Projection display device and method for correcting display position of projected image

Abstract

An image shift correction amount storage unit (32) stores an image shift correction amount in correspondence with the elapsed time since the start of operation timed by a timekeeping unit (34) when a user uses a position adjustment unit (350) to adjust the display position of a projected image. When the device has started operating, the control unit (30) acquires a temperature index based on a temperature detected by a temperature sensor (20) and references a table retained in a table retention unit (31) to obtain an estimated elapsed time corresponding to the acquired temperature index. The control unit (30) controls the position adjustment unit (350) to adjust the display position of the projected image by the image shift correction amount corresponding to a corrected elapsed time, which is the result of adding the estimated elapsed time that was obtained to the actual elapsed time since the start of operation.

Description

Projection display device and method for correcting display position of projected image

[0001] The present disclosure relates to a projection display device and a method for correcting the display position of a projected image.

[0002] A projection display device projects an image onto a screen. After the power supply for the projection display device is turned on and the projection display device starts operating, the temperature inside the projection display device rises over time. This heat causes the optical components that make up the projection display device to expand, which can cause the display position of the image projected onto the screen to shift.

[0003] JP 2011-76029 A

[0004] A display method called a multi-screen is sometimes used in which the edges of images projected by two or more projection display devices are aligned on a screen to display an image larger than the image projected by a single projection display device. The amount of image shift, which is the shift in the display position of an image projected onto a screen by a projection display device, varies depending on the projection display device and can also vary depending on the installation conditions of the projection display device. The direction in which the display position of the projected image shifts also varies depending on the device and the installation conditions.

[0005] Therefore, when a multi-screen image in which the edges of two or more images are aligned is displayed using two or more projection display devices, the display positions of the images may shift over time, resulting in misalignment of the edges of the two or more images. If the edges of two or more images are misaligned, creating an unnatural-looking multi-screen image, the user must manually adjust the display positions of the images and realign the edges of the two or more images. This manual adjustment of the display positions of images is cumbersome, and improvements are needed.

[0006] One or more embodiments aim to provide a projection display device and a method for correcting the display position of a projected image that can automatically correct the display position of a projected image after the power is turned on and operation begins.

[0007] A first aspect of one or more embodiments includes an image projection unit that projects image light obtained by modulating illumination light according to image data onto a screen as a projection image; a position adjustment unit that adjusts a display position of the projection image displayed on the screen; a timer unit that measures the time since the device is powered on and starts operating; a temperature sensor that is attached to any part of the device and detects the temperature inside or outside the device; a table holder that holds a table that corresponds a temperature index based on the temperature detected by the temperature sensor when the device starts operating to an estimated elapsed time until the temperature index is reached assuming that the device starts operating at a preset room temperature; and a user adjusting the display position of the projection image displayed on the screen using the position adjustment unit. and a control unit that, when the device is powered on and starts operating, acquires a temperature index based on the temperature detected by the temperature sensor, refers to the table to acquire an estimated elapsed time corresponding to the acquired temperature index, reads out the elapsed time and the image deviation correction amount stored in the image deviation correction amount storage unit, and controls the position adjustment unit to adjust the display position of the projection image displayed on the screen by the image deviation correction amount corresponding to the corrected elapsed time obtained by adding the acquired estimated elapsed time to the actual elapsed time since the operation start time measured by the timing unit.

[0008] In a second aspect of one or more embodiments, when a power source of an apparatus is turned on and the apparatus starts operating, a timer measures the time since the apparatus started operating, and when a user adjusts the display position of a projection image displayed on a screen using a position adjustment unit that adjusts the display position of the projection image, the time elapsed since the operation start time measured by the timer and an image misalignment correction amount, which is an adjustment amount by which the display position of the projection image was adjusted, are stored in an image misalignment correction amount storage unit, and when the apparatus starts operating, an internal or external temperature of the apparatus detected by a temperature sensor attached to any part of the apparatus is obtained, and a table is stored. and a display position correction method for a projection image, the method comprising: obtaining an estimated elapsed time corresponding to the obtained temperature index by referring to a table, which is held in a holding unit and which corresponds to a temperature index based on the temperature detected by the temperature sensor when the device starts operating, and an estimated elapsed time until the temperature index is reached assuming that the device starts operating at a preset room temperature; reading out the elapsed time and the image deviation correction amount stored in the image deviation correction amount storage unit; and correcting the display position of the projection image displayed on the screen by an image deviation correction amount corresponding to the corrected elapsed time obtained by adding the obtained estimated elapsed time to the actual elapsed time measured by the timing unit since the start of the operation.

[0009] According to one or more embodiments of the projection display device and the method for correcting the display position of a projected image, the display position of a projected image can be automatically corrected after power is turned on and operation begins.

[0010] FIG. 1 is a conceptual block diagram of a projection display device according to one or more embodiments. FIG. 2 is a diagram illustrating a multi-screen image produced using two projection display devices. FIG. 3 is a diagram illustrating a multi-screen image in which the edges of two images are misaligned. FIG. 4 is a characteristics diagram illustrating an example of the relationship between the time elapsed since the projection display device started operating and the amount of image misalignment. FIG. 5 is a diagram illustrating a multi-screen image in which the display positions of the two images in FIG. 3 in which the edges are misaligned have been corrected. FIG. 6 is a diagram illustrating an example of the relationship between the time elapsed since the projection display device started operating and the amount of image misalignment stored in the image misalignment correction amount storage unit 32 of FIG. 1 . FIG. 7 is a diagram illustrating an example of the relationship between the time elapsed since the projection display device started operating and the amount of image misalignment correction, where the image misalignment correction amount is interpolated for elapsed times in which no image misalignment correction amount exists. FIG. 8 is a diagram illustrating an example of a table stored in the table storage unit 31 of FIG. 1 showing the correspondence relationship between the temperature at the start of operation and the estimated elapsed time. FIG. 9 is a flowchart illustrating the operation of a projection display device according to one or more embodiments and the processing performed by a method for correcting the display position of a projected image according to one or more embodiments.

[0011] A projection display device and a method for correcting the display position of a projected image according to one or more embodiments will be described below with reference to the accompanying drawings. In Fig. 1, a projection display device 100 according to one or more embodiments includes a light source 1, a light modulation element 2, a projection lens 3, a temperature sensor 20, a control unit 30, a table holder 31, an image misalignment correction amount storage unit 32, an operation unit 33, a timer 34, and an image data supply unit 35. Image data supplied from an external image data supply source is input to the image data supply unit 35 via an input terminal 36. The image data supply unit 35 includes a position adjustment unit 350.

[0012] The control unit 30 may be configured with a microprocessor. The table holding unit 31 may be configured with a memory such as a ROM. The image shift correction amount storage unit 32 may be configured with a memory such as a non-volatile memory. The table holding unit 31 and the image shift correction amount storage unit 32 may be configured with a single memory.

[0013] The light modulation element 2 generates image light by modulating the illumination light emitted from the light source 1 in accordance with image data supplied from the image data supply unit 35. The projection lens 3 projects an image formed by the image light modulated by the light modulation element 2 onto a screen 40. The light source 1, the light modulation element 2, and the projection lens 3 constitute an image projection unit that projects the image light, obtained by modulating the illumination light in accordance with the image data, onto the screen as a projection image.

[0014] The configuration of the image projection unit in the projection display device 100 is conceptually simplified. In reality, as understood from Patent Document 1, the projection display device 100 includes, as the light modulation elements 2, a red light modulation element that modulates red illumination light, a green light modulation element that modulates green illumination light, and a blue light modulation element that modulates blue illumination light. When the light source 1 emits white light, the projection display device 100 includes a separation optical system that separates the white light into red illumination light, green illumination light, and blue illumination light. The projection display device 100 also includes a synthesis optical system that synthesizes the red image light, green image light, and blue image light.

[0015] The light source 1 is not limited to a light source that emits white light, but may be a light source that combines a laser diode that emits blue laser light and a phosphor that is irradiated with the blue laser light and emits yellow illumination light. The light modulation element 2 may be a reflective liquid crystal display element called LCOS (Liquid Crystal On Silicon).

[0016] When the user operates the operation unit 33 to turn on the power of the projection display device 100 and the projection display device 100 starts operating, the timer unit 34 starts timing under the control of the control unit 30, and measures the time from the start of operation of the projection display device 100. The timer unit 34 can be configured with a counter.

[0017] As shown in Figure 2, an example will be taken where two projection display devices 100 are used to display a multi-screen image on a screen 40. The two projection display devices 100 are referred to as projection display devices 100A and 100B. The projection display device 100A projects light to the left of the screen 40 in a projection range 50A. The projection display device 100B projects light to the right of the screen 40 in a projection range 50B. The projection range 50A and the projection range 50B overlap at an overlapping range 50AB.

[0018] The projection display device 100A projects an image 51A having a predetermined pattern smaller than the projection range 50A onto the screen 40 within the projection range 50A. The projection display device 100B projects an image 51B having a predetermined pattern smaller than the projection range 50B onto the screen 40 within the projection range 50B. The area where the image 51A is located within the projection range 50A and the area where the image 51B is located within the projection range 50B are areas onto which the actual image light is projected. The images 51A and 51B are projected images based on image data. The areas outside the image 51A within the projection range 50A and the areas outside the image 51B within the projection range 50B are black images.

[0019] The right edge 51AR of the image 51A and the left edge 51BL of the image 51B are aligned so as to contact each other, forming a multi-screen image made up of the images 51A and 51B.

[0020] For example, assume that immediately after the projection display devices 100A and 100B start operating, the images 51A and 51B are aligned as shown in Fig. 2. Over time, the internal temperatures of the projection display devices 100A and 100B increase. Fig. 3 shows a state in which the projection ranges 50A and 50B have shifted from their initial positions shown in Fig. 2, resulting in a misalignment between the right edge 51AR of the image 51A and the left edge 51BL of the image 51B. Fig. 3 shows, as an example, a case in which the projection range 50A has shifted downward and to the right, and the projection range 50B has shifted upward and to the left.

[0021] As shown in Figure 4, after the projection display devices 100A and 100B are powered on and start operating, as the internal temperature rises over time, the display positions of the projection ranges 50A and 50B shift, and the amount of image misalignment increases. If the internal temperature is, for example, 20°C when the projection display devices 100A and 100B are powered on, the amount of image misalignment will remain constant with almost no increase after 120 minutes have passed. The room temperature may be set to a preset temperature, such as 20°C.

[0022] 1, the user recognizes the misalignment between the display positions of images 51A and 51B and operates operation unit 33 to adjust the display positions of both or either of images 51A and 51B. In response to the operation by operation unit 33, control unit 30 controls position adjustment unit 350 to adjust at least one of the position of image 51A within projection range 50A and the position of image 51B within projection range 50B. As a result, as shown in FIG. 5, the right edge 51AR of image 51A and the left edge 51BL of image 51B are aligned so that they come into contact with each other.

[0023] Each time the user recognizes a misalignment between the display positions of images 51A and 51B, the user may adjust at least one of the position of image 51A within projection range 50A and the position of image 51B within projection range 50B. That is, the user manually adjusts the display position of the projected image one or more times.

[0024] Image shift correction amount storage unit 32 stores the image shift correction amount, which is the amount by which the position of image 51A or 51B is adjusted by position adjustment unit 350. As shown in Fig. 4, it is assumed that the user corrects the image shift amount at elapsed times of 20 minutes, 50 minutes, 80 minutes, and 120 minutes. The image shift correction amounts at each time are Δc20, Δc50, Δc80, and Δc120. As shown in Fig. 6, image shift correction amount storage unit 32 stores the elapsed time at which the image shift amount was corrected and the image shift correction amount in association with each other.

[0025] Strictly speaking, the image shift correction amount stored in the image shift correction amount storage unit 32 consists of a horizontal image shift correction amount and a vertical image shift correction amount. For example, if the position of image 51A or 51B is corrected to the right in the horizontal direction, the value is positive. If the position of image 51A or 51B is corrected to the left in the horizontal direction, the value is negative. If the position of image 51A or 51B is corrected to the lower side in the vertical direction, the value is positive. If the position of image 51A or 51B is corrected to the upper side in the vertical direction, the value is negative. Therefore, the image shift correction amount stored in the image shift correction amount storage unit 32 consists of a positive or negative horizontal image shift correction amount corresponding to each elapsed time and a positive or negative vertical image shift correction amount.

[0026] When the position adjustment unit 350 corrects the image misalignment amount by the image misalignment correction amount Δc50 after 50 minutes have elapsed, the control unit 30 stores the total image misalignment correction amount (Δc20+Δc50) after 50 minutes have elapsed in the image misalignment correction amount storage unit 32. When the position adjustment unit 350 corrects the image misalignment amount by the image misalignment correction amount Δc80 after 80 minutes have elapsed, the control unit 30 stores the total image misalignment correction amount (Δc20+Δc50+Δc80) after 80 minutes have elapsed in the image misalignment correction amount storage unit 32.

[0027] When the position adjustment unit 350 corrects the image shift amount by the image shift correction amount Δc120 after 120 minutes have elapsed, the control unit 30 stores the image shift correction amount, which is the total image shift correction amount after 120 minutes has elapsed, that is, (Δc20 + Δc50 + Δc80 + Δc120), in the image shift correction amount memory unit 32.

[0028] As shown in Figure 7, the control unit 30 may interpolate the image shift correction amount for 10 minutes, 30 minutes, 40 minutes, etc., when the image shift amount has not actually been corrected. It is possible to predict in advance the characteristics with which the image shift amount will increase over time after the projection display device 100 starts operating. Therefore, the control unit 30 can generate an interpolated image shift correction amount for the elapsed time when the image shift amount has not been corrected. In Figure 7, the image shift correction amount with an i at the end is the interpolated image shift correction amount.

[0029] The image shift correction amount for each elapsed time shown in Figure 6 or 7 is updated if the user corrects the image shift amount at one or more elapsed times during the next operation of the projection display device 100. The final total image shift correction amount for each operation is stored in the image shift correction amount storage unit 32 until the next operation. In the example of Figure 6, the final image shift correction amount of (Δc20 + Δc50 + Δc80 + Δc120) is stored in the image shift correction amount storage unit 32 until the next operation.

[0030] 6 or 7 is stored in the image shift correction amount storage unit 32, the control unit 30 can automatically correct the display position of the image using the image shift correction amount stored in the image shift correction amount storage unit 32. However, the temperature inside the projection display device 100 is not necessarily room temperature when the projection display device 100 is turned on and starts operating. The projection display device 100 may be operated for a predetermined time, then turned off, and then turned on again shortly thereafter. In such a case, the internal temperature is higher than room temperature.

[0031] Therefore, the projection display device 100 is configured as follows so that the display position of the projected image can be appropriately corrected whether the internal temperature when the projection display device 100 starts operating is room temperature or a temperature higher than room temperature.

[0032] 1, the temperature sensor 20 is attached to the light modulation element 2. The temperature sensor 20 may detect the temperature of any of the optical elements inside the projection display device 100. The temperature sensor 20 may be attached to all of the red light modulation element, the green light modulation element, and the blue light modulation element, or may be attached to only one of the light modulation elements. The control unit 30 acquires the temperature detected by the temperature sensor 20 when the user operates the operation unit 33 to turn on the power of the projection display device 100 and the projection display device 100 starts operating.

[0033] If temperature sensors 20 are attached to all of the red light modulation elements, green light modulation elements, and blue light modulation elements, the control unit 30 may acquire the temperatures of the three temperature sensors 20 at the time the projection display device 100 starts operating and calculate an average temperature by averaging the three temperatures.

[0034] The table storage unit 31 stores a temperature-elapsed time conversion table, as shown in FIG. 8 , which associates multiple start-of-operation temperatures when the projection display device 100 starts operating with estimated elapsed times for each start-of-operation temperature. The start-of-operation temperatures are a first example of a temperature index based on temperatures detected by the temperature sensor 20. The estimated elapsed time indicates how much elapsed time the image shift amount at the start of operation for each start-of-operation temperature corresponds to, assuming that the projection display device 100 starts operating from a room temperature of, for example, 20°C. As shown in FIG. 8 , for example, the estimated elapsed time is 15 minutes when the start-of-operation temperature is 30°C, and 70 minutes when the start-of-operation temperature is 40°C. The temperature index may be the average temperature of the start-of-operation temperatures detected by the multiple temperature sensors 20.

[0035] 4, the amount of image misalignment differs depending on the time elapsed since the start of operation of the projection display device 100. If the temperature at the start of operation is 30°C, this essentially corresponds to 15 minutes elapsed since the projection display device 100 started operating at room temperature, so an image misalignment correction amount capable of correcting the amount of image misalignment at 15 minutes elapsed is required. If the temperature at the start of operation is 40°C, this essentially corresponds to 70 minutes elapsed since the projection display device 100 started operating at room temperature, so an image misalignment correction amount capable of correcting the amount of image misalignment at 70 minutes elapsed is required.

[0036] When the control unit 30 acquires the temperature at the time when the projection display device 100 starts operating, it references the temperature / elapsed time conversion table to acquire an estimated elapsed time. For example, when the control unit 30 acquires 30°C as the temperature at the time when the operation starts, it acquires an estimated elapsed time of 15 minutes.

[0037] Take the example of a case where the control unit 30 corrects the display position of an image using the image shift correction amount shown in Fig. 6. As shown in Fig. 6, the display position of the image can be corrected by the image shift correction amount Δc20 20 minutes after the projection display device 100 starts operating at room temperature. Because the control unit 30 has acquired an estimated elapsed time of 15 minutes, the point at which the corrected elapsed time, obtained by adding the estimated elapsed time of 15 minutes to the actual elapsed time measured by the timer unit 34, reaches 20 minutes, is the point at which the display position of the image should be corrected by the image shift correction amount Δc20.

[0038] The control unit 30 determines whether the corrected elapsed time, which is the actual elapsed time measured by the timing unit 34 plus the acquired estimated elapsed time, has reached any of the elapsed times shown in Fig. 6. If any of the elapsed times has been reached, the control unit 30 controls the position adjustment unit 350 to correct the display position of the projected image by the corresponding image misalignment correction amount.

[0039] Specifically, when the corrected elapsed time obtained by adding the estimated elapsed time of 15 minutes to the actual elapsed time reaches 20 minutes, control unit 30 controls position adjustment unit 350 to correct the display position of the projected image by image shift correction amount Δc20. When the corrected elapsed time obtained by adding the estimated elapsed time of 15 minutes to the actual elapsed time reaches 50 minutes, control unit 30 controls position adjustment unit 350 to further correct the display position of the image by image shift correction amount Δc50.

[0040] When the corrected elapsed time obtained by adding the estimated elapsed time of 15 minutes to the actual elapsed time reaches 80 minutes, control unit 30 controls position adjustment unit 350 to further correct the display position of the image by image shift correction amount Δc80. When the corrected elapsed time obtained by adding the estimated elapsed time of 15 minutes to the actual elapsed time reaches 120 minutes, control unit 30 controls position adjustment unit 350 to further correct the display position of the image by image shift correction amount Δc120.

[0041] Incidentally, the projection display device 100 may be configured to correct the display position of the projected image using the final total image shift correction amount stored in the image shift correction amount storage unit 32 from the previous operation. In such a case, the control unit 30 may calculate the image shift correction amount at each correction elapsed time as follows. Take the case where the image shift correction amount stored in the image shift correction amount storage unit 32 is (Δc20 + Δc50 + Δc80 + Δc120).

[0042] When the corrected elapsed time obtained by adding the estimated elapsed time of 15 minutes to the actual elapsed time reaches 20 minutes, control unit 30 controls position adjustment unit 350 to subtract the image misalignment correction amount (Δc50 + Δc80 + Δc120) from the image misalignment correction amount (Δc20 + Δc50 + Δc80 + Δc120) and correct the display position of the image by the image misalignment correction amount Δc20. When the corrected elapsed time obtained by adding the estimated elapsed time of 15 minutes to the actual elapsed time reaches 50 minutes, control unit 30 controls position adjustment unit 350 to subtract the image misalignment correction amount (Δc80 + Δc120) from the image misalignment correction amount (Δc20 + Δc50 + Δc80 + Δc120) and correct the display position of the image by the image misalignment correction amount (Δc20 + Δc50).

[0043] When the corrected elapsed time obtained by adding the estimated elapsed time of 15 minutes to the actual elapsed time reaches 80 minutes, control unit 30 controls position adjustment unit 350 to subtract the image misalignment correction amount Δc120 from the image misalignment correction amount (Δc20+Δc50+Δc80+Δc120) and correct the display position of the image by the image misalignment correction amount (Δc20+Δc50+Δc80).When the corrected elapsed time obtained by adding the estimated elapsed time of 15 minutes to the actual elapsed time reaches 120 minutes, control unit 30 controls position adjustment unit 350 to correct the display position of the image by the image misalignment correction amount (Δc20+Δc50+Δc80+Δc120).

[0044] When the control unit 30 acquires a temperature of 35°C as the start of operation, it acquires an estimated elapsed time of 40 minutes. In this case, the control unit 30 determines that the corrected elapsed time obtained by adding the estimated elapsed time of 40 minutes to the actual elapsed time when the actual elapsed time is 0 has reached 20 minutes, which is the elapsed time shown in Figure 6. Therefore, in this case, the control unit 30 immediately controls the position adjustment unit 350 to correct the display position of the image by the image misalignment correction amount Δc20.

[0045] In this way, the position adjustment unit 350 can appropriately correct the display position of the projected image in accordance with the control of the control unit 30, regardless of the internal temperature when the projection display device 100 starts operating.

[0046] The projection display device 100 may be configured as follows. In FIG. 1 , in addition to the temperature sensor 20 (first temperature sensor) attached to the light modulation element 2, a temperature sensor (second temperature sensor) may be attached to an optical element other than the light modulation element 2 or to another location. In this case, the projection display device 100 includes two or more temperature sensors including the first temperature sensor. The second temperature sensor may be attached to the light source 1. The second temperature sensor may be attached to any location of the projection display device 100 so as to detect the temperature outside the projection display device 100.

[0047] The control unit 30 acquires the temperatures detected by the first temperature sensor and the second temperature sensor and calculates the temperature difference between them. Instead of the temperature-elapsed time conversion table shown in Fig. 8, the table storage unit 31 stores a temperature difference-elapsed time conversion table that associates multiple operation start temperature differences between temperatures detected by two or more temperature sensors with the estimated elapsed time until each operation start temperature difference is reached. The operation start temperature difference is a second example of a temperature index based on the temperatures detected by the first and second temperature sensors.

[0048] The control unit 30 acquires the temperature difference at the start of operation when the projection display device 100 starts operating. The control unit 30 references the temperature difference / elapsed time conversion table to acquire an estimated elapsed time corresponding to the temperature difference at the start of operation. The control unit 30 determines whether the corrected elapsed time, which is the sum of the acquired estimated elapsed time and the actual elapsed time since the start of operation measured by the timing unit 34, has reached any one of the one or more elapsed times read from the image shift correction amount storage unit 32.

[0049] If the correction elapsed time reaches any one of the elapsed times, the control unit 30 controls the position adjustment unit 350 to adjust the display position of the projected image by the image shift correction amount corresponding to the elapsed time that has been reached.

[0050] 9, the operation of the projection display device 100 and the method for correcting the display position of a projected image executed by the projection display device 100 will be described. Fig. 9 shows the operation when the temperature / elapsed time conversion table shown in Fig. 8 is stored in the table storage unit 31.

[0051] 9 , when the projection display device 100 is powered on and processing begins, the timer 34 begins timing in step S1 under control of the control unit 30. The control unit 30 acquires the start-of-operation temperature in step S2. The control unit 30 acquires the estimated elapsed time corresponding to the start-of-operation temperature in step S3. The control unit 30 reads out the elapsed time and the image misalignment correction amount stored in the image misalignment correction amount storage unit 32 in step S4.

[0052] In step S5, the control unit 30 determines whether the corrected elapsed time, which is the sum of the actual elapsed time and the estimated elapsed time, has reached any of the read-out elapsed times. If the corrected elapsed time has not reached any of the elapsed times (NO), the control unit 30 repeats the process of step S5. If the corrected elapsed time has reached any of the elapsed times (YES), the control unit 30 controls the position adjustment unit 350 to correct the display position of the projected image by the read-out image misalignment correction amount in step S6.

[0053] Next, in step S7, the control unit 30 determines whether the display positions of the projected images have been corrected by the image shift correction amounts corresponding to all of the elapsed times. If the display positions of the projected images have not been corrected by the image shift correction amounts corresponding to all of the elapsed times (NO), the control unit 30 repeats the processes of steps S5 to S7. If the display positions of the projected images have been corrected by the image shift correction amounts corresponding to all of the elapsed times (YES), the control unit 30 ends the process.

[0054] The present invention is not limited to one or more of the above-described embodiments, and various modifications are possible within the scope of the present invention. The position adjustment unit 350 adjusts the display position of the projected image (image 51A or 51B) by adjusting the position of the projected image within the projection range 50A or 50B. However, the position of the projection range 50A or 50B on the screen 40 may also be optically adjusted. For example, the projection lens 3 may be configured to be movable, and the position of the projection range 50A or 50B on the screen 40 may be adjusted by moving the projection lens 3. In this case, the images 51A and 51B do not need to be smaller than the projection ranges 50A and 50B, respectively. The images 51A and 51B may be the same as the projection ranges 50A and 50B, respectively. The entire projection ranges 50A and 50B can be a projected image having a predetermined pattern.

[0055] This application claims priority based on Japanese Patent Application No. 2022-066040, filed with the Japan Patent Office on April 13, 2022, the entire disclosure of which is incorporated herein by reference.

Claims

1. an image projection unit that projects image light obtained by modulating illumination light in accordance with image data onto a screen as a projection image; a position adjustment unit that adjusts a display position of the projection image displayed on the screen; a timer unit that measures time from a start point when the device is powered on and starts operating; an image shift correction amount storage unit that stores, in association with each other, an image shift correction amount obtained by adjusting the image shift amount of the projection image displayed on the screen by the position adjustment unit and an elapsed time from the start of the operation measured by the timer unit when a user adjusts an image shift amount by which the display position of the projection image displayed on the screen is shifted; a control unit that controls said position adjustment unit to store the elapsed time and the image shift correction amount in said image shift correction amount storage unit, to interpolate a pixel shift correction amount at an elapsed time during which the image shift amount of the projection image is not adjusted from the elapsed time and the image shift correction amount stored in said image shift correction amount storage unit, and to update the image shift correction amount stored in said image shift correction amount storage unit and adjust a display position of the projection image displayed on the screen by the image shift correction amount corresponding to the elapsed time if the image shift amount is corrected at one or more elapsed times; A projection display device comprising:

2. A temperature sensor attached to any part of the device to detect an internal or external temperature of the device; a table storage unit that stores a table that associates a temperature index based on a temperature detected by the temperature sensor when the device starts to operate with an estimated elapsed time until the temperature index is reached when it is assumed that the device starts to operate at a preset room temperature; Further equipped with The control unit is When the device is powered on and starts operating, a temperature index based on the temperature detected by the temperature sensor is obtained, an estimated elapsed time corresponding to the obtained temperature index is obtained by referring to the table, the elapsed time and the image shift correction amount stored in the image shift correction amount storage unit are read out, and the display position of the projected image displayed on the screen is adjusted by the image shift correction amount corresponding to the corrected elapsed time obtained by adding the obtained estimated elapsed time to the actual elapsed time measured by the timer unit since the start of the operation.

2. The projection display device according to claim 1.

3. The temperature sensor includes a first temperature sensor that detects a temperature of any optical element inside the device; The table associates an operation start temperature detected by the first temperature sensor as the temperature index with an estimated elapsed time until the temperature reaches the operation start temperature when it is assumed that the device starts operation at a preset room temperature.

3. The projection display device according to claim 2.

4. The temperature sensor includes a plurality of temperature sensors, The table associates an average temperature at the start of operation detected by the plurality of temperature sensors as the temperature index with an estimated elapsed time until the temperature reaches the average temperature when it is assumed that the device starts operation at a preset room temperature.

3. The projection display device according to claim 2.

5. The temperature sensor includes a first temperature sensor for detecting a temperature of any one of the optical elements inside the device, and a second temperature sensor for detecting a temperature of another optical element or another portion, The table associates, as the temperature index, an operation start temperature difference, which is a difference between an operation start temperature detected by the first temperature sensor and an operation start temperature detected by the second temperature sensor, with an estimated elapsed time until the operation start temperature difference is reached when it is assumed that the device starts operation at a preset room temperature.

3. The projection display device according to claim 2.

6. the projected image is smaller than a projection range of light projected by the image projection unit onto the screen, The position adjustment unit adjusts the display position of the projection image by adjusting the position of the projection image within the projection range.

6. The projection display device according to claim 1.

7. the image projection unit includes a movable projection lens; the projection image has the same projection range as the light projected by the image projection unit onto the screen, The position adjustment unit adjusts the display position of the projected image by moving the projection lens.

6. The projection display device according to claim 1.

8. 6. The projection display device according to claim 1, wherein the projected image, the display position of which is adjusted, is an image having a predetermined pattern.

9. 6. The projection display device according to claim 1, wherein the image shift correction amount stored in the image shift correction amount storage section comprises an image shift correction amount in a horizontal direction and an image shift correction amount in a vertical direction.

10. When the power supply of the device is turned on and the device starts operating, the timer measures the time from the start of the operation of the device, when a user adjusts an image shift amount by which a display position of a projection image displayed on a screen is shifted using a position adjustment unit that adjusts a display position of the projection image displayed on the screen, an image shift correction amount, which is an adjustment amount obtained by adjusting the image shift amount of the projection image, is stored in an image shift correction amount storage unit in correspondence with the elapsed time from the operation start point measured by the timing unit, a pixel shift correction amount for an elapsed time during which the display position of the projection image is not adjusted is interpolated from the elapsed time and the image shift correction amount stored in the image shift correction amount storage unit, and the pixel shift correction amount is stored in the image shift correction amount storage unit; If the image shift amount is corrected at one or more elapsed times, the image shift correction amount stored in the image shift correction amount storage unit is updated; The display position of the projected image displayed on the screen is adjusted by the position adjustment unit by the image deviation correction amount corresponding to the elapsed time stored in the image deviation correction amount storage unit. A method for correcting the display position of a projected image.