Circuit arrangement and head-up display device

Abstract

Provided are a circuit device and a head-up display device. The circuit device is for a head-up display device including a display panel and a backlight device having a plurality of light emitting elements. The circuit device includes a distortion correction circuit and an image analysis circuit. The distortion correction circuit performs distortion correction on input image data, and outputs output image data that is distortion-corrected. The image analysis circuit performs analysis on analysis target image data that is the input image data or the output image data, and performs a backlight control process that causes light emitting elements corresponding to display regions that become transparent when projected by the head-up display device among a plurality of display regions in the display panel corresponding to the plurality of light emitting elements to become an extinguished state, based on a result of the analysis.

Description

TECHNICAL FIELD

[0001] The present application relates to a circuit device and a head-up display device or the like. BACKGROUND

[0002] A head-up display device is known in which an image is projected on a transparent screen, and a user who views the screen visually recognizes a virtual image. A display device for a vehicle is disclosed in Patent Literature 1, which includes a liquid crystal display, a back light source provided on the back of the liquid crystal display, and a reflection plate that reflects light that has passed through the liquid crystal display toward a windshield.

[0003] Patent Literature 1: Japanese Patent Application Laid-Open No. 2001-117071

[0004] From the viewpoint of a user who views the head-up display device, a virtual image projected by the head-up display device is seen overlapping with the real world as seen through the screen. An area in the display region of the head-up display device where no display object is displayed becomes a state where the user sees it as transparent, i.e., the real world as it is. However, on the nature of the head-up display device that projects light onto the screen, there is a problem that some light is projected also in the transparent area where no display object is displayed, and the area that should originally be transparent appears white. SUMMARY

[0005] One embodiment of the present disclosure relates to a circuit device for a head-up display device that includes a display panel and a back light device having a plurality of light emitting elements, the circuit device including: a distortion correction circuit that performs distortion correction on input image data, and outputs output image data after the distortion correction; and an image analysis circuit that performs a back light control process in which analysis is performed on analysis target image data that is the input image data or the output image data, and based on a result of the analysis, causes a light emitting element corresponding to a display region that is a display region among a plurality of display regions of the display panel corresponding to the plurality of light emitting elements that becomes a transparent color when projected by the head-up display device to be in an off state.

[0006] In addition, another embodiment of the present disclosure relates to a head-up display device that includes the above-described circuit device, the display panel, and the back light device. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is an example of HUD display in a conventional head-up display device.

[0008] Figure 2 is a first configuration example of a circuit device and a head-up display device.

[0009] Figure 3 are plan and side views of a backlight device and a display panel.

[0010] Figure 4 are examples of display regions corresponding to light emitting elements.

[0011] Figure 5 is a display example in the present embodiment.

[0012] Figure 6 is a first detailed configuration example of the circuit device.

[0013] Figure 7 is a diagram illustrating the operation of the circuit device in the first detailed configuration example.

[0014] Figure 8 is a timing chart in the case where backlight control is performed at the rear stage of the circuit device without using the present embodiment.

[0015] Figure 9 is a timing chart in the case where backlight control is performed at the rear stage of the circuit device when the present embodiment is used.

[0016] Figure 10 is a second configuration example of the circuit device and the head-up display device.

[0017] Figure 11 is a second detailed configuration example of the circuit device.

[0018] Figure 12 is a diagram illustrating the operation of the circuit device in the second detailed configuration example.

[0019] Figure 13 is a third configuration example of the circuit device.

[0020] Figure 14 is a flowchart showing the processing steps of the HUD system including the circuit device of the third configuration example.

[0021] Figure 15 is a diagram illustrating dimming of each light emitting element.

[0022] Label Explanation

[0023] 1: image; 2: display object; 5: display region; 6: display object; 10: backlight device; 20: display panel; 30: display device; 50: head-up display device; 100: circuit device; 110: distortion correction circuit; 112: coordinate counter; 113: correction coordinate conversion circuit; 114: interpolation circuit; 115: storage circuit; 116: correction coordinate counter; 119: distortion correction section; 120: image analysis circuit; 121: coordinate conversion circuit; 122: determination circuit; 130: output circuit; 140: interface circuit; 150: brightness control value calculation circuit; 160: interface circuit; 200: processing device; AR: display region; BHI: brightness deviation correction amount; CTL: control signal; CTLB: control signal; GZA: reference coordinate; GZA2: pixel coordinate; GZB: pixel coordinate; GZB2: movement destination coordinate; IMA: input image data; IMB: output image data; KDI: brightness adjustment amount; LS: light emitting element. DETAILED DESCRIPTION

[0024] Hereinafter, a preferred embodiment of the present disclosure will be described in detail. In addition, the present embodiment described below is not intended to unduly limit the content recited in the claims, and all the structures described in the present embodiment are not necessarily essential structural elements.

[0025] 1. About HUD display

[0026] An example of HUD display in a conventional head-up display device is shown in the upper stage of FIG. 1. In addition, here, an image at the time of projection is assumed to ignore image distortion, but the problem points of the HUD display described below are the same even in the case where image distortion is present. Figure 1 An example of an image displayed on a liquid crystal panel of the HUD is shown in the upper stage of FIG. 1. Several display objects 2 are included in the image 1. In the liquid crystal panel, the pixels of the region in which the display object 2 is displayed become a state in which light is transmitted according to the gray scale value, but the pixels of the region other than the display object 2 become a state in which light is not transmitted.

[0027] Figure 1 The lower stage of FIG. 1 is an example of display at the time when the head-up display device projects the image of the upper stage to the field of view of the user. The backlight device emits light, the light transmitted through the liquid crystal panel is reflected by the reflection plate toward the screen, and the light reflected by the screen is incident to the eyes of the user, thereby projecting the display object 6 corresponding to the virtual image of the display object 2 in the field of view of the user. The display object 6 of the virtual image overlaps with the real world as a background of the HUD display.

[0028] Figure 1

[0029] ​​At this time, the area in the liquid crystal panel in which the display 6 of the virtual image is not displayed in the display area 5 of the HUD is in a non-transmissive state, and thus the area originally in the transparent color in which nothing is displayed should be seen as the background as it is. However, in the liquid crystal panel, the light of the backlight device slightly transmits even in the non-transmissive area, and thus in the HUD display, the area originally in the transparent color appears slightly brighter than the surroundings. For example, in a dark environment such as at night or in a tunnel, the area in the display area 5 in which the display 6 of the virtual image is not displayed appears white, and thus the visibility of the background overlapping the area can be reduced.

[0030] 2. First configuration example

[0031] Figure 2 is a first configuration example of the circuit device 100 and the head-up display device 50 in the present embodiment. The head-up display device 50 includes the display device 30 and the circuit device 100. Further, the head-up display device 50 includes an optical system such as a reflection plate, but the illustration thereof is omitted in Figure 2 .

[0032] The display device 30 includes the backlight device 10 and the display panel 20. Figure 3 indicates a plan view and a side view of the backlight device 10 and the display panel 20.

[0033] The display panel 20 is a liquid crystal display panel in which pixels are arrayed. Hereinafter, a case in which the display panel 20 is a transmissive liquid crystal panel will be described as an example, but the display panel 20 can also be a reflective liquid crystal panel. In Figure 3 , the direction parallel to the horizontal scanning direction of the display panel 20 is set as the x direction, and the direction parallel to the vertical scanning direction is set as the y direction. In addition, the direction orthogonal to the x direction and the y direction and facing the display panel 20 from the backlight device 10 is set as the z direction.

[0034] The backlight device 10 includes a plurality of light emitting elements LS arranged on a plane parallel to the xy plane. The plurality of light emitting elements LS are arranged in substantially the same area as the pixel array of the display panel 20 when viewed from above. The plurality of light emitting elements LS are arranged in an array such that, in a case in which all of the plurality of light emitting elements LS are lit, light is irradiated to the entire surface of the pixel array of the display panel 20. Figure 3 indicates an example in which the plurality of light emitting elements LS are arranged in 9 rows and 16 columns. The light emitting elements LS of each row are arranged in parallel to the x direction, and the light emitting elements LS of each column are arranged in parallel to the y direction. However, the arrangement of the light emitting elements LS is not limited to this. Figure 3 is an example of the arrangement of the light emitting elements, and the arrangement of the light emitting elements is not limited to this.

[0035] Each light emitting element LS of the backlight device 10 is a light emitting element such as an LED that can be independently controlled to be turned on or turned off. The LED is an abbreviation of Light Emitting Diode. Further, hereinafter, turning on of the light emitting element is also referred to as lighting, and turning off of the light emitting element is also referred to as extinguishing. Each light emitting element LS can be configured to be capable of independently performing dimming, and each light emitting element LS can be independently controlled to be turned on or turned off using the dimming function thereof.

[0036] Figure 2 The circuit device 100 illustrated includes a distortion correction circuit 110, an image analysis circuit 120, and an output circuit 130. The circuit device 100 is, for example, an integrated circuit device in which a plurality of circuit elements are integrated on a semiconductor substrate.

[0037] 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 output image data IMB as corrected image data. The distortion correction refers to image correction for performing HUD display with no distortion or reduced distortion by applying, to an image, an image distortion opposite to an image distortion when an image displayed on the display panel 20 is projected. The image distortion based on projection includes an image distortion caused by a curved surface of a screen, an image distortion caused by a HUD optical system, or both.

[0038] The distortion correction circuit 110 includes a coordinate counter 112 that counts the pixel coordinates GZB in the output image data IMB. The "counting the pixel coordinates" refers to, for example, when the image size is 1920 x 1080 pixels, sequentially outputting the coordinates representing the positions of the pixels as (0, 0), (1, 0),..., (1919, 0), (0, 1), (1, 1),..., (1919, 1),..., (0, 1079), (1, 1079),..., (1919, 1079).

[0039] The distortion correction circuit 110 corresponds to a reverse warp engine, and the coordinate counter 112 is a coordinate counter for the reverse warp. The reverse warp refers to a warp process of coordinate-transforming the pixel coordinates on the output image data IMB into reference coordinates corresponding thereto, and deriving the pixel data of the output image data IMB from the pixel data of the input image data IMA in the reference coordinates. The coordinate transformation is defined by a warp parameter. The warp parameter is a table that establishes a correspondence between the pixel coordinates and the reference coordinates, a table that represents an amount of movement between the pixel coordinates and the reference coordinates, or a coefficient of a polynomial that establishes a correspondence between the pixel coordinates and the reference coordinates, or the like.

[0040] The output circuit 130 sends the output image data IMB to the display device 30. The output circuit 130 can be a transmitting circuit for various communication interfaces, such as LVDS, DVI, a display port, GMSL, or GVIF. LVDS stands for Low Voltage Differential Signaling, DVI for Digital Visual Interface, GMSL for Gigabit Multimedia Serial Link, and GVIF for Gigabit Video Interface.

[0041] Additionally, although not illustrated, a display controller and a display driver are provided between the output circuit 130 and the display panel 20. The display controller and display driver are composed of one or more integrated circuit devices that are different from the integrated circuit devices constituting the distortion correction circuit 110. Alternatively, the integrated circuit device constituting the distortion correction circuit 110 may also have the functions of a display controller built in, or it may have the functions of both a display controller and a display driver built in.

[0042] The image analysis circuit 120 performs image analysis in parallel with distortion correction and outputs a control signal CTL that independently controls each light-emitting element LS of the backlight device 10 to be turned on or off. Specifically, the image analysis circuit 120 outputs the control signal CTL based on the pixel coordinates GZB output by the coordinate counter 112 and the pixel data of the pixel coordinates GZB in the output image data IMB output by the distortion correction circuit 110. Hereinafter, using Figure 4 as well as Figure 5 Please provide an explanation.

[0043] Figure 4 An example representing the display area corresponding to the light-emitting element LS. Figure 4 The display area ARa corresponding to the light-emitting element LSa and the display area ARb corresponding to the light-emitting element LSb on the display panel 20 are shown. Here, only the display area corresponding to two light-emitting elements is shown, but there are display areas corresponding to each light-emitting element.

[0044] The display area corresponding to the light emitting element refers to an area on the display panel 20 irradiated with light emitted from the light emitting element. That is, the image displayed in the display area is projected by light emitted from the light emitting element corresponding to the display area. A part of the display area corresponding to a certain light emitting element and a part of the display area corresponding to a light emitting element adjacent to the light emitting element can also overlap. As an example, in the case where the display area corresponding to each light emitting element is a rectangular area, the display area corresponding to each light emitting element can be specified by specifying information of a start point coordinate, a width, and a height. The information indicating the display area corresponding to each light emitting element is written, for example, from a processing device outside the circuit device 100 into a not-shown register or the like in the circuit device 100, or is stored in advance in a not-shown nonvolatile memory provided in the circuit device 100.

[0045] The image analysis circuit 120 determines the display area to which the pixel coordinate GZB output from the coordinate counter 112 belongs, and determines whether to turn off the light emitting element corresponding to the display area based on whether the pixel data of the pixel coordinate GZB is a transparent color in the HUD display. The transparent color refers to a color in which nothing is displayed in the HUD display and the background can be directly seen when the color displayed on the display panel 20 is projected by the HUD. Specifically, the HUD display should be transparent when the pixel of the display panel 20 blocks light, and thus a color that becomes black when displayed on the display panel 20 corresponds to the transparent color. Hereinafter, black in the image data is assumed to be the transparent color in the HUD display.

[0046] The image analysis circuit 120 turns off the light emitting element corresponding to the display area when all the pixel data in the display area is black, and turns on the light emitting element corresponding to the display area even when there is one pixel data that is not black in the display area. In the example of FIG. 6, the light emitting element LSa corresponding to the display area ARa overlapping the display object 2 is determined to be turned on, and the light emitting element LSb corresponding to the display area ARb not overlapping the display object 2 is determined to be turned off. In addition, the image analysis circuit 120 can also turn off the light emitting element corresponding to the display area when the pixel data that is not transparent in the display area is equal to or less than a prescribed number. The prescribed number is, for example, 1 to several tens or so. Figure 4

[0047] Figure 5 ​The upper drawing shows the on / off state of each light emitting element. The white circle shows the off light emitting element, and the black circle shows the on light emitting element. The middle drawing shows the display region AR projected by the light emitting element turned on in the upper drawing. The display region AR includes only the display object 2 and its periphery, and the region where the display object 2 is absent is hardly included in the display region AR. The lower drawing shows the HUD display when the image of the middle drawing is projected by the light emitting element turned on in the upper drawing. Since the light emitting element corresponding to the region where the display object 6 is present is turned on, and the light emitting element corresponding to the region where the display object 6 is absent is turned off, the display object 6 is displayed, and the region where the display object 6 is absent is hardly white but transparent, and becomes the state where the background is visible as it is.

[0048] The distortion correction circuit 110 and the image analysis circuit 120 are logic circuits. The distortion correction circuit 110 and the image analysis circuit 120 can be configured as separate circuits, or the distortion correction circuit 110 and the image analysis circuit 120 can be configured as an integrated circuit by automatic wiring or the like. In addition, part or all of these logic circuits can be implemented by a processor such as a DSP (Digital Signal Processor). In this case, a program or an instruction set in which the functions of each circuit are described is stored in a memory, and the functions of each circuit are implemented by the processor executing the program or the instruction set.

[0049] Figure 6 is a first detailed configuration example of the circuit device 100. The distortion correction circuit 110 includes a coordinate counter 112, a correction coordinate conversion circuit 113, an interpolation circuit 114, and a storage circuit 115. Figure 7 is a diagram illustrating the operation of the circuit device 100 in the first detailed configuration example.

[0050] The coordinate counter 112 outputs the pixel coordinates GZB = (x, y) on the output image data IMB. The correction coordinate conversion circuit 113 converts the pixel coordinates (x, y) into the coordinates on the input image data IMA, that is, the reference coordinates GZA = (u, v). The storage circuit 115 temporarily stores the input image data IMA and outputs the pixel data PXD of the reference coordinates (u, v). Specifically, the correction coordinate conversion circuit 113 converts the reference coordinates (u, v) into a read address, and the storage circuit 115 reads out the pixel data PXD of the reference coordinates (u, v) from the read address. More specifically, the correction coordinate conversion circuit 113 outputs the read addresses of a plurality of pixels around the reference coordinates (u, v), and the storage circuit 115 reads out the pixel data of the plurality of pixels. The interpolation circuit 114 calculates the pixel data of the pixel coordinates (x, y) in the output image data IMB by performing interpolation processing on the plurality of pixel data read out in correspondence with the reference coordinates (u, v).

[0051] The image analysis circuit 120 determines which display region the pixel coordinate (x, y) output from the coordinate counter 112 belongs to, with respect to the light emitting elements. The image analysis circuit 120 uses the determination result and the pixel data of the pixel coordinate (x, y) output from the interpolation circuit 114, and determines whether to turn off each light emitting element.

[0052] In the above embodiment, the circuit device 100 is used for the head-up display device 50. The head-up display device 50 includes the display panel 20 and the backlight device 10 having a plurality of light emitting elements LS. The circuit device 100 includes the distortion correction circuit 110 and the image analysis circuit 120. The distortion correction circuit 110 performs distortion correction on the input image data IMA, and outputs the output image data IMB after the distortion correction. The image analysis circuit 120 analyzes the analysis target image data which is the input image data IMA or the output image data IMB, and performs the backlight control process of turning off the light emitting element LS corresponding to the display region AR which becomes transparent when projected by the head-up display device 50, among the plurality of display regions AR in the display panel 20 corresponding to the plurality of light emitting elements LS, based on the analysis result.

[0053] In addition, although the example in which the image analysis circuit 120 analyzes the output image data IMB as the analysis target image data is described in the first configuration example, the image analysis circuit 120 can analyze the input image data IMA as the analysis target image data. With respect to this example, the second configuration example is described later.

[0054] According to the present embodiment, the display region which becomes transparent when projected by the HUD is determined by image analysis. Furthermore, the light emitting element LS corresponding to the display region which becomes transparent when projected by the HUD, among the plurality of light emitting elements LS provided to the backlight device 10, is turned off, and thus the display region is displayed as the original transparent region without whitening in the HUD display. Thus, even in a case where the background is dark such as at night or in a tunnel, the region in the HUD display where nothing is displayed becomes the original transparent region, and the visibility of the background is not reduced.

[0055] In addition, in the present embodiment, the image analysis circuit 120 analyzes whether the analysis target image data in each display region AR of the plurality of display regions is transparent data, and performs the backlight control process of turning off the light emitting element LS corresponding to the display region AR in which the analysis target image data is analyzed as transparent data.

[0056] According to the present embodiment, the image analysis circuit 120 is able to determine the display region AR that becomes transparent when projected by the head-up display device 50, among the plurality of display regions AR, by performing image analysis of whether the analysis target image data is data of a transparent color in each display region AR.

[0057] Further, in the present embodiment, the distortion correction circuit 110 includes a coordinate counter 112 that counts the pixel coordinates GZB of the analysis target image data. The image analysis circuit 120 determines the display region AR to which each pixel of the analysis target image data belongs, among the plurality of display regions AR, based on the pixel coordinates GZB output by the coordinate counter 112, and determines the display region AR that becomes transparent based on the determination result.

[0058] According to the present embodiment, the pixel coordinates GZB output by the coordinate counter 112 indicate the pixel coordinates of each pixel in the analysis target image data, and thus the image analysis circuit 120 is able to determine the display region AR to which each pixel of the analysis target image data belongs, among the plurality of display regions AR, based on the pixel coordinates GZB.

[0059] Further, in the present embodiment, the image analysis circuit 120 determines whether the pixel data belonging to each display region AR of the plurality of display regions is data of a transparent color, based on the pixel coordinates GZB output by the coordinate counter 112 and the pixel data of the analysis target image data at the pixel coordinates GZB, and thereby determines whether each display region AR is a display region AR that becomes transparent.

[0060] According to the present embodiment, the image analysis circuit 120 is able to determine the display region AR to which the pixel coordinates GZB belong and whether the pixel data of the pixel coordinates GZB is data of a transparent color. Thereby, the image analysis circuit 120 is able to determine whether each display region AR is a display region that becomes transparent when displayed by the HUD.

[0061] Further, according to the present embodiment, the analysis target image data is either the input image data IMA input to the distortion correction circuit 110 or the output image data IMB output by the distortion correction circuit 110, and the pixel coordinates output by the coordinate counter 112 included in the distortion correction circuit 110 are used for image analysis. Thereby, the distortion correction circuit 110 performs distortion correction, and in parallel therewith, the image analysis circuit 120 is able to perform backlight control by image analysis, and thus is able to eliminate or simplify the time lag adjustment of the HUD display and the backlight control. Hereinafter, the case in which the analysis target image data is the output image data IMB output by the distortion correction circuit 110 will be described. Figure 8 and Figure 9 will be described.

[0062] Figure 8 A timing chart in the case in which backlight control is performed at a stage subsequent to the circuit device 100 without using the present embodiment is shown. Further,Figure 8 is a diagram schematically illustrating the timing of the backlight control, and does not necessarily represent strict timing. As shown in Figure 8 , in the path of displaying an image on the display panel 20, the distortion correction circuit 110 sequentially outputs the output image data IMB per line, and the output image data IMB per line is sequentially displayed on the display panel 20. On the other hand, in the path of the backlight control, for example, a frame memory is provided at the rear stage of the circuit device 100, and the output image data IMB of 1 frame is buffered, and the output image data IMB is analyzed to perform the backlight control. Therefore, the timing of the image display and the timing of the backlight control are, for example, shifted by 1 frame or more.

[0063] Figure 9 a timing chart in a case where the backlight control is performed at the rear stage of the circuit device 100 when the present embodiment is used. Further, Figure 9 is a diagram schematically illustrating the timing of the backlight control, and does not necessarily represent strict timing. As shown in Figure 9 , in the path of displaying an image on the display panel 20, the distortion correction circuit 110 sequentially outputs the output image data IMB per line, and the output image data IMB per line is sequentially displayed on the display panel 20. This is the same as Figure 8 . In the path of the backlight control, by performing the image analysis in parallel with the distortion correction, it is possible to make the timing of the image display and the timing of the backlight control closer than Figure 8 . Thus, compared with Figure 8 , timing adjustment is not required or is simplified. In addition, in the second structural example described later, this point that the image analysis is performed in parallel with the distortion correction is the same, and as with the first structural example, compared with Figure 8 , timing adjustment is not required and becomes simple.

[0064] In addition, in the present embodiment, the analysis target image data is the output image data IMB. The distortion correction circuit 110 transforms the pixel coordinates GZB = (x, y) output by the coordinate counter 112 into reference coordinates GZA = (u, v) on the input image data IMA, and outputs the pixel data of the output image data IMB at the pixel coordinates (x, y) based on the pixel data of the input image data IMA at the reference coordinates (u, v), thereby performing the distortion correction. The image analysis circuit 120 judges which one of the plurality of display regions AR the pixel coordinates (x, y) output by the coordinate counter 112 belong to, and judges whether or not the display region AR to which the pixel coordinates (x, y) are judged to belong is a display region AR that becomes a transparent color based on the pixel data of the output image data IMB at the pixel coordinates (x, y) output by the distortion correction circuit 110.

[0065] According to the present embodiment, based on the pixel coordinates (x, y) output by the coordinate counter 112 used in the distortion correction and the pixel data of the output image data IMB output by the distortion correction circuit 110 corresponding to the pixel coordinates (x, y), the backlight control based on the image analysis is performed. Thereby, since the distortion correction and the backlight control based on the image analysis are processed in parallel, the time lag adjustment of the HUD display and the backlight control can be omitted or simplified as described above.

[0066] 3. Second Configuration Example

[0067] Figure 10 is a second configuration example of the circuit device 100 and the head-up display device 50. Further, the same reference numerals are attached to the constituent elements already explained, and the explanation about the constituent elements is appropriately omitted.

[0068] In the second configuration example, the coordinate counter 112 counts the pixel coordinates GZA2 in the input image data IMA. The image analysis circuit 120 outputs the control signal CTL that independently controls each light emitting element LS of the backlight device 10 to be turned on or off by performing the image analysis in parallel with the distortion correction. Specifically, the image analysis circuit 120 outputs the control signal CTL based on the pixel coordinates GZA2 output by the coordinate counter 112 and the pixel data of the pixel coordinates GZA2 in the input image data IMA.

[0069] The distortion correction circuit 110 corresponds to a reverse warping engine. The pixel data of the input image data IMA is sequentially input to the reverse warping engine, and the coordinate counter 112 counts the pixel coordinates of the sequentially input pixel data. The image analysis circuit 120 transforms the pixel coordinates GZA2 into the movement destination coordinates in the output image data IMB, and determines whether to turn off each light emitting element based on the movement destination coordinates and the pixel data of the pixel coordinates GZA2 in the input image data IMA.

[0070] Figure 11 is a second detailed configuration example of the circuit device 100. The distortion correction circuit 110 includes the coordinate counter 112 and a distortion correction section 119. The distortion correction section 119 includes a correction coordinate transformation circuit 113, an interpolation circuit 114, a storage circuit 115, and a correction coordinate counter 116. The image analysis circuit 120 includes a coordinate transformation circuit 121 and a determination circuit 122. Figure 12 is a diagram illustrating the operation of the circuit device 100 in the second detailed configuration example.

[0071] The storage circuit 115 temporarily stores the input image data IMA. The coordinate counter 112 counts the pixel coordinates GZA2 = (u2, v2) of the pixel data written in the storage circuit 115.

[0072] The correction coordinate counter 116 outputs the pixel coordinates GZB = (x, y) on the output image data IMB. The correction coordinate conversion circuit 113 converts the pixel coordinates (x, y) into the coordinates on the input image data IMA, that is, the reference coordinates GZA = (u, v). Let this conversion be a first coordinate conversion. The storage circuit 115 outputs the pixel data PXD of the reference coordinates (u, v). Specifically, the correction coordinate conversion circuit 113 outputs the read addresses of a plurality of pixels around the reference coordinates (u, v), and the storage circuit 115 reads out the pixel data of the plurality of pixels. The interpolation circuit 114 obtains the pixel data of the pixel coordinates (x, y) in the output image data IMB by performing an interpolation process on the plurality of pixel data read out in correspondence with the reference coordinates (u, v).

[0073] The coordinate conversion circuit 121 of the image analysis circuit 120 converts the pixel coordinates (u2, v2) output by the coordinate counter 112 into the coordinates on the output image data IMB, that is, the movement destination coordinates GZB2 = (x2, y2). Let this conversion be a second coordinate conversion. The second coordinate conversion is an inverse conversion of the first coordinate conversion. The determination circuit 122 determines to which display region the movement destination coordinates (x2, y2) output by the coordinate conversion circuit 121 belong. The determination circuit 122 uses the determination result and the pixel data of the pixel coordinates (u2, v2) in the input image data IMA to determine whether to extinguish each light emitting element.

[0074] The movement destination coordinates (x2, y2) indicate where the pixel data of the pixel coordinates (u2, v2) in the input image data IMA is moved to in the output image data IMB. The determination circuit 122 can determine to which display region the pixel data of the pixel coordinates (u2, v2) in the input image data IMA is moved to by performing the region determination using the movement destination coordinates (x2, y2).

[0075] In the above embodiment, the analysis target image data is the input image data IMA. The image analysis circuit 120 includes the coordinate conversion circuit 121 and the determination circuit 122. The coordinate conversion circuit 121 converts the pixel coordinates GZA2 = (u2, v2) output by the coordinate counter 112 into the movement destination coordinates GZB2 = (x2, y2) on the output image data IMB. The determination circuit 122 determines which display region AR among the plurality of display regions AR the movement destination coordinates (x2, y2) belong to, and determines whether the display region AR to which the movement destination coordinates (x2, y2) are judged to belong is a display region AR that becomes a transparent color based on the pixel data of the input image data IMA at the pixel coordinates (u2, v2).

[0076] According to the present embodiment, the pixel coordinates GZA2=(u2, v2) of the input image data IMA input to the distortion correction circuit 110 are counted, and the pixel coordinates (u2, v2) are converted into the movement destination coordinates (x2, y2) on the output image data IMB. Then, based on the movement destination coordinates (x2, y2) and the pixel data of the pixel coordinates (u2, v2) in the input image data IMA, the backlight control based on the image analysis is performed. Thus, since the distortion correction and the backlight control based on the image analysis are processed in parallel, it is possible to perform the HUD display and the backlight control without requiring or simplifying the time lag adjustment as in Figure 8 and Figure 9 above.

[0077] Further, in the present embodiment, the distortion correction circuit 110 includes the correction-use coordinate counter 116 that counts the coordinates on the output image data IMB, and performs the distortion correction based on the first coordinate conversion that converts the coordinates output from the correction-use coordinate counter 116 into the reference coordinates GZA on the input image data IMA. The coordinate conversion circuit 121 obtains the movement destination coordinates GZB2=(x2, y2) by performing the second coordinate conversion that is the inverse conversion of the first coordinate conversion on the pixel coordinates GZA2=(u2, v2) output from the coordinate counter 112.

[0078] According to the present embodiment, in addition to the correction-use coordinate counter 116 for the inverse warping, the coordinate counter 112 that counts the pixel coordinates GZA2=(u2, v2) of the input image data IMA and the coordinate conversion circuit 121 that converts the pixel coordinates (u2, v2) into the movement destination coordinates GZB2=(x2, y2) on the output image data IMB are provided. Thus, it is possible to determine whether the display region AR becomes the transparent color in the HUD display using the input image data IMA as the analysis target image data.

[0079] 4. Third Structural Example

[0080] Figure 13 is a third structural example of the circuit device 100. The circuit device 100 includes the distortion correction circuit 110, the image analysis circuit 120, the output circuit 130, the interface circuit 140, the luminance control value calculation circuit 150, and the interface circuit 160. Further, the same reference numerals are attached to the constituent elements already explained, and the explanation about the constituent elements is appropriately omitted. In Figure 13 , an example in which the interface circuit 140, the luminance control value calculation circuit 150, and the interface circuit 160 are combined to the first structural example is shown, but the interface circuit 140, the luminance control value calculation circuit 150, and the interface circuit 160 can also be combined to the second structural example.

[0081] Figure 14 is a flowchart showing processing steps of the HUD system including the circuit device 100 of the 3rd configuration example.

[0082] In step S1, the illuminance sensor measures the illuminance of the outside environment. The illuminance of the outside environment is the illuminance of the real world which the user visually confirms together with the HUD display. In step S2, the processing device 200 calculates the luminance adjustment amount KDI of the entire screen on the basis of the measured value of the illuminance sensor. The processing device 200 is a so-called SoC, for example, a processor such as a CPU or a microcomputer. The SoC is an abbreviation of System on Chip. The CPU is an abbreviation of Central Processing Unit.

[0083] In step S3, the processing device 200 transmits the luminance adjustment amount KDI to the interface circuit 140 of the circuit device 100. The interface circuit 140 is, for example, a serial interface of the SPI standard or the I2C standard. The SPI is an abbreviation of Serial Peripheral Interface, and the I2C is an abbreviation of Inter-Integrated Circuit. In addition, the processing device 200 transmits the luminance deviation correction amount BHI of each light emitting element to the interface circuit 140.

[0084] In step S4, the luminance control value calculation circuit 150 implements dimming of each light emitting element on the basis of taking into account the luminance adjustment amount KDI of the entire screen. Figure 15 A diagram showing dimming of each light emitting element is shown. Here, the backlight device 10 has 3 x 3 light emitting elements.

[0085] The luminance adjustment amount KDI of the entire screen is set to one for all light emitting elements, and Figure 15 KDI = 0.5 in the example. The luminance deviation correction amount BHI is set to one correction amount for each light emitting element. The distortion correction circuit 110 performs distortion correction on the input image data IMA received from the processing device 200, and the image analysis circuit 120 outputs a control signal CTL which controls each light emitting element to be turned on or off by performing image analysis in parallel with the distortion correction. Figure 15 In the example, only the off is shown, and the blank column means the on. The luminance control value calculation circuit 150 obtains the luminance control value of each light emitting element by multiplying the luminance adjustment amount KDI of the entire screen by the luminance deviation correction amount BHI. The luminance control value calculation circuit 150 sets the luminance control value of the light emitting element for which the off is instructed by the control signal CTL to zero, and outputs it as the control signal CTLB.

[0086] In step S5, the interface circuit 160 outputs the control signal CTLB to the backlight device 10, and the backlight device 10 performs dimming of each light emitting element based on the control signal CTLB. The light emitting element whose brightness control value is zero is turned off, and the light emitting element whose brightness control value is larger than zero emits light at a brightness controlled by the brightness control value. Since the brightness deviation is corrected by the brightness deviation correction amount BHI, the light emitting element that is turned on emits light at the same brightness as each other.

[0087] In the above embodiment, the circuit device 100 includes the brightness control value calculation circuit 150 and the interface circuit 160. The brightness control value calculation circuit 150 changes the backlight control signal received from the external processing device 200 based on the result of the backlight control processing from the image analysis circuit 120, thereby calculating the brightness control value for each light emitting element LS of the plurality of light emitting elements. The interface circuit 160 outputs the brightness control value for each light emitting element LS to the backlight device 10. In the 3rd configuration example, the backlight control signal is the brightness adjustment amount KDI and the brightness deviation correction amount BHI of the entire screen, the result of the backlight control processing is the control signal CTL, and the brightness control value for each light emitting element LS is output as the control signal CTLB to the backlight device 10.

[0088] According to the present embodiment, it is possible to synthesize the backlight control based on the image analysis circuit 120 with the dimming control based on the external processing device 200. Specifically, the light emitting element that is determined to be turned on by the image analysis by the image analysis circuit 120 is reflected with the dimming control based on the external processing device 200. In addition, the light emitting element that is determined to be turned off by the image analysis by the image analysis circuit 120 is controlled to be turned off regardless of the dimming control of the external processing device 200. The control input of the backlight device 10 is usually one system, but according to the present embodiment, it is possible to input the dimming control based on the processing device 200 and the backlight control based on the image analysis circuit 120 in combination for the control input of the one system.

[0089] The circuit device of the above-described embodiment is used for a head-up display device. The head-up display device includes a display panel and a backlight device having a plurality of light emitting elements. The circuit device includes a distortion correction circuit and an image analysis circuit. The distortion correction circuit performs distortion correction on input image data, and outputs output image data after the distortion correction. The image analysis circuit analyzes analysis target image data that is the input image data or the output image data, and performs a backlight control processing of causing a light emitting element corresponding to a display region that becomes a transparent color when projected by the head-up display device among a plurality of display regions in the display panel corresponding to the plurality of light emitting elements to be in an off state, based on the result of the analysis.

[0090] According to the present embodiment, the display region that becomes transparent when projected by the head-up display device is determined by image analysis. Furthermore, the light emitting element corresponding to the display region that becomes transparent when projected by the head-up display device among the plurality of light emitting elements provided to the backlight device is turned off, and thus the display region is displayed as the original transparent region without whitening in the HUD display. Thus, even in a dark background situation such as at night or in a tunnel, the region without a display object in the HUD display becomes the original transparent region, and the visibility of the background is not reduced.

[0091] In addition, in the present embodiment, the image analysis circuit can also perform a backlight control process of analyzing whether the analysis target image data in each of the plurality of display regions is transparent color data, and turning off the light emitting element corresponding to the display region analyzed as the analysis target image data being transparent color data.

[0092] According to the present embodiment, the image analysis circuit performs image analysis of analyzing whether the analysis target image data in each display region is transparent color data, and thus can determine the display region that becomes transparent when projected by the head-up display device among the plurality of display regions.

[0093] Further, in the present embodiment, the distortion correction circuit can also include a coordinate counter that counts the pixel coordinates of the analysis target image data. The image analysis circuit can determine the display region to which each pixel of the analysis target image data belongs among the plurality of display regions based on the pixel coordinates output by the coordinate counter, and determine the display region that becomes transparent based on the determination result.

[0094] According to the present embodiment, since the pixel coordinates output by the coordinate counter indicate the pixel coordinates of each pixel in the analysis target image data, the image analysis circuit can determine the display region to which each pixel of the analysis target image data belongs among the plurality of display regions based on the pixel coordinates.

[0095] Further, in the present embodiment, the image analysis circuit can determine whether the pixel data belonging to each of the plurality of display regions is transparent color data based on the pixel coordinates output by the coordinate counter and the pixel data of the analysis target image data at the pixel coordinates, and thus determine whether each display region is a display region that becomes transparent.

[0096] According to the present embodiment, the image analysis circuit can determine whether the display region to which the pixel coordinate belongs and the pixel data of the pixel coordinate are data of a transparent color. Thereby, the image analysis circuit can determine whether each display region is a display region that becomes a transparent color when projected by the head-up display device. Further, according to the present embodiment, the analysis target image data is input image data input to the distortion correction circuit or output image data output from the distortion correction circuit, and the pixel coordinate output from the coordinate counter included in the distortion correction circuit is used for image analysis. Thereby, the distortion correction circuit performs distortion correction, and backlight control by image analysis by the image analysis circuit can be performed in parallel therewith, so that adjustment of a time lag of the HUD display and the backlight control can not be needed or can be simplified.

[0097] Further, in the present embodiment, the analysis target image data can also be output image data. The distortion correction circuit can also transform the pixel coordinate output from the coordinate counter into a reference coordinate on the input image data, output the pixel data of the output image data at the reference coordinate based on the pixel data of the input image data at the reference coordinate, and thereby perform distortion correction. The image analysis circuit can also determine which display region of the plurality of display regions the pixel coordinate output from the coordinate counter belongs to, and determine whether the display region determined to belong to the pixel coordinate is a display region that becomes a transparent color based on the pixel data of the output image data at the pixel coordinate output from the distortion correction circuit.

[0098] According to the present embodiment, backlight control based on image analysis is performed based on the pixel coordinate output from the coordinate counter used for distortion correction and the pixel data of the output image data corresponding to the pixel coordinate and output from the distortion correction circuit. Thereby, since distortion correction and backlight control based on image analysis are processed in parallel, adjustment of a time lag of the HUD display and the backlight control can not be needed or can be simplified.

[0099] Further, in the present embodiment, the analysis target image data can also be input image data. The image analysis circuit can also include a coordinate transformation circuit and a determination circuit. The coordinate transformation circuit can also transform the pixel coordinate output from the coordinate counter into a movement destination coordinate on the output image data. The determination circuit can also determine which display region of the plurality of display regions the movement destination coordinate belongs to, and determine whether the display region determined to belong to the movement destination coordinate is a display region that becomes a transparent color based on the pixel data of the input image data at the pixel coordinate.

[0100] According to the present embodiment, the pixel coordinates of the input image data input to the distortion correction circuit are counted, and the pixel coordinates are converted into movement destination coordinates on the output image data. Then, based on the movement destination coordinates and the pixel data of the pixel coordinates in the input image data, the backlight control based on the image analysis is performed. Thus, since the distortion correction and the backlight control based on the image analysis are processed in parallel, it is possible to eliminate or simplify the time lag adjustment of the HUD display and the backlight control.

[0101] Further, in the present embodiment, it is also possible to adopt a method in which the distortion correction circuit includes a correction coordinate counter that counts the coordinates on the output image data, and the distortion correction is performed based on a first coordinate conversion that converts the coordinates output from the correction coordinate counter into reference coordinates on the input image data. The coordinate conversion circuit can also calculate the movement destination coordinates by performing a second coordinate conversion that is an inverse conversion of the first coordinate conversion on the pixel coordinates output from the coordinate counter.

[0102] According to the present embodiment, in addition to the correction coordinate counter for reverse distortion, a coordinate counter that counts the pixel coordinates of the input image data, and a coordinate conversion circuit that converts the pixel coordinates into movement destination coordinates on the output image data are provided. Thus, it is possible to use the input image data as the analysis target image data, and determine whether the display region becomes transparent when projected by the head-up display device.

[0103] Further, in the present embodiment, the circuit device can also include a luminance control value calculation circuit and an interface circuit. The luminance control value calculation circuit can calculate the luminance control value of each of the plurality of light emitting elements by changing the backlight control signal received from the external processing device based on the result of the backlight control processing by the image analysis circuit. The interface circuit can output the luminance control value for each of the light emitting elements to the backlight device.

[0104] According to the present embodiment, it is possible to synthesize the dimming control based on the external processing device and the backlight control based on the image analysis circuit. Specifically, the light emitting element that the image analysis circuit determines to be turned on by the image analysis is reflected based on the dimming control by the external processing device. In addition, the light emitting element that the image analysis circuit determines to be turned off by the image analysis is controlled to be turned off regardless of the dimming control by the external processing device. The control input of the backlight device is usually one system, but according to the present embodiment, it is possible to input the dimming control based on the processing device and the backlight control based on the image analysis circuit in combination with respect to the control input of the one system.

[0105] In addition, the head-up display device of the present embodiment includes the circuit device of any one of the above, the display panel, and the backlight device.

[0106] Furthermore, although the present embodiment has been described in detail as described above, it will be readily apparent to those skilled in the art that various changes can be made thereto without departing from the new matters and effects of the present disclosure. Accordingly, such modified examples are all within the scope of the present disclosure. For example, in the specification or drawings, a term recited at least once together with a different term that is more general or synonymous can be replaced with the different term at any place in the specification or drawings. In addition, all combinations of the present embodiment and the modified examples are also within the scope of the present disclosure. Furthermore, the structure and operation of the circuit device, the display device, the backlight device, and the like are not limited to those described in the present embodiment, and various modifications can be made thereto.

Claims

1. A circuit arrangement, characterized by The circuit device is for a head-up display device including a display panel and a backlight device having a plurality of light emitting elements, and includes: a distortion correction circuit that performs distortion correction on input image data, and outputs output image data that is distortion-corrected; and an image analysis circuit that performs a backlight control process in which the output image data is analyzed, and based on a result of the analysis, causes light emitting elements corresponding to a display region that is a display region among a plurality of display regions of the display panel corresponding to the plurality of light emitting elements that becomes a transparent color when projected by the head-up display device to be in an extinguished state, the distortion correction circuit includes a coordinate counter that counts pixel coordinates of the output image data, the distortion correction circuit transforms the pixel coordinates output by the coordinate counter into reference coordinates on the input image data, and based on pixel data of the input image data at the reference coordinates, outputs pixel data of the output image data at the pixel coordinates, thereby performing the distortion correction, the image analysis circuit determines which display region among the plurality of display regions the pixel coordinates output by the coordinate counter belong to, and based on pixel data of the output image data at the pixel coordinates output by the coordinate counter, determines whether the display region determined to be the display region to which the pixel coordinates belong is the display region that becomes the transparent color.

2. The circuit device according to claim 1, wherein the image analysis circuit performs the backlight control process in which whether the output image data in each of the plurality of display regions is data that is the transparent color is analyzed, and causes light emitting elements corresponding to a display region in which the output image data is analyzed to be data that is the transparent color to be in the extinguished state.

3. The circuit device according to claim 1 or 2, wherein the circuit device includes: a luminance control value calculation circuit that, based on a result of the backlight control process from the image analysis circuit, changes a backlight control signal received from an external processing device, and thereby calculates a luminance control value for each of the plurality of light emitting elements; and an interface circuit that outputs the luminance control value for each of the light emitting elements to the backlight device. The circuit device is for a head-up display device including a display panel and a backlight device having a plurality of light emitting elements, and includes:

4. A circuit arrangement, characterized by a distortion correction circuit that performs distortion correction on input image data, and outputs output image data that is distortion-corrected; and an image analysis circuit that performs a backlight control process in which the output image data is analyzed, and based on a result of the analysis, causes light emitting elements corresponding to a display region that is a display region among a plurality of display regions of the display panel corresponding to the plurality of light emitting elements that becomes a transparent color when projected by the head-up display device to be in an extinguished state, the distortion correction circuit includes a coordinate counter that counts pixel coordinates of the output image data, the distortion correction circuit transforms the pixel coordinates output by the coordinate counter into reference coordinates on the input image data, and based on pixel data of the input image data at the reference coordinates, outputs pixel data of the output image data at the pixel coordinates, thereby performing the distortion correction, the image analysis circuit determines which display region among the plurality of display regions the pixel coordinates output by the coordinate counter belong to, and based on pixel data of the output image data at the pixel coordinates output by the coordinate counter, determines whether the display region determined to be the display region to which the pixel coordinates belong is the display region that becomes the transparent color. The distortion correction circuit includes a storage circuit that temporarily stores the input image data, and a coordinate counter that counts pixel coordinates of pixel data sequentially written into the storage circuit, The distortion correction circuit performs the distortion correction on the input image data stored in the storage circuit, The image analysis circuit includes: a coordinate conversion circuit that converts the pixel coordinates output from the coordinate counter into movement destination coordinates on the output image data; and a determination circuit that determines which of the plurality of display regions the movement destination coordinates belong to, and determines whether the display region to which the movement destination coordinates are judged to belong is a display region that becomes the transparent color, based on pixel data of the input image data at the pixel coordinates.

5. The circuit device according to claim 4, wherein the image analysis circuit performs the backlight control processing of analyzing whether the input image data in each of the plurality of display regions is data of the transparent color, and causing the light emitting element corresponding to the display region in which the input image data is analyzed to be data of the transparent color to be in the turned-off state.

6. The circuit device according to claim 4 or 5, wherein the distortion correction circuit includes a correction coordinate counter that counts coordinates on the output image data, and performs the distortion correction based on a first coordinate conversion that converts coordinates output from the correction coordinate counter into reference coordinates on the input image data, the coordinate conversion circuit performs a second coordinate conversion that is an inverse conversion of the first coordinate conversion on the pixel coordinates output from the coordinate counter, thereby obtaining the movement destination coordinates.

7. The circuit device according to claim 4 or 5, wherein the circuit device includes: a luminance control value calculation circuit that changes a backlight control signal received from an external processing device based on a result of the backlight control processing from the image analysis circuit, thereby calculating a luminance control value for each light emitting element of the plurality of light emitting elements; and an interface circuit that outputs the luminance control value for each light emitting element to the backlight device. The head-up display device includes:

8. A head-up display device, characterized by the circuit device according to any one of claims 1 to 7; the display panel; and the backlight device. ​

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