Circuitry device and head-up display device

Abstract

To provide a circuit arrangement that can notify a host of information on trouble in a backlight considering distortion correction.SOLUTION: A circuit arrangement 100 is used for a display unit. The display unit includes a display panel 340, and a backlight 330 that has a plurality of light sources. The circuit arrangement 100 includes a distortion correction circuit 110, a failure information acquisition circuit 150, a position information acquisition circuit 160, and an interface circuit for a host 191. The distortion correction circuit 110 performs distortion correction for input image data IMA and outputs output image data IMB after the distortion correction. The failure information acquisition circuit 150 acquires failure information LE on the light sources 332. The position information acquisition circuit 160 converts panel-side light source position information on a failed light source on the display panel 340 indicated by the failure information LE into input-side light source position information on the input image data IMA. The interface circuit for the host 191 outputs the input-side light source position information to the host.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a circuit device, a head-up display device, and the like.

Background Art

[0002] Patent Document 1 discloses a circuit device including an image processing circuit and a comparison circuit. The image processing circuit performs a first mapping process of mapping an input first image to a second image for projection onto a projection object, and a second mapping process of converting the second image into a third image by an inverse mapping process of the first mapping process. The comparison circuit compares the first image and the third image, and outputs the result of the comparison as information for performing error detection of the second image. Patent Document 1 also discloses notifying an external device of the circuit device, such as a SoC or a CPU, of the result of error detection.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] If there is a defect in the backlight of the display device, the visibility of the display image may decrease. For this reason, there is a problem that it is desired to notify the host of the defect in the backlight. In the above Patent Document 1, although an error in image data is notified to a SoC or a CPU, neither disclosure nor suggestion of notifying a defect in the backlight is made.

Means for Solving the Problems

[0005] One aspect of the present disclosure relates to a circuit device used in a display device that includes a display panel and a backlight having a plurality of light sources, wherein each of the plurality of light sources is provided corresponding to each of a plurality of areas of the display panel, and the circuit device includes: a distortion correction circuit that performs distortion correction on input image data and outputs distortion-corrected output image data; a fault information acquisition circuit that acquires fault information for each of the light sources; a position information acquisition circuit that converts the panel-side light source position information on the display panel of the fault light source indicated by the fault information into input-side light source position information on the input image data; and a host interface circuit that outputs the input-side light source position information to a host.

[0006] Another aspect of the present disclosure relates to a head-up display device comprising the circuit device described above, a display panel for displaying an image based on the output image data, a backlight, and a projection optical system for projecting the image displayed on the display panel. [Brief explanation of the drawing]

[0007] [Figure 1] An example configuration of a head-up display device. [Figure 2] Detailed configuration example of the display unit. [Figure 3] Detailed configuration example of a circuit device. [Figure 4] A diagram illustrating fault information and the position information of the light source on the panel side. [Figure 5] A diagram illustrating the position information of the light source on the panel side and the light source on the input side. [Figure 6] An example where the area illuminated by a light source is used as light source position information in a display panel. [Figure 7] An example where the margin area on the input image data is used as light source position information. [Figure 8] A diagram illustrating the process for detecting distortion correction errors. [Modes for carrying out the invention]

[0008] Preferred embodiments of this disclosure will be described in detail below. These embodiments are not intended to unduly limit the scope of the claims, and not all configurations described in these embodiments are necessarily essential.

[0009] 1.Display device Figure 1 shows an example configuration of a head-up display device 50, which includes the circuit device 100 of this embodiment. The head-up display device 50 includes the circuit device 100, a display unit 300, and a projection optical system 52.

[0010] The processing unit 200 transmits image data to the circuit unit 100 of the head-up display device 50. The processing unit 200 is a so-called SoC, which is a processor such as a CPU or microcomputer. SoC stands for System on Chip. CPU stands for Central Processing Unit.

[0011] The circuit device 100 performs distortion correction on the image data received from the processing device 200 and transmits the distortion-corrected image data to the display unit 300. Distortion correction is an image correction process that applies an image distortion to the image that is the opposite of the image distortion that occurs when the image displayed on the display panel is projected, in order to create a HUD display with no distortion or reduced distortion. HUD stands for Head-Up Display. Image distortion due to projection includes image distortion due to the curved surface of the screen 20, image distortion due to the projection optical system 52, or both. The circuit device 100 is, for example, an integrated circuit device in which multiple circuit elements are integrated on a semiconductor substrate.

[0012] The display unit 300 includes a display panel and a backlight, and displays distortion-corrected image data from the circuit device 100 on the display panel. The backlight emits light onto the display panel. The projection optical system 52 includes a reflector, etc. The reflector reflects the light that has passed through the display panel toward the screen 20, and the light reflected by the screen 20 enters the user's eyes 10. As a result, a virtual image corresponding to the image displayed on the display panel is projected into the user's field of view. The screen 20 transmits light from the real space that is the background of the HUD display. As a result, the virtual image from the HUD appears superimposed on the real space to the user's eyes 10. The screen 20 is, for example, the windscreen of a mobile device equipped with a head-up display device 50.

[0013] 2. Circuit device and display unit Figure 2 shows a detailed configuration example of the display unit 300. The display unit 300 includes a processing unit 310, a light source driver 320, a backlight 330, and a display panel 340.

[0014] The processing unit 310 performs conversion between the communication format used by the light source interface circuit 192 of the circuit device 100 and the communication format used by the light source driver 320. The processing unit 310 is, for example, a processor such as a CPU or microcomputer. Alternatively, the processing unit 310 may be omitted, and the light source interface circuit 192 and the light source driver 320 may communicate directly.

[0015] The backlight 330 includes a plurality of light sources two-dimensionally arranged in a plan view. Each light source is a light-emitting element such as an LED. LED is an abbreviation for Light Emitting Diode. The backlight 330 is arranged to overlap the display panel 340 so that the side on which the plurality of light sources are arranged faces the display panel 340 in a plan view. Thereby, the emitted light from the plurality of two-dimensionally arranged light sources is incident on the display panel 340. The two-dimensional arrangement of the light sources is, for example, a matrix arrangement, but is not limited thereto, and may be, for example, a staggered arrangement. The staggered arrangement is, for example, an arrangement in which light sources are arranged in odd-numbered columns in odd-numbered rows and in even-numbered columns in even-numbered rows.

[0016] The light source driver 320 drives each light source of the backlight 330 based on the light source control data from the light source interface circuit 192. The light source driver 320 also detects a failure of each light source of the backlight 330 and transmits the failure information to the light source interface circuit 192. The light source driver 320 includes the first driver DR1 to the nth driver DRn. n is an integer of 1 or more. Each driver is composed of, for example, an integrated circuit device.

[0017] Specifically, the first driver DR1 drives some of the plurality of light sources of the backlight 330. The first driver DR1 independently lights or turns off each light source in charge. In addition, the first driver DR1 causes each light source in charge to emit light with the light amount set by the circuit device 100. This light amount can be set independently for each light source. The same applies to the second driver DR2 to the nth driver DRn.

[0018] The first driver DR1 detects a failure of each light source it is in charge of. A failure of a light source means a state where the driver cannot control the lighting, extinguishing, or light output of the light source. A failure of a light source is, for example, an open or short circuit of a light-emitting element. An open circuit of a light-emitting element means a state where illumination is extinguished or the light output cannot be controlled at a low level due to a disconnection. The first driver DR1 detects an open circuit of a light-emitting element, for example, by comparing the anode voltage of the light-emitting element with a threshold voltage for open detection. A short circuit of a light-emitting element means a state where illumination is turned on or the light output cannot be controlled at a high level due to a short circuit such as a power supply. The first driver DR1 detects a short circuit, for example, by comparing the anode voltage of the light-emitting element with a threshold voltage for short detection.

[0019] The first driver DR1 to the nth driver DRn are connected in a cascade communication manner. That is, the first driver DR1 receives input data SDI such as light source control data from the processing device 310 and transmits the input data SDI to the second driver DR2. By repeating this up to the nth driver DRn, the input data SDI is transmitted to the first driver DR1 to the nth driver DRn. Also, the first driver DR1 transmits output data such as failure information of the light source to the second driver DR2. The second driver DR2 adds the transmission data of the second driver DR2 to the transmission data from the first driver DR1 and transmits it to the third driver DR3. This is repeated up to the nth driver DRn. The nth driver DRn transmits output data SDO including the output data of the first driver DR1 to the nth driver DRn to the processing device 310. Note that the communication connection method between the processing device 310 and the first driver DR1 to the nth driver DRn is not limited to the above, and connection methods in various communication methods may be adopted.

[0020] The display panel 340 is, for example, a liquid crystal display panel. The liquid crystal display panel may be either transmissive or reflective. The display unit 300 includes a display controller (not shown) and a display driver. The display driver outputs a timing control signal to the display driver for controlling the display timing, along with the output image data IMB from the output circuit 130. The display driver drives the display panel 340 based on the output image data IMB and the timing control signal, and displays the image from the output image data IMB on the display panel 340. The function of the display controller may be built into the circuit device 100.

[0021] Figure 3 shows a detailed configuration example of the circuit device 100. The circuit device 100 includes an input circuit 105, a strain correction circuit 110, an inverse strain correction circuit 120, an output circuit 130, a strain correction error detection circuit 140, a fault information acquisition circuit 150, a position information acquisition circuit 160, a storage circuit 165, an error processing circuit 170, a light source control circuit 180, a host interface circuit 191, and a light source interface circuit 192.

[0022] The input circuit 105 receives input image data (IMA) from the processing unit 200. The input circuit 105 may be a receiving circuit for various communication interfaces, but examples include LVDS, DVI, DisplayPort, GMSL, or GVIF. LVDS stands for Low Voltage Differential Signaling, DVI stands for Digital Visual Interface, GMSL stands for Gigabit Multimedia Serial Link, and GVIF stands for Gigabit Video Interface.

[0023] The distortion correction circuit 110 performs distortion correction on the input image data IMA using a coordinate transformation between the pixel coordinates in the input image data IMA and the pixel coordinates in the output image data IMB, and outputs the result as the output image data IMB. The distortion correction circuit 110 corresponds to either a reverse warp engine or a forward warp engine. Reverse warp is a warp process that transforms the pixel coordinates on the output image data IMB to their corresponding reference coordinates, and then obtains the pixel data of the output image data IMB from the pixel data of the input image data IMA at those reference coordinates. Forward warp is a warp process that transforms the pixel coordinates on the input image data IMA to their corresponding destination coordinates, and then obtains the pixel data of the output image data IMB at the destination coordinates from the pixel data of the input image data IMA at those pixel coordinates. The coordinate transformations in reverse warp and forward warp are defined by warp parameters. Warp parameters include a table that maps coordinates on the input image data IMA to coordinates on the output image data IMB, a table that shows the amount of movement between the coordinates on the input image data IMA and the coordinates on the output image data IMB, or coefficients of a polynomial that maps the coordinates on the input image data IMA and the coordinates on the output image data IMB.

[0024] The output circuit 130 transmits the output image data IMB to the display unit 300. The output circuit 130 may be a transmission circuit for various communication interfaces, but examples include transmission circuits for LVDS, DVI, DisplayPort, GMSL, or GVIF.

[0025] The light source interface circuit 192 communicates with the light source driver 320 via the processing unit 310 of the display unit 300. The light source interface circuit 192 may be any of the various communication interfaces used for communication between circuit devices, but examples include SPI or I2C. SPI stands for Serial Peripheral Interface. I2C stands for Inter Integrated Circuit. Note that the light source interface circuit 192 and the host interface circuit 191 are not limited to individually provided interface circuits, but may be a single common interface circuit.

[0026] The light source control circuit 180 transmits light source control data to the light source driver 320 via the light source interface circuit 192 and the processing unit 310. The light source control data controls the on / off status or light intensity of each light source of the backlight 330. The light source control circuit 180 may, for example, perform local dimming control to adjust the brightness of each light source based on the results of image analysis of the input image data IMA or output image data IMB.

[0027] The fault information acquisition circuit 150 acquires fault information LE for each light source of the backlight 330 from the light source driver 320 via the processing unit 310 and the light source interface circuit 192. The fault information includes information indicating the position of each light source in the backlight 330, and information indicating whether each light source is normal, open, or short-circuited. The information indicating the position of each light source in the backlight 330 is not limited to information indicating the position itself, but may also be information such as an index that can identify which light source it is.

[0028] The position information acquisition circuit 160 acquires input-side light source position information on the input image data IMA based on the fault information LE from the fault information acquisition circuit 150. The input-side light source position information indicates which position on the input image data IMA corresponds to the position of the faulty light source. Specifically, the position information acquisition circuit 160 refers to the conversion table 167 stored in the memory circuit 165 and converts the panel-side light source position information on the display panel 340 of the faulty light source indicated by the fault information into input-side light source position information on the input image data IMA. The position information is, for example, the coordinates on the image corresponding to the light source, but is not limited to this, and may also be information of a region containing those coordinates. The region may be indicated by the coordinates of the vertices of a rectangle, or by the coordinates of each pixel included in the region.

[0029] The conversion table 167 may be stored in the memory circuit 165 during the manufacturing of the head-up display device 50, or it may be written to the memory circuit 165 from the processing unit 200 via the host interface circuit 191. The memory circuit 165 is a non-volatile memory such as EEPROM or OTP memory, or a volatile memory such as SRAM. EEPROM stands for Electrically Erasable Programmable Read Only Memory. OTP stands for One Time Programmable. SRAM stands for Static Random Access Memory.

[0030] The inverse distortion correction circuit 120 generates inverse distortion-corrected image data IMC by performing inverse distortion correction, which is the inverse correction of the distortion correction performed by the distortion correction circuit 110, on the output image data IMB. The inverse distortion correction circuit 120 may be either a reverse map engine or a forward map engine. Furthermore, the inverse distortion correction circuit 120 may use either warp processing using a table or warp processing using a polynomial.

[0031] The distortion correction error detection circuit 140 detects distortion correction errors by comparing the input image data IMA with the inverse distortion-corrected image data IMC. Distortion correction errors are processing errors that occur during image processing performed by the distortion correction circuit 110 or the inverse distortion correction circuit 120. The distortion correction error detection circuit 140 detects regions where the input image data IMA and the inverse distortion-corrected image data IMC do not match and outputs information identifying these regions as distortion correction error location information YE. For example, the distortion correction error detection circuit 140 detects regions where the degree of match is below a predetermined level based on the SSD or SAD of the input image data IMA and the inverse distortion-corrected image data IMC. SSD stands for Sum of Squared Difference. SAD stands for Sum of Absolute Difference.

[0032] The host interface circuit 191 communicates with the processing unit 200, which is the host of the circuit device 100. The host interface circuit 191 may be any of the various communication interfaces used for communication between circuit devices, such as SPI or I2C. As mentioned above, the light source interface circuit 192 and the host interface circuit 191 may be a single common interface circuit.

[0033] The error processing circuit 170 performs error processing based on the input-side light source position information and distortion correction error position information YE obtained by the position information acquisition circuit 160 based on the light source failure information LE. Specifically, the input-side light source position information and distortion correction error position information YE are stored in the memory circuit 165 or a register (not shown). When a light source failure, distortion correction error, or both occur, the error processing circuit 170 sends an interrupt signal to the processing unit 200 via the host interface circuit 191. When the processing unit 200 receives the interrupt signal, it reads the input-side light source position information and distortion correction error position information YE from the memory circuit 165 or a register (not shown) via the host interface circuit 191.

[0034] The processing unit 200 handles errors based on the input light source position information and the distortion correction error position information YE. For example, it moves the display object in the area where the light source failure or distortion correction error has occurred to an area where neither the light source failure nor the distortion correction error has occurred, and outputs the input image data IMA after the move to the circuit device 100. Alternatively, the processing unit 200 may stop outputting the input image data IMA when a light source failure or distortion correction error occurs. Alternatively, the error processing circuit 170 of the circuit device 100 may stop outputting the output image data IMB from the output circuit 130 when a light source failure or distortion correction error occurs.

[0035] The distortion correction circuit 110, the inverse distortion correction circuit 120, the distortion correction error detection circuit 140, the fault information acquisition circuit 150, the position information acquisition circuit 160, the error processing circuit 170, and the light source control circuit 180 are logic circuits. Each of these circuits may be configured as an individual logic circuit, or as an integrated logic circuit by automatic placement and routing or the like. Furthermore, some or all of these circuits may be implemented by a processor such as a DSP. DSP stands for Digital Signal Processor. In this case, a program or instruction set describing the function of each circuit is stored in memory, and the function of each circuit is realized by the processor executing that program or instruction set.

[0036] 3. Detailed example of the process The following describes a detailed example of the processing performed by the circuit device 100. The following example uses the case where multiple backlight sources 332 are arranged in a matrix.

[0037] Figure 4 illustrates fault information and panel-side light source position information. As shown in the left figure, the column number of the light source matrix is ​​denoted as i, the row number as j, and the position of the light source on the backlight is indicated as (i,j). i and j are integers greater than or equal to 1. Figure 4 shows an example where the light source at (3,2) is a faulty light source. The fault information acquired by the fault information acquisition circuit 150 includes the position of the faulty light source (3,2) and a flag indicating whether the faulty light source is in an open or short state. Note that there may be two or more faulty light sources.

[0038] As shown in the right-hand diagram of Figure 4, in a plan view of the display panel, the backlight is positioned overlapping the back of the display panel. The light source 332 illuminates area 333 on the display panel. The size of area 333 may be fixed or may change according to the light intensity of the light source 332. Although only one area 333 is shown in the right-hand diagram of Figure 4, there are areas corresponding to each light source 332.

[0039] The pixel coordinates of the display panel are denoted by (x,y). x is the coordinate in the horizontal scanning direction, and y is the coordinate in the vertical scanning direction. The horizontal scanning direction is assumed to be parallel to the rows of the light source matrix. In this case, in a plan view, the light source position (i,j) on the backlight corresponds to the pixel coordinates (x,y) on the display panel. Based on this correspondence, the position information acquisition circuit 160 converts the position of the faulty light source (3,2) into panel-side light source position information. The panel-side light source position information includes, for example, the pixel coordinates corresponding to the center point of the light source, the pixel coordinates corresponding to the vertices of the rectangular area illuminated by the light source, or the coordinates of each pixel included in the area illuminated by the light source.

[0040] Figure 5 illustrates the panel-side light source position information and the input-side light source position information. As shown in the left figure, the pixel coordinates on the input image data IMA are denoted by (u,v). u is the coordinate in the horizontal scanning direction, and v is the coordinate in the vertical scanning direction. As shown in the right figure, the pixel coordinates on the output image data IMB are denoted by (x,y). The distortion correction circuit 110 performs a coordinate transformation between the coordinates (u,v) on the input image data IMA and the coordinates (x,y) on the output image data IMB, and maps the input image data IMA to the output image data IMB based on the result.

[0041] The position information acquisition circuit 160 converts the panel-side light source position information of the faulty light source into input-side light source position information based on the correspondence between the coordinates (u,v) on the input image data IMA and the coordinates (x,y) on the output image data IMB in distortion correction. For example, a conversion table 167 showing the correspondence between (x,y) and (u,v) based on the warp parameters of distortion correction is created in advance and stored in the memory circuit 165. The position information acquisition circuit 160 uses this conversion table 167 to map the coordinates (x,y) on the display panel of the faulty light source to the coordinates (u,v) on the input image data IMA.

[0042] Figure 5 shows an example where the center coordinates of the light source are used as the light source position information. That is, the coordinates of the intersection of a line passing through the center of the faulty light source and perpendicular to the display panel and the display panel are defined as the center coordinates (x,y) of the faulty light source on the display panel. The position information acquisition circuit 160 converts the center coordinates (x,y) of the faulty light source on the display panel into coordinates (u,v) on the input image data IMA. These coordinates (u,v) become the input light source position information.

[0043] In this embodiment, the circuit device 100 is used as a display device. The display device includes a display panel 340 and a backlight 330 having multiple light sources. Each of the multiple light sources 332 is provided corresponding to each of the multiple areas 333 of the display panel 340. The circuit device 100 includes a distortion correction circuit 110, a fault information acquisition circuit 150, a position information acquisition circuit 160, and a host interface circuit 191. The distortion correction circuit 110 performs distortion correction on the input image data IMA and outputs distortion-corrected output image data IMB. The fault information acquisition circuit 150 acquires fault information LE for each of the light sources 332. The position information acquisition circuit 160 converts the panel-side light source position information on the display panel 340 of the fault light source indicated by the fault information LE into input-side light source position information on the input image data IMA. The host interface circuit 191 outputs the input-side light source position information to the host.

[0044] According to this embodiment, a malfunction of the backlight 330 can be notified to the host. When distortion correction is performed, it is necessary to notify the host of the location information of the faulty light source on the input image data IMA, taking mapping into consideration. According to this embodiment, the panel-side light source location information on the display panel 340 of the faulty light source is converted into input-side light source location information on the input image data IMA. This allows the host to be notified of the location information of the faulty light source, taking mapping in distortion correction into consideration, and the host can perform processing to address the light source malfunction in the input image data IMA based on that location information.

[0045] In the examples in Figures 1 and 2, the host corresponds to the processing unit 200. In the example in Figure 5, the input light source position information is the center coordinates of the faulty light source. However, as will be described later in Figure 6 or 7, the input light source position information is not limited to the center coordinates of the faulty light source.

[0046] In this embodiment, the circuit device 100 also includes a light source interface circuit 192. The light source interface circuit 192 performs interface processing with a light source driver 320 that drives multiple light sources. The fault information acquisition circuit 150 acquires fault information LE via the light source interface circuit 192.

[0047] According to this embodiment, the fault information acquisition circuit 150 can acquire fault information LE for each light source detected by the light source driver 320 via the light source interface circuit 192. Then, the position information acquisition circuit 160 can acquire the input side light source position information of the faulty light source based on the fault information LE.

[0048] In this embodiment, the position information acquisition circuit 160 receives the position coordinates (x,y) of the faulty light source on the display panel 340 as panel-side light source position information. The position information acquisition circuit 160 performs inverse distortion correction on the position coordinates (x,y) to obtain input-side light source position information.

[0049] According to this embodiment, the position coordinates (x,y) of the faulty light source on the display panel 340 are converted to the position coordinates (u,v) of the input image data IMA by inverse distortion correction. As a result, the position coordinates (u,v) of the faulty light source on the input image data IMA are output to the host as input light source position information.

[0050] In the example in Figure 5, the position coordinates (x,y) of the faulty light source on the display panel 340 are the center coordinates of the faulty light source. However, the position coordinates do not necessarily have to be the center coordinates of the faulty light source; for example, they could be the position coordinates of the point that would have the highest brightness in the brightness distribution on the display panel illuminated by the faulty light source if it were not faulty. In the example in Figure 3, the inverse distortion correction for the position coordinates corresponds to a coordinate transformation using the transformation table 167. However, the inverse distortion correction for the position coordinates can be performed using any coordinate transformation method as long as the position coordinates (x,y) on the display panel 340 can be transformed into the position coordinates (u,v) of the input image data IMA.

[0051] In this embodiment, the circuit device 100 also includes a memory circuit 165. The memory circuit 165 stores a conversion table 167 that associates the position information of each light source 332 on the display panel 340 with the position information on the input image data IMA. The position information acquisition circuit 160 converts the panel-side light source position information into input-side light source position information based on the conversion table 167.

[0052] According to this embodiment, the mapping between the position information on the display panel of each light source and the position information on the input image data is stored in the memory circuit 165 as a conversion table 167 in advance, and the position information on the display panel of a faulty light source can be converted to the position information on the input image data using the conversion table 167.

[0053] In this embodiment, the fault information acquisition circuit 150 acquires at least one of the open or short information of the light-emitting elements of each light source 332 as fault information.

[0054] According to this embodiment, information regarding the input side light source position of the faulty light source, along with information on whether the fault in the faulty light source is an open or short circuit in the light-emitting element, is transmitted to the host. This allows the host to take appropriate action according to the type of fault.

[0055] Figure 6 shows an example where the area illuminated by a light source on a display panel is used as light source position information. The position information acquisition circuit 160 uses the area on the display panel corresponding to the faulty light source as the panel-side light source position information. If the area is a rectangular region, for example, the coordinates corresponding to the four vertices of the rectangular region, or the coordinates of each pixel contained within the rectangular region, become the panel-side light source position information. The position information acquisition circuit 160 converts these coordinates on the display panel into coordinates on the input image data IMA to obtain the area on the input image data IMA corresponding to the area on the display panel. This area on the input image data IMA becomes the input-side light source position information.

[0056] In this embodiment, the position information acquisition circuit 160 receives coordinate information specifying the area corresponding to the faulty light source among multiple areas as panel-side light source position information. The position information acquisition circuit 160 performs inverse distortion correction on this coordinate information to obtain input-side light source position information.

[0057] According to this embodiment, the area on the display panel 340 corresponding to the faulty light source is converted to an area on the input image data IMA by inverse distortion correction. As a result, coordinate information specifying the area corresponding to the faulty light source on the input image data IMA is output to the host as input light source position information.

[0058] In the example in Figure 6, the area corresponding to the faulty light source is a rectangular region. The coordinate information specifying this area consists of the coordinates corresponding to the four vertices of the rectangular region, or the coordinates of each pixel contained within the rectangular region. However, the area corresponding to the faulty light source is not limited to a rectangular region. In the example in Figure 3, the inverse distortion correction for the coordinate information specifying the area corresponds to a coordinate transformation using the transformation table 167. However, the inverse distortion correction for the coordinate information specifying the area can be performed using any coordinate transformation method, as long as the position coordinates (x,y) on the display panel 340 can be converted to the position coordinates (u,v) of the input image data IMA.

[0059] Figure 7 shows an example where the margin area on the input image data IMA is used as light source position information. The position information acquisition circuit 160 converts the center coordinates (x,y) on the display panel of the faulty light source to coordinates (u,v) on the input image data IMA. The position information acquisition circuit 160 sets a margin area of ​​a predetermined size centered on the obtained coordinates (u,v). This margin area becomes the input side light source position information. If the margin area is a rectangular area, for example, the coordinates corresponding to the four vertices of the rectangular area, or the coordinates of each pixel contained in the rectangular area, become the input side light source position information.

[0060] Figure 8 illustrates the distortion correction error detection process. As shown in the upper right panel, assume that an image error occurs in a certain area of ​​the output image data IMB after distortion correction. An image error is an image data that differs from the output image data IMB when distortion correction is processed correctly. As shown in the lower left panel, the inverse distortion correction circuit 120 performs inverse distortion correction on the output image data IMB to obtain the inverse distortion corrected image data IMC. The distortion correction error detection circuit 140 detects the image error region by comparing the input image data IMA with the inverse distortion corrected image data IMC. Since the image error region is mapped to the input region by inverse distortion correction, it is possible to detect which region on the input side has an image error. This image error region detected on the input side becomes the distortion correction error location information.

[0061] In this embodiment, the circuit device 100 includes an inverse distortion correction circuit 120 and a distortion correction error detection circuit 140. The inverse distortion correction circuit 120 converts the output image data IMB to inverse distortion correction image data IMC by performing inverse distortion correction of the distortion correction. The distortion correction error detection circuit 140 detects a distortion correction error by comparing the input image data IMA and the inverse distortion correction image data IMC. The position information acquisition circuit 160 acquires distortion correction error position information, which is the position information where a distortion correction error was detected on the input image data IMA. The host interface circuit 191 outputs the distortion correction error position information and the input side light source position information to the host.

[0062] According to this embodiment, if an image error occurs in the output image data (IMB) after distortion correction, the image error region in the input image data (IMA) corresponding to the image error region in the output image data (IMB) can be detected. By transmitting distortion correction error location information indicating this image error region to the host, the host can address the distortion correction error. Furthermore, by transmitting input-side light source location information of the faulty light source and distortion correction error location information to the host, the host can perform appropriate actions according to various fault or image error situations.

[0063] The circuit device of this embodiment described above is used in a display device. The display device includes a display panel and a backlight having multiple light sources. Each of the multiple light sources is provided corresponding to each of the multiple areas of the display panel. The circuit device includes a distortion correction circuit, a fault information acquisition circuit, a position information acquisition circuit, and a host interface circuit. The distortion correction circuit performs distortion correction on the input image data and outputs output image data after distortion correction. The fault information acquisition circuit acquires fault information for each light source. The position information acquisition circuit converts the panel-side light source position information on the display panel, which indicates the fault light source indicated by the fault information, into input-side light source position information on the input image data. The host interface circuit outputs the input-side light source position information to the host.

[0064] According to this embodiment, a backlight malfunction can be notified to the host. Furthermore, the panel-side light source position information on the display panel of the faulty light source is converted into input-side light source position information on the input image data, thereby notifying the host of the faulty light source position information that takes into account mapping in distortion correction. Based on this position information, the host can perform processing to address the light source malfunction in the input image data.

[0065] In this embodiment, the circuit device may also include a light source interface circuit that performs interface processing with a light source driver that drives multiple light sources. The fault information acquisition circuit may acquire fault information via the light source interface circuit.

[0066] According to this embodiment, the fault information acquisition circuit can acquire fault information for each light source detected by the light source driver via the light source interface circuit. Then, the position information acquisition circuit can acquire the input side light source position information of the faulty light source based on that fault information.

[0067] In this embodiment, the position information acquisition circuit may receive the position coordinates of the faulty light source on the display panel as panel-side light source position information, and perform inverse distortion correction on the position coordinates to obtain input-side light source position information.

[0068] According to this embodiment, the position coordinates of the faulty light source on the display panel are converted into the position coordinates of the input image data by inverse distortion correction. As a result, the position coordinates of the faulty light source on the input image data are output to the host as input light source position information.

[0069] In this embodiment, the position information acquisition circuit may receive coordinate information specifying the area corresponding to the faulty light source among multiple areas as panel-side light source position information, and perform inverse distortion correction on the coordinate information to obtain input-side light source position information.

[0070] According to this embodiment, the area on the display panel corresponding to the faulty light source is converted into an area of ​​the input image data by inverse distortion correction. As a result, coordinate information specifying the area corresponding to the faulty light source on the input image data is output to the host as input light source position information.

[0071] In this embodiment, the circuit device may also include a memory circuit. The memory circuit may store a conversion table that associates the position information of each light source on the display panel with the position information on the input image data. The position information acquisition circuit may convert the panel-side light source position information into input-side light source position information based on the conversion table.

[0072] According to this embodiment, the position information on the display panel of each light source is mapped to the position information on the input image data and stored in the memory circuit as a conversion table in advance. Using this conversion table, the position information on the display panel of a faulty light source can be converted to the position information on the input image data.

[0073] In this embodiment, the fault information acquisition circuit may acquire at least one of the open or short-circuit information of the light-emitting elements of each light source as fault information.

[0074] According to this embodiment, information regarding the input side light source position of the faulty light source, along with information on whether the fault in the faulty light source is an open or short circuit in the light-emitting element, is transmitted to the host. This allows the host to take appropriate action according to the type of fault.

[0075] In this embodiment, the circuit device may also include an inverse distortion correction circuit and a distortion correction error detection circuit. The inverse distortion correction circuit may convert the output image data into inverse distortion correction image data by performing inverse distortion correction of the distortion correction. The distortion correction error detection circuit may detect distortion correction errors by comparing the input image data with the inverse distortion correction image data. The position information acquisition circuit may acquire distortion correction error position information, which is the position information where a distortion correction error was detected on the input image data. The host interface circuit may output the distortion correction error position information and the input light source position information to the host.

[0076] According to this embodiment, if an image error occurs in the output image data after distortion correction, the image error region in the input image data corresponding to the image error region in the output image data can be detected. By transmitting the input light source position information of the faulty light source and the distortion correction error position information to the host, the host can take appropriate action according to various fault or image error situations.

[0077] Furthermore, the head-up display device of this embodiment includes a circuit device as described in any of the above, a display panel that displays an image based on output image data, a backlight, and a projection optical system that projects the image displayed on the display panel.

[0078] Although this embodiment has been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novelty and effects of this disclosure. Therefore, all such modifications are included within the scope of this disclosure. For example, any term that appears at least once in the specification or drawings together with a broader or synonymous term may be replaced with that different term anywhere in the specification or drawings. Furthermore, all combinations of this embodiment and its modifications are also included within the scope of this disclosure. In addition, the configuration and operation of the circuit device, display unit, processing unit, display device, and head-up display device are not limited to those described in this embodiment, and various modifications are possible. [Explanation of Symbols]

[0079] 10…Eye, 20…Screen, 50…Head-up display device, 52…Projection optical system, 100…Circuit device, 105…Input circuit, 110…Distortion correction circuit, 120…Inverse distortion correction circuit, 130…Output circuit, 140…Distortion correction error detection circuit, 150…Fault information acquisition circuit, 160…Position information acquisition circuit, 165…Memory circuit, 167…Conversion table, 170…Error processing circuit, 180…Light source control circuit, 191…Host interface circuit, 192…Light source interface circuit, 200…Processing unit, 300…Display unit, 310…Processing unit, 320…Light source driver, 330…Backlight, 332…Light source, 333…Area, 340…Display panel, IMA…Input image data, IMB…Output image data, IMC…Inverse distortion corrected image data, LE…Fault information

Claims

1. A circuit device used in a display device, which includes a display panel and a backlight having multiple light sources, wherein each of the multiple light sources is provided corresponding to each of the multiple areas of the display panel, An input circuit that receives input image data from the host, A distortion correction circuit that performs distortion correction on the input image data and outputs distortion-corrected output image data, A light source interface circuit that performs interface processing with a light source driver that drives the plurality of light sources, A fault information acquisition circuit that acquires fault information for each of the light sources via the light source interface circuit, A position information acquisition circuit that converts the panel-side light source position information of the fault light source indicated by the fault information on the display panel into input-side light source position information on the input image data, A host interface circuit that outputs the input side light source position information to the host, Includes, The aforementioned location information acquisition circuit is A circuit device characterized in that the position coordinates of the faulty light source on the display panel are input as the panel-side light source position information, and the inverse distortion correction of the distortion correction is performed on the position coordinates to obtain the position coordinates of the faulty light source on the input image data as the input-side light source position information.

2. A circuit device used in a display device, which includes a display panel and a backlight having multiple light sources, wherein each of the multiple light sources is provided corresponding to each of the multiple areas of the display panel, An input circuit that receives input image data from the host, A distortion correction circuit that performs distortion correction on the input image data and outputs distortion-corrected output image data, A light source interface circuit that performs interface processing with a light source driver that drives the plurality of light sources, A fault information acquisition circuit that acquires fault information for each of the light sources via the light source interface circuit, A position information acquisition circuit that converts the panel-side light source position information of the fault light source indicated by the fault information on the display panel into input-side light source position information on the input image data, A host interface circuit that outputs the input side light source position information to the host, Includes, The aforementioned location information acquisition circuit is A circuit device characterized in that coordinate information specifying the area corresponding to the faulty light source among the plurality of areas is input as the panel-side light source position information, and inverse distortion correction of the distortion correction is performed on the coordinate information to obtain coordinate information specifying the area on the input image data corresponding to the faulty light source as the input-side light source position information.

3. In the circuit device described in claim 1 or 2, The system includes a storage circuit that stores a conversion table that associates the position information of each light source on the display panel with the position information on the input image data. The aforementioned location information acquisition circuit is A circuit device characterized by converting the panel-side light source position information into the input-side light source position information based on the conversion table.

4. In a circuit device according to any one of claims 1 to 3, The fault information acquisition circuit is, A circuit device characterized by acquiring at least one of open-circuit information or short-circuit information of the light-emitting elements of each of the aforementioned light sources as fault information.

5. In a circuit device according to any one of claims 1 to 4, An inverse distortion correction circuit that converts the output image data into image data after inverse distortion correction by inverse distortion correction of the aforementioned distortion correction, A distortion correction error detection circuit detects a distortion correction error by comparing the input image data with the inverse distortion-corrected image data, Includes, The aforementioned location information acquisition circuit is The distortion correction error location information, which is the location information where the distortion correction error was detected on the input image data, is acquired. The aforementioned host interface circuit is A circuit device characterized by outputting the distortion correction error position information and the input side light source position information to the host.

6. A circuit device as described in any one of claims 1 to 5, The display panel that displays an image based on the output image data, The aforementioned backlight and, A projection optical system that projects the image displayed on the display panel, A head-up display device characterized by including the following:

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