Projection system

Abstract

To provide a projection system capable of making distortion of a displayed image caused by distortion of an image display area, less noticeable to an observer.SOLUTION: The projection system includes: a projector 3 having a projection optical system 30 for projecting image light G; a mounting board 4 on which the projector 3 is rotatably disposed; and an angle detection unit 5 configured to detect the angle θ of a setting surface 4a of the mounting board 4, the projector 3 being set on the mounting board 4, or a bottom surface 3b of the projector 3 with respect to a predetermined reference plane P parallel to an optical axis L of the projection optical system 30. The mounting board 4 is configured such that the angle θ with respect to the reference plane P is adjustable, and the image light G projected from the projector 3 varies according to the angle θ detected by the angle detection unit 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a projection system. [Background technology]

[0002] Conventionally, an imaging system has been known that includes an angle adjustment stand device having a stand on which a projector is placed and an angle setting mechanism that allows the stand to oscillate around at least a horizontal axis while fixing it at any tilt angle (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-121918 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the angle-adjustable stand device structured as disclosed in Patent Document 1, when projecting an image, as the angle of the stand increases compared to when the angle is close to horizontal, the projected image tends to be stretched vertically, resulting in extreme distortion of the projected image. While some projectors are capable of geometric correction, particularly when used for spatial presentations, there are cases where the image is projected at an angle that geometric correction cannot adequately address. Therefore, there is a demand for projecting image light with reduced distortion, even when projecting image light at an angle relative to a three-dimensional screen, etc., to enable good spatial presentation, and there is room for improvement in this regard. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided a projection system comprising: an image projection device having a projection optical system that projects image light; a mounting member on which the image projection device is rotatably positioned; and an angle detection unit that detects the angle of the mounting surface of the mounting member on which the image projection device is placed, or the bottom surface of the image projection device, relative to a predetermined reference plane that is parallel to the optical axis of the projection optical system, wherein the mounting member is arranged so that its angle relative to the reference plane is adjustable, and the image light projected from the image projection device changes according to the angle detected by the angle detection unit. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a side view showing the configuration of a projection system according to a first embodiment of the present invention. [Figure 2] FIG. 4 is a plan view showing first image information before projection and image light on a screen after projection. [Figure 3] FIG. 1 is a perspective view of a transport device equipped with a projector. [Figure 4] FIG. 4 is a side view of the transport device shown in FIG. 3. [Figure 5] FIG. 4 is a side view showing an example of a rotation mechanism for the mounting table. [Figure 6] FIG. 10 is a side view showing another example of the rotation mechanism of the mounting table. [Figure 7] FIG. 2 is a block diagram showing an example of a processing unit in the projection system. [Figure 8] 10 is a flowchart of image processing using the processing unit. [Figure 9] FIG. 10 is a side view showing the configuration of a projection system according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings below, the dimensions of the components may be shown on different scales to make them easier to see.

[0008] (First embodiment) As shown in FIG. 1, the projection system 1 of the embodiment includes a screen 2 onto which image light G is projected, a projector 3 (image projection device) having a projection optical system 30 that projects the image light G, and a mounting base 4 (mounting member) on which the projector 3 is rotatably positioned.

[0009] Here, the reference plane P is the plane that is parallel to the optical axis L of the projection optical system 30 and is in the plane direction of the installation surface 4a (or the bottom surface 3b of the projector 3) when the plane direction of the installation surface 4a on which the projector 3 is installed on the mounting base 4 is horizontal.

[0010] Fig. 2 is a plan view showing the first image information G1 before projection and the image light Gb on the screen 2 after projection. In Fig. 2, the lower left diagram shows the image light Ga when the optical axis L of the projector 3 is in the horizontal position and the angle θ due to rotation is 0°, and the upper left diagram shows the first image information G1 obtained by processing the image light Ga by the processing unit 6, which will be described later, in accordance with the angle θ formed between the reference plane P and the installation surface 4a of the mounting base 4. Furthermore, the lower right diagram shows the image light Ga on the screen 2 when the optical axis L of the projector 3 is in the horizontal position and the angle θ due to rotation is 0°, and the upper right diagram shows the image light Gb on the screen 2 onto which the first image information G1 is projected.

[0011] In the following figures, three mutually orthogonal axes will be referred to as the X-axis, Y-axis, and Z-axis. The direction along the X-axis will be referred to as the "X direction," the direction along the Y-axis as the "Y direction," and the direction along the Z-axis as the "Z direction." The direction of the arrow is the + direction, and the direction opposite the + direction is referred to as the - direction. Note that the +Z direction is sometimes referred to as "up" or "upward," and the -Z direction as "down" or "downward," and the view from the +Z direction is also referred to as a planar view. In addition, the surface on the +Z side will be referred to as the top surface, and the surface opposite this on the -Z side will be referred to as the bottom surface.

[0012] 1, the projection system 1 includes an angle detection unit 5 that detects an angle θ of the installation surface 4a of the mounting base 4 (or the bottom surface 3b of the projector 3) with respect to a reference plane P. In the present embodiment, the following description will be given assuming that the detection target of the angle detection unit 5 is the installation surface 4a of the mounting base 4.

[0013] The screen 2 is not particularly limited to a material, but may be made of a flexible, semi-transparent material. The screen 2 may be a wall surface such as a ceiling or side surface in a room. In this embodiment, the projection surface 2a of the screen 2 is perpendicular to the optical axis L of the projector 3.

[0014] 3 and 4, the projector 3 projects an image onto the screen 2. The projector 3 can be moved together with a mounting base 4 by a transport cart 40, and is used, for example, to project and display image light G onto the screen 2. A projection lens 31 of a projection optical system 30 is disposed on a front surface 3a of the projector 3.

[0015] The projector 3 is rotatably fixed on a mounting base 4. A bottom surface 3b of the projector 3 is placed on and fixed to an installation surface 4a of the mounting base 4. The bottom surface 3b of the projector 3 and the installation surface 4a are parallel to each other. As shown in FIG. 1, the optical axis L of the image light G projected from the projection lens 31 is horizontal when the installation surface 4a is at the same angle as the reference plane P (angle θ = 0°). The image light G projected from the projector 3 becomes first image information G1 (described later) that has been image-processed by a processing unit 6 (described later) so that the image information G1 changes according to the angle θ detected by the angle detection unit 5. That is, the image light G projected from the projector 3 is normal image light G when the optical axis L is horizontal. However, by image-processing by the processing unit 6 to remove distortion caused by vertical stretching of the projected image when the projector 3 is rotated up or down by a predetermined angle θ, the projected image at a position where the projector 3 is rotated by the predetermined angle is also projected as distortion-free image light Gb (see FIG. 2).

[0016] 3 and 4, the transporting cart 40 can be transported together with the projector 3 by moving it manually, for example. The transporting cart 40 includes a plate-shaped mounting base 4 to which the projector 3 is fixed, a rotary shaft member 42 that rotatably supports the mounting base 4 within a predetermined rotation angle range, a pair of side panels 43 that have the rotary shaft member 42 and rotatably support the mounting base 4 via the rotary shaft member 42, and a bottom panel 44 that has wheels 45 and supports the side panels 43 from below in the vertical direction. The transporting cart 40 is provided so that the mounting base 4 can be adjusted to any angle θ with respect to a reference plane P.

[0017] When the mounting base 4 is horizontal, the X direction perpendicular to the rotation axis C1 of the rotation shaft member 42 is also called the front-rear direction X, and the direction in which the projection lens 31 of the projector 3 is arranged in the front-rear direction X (the direction in which the projection lens 31 faces the screen 2) is called the front or front side X1, and the opposite side is called the rear or rear side X2. In addition, the Y direction along the rotation axis C1 is also called the left-right direction Y, and the direction going around the rotation axis C1 is called the circumferential direction.

[0018] The mounting base 4 is provided so that the angle θ with respect to the reference plane P can be adjusted, and is supported by a pair of side plates 43 so that it can rotate circumferentially around a rotation axis C1. The mounting base 4 is shaped like a plate with a certain thickness. An upper wall 41 is provided integrally above the mounting base 4, parallel to and facing the mounting base 4. The distance between the mounting base 4 and the upper wall 41 is set to be at least greater than the height of the projector 3. The space between the mounting base 4 and the upper wall 41 serves as a storage area for the projector 3 fixed to the installation surface 4a of the mounting base 4. When the installation surface 4a, which is the upper surface of the mounting base 4, is in a horizontal position, the installation surface 4a faces vertically upward.

[0019] The projector 3 is attached to the installation surface 4a of the installation base 4 by means of fixing screws (not shown) or the like. The projector 3 is attached to the installation base 4 with the bottom surface 3b placed on the installation surface 4a.

[0020] The rotary shaft members 42 are provided between the mounting table 4 and each of the pair of side plates 43 . One or both of the pair of side plates 43 are provided with a plurality of circular engagement holes 43a spaced at regular intervals in the circumferential direction along an arc centered on the rotation axis C1. The engagement holes 43a penetrate the side plate 43 in the thickness direction. The positions at which the plurality of engagement holes 43a are arranged overlap with the trajectory of a stopper pin 48 provided on the top wall 41 of the mounting table 4 that rotates together with the mounting table 4. The stopper pin 48 is provided on the top wall 41 so as to be able to protrude outward in the direction of the rotation axis C1. The stopper pin 48 can tilt the mounting table 4 at a predetermined rotation angle by selectively engaging with one of the engagement holes 43a.

[0021] 3, a grip member 46 extending in the left-right direction Y is provided on the upper rear part of the transporting cart 40. When moving the projector 3 together with the mounting base 4, the user can move the transporting cart 40 by gripping the grip member 46.

[0022] As shown in FIG. 5, the loading platform 4 may have a rotation axis C1 on the rear side X2 of the transporting platform 40, allowing the front side X1 to rotate in the vertical direction, or may have a rotation axis C1 on the front side X1 of the transporting platform 40, allowing the rear side X2 to rotate in the vertical direction (Z direction).

[0023] The projection system 1 is provided so that the image light G projected from the projector 3 changes in accordance with the angle θ detected by the angle detection unit 5.

[0024] The angle detection unit 5 employs an angle sensor or the like that detects the angle θ formed between the reference plane P and the installation surface 4a of the mounting base 4. An example of an angle sensor is a rotary potentiometer. The angle θ detected by the angle detection unit 5 is the angle in the rotation direction around the rotation axis C1 with respect to the reference plane P. Furthermore, the detection target for the angle θ detected by the angle detection unit 5 is not limited to the installation surface 4a of the mounting base 4, but may also be the bottom surface 3b of the projector 3.

[0025] 5, the projector 3 further includes a processing unit 6 that outputs first image information G1 that is changed in accordance with the angle θ detected by the angle detection unit 5. In this embodiment, the processing unit 6 is provided separately from the projector 3. The processing unit 6 is installed on a support base 47 that is disposed below the mounting base 4. Note that the processing unit 6 may also be provided integrally with the projector 3.

[0026] 7 shows an example of the processing unit 6. The processing unit 6 is capable of transmitting and receiving information to and from the projector 3 and an angle sensor of the angle detection unit 5 that detects the angle θ of the angle adjustment mechanism, which is the installation surface 4a of the mounting base 4. The processing unit 6 includes a processor 61, a memory 62, a display mechanism 63, an audio output mechanism 64, and an interface mechanism 65. The processor 61 has an angle detection unit 611, an angle determination unit 612, detection units 613 and 614, an image selection unit 615, and an image adjustment unit 616.

[0027] The processing unit 6 receives angle information detected by the angle sensor (angle detection unit 5) and switches the projection content (first image information G1, described later) based on the received angle information (angle θ). In this case, "switching the content" includes processing the projected image into an image that is less likely to cause discomfort to the user even if it is stretched, and switching the projected image itself to a completely different one.

[0028] The processing unit 6 stores a plurality of pieces of first image information G1 (see FIG. 2) corresponding to a plurality of angles relative to the reference plane P in the memory 62, and selects and outputs the first image information G1 from the plurality of pieces of first image information G1 based on the angle detected by the angle detection unit 5. The plurality of pieces of first image information G1 employs image information that is gradually reduced in the direction of rotation of the projector 3 (vertical direction Z) as the angle θ formed between the reference plane P and the installation surface 4a of the mounting base 4 increases.

[0029] A threshold value may be set for the angle θ in the processing unit 6. This threshold value is a constant that is set in advance in the processing unit 6. In the processing unit 6, when the angle θ detected by the angle detection unit 5 in the angle determination unit 612 exceeds a predetermined first threshold value, the processing unit 6 outputs the first image information G1 that has been changed according to the angle θ. In addition, when the angle θ detected by the angle detection unit 5 is smaller than a second threshold value, the processing unit 6 outputs the first image information G1 that has been changed according to the angle θ.

[0030] Note that when the angle determination unit 612 determines whether the angle θ is greater than or less than the threshold, the determination order may be either first or second. Furthermore, when the angle θ of the projector 3 is changed, it is not necessary to compare whether the angle θ is greater than or less than a predetermined first threshold. For example, if the angle θ decreases from the original angle, it may be possible to compare only whether the detected value is less than the second threshold. If the angle θ increases from the original angle, it may be possible to compare only whether the detected value is greater than the first threshold. This reduces the amount of processing in the processing unit 6. Furthermore, the threshold is not limited to one, and the first image information G1 may be switched between, for example, three levels. Furthermore, the threshold is not limited to a preset value, and may be determined for each piece of first image information G1 to be projected, or may be arbitrarily set by the user.

[0031] FIG. 8 is a flowchart of image processing using the processing unit 6 in the projection system 1. 8, when the installation surface 4a of the mounting table 4, i.e., the angle of the projector 3, is changed in step S1, the angle θ formed between the reference plane P and the installation surface 4a at that time is detected by the angle detection unit 5 (step S2). Next, the processing unit 6 determines whether the detected angle θ is greater than a first threshold value (step S3). If the angle θ is greater than the first threshold value (step S3: YES), the process proceeds to step S5. On the other hand, if the angle θ is smaller than the first threshold value (step S3: NO), the processing unit 6 determines whether the detected angle θ is smaller than a second threshold value (step S4).

[0032] If the angle θ is smaller than the second threshold value in step S4 (step S4: YES), the process proceeds to step S5. In step S5, the first image information G1 is selected from the plurality of first image information G1 stored in the processing unit 6 based on the angle θ detected by the angle detection unit 5 in step S2 and output. Note that if the angle θ is larger than the second threshold value in step S4 (step S3: NO), the process by the processing unit 6 ends. In this way, in step S5, the image light G (first image information G1) that has been switched from the image light G projected before the angle was changed to the content corresponding to the detected angle θ is projected from the projector 3 onto the screen 2.

[0033] Next, the operation of the projection system 1 will be described.

[0034] 1, the projection system 1 of this embodiment includes a projector 3 having a projection optical system 30 that projects image light G, a mounting base 4 on which the projector 3 is rotatably disposed, and an angle detection unit 5 that detects an angle θ of an installation surface 4a on which the projector 3 is installed on the mounting base 4 or a bottom surface 3b of the projector 3 with respect to a predetermined reference plane P that is parallel to the optical axis L of the projection optical system 30. The mounting base 4 is provided so that the angle θ with respect to the reference plane P is adjustable, and the image light G projected from the projector 3 changes according to the angle θ detected by the angle detection unit 5.

[0035] Therefore, in this embodiment, even if the projector 3 rotates and the projection angle changes, and the angle θ formed between the installation surface 4a of the mounting base 4 or the bottom surface 3b of the projector 3 and the reference plane P becomes large, the angle θ can be detected by the angle detection unit 5, and the projected image can be changed according to the angle θ, and image light G suitable for the angle θ can be projected. Therefore, it is possible to make it difficult for the viewer to visually recognize distortion of the displayed image caused by distortion of the image display area, and more advanced spatial presentation can be realized.

[0036] Furthermore, in the projection system 1 according to this embodiment, the projector 3 further includes a processing unit 6 that outputs the first image information G1 that has been changed in accordance with the angle θ detected by the angle detection unit 5. In this way, the first image information G1 can be changed by the processing unit 6 of the projector 3 in accordance with the detected angle θ and output. Furthermore, by providing the processing unit 6 in the projector 3, there is no need to provide a separate processing device, and the projector can be made more compact.

[0037] According to the projection system 1 of this embodiment, a plurality of pieces of first image information G1 corresponding to a plurality of angles θ with respect to the reference plane P are stored in the processing unit, and the processing unit selects and outputs the first image information G1 from the plurality of pieces of first image information G1 based on the angle θ detected by the angle detection unit 5. Therefore, rather than performing image processing on the original image, the processing unit 6 selects the first image information G1 corresponding to the detected angle θ from the plurality of pieces of first image information G1 previously stored in the processing unit 6, and switches to the selected first image information G1, thereby simplifying the processing in the processing unit 6.

[0038] According to the projection system 1 of this embodiment, a threshold value is set for the angle θ in the processing unit, and when the angle θ detected by the angle detection unit 5 exceeds the threshold value, the processing unit outputs first image information G1 that has been changed according to the angle θ. In this case, when the detected angle θ increases, the angle θ can be determined by comparing whether the detected value (angle θ) is greater than the threshold value, and image processing can be performed according to the determined angle range. This simplifies the processing related to angle determination and the like in the processing unit 6.

[0039] According to the projection system 1 of this embodiment, when the angle θ detected by the angle detection unit 5 is smaller than the threshold value, the processing unit outputs the first image information G1 that has been changed according to the angle θ. In this case, even when the detected angle θ becomes small, the angle θ can be determined by comparing whether the detected value (angle θ) is smaller than the threshold value, and image processing can be performed according to the determined angle range. This simplifies the processing related to angle determination, etc. in the processing unit 6.

[0040] According to the projection system 1 of this embodiment, the threshold value is a constant that is set in advance by the processing unit 6. In this case, since the threshold value is a constant, there is no need for a user to set it or for processing to change the threshold value in accordance with image information, which simplifies the processing in the processing unit.

[0041] (Second embodiment) The projection system according to the second embodiment employs a processing method that outputs first image information obtained by processing second image information input to a processing unit or a projector (image projection device). The second image information is a projected image before the projector (image projection device) is rotated. That is, as the angle θ detected by the angle detection unit increases, the processing unit or the projector gradually reduces the image of the second image information in the direction of rotation of the projector, and outputs the first image information.

[0042] In the second embodiment, unlike the first embodiment in which a plurality of first image information items stored in advance in a processing unit are selected and switched to, the size of the second image information item can be adjusted by image processing to switch to the first image information item. Therefore, there is no need to prepare multiple contents, and advanced spatial presentation can be easily achieved.

[0043] In addition, in this embodiment, in the direction in which the angle occurs (the direction in which the image light is stretched), the image of the second image information is reduced and switched to the first image information, making it easier for the viewer to identify the information in the image light, and enabling advanced spatial presentation.

[0044] (Variation) 9, the projection system 1A according to the modification shown in FIG. 9 is configured so that the screen 2A onto which the image light G is projected is provided with a variable screen angle α relative to the optical axis L of the projection optical system 30 of the projector 3. The projection system 1A is configured so that the image light G is changed according to the relative angle between the screen angle α formed between the optical axis L and the projection surface 2a of the screen 2A and the angle θ formed between the reference plane P and the projector 3 (image projection device).

[0045] That is, the conditions for changing the image light G in the modified example are the angle θ detected by the angle detection unit 5 on the projector 3 side and the screen angle α detected by a screen angle detection unit (not shown) that detects the screen angle α. Depending on the angle information of the angle θ and the screen angle α, for example, a method can be employed in which a plurality of pieces of first image information are stored in a processing unit as in the first embodiment described above, and the first image information corresponding to the angle information is selected from the plurality of pieces of first image information and projected, or a method can be employed in which the second image information input in accordance with the angle information is reduced and changed and projected, as in the second embodiment described above. In this way, even when the angle of the screen 2A changes as in the modified example, it is possible to make it difficult for the viewer to see distortion in the displayed image due to distortion in the image display area, thereby achieving more advanced spatial presentation.

[0046] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

[0047] In the above-described embodiment, the rotation direction of the installation surface 4a of the mounting table 4 is the vertical direction, but it can also be applied to a case where the mounting table 4 rotates left and right with the rotation axis facing up and down.

[0048] Furthermore, in the first embodiment, it is not necessary to perform image processing on the first image information G1 in the processing unit 6. For example, if the projector 3 includes a processor, the processor of the projector 3 may control the switching.

[0049] Furthermore, the configuration of the transport vehicle 40 is not limited to the configuration of the above-described embodiment, and can be modified as appropriate.

[0050] A summary of this disclosure is provided below. (Appendix 1) an image projection device having a projection optical system that projects image light; a mounting member on which the image projection device is rotatably disposed; an angle detection unit that detects an angle of the mounting member with respect to a predetermined reference plane that is parallel to the optical axis of the projection optical system, the mounting surface on which the image projection device is placed or the bottom surface of the image projection device; the mounting member is provided so that its angle with respect to the reference plane can be adjusted, the image light projected from the image projection device changes according to the angle detected by the angle detection unit; A projection system characterized by:

[0051] According to the projection system having the configuration of Supplementary Note 1, even when the image projection device rotates and the projection angle changes, causing the angle between the installation surface of the mounting member or the bottom surface of the image projection device and the reference plane to become larger, the angle can be detected by the angle detection unit, and the projected image can be changed according to the angle, so that image light appropriate for the angle can be projected. Therefore, distortion of the displayed image caused by distortion of the image display area can be made less noticeable to the viewer, and more advanced spatial presentation can be achieved.

[0052] (Appendix 2) The image projection device further includes a processing unit that outputs first image information that has been changed in accordance with the angle detected by the angle detection unit. 2. The projection system according to claim 1,

[0053] According to the configuration of Supplementary Note 2, the detected angle can be converted into the first image information by the processing unit of the image projection device and output. Also, by providing the processing unit in the image projection device, there is no need to provide a separate processing device, which can lead to miniaturization.

[0054] (Appendix 3) The first image information is output by changing the input second image information through image processing. 3. The projection system according to claim 2,

[0055] According to the configuration of Supplementary Note 3, the size of the second image information can be adjusted by image processing to switch to the first image information. Therefore, there is no need to prepare multiple contents, and advanced spatial presentation can be easily achieved.

[0056] (Appendix 4) the processing unit stores a plurality of pieces of first image information corresponding to a plurality of angles with respect to the reference plane, and selects and outputs the first image information based on the angle detected by the angle detection unit from the plurality of pieces of first image information. 3. The projection system according to claim 2,

[0057] According to the configuration of Appendix 4, instead of performing image processing on the original image, the processing method selects the first image information corresponding to the detected angle from multiple first image information stored in the processing unit in advance, and switches to the selected first image information, thereby simplifying the processing in the processing unit.

[0058] (Appendix 5) a threshold value is set for the angle in the processing unit; When the angle detected by the angle detection unit exceeds the threshold value, the processing unit outputs the first image information changed according to the angle. 5. The projection system according to any one of claims 2 to 4,

[0059] According to the configuration of Supplementary Note 5, when the detected angle becomes large, the angle can be determined by comparing whether the detected value (angle) is larger than a threshold value or not, and image processing can be performed according to the determined angle range. Therefore, the processing related to angle determination etc. in the processing unit can be simplified.

[0060] (Appendix 6) When the angle detected by the angle detection unit is smaller than the threshold value, the processing unit outputs the first image information changed according to the angle. 6. The projection system according to claim 5,

[0061] According to the configuration of Supplementary Note 6, even when the detected angle becomes small, the angle can be determined by comparing whether the detected value (angle) is smaller than the threshold value, and image processing can be performed according to the determined angle range. Therefore, the processing related to angle determination, etc. in the processing unit can be simplified.

[0062] (Appendix 7) the processing unit gradually reduces the image of the second image information in the direction of rotation of the image projection device as the angle increases, and outputs the first image information. 4. The projection system according to claim 3,

[0063] According to the configuration of Appendix 7, in the direction in which the angle occurs (the direction in which the image light is stretched), the image of the second image information is reduced and switched to the first image information, making it easier for the viewer to identify the information in the image light and enabling advanced spatial presentation.

[0064] (Appendix 8) The threshold value is a constant that is preset in the processing unit. 6. The projection system according to claim 5,

[0065] According to the configuration of Supplementary Note 8, since the threshold is a constant, there is no need for a user to set it or for processing to change the threshold in accordance with image information, and the processing in the processing unit can be simplified.

[0066] (Appendix 9) further comprising a screen onto which the image light is projected; the screen is provided so that a screen angle relative to the optical axis of the projection optical system can be changed; changing the image light in accordance with a relative angle between the screen angle formed by the optical axis and the projection surface of the screen and the angle formed by the reference surface and the image projection device; 2. The projection system according to claim 1,

[0067] According to the configuration of Supplementary Note 9, even when the angle of the screen changes, distortion of the displayed image caused by distortion of the image display area can be made less visible to the observer, thereby realizing more advanced spatial presentation. [Explanation of symbols]

[0068] REFERENCE SIGNS LIST 1, 1A... projection system, 2, 2A... screen, 3... projector (image projection device), 3b... bottom surface, 4... mounting base (mounting member), 4a... installation surface, 5... angle detection unit, 6... processing unit, 30... projection optical system, 40... transport vehicle, G... image light, G1... first image information, L... optical axis, P... reference plane, θ... angle, α... screen angle

Claims

1. an image projection device having a projection optical system that projects image light; a mounting member on which the image projection device is rotatably disposed; an angle detection unit that detects an angle of an installation surface of the mounting member on which the image projection device is installed or a bottom surface of the image projection device with respect to a predetermined reference plane that is parallel to the optical axis of the projection optical system, the mounting member is provided so that its angle with respect to the reference plane can be adjusted, the image light projected from the image projection device changes according to the angle detected by the angle detection unit; A projection system characterized by:

2. the image projection device further includes a processing unit that outputs first image information that has been changed in accordance with the angle detected by the angle detection unit.

2. The projection system according to claim 1, wherein:

3. The first image information is output by changing the input second image information through image processing.

3. The projection system according to claim 2, wherein:

4. the processing unit stores a plurality of pieces of first image information corresponding to a plurality of angles with respect to the reference plane, and selects and outputs the first image information based on the angle detected by the angle detection unit from the plurality of pieces of first image information.

3. The projection system according to claim 2, wherein:

5. a threshold value is set for the angle in the processing unit; When the angle detected by the angle detection unit exceeds the threshold value, the processing unit outputs the first image information changed according to the angle.

5. The projection system according to claim 2, wherein the projection system comprises: a first projection unit;

6. When the angle detected by the angle detection unit is smaller than the threshold value, the processing unit outputs the first image information changed according to the angle.

6. The projection system according to claim 5, wherein:

7. As the angle increases, the image of the second image information is gradually reduced in the direction of rotation of the image projection device, and the first image information is output.

4. The projection system according to claim 3, wherein:

8. The threshold value is a constant that is preset in the processing unit.

6. The projection system according to claim 5, wherein:

9. further comprising a screen onto which the image light is projected; the screen is provided so that a screen angle relative to the optical axis of the projection optical system can be changed; changing the image light in accordance with a relative angle between the screen angle formed by the optical axis and the projection surface of the screen and the angle formed by the reference surface and the image projection device; 2. The projection system according to claim 1, wherein:

Images