Projection device, control method, and control program

Abstract

Provided are a projection device, a control method, and a control program that can suppress ghosts during projection.　A projection device (10) comprises a lens (34) and a control device (4). The projection device (10) can shift a projected image G1. The control device (4) acquires information about the installation state of the projection device (10). The control device (4) also performs control that restricts shift of the projected image G1 in accordance with the installation state of the projection device (10). The present invention can thereby suppress ghosts during projection.

Description

Projection device, control method, and control program

[0001] The present invention relates to a projection device, a control method, and a control program.

[0002] Patent document 1 describes a projector that includes a control unit, a lens shift drive unit, and an obstacle detection unit. The obstacle detection unit detects obstacles (people, etc.) within the image projection area using a distance sensor, and when an obstacle is detected, the control unit issues an instruction to the lens shift drive unit to shift the lens to a projection area where there are no obstacles.

[0003] Patent Document 2 describes a projector that includes a CPU (Central Processing Unit), a projection optical system adjustment unit, an acceleration sensor, and a distance sensor, and the projection optical system adjustment unit has an electric zoom function, an electric focus function, and an electric lens shift function, the acceleration sensor detects the amount of change in the position of the projector, the distance sensor measures the distance from the projector to the screen, and the CPU adjusts and controls the electric zoom function, the electric focus function, and the electric lens shift function so that the position, shape, and size of the projected image can be maintained even if the installation position of the projector or the distance from the screen changes.

[0004] Patent document 3 describes a projector that includes a shift allowance plate having an opening similar in shape to the shift allowance range but smaller than the shift allowance range, and a through hole that allows light emitted from the light-emitting unit to pass through; a projection lens that is placed within the opening and displaces in either direction to displace the shift allowance plate; a detector that detects that the projection lens has been displaced to its limit position based on the light reception state of the light-receiving unit; and a controller that stops the displacement of the projection lens when the detector detects that the shift allowance plate has been displaced to its limit position based on the displacement of the projection lens.

[0005] Japanese Patent Publication No. 2014-163954 Japanese Patent Publication No. 2009-075147 Japanese Patent Publication No. 2022-095141

[0006] One embodiment of the technique of the present disclosure provides a projection device, a control method, and a control program that are capable of suppressing ghosts during projection.

[0007] (1) A projection device that includes a projection lens and a processor and is capable of shifting a projected image, wherein the processor acquires information about an installation state of the projection device and performs control to limit the shift of the projected image according to the installation state.

[0008] (2) The projection device according to (1), wherein the installation state is a state regarding a positional relationship between the projection lens and an object on which the projection device is to be installed.

[0009] (3) The projection device according to (1) or (2), wherein the installation state includes an embedded state in which at least a part of the projection device is embedded in an object on which the projection device is to be installed.

[0010] (4) The projection device according to (3), wherein the processor imposes a stronger restriction on the shift in the embedded state than in the installation state different from the embedded state.

[0011] (5) The projection device according to any one of (1) to (4), wherein the information about the installation state includes information about a distance between the projection lens and an object other than the projection device that is closest to the projection lens, and the processor limits the shift depending on the distance.

[0012] (6) The projection device according to any one of (1) to (4), wherein the information about the installation state includes information about a distance between the projection lens and an object on which the projection device is installed, and the processor limits the shift depending on the distance.

[0013] (7) The projection device according to any one of (1) to (6), wherein the processor limits the shift in a direction according to a positional relationship between the projection lens and an object on which the projection device is installed.

[0014] (8) The projection device according to any one of (1) to (7), wherein the processor performs control to limit the shift depending on the installation state and a state of a light source of the projection device.

[0015] (9) The projection device according to (8), wherein the state of the light source includes a state of an output value of the light source.

[0016] (10) The projection device according to (9), wherein the processor imposes a stronger restriction on the shift when the output value is a first output value than when the output value is a second output value that is lower than the first output value.

[0017] (11) The projection device according to any one of (1) to (6), wherein the processor controls an output value of a light source of the projection device based on a state of the shift.

[0018] (12) The projection device according to any one of (1) to (11), wherein the processor controls to limit the shift depending on the installation state and the image content of the projected image.

[0019] (13) The projection device according to (12), wherein the processor performs control to limit the shift depending on the installation state and brightness of the image content of the projected image.

[0020] (14) The projection device according to (13), wherein the processor limits the shift in a direction according to brightness of a plurality of edge regions in the image content of the projected image.

[0021] (15) The projection device according to any one of (1) to (14), wherein the processor maintains the state of the shift when information relating to the limit of the shift changes during projection of the projection image.

[0022] (16) The projection device according to (15), wherein, when a user operation relating to the shift is performed while the shift state is maintained, the processor changes the state of the shift in accordance with information relating to restrictions on the shift.

[0023] (17) The projection device according to any one of (1) to (16), wherein the shift is a shift in a direction perpendicular to the optical axis direction of the projection lens.

[0024] (18) A control method for a projection device that includes a projection lens and a processor and is capable of shifting a projected image, the control method comprising: the processor acquiring information about an installation state of the projection device; and performing control to limit the shift of the projected image according to the installation state.

[0025] (19) A control program for a projection device that includes a projection lens and a processor and is capable of shifting a projected image, the control program causing the processor to execute a process of acquiring information about an installation state of the projection device and performing control to limit the shift of the projected image according to the installation state.

[0026] According to the present invention, it is possible to provide a projection device, a control method, and a control program that are capable of suppressing ghosts during projection.

[0027] 7 is a schematic diagram showing an example of a projection device 10 that is a target for installation support by the information processing apparatus of the embodiment. FIG. 7 is a schematic diagram showing an example of the internal configuration of the projection unit 1 shown in FIG. 1. FIG. 7 is a schematic diagram showing the external configuration of the projection device 10. FIG. 8 is a schematic cross-sectional view of the optical unit 106 of the projection device 10 shown in FIG. 3. FIG. 9 is a diagram showing an example of an installation state of the projection device 10. FIG. 10 is a diagram showing another example of an installation state of the projection device 10. FIG. 11 is a diagram showing an example of an installation state in which the projection device 10 is embedded in a ceiling. FIG. 12 is a diagram showing a state in which the position of the projection image G1 is shifted in the projection device 10 shown in FIG. 13. FIG. 14 is a diagram for explaining an example of shift restriction of the projection image G1. FIG. 15 is a flowchart showing a first processing example of shift restriction of the projection device 10. FIG. 16 is a diagram showing an example of a shift restriction table in the first processing example. FIG. 17 is a flowchart showing a second processing example of shift restriction of the projection device 10. FIG. 18 is a diagram showing an example of a black band region in the projection image G1. FIG. 19 is a diagram showing an example of a shift restriction table in the second processing example. FIG. 19 is a flowchart showing a first processing example of output value restriction of the light source 21 with respect to the shift position of the projection image G1. FIG. 19 is a diagram showing an example of an output value restriction table in the first processing example. 1. A flowchart showing a second processing example of limiting the output value of the light source 21 with respect to the shift position of the projection image G1. A diagram showing an example of an output value limit table in the second processing example. A flowchart showing a first modified example of shift limiting of the projection device 10. A diagram showing an example of a shift limit table in the first modified example. A diagram showing a modified example of the configuration of the projection device 10. A diagram showing an example of the hardware configuration of a personal computer 200.

[0028] Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

[0029] <Projection Device 10 of Embodiment> Fig. 1 is a schematic diagram showing an example of a projection device 10 of an embodiment. As shown in Fig. 1, 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 description, the projection unit 1 is assumed to be a liquid crystal projector. The projection unit 1 projects a projection image toward a projection target 6.

[0030] The control device 4 is a control device that controls projection by the projection device 10. The control device 4 is a device that includes a control unit configured with various processors, a communication interface (not shown) for communicating with each unit, and a memory 4a such as a hard disk, an SSD (Solid State Drive), or a ROM (Read Only Memory), and controls the projection unit 1 in an integrated manner.

[0031] The various processors in the control unit of the control device 4 include a CPU (Central Processing Unit), which is a general-purpose processor that executes programs to perform 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 electrical circuit, such as an ASIC (Application Specific Integrated Circuit), which is a processor having a circuit configuration designed specifically to perform specific processing.

[0032] 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 configured with one of the various processors, or may be configured with 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). The control device 4 is an example of a "processor" in the present invention.

[0033] The operation reception unit 2 detects instructions from the user by receiving various operations from the user. The operation reception unit 2 may be a button, key, joystick, etc. provided on the control device 4, or may be a receiving unit, etc. that receives a control signal from a remote controller that remotely controls the control device 4.

[0034] The projection target 6 is an object such as a screen or a wall that has a projection surface on which a projected image is displayed by the projection unit 1. In the example shown in Fig. 1, the projection target 6 has a rectangular flat projection surface. The top, bottom, left, and right of the projection target 6 in Fig. 1 are assumed to be the top, bottom, left, and right of the actual projection target 6.

[0035] A projection range 11, shown by a dashed line, is an area of ​​the 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 all of the projectable range onto which projection by the projection unit 1 can be performed.

[0036] The projection unit 1, the control device 4, and the operation reception unit 2 may be realized by, for example, a single device (see, for example, FIGS. 3 and 4), or the projection unit 1, the control device 4, and the operation reception unit 2 may be separate devices that communicate with each other and cooperate with each other.

[0037] <Internal Configuration of 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.

[0038] As shown in FIG. 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.

[0039] 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.

[0040] The light modulation unit 22 is composed of three liquid crystal panels that modulate the color light emitted from the light source 21 and separated into three colors, red, blue, and green, by a color separation mechanism (not shown), based on image information, and emit each color image. These three liquid crystal panels may be equipped with red, blue, and green filters, respectively, and the white light emitted from the light source 21 may be modulated by each liquid crystal panel to emit each color image.

[0041] The projection optical system 23 receives light from the light source 21 and the light modulation unit 22, and is configured by, for example, a relay optical system including at least one lens. The light that passes through the projection optical system 23 is projected onto the object 6 to be projected.

[0042] The area of ​​the object 6 that is irradiated with light that passes through the entire range of the light modulation unit 22 is the projectable range in which projection by the projection unit 1 is possible. Within this projectable range, the area that is irradiated with light that actually passes through from the light modulation unit 22 is the projection range 11. For example, by controlling the size, position, and shape of the area of ​​the light modulation unit 22 through which light passes, the size, position, and shape of the projection range 11 can be changed within the projectable range.

[0043] 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 this display data onto the projection target 6. The display data input to the control circuit 24 is made up of three pieces of data: red display data, blue display data, and green display data.

[0044] The control circuit 24 also changes the projection optical system 23 based on a command input from the control device 4, thereby enlarging or reducing the projection range 11 (see FIG. 1 ) of the projection unit 1. The control device 4 may also change the projection optical system 23 based on a user operation received by the operation receiving unit 2, thereby moving the projection range 11 of the projection unit 1.

[0045] 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 through which projection light incident on the projection optical system 23 passes through the projection optical system 23 appropriately in terms of light intensity drop-off, color separation, peripheral curvature, etc.

[0046] 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.

[0047] The optical system shift mechanism is, for example, a mechanism that moves the projection optical system 23 in a direction perpendicular to the optical axis (see, for example, FIGS. 3 and 4), or a mechanism that moves 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 that moves the projection optical system 23 and the light modulation unit 22 in combination.

[0048] The electronic shift mechanism is a mechanism that shifts the pseudo projection range 11 by changing the range through which light is transmitted in the light modulation section 22 .

[0049] 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).

[0050] The control circuit 24 controls the shift mechanism or the projection direction change mechanism based on a command input from the control device 4 , thereby moving the projection range 11 of the projection unit 1 .

[0051] <Mechanical Configuration of Projection Device 10> Fig. 3 is a schematic diagram showing an example of 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.

[0052] 3, the projection device 10 includes a main body 101 and an optical unit 106 that protrudes 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.

[0053] The optical unit 106 includes a first member 102 supported by the main body 101 and a second member 103 supported by the first member 102 .

[0054] 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, replaceable).

[0055] 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 106.

[0056] As shown in Figure 3, inside the housing 15 of the main body 101, there is provided a light source 21 and a light modulation unit 12 including a light modulation section 22 (see Figure 2) that spatially modulates the light emitted from the light source 21 based on input image data to generate an image.

[0057] 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.

[0058] 4, an image formed by 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 target 6, which is the projection object, so that a projected image G1 becomes visible to an observer. The projected image G1 is an image formed by the projection light irradiated onto the projection range 11. The projected image G1 is an example of a "projected image" in the present invention.

[0059] As shown in Figure 4, the optical unit 106 comprises a first member 102 having a hollow portion 2A connected to the inside of the main body portion 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 shift mechanism 105, and a projection direction change mechanism 104.

[0060] The first member 102 is a member having, for example, a rectangular cross-sectional outer shape, 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 positioned opposite the opening 15a of the main body 101. Light emitted from the light modulation section 22 of the light 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.

[0061] The direction of light incident from the main body 101 into the hollow portion 2A 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 Figure 4, the direction from the front of the page toward the back and the opposite direction are referred to as direction Z. Of direction Z, the direction from the front of the page toward the back is referred to as direction Z1, and the direction from the back of the page toward the front is referred to as direction Z2.

[0062] Furthermore, a direction perpendicular to direction X and direction 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.

[0063] 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 the 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.

[0064] The first optical system 121 includes at least one lens, and guides light traveling in the direction X1 that is incident on the first member 102 from the main body 101 to the reflecting member 122 .

[0065] The reflecting member 122 reflects the light incident from the first optical system 121 in the 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 travels to the hollow portion 3A of the second member 103.

[0066] The second member 103 is a member having a substantially T-shaped cross-sectional outer shape, and has an opening 3a formed in a position facing the opening 2b of the first member 102. Light from the main body 101 that passes 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 outer shapes of the first member 102 and the second member 103 are arbitrary and are not limited to those described above.

[0067] 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 .

[0068] The reflecting member 32 reflects the light incident from the second optical system 31 in the direction X2 and guides the light to the third optical system 33. The reflecting member 32 is formed of, for example, a mirror.

[0069] The third optical system 33 includes at least one lens, and guides the light reflected by the reflecting member 32 to a lens 34 .

[0070] The lens 34 is disposed at the end of the second member 103 on the direction X2 side 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 target 6. The lens 34 is an example of the "projection lens" according to the present invention.

[0071] The projection direction change mechanism 104 is a rotation mechanism that rotatably connects the second member 103 to the first member 102. This projection direction change mechanism 104 allows the second member 103 to rotate freely around a rotation axis (specifically, optical axis K) that extends 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.

[0072] The 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 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 shift mechanism 105 may be one that moves the first member 102 manually, or one that moves the first member 102 electrically.

[0073] Fig. 4 shows a state in which the first member 102 has been moved to the maximum extent in the direction Y1 by the shift mechanism 105. When the first member 102 is moved in the direction Y2 by the 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 projection image G1 projected onto the projection target 6 can be shifted (translated) in the direction Y2.

[0074] The shift mechanism 105 may be a mechanism that moves the light modulation unit 22 in the direction Y, instead of moving the optical unit 106 in the direction Y. Even in this case, the projection image G1 projected onto the projection target 6 can be moved in the direction Y2.

[0075] <Installation State of Projection Device 10> Next, an installation state of the projection device 10 when it is used will be described. Fig. 5 is a diagram showing an example of an installation state of the projection device 10. As shown in Fig. 5, the projection device 10 can be installed in, for example, a non-embedded state in an object 50 on which it is to be installed. The object 50 on which it is to be installed is, for example, a "floor," a "wall," a "ceiling," a "pillar," or a "pedestal." The non-embedded state includes, for example, a state in which a part of the projection device 10 is installed in contact with the object 50 on which it is to be installed, or a state in which the projection device 10 is installed at a distance from the object 50 on which it is to be installed.

[0076] The state in which the projection device 10 is installed with a part of it in contact with the object 50 on which it is to be installed refers to, for example, the state in which the projection device 10 is placed on the floor or a pedestal, or the state in which the projection device 10 is attached to a wall, ceiling, or pillar. The state in which the projection device 10 is installed at a distance from the object 50 on which it is to be installed refers to, for example, the state in which the projection device 10 is suspended from the ceiling via an attachment member at a distance.

[0077] In the installation example shown in Fig. 5, the projection device 10 is shown placed on a "floor," which is the object 50 to be installed. However, the projection device 10 shown in Fig. 5 is a simplified illustration, and is composed of a box-shaped main body 101 and a box-shaped optical unit 106. The projection device 10 is installed with the main body 101 in contact with the floor, and the optical unit 106 is provided on the main body 101. In addition, the optical unit 106 is provided with a lens 34, and is configured so that light is projected from the lens 34 toward the object 6 to be projected.

[0078] When the projection device 10 is installed in this manner, light that properly passes through the lens 34 is irradiated onto the object 6 to be projected, forming a projected image G1, but when some of the light that is irregularly reflected within the lens 34 is output from the lens 34, it is irradiated onto the floor, for example, as shown in FIG. 5 , and appears as a brightly lit area (hereinafter referred to as a ghost 51). The ghost 51 is likely to appear on objects that are located in front of and around the lens 34. The area where the ghost 51 appears and its intensity (brightness) vary depending on the distance between the object and the lens 34, the intensity of the light output from the lens 34, the projection position of the projected image G1 projected from the lens 34, etc.

[0079] Fig. 6 is a diagram showing another example of an installation state of the projection device 10. As shown in Fig. 6, the projection device 10 may be installed, for example, in a state embedded in the object 50 on which the projection device 10 is to be installed. The embedded state includes, for example, a state in which the projection device 10 is installed so that a part of the projection device 10 is embedded in the object 50 on which the projection device 10 is to be installed.

[0080] The state in which a part of the projection device 10 is installed inside the object 50 to be installed means, for example, a state in which a part of the projection device 10 is housed in a specified space formed by a floor, wall, ceiling, pillar, or base.

[0081] 6 shows an example of installation in which the projection device 10 is embedded in a "wall," which is the object 50 to be installed. The projection device 10 is shown as having a box-shaped main body 101 and a box-shaped optical unit 106, and is installed in such a manner that the main body 101 is housed in a housing space 50a formed in the wall, and the optical unit 106 provided on the main body 101 protrudes from the wall.

[0082] Even when the projection device 10 is installed in this manner, light that properly passes through the lens 34 is irradiated onto the object 6 to be projected and forms the projected image G1, but when some of the light that is irregularly reflected within the lens 34 is output from the lens 34, it is irradiated onto the wall, for example, as shown in Figure 6, and appears as a ghost 51. As with the case of Figure 5 above, the ghost 51 is likely to appear on objects located in front of and around the lens 34. Furthermore, the area where the ghost 51 appears and its intensity (brightness) vary depending on the distance between the object and the lens 34, the intensity of the light output from the lens 34, the projection position of the projected image G1 projected from the lens 34, etc.

[0083] <Example of Installation State that Prevents Appearance of Ghost 51> Next, an installation state of the projection device 10 that prevents the appearance of the ghost 51 will be described. Figures 7 and 8 are diagrams showing an example of an installation state in which the projection device 10 is embedded in the ceiling. As shown in Figures 7 and 8, the projection device 10 is installed in a projection room 52 with the main body 101 disposed on the "ceiling," which is the object 50 to be installed, and the optical unit 106 provided on the main body 101 protruding downward from the ceiling.

[0084] 7 and 8, in Fig. 7, the projection image G1 projected from the lens 34 of the projection device 10 is projected onto an upper region of the projection target 6, whereas in Fig. 8, the projection position of the projection image G1 is projected onto a lower region than the projection position shown in Fig. 7. That is, in Fig. 7, the projection position is shift-controlled so that the projection image G1 is projected onto an upper region closer to the "ceiling," which is the object 50 on which the projection device 10 is installed. On the other hand, in Fig. 8, the projection position is shift-controlled so that the projection image G1 is projected onto a lower region closer to the floor 53 of the projection room 52, which is in a direction away from the ceiling.

[0085] When the projection position of the projection image G1 projected from the lens 34 is shifted in this manner, in the case of FIG. 7 where the projection image G1 is projected onto an area above the projection target 6, a ghost 51 appears on the ceiling in front of the lens 34. In contrast, in the case of FIG. 8 where the projection image G1 is projected onto an area below the projection target 6, the ghost 51 does not appear on the ceiling in front of the lens 34 (this disappearance is indicated by the dashed ghost 51 in FIG. 8). Specifically, in FIG. 8, the projection position of the projection image G1 is shifted so that the upper end of the projection image G1 projected onto the projection target 6 is projected below a position 54 at a predetermined height on the projection target 6, thereby preventing the ghost 51 from appearing on the ceiling. However, the amount of shift required for the projection image G1 changes depending on the distance from the lens 34 to the projection target 6.

[0086] 7 and 8, the case where the appearance of the ghost 51 changes depending on the projection position of the projection image G1 projected from the lens 34 has been described, but in addition to this, for example, when it depends on the distance between the lens 34 and the object 50 on which the projection device 10 is installed, the shorter the distance between them, the more likely the ghost 51 will appear, and the farther the distance between them, the less likely the ghost 51 will appear. Also, when it depends on the intensity of the light output from the lens 34, the stronger the output value of the output light, the more likely the ghost 51 will appear, and the weaker the output value of the output light, the less likely the ghost 51 will appear.

[0087] <Shift Restriction to Prevent Appearance of Ghost 51> Next, a shift restriction on the projection image G1 to prevent the ghost 51 from appearing will be described. Fig. 9 is a diagram for explaining an example of the shift restriction on the projection image G1. As shown in Fig. 9, the projection device 10 is installed in a state where it is embedded in a "wall", which is the object 50 on which it is installed. This installation state is the same as the installation state described in Fig. 6.

[0088] When the projection device 10 is installed in this state, ghost 51 appears depending on the projection position of the projection image G1 projected from the lens 34. Ghost 51 appears on the wall in front of and around the lens 34. Ghost 51 appears when the projection position of the projection image G1 is close to the "wall" on which the projection device 10 is installed, becomes weaker (darker) as the projection position becomes farther away, and does not appear if the projection position is further away than a predetermined distance. Therefore, by setting the projection position of the projection image G1 to an appropriate projection position in relation to the "wall" on which the projection device 10 is installed, i.e., by limiting the range in which the projection image G1 can be shifted to a predetermined range, it is possible to suppress the appearance of ghost 51.

[0089] For example, as shown in FIG. 9 , the direction in which a "wall," which is an object 50 on which the projection device 10 is installed, extends is defined as direction X, and the direction perpendicular to the "wall" is defined as direction Y. Directions X and Y are perpendicular to the optical axis K of the lens 34. In the installation state shown in FIG. 9 , the appearance of a ghost 51 on the "wall" can be suppressed by limiting the range in which the projection image G1 can be shifted in direction Y to a predetermined range. Specifically, the shift range of the projection image G1 in the direction of the "wall" on which the projection device 10 is installed, i.e., the shift range of the projection image G1 in the -Y direction in direction Y, is limited. In this example, the appearance of the ghost 51 can be suppressed by limiting the shift so that the bottom edge 55 of the projection image G1 is projected above (in the +Y direction) a shaded area 56.

[0090] In this way, by limiting the shift range in a direction according to the positional relationship between the lens 34 of the projection device 10 and the object 50 on which the projection device 10 is installed, it is possible to suppress the appearance of a ghost 51 on the object 50. For example, if the projection device 10 is installed on the floor below the projection device 10, the downward shift of the projection image G1 projected from the lens 34 is limited. If the projection device 10 is installed on the wall to the right of the projection device 10, the rightward shift of the projection image G1 projected from the lens 34 is limited. If the projection device 10 is installed on the ceiling above the projection device 10, the upward shift of the projection image G1 projected from the lens 34 is limited.

[0091] 9 shows an installation state in which the projection device 10 is embedded in a "wall," which is the object 50 on which the projection device 10 is to be installed; however, as described in FIG. 5 , the installation state may also be a state in which the projection device 10 is placed on a "floor." When the projection device 10 is installed on a "floor," the distance between the lens 34 and the object 50 on which the projection device 10 is to be installed is longer than when the projection device 10 is embedded in a "wall," and the shift range is limited according to that distance. When the distance between the lens 34 and the object 50 on which the projection device 10 is to be installed is long, the limitations on the shift range are relaxed, and the range in which the projection device 10 can be shifted is wider.

[0092] Furthermore, although the above example describes a case where the ghost 51 appears on the object 50 (floor, wall, ceiling, etc.) on which the projection device 10 is installed, the objects on which the ghost 51 appears are not limited to these. For example, if there is another object in front of the lens 34 that is closer to the lens 34 than the object 50 on which the projection device 10 is installed, the ghost 51 may appear on that object. Therefore, in such a case, the shift range of the projected image G1 may be limited depending on the distance between the lens 34 and the object closest to the lens 34. In this way, depending on the installation situation of the projection device 10, the object closest to the lens 34 may be the object 50 on which the projection device 10 is installed, or another object such as a plate placed nearby.

[0093] Next, the process of shift restriction in the projection device 10 will be described.

[0094] 10 is a flowchart showing a first processing example of shift restriction in the projection device 10. The projection device 10 starts executing this processing, for example, when the projection device 10 is started up.

[0095] First, the projection device 10 determines the installation state of the projection device 10 (step S11). As described above, the installation state of the projection device 10 refers to, for example, whether the projection device 10 is installed in a non-embedded state (see FIG. 5 ) or an embedded state (see FIGS. 6 and 7 ) in the object 50 to be installed. The projection device 10 determines the installation state based on, for example, the setting state of an installation mode switch that is set when the projection device 10 is installed. The installation mode switch is set by a mode selection operation by a user. The projection device 10 may also determine the installation state based on sensing data obtained by a camera or a three-dimensional sensor (lidar) mounted on the projection device 10. The projection device 10 may also be equipped with a remote control receiver in each of the main body 101 and the optical unit 106, and determine the installation state based on the reception state of a signal based on an external remote control operation (which remote control receiver receives the signal).

[0096] Next, the projection device 10 determines the state of the output value of the light source 21 (laser diode (LD)) (step S12). The state of the output value of the light source 21 is determined, for example, by determining what percentage of the output value is relative to the maximum output value of the light source 21.

[0097] Next, the projection device 10 refers to a shift limit table for setting the shift range of the projection image G1 based on the installation state of the projection device 10 and the state of the output value of the light source 21 (step S13). The shift limit table is stored in advance in the memory 4a as measured shift limit data. The shift limit table will be described later with reference to FIG. 11.

[0098] Next, the projection device 10 refers to the shift restriction table and determines whether or not there is a shift restriction on the projection position of the projection image G1 projected from the lens 34 (step S14).

[0099] In step S14, if there is no shift limit on the projection position of the projection image G1 (step S14: No), the projection device 10 ends this process. In step S14, if there is a shift limit on the projection position of the projection image G1 (step S14: Yes), the projection device 10 sets a shift limit on the projection position of the projection image G1 projected from the lens 34 (step S15). In this example, the presence or absence and degree of the shift limit on the projection image G1 are set based on the installation state of the projection device 10 and the state of the output value of the light source 21.

[0100] In the first processing example, the processing is started when the projection device 10 is started, but the present invention is not limited to this. For example, the processing may be repeatedly executed when the projection device 10 is started. The processing may also be executed when a change in the installation state of the projection device 10 is detected or when a change in the output value of the light source 21 is detected. Furthermore, the processing may also be executed when an instruction to shift the projection image G1 is received from the user.

[0101] <Example of Shift Limit Table in First Processing Example> Fig. 11 is a diagram showing an example of a shift limit table in the above-described first processing example. As shown in Fig. 11 , the shift limit table 61 shows the shift limit values ​​of the projection device 10 in a non-embedded state and the shift limit values ​​of the projection device 10 in a buried state for a predetermined output value of the light source 21.

[0102] For example, when the output value of the light source 21 is 100%, and the projection device 10 is in the non-embedded state, the limit of the shift range of the projection image G1 is set to −20% of the lower shift limit. On the other hand, when the projection device 10 is in the embedded state, the limit of the shift range of the projection image G1 is set to −15% of the lower shift limit. A negative (−) lower shift limit refers to the shift limit in the −Y direction in the direction Y, as described in FIG. 9 , that is, the shift limit in the direction of the object 50 on which the projection device 10 is installed. The −20% lower shift limit is a ratio to the maximum shift amount (−100%) in the −Y direction, and indicates that a ghost 51 appears when the shift amount in the −Y direction exceeds −20%.

[0103] Similarly, when the output value of the light source 21 is 80%, the limit of the shift range is set to −25% of the lower shift limit when the projection device 10 is in the non-embedded state, and −20% of the lower shift limit when the projection device 10 is in the embedded state. Furthermore, when the output value of the light source 21 is 60%, the limit of the shift range is set to −30% of the lower shift limit when the projection device 10 is in the non-embedded state, and −25% of the lower shift limit when the projection device 10 is in the embedded state. When the output value of the light source 21 is 40%, the limit of the shift range is set to −35% of the lower shift limit when the projection device 10 is in the non-embedded state, and −30% of the lower shift limit when the projection device 10 is in the embedded state. When the output value of the light source 21 is 20%, the limit of the shift range is set to −40% of the lower shift limit when the projection device 10 is in the non-embedded state, and −35% of the lower shift limit when the projection device 10 is in the embedded state.

[0104] As described above, when the output value of the light source 21 is high, ghosts 51 are more likely to appear than when the output value of the light source 21 is low, and therefore a strong (strict) restriction is imposed on the shift range of the projected image G1. Furthermore, when the projection device 10 is installed in a recessed state, the distance between the lens 34 and the object 50 on which the projection device 10 is installed is shorter than when the projection device 10 is not recessed, and therefore ghosts 51 are more likely to appear, and therefore a strong restriction is imposed on the shift range of the projected image G1. Note that a strong restriction on the shift range means that the shiftable area becomes narrower. Furthermore, in this example, because the object 50 on which the projection device 10 is installed is located below the lens 34, a shift limit table 61 that limits the downward shift range of the projected image G1 is stored in the memory 4a. However, if a shift limit in another direction is required, a shift limit table to be used may be prepared and stored in the memory 4a.

[0105] As described above, in the first example of shift restriction processing, the projection device 10 limits the range within which the projection image G1 can be shifted based on information about the installation state of the projection device 10 and information about the output value of the light source 21. With this configuration, the projection image G1 of the projection device 10 can be displayed at a distance greater than a predetermined distance corresponding to the output value of the light source 21 from an object present around the lens 34 of the projection device 10. This makes it possible to suppress ghosts 51 that may appear on objects around the lens 34 of the projection device 10 based on the projection light, such as ghosts 51 that may appear on the object 50 (floor, wall, etc.) on which the projection device 10 is installed.

[0106] 12 is a flowchart showing a second processing example of shift restriction in the projection device 10. As in the first processing example of shift restriction described above, the projection device 10 starts execution of this processing, for example, when the projection device 10 is started up.

[0107] As shown in Fig. 12, in the second processing example of the shift restriction, the processes from step S11 to step S12a are the same as the processes from step S11 to step S12 in the first processing example described in Fig. 10. Therefore, the description of steps S11 to S12a will be omitted.

[0108] Next, the projection device 10 determines whether or not black bands exist at the top and bottom of the currently projected projection image G1 in order to determine the content of the currently projected projection image G1 (step S12b). The black bands at the top and bottom of the projection image G1 are dark areas that appear black at the top and bottom of the image, such as when projecting a landscape-oriented movie image. Images with black bands will be described later with reference to FIG. 13.

[0109] Next, the projection device 10 refers to a shift limit table for setting a shift range of the projection image G1 based on the installation state of the projection device 10, the output value state of the light source 21, and the presence or absence of black band areas in the projection image G1 (step S13). The shift limit table to be referred to will be described later with reference to FIG. 14.

[0110] The processes from step S14 to step S15 in this second processing example are the same as the processes from step S14 to step S15 in the first processing example described in Fig. 10. Therefore, a description of steps S14 to S15 will be omitted. In this example, the presence or absence and degree of shift restriction of the projection image G1 are set based on the installation state of the projection device 10, the state of the output value of the light source 21, and the presence or absence of dark areas (black band areas) in the projection image G1.

[0111] <Example of Black Bar Regions in Projected Image G1> FIG. 13 is a diagram illustrating an example of black bar regions in the projected image G1. As shown in FIG. 13, black bar regions 62 are provided at the top and bottom edges of the projected image G1, respectively, in the form of strips that run from left to right. The brightness of the projected image G1 with the black bar regions 62 is weaker than the brightness of the projected image G1 without the black bar regions 62, so the shift range of the projected image G1 is less restricted. The brightness of the projected image G1 may be determined based on information on the presence or absence of the black bar regions 62, or may be determined based on a representative value of pixel values. Examples of the representative value of pixel values ​​include the average brightness of each pixel, the sum of the brightness of all pixels in the entire image, the median brightness of pixels, and the most frequent value. Furthermore, if the projected image G1 is a moving image, the representative value of pixel values ​​for each frame may be calculated and the brightness may be determined based on these representative values.

[0112] <Example of Shift Limit Table in Second Processing Example> Fig. 14 is a diagram showing an example of a shift limit table in the second processing example described above. The shift limit table 63 shown in Fig. 14 is a shift limit table that is referenced when black band areas exist in the upper and lower areas of the projected image G1. As shown in Fig. 14, the shift limit table 63 indicates the shift limit values ​​of the projection device 10 in a non-embedded state and the projection device 10 in a buried state at a predetermined output value of the light source 21.

[0113] For example, when the output value of the light source 21 is 100%, and the projection device 10 is in the non-embedded state, the limit of the shift range of the projection image G1 is set to −25% of the lower shift limit. On the other hand, when the projection device 10 is in the embedded state, the limit of the shift range of the projection image G1 is set to −20% of the lower shift limit. Similarly, when the output value of the light source 21 is 80%, and the limit of the shift range is set to −30% of the lower shift limit when the projection device 10 is in the non-embedded state, and the limit of the shift range is set to −25% of the lower shift limit when the projection device 10 is in the embedded state. Furthermore, when the output value of the light source 21 is 60%, and the limit of the shift range is set to −35% of the lower shift limit when the projection device 10 is in the non-embedded state, and the limit of the shift range is set to −30% of the lower shift limit when the projection device 10 is in the embedded state. When the output value of the light source 21 is 40%, the limit of the shift range is set to −40% of the lower shift limit when the projection device 10 is in an unembedded state, and the limit of the shift range is set to −35% of the lower shift limit when the projection device 10 is in an embedded state. When the output value of the light source 21 is 20%, the limit of the shift range is set to −45% of the lower shift limit when the projection device 10 is in an unembedded state, and the limit of the shift range is set to −40% of the lower shift limit when the projection device 10 is in an embedded state. Note that, in the second processing example, as in the first processing example, the installation state is one in which the object 50 on which the projection device 10 is to be installed is present below the lens 34.

[0114] In this way, when black band regions are present in the upper and lower regions of the projection image G1, a strong restriction is imposed on the shift range of the projection image G1 when the output value of the light source 21 is high, and a stronger restriction is imposed on the shift range of the projection image G1 when the installation state of the projection device 10 is recessed than when it is not recessed, as in the shift restriction table 61 referred to in the first processing example above. However, when the shift range restriction rate [%] is compared between the shift restriction table 63 in Fig. 14 and the shift restriction table 61 in Fig. 11, the shift restriction table 63 has black band regions in the upper and lower regions and the brightness of the projection image G1 is correspondingly weaker, so the shift range restriction rate is looser than that in the shift restriction table 61.

[0115] In addition, if it is determined in step S12b in the second processing example of Figure 12 that there are no black band areas in the upper or lower areas of the projection image G1, the shift limit table 61 of Figure 11 is referenced, as in the first processing example of Figure 10.

[0116] Furthermore, in this example, the shift restriction is described for the case where dark areas (black band areas) that weaken the image brightness exist in the upper and lower regions of the projected image G1 and the object 50 on which the projection device 10 is installed is located below the lens 34. However, this is not limited to this. The dark areas that weaken the image brightness may exist not only in the upper and lower end regions of the projected image G1, but also in the left and right end regions, for example. Therefore, the shift restriction of the projected image G1 may be imposed according to the direction in which the dark areas exist among the multiple end regions of the projected image G1. For example, if the dark area is located in the lower end region of the projected image G1, the downward shift range of the projected image G1 may be unrestricted or the restriction may be relaxed, and if the dark area is located in the upper end region of the projected image G1, the upward shift range of the projected image G1 may be unrestricted or the restriction may be relaxed. Furthermore, when the dark area is in the left end area of ​​the projection image G1, no restriction is imposed on the shift range of the projection image G1 to the left or the restriction is relaxed, and when the dark area is in the right end area of ​​the projection image G1, no restriction is imposed on the shift range of the projection image G1 to the right or the restriction is relaxed.

[0117] As described above, in the second example of shift restriction processing, the projection device 10 limits the range in which the projection image G1 can be shifted based on information about the installation state of the projection device 10, information about the output value of the light source 21, and information about the brightness of the content of the projection image G1. This configuration makes it possible to display the projection image G1, taking the brightness of the content into consideration, at a distance greater than a predetermined distance corresponding to the output value of the light source 21 from objects present around the lens 34 of the projection device 10. This makes it possible to more appropriately suppress ghosts 51 that may appear on objects around the lens 34 of the projection device 10 due to the projection light, such as ghosts 51 that may appear on the object 50 (floor, wall, etc.) on which the projection device 10 is installed.

[0118] Next, the limitation of the output value of the light source 21 relative to the shift position of the projection image G1 will be described.

[0119] 15 is a flowchart showing a first example of processing for limiting the output value of the light source 21 with respect to the shift position of the projection image G1. The projection device 10 starts this processing, for example, when the projection device 10 is started.

[0120] First, the projection device 10 determines the installation state of the projection device 10 (step S21). As in the case described above, the installation state of the projection device 10 refers to, for example, whether the projection device 10 is installed in a non-embedded state or an embedded state in the object 50 to be installed.

[0121] Next, the projection device 10 determines the shift position of the projection image G1 projected from the lens 34 onto the projection target 6 (step S22). The shift position of the projection image G1 refers to the shift position in the direction X or the direction Y in the projection device 10 installed as shown in FIG. 9, for example.

[0122] Next, the projection device 10 refers to an output value limit table for setting the output value of the light source 21 (LD) based on the installation state of the projection device 10 and the shift position of the projection image G1 (step S23). The output value limit table is stored in advance in the memory 4a as measured output value limit data. The output value limit table will be described later with reference to FIG. 16.

[0123] Next, the projection device 10 refers to the output value limit table to determine whether or not there is an output value limit on the projection light output from the light source 21 (step S24).

[0124] In step S24, if there is no output value limit on the projection light from the light source 21 (step S24: No), the projection device 10 ends this process. In step S24, if there is an output value limit on the projection light from the light source 21 (step S24: Yes), the projection device 10 sets an output value limit on the projection light output from the light source 21 (step S25). In this example, the presence or absence and degree of output value limit on the light source 21 are set based on the installation state of the projection device 10 and the shift position of the projection image G1.

[0125] In addition to being executed when the projection device 10 is started up, this process may be executed repeatedly after startup, when a change in the installation state of the projection device 10 is detected or when a change in the shift position of the projection image G1 is detected, or when an output value instruction is received from the user.

[0126] <Example of Output Value Limit Table in Processing Example 1> Fig. 16 is a diagram showing an example of the output value limit table in the above-described processing example 1. As shown in Fig. 16, the output value limit table 71 shows the output limit values ​​of the projection device 10 in the non-embedded state and the output limit values ​​of the projection device 10 in the embedded state at a predetermined shift position of the projection image G1.

[0127] For example, when the shift position of the projection image G1 is from 80% to 40%, the limit on the output value of the projection light from the light source 21 is set to 100% whether the projection device 10 is in an unembedded state or an embedded state. The shift position refers to the shift position in the direction Y of the projection device 10 installed, for example, as shown in FIG. 9 . A plus (+) shift position means that the shift in the direction Y is in the +Y direction, i.e., a shift in the direction away from the object 50 on which the projection device 10 is installed. A minus (−) shift position means that the shift in the direction Y is in the −Y direction, i.e., a shift in the direction toward the object 50 on which the projection device 10 is installed. A shift position of 80% means that the shift in the +Y direction is 80% of the maximum shift position (+100%). A 100% output value limit means that no ghost 51 appears even if the output value of the light source 21 is set to the maximum output value (100%).

[0128] Furthermore, when the shift position of the projection image G1 is 20%, the limit on the output value of the projection light from the light source 21 is set to 80% when the projection device 10 is in a non-embedded state, and the limit on the output value of the projection light from the light source 21 is set to 70% when the projection device 10 is in a buried state. An output value limit of 80% indicates that a ghost 51 appears when the output value of the light source 21 exceeds 80%. Similarly, when the shift position of the projection image G1 is 0%, the limit on the output value is set to 70% when the projection device 10 is in a non-embedded state, and the limit on the output value is set to 60% when the projection device 10 is in a buried state.

[0129] Furthermore, when the shift position of the projection image G1 is -20%, the output value limit is set to 60% when the projection device 10 is in a non-embedded state, and the output value limit is set to 50% when the projection device 10 is in a embedded state. A shift position of -20% means that the shift in the -Y direction is -20% of the maximum shift position (-100%). Similarly, when the shift position of the projection image G1 is -40%, the output value limit is set to 50% when the projection device 10 is in a non-embedded state, and the output value limit is set to 40% when the projection device 10 is in a embedded state. When the shift position of the projection image G1 is -60%, the output value limit is set to 40% when the projection device 10 is in a non-embedded state, and the output value limit is set to 30% when the projection device 10 is in a embedded state. When the shift position of the projection image G1 is -80%, the output value limit is set to 30% when the projection device 10 is in a non-embedded state, and the output value limit is set to 20% when the projection device 10 is in a buried state.

[0130] In this way, the more the projected image G1 is shifted in a direction closer to the object 50 on which the projection device 10 is installed, that is, the larger the negative value of the shift position, the more likely the ghost 51 will appear, and therefore a strong (strict) restriction is imposed on the output value of the light source 21. Furthermore, when the projection device 10 is installed in a recessed state, the distance between the lens 34 and the object 50 on which the projection device 10 is installed is shorter than when the projection device 10 is not recessed, and therefore the ghost 51 is more likely to appear, and a strong restriction is imposed on the output value of the light source 21.

[0131] As described above, in the first processing example of output value limitation, the projection device 10 limits the output value of the light source 21 based on information about the installation state of the projection device 10 and information about the shift position of the projection image G1. With this configuration, it is possible to limit the range of output that the light source 21 can output, depending on the shift position of the projection image G1 projected from the projection device 10. This makes it possible to suppress ghosts 51 that may appear on objects around the lens 34 of the projection device 10 based on the projection light, such as ghosts 51 that may appear on the object 50 (floor, wall, etc.) on which the projection device 10 is installed.

[0132] 17 is a flowchart showing a second example of processing for limiting the output value of the light source 21 with respect to the shift position of the projection image G1. As in the first example of processing for limiting the output value, the projection device 10 starts this processing, for example, when the projection device 10 is started up.

[0133] As shown in Fig. 17, in the second processing example of output value limitation, the processes from step S21 to step S22a are the same as the processes from step S21 to step S22 in the first processing example described in Fig. 15. Therefore, the description of steps S21 to S22a will be omitted.

[0134] Next, the projection device 10 determines whether or not there are black bands at the top and bottom of the currently projected projection image G1 in order to determine the content of the currently projected projection image G1 (step S22b). The black bands at the top and bottom of the projection image G1 are dark areas that appear black at the top and bottom of the image, such as when a horizontally long movie image is projected, as described above with reference to FIG. 13.

[0135] Next, the projection device 10 refers to an output value limit table for setting the output value of the light source 21 (LD) based on the installation state of the projection device 10, the shift position of the projection image G1, and the presence or absence of black band areas in the projection image G1 (step S23). The output value limit table will be described later with reference to FIG. 18.

[0136] The processes from step S24 to step S25 in this second processing example are the same as the processes from step S24 to step S25 in the first processing example described in Fig. 15. Therefore, a description of steps S24 to S25 will be omitted. In this example, the presence or absence and degree of output value limitation of the light source 21 is set based on the installation state of the projection device 10, the shift position of the projection image G1, and the presence or absence of dark areas (black band areas) in the projection image G1.

[0137] <Example of Output Value Limit Table in Second Processing Example> Fig. 18 is a diagram showing an example of the output value limit table in the second processing example described above. The output value limit table 72 shown in Fig. 18 is an output value limit table that is referenced when black band areas exist in the upper and lower areas of the projected image G1. As shown in Fig. 18, the output value limit table 72 shows the output limit values ​​of the projection device 10 in a non-embedded state and the output limit values ​​of the projection device 10 in a buried state at a predetermined shift position of the projected image G1.

[0138] For example, when the shift position of the projection image G1 is from 80% to 40%, the limit on the output value of the projection light from the light source 21 is set to 100% whether the projection device 10 is in an unembedded state or an embedded state. Furthermore, when the shift position of the projection image G1 is 20%, the limit on the output value of the light source 21 is set to 85% when the projection device 10 is in an unembedded state, and to 75% when the projection device 10 is in an embedded state. Similarly, when the shift position of the projection image G1 is 0%, the limit on the output value is set to 75% when the projection device 10 is in an unembedded state, and to 65% when the projection device 10 is in an embedded state. Furthermore, when the shift position of the projection image G1 is −20%, the limit on the output value is set to 65% when the projection device 10 is in an unembedded state, and to 55% when the projection device 10 is in an embedded state. When the shift position of the projection image G1 is -40%, the output value limit is set to 55% when the projection device 10 is in a non-embedded state, and the output value limit is set to 45% when the projection device 10 is in an embedded state. When the shift position of the projection image G1 is -60%, the output value limit is set to 45% when the projection device 10 is in a non-embedded state, and the output value limit is set to 35% when the projection device 10 is in an embedded state. When the shift position of the projection image G1 is -80%, the output value limit is set to 35% when the projection device 10 is in a non-embedded state, and the output value limit is set to 25% when the projection device 10 is in an embedded state.

[0139] In this way, when black band regions are provided in the upper and lower regions of the projection image G1, the output value of the light source 21 is more tightly restricted as the projection image G1 is shifted closer to the object 50 on which the projection device 10 is installed, and the output value of the light source 21 is more tightly restricted when the projection device 10 is installed in the recessed state than when it is not recessed, as in the output value restriction table 71 referred to in the first processing example above. However, when the output value restriction rate [%] is compared between the output value restriction table 72 in Fig. 18 and the output value restriction table 71 in Fig. 16, the output value restriction rate is looser than that in the output value restriction table 71 in the case of the output value restriction table 72, because black band regions are provided in the upper and lower regions and the brightness of the projection image G1 is correspondingly weaker.

[0140] In addition, if it is determined in step S22b in the second processing example of FIG. 17 that there are no black band areas in the upper or lower regions of the projection image G1, the output value limit table 71 of FIG. 16 is referenced, as in the first processing example of FIG. 15.

[0141] As described above, in the second example of output value limitation processing, the projection device 10 limits the output value of the light source 21 based on information about the installation state of the projection device 10, information about the shift position of the projection image G1, and information about the brightness of the content of the projection image G1. This configuration makes it possible to limit the range of output that the light source 21 can output, depending on the shift position of the projection image G1, which takes the brightness of the content into consideration. This makes it possible to more appropriately suppress ghosts 51 that may appear on objects around the lens 34 of the projection device 10 due to the projection light, such as ghosts 51 that may appear on the object 50 (floor, wall, etc.) on which the projection device 10 is installed.

[0142] 19 is a flowchart showing a first modified example of the shift restriction of the projection device 10. In this modified example, the presence or absence and degree of the shift restriction of the projection image G1 are set based only on the installation state of the projection device 10. The projection device 10 starts executing this process, for example, when the projection device 10 is started up, as in the first processing example of the shift restriction described above.

[0143] As shown in FIG. 19, in the first modified example of the shift restriction, the process of step S31 is the same as the process of step S11 in the first processing example described with reference to FIG.

[0144] Next, the projection device 10 refers to a shift limit table (step S32) for setting the shift range of the projection image G1 based on the installation state of the projection device 10. The shift limit table will be described later with reference to FIG.

[0145] Next, the projection device 10 refers to the shift limit table to determine whether or not there is a shift limit on the projection image G1 projected from the lens 34 (step S14).

[0146] The processes from step S33 to step S34 in this modified example are the same as the processes from step S14 to step S15 in the first processing example described with reference to FIG.

[0147] <Example of Shift Limit Table in First Modification> Fig. 20 is a diagram showing an example of a shift limit table in the above-described first modification. As shown in Fig. 20, a shift limit table 81 shows shift limit values ​​of the projection device 10 in a non-embedded state and shift limit values ​​of the projection device 10 in a buried state.

[0148] When the projection device 10 is in a non-embedded state, the limit on the shift range of the projection image G1 is set to −20% of the lower shift limit. On the other hand, when the projection device 10 is in a buried state, the limit on the shift range of the projection image G1 is set to −15% of the lower shift limit. This indicates that in a non-embedded state, ghost 51 appears when the shift amount of the projection image G1 in the −Y direction exceeds −20%, and in a buried state, ghost 51 appears when the shift amount of the projection image G1 in the −Y direction exceeds −15%. When the projection device 10 is installed in a buried state, ghost 51 is more likely to appear because the distance between the lens 34 and the object 50 on which the projection device 10 is installed is shorter than when the projection device 10 is not installed, and therefore a strong limit is imposed on the shift range of the projection image G1.

[0149] As described above, in the first modification of the shift restriction, the projection device 10 limits the range within which the projection image G1 can be shifted based on information related to the installation state of the projection device 10. This configuration makes it possible to display the projection image G1 of the projection device 10 at a necessary predetermined distance or more from objects present around the lens 34 of the projection device 10. This makes it possible to suppress ghosts 51 that may appear on objects around the lens 34 of the projection device 10 due to the projection light, such as ghosts 51 that may appear on the object 50 (floor, wall, etc.) on which the projection device 10 is installed.

[0150] <Second Modification of Shift Limit> Next, a description will be given of the control of the shift limit when there is a change in the information regarding the shift limit of the projection image G1 during projection of the projection image G1. The information regarding the shift limit includes, for example, information regarding a change in the output value of the light source 21 and information regarding a change in the installation state of the projection device 10. The information regarding the change in the output value of the light source 21 is information that indicates that the shift limit of the projection image G1 becomes stronger as the output value of the light source 21 increases, and that the shift limit of the projection image G1 becomes looser as the output value of the light source 21 decreases. The information regarding the change in the installation state of the projection device 10 is information that indicates that the shift limit of the projection image G1 becomes stronger when the projection device 10 is in an embedded state, and that the shift limit of the projection image G1 becomes looser when the projection device 10 is in an unembedded state.

[0151] If there is a change in the information regarding the shift restriction during projection of the projection image G1, the projection device 10 performs control to maintain the shift state of the projection image G1. For example, suppose the output value of the light source 21 increases during projection of the projection image G1. Even if this change in output value causes the current shift position of the projection image G1 to deviate from the shiftable range, the projection device 10 maintains the current shift position during projection of the projection image G1. In other words, even if the output value of the light source 21 increases and ghost 51 appears if the current shift position is maintained, the position of the projection image G1 is maintained unchanged during projection.

[0152] According to the second variant of the shift restriction, even if the information regarding the shift restriction changes during projection of the projection image G1, the projection position of the projection image G1 is maintained at the same position, thereby preventing the uncomfortable feeling that the position of the projection image G1 moves during projection.

[0153] However, even when the shifted state of the projection image G1 is maintained as described above, if a user operation related to the shift of the projection image G1 is performed, the shifted state of the projection image G1 is controlled to be changed in accordance with the information regarding the shift restriction. For example, suppose that the user performs an operation to change the shift position of the projection image G1 while the shifted state of the projection image G1 is maintained. In this case, even during projection of the projection image G1, the shift position of the projection image G1 is changed so that the position of the projection image G1 is within the shiftable range in response to the changed output value of the light source 21.

[0154] According to this configuration, when the user performs an operation to change the position of the projection image G1, the position of the projection image G1 is moved within the shiftable area, thereby reducing the sense of discomfort felt by the user due to the position of the projection image G1 moving during projection. Furthermore, by moving the position of the projection image G1 within the shiftable area, it is possible to reduce ghosts 51 that may appear on objects around the lens 34 of the projection device 10 due to the projection light, such as ghosts 51 that may appear on the object 50 (floor, wall, etc.) on which the projection device 10 is installed.

[0155] <Modification of the Configuration of the Projection Device 10> FIG. 21 is a diagram showing a modification of the configuration of the projection device 10. In the above-described embodiment, the control device 4 that controls the projection device 10 is provided inside the main body 101 of the projection device 10, but this is not limiting. The control device 4 may be, for example, a processor 201 (see FIG. 13 ) mounted on a personal computer 200 that is external to the projection device 10. The processor 201 may have all or some of the functions of the control device 4 in the projection device 10. The personal computer 200 is communicably connected to the projection device 10 via a signal line 10a. The personal computer 200 may also be wirelessly connected to the projection device 10.

[0156] <Hardware Configuration of Personal Computer 200> Fig. 22 is a diagram showing an example of the hardware configuration of the personal computer 200. As shown in Fig. 22, the personal computer 200 shown in Fig. 21 includes a processor 201, a memory 202, a communication interface 203, and a user interface 204. The processor 201, the memory 202, the communication interface 203, and the user interface 204 are connected by, for example, a bus 209.

[0157] The processor 201 is a circuit that performs signal processing, and is, for example, a CPU that controls the entire personal computer 200. The processor 201 may be realized by other digital circuits such as an FPGA or a DSP (Digital Signal Processor). The processor 201 may also be realized by combining multiple digital circuits.

[0158] The memory 202 includes, for example, a main memory and an auxiliary memory. The main memory is, for example, a RAM (Random Access Memory). The main memory is used as a work area for the processor 201.

[0159] The auxiliary memory is a non-volatile memory such as a magnetic disk, an optical disk, a flash memory, etc. The auxiliary memory stores various programs that operate the personal computer 200. The programs stored in the auxiliary memory are loaded into the main memory and executed by the processor 201.

[0160] The auxiliary memory may also include portable memory that is removable from the personal computer 200. Portable memory includes memory cards such as a USB (Universal Serial Bus) flash drive and an SD (Secure Digital) memory card, and an external hard disk drive.

[0161] The communication interface 203 is a communication interface that performs communication with the outside of the personal computer 200 (for example, an external communication unit of the projection device 10). The communication interface 203 is controlled by the processor 201. The communication interface 203 may be a wired communication interface that performs wired communication, a wireless communication interface that performs wireless communication, or may include both a wired communication interface and a wireless communication interface.

[0162] The user interface 204 includes, for example, an input device that accepts operation input from the user and an output device that outputs information to the user. The input device can be realized by, for example, a pointing device (for example, a mouse), keys (for example, a keyboard), or a remote control. The output device can be realized by, for example, a display or a speaker. The input device and the output device may also be realized by a touch panel or the like. The user interface 204 is controlled by the processor 201.

[0163] The control method described in the above-described embodiment can be realized by executing a prepared control program on a computer. The control program is recorded on a computer-readable storage medium and executed by being read from the storage medium. The control program may be provided in a form stored on a non-transitory storage medium such as a flash memory, or may be provided via a network such as the Internet. The computer that executes the control program may be included in the control device, or may be included in an electronic device such as a smartphone, tablet, or personal computer that can communicate with the control device, or may be included in a server device that can communicate with these control devices and electronic devices.

[0164] <Modification> Although the control by the projection device 10 and the personal computer 200 to limit the shift of the projection image depending on the installation state of the projection device 10 has been described, the projection device 10 and the personal computer 200 may perform control to limit the enlargement of the projection image depending on the installation state of the projection device 10 instead of or in addition to shifting the projection image.

[0165] Although various embodiments have been described above, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any manner as long as they do not deviate from the spirit of the invention.

[0166] This application is based on a Japanese patent application (Patent Application No. 2023-070608) filed on April 24, 2023, the contents of which are incorporated herein by reference.

[0167] REFERENCE SIGNS LIST 1 Projection unit 2 Operation reception unit 2A, 3A Hollow portion 2a, 2b, 3a, 3c, 15a Opening 4 Control device 4a, 202 Memory 6 Projected object 10 Projection device 10a Signal line 11 Projection range 12 Light modulation unit 15 Housing 21 Light source 22 Light modulation unit 23 Projection optical system 24 Control circuit 31 Second optical system 32, 122 Reflecting member 33 Third optical system 34 Lens 50 Object 51 Ghost 52 Projection room 53 Floor 54 Position 55 Bottom end 56 Area 61, 63, 81 Shift limit table 62 Black band area 71, 72 Output value limit table 101 Main body 102 First member 103 Second member 104 Projection direction change mechanism 105 Shift mechanism 106 Optical unit 121 First optical system 200 Personal computer 201 Processor 203 Communication interface 204 User interface 209 Bus G1 Projected image

Claims

1. A projection device that includes a projection lens and a processor and is capable of shifting a projected image, The processor: acquiring information about the installation state of the projection device; performing control to limit the shift of the projected image according to the installation state and the state of the light source of the projection device; Projection device.

2. 2. The projection device according to claim 1, The installation state is a state regarding a positional relationship between the projection lens and an object on which the projection device is to be installed. Projection device.

3. 2. The projection device according to claim 1, the installation state includes an embedded state in which at least a part of the projection device is embedded in an object on which the projection device is to be installed; Projection device.

4. 4. The projection device according to claim 3, the processor imposes a stronger restriction on the shift in the embedded state than in the installed state, which is different from the embedded state; Projection device.

5. 2. The projection device according to claim 1, the information about the installation state includes information about a distance between the projection lens and an object other than the projection device that is closest to the projection lens; The processor limits the shift depending on the distance. Projection device.

6. 2. The projection device according to claim 1, the information about the installation state includes information about a distance between the projection lens and an object on which the projection device is to be installed, The processor limits the shift depending on the distance. Projection device.

7. 2. The projection device according to claim 1, the processor limits the shift in a direction according to a positional relationship between the projection lens and an object on which the projection device is installed. Projection device.

8. The projection device of claim 1, The state of the light source includes a state of an output value of the light source. Projection device.

9. The projection device of claim 8, the processor imposes a stronger limit on the shift when the output value is a first output value than when the output value is a second output value that is lower than the first output value; Projection device.

10. The projection device of claim 1, the processor maintains the state of the shift if information regarding the limit of the shift changes during projection of the projection image. Projection device.

11. The projection device according to claim 10, When a user operation relating to the shift is performed while the shift state is maintained, the processor changes the shift state in accordance with information relating to the shift restriction. Projection device.

12. A projection device according to any one of claims 1 to 11, the shift is a shift in a direction perpendicular to the optical axis direction of the projection lens, Projection device.

13. A method for controlling a projection device that includes a projection lens and a processor and is capable of shifting a projected image, comprising: the processor: acquiring information about the installation state of the projection device; performing control to limit the shift of the projected image according to the installation state and the state of the light source of the projection device; Control method.

14. A control program for a projection device that includes a projection lens and a processor and is capable of shifting a projected image, comprising: the processor, acquiring information about the installation state of the projection device; performing control to limit the shift of the projected image according to the installation state and the state of the light source of the projection device; A control program for executing processing.

15. A projection device comprising a projection lens and a processor, the projection device being capable of shifting a projected image, The processor: acquiring information about the installation state of the projection device; performing control to limit the shift of the projected image according to the installation state; controlling an output value of a light source of the projection device based on the state of the shift; Projection device.

16. A method for controlling a projection device that includes a projection lens and a processor and is capable of shifting a projected image, comprising: the processor: acquiring information about the installation state of the projection device; performing control to limit the shift of the projected image according to the installation state; controlling an output value of a light source of the projection device based on the state of the shift; Control method.

17. A control program for a projection device that includes a projection lens and a processor and is capable of shifting a projected image, comprising: the processor, acquiring information about the installation state of the projection device; performing control to limit the shift of the projected image according to the installation state; controlling an output value of a light source of the projection device based on the state of the shift; A control program for executing processing.

18. A projection device comprising a projection lens and a processor, the projection device being capable of shifting a projected image, The processor: acquiring information about the installation state of the projection device; performing control to limit the shift of the projected image according to the installation state and brightness of the image content of the projected image; Projection device.

19. The projection device of claim 18, the processor limits the shift in a direction according to brightness of a plurality of edge regions in the image content of the projected image; Projection device.

20. A method for controlling a projection device that includes a projection lens and a processor and is capable of shifting a projected image, comprising: the processor: acquiring information about the installation state of the projection device; performing control to limit the shift of the projected image according to the installation state and brightness of the image content of the projected image; Control method.

21. A control program for a projection device that includes a projection lens and a processor and is capable of shifting a projected image, comprising: the processor, acquiring information about the installation state of the projection device; performing control to limit the shift of the projected image according to the installation state and brightness of the image content of the projected image; A control program for executing processing.