Display methods, projectors, and projection systems

Abstract

A display method, projector, and projection system are provided. In multi-projection scenarios, the display quality of the image in the overlapping area is prevented from deteriorating by suppressing the impact of projector vibration on the brightness of the overlapping area of ​​multiple projected images. The image display method includes: when the projector's position is a reference position, attenuating the brightness of the image in the first image corresponding to the overlapping area based on a first attenuation coefficient determined according to the position within the overlapping area; when the projector's position has shifted from the reference position, calculating displacement information related to the projector's displacement based on an output signal from an inertial sensor; correcting the first attenuation coefficient based on the displacement information; and when the projector's position has shifted from the reference position, attenuating the brightness of the image in the first image corresponding to the overlapping area based on the corrected first attenuation coefficient.

Description

Technical Field

[0001] This invention relates to display methods, projectors, and projection systems. Background Technology

[0002] In multi-projection scenarios using multiple projectors, if at least one projector vibrates, the projected images from each projector will deviate from each other. Therefore, conventional techniques for correcting this deviation have been used in multi-projection processes.

[0003] For example, Patent Document 1 discloses a multi-projection technology in which multiple projectors project detection images for detecting deviations in the projection range. In the technology of Patent Document 1, while the aforementioned detection images are projected, an imaging unit captures images of overlapping areas where the projection ranges of each projector overlap. Next, a detection unit detects the deviation of the projected images based on the images captured by the imaging unit. Finally, based on the detected deviation, a deviation correction unit processes the image signal to offset the projection range by a predetermined amount.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2012-165091

[0005] In the overlapping region, since two display images are combined, the blending ratio of the two display images is generally predetermined. When a projector vibrates, the position of the overlapping region deviates from its original position. However, the technology in Patent Document 1 only shifts the projection range through image signal processing; therefore, even if the display image can be displayed in the shifted overlapping region, it will be displayed according to the blending ratio corresponding to the original overlapping region. As a result, the display quality of the image in the overlapping region sometimes deteriorates. Summary of the Invention

[0006] One aspect of the present invention provides an image display method comprising the following processing: when the position of a projector is a reference position, attenuating the brightness of an image corresponding to an overlapping area of ​​a first image displayed by the projector on a display surface and an overlapping area of ​​a second image displayed by another projector on the display surface based on a first attenuation coefficient determined according to the position within the overlapping area; when the position of the projector is displaced from the reference position, correcting the first attenuation coefficient based on displacement information related to the displacement of the projector calculated based on the output signal of an inertial sensor fixed to the projector; and when the position of the projector is displaced from the reference position, attenuating the brightness of the image corresponding to the overlapping area in the first image based on the corrected first attenuation coefficient.

[0007] One aspect of the present invention provides a projector comprising a processing device programmed to perform the following processing: when the position of the projector is a reference position, attenuating the brightness of an image corresponding to an overlapping region on the display surface of a first image displayed by the projector and a second image displayed by another projector, based on a first attenuation coefficient determined according to the position within the overlapping region; when the position of the projector is displaced from the reference position, correcting the first attenuation coefficient based on displacement information related to the displacement of the projector calculated based on the output signal of an inertial sensor fixed to the projector; and when the position of the projector is displaced from the reference position, attenuating the brightness of the image corresponding to the overlapping region in the first image based on the corrected first attenuation coefficient.

[0008] One aspect of the projection system of the present invention includes: a first projector displaying a first image on a display surface; and a second projector displaying a second image on the display surface. The first projector includes a processing device programmed to perform the following processing: when the position of the first projector is a reference position, attenuating the brightness of an image in the first image corresponding to an overlapping region of the first image and the second image on the display surface based on a first attenuation coefficient determined according to the position within the overlapping region; when the position of the first projector is displaced from the reference position, correcting the first attenuation coefficient based on displacement information related to the displacement of the first projector calculated based on the output signal of an inertial sensor fixed to the first projector; and when the position of the first projector is displaced from the reference position, attenuating the brightness of the image in the first image corresponding to the overlapping region based on the corrected first attenuation coefficient.

[0009] A projection system according to one aspect of the present invention includes: a first projector displaying a first image on a display surface; and a second projector displaying a second image on the display surface. The first projector includes: a first attenuation unit that, when the position of the first projector is a reference position, attenuates the brightness of an image in the first image corresponding to an overlapping region that overlaps the first image and the second image on the display surface based on a first attenuation coefficient determined according to the position within the overlapping region; and a calculation unit that, when the position of the first projector shifts from the reference position, calculates a position related to the position of the overlapping region on the display surface based on displacement information related to the displacement of the first projector calculated based on an output signal of an inertial sensor fixed to the first projector. The second projector includes: an information output unit that outputs the position information to a second projector; and a correction unit that corrects the first attenuation coefficient based on the displacement information. When the position of the first projector shifts from the reference position, the first attenuation unit attenuates the brightness of the image in the first image corresponding to the overlapping region based on the corrected first attenuation coefficient. The second projector further includes: a second attenuation unit that attenuates the brightness of the image in the second image corresponding to the overlapping region based on a second attenuation coefficient determined according to the position within the overlapping region; an information acquisition unit that acquires the position information; and a correction unit that corrects the second attenuation coefficient based on the position information. The second attenuation unit attenuates the brightness of the second image based on the corrected second attenuation coefficient. Attached Figure Description

[0010] Figure 1 This is a block diagram showing the overall structure of the projection system 1 according to the first embodiment.

[0011] Figure 2 This is a block diagram illustrating a structural example of the control device 10.

[0012] Figure 3 This is a diagram showing an example of a first display image 81 and a second display image 82.

[0013] Figure 4 This is a block diagram illustrating a structural example of the first projector 20.

[0014] Figure 5 This is an explanatory diagram of the correction method for the first attenuation coefficient performed by the correction unit 235.

[0015] Figure 6 This is an explanatory diagram of the correction method for the first attenuation coefficient performed by the correction unit 235.

[0016] Figure 7This is an explanatory diagram of the correction method for the first attenuation coefficient performed by the correction unit 235.

[0017] Figure 8 This is a block diagram illustrating a structural example of the second projector 30.

[0018] Figure 9 This is a timing diagram representing an example of the operation of projection system 1.

[0019] Figure 10 This is a schematic diagram showing the overall structure of the projection system 1A according to the second embodiment.

[0020] Figure 11 This is a block diagram illustrating a structural example of the first projector 20A.

[0021] Figure 12 This is a block diagram illustrating a structural example of the second projector 30A.

[0022] Figure 13 This is an explanatory diagram of the correction method for the second attenuation coefficient performed by the correction unit 336.

[0023] Figure 14 This is a timing diagram illustrating an example of the operation of projection system 1A.

[0024] Label Explanation

[0025] 1, 1A: Projection system; 10: Control device; 11: Processing device; 12: Storage device; 13: Display device; 14: Input device; 15: Communication device; 20, 20A: First projector; 21: Sensor; 22: Projection device; 23, 23A: Processing device; 24: Storage device; 25: Communication device; 30, 30A: Second projector; 32: Projection device; 33, 33A: Processing device; 34: Storage device; 35: Communication device; 40A: Third projector; 50A: Fourth projector; 60: Connecting cable; 70: Display surface; 71, 73: Overlapping area; 74: Overlapping area; 75: Area; 81: First displayed image; 82: Second displayed image; 83: Composite image; 85: Second displayed image ; 91, 92, 93, 94, 95: Gain curves; 95A: Linear section; 95B: Curved section; 111: First image generation section; 112: Second image generation section; 113: First attenuation coefficient generation section; 114: Second attenuation coefficient generation section; 115: Information output section; 120: Processing device; 231: Overlap section; 232: First attenuation section; 233, 233A: Calculation section; 234: Image movement section; 235: Correction section; 236: Speed ​​readout section; 237: Image output section; 238: Information output section; 331: Overlap section; 332: Second attenuation section; 333: Speed ​​readout section; 334: Image output section; 335: Information acquisition section; 336: Correction section; PR1, PR2, PR3: Control program. Detailed Implementation

[0026] Hereinafter, the image display method, projector, and projection system of the embodiments will be described with reference to the accompanying drawings. Furthermore, in each drawing, the dimensions and scales of the various parts differ appropriately from the actual dimensions and scales. Additionally, the embodiments described below are preferred examples, and therefore various technically preferred limitations have been added; however, unless otherwise specified in the following description, the scope of this disclosure is not limited to these methods.

[0027] 1. First Implementation Method

[0028] 1-1. Overall Structure

[0029] Figure 1 This is a block diagram showing the overall structure of the projection system 1 according to the first embodiment. The projection system 1 includes a control device 10 and a first projector 20 and a second projector 30, which are multiple projectors. Furthermore, for the sake of simplicity, in... Figure 1 In the example shown, projection system 1 has a first projector 20 and a second projector 30 as two projectors. However, the number of projectors in projection system 1 is not limited to two, and can also be three or more.

[0030] In projection system 1, control device 10 controls first projector 20 and second projector 30. Control device 10 roughly divides an image into two parts and outputs the divided images to first projector 20 and second projector 30 respectively. First projector 20 and second projector 30 display the image on the display surface by projecting the divided images onto the display surface. The display surface can be a wall or a screen, but is not limited to these.

[0031] 1-2. Structure of Control Device 10

[0032] Figure 2 This is a block diagram illustrating a structural example of the control device 10. The control device 10 is typically a PC, but is not limited to this; for example, it could also be a tablet or a smartphone. The control device 10 includes a processing unit 11, a storage unit 12, a display unit 13, an input unit 14, and a communication unit 15. The various elements of the control device 10 are interconnected via one or more individual buses for communicating information.

[0033] The processing device 11 is a processor that controls the entire control device 10, and may be composed of one or more chips. The processing device 11 may be, for example, a central processing unit (CPU) that includes interfaces with peripheral devices, arithmetic units, and registers. Alternatively, some or all of the functions of the processing device 120 may be implemented using hardware such as a DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), or FPGA (Field Programmable Gate Array). The processing device 11 executes various processes in parallel or sequentially.

[0034] Storage device 12 is a recording medium that can be read by processing device 11, storing multiple programs including control program PR1 executed by processing device 11. Additionally, storage device 12 stores images projected by first projector 20 and second projector 30. Furthermore, storage device 12 may also store layout information related to the configuration of first projector 20 and second projector 30. Storage device 12 may be composed of at least one of the following: ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory). Storage device 12 may also be referred to as a register, cache, main memory, or main storage device.

[0035] Display device 13 is a device for displaying images and text information. Display device 13 displays various images under the control of processing device 11. For example, various display panels such as liquid crystal display panels and organic EL (Electro Luminescence) display panels are suitable for use as display device 13.

[0036] Input device 14 is a device that accepts operations from the user. For example, input device 14 may be configured to include a keyboard, touchpad, touch panel, or mouse. In this case, if input device 14 is configured to include a touch panel, it may also serve as display device 13.

[0037] The communication device 15 is hardware used to communicate with other devices, particularly the first projector 20 and the second projector 30, and serves as a transmitting and receiving device. It may be an interface circuit or a wireless communication antenna. The communication device 15 may also be referred to as a network device, network controller, network interface card (NIC), or communication module.

[0038] The processing unit 11 reads and executes the control program PR1 from the storage device 12, thereby functioning as the first image generation unit 111, the second image generation unit 112, the first attenuation coefficient generation unit 113, the second attenuation coefficient generation unit 114, and the information output unit 115. Furthermore, the control program PR1 can also be sent from other devices such as a server managing the processing unit 11 via the communication network NET.

[0039] The first image generation unit 111 generates a first projected image projected from the first projector 20 based on the image as a whole of the objects to be projected.

[0040] The second image generation unit 112 generates a second projected image from the second projector 30 based on the image as a whole of the object being projected.

[0041] Figure 3 This diagram illustrates an example of a first display image 81 and a second display image 82 displayed on a display surface 70 by projecting a first projected image and a second projected image onto the display surface 70, respectively. Furthermore, in Figure 3 In this specification, the upper position of the first display image 81 is designated as "81TE". Similarly, the lower position of the second display image 82 is designated as "82LE". Furthermore, in this specification, the first display image 81 is sometimes simply referred to as "first image 81". Likewise, the second display image 82 is sometimes simply referred to as "second image 82".

[0042] exist Figure 3 In the example shown, the first display image 81 and the second display image 82 are arranged vertically, and the second display image 82 is located above the first display image 81. Figure 3 The positive direction of the Y-axis shown is set upwards. Hereinafter, the positive direction of the Y-axis in each figure will be set upwards. When displaying an overall image using the first display image 81 and the second display image 82, a method is considered where the overall image is displayed by making the first display image 81 and the second display image 82 adjacent to each other in the longitudinal direction without gaps. However, it is technically difficult to set the projection angle of the first projector 20 projecting the first projected image onto the display surface 70 and the projection angle of the second projector 30 projecting the second projected image onto the display surface 70 such that the first display image 81 and the second display image 82 are adjacent to each other without gaps. Therefore, as... Figure 3 As shown, the projection angles of the first and second projected images are set such that the top of the first display image 81 overlaps the bottom of the second display image 82. Based on this, a composite image 83 of the first and second display images 81 and 82 is displayed in the overlapping area 71. This composite image 83 is an image in which identical images above the first display image 81 and below the second display image 82 overlap without deviation. Using the composite image 83, the projection system 1 can display a complete image in the overlapping area 71 through multiple projections that partially overlap the first and second display images 81 and 82.

[0043] Furthermore, the position and size of the overlapping area 71 can also be calculated by the processing device 11 using layout information stored in the storage device 12 related to the configuration of the first projector 20 and the second projector 30. Alternatively, the processing device 11 can also determine the position and size of the overlapping area 71 based on the input content of the user of the projection system 1 using the input device 14.

[0044] return Figure 2To explain, the first attenuation coefficient generation unit 113 generates a first attenuation coefficient that attenuates the brightness of the first display image 81 included in the composite image 83 of the overlapping region 71 based on the position within the overlapping region 71. Specifically, the first attenuation coefficient K1 is based on... Figure 3 The coordinate y along the Y-axis is used to determine K1 = f1(y). Additionally, when the first display image 81 and the second display image 82 overlap along the X-axis, K1 = f1(x).

[0045] The second attenuation coefficient generation unit 114 generates a second attenuation coefficient that attenuates the brightness of the second display image 82 included in the composite image 83 of the overlapping region 71 based on the position within the overlapping region 71. The second attenuation coefficient K2 is based on... Figure 3 The Y-axis coordinate y is determined as shown, K2 = f2(y). Furthermore, when the first display image 81 and the second display image 82 overlap along the X-axis, K2 = f2(x).

[0046] As described above, in the overlapping region 71, when the same images overlap without deviation only above the first display image 81 and below the second display image 82, the composite image 83 is brighter than the first display image 81 and the second display image 82 displayed outside the overlapping region 71. This creates a sense of disharmony in the overall image appearance. Therefore, the projection system 1 suppresses this disharmony by attenuating the brightness of the first display image 81 and the second display image 82 within the composite image 83.

[0047] exist Figure 3 On the left side, as graphs representing the first and second attenuation coefficients, gain curves 91 and 92 are shown. Here, the "first attenuation coefficient" refers to the ratio of the brightness of the image corresponding to the overlapping region 71 in the first display image 81 to the brightness of the image corresponding to the region outside the overlapping region 71 in the first display image 81. Similarly, the "second attenuation coefficient" refers to the ratio of the brightness of the image corresponding to the overlapping region 71 in the second display image 82 to the brightness of the image corresponding to the region outside the overlapping region 71 in the second display image 82.

[0048] As shown in gain curve 91, at the upper end of the overlap region 71, i.e., at position 81TE, the upper end of the first displayed image 81, the gain of the first displayed image 81 is 0. On the other hand, at the lower end of the overlap region 71, i.e., at position 82LE, the lower end of the second displayed image 82, the gain of the first displayed image 81 is 1.0. Gain curve 91 draws an inverted S-shaped curve from the upper end of the overlap region 71 to the lower end of the overlap region 71. Similarly, at the upper end of the overlap region 71, i.e., at position 81TE, the upper end of the first displayed image 81, the gain of the second displayed image 82 is 1.0. On the other hand, at the lower end of the overlap region 71, i.e., at position 82LE, the lower end of the second displayed image 82, the gain of the second displayed image 82 is 0. Gain curve 92 draws an S-shaped curve from the upper end of the overlap region 71 to the lower end of the overlap region 71.

[0049] Therefore, regardless of the location within the overlapping region 71, the combined gain of the first displayed image 81 and the second displayed image 82 remains a constant value of 1. As a result, uneven brightness within the overlapping region 71 is suppressed, thereby reducing the overall visual disharmony of the image.

[0050] Alternatively, the first attenuation coefficient generation unit 113 can generate a first attenuation coefficient based on the input content entered by the user of the projection system 1 using the input device 14. Similarly, the second attenuation coefficient generation unit 114 can generate a second attenuation coefficient based on the input content entered by the user of the projection system 1 using the input device 14. Alternatively, the first attenuation coefficient generation unit 113 can also generate a first attenuation coefficient based on an image of the display surface 70 captured by an imaging device (not shown) included in the control device 10. Similarly, the second attenuation coefficient generation unit 114 can also generate a second attenuation coefficient based on an image of the display surface 70 captured by an imaging device (not shown) included in the control device 10.

[0051] return Figure 2 To illustrate, the information output unit 115 uses the communication device 15 to output a first display image 81 and a first attenuation coefficient to the first projector 20. Similarly, the information output unit 115 uses the communication device 15 to output a second display image 82 and a second attenuation coefficient to the second projector 30. Furthermore, the information output unit 115 can also use the communication device 15 to output layout information stored in the storage device 12 to the first projector 20 and the second projector 30.

[0052] 1-3. Structure of the first projector 20

[0053] Figure 4This is a block diagram illustrating a structural example of a first projector 20. The first projector 20 includes a sensor 21, a projection device 22, a processing device 23, a storage device 24, and a communication device 25. The various components of the first projector 20 are interconnected via one or more individual buses for communicating information.

[0054] Sensor 21 is an inertial sensor that detects the vibration of the first projector 20. Sensor 21 may be, for example, an accelerometer, a gyroscope, or a combination of both. Sensor 21 is disposed inside a housing (not shown) of the first projector 20 and fixed to the first projector 20, thus enabling it to detect the vibration of the first projector 20.

[0055] The projection device 22 is a device that projects a first projected image output from the first attenuation unit 232 (described later) onto a screen or wall, etc. The screen or wall is an example of the display surface 70. The projection device 22 projects various images under the control of the processing device 23. The projection device 22 includes, for example, a light source, a liquid crystal panel, and a projection lens. The liquid crystal panel modulates the light from the light source, and the modulated light is projected onto the screen or wall, etc., via the projection lens.

[0056] The processing device 23 is a processor that controls the first projector 20 as a whole, and may be composed of one or more chips. The processing device 23 may consist, for example, a central processing unit (CPU) that includes interfaces with peripheral devices, arithmetic units, and registers. Alternatively, some or all of the functions of the processing device 23 may be implemented using hardware such as DSPs, ASICs, PLDs, and FPGAs. The processing device 23 executes various processes in parallel or sequentially.

[0057] Storage device 24 is a recording medium that can be read by processing device 23, storing multiple programs including control program PR2 executed by processing device 23. Additionally, storage device 24 stores the first projected image and the first attenuation coefficient obtained using communication device 25 (described later). Furthermore, storage device 24 may also store layout information related to the configuration of the first projector 20 and the second projector 30. Storage device 24 may be composed of at least one of ROM, EPROM, EEPROM, RAM, etc. Storage device 24 may also be referred to as a register, cache, main memory, or main storage device, etc.

[0058] The communication device 25 is hardware used for communicating with other devices, especially the control device 10, as a transceiver, such as an interface circuit or a wireless communication antenna. The communication device 25 is also referred to as a network device, network controller, network interface card (NIC), or communication module.

[0059] The processing unit 23 reads and executes the control program PR2 from the storage device 24, and functions as an overlay unit 231, a first attenuation unit 232, a calculation unit 233, an image movement unit 234, a correction unit 235, a speed-up readout unit 236, and an image output unit 237. Furthermore, the control program PR2 can also be sent from other devices, such as a server managing the processing unit 23, via the communication network NET.

[0060] The overlay unit 231 initially reads the first projected image from the storage device 24. Then, the overlay unit 231 performs overlay processing on the first projected image to create an overlay image. Here, the overlay image refers to an OSD (On Screen Display) based overlay image.

[0061] The first attenuation unit 232 first reads the first attenuation coefficient from the storage device 24. Additionally, the first attenuation unit 232 sometimes uses the first attenuation coefficient to attenuate the brightness of the portion of the first projected image corresponding to the overlapping region 71 in the first displayed image 81, based on its position within the overlapping region 71. Finally, the first attenuation unit 232 saves the first projected image, after attenuating the brightness of the portion corresponding to the overlapping region 71, in the storage device 24.

[0062] The calculation unit 233 calculates displacement information related to the position of the first projector 20 based on the output signal from the sensor 21. Here, "displacement information" includes displacement amount, which represents the magnitude of the displacement of the first projector 20, and displacement direction, which represents the direction of the displacement of the first projector 20.

[0063] For example, if sensor 21 is an accelerometer, assuming the first projector 20 is positioned in a three-dimensional space (x, y, z), the calculation unit 233 can calculate the displacement related to the position of the first projector 20 by integrating the acceleration values ​​of the x, y, and z axes detected by sensor 21 twice over time. Alternatively, if sensor 21 is a gyroscope, assuming the attitude of the first projector 20 is defined by the orthogonal axes of the roll, pitch, and yaw axes, the calculation unit 233 can calculate the displacement related to the attitude of the first projector 20 by integrating the angular velocities around the roll, pitch, and yaw axes detected by sensor 21 once over time.

[0064] When the position of the first projector 20 is displaced from the reference position, the image moving unit 234 moves the first projected image within the liquid crystal panel on the display surface 70 in such a way that the first displayed image 81 moves in the opposite direction to the displacement direction according to the amount of displacement. Here, the "reference position" refers to the position of the first projector 20 when it is not vibrating.

[0065] During the process of projecting the first projected image onto the display surface 70 via the first projector 20, thereby displaying the first display image 81 on the display surface 70, when the first projector 20 vibrates, the first display image 81 also vibrates accordingly. As a result, a misalignment occurs between the first display image 81 and the second display image 82 on the display surface 70. Therefore, due to the multiple projections of the first display image 81 and the second display image 82, a sense of disharmony arises in the overall appearance of the image displayed on the display surface 70.

[0066] Therefore, in addition to using the calculated displacement of the first projector 20, the image moving unit 234 also uses the distance between the first projector 20 and the display surface 70, the positional relationship between the optical axis of the first projector 20 and the display surface 70, etc., to calculate the deviation of the first displayed image 81. Furthermore, the image moving unit 234 moves the first projected image within the liquid crystal panel by this deviation, moving the first displayed image 81 in a direction opposite to the displacement direction of the first projector 20. In other words, the image moving unit 234 moves the first projected image within the liquid crystal panel by this deviation, in a manner close to the position of the first displayed image 81 displayed when the first projector 20 is not vibrating.

[0067] The correction unit 235 corrects the first attenuation coefficient based on the displacement information. Figures 5-7 This is an explanatory diagram of the correction method for the first attenuation coefficient performed by the correction unit 235.

[0068] exist Figure 5 In the diagram, the upper end of the first displayed image 81 when it jitters upward is indicated by "81UTE". The original position of the upper end of the first displayed image 81 is indicated by "81TE". The lower end of the second displayed image 82 is indicated by "82LE". In the display surface 70, when the first displayed image 81 jitters upward due to the vibration of the first projector 20, the image moving unit 234 moves the first projected image within the liquid crystal panel, causing the first displayed image 81 to deviate downward. As a result, as... Figure 5 As shown on the right, the moved first display image 84 is displayed in approximately the same position as the original first display image 81. However, since the projection area of ​​the first projector 20 remains in an upward-tilting position, as... Figure 5 As shown, the upper end of the first display image 84 coincides with the upper end 81UTE of the projection area after upward jitter. As a result, a new overlapping area 73 is added to the original overlapping area 71 of the first display image 81 and the second display image 82. In this new overlapping area 73, the first display image 81 is newly superimposed on the second display image 82, therefore the overlapping area 73 is brighter than the overlapping area 71. Thus, as... Figure 5As shown in the right figure, the correction unit 235 sets the gain of the portion of the first display image 81 corresponding to the overlapping region 73 to 0 and blacks it out. Therefore, the combined gain of the first display image 81 and the second display image 82 in the overlapping region 73 becomes 1.0 at any point within the overlapping region 73.

[0069] exist Figure 6 In the original position of the upper part of the first displayed image 81, it is indicated as "81TE". Furthermore, the upper part of the first displayed image 81 when it is jittered downwards is indicated as "81LTE". Additionally, the lower part of the second displayed image 82 is indicated as "82LE". Furthermore, in... Figure 7 In the diagram, the original position of the upper end of the first displayed image 81 is designated as "81TE". Furthermore, the upper end of the first displayed image 81 when it is jittering downwards is designated as "81LTE". The lower end of the second displayed image 82 is designated as "82LE". In the display surface 70, when the first displayed image 81 jitters downwards due to the vibration of the first projector 20, the image moving unit 234 moves the first projected image within the liquid crystal panel, causing the first displayed image 81 to deflect upwards within the display surface 70. However, along with the downward jittering of the first displayed image 81, as... Figure 6 As shown, gain curve 91 also shifts downwards, i.e., in a negative direction on the Y-axis, as shown by gain curve 93. As a result, in the new overlap region 74, the combined gain of the first display image 81 and the second display image 82 no longer remains 1.0. Therefore, as... Figure 7 As shown, the correction unit 235 shifts the gain curve 94 of the portion of the gain curve 93 corresponding to the new overlapping region 74 upward by the same amount that the gain curve 91 shifts downward. As a result, in the new overlapping region 74, the combined gain of the first display image 81 and the second display image 82 remains at 1.0.

[0070] After the correction unit 235 corrects the first attenuation coefficient, the first attenuation unit 232 uses a new attenuation coefficient to attenuate the brightness of the portion of the first projected image corresponding to the new overlapping region 74 in the first displayed image 81, based on the position within the new overlapping region 74. Furthermore, the first attenuation unit 232 saves the first projected image with the attenuated brightness of the portion corresponding to the new overlapping region 74 in the storage device 24.

[0071] The speed-up readout unit 236 reads the first projected image written to the storage device 24 at a speed higher than the write speed. The first projected image read by the speed-up readout unit 236 is output to the image output unit 237.

[0072] The image output unit 237 outputs the first projected image read by the speed-up readout unit 236 to the projection device 22.

[0073] 1-4. Structure of the second projector 30

[0074] Figure 8 This is a block diagram illustrating a structural example of a second projector 30. The second projector 30 includes a projection device 32, a processing device 33, a storage device 34, and a communication device 35. The various components of the second projector 30 are interconnected via one or more individual buses for communicating information.

[0075] The projection device 32 is a device that projects a second projected image output from the image output unit 334 (described later) onto a screen or wall, etc. The screen or wall is an example of the display surface 70. The projection device 32 projects various images under the control of the processing unit 33. The projection device 32 includes, for example, a light source, a liquid crystal panel, and a projection lens. The liquid crystal panel modulates the light from the light source, and the modulated light is projected onto the screen or wall, etc., via the projection lens.

[0076] The processing device 33 is a processor that controls the second projector 30 as a whole, and may be composed of one or more chips. The processing device 33 may consist, for example, a central processing unit (CPU) that includes interfaces with peripheral devices, arithmetic units, and registers. Alternatively, some or all of the functions of the processing device 33 may be implemented using hardware such as DSPs, ASICs, PLDs, and FPGAs. The processing device 33 executes various processes in parallel or sequentially.

[0077] Storage device 34 is a recording medium that can be read by processing device 33, storing multiple programs including control program PR3 executed by processing device 33. Additionally, storage device 34 stores a second projected image and a second attenuation coefficient obtained using communication device 35 (described later). Furthermore, storage device 34 may also store layout information related to the configuration of the first projector 20 and the second projector 30. Storage device 34 may be composed of at least one of ROM, EPROM, EEPROM, RAM, etc. Storage device 34 may also be referred to as a register, cache, main memory, or main storage device, etc.

[0078] The communication device 35 is hardware used for communicating with other devices, especially the control device 10, as a transceiver, such as an interface circuit or a wireless communication antenna. The communication device 35 is also referred to as a network device, network controller, network interface card (NIC), or communication module.

[0079] The processing unit 33 reads and executes the control program PR3 from the storage device 34, and functions as the overlay unit 331, the second attenuation unit 332, the speed-up readout unit 333, and the image output unit 334. Alternatively, the control program PR3 can also be sent via the communication network NET from other devices such as a server that manages the second projector 30.

[0080] The overlay unit 331 initially reads the second projected image from the storage device 34. Then, the overlay unit 331 performs a process of overlaying the second projected image with an overlapping image. Here, the overlapping image is an OSD (On Screen Display) based overlapping image.

[0081] The second attenuation unit 332 first reads the second attenuation coefficient from the storage device 34. Additionally, the second attenuation unit 332 sometimes uses the second attenuation coefficient to attenuate the brightness of the portion of the second projected image corresponding to the overlapping region 71 in the second displayed image 82, based on its position within the overlapping region 71. Finally, the second attenuation unit 332 outputs the second projected image, after attenuating the brightness of the portion corresponding to the overlapping region 71, to the projection device 32.

[0082] The speed-up readout unit 333 reads the second projected image written to the storage device 34 at a speed higher than the write speed. The second projected image read by the speed-up readout unit 333 is output to the image output unit 334.

[0083] The image output unit 334 outputs the second projected image read by the speed-up readout unit 333 to the projection device 32.

[0084] 1-5. Operation of the first embodiment

[0085] Next, the operation of projection system 1 will be explained. Figure 9 This is a timing diagram representing an example of the operation of projection system 1.

[0086] In step Sa1, the processing unit 11 of the control device 10 functions as a first image generation unit 111, thereby generating a first projected image. Additionally, the processing unit 11 of the control device 10 functions as an information output unit 115, thereby outputting the generated first projected image to the first projector 20.

[0087] In step Sa2, the processing unit 11 of the control device 10 functions as a second image generation unit 112, thereby generating a second projected image. Additionally, the processing unit 11 of the control device 10 functions as an information output unit 115, thereby outputting the generated second projected image to the second projector 30.

[0088] In step Sa3, the processing unit 11 of the control device 10 functions as a first attenuation coefficient generation unit 113, thereby generating a first attenuation coefficient. Additionally, the processing unit 11 of the control device 10 functions as an information output unit 115, thereby outputting the generated first attenuation coefficient to the first projector 20.

[0089] In step Sb1, the processing unit 23 of the first projector 20 functions as a first attenuation unit 232, thereby using a first attenuation coefficient to attenuate the brightness of the portion of the first projected image corresponding to the overlapping region 71 in the first display image 81 according to its position within the overlapping region 71. Furthermore, by functioning as the first attenuation unit 232, the processing unit 23 stores the first projected image with the attenuated brightness of the portion corresponding to the overlapping region 71 in the storage device 24. Additionally, the processing unit 23 functions as a speed-up readout unit 236, thereby reading the first projected image written to the storage device 24 at a speed higher than the write speed. Furthermore, by functioning as an image output unit 237, the processing unit 23 outputs the first projected image read out by the speed-up readout unit 236 to the projection device 22. As a result, the first display image 81 is displayed on the display surface 70.

[0090] In step Sa4, the processing unit 11 of the control device 10 functions as a second attenuation coefficient generation unit 114, thereby generating a second attenuation coefficient. Additionally, the processing unit 11 of the control device 10 functions as an information output unit 115, thereby outputting the generated second attenuation coefficient to the second projector 30.

[0091] In step Sc1, the processing unit 33 of the second projector 30 functions as a second attenuation unit 332, thereby using a second attenuation coefficient to attenuate the brightness of the portion of the second projected image corresponding to the overlapping region 71 in the second display image 82 according to its position within the overlapping region 71. Furthermore, by functioning as the second attenuation unit 332, the processing unit 33 stores the second projected image with the attenuated brightness of the portion corresponding to the overlapping region 71 in the storage device 34. Additionally, the processing unit 33 functions as a speed-up readout unit 333, thereby reading the second projected image written to the storage device 34 at a speed higher than the write speed. Furthermore, the processing unit 33 functions as an image output unit 334, thereby outputting the second projected image read out by the speed-up readout unit 333 to the projection device 32. As a result, the second display image 82 is displayed on the display surface 70.

[0092] In step Sb2, the processing device 23 of the first projector 20 functions as a calculation unit 233, thereby calculating displacement information related to the position of the first projector 20 based on the output signal from the sensor 21.

[0093] In step Sb3, the processing device 23 of the first projector 20 functions as an image moving unit 234, thereby moving the first projected image within the liquid crystal panel when the position of the first projector 20 is displaced from the reference position. As a result, on the display surface 70, the first displayed image 81 moves in the opposite direction to the displacement direction according to the amount of displacement.

[0094] In step Sb4, the processing device 23 of the first projector 20 functions as a correction unit 235, thereby correcting the first attenuation coefficient based on the displacement information.

[0095] In step Sb5, the processing unit 23 of the first projector 20 functions as a first attenuation unit 232, thereby using a corrected first attenuation coefficient to attenuate the brightness of the portion of the first projected image corresponding to the new overlapping area in the first display image 81 according to its position within the new overlapping area. Furthermore, by functioning as the first attenuation unit 232, the processing unit 23 stores the first projected image with the attenuated brightness of the portion corresponding to the new overlapping area in the storage device 24. Additionally, the processing unit 23 functions as a speed-up readout unit 236, thereby reading the first projected image written to the storage device 24 at a speed higher than the write speed. Furthermore, by functioning as an image output unit 237, the processing unit 23 outputs the first projected image read out by the speed-up readout unit 236 to the projection device 22. As a result, a new first display image 84 is displayed on the display surface 70.

[0096] 1-6. Effects of the first implementation method

[0097] In the image display method of this embodiment, when the position of the first projector 20 is a reference position, the first attenuation unit 232 attenuates the brightness of the image in the first display image 81 corresponding to the overlapping region 71 where the first display image 81 and the second display image 82 displayed by the second projector 30 overlap in the display surface 70, based on a first attenuation coefficient determined according to the position within the overlapping region 71. Next, when the position of the first projector 20 shifts from the reference position, the correction unit 235 corrects the first attenuation coefficient based on displacement information related to the displacement of the first projector 20 calculated based on the output signal of the sensor 21. Finally, when the position of the first projector 20 shifts from the reference position, the first attenuation unit 232 attenuates the brightness of the image in the first display image 81 corresponding to the overlapping region 71, overlapping region 73, or overlapping region 74, based on the corrected first attenuation coefficient.

[0098] According to this structure, even if vibration occurs in the first projector 20, the display quality of the displayed image in the overlapping regions 71, 73, or 74 can be prevented from deteriorating, and unnatural appearance can be suppressed. In particular, by using a first attenuation coefficient corrected according to the jitter, uneven brightness generated in the overlapping regions 71, 73, or 74 can be suppressed.

[0099] In addition, the displacement information includes a displacement amount, which indicates the magnitude of the displacement of the first projector 20, and a displacement direction, which indicates the direction of the displacement of the first projector 20. When the position of the first projector 20 is displaced from the reference position, the image moving unit 234 moves the first display image 81 in the opposite direction to the displacement direction according to the displacement amount.

[0100] According to this structure, it is possible to perform correction of the jitter of the first displayed image 81 caused by the vibration of the first projector 20 body.

[0101] Furthermore, the first attenuation coefficient is the ratio of the brightness of the image corresponding to the overlapping region 71 in the first display image 81 to the brightness of the image corresponding to the region outside the overlapping region 71 in the first display image 81. The second attenuation coefficient is the ratio of the brightness of the image corresponding to the overlapping region 71 in the second display image 82 to the brightness of the image corresponding to the region outside the overlapping region 71 in the second display image 82. The sum of the first attenuation coefficient and the second attenuation coefficient is 1.

[0102] By maintaining the sum of the first and second attenuation coefficients in the overlapping region 71 at 1, the unevenness of the image brightness in the overlapping region 71 is suppressed.

[0103] In the first projector 20 of this embodiment, when the position of the first projector 20 is a reference position, the first attenuation unit 232 attenuates the brightness of the image in the first display image 81 corresponding to the overlapping region 71 where the first display image 81 and the second display image 82 displayed by the second projector 30 overlap on the display surface 70, based on a first attenuation coefficient determined according to the position within the overlapping region 71. Next, when the position of the first projector 20 shifts from the reference position, the correction unit 235 corrects the first attenuation coefficient based on displacement information related to the displacement of the first projector 20 calculated based on the output signal of the sensor 21. Finally, when the position of the first projector 20 shifts from the reference position, the first attenuation unit 232 attenuates the brightness of the image in the first display image 81 corresponding to the overlapping region 71, overlapping region 73, or overlapping region 74, based on the corrected first attenuation coefficient.

[0104] According to this structure, even if vibration occurs in the first projector 20, the display quality of the displayed image in the overlapping regions 71, 73, or 74 can be prevented from deteriorating, and unnatural appearance can be suppressed. In particular, by using a first attenuation coefficient corrected according to the jitter, uneven brightness generated in the overlapping regions 71, 73, or 74 can be suppressed.

[0105] The projection system 1 of this embodiment includes: a first projector 20 that displays a first display image 81 on a display surface 70; and a second projector 30 that displays a second display image 82 on the display surface 70. In the first projector 20, when the position of the first projector 20 is a reference position, a first attenuation unit 232 attenuates the brightness of the image corresponding to the overlapping region 71 of the first display image 81 that overlaps with the first display image 81 and the second display image 82 on the display surface 70, based on a first attenuation coefficient determined according to the position within the overlapping region 71. Next, when the position of the first projector 20 shifts from the reference position, a correction unit 235 corrects the first attenuation coefficient based on displacement information related to the displacement of the first projector 20 calculated based on the output signal of the sensor 21. Finally, when the position of the first projector 20 shifts from the reference position, the first attenuation unit 232 attenuates the brightness of the image corresponding to the overlapping region 71, overlapping region 73, or overlapping region 74 of the first display image 81 based on the corrected first attenuation coefficient.

[0106] According to this structure, even if vibration occurs in the first projector 20, the display quality of the displayed image in the overlapping regions 71, 73, or 74 can be prevented from deteriorating, and unnatural appearance can be suppressed. In particular, by using a first attenuation coefficient corrected according to the jitter, uneven brightness generated in the overlapping regions 71, 73, or 74 can be suppressed.

[0107] 2. Second Implementation Method

[0108] 2-1. Overall Structure

[0109] Figure 10 This is a schematic diagram showing the overall structure of the projection system 1A according to the second embodiment. The projection system 1A includes a control device 10 and a first projector 20A, a second projector 30A, a third projector 40A, and a fourth projector 50A, which are multiple projectors. Furthermore, for the sake of simplicity, in... Figure 10In the example shown, the projection system 1A has a first projector 20A, a second projector 30A, a third projector 40A, and a fourth projector 50A as four projectors. However, the number of projectors in the projection system 1A is not limited to four; it can also have two, three, or five or more projectors.

[0110] like Figure 10 As shown, the first projector 20A to the fourth projector 50A are connected in a manner that enables them to communicate with each other via a connecting cable 60. By connecting the first projector 20A to the fourth projector 50A in a manner that enables them to communicate with each other, as described later, position information related to the position of the overlapping area is sent from the first projector 20A to the other projectors. Here, "position information" refers to the two-dimensional position information of the overlapping area 71 in the display surface 70. This position information is, for example, generated by... Figure 3 The (x, y) coordinates in the XY coordinate system are shown.

[0111] In addition, Figure 10 In the example shown, the first projector 20A to the fourth projector 50A are connected in a daisy chain, i.e., a loop, via connecting cable 60. However, the connection method of the first projector 20A to the fourth projector 50A in this embodiment is not limited to a daisy chain. The style is not limited as long as the connection method involves the first projector 20A sending position information related to the position of the overlapping area to the other projectors.

[0112] 2-2. Structure of the first projector 20A

[0113] Figure 11 This is a block diagram illustrating a structural example of the first projector 20A. Furthermore, for the sake of simplicity, components of the first projector 20A in this embodiment that are identical to those of the first projector 20 in the first embodiment will be indicated using the same reference numerals, and their functions will be omitted. Hereinafter, the differences between the first projector 20A and the first projector 20 will be primarily described.

[0114] The first projector 20A differs from the first projector 20 in that it has a processing unit 23A instead of a processing unit 23. The processing unit 23A has a calculation unit 233A instead of a calculation unit 233. In addition to the components of the processing unit 23, the processing unit 23A also has an information output unit 238.

[0115] The calculation unit 233A calculates displacement information related to the position of the first projector 20A based on the output signal from the sensor 21. In addition, the calculation unit 233A uses the calculated displacement information and layout information stored in the storage device 24 to calculate the position information of the overlapping area 71 in the display surface 70.

[0116] The information output unit 238 uses the communication device 25 to output the position information calculated by the calculation unit 233A to the second projector 30A to the fourth projector 50A.

[0117] 2-3. Composition of the second projector 30A

[0118] Figure 12 This is a block diagram illustrating a structural example of the second projector 30A. Furthermore, for the sake of simplicity, components of the second projector 30A in this embodiment that are identical to those in the second projector 30 of the first embodiment will be indicated by the same reference numerals, and their functions will be omitted. Hereinafter, the differences between the second projector 30A and the second projector 30 will be primarily described. Additionally, the structures of the third projector 40A and the fourth projector 50A are similar to... Figure 12 The second projector 30A shown has the same structure, so its illustration and description are omitted.

[0119] The second projector 30A differs from the second projector 30 in that it has a processing unit 33A instead of the processing unit 33. In addition to the components of the processing unit 33, the processing unit 33A also has an information acquisition unit 335 and a correction unit 336.

[0120] The information acquisition unit 335 uses the communication device 35 to acquire location information from the first projector 20A.

[0121] The correction unit 336 uses the position information obtained by the information acquisition 335 to correct the second attenuation coefficient. Figure 13 This is an explanatory diagram regarding the correction method for the second attenuation coefficient performed by the correction unit 336. Furthermore, in Figure 13 In the above, the original position of the upper part of the first display image 81 is indicated as "81TE". Additionally, the upper part of the first display image 81 when it is jittered downwards is indicated as "81LTE". Furthermore, the lower part of the second display image 82 is indicated as "82LE".

[0122] Here, refer to Figure 7 In the projection system 1 of the first embodiment, when the first displayed image 81 jitters downwards, the correction unit 235 corrects the first attenuation coefficient, but the second attenuation coefficient is not corrected. Therefore, as Figure 7As shown, in region 75, with the original position 81TE at the top of the first displayed image 81 as the upper end and the position 81LTE at the top when the first displayed image 81 is jittered downwards as the lower end, the gain of the second displayed image 82 is plotted as a curve from 1.0x to 0.5x. When the first displayed image 81 jitters downwards, the first displayed image 81 is not present in region 75; only the second displayed image 82, whose gain changes from 1.0x to 0.5x, exists. Therefore, the brightness of region 75 is reduced compared to other regions. Therefore, as... Figure 13 As shown, the correction unit 336 eliminates edge blending in region 75 by correcting the second attenuation coefficient. Therefore, the gain curve 95 depicted by the corrected second attenuation coefficient becomes a straight line 95A in region 75 that does not change by a factor of 1.0. On the other hand, in the overlapping region 74 where the upper end 81LTE of the first display image 81 is dithered downwards and the lower end 82LE of the second display image 82 is dithered downwards, the gain curve 95 becomes a curved section 95B that curves from 0.5 to 0. Therefore, in the entire display area of ​​the first display image 81 and the second display image 82, the total gain of the first display image 81 and the second display image 82 remains 1.0. Furthermore, the value of "0.5" here is just one example of the gain value and is not limited to it; any value between 0 and 1 is acceptable.

[0123] 2-4. Operation of the Second Embodiment

[0124] Next, the operation of the projection system 1A will be explained. Figure 14 This is a timing diagram illustrating an example of the operation of projection system 1A. Additionally, in Figure 14 For the sake of simplicity, the description of the operation of the third projector 40A and the fourth projector 50A is omitted. The operation of the third projector 40A and the fourth projector 50A is basically the same as that of the second projector 30A. In addition, in the embodiments illustrated below, for elements that have the same function or effect as those in the first embodiment, the reference numerals used in the description of the first embodiment are retained, and their detailed descriptions are appropriately omitted.

[0125] In step Sa11, the processing unit 11 of the control device 10 functions as a first image generation unit 111, thereby generating a first projected image. Additionally, the processing unit 11 of the control device 10 functions as an information output unit 115, thereby outputting the generated first projected image to the first projector 20A.

[0126] In step Sa12, the processing unit 11 of the control device 10 functions as a second image generation unit 112, thereby generating a second projected image. Additionally, the processing unit 11 of the control device 10 functions as an information output unit 115, thereby outputting the generated second projected image to the second projector 30A.

[0127] In step Sa13, the processing unit 11 of the control device 10 functions as a first attenuation coefficient generation unit 113, thereby generating a first attenuation coefficient. Additionally, the processing unit 11 of the control device 10 functions as an information output unit 115, thereby outputting the generated first attenuation coefficient to the first projector 20A.

[0128] In step Sb11, the processing device 23A of the first projector 20A functions as a first attenuation unit 232, thereby using a first attenuation coefficient to attenuate the brightness of the portion of the first projected image corresponding to the overlapping region 71 in the first display image 81 according to its position within the overlapping region 71. Furthermore, by functioning as the first attenuation unit 232, the processing device 23A stores the first projected image with the attenuated brightness of the portion corresponding to the overlapping region 71 in the storage device 24. Additionally, the processing device 23A functions as a speed-up readout unit 236, thereby reading the first projected image written to the storage device 24 at a speed higher than the write speed. Furthermore, by functioning as an image output unit 237, the processing device 23A outputs the first projected image read out by the speed-up readout unit 236 to the projection device 22. As a result, the first display image 81 is displayed on the display surface 70.

[0129] In step Sa14, the processing unit 11 of the control device 10 functions as a second attenuation coefficient generation unit 114, thereby generating a second attenuation coefficient. Additionally, the processing unit 11 of the control device 10 functions as an information output unit 115, thereby outputting the generated second attenuation coefficient to the second projector 30A.

[0130] In step Sc11, the processing device 33A of the second projector 30A functions as a second attenuation unit 332, thereby using a second attenuation coefficient to attenuate the brightness of the portion of the second projected image corresponding to the overlapping region 71 in the second display image 82 according to its position within the overlapping region 71. Furthermore, by functioning as the second attenuation unit 332, the processing device 33A stores the second projected image with the attenuated brightness of the portion corresponding to the overlapping region 71 in the storage device 34. Additionally, the processing device 33A functions as a speed-up readout unit 333, thereby reading the second projected image written to the storage device 34 at a speed higher than the write speed. Furthermore, by functioning as an image output unit 334, the processing device 33A outputs the second projected image read out by the speed-up readout unit 333 to the projection device 32. As a result, the second display image 82 is displayed on the display surface 70.

[0131] In step Sb12, the processing unit 23A of the first projector 20A functions as a calculation unit 233A, thereby calculating displacement information related to the position of the first projector 20A based on the output signal from the sensor 21. Furthermore, by functioning as a calculation unit 233A, the processing unit 23A uses the calculated displacement information and the layout information stored in the storage device 24 to calculate the position information of the overlapping area 71 in the display surface 70.

[0132] In step Sb13, the processing device 23A of the first projector 20A functions as an information output unit 238, thereby using the communication device 25 to output the position information calculated by the calculation unit 233A to the second projector 30A.

[0133] In step Sb14, the processing device 23A of the first projector 20A functions as an image moving unit 234, thereby moving the first projected image within the liquid crystal panel. As a result, when the position of the first projector 20A is displaced from the reference position, the first displayed image 81 on the display surface 70 moves in the opposite direction to the displacement direction according to the displacement amount.

[0134] In step Sb15, the processing device 23A of the first projector 20A functions as a correction unit 235, thereby correcting the first attenuation coefficient based on the displacement information.

[0135] In step Sb16, the processing device 23A of the first projector 20A functions as a first attenuation unit 232, thereby using a corrected first attenuation coefficient to attenuate the brightness of the portion of the first projected image corresponding to the new overlapping area in the first display image 81 according to its position within the new overlapping area. Furthermore, by functioning as the first attenuation unit 232, the processing device 23A stores the first projected image with the attenuated brightness of the portion corresponding to the new overlapping area in the storage device 24. Additionally, the processing device 23A functions as a speed-up readout unit 236, thereby reading the first projected image written to the storage device 24 at a speed higher than the write speed. Furthermore, by functioning as an image output unit 237, the processing device 23A outputs the first projected image read out by the speed-up readout unit 236 to the projection device 22. As a result, a new first display image 84 is displayed on the display surface 70.

[0136] In step Sc12, the processing device 33A of the second projector 30A functions as a correction unit 336, thereby correcting the second attenuation coefficient based on the position information.

[0137] In step Sc13, the processing device 33A of the second projector 30A functions as a second attenuation unit 332. Thereby, using a corrected second attenuation coefficient, the brightness of the image corresponding to the original overlapping area in the second display image 82 is maintained or attenuated based on its position within the original overlapping area. Furthermore, by functioning as the second attenuation unit 332, the processing device 33A stores the second projected image with the brightness of the image corresponding to the original overlapping area changed in the storage device 34. Additionally, the processing device 33A functions as a speed-up readout unit 333, thereby reading the new second projected image written to the storage device 34 at a speed higher than the write speed. Furthermore, by functioning as an image output unit 334, the processing device 33A outputs the second projected image read out by the speed-up readout unit 333 to the projection device 32. As a result, a new second display image 85 is displayed on the display surface 70.

[0138] 2-5. Effects of the second implementation method

[0139] In the image display method of this embodiment, the calculation unit 233A calculates position information related to the position of the overlapping area 71 on the display surface 70 based on the displacement information of the first projector 20A. Based on this, the information output unit 238 sends the calculated position information to the second projector 30A. The correction unit 336 of the second projector 30A uses the position information obtained from the first projector 20A to correct the second attenuation coefficient.

[0140] When the first displayed image 81 is jittering downwards, for example, if the brightness of the first displayed image 81 is adjusted only by shifting the gain curve of the first displayed image 81, a portion of the total gain of the first displayed image 81 and the second displayed image 82 will be inconsistent. Therefore, the information output unit 238 sends the aforementioned position information to the second projector 30A, and on the second projector 30A side, the total gain can also be kept constant by adjusting the gain curve of the second displayed image 82.

[0141] The projection system 1A of this embodiment includes: a first projector 20A that displays a first display image 81 on a display surface 70; and a second projector 30A that displays a second display image 82 on the display surface 70. In the first projector 20A, when the position of the first projector 20A is a reference position, a first attenuation unit 232 attenuates the brightness of the image corresponding to the overlapping region 71 of the first display image 81 that overlaps with the first display image 81 and the second display image 82 on the display surface 70, based on a first attenuation coefficient determined according to the position within the overlapping region 71. Next, when the position of the first projector 20A shifts from the reference position, a calculation unit 233A calculates position information related to the position of the overlapping region 71 on the display surface 70 based on displacement information related to the displacement of the first projector 20A calculated based on the output signal of the sensor 21. Then, an information output unit 238 outputs the position information to the second projector 30A. Next, a correction unit 235 corrects the first attenuation coefficient based on the displacement information. Next, when the position of the first projector 20A shifts from the reference position, the first attenuation unit 232 attenuates the brightness of the image corresponding to the overlapping region 71, overlapping region 73, or overlapping region 74 in the first displayed image 81 based on the corrected first attenuation coefficient. In the second projector 30A, the second attenuation unit 332 attenuates the brightness of the image corresponding to the overlapping region 71, overlapping region 73, or overlapping region 74 in the second displayed image 82 based on the second attenuation coefficient determined according to the position within the overlapping region 71, overlapping region 73, or overlapping region 74. Next, the information acquisition unit 335 acquires position information. Then, the correction unit 336 corrects the second attenuation coefficient based on the position information. Finally, the second attenuation unit 332 attenuates the brightness of the second displayed image 82 based on the corrected second attenuation coefficient.

[0142] When the first displayed image 81 is jittering downwards, for example, if the brightness of the first displayed image 81 is adjusted only by shifting the gain curve of the first displayed image 81, a portion of the total gain of the first displayed image 81 and the second displayed image 82 will be inconsistent. Therefore, the information output unit 238 sends the aforementioned position information to the second projector 30A, and on the second projector 30A side, the total gain can also be kept constant by adjusting the gain curve of the second displayed image 82.

[0143] 3. Variations

[0144] This disclosure is not limited to the embodiments illustrated above. Specific variations are illustrated below. Two or more embodiments selected from the following examples may also be combined.

[0145] 3-1. Variation Example 1

[0146] In the projection systems 1 and 1A of the first and second embodiments described above, the control device 10 is separate from the first projector 20 or 20A and the second projector 30 or 30A. However, by incorporating the first projector 20 or 20A into the control device 10, this embodiment can also be configured such that the control device 10 and the first projector 20 or 20A operate within the same housing. Similarly, by incorporating the second projector 30 or 30A into the control device 10, this embodiment can also be configured such that the control device 10 and the second projector 30 or 30A operate within the same housing. Furthermore, the first projector 20 or 20A and the second projector 30 or 30A can also incorporate only a portion of the components of the control device 10 as their own components. For example, the first projector 20 or 20A can also incorporate only the first attenuation coefficient generating unit 113 from the components of the control device 10 as its own component. Similarly, the second projector 30 or 30A may also incorporate only the second attenuation coefficient generating unit 114, which is a component of the control device 10, as its own component.

[0147] 3-2. Variation Example 2

[0148] In the first embodiment, the second projector 30 differs from the first projector 20 in that it does not have the sensor 21 and the image movement unit 234, but it may have corresponding components. Therefore, the second projector 30 can also correct the positional deviation of the second displayed image 82 on the display surface 70 by independently correcting the position of the second projected image within the liquid crystal panel.

[0149] 3-3. Variation Example 3

[0150] In the second embodiment, only the first projector 20A includes the sensor 21, the calculation unit 233A, the image movement unit 234, and the information output unit 238, and only the second projector 30A includes the information acquisition unit 335. However, it is also possible that the first projector 20A includes components corresponding to the information acquisition unit 335, and the second projector 30A includes components corresponding to the sensor 21, the calculation unit 233A, the image movement unit 234, and the information output unit 238. That is, the first projector 20A and the second projector 30A may have the same structure.

[0151] 3-4. Variation Example 4

[0152] In the first and second embodiments, the first attenuation unit 232 writes the first projected image to the storage device 24, and the speed-up readout unit 236 reads the first projected image written to the storage device 24. Similarly, the second attenuation unit 332 writes the second projected image to the storage device 34, and the speed-up readout unit 333 reads the second projected image written to the storage device 34. However, the timing of writing and reading the projected image is not limited to this. For example, the overlap unit 231 or 331 may write a projected image with an overlapped image to the storage device 24 or 34, and then the speed-up readout unit 236 or 333 may read the projected image written to the storage device 24 or 34.

[0153] 3-5. Variation Example 5

[0154] In the first and second embodiments, the first attenuation unit 232 writes the first projected image, after attenuating the brightness of the image corresponding to the overlapping region 71, to the storage device 24. Furthermore, when the position of the first projector 20 shifts from a reference position, the image movement unit 234 moves the first projected image within the liquid crystal panel, causing the first display image 81 to move on the display surface 70 in the direction opposite to the shift direction according to the displacement amount. Then, the speed-up readout unit 236 reads the first projected image written to the storage device 24. However, the processing of the first projected image in this embodiment is not limited to this. For example, after the image movement unit 234 corrects the deviation of the first display image 81, geometric correction can be performed on the first projected image. Here, "geometric correction" refers to a technique that pre-corrects the shape of the projected image to suppress distortion of the display image caused by the positional relationship between the projector and the display surface 70 and the projection angle.

[0155] Furthermore, after geometric correction has been performed, it is preferable to correct the brightness of the region corresponding to the overlapping region 71 in the first projected image after the speed-up readout unit 236 reads the first projected image from the storage device 24.

[0156] In the embodiments illustrated above, the first projector 20 or 20A is configured to include the sensor 21, but the present invention is not limited thereto. For example, the first projector 20 or 20A may not include the sensor 21, and an inertial sensor, separate from the first projector 20 or 20A, may be fixed to a housing (not shown) of the first projector 20 or 20A. In this case, the first projector 20 or 20A may also obtain the output value of the inertial sensor via the communication device 25.

[0157] Furthermore, in the above embodiments, the projection device 22 of the first projector 20 or 20A is shown to have a liquid crystal panel structure, but the present invention is not limited thereto. For example, the projection device 22 may also have a structure that incorporates a digital micromirror device (DMD) instead of a liquid crystal panel. In this case, the DMD is an example of a display panel.

Claims

1. A display method, comprising the following processing: With the projector's position as a reference position, the brightness of the image corresponding to the overlapping area of ​​the first image displayed by the projector on the display surface and the second image displayed by other projectors on the display surface is attenuated based on a first attenuation coefficient determined according to the position within the overlapping area. If the position of the projector is displaced from the reference position, the first attenuation coefficient is corrected based on displacement information related to the displacement of the projector, calculated based on the output signal of the inertial sensor fixed to the projector. as well as If the position of the projector is displaced from the reference position, the brightness of the image in the first image corresponding to the overlapping area is reduced based on the corrected first attenuation coefficient.

2. The display method according to claim 1, wherein, The displacement information includes a displacement amount, which represents the magnitude of the projector's displacement, and a displacement direction, which represents the direction of the projector's displacement. The image display method further includes the following processing: when the position of the projector is displaced from the reference position, the first image is moved in the opposite direction to the displacement direction according to the amount of displacement.

3. The display method according to claim 1 or 2, wherein, The image display method further includes the following processing: sending position information, calculated based on the displacement information and related to the position of the overlapping area on the display surface, to the other projector.

4. The display method according to claim 1 or 2, wherein, The first attenuation coefficient is the ratio of the brightness of the image in the first image corresponding to the overlapping region to the brightness of the image in the first image corresponding to the region outside the overlapping region. The second attenuation coefficient is the ratio of the brightness of the image in the second image corresponding to the overlapping region to the brightness of the image in the second image corresponding to the region outside the overlapping region. The sum of the first attenuation coefficient and the second attenuation coefficient is 1.

5. A projector comprising a processing unit programmed to perform the following processing: With the projector's position as a reference position, the brightness of the image corresponding to the overlapping area of ​​the first image displayed by the projector on the display surface and the second image displayed by other projectors on the display surface is attenuated based on a first attenuation coefficient determined according to the position within the overlapping area. If the position of the projector is displaced from the reference position, the first attenuation coefficient is corrected based on displacement information related to the displacement of the projector, calculated based on the output signal of the inertial sensor fixed to the projector. as well as If the position of the projector is displaced from the reference position, the brightness of the image in the first image corresponding to the overlapping area is reduced based on the corrected first attenuation coefficient.

6. A projection system comprising: A first projector that displays a first image on a display surface; and A second projector displays a second image on the display surface. The first projector includes a processing unit programmed to perform the following processing: With the position of the first projector as the reference position, the brightness of the image in the first image corresponding to the overlapping area that overlaps the first image and the second image on the display surface is attenuated based on a first attenuation coefficient determined according to the position in the overlapping area; When the position of the first projector is displaced from the reference position, the first attenuation coefficient is corrected based on displacement information related to the displacement of the first projector, calculated based on the output signal of the inertial sensor fixed to the first projector. as well as If the position of the first projector is displaced from the reference position, the brightness of the image corresponding to the overlapping area in the first image is reduced based on the corrected first attenuation coefficient.

7. A projection system comprising: A first projector that displays a first image on a display surface; and A second projector displays a second image on the display surface. The first projector has: The first attenuation unit, with the position of the first projector as a reference position, attenuates the brightness of the image in the first image corresponding to the overlapping area that overlaps the first image and the second image on the display surface based on a first attenuation coefficient determined according to the position in the overlapping area; The computing unit calculates position information related to the position of the overlapping area on the display surface when the position of the first projector is displaced from the reference position, based on displacement information related to the displacement of the first projector calculated based on the output signal of the inertial sensor fixed to the first projector. An information output unit that outputs the location information to the second projector; as well as The correction unit corrects the first attenuation coefficient based on the displacement information. If the position of the first projector shifts from the reference position, the first attenuation unit, based on the corrected first attenuation coefficient, reduces the brightness of the image in the first image corresponding to the overlapping area. The second projector has: The second attenuation section attenuates the brightness of the image in the second image corresponding to the overlapping region based on a second attenuation coefficient determined according to the position within the overlapping region; The information acquisition unit acquires the location information; as well as The correction unit corrects the second attenuation coefficient based on the position information. The second attenuation part reduces the brightness of the second image based on the corrected second attenuation coefficient.

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