direction y (first direction). The second mirror 152 is an example of a second reflecting section for changing the position of the projection range 11 in the direction z (second direction).

[0100] 11, the positions of the first mirror 151, the second mirror 152, the third mirror 153, and the fourth mirror 154 are variable relative to the dichroic prism 22a and the projection optical system 23. Specifically, the first mirror 151, the second mirror 152, and the third mirror 153 are displaceable in the direction x and the direction z, and the fourth mirror 154 is displaceable in the direction y and the direction x. The displacement of the first mirror 151, the second mirror 152, the third mirror 153, and the fourth mirror 154 is performed by the control device 4 controlling an actuator (e.g., a motor) (not shown) provided in the second shift mechanism 50.

[0101] A is the air-equivalent length of the optical path from the dichroic prism 22a to the first mirror 151 in the state of FIG. 11. B is the air-equivalent length of the optical path from the first mirror 151 to the second mirror 152 in the state of FIG. 11. C is the air-equivalent length of the optical path from the second mirror 152 to the third mirror 153 in the state of FIG. 11. D is the air-equivalent length of the optical path from the third mirror 153 to the fourth mirror 154 in the state of FIG. 11. E is the air-equivalent length of the optical path from the fourth mirror 154 to the projection optical system 23 in the state of FIG. 11. In this case, the air-equivalent length of the optical path from the dichroic prism 22a to the projection optical system 23 is A+B+C+D+E.

[0102] The control device 4 changes (shifts) the position of the image G1 (i.e., the projection range 11) in the directions y and z by controlling the displacement of the first mirror 151, the second mirror 152, the third mirror 153, and the fourth mirror 154.

[0103] <Shifting of the projection range 11 in the direction y by the second shift mechanism 50 shown in FIG. 11> Fig. 12 is a diagram showing an example of the shift of the projection range 11 in the direction y by the second shift mechanism 50 shown in Fig. 11. Fig. 12 shows the second mirror 152, the third mirror 153, the fourth mirror 154, and the projection optical system 23 before and after the shift of the projection range 11 in the direction y, as viewed from the direction z2 toward the direction z1.

[0104] The upper part of Fig. 12 shows the state before the projection range 11 is shifted in the y direction, which is the same as Fig. 11. In the state of the upper part of Fig. 12, the air-equivalent length of the optical path from the second mirror 152 to the projection optical system 23 is C+D+E.

[0105] The lower part of Fig. 12 shows a state after the projection range 11 has been shifted in the direction y. In the example of Fig. 12, the control device 4 controls the third mirror 153 and the fourth mirror 154 to be displaced in the direction x1, and the fourth mirror 154 to be displaced in the direction y1. This allows the image G1 (projection range 11) to be shifted in the direction y1.

[0106] Specifically, the control device 4 performs control to displace the third mirror 153 and the fourth mirror 154 by Δ in the direction x1, and to displace the fourth mirror 154 by 2Δ in the direction y1. As a result, compared to the state of Fig. 11, the air-equivalent length of the optical path from the second mirror 152 to the third mirror 153 is reduced by Δ, the air-equivalent length of the optical path from the third mirror 153 to the fourth mirror 154 is increased by 2Δ, and the air-equivalent length of the optical path from the fourth mirror 54 to the projection optical system 23 is reduced by Δ.

[0107] 12, the air-equivalent length of the optical path from the second mirror 152 to the projection optical system 23 is (C-Δ)+(D+2Δ)+(E-Δ)=C+D+E, which is the same as the state in the upper part of FIG. 12 (the state in FIG. 11). Therefore, as in the other configuration examples, even if the image G1 is shifted in the direction y, the air-equivalent length of the optical path between the dichroic prism 22a and the projection optical system 23 can be maintained. This makes it possible to suppress unintended blurring of the image G1 caused by a change in the imaging position of the image G1 in the direction x, and to shift the projection range 11 while suppressing a decrease in projection quality.

[0108] <Shifting of the projection range 11 in the direction z by the second shift mechanism 50 shown in FIG. 11> Fig. 13 is a diagram showing an example of the shift of the projection range 11 in the direction z by the second shift mechanism 50 shown in Fig. 11. Fig. 13 shows the second mirror 152, the third mirror 153, the fourth mirror 154, and the projection optical system 23 before and after the shift of the projection range 11 in the direction z, as viewed from the direction y1 toward the direction y2.

[0109] The upper part of Fig. 13 shows the state before the projection range 11 is shifted in the direction z, which is the same as Fig. 11. In the state of the upper part of Fig. 13, the air-equivalent length of the optical path from the dichroic prism 22a to the third mirror 153 is A+B+C.

[0110] The lower part of Fig. 13 shows a state after the projection range 11 has been shifted in the direction z. In the example of Fig. 13, the control device 4 controls the first mirror 151 and the second mirror 152 to be displaced in the direction x1, and the second mirror 152 and the third mirror 153 to be displaced in the direction z1. This allows the image G1 (projection range 11) to be shifted in the direction z1.

[0111] Specifically, the control device 4 performs control to displace the first mirror 151 and the second mirror 152 by Δ in the direction x1, and to displace the second mirror 152 and the third mirror 153 by 2Δ in the direction z1. As a result, compared to the state of Fig. 11, the air-equivalent length of the optical path from the dichroic prism 22a to the first mirror 151 is reduced by Δ, the air-equivalent length of the optical path from the first mirror 151 to the second mirror 152 is increased by 2Δ, and the air-equivalent length of the optical path from the second mirror 152 to the third mirror 153 is reduced by Δ.

[0112] 13, the air-equivalent length of the optical path from the dichroic prism 22a to the third mirror 153 is (A-Δ)+(B+2Δ)+(C-Δ)=A+B+C, which is the same as the upper state of FIG. 13 (the state of FIG. 11). Therefore, as with the other configuration examples, even if the projection range 11 is shifted in the direction z, the air-equivalent length of the optical path between the dichroic prism 22a and the projection optical system 23 can be maintained. This makes it possible to suppress unintended blurring of the image G1 caused by a change in the imaging position of the image G1 in the direction x, and to shift the projection range 11 while suppressing a decrease in projection quality.

[0113] 12 and 13, the second shift mechanism 50 shown in Fig. 11 can shift the projection range 11 in the direction y or the direction z. The control device 4 may also shift the projection range 11 in both the direction y and the direction z by combining the controls shown in Figs. 12 and 13.

[0114] <Another example of shifting the projection range 11 in the direction y by the second shift mechanism 50 shown in FIG. 11> Fig. 14 is a diagram showing another example of the shift of the projection range 11 in the direction y by the second shift mechanism 50 shown in Fig. 11. In Fig. 12 above, when the air-equivalent length of the optical path from the third mirror 153 to the fourth mirror 154 is lengthened to shift the projection range 11 in the direction y, the air-equivalent length of the optical path from the second mirror 152 to the third mirror 153 and the air-equivalent length of the optical path from the fourth mirror 154 to the projection optical system 23 are shortened to maintain the overall air-equivalent length, but the control for maintaining the overall air-equivalent length is not limited to this.

[0115] In Figure 14, the optical path from the dichroic prism 22a to the first mirror 151, the optical path from the first mirror 151 to the second mirror 152, the optical path from the second mirror 152 to the third mirror 153, and the optical path from the third mirror 153 to the projection optical system 23 are shown on a plane before and after a shift in the direction y of the projection range 11.

[0116] The upper part of Fig. 14 shows the state before the projection range 11 is shifted in the y direction, which is the same as Fig. 11. In the state of the upper part of Fig. 14, the air-equivalent length of the optical path from the dichroic prism 22a to the projection optical system 23 is A+B+C+D+E.

[0117] The lower part of Fig. 14 shows the state after the projection range 11 is shifted in the direction y. In the example of Fig. 14, the control device 4 performs control to displace the fourth mirror 154 by 4Δ in the direction y1, displace the third mirror 153 and the fourth mirror 154 by Δ in the direction x1, and displace the first mirror 151 and the second mirror 152 by Δ in the direction x2. This allows the image G1 (projection range 11) to be shifted by 4Δ in the direction y1.

[0118] In the state shown in the lower part of Fig. 14, the air-equivalent length of the optical path from the dichroic prism 22a to the projection optical system 23 is (A-Δ)+B+(C-2Δ)+(D+4Δ)+(E-Δ)=A+B+C+D+E, which is the same as the state shown in the upper part of Fig. 14. Therefore, as in the other configuration examples, even if the image G1 is shifted in the direction y, the air-equivalent length of the optical path between the dichroic prism 22a and the projection optical system 23 can be maintained. This makes it possible to suppress unintended blurring of the image G1 caused by a change in the imaging position of the image G1 in the direction x, and to shift the projection range 11 while suppressing a decrease in projection quality.

[0119] As shown in FIG. 14, when shifting the projection range 11 in the direction y, the displacement of each mirror can be reduced by displacing not only the third mirror 153 and the fourth mirror 154 but also the first mirror 151 and the second mirror 152 to maintain the air-equivalent length of the optical path.

[0120] <Another example of shifting the projection range 11 in the direction z by the second shift mechanism 50 shown in FIG. 11> Fig. 15 is a diagram showing another example of the shift of the projection range 11 in the direction z by the second shift mechanism 50 shown in Fig. 11. In Fig. 13, for example, when the air-equivalent length of the optical path from the first mirror 151 to the second mirror 152 is lengthened to shift the projection range 11 in the direction z, the air-equivalent length of the optical path from the dichroic prism 22a to the first mirror 151 and the air-equivalent length of the optical path from the second mirror 152 to the third mirror 153 are shortened to maintain the overall air-equivalent length, but the control for maintaining the overall air-equivalent length is not limited to this.

[0121] In Figure 15, the optical path from the dichroic prism 22a to the first mirror 151, the optical path from the first mirror 151 to the second mirror 152, the optical path from the second mirror 152 to the third mirror 153, and the optical path from the third mirror 153 to the projection optical system 23 are shown on a plane before and after a shift in the direction z of the projection range 11.

[0122] The upper part of Fig. 15 shows the state before the projection range 11 is shifted in the direction z, which is the same as Fig. 11. In the state of the upper part of Fig. 15, the air-equivalent length of the optical path from the dichroic prism 22a to the projection optical system 23 is A+B+C+D+E.

[0123] The lower part of Fig. 15 shows the state after the projection range 11 is shifted in the direction z. In the example of Fig. 15, the control device 4 performs control to displace the second mirror 152, the third mirror 153, and the fourth mirror 154 by 4Δ in the direction z1, to displace the third mirror 153 and the fourth mirror 154 by 4Δ in the direction z1, to displace the first mirror 151 and the second mirror 152 by Δ in the direction x2, and to displace the third mirror 153 and the fourth mirror 154 by Δ in the direction x1. This allows the image G1 (projection range 11) to be shifted by 4Δ in the direction z1.

[0124] In the state shown in the lower part of Fig. 15, the air-equivalent length of the optical path from the dichroic prism 22a to the projection optical system 23 is (A-Δ)+(B+4Δ)+(C-2Δ)+D+(E-Δ)=A+B+C+D+E, which is the same as the state shown in the upper part of Fig. 15. Therefore, as in the other configuration examples, even if the projection range 11 is shifted in the direction z, the air-equivalent length of the optical path between the dichroic prism 22a and the projection optical system 23 can be maintained. This makes it possible to suppress unintended blurring of the image G1 caused by a change in the imaging position of the image G1 in the direction x, and to shift the projection range 11 while suppressing a decrease in projection quality.

[0125] As shown in FIG. 15, when shifting the projection range 11 in the direction z, the displacement of each mirror can be reduced by displacing not only the first mirror 151, the second mirror 152, and the third mirror 153 but also the fourth mirror 154 to maintain the air-equivalent length of the optical path.

[0126] <Combination of controls by the control device 4> 12 and 13 is performed by displacing a relatively small number of reflecting parts by a relatively large amount, so the amount of displacement of the reflecting parts relative to the amount of shift of the projection range 11 is large, making it possible to shift the projection range 11 with high precision. On the other hand, the control shown in Figs. 14 and 15 is performed by displacing a relatively large number of reflecting parts by a relatively small amount, so it is possible to shift the projection range 11 at high speed.

[0127] For this reason, the control device 4 may first shift the projection range 11 at high speed using the control shown in Figures 14 and 15 as a coarse adjustment, and then shift the projection range 11 with high precision using the control shown in Figures 12 and 13 as a fine adjustment.

[0128] <Design of the second shift mechanism 50> If the shiftable width of image G1 in direction y is defined as V shift width, and the shiftable width of image G1 in direction z is defined as H shift width, the second shift mechanism 50 shown in Figures 12 and 13 is designed to satisfy, for example, the following equation (1).

[0129] Amax ≧ V shift width / 2 Bmax ≧ V shift width Cmax ≧ (V shift width + H shift width) / 2 Dmax ≧ H shift width Emax ≧ H shift width / 2 (1)

[0130] Further, the second shift mechanism 50 shown in FIGS. 14 and 15 is designed to satisfy, for example, the following formula (2).

[0131] Amax ≧ (V shift width + H shift width) / 3 Bmax ≧ V shift width Cmax ≧ (V shift width + H shift width) / 3 Dmax ≧ H shift width Emax ≧ (V shift width + H shift width) / 3 (2)

[0132] In equations (1) and (2), Amax is the maximum distance between the dichroic prism 22a and the first mirror 151, Bmax is the maximum distance between the first mirror 151 and the second mirror 152, Cmax is the maximum distance between the second mirror 152 and the third mirror 153, Dmax is the maximum distance between the third mirror 153 and the fourth mirror 154, and Emax is the maximum distance between the fourth mirror 154 and the projection optical system 23.

[0133] <Configuration Example 5 of Second Shift Mechanism 50> Fig. 16 is a diagram showing a fifth configuration example of the second shift mechanism 50. In Figs. 11 to 15, a configuration has been described in which the second shift mechanism 50 includes the first mirror 151, the second mirror 152, the third mirror 153, and the fourth mirror 154 as a configuration capable of shifting the projection range 11 in the directions y and z, but the configuration is not limited to this.

[0134] 16, the second shift mechanism 50 may include a fifth mirror 155 in addition to the first mirror 151, the second mirror 152, the third mirror 153, and the fourth mirror 154. The fourth mirror 154 reflects the light emitted from the third mirror 153 in the direction y1 and emits it in the direction z1. The fifth mirror 155 reflects the light emitted from the fourth mirror 154 in the direction z1 and emits it in the direction x1. The light emitted from the fifth mirror 155 is projected as an image G1 by the projection optical system 23.

[0135] Although the configuration in which the fifth mirror 155 is provided between the fourth mirror 154 and the projection optical system 23 has been described, the fifth mirror 155 may also be provided between the dichroic prism 22a and the first mirror 151, or between the second mirror 152 and the third mirror 153, or between the third mirror 153 and the fourth mirror 154.

[0136] The above-mentioned configuration examples of the second shift mechanism 50 can also be implemented in combination. For example, in the second shift mechanism 50 shown in Fig. 11, the directions in which some of the reflecting sections can be displaced may be limited as shown in Figs. 7 and 8, or some of the reflecting sections may be separated and fixed in position as shown in Figs. 9 and 10. Furthermore, the control device 4 may control the displacement of each reflecting section while maintaining the air-equivalent length of the optical path from the light modulation section 22 to the projection optical system 23.

[0137] <Dual screen projection by the projection device 10> Fig. 17 is a diagram showing an example of dual-screen projection by the projection device 10. The projection device 10 may be capable of projecting a plurality of images onto the projection object 6. Projection ranges 11a and 11b shown in Fig. 17 are two areas of the projection object 6 onto which projection light is irradiated by the projection unit 1. In the example of Fig. 17, the same image (the character string "ABC") is projected onto the projection ranges 11a and 11b.

[0138] In the example of FIG. 17, both projection ranges 11a and 11b are projection ranges on projection object 6, but projection ranges 11a and 11b may be projection ranges on different projection objects.

[0139] <Configuration of the projection device 10 for dual screen projection> Fig. 18 is a diagram showing an example of the configuration of a projection device 10 that performs dual screen projection. Fig. 19 is a diagram showing an example of shifting of the projection range 11 by the second shift mechanism 50 shown in Fig. 18.

[0140] The projection device 10 shown in Figures 18 and 19 includes a half mirror 51a instead of the first mirror 51 shown in Figure 5. The half mirror 51a is an example of a branching member that branches the optical image modulated by the light modulation unit 22 (light modulation element). The half mirror 51a reflects a part of the light emitted from the dichroic prism 22a in the direction x1 and emits it in the direction y1 (second mirror 52), and transmits the remainder of the light emitted from the dichroic prism 22a in the direction x1 and emits it in the direction x1.

[0141] An image G1 is an image projected onto the projection range 11a shown in Fig. 17, and an image G2 is an image projected onto the projection range 11b shown in Fig. 17. Light (first light) emitted from the half mirror 51a in the direction y1 is reflected by the second mirror 52, the third mirror 53, and the fourth mirror 54, and projected as image G1 by the projection optical system 23. On the other hand, light (second light) emitted from the half mirror 51a in the direction x1 is projected as it is by the projection optical system 23 as image G2.

[0142] In this way, the light emitted from the dichroic prism 22a is split by the half mirror 51a, so that the images G1 and G2 can be projected onto the projection ranges 11a and 11b, respectively. Furthermore, by configuring each light split by the half mirror 51a to be projected by the common projection optical system 23, it is possible to prevent the projection device 10 from becoming large, and to easily make the projection quality of the images G1 and G2 uniform, compared to a configuration in which a plurality of projection optical systems 23 are provided to project each light split by the half mirror 51a.

[0143] 19, the image G1 can be displaced in the direction y by the second shift mechanism 50. This makes it possible to adjust the relative positional relationship (for example, the distance) between the images G1 and G2 (projection ranges 11a and 11b).

[0144] Furthermore, the second shift mechanism 50 can suppress a change in the imaging position of the image G1 in the direction x even if the image G1 is displaced in the direction y, so that unintended variations in the projection quality of the images G1 and G2 (e.g., variations in focus) can be suppressed. Therefore, the relative positional relationship between the images G1 and G2 can be adjusted while suppressing a decrease in the projection quality.

[0145] <Another Example of the Configuration of the Projection Device 10 Performing Dual Screen Projection> Fig. 20 is a diagram showing another example of the configuration of the projection device 10 performing dual-screen projection. The projection device 10 shown in Figs. 18 and 19 may further be provided with an optical member 60. The optical member 60 is a member that transmits light and has a refractive index greater than 1, and an example of the optical member 60 is a glass member. In the example of Fig. 20, the optical member 60 is provided in the optical path from the fourth mirror 54 to the projection optical system 23.

[0146] Here, the path of the first light (light reflected by the half mirror 51a) between the half mirror 51a and the projection optical system 23 is longer than the path of the second light (light passing through the half mirror 51a) between the half mirror 51a and the projection optical system 23 because it passes through the second mirror 52, the third mirror 53, and the fourth mirror 54.

[0147] On the other hand, the air-equivalent length of the first light path can be shortened by providing the optical member 60 on the path of the first light between the half mirror 51a and the projection optical system 23. The refractive index and thickness (length in the light passing direction) of the optical member 60 are designed so that the air-equivalent length of the first light path and the air-equivalent length of the second light path are approximately equal.

[0148] This allows each light branched by the half mirror 51a to be projected by a common projection optical system 23, while the air-equivalent length of each path that each branched light takes to reach the projection optical system 23 can be matched, thereby suppressing unintended variations in the projection quality of images G1, G2 (e.g., focus variations) caused by different path lengths.

[0149] <Another example of dual screen projection by the projection device 10> Fig. 21 is a diagram showing another example of dual-screen projection by the projection device 10. As shown in Fig. 21, the projection device 10 may be configured to be able to project different images onto the projection ranges 11a and 11b. In the example of Fig. 21, an image including the character string "ABC" is projected onto the projection range 11a, and an image including the character string "DEF" is projected onto the projection range 11b.

[0150] For example, in the configuration of the projection device 10 shown in Figs. 18 to 20, the half mirror 51a is a half mirror whose transmittance is variable by an applied voltage or the like. The control device 4 controls the half mirror 51a to switch between a first state (transmittance is approximately 0%) in which the half mirror 51a reflects light without transmitting it, and a second state (transmittance is approximately 100%) in which the half mirror 51a transmits light. At the same time, the control device 4 controls the optical image to be projected onto the projection range 11a to be output from the light modulation unit 22 in the first state, and the optical image to be projected onto the projection range 11a to be output from the light modulation unit 22 in the second state. This allows projection onto the projection range 11a and projection onto the projection range 11b to be performed in a time-division manner, and different images can be projected onto the projection ranges 11a and 11b, respectively.

[0151] However, the configuration capable of projecting different images onto the projection ranges 11a and 11b is not limited to this. For example, a configuration may be adopted in which a first mirror 51 capable of switching the position and angle is provided instead of the half mirror 51a. Then, the control device 4 performs control to switch between a first state in which the first mirror 51 reflects light and a second state in which the first mirror 51 does not reflect light at high speed. At the same time, the control device 4 performs control to output an optical image to be projected onto the projection range 11a from the light modulation unit 22 in the first state, and output an optical image to be projected onto the projection range 11a from the light modulation unit 22 in the second state. This allows projection onto the projection range 11a and projection onto the projection range 11b to be performed in a time-division manner, and different images can be projected onto the projection ranges 11a and 11b.

[0152] Also, instead of the half mirror 51a, a polarizing member may be provided that reflects the first polarized light and outputs it in the direction y1, and transmits the second polarized light different from the first polarized light and outputs it in the direction x1. The light modulation unit 22 is configured to be able to switch between an optical image of the first polarized light and an optical image of the second polarized light and output them. The control device 4 controls the light modulation unit 22 to switch at high speed between a state in which the optical image of the first polarized light to be projected onto the projection range 11a is output from the light modulation unit 22 and a state in which the optical image of the second polarized light to be projected onto the projection range 11b is output from the light modulation unit 22. This allows the projection onto the projection range 11a and the projection onto the projection range 11b to be performed in a time-division manner, and different images can be projected onto the projection ranges 11a and 11b, respectively.

[0153] 18 to 20, an example has been described in which configuration example 1 of the second shift mechanism 50 shown in FIGS. 5 and 6 is configured to be capable of dual screen projection, but other configuration examples of the second shift mechanism 50 may also be configured to be capable of dual screen projection.

[0154] <Variation 1> Although the configuration including the first shift mechanism 105 and the second shift mechanism 50 as the shift mechanism has been described, the projection device 10 may be configured to omit the first shift mechanism 105. In this case as well, the projection range 11 can be shifted by the second shift mechanism 50.

[0155] <Variation 2> Although the configuration in which the second shift mechanism 50 is provided at a position between the light modulation unit 22 and the opening 15a in the main body 101 has been described, the position at which the second shift mechanism 50 is provided is not limited thereto. For example, in the configuration of the projection device 10 shown in FIG. 4, the second shift mechanism 50 may be provided at a position between the opening 2a in the first member 102 and the first optical system 121.

[0156] <Modification 3> In Figures 3 and 4, the configuration of the projection device 10 has been described as a configuration in which the optical axis K is bent twice using the reflecting member 122 and the reflecting member 32. However, it is also possible to omit the reflecting member 122 and the reflecting member 32 and have a configuration in which the optical axis K is not bent, or to omit either the reflecting member 122 or the reflecting member 32 and have a configuration in which the optical axis K is bent once.

[0157] Fig. 22 is a schematic diagram showing another external configuration of the projection device 10. Fig. 23 is a schematic cross-sectional view of the optical unit 106 of the projection device 10 shown in Fig. 22. In Figs. 22 and 23, the same parts as those shown in Figs. 3 and 4 are denoted by the same reference numerals and description thereof will be omitted.

[0158] The optical unit 106 shown in Fig. 22 includes a first member 102 supported by a main body 101, and does not include the second member 103 shown in Fig. 3 and Fig. 4. In addition, the optical unit 106 shown in Fig. 22 does not include the reflecting member 122, the second optical system 31, the reflecting member 32, the third optical system 33, and the projection direction changing mechanism 104 shown in Fig. 3 and Fig. 4.

[0159] In the optical unit 106 shown in Fig. 22, the projection optical system 23 shown in Fig. 2 is composed of a first optical system 121 and a lens 34. Fig. 23 shows an optical axis K of the projection optical system 23. The first optical system 121 and the lens 34 are arranged along the optical axis K in this order from the light modulation unit 22 side.

[0160] The first optical system 121 guides light traveling in the direction X1 incident on the first member 102 from the main body 101 to the lens 34. The lens 34 is disposed at the end of the main body 101 on the direction X1 side so as to close the opening 3c formed at this end. The lens 34 projects the light incident from the first optical system 121 onto the projection object 6.

[0161] <Reference> Fig. 24 is a diagram showing, for reference, an example of the configuration of the second shift mechanism 50 that cannot maintain the air-equivalent length when shifting the projection range 11. The second shift mechanism 50 shown in Fig. 24 has a configuration in which the fourth mirror 54 in the second shift mechanism 50 shown in Fig. 5 cannot be displaced.

[0162] Fig. 25 is a diagram showing, for reference, an example of the shift of the projection range 11 by the second shift mechanism 50 shown in Fig. 24. In the example of Fig. 25, the control device 4 performs control to displace the third mirror 53 by Δ in the direction x2. In this case, compared to the state of Fig. 24, the air-equivalent length of the optical path from the second mirror 52 to the third mirror 53 increases by Δ, the air-equivalent length of the optical path from the third mirror 53 to the fourth mirror 54 decreases by Δ, and the air-equivalent length of the optical path from the fourth mirror 54 to the virtual point 55 increases by Δ.

[0163] 25, the air-equivalent length of the optical path from the second mirror 52 to the virtual point 55 is (A+Δ)+(B-Δ)+(A+Δ)=2A+B+Δ, which is different from the state in FIG. 24. Therefore, when the state in FIG. 24 is changed to the state in FIG. 25 and the image G1 is shifted in the direction y, the air-equivalent length of the optical path between the dichroic prism 22a and the projection optical system 23 changes. As a result, the imaging position of the image G1 in the direction x changes, causing unintended defocusing of the image G1 (e.g., blurring).

[0164] In this way, when only one of the multiple reflecting sections (for example, the first mirror 51, the second mirror 52, the third mirror 53, and the fourth mirror 54) arranged between the light modulation section 22 and the projection optical system 23 is configured to be displaceable, the air-equivalent length cannot be maintained when the projection range 11 is shifted unless the other reflecting sections that cannot be displaced are separated and configured to be discontinuous, for example, as in the configuration examples shown in Figures 9 and 10. In contrast, according to each of the configuration examples of the second shift mechanism 50 described above, the air-equivalent length can be maintained when the projection range 11 is shifted.

[0165] This specification describes at least the following:

[0166] (1) An irradiation unit that irradiates light; a light modulation element that modulates the light from the irradiation unit; a plurality of reflecting portions that reflect the optical image modulated by the light modulation element; a projection optical system that projects the optical image reflected by the plurality of reflecting sections onto a projection surface, the plurality of reflecting sections being disposed between the light modulation element and the projection optical system. Projection device.

[0167] (2) A projection device according to (1), Further comprising a processor, the processor performs control to change the position of the projection range of the optical image by displacing at least one of the plurality of reflecting sections; Projection device.

[0168] (3) The projection device according to (2), the processor performs the control so that an air-equivalent length of a path of the optical image between the light modulation element and the projection optical system becomes a specific value. Projection device.

[0169] (4) A projection device according to (2) or (3), a setting unit that sets the position of the projection range, The processor performs the control based on the position set by the setting unit. Projection device.

[0170] (5) A projection device according to any one of (2) to (4), the processor performs the control while maintaining an air-equivalent length of a path of the optical image between the light modulation element and the projection optical system. Projection device.

[0171] (6) A projection device according to (5), The processor performs the control by displacing the plurality of reflecting sections in a coordinated manner. Projection device.

[0172] (7) A projection device according to (5) or (6), The processor performs the control by repeatedly performing a process of displacing the plurality of reflecting portions. Projection device.

[0173] (8) A projection device according to (5) or (6), The processor performs the control by simultaneously displacing the plurality of reflecting portions. Projection device.

[0174] (9) A projection device according to any one of (2) to (8), The plurality of reflecting sections include a first reflecting section for changing the position of the projection range in a first direction, and a second reflecting section for changing the position of the projection range in a second direction different from the first direction. Projection device.

[0175] (10) A projection device according to any one of (1) to (9), a branching member that branches the optical image modulated by the light modulation element, the plurality of reflecting portions reflect a first light of the optical image branched by the branching member; the projection optical system projects the first light reflected by the plurality of reflecting portions onto the projection surface; Projection device.

[0176] (11) The projection device according to (10), the projection optical system projects the first light and a second light of the optical image branched by the branching member, the second light being different from the first light, onto the projection surface; Projection device.

[0177] (12) A projection device according to (11), an optical member provided in a path of the first light, the optical member having a refractive index and a thickness that match an air-equivalent length of the path of the first light between the branching member and the projection optical system and an air-equivalent length of the path of the second light between the branching member and the projection optical system; Projection device.

[0178] (13) A projection device according to any one of (1) to (12), The plurality of reflecting sections each have four or more reflecting surfaces that reflect the optical image. Projection device.

[0179] (14) A projection device according to any one of (1) to (13), Further, a prism is provided, The prism is disposed between the plurality of reflecting portions and the light modulation element. Projection device.

[0180] (15) An irradiation unit that irradiates light; a light modulation element that modulates the light from the irradiation unit; a plurality of reflecting portions that reflect the optical image modulated by the light modulation element; a projection optical system that projects the optical images reflected by the plurality of reflecting portions onto a projection surface; A control method for a projection device comprising: the plurality of reflecting units are disposed between the light modulation element and the projection optical system, the processor performs control to change the position of the projection range of the optical image by displacing at least one of the plurality of reflecting sections; Control methods.

[0181] (16) The control method according to (15), the processor performs the control so that an air-equivalent length of a path of the optical image between the light modulation element and the projection optical system becomes a specific value. Control methods.

[0182] (17) The control method according to (15) or (16), a setting unit that sets the position of the projection range, The processor performs the control based on the position set by the setting unit. Control methods.

[0183] (18) The control method according to any one of (15) to (17), the processor performs the control while maintaining an air-equivalent length of a path of the optical image between the light modulation element and the projection optical system. Control methods.

[0184] (19) The control method according to (18), The processor performs the control by displacing the plurality of reflecting sections in a coordinated manner. Control methods.

[0185] (20) The control method according to (18) or (19), The processor performs the control by repeatedly performing a process of displacing the plurality of reflecting portions. Control methods.

[0186] (twenty one) The control method according to (18) or (19), The processor performs the control to simultaneously displace the plurality of reflecting portions. Control methods.

[0187] (twenty two) The control method according to any one of (15) to (21), The plurality of reflecting sections include a first reflecting section for changing the position of the projection range in a first direction, and a second reflecting section for changing the position of the projection range in a second direction different from the first direction. Control methods.

[0188] (twenty three) The control method according to any one of (15) to (22), a branching member that branches the optical image modulated by the light modulation element, the plurality of reflecting portions reflect a first light of the optical image branched by the branching member; the projection optical system projects the first light reflected by the plurality of reflecting portions onto the projection surface; Control methods.

[0189] (twenty four) The control method according to (23), the projection optical system projects the first light and a second light of the optical image branched by the branching member, the second light being different from the first light, onto the projection surface; Control methods.

[0190] (twenty five) The control method according to (24), an optical member provided in a path of the first light, the optical member having a refractive index and a thickness that match an air-equivalent length of the path of the first light between the branching member and the projection optical system and an air-equivalent length of the path of the second light between the branching member and the projection optical system; Control methods.

[0191] (26) The control method according to any one of (15) to (25), The plurality of reflecting sections each have four or more reflecting surfaces that reflect the optical image. Control methods.

[0192] (27) The control method according to any one of (15) to (26), Further, a prism is provided, The prism is disposed between the plurality of reflecting portions and the light modulation element. Control methods. [Explanation of symbols]

[0193] 1 Projection section 2 Operation reception section 2A,3A Hollow part 2a,2b,3a,3c,15a opening 4. Control device 4a Storage medium 6. Projection Object 10 Projection device 11,11a,11b Projection range 12 Optical Modulation Unit 15. Cabinet 21 Light source 22 Optical modulation section 22a Dichroic Prism 23 Projection optical system 24 Control circuit 31 Second optical system 32,122 Reflective material 33 Third optical system 34 Lens 50 Second shift mechanism 51,151 1st mirror 51a Half mirror 52,152 2nd mirror 53,153 3rd mirror 54, 54a, 54b, 154 4th mirror 55 Virtual points 60 Optical Components 101 Main body 102 First member 103 Second member 104 Projection direction change mechanism 105 First shift mechanism 106 Optical Unit 121 1st optical system 155 5th Mirror G1, G2 images

Claims

1. An irradiation unit that irradiates light; a light modulation element that modulates the light from the irradiation unit; a plurality of reflecting portions that reflect the optical image modulated by the light modulation element; a projection optical system that projects the optical images reflected by the plurality of reflecting portions onto a projection surface; a processor; the plurality of reflecting units are disposed between the light modulation element and the projection optical system, the processor performs control to change a position of a projection range of the optical image by displacing at least one of the plurality of reflecting units while maintaining an air-equivalent length of a path of the optical image between the light modulation element and the projection optical system. Projection device.

2. A projection device as claimed in claim 1, the processor performs the control so that an air-equivalent length of a path of the optical image between the light modulation element and the projection optical system becomes a specific value. Projection device.

3. A projection device according to claim 1 or 2, a setting unit that sets the position of the projection range, The processor performs the control based on the position set by the setting unit. Projection device.

4. A projection device according to any one of claims 1 to 3, The processor performs the control by displacing the plurality of reflecting portions in a coordinated manner. Projection device.

5. A projection device according to any one of claims 1 to 4, The processor performs the control by repeatedly performing a process of displacing the plurality of reflecting portions. Projection device.

6. A projection device according to any one of claims 1 to 4, The processor performs the control by simultaneously displacing the plurality of reflecting portions. Projection device.

7. A projection device according to any one of claims 1 to 6, a branching member that branches the optical image modulated by the light modulation element, the plurality of reflecting portions reflect a first light of the optical image branched by the branching member; the projection optical system projects the first light reflected by the plurality of reflecting portions onto the projection surface; Projection device.

8. A projection device as claimed in claim 7, the projection optical system projects the first light and a second light, which is different from the first light, of the optical image branched by the branching member onto the projection surface; Projection device.

9. A projection device according to any one of claims 1 to 8, The plurality of reflecting portions each have four or more reflecting surfaces that reflect the optical image. Projection device.

10. A projection device according to any one of claims 1 to 9, Further, a prism is provided, The prism is disposed between the plurality of reflecting portions and the light modulation element. Projection device.

11. An irradiation unit that irradiates light; a light modulation element that modulates the light from the irradiation unit; a plurality of reflecting portions that reflect the optical image modulated by the light modulation element; a projection optical system that projects the optical images reflected by the plurality of reflecting portions onto a projection surface; A control method for a projection device comprising: the plurality of reflecting units are disposed between the light modulation element and the projection optical system, the processor performs control to change the position of the projection range of the optical image by displacing at least one of the plurality of reflecting units while maintaining the air-equivalent length of the path of the optical image between the light modulation element and the projection optical system. Control methods.

12. The control method according to claim 11, the processor performs the control so that an air-equivalent length of a path of the optical image between the light modulation element and the projection optical system becomes a specific value. Control methods.

13. The control method according to claim 11 or 12, a setting unit that sets the position of the projection range, The processor performs the control based on the position set by the setting unit. Control methods.

14. A control method according to any one of claims 11 to 13, comprising: The processor performs the control by displacing the plurality of reflecting portions in a coordinated manner. Control methods.

15. A control method according to any one of claims 11 to 14, comprising: The processor performs the control by repeatedly performing a process of displacing the plurality of reflecting portions. Control methods.

16. A control method according to any one of claims 11 to 14, comprising: The processor performs the control to simultaneously displace the plurality of reflecting portions. Control methods.

17. A control method according to any one of claims 11 to 16, comprising: a branching member that branches the optical image modulated by the light modulation element, the plurality of reflecting portions reflect a first light of the optical image branched by the branching member; the projection optical system projects the first light reflected by the plurality of reflecting portions onto the projection surface; Control methods.

18. The control method according to claim 17, the projection optical system projects the first light and a second light, which is different from the first light, of the optical image branched by the branching member onto the projection surface; Control methods.

19. A control method according to any one of claims 11 to 18, comprising: The plurality of reflecting portions each have four or more reflecting surfaces that reflect the optical image. Control methods.

20. A control method according to any one of claims 11 to 19, comprising: Further, a prism is provided, The prism is disposed between the plurality of reflecting portions and the light modulation element. Control methods.

21. An irradiation unit that irradiates light, a light modulation element that modulates the light from the irradiation unit; a plurality of reflecting portions that reflect the optical image modulated by the light modulation element; a projection optical system that projects the optical images reflected by the plurality of reflecting portions onto a projection surface; a processor; the processor performs control to change a position of a projection range of the optical image by displacing at least one of the plurality of reflecting portions; the plurality of reflecting units are disposed between the light modulation element and the projection optical system, and include a first reflecting unit for changing the position of the projection range in a first direction, and a second reflecting unit for changing the position of the projection range in a second direction different from the first direction; Projection device.

22. An irradiation unit that irradiates light, a light modulation element that modulates the light from the irradiation unit; a plurality of reflecting portions that reflect the optical image modulated by the light modulation element; a projection optical system that projects the optical images reflected by the plurality of reflecting portions onto a projection surface; A control method for a projection device comprising: the processor performs control to change the position of the projection range of the optical image by displacing at least one of the plurality of reflecting portions; the plurality of reflecting units are disposed between the light modulation element and the projection optical system, and include a first reflecting unit for changing the position of the projection range in a first direction, and a second reflecting unit for changing the position of the projection range in a second direction different from the first direction; Control methods.

23. An irradiation unit that irradiates light, a light modulation element that modulates the light from the irradiation unit; a plurality of reflecting portions that reflect the optical image modulated by the light modulation element; a projection optical system that projects the optical images reflected by the plurality of reflecting portions onto a projection surface; a branching member that branches the optical image modulated by the light modulation element, The plurality of reflecting portions are a light modulator arranged between the light modulator and the projection optical system; reflecting a first light of the optical image branched by the branching member; the projection optical system projects, onto the projection surface, the first light reflected by the plurality of reflecting portions and a second light of the optical image branched by the branching member, the second light being different from the first light; an optical member provided in a path of the first light, the optical member having a refractive index and a thickness that match an air-equivalent length of the path of the first light between the branching member and the projection optical system and an air-equivalent length of the path of the second light between the branching member and the projection optical system; Projection device.

24. An irradiation unit that irradiates light, a light modulation element that modulates the light from the irradiation unit; a plurality of reflecting portions that reflect the optical image modulated by the light modulation element; a projection optical system that projects the optical images reflected by the plurality of reflecting portions onto a projection surface; a branching member that branches the optical image modulated by the light modulation element; A control method for a projection device comprising: The plurality of reflecting portions are a light modulator arranged between the light modulator and the projection optical system; reflecting a first light of the optical image branched by the branching member; the projection optical system projects, onto the projection surface, the first light reflected by the plurality of reflecting portions and a second light of the optical image branched by the branching member, the second light being different from the first light; the processor performs control to change the position of the projection range of the optical image by displacing at least one of the plurality of reflecting portions; the projection device includes an optical member that is provided in a path of the first light, and has a refractive index and a thickness that match an air-equivalent length of the path of the first light between the branching member and the projection optical system and an air-equivalent length of the path of the second light between the branching member and the projection optical system. Control methods.

Images