Semiconductor device and display system

Abstract

To provide a semiconductor device and a display system which can realize control of OSD display according to abnormalities, by a simpler configuration.SOLUTION: A semiconductor device 10 includes: an input interface 120 for receiving video data in which a picture of an existing character can be drawn; an OSD generation circuit 104 for generating OSD data including an OSD character corresponding to the existing character; an OSD superimposition circuit 106 for superimposing the OSD character on the video data on the basis of the OSD data; a determination unit 110 for determining the normality in the existing character on the basis of the OSD data; and a superimposition control unit 118 for controlling superimposition of the OSD character on the video data by the OSD superimposition circuit according to the result of determination that the determination unit has made regarding the normality. The OSD generation circuit outputs the OSD data to the OSD superimposition circuit and the determination unit in synchronization.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a semiconductor device and a display system.

Background Art

[0002] Conventionally, an OSD (On Screen Display) function that displays an icon or the like superimposed on an image input from the outside on a screen such as a display has been used. For example, Patent Document 1 discloses a technique for providing an OSD function to an in-vehicle display device. Patent Document 1 discloses reference graphic data that describes a predetermined shape that may be included in input image data and a timing controller that determines the presence or absence of an abnormality based on the input image data.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] [Summary] However, the present inventors have come to recognize the following problems. That is, when a circuit that detects an abnormality is controlled independently of a circuit that controls the OSD display as in the technique described in Patent Document 1, there is a problem that the circuit scale becomes large.

[0005] The present disclosure has been made in view of such circumstances, and one of its exemplary purposes is to provide a semiconductor device and a display system that can control OSD display according to an abnormality with a simpler configuration.

[0006] One aspect of the present disclosure is a semiconductor device. The semiconductor device includes an input interface that receives video data on which known characters can be drawn, an OSD generation circuit that generates OSD data including OSD characters corresponding to the known characters, an OSD overlay circuit that overlays the OSD characters on the video data based on the OSD data, a determiner that determines the normality of the known characters based on the OSD data, and an overlay controller that controls the overlay of the OSD characters on the video data by the OSD overlay circuit according to the normality determination result by the determiner. The OSD generation circuit synchronously outputs the OSD data to the OSD overlay circuit and the determiner.

[0007] Another aspect of the present disclosure is a display system. The display system includes the semiconductor device described above and a display device that displays an image based on the video data with the OSD characters overlaid.

[0008] In addition, any combination of the above components, as well as those obtained by converting the expressions of the present disclosure among methods, devices, systems, etc., are also effective as aspects of the present disclosure.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0010] [Detailed Description] (Overview) An overview of some exemplary embodiments of the present disclosure is described. This overview is for the purpose of providing a basic understanding of the embodiments as a prelude to the detailed description to follow, and simplifies and describes some concepts of one or more embodiments. It does not limit the scope of the invention or disclosure. This overview is not an all-inclusive overview of all possible embodiments, nor is it intended to identify important elements of all embodiments or to delineate the scope of some or all aspects. For convenience, "one embodiment" may be used to refer to one embodiment (example or variation) or a plurality of embodiments (examples or variations) disclosed herein.

[0011] A semiconductor device according to one embodiment includes an input interface that receives video data on which known characters can be drawn, an OSD generation circuit that generates OSD data including OSD characters corresponding to the known characters, an OSD superimposing circuit that superimposes the OSD characters on the video data based on the OSD data, a determiner that determines the normality of the known characters based on the OSD data, and a superimposing controller that controls the superimposition of the OSD characters on the video data by the OSD superimposing circuit according to the normality determination result by the determiner. The OSD generation circuit synchronously outputs the OSD data to the OSD superimposing circuit and the determiner.

[0012] According to this configuration, control of OSD display in response to an abnormality can be realized with a simpler configuration.

[0013] In one embodiment, the superimposing controller may determine whether to superimpose the OSD characters on the video data by the OSD superimposing circuit according to the determination result.

[0014] In one embodiment, when the determiner determines that there is an abnormality in the known characters to be drawn, the superimposing controller may cause the OSD superimposing circuit to superimpose the OSD characters corresponding to the known characters on the video data.

[0015] In one embodiment, when the determiner determines that the known character to be drawn is normal, the superimposer does not have to superimpose the OSD character corresponding to the known character on the video data in the OSD superimposing circuit.

[0016] In one embodiment, the determiner may be configured to further determine the visibility of the known character based on a plurality of pixels constituting the background area included in the target area where the known character is drawn. The superimposer may control the superimposition of the OSD character on the video data by the OSD superimposing circuit based on the determination result of the visibility and the determination result of the normality by the determiner.

[0017] In one embodiment, the semiconductor device may further include an image generation circuit that generates image data for fail-safe. The OSD superimposing circuit may superimpose the OSD character on the image data for fail-safe at the time of fail-safe. The determiner may determine the normality of the known character based on the OSD data at the time of fail-safe.

[0018] A display system according to another embodiment includes the semiconductor device and a display device that displays an image based on the video data on which the OSD character is superimposed.

[0019] According to this configuration, it is possible to realize the control of the OSD display according to an abnormality with a simpler configuration.

[0020] (Embodiment) Hereinafter, preferred embodiments will be described with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and repeated explanations are omitted as appropriate. Further, the embodiments are illustrative and not intended to limit the disclosure and the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the disclosure and the invention.

[0021] As used herein, the phrase "member A is in a state of being connected to member B" includes not only the case where member A and member B are physically and directly connected, but also the case where member A and member B are indirectly connected via other members that do not substantially affect their electrical connection state or impair the functions and effects achieved by their connection.

[0022] Similarly, the phrase "member C is in a state of being connected (or provided) between member A and member B" includes not only the case where member A and member C, or member B and member C are directly connected, but also the case where they are indirectly connected via other members that do not substantially affect their electrical connection state or impair the functions and effects achieved by their connection.

[0023] FIG. 1 is a block diagram showing the configuration of a display system 1 according to an embodiment of the present disclosure. In this embodiment, an example in which the display system 1 is mounted on an automobile will be described. The display system 1 includes a semiconductor device 10, a microcomputer 12 (microcontroller), an external memory 14, a graphic controller 16, and a display device 20. The graphic controller 16 is mounted on an image processing board B1. The semiconductor device 10, the microcomputer 12, and the external memory 14 are mounted on a cluster board B2.

[0024] The graphic controller 16 may be configured by a GPU (Graphics Processing Unit) or the like. The graphic controller 16 is connected to the semiconductor device 10 via a video transmission line L1. The graphic controller 16 generates video data D1. The video data D1 is transmitted to the semiconductor device 10.

[0025] The semiconductor device 10 may include a timing controller, a bridge circuit, a repeater circuit, a serializer / deserializer, a splitter, a replicator, a selector, a switch, a hub, etc. In this embodiment, the semiconductor device 10 is a timing controller.

[0026] During normal operation, the semiconductor device 10 receives video data D1 from the graphic controller 16 and superimposes OSD characters on the video data D1 according to the control by the microcomputer 12. The OSD characters to be superimposed may be characters indicating display lights, warning lights, and the like. The output image data Dout including the video data with the OSD characters superimposed thereon is transmitted to the display device 20. Note that the output image data Dout may not have the OSD characters superimposed thereon.

[0027] The display lights and warning lights displayed on the display device 20 are important information for the driver. For this reason, as in this embodiment, it is preferable that the OSD display is controlled by a controller (semiconductor device 10) independent of the graphic controller 16.

[0028] The microcomputer 12 integrally controls the display system 1. The microcomputer 12 and the semiconductor device 10 are connected via a control line L2 that is a different system from the video transmission line L1. An I2C interface or SPI (Serial Peripheral Interface) can be used for the control line L2.

[0029] The microcomputer 12 may transmit various signals to the semiconductor device 10 for display on the display device 20. For example, the microcomputer 12 may transmit a signal indicating the operating state of the microcomputer 12 and a signal for controlling the OSD function of the semiconductor device 10 to the semiconductor device 10.

[0030] The external memory 14 stores data related to characters for OSD. The external memory 14 is not particularly limited and may be a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), or the like. The data of the external memory 14 is transmitted to the semiconductor device 10 via the data transmission line L3.

[0031] The display device 20 includes a display panel 200, a gate driver 202, and a source driver 204. The display panel 200 may be composed of a liquid crystal panel, an organic EL (Electro-Luminescence) panel, or the like.

[0032] The display panel 200 displays an image based on video data D1 and image data for OSD. Specifically, the display panel 200 displays an image based on video data with OSD characters superimposed. Note that the display panel 200 may also display an image that does not include OSD characters.

[0033] The display panel 200 may be composed of, for example, a liquid crystal panel. The display panel 200 according to the present embodiment is composed of a meter cluster panel mounted on an automobile and can display various types of information necessary for driving the automobile. The display panel 200 may display, for example, display lights and warning lights, and may also display a speedometer and a travel distance.

[0034] The display panel 200 includes a pixel array. The pixel array has a plurality of pixel circuits arranged in a plurality of rows and columns, a plurality of gate lines GL respectively provided corresponding to the plurality of rows, and a plurality of source lines SL respectively provided corresponding to the plurality of columns.

[0035] The gate driver 202 sequentially selects the plurality of gate lines GL of the pixel array one by one at predetermined time intervals. The source driver 204 writes a voltage of a level corresponding to the data transmitted from the semiconductor device 10 to each pixel circuit corresponding to the gate line GL selected by the gate driver 202 via each source line SL. By sequentially writing the voltages, an image is displayed on the display panel 200.

[0036] FIG. 2 is a block diagram of the semiconductor device 10 according to the present embodiment. The semiconductor device 10 according to the present embodiment includes an OSD circuit block 100, an input interface 120, an image generation circuit 122, and a selector 124.

[0037] The input interface 120 receives video data D1 on which known characters can be drawn. The known characters may be characters having the same shape and color as, for example, indicator lights and warning lights. The received video data D1 is transmitted to the OSD circuit block 100 and the selector 124.

[0038] The image generation circuit 122 generates fail-safe image data Dfs. The image data Dfs is input to the selector 124. Here, fail-safe is a state in which the display of the display device 20 based on the video data D1 cannot be performed due to an abnormality in the graphic controller 16 or the like. In such a fail-safe state, an image corresponding to the image data Dfs is displayed on the display device 20. The fail-safe image data Dfs may be data for displaying, for example, a single-color (for example, black) image.

[0039] The selector 124 selects one of the input video data D1 and the image data Dfs, and generates input image data Din to the OSD circuit block 100. An image corresponding to the data selected by the selector 124 is displayed on the display device 20.

[0040] The OSD circuit block 100 performs determination of normality and visibility in the input image data Din, superimposes OSD characters on the input image data Din according to the determination result, and generates output image data Dout.

[0041] The OSD circuit block 100 includes an internal memory 102, an OSD generation circuit 104, an OSD superimposition circuit 106, a determiner 110, and a superimposition controller 118.

[0042] The internal memory 102 stores data Dcm related to OSD characters. The internal memory 102 is not particularly limited and may be, for example, SRAM (Static Random Access Memory) or the like. The data Dcm is referred to by the OSD generation circuit 104 as needed.

[0043] The OSD generation circuit 104 generates OSD image data Dci including OSD characters that can be superimposed on the image data Din based on the data Dcm. More specifically, it generates OSD data including OSD characters corresponding to known characters drawn based on the video data D1. The OSD characters may be characters having the same shape and color as the known characters.

[0044] The OSD generation circuit 104 transmits the OSD image data Dci to the OSD superimposition circuit 106 and the discriminator 110 synchronously, one pixel at a time, for each frame. Thereby, the OSD superimposition circuit 106 and the discriminator 110 can execute processing according to the OSD image data Dci simultaneously.

[0045] The OSD superimposition circuit 106 superimposes OSD characters on the input image data Din based on the OSD data according to the control signal Scon from the superimposition controller 118. Note that the input image data Din on which the OSD superimposition circuit 106 superimposes the OSD characters may be the video data D1 or the fail-safe image data Dfs. Therefore, the OSD superimposition circuit 106 can superimpose OSD characters on the fail-safe image data Dfs even during fail-safe.

[0046] The OSD characters included in the OSD image data Dci are superimposed on the input image data Din to generate output image data Dout. Note that the OSD superimposition circuit 106 does not necessarily have to superimpose OSD characters on the input image data Din.

[0047] The discriminator 110 performs a determination on the video data D1 and generates a signal Serr indicating the determination result. Specifically, the discriminator 110 determines the normality of known characters included in the video data D1 based on the OSD data Dci. The discriminator 110 can determine the normality of known characters based on the OSD data Dci during fail-safe. As described above, during fail-safe, the OSD characters are superimposed on the fail-safe image data Dfs. Therefore, according to the present embodiment, while displaying the OSD characters on the display device 20, it is possible to simultaneously perform determinations such as the normality regarding the video data D1.

[0048] Further, the discriminator 110 according to the present embodiment is configured to further determine the visibility of known characters based on a plurality of pixels constituting the background area included in the target area where the known characters are drawn. The discriminator 110 includes an image comparator 112, a visibility detector 114, and a final discriminator 116.

[0049] The image comparator 112 compares the video data D1 and the OSD image data Dci and generates a signal Sic indicating the comparison result. The process of the image comparator 112 is also referred to as IMC (Image Comparison). The image comparator 112 compares each pixel of the OSD characters included in the OSD image data Dci with each pixel constituting a known character that may be included in the video data D1. The image comparator 112 generates a signal Sic indicating abnormality or normality for each pixel. The signal Sic is transmitted to the final discriminator 116.

[0050] The visibility detector 114 detects the visibility of a plurality of pixels constituting a background region included in a target region where a known character is drawn in the video data D1. A signal Svd indicating the detection result is transmitted to the final decision maker 116. For example, the visibility detector 114 may detect the visibility of a known character based on the color and brightness of the background region included in the target region where the known character is drawn. Specifically, the visibility detector 114 may compare the reference color with the color of the target background region for each pixel and detect the visibility according to the color difference.

[0051] The final decision maker 116 generates an error signal VSB_ERR according to the processing results of the image comparator 112 and the visibility detector 114, and transmits the error signal VSB_ERR to the superimposition controller 118.

[0052] The superimposition controller 118 controls the superimposition of the OSD character on the input image data Din by the OSD superimposition circuit 106 according to the determination result of the normality of the known character by the decision maker 110. In this embodiment, the superimposition controller 118 transmits a control signal Scon to the OSD superimposition circuit 106 according to the error signal VSB_ERR to control the operation of the OSD superimposition circuit 106.

[0053] In this embodiment, the superimposition controller 118 determines whether to superimpose the OSD character on the input image data Din by the OSD superimposition circuit 106 according to the determination result by the decision maker 110. By superimposing the OSD character on the input image data Din as needed in this way, it becomes possible to more reliably display the character to be displayed on the display device 20.

[0054] For example, when the determiner 110 determines that there is an abnormality in a known character to be drawn, the overlay controller 118 may cause the OSD overlay circuit 106 to overlay an OSD character corresponding to the known character on the input image data Din. More specifically, when it is detected that there is an abnormality in a known character to be drawn for a continuous number of frames equal to or greater than a predetermined number of frames, the OSD overlay circuit 106 may overlay an OSD character corresponding to the known character on the input image data Din. Thereby, even if there is an abnormality in the known character, by displaying the OSD character, it is possible to more reliably provide necessary information to a driver or the like.

[0055] On the other hand, when the determiner 110 determines that a known character to be drawn is normal, the overlay controller 118 does not have to cause the OSD overlay circuit 106 to overlay an OSD character corresponding to the known character on the input image data Din. More specifically, when it is not detected that there is an abnormality in a known character to be drawn for a continuous number of frames equal to or greater than a predetermined number of frames, the OSD overlay circuit 106 does not have to overlay an OSD character corresponding to the known character on the input image data Din. Thereby, it is suppressed that the OSD character is unnecessarily overlaid on the input image data Din.

[0056] In addition, the overlay controller 118 can control the overlay of the OSD character on the input image data Din by the OSD overlay circuit 106 based on the determination result of the normality of the known character by the determiner 110 and the determination result of the visibility of the character. For example, when frames in which there is an abnormality in a known character continue for a predetermined number or more and frames in which the visibility of the known character is poor continue for a predetermined number or more, the overlay controller 118 may cause the OSD overlay circuit 106 to overlay an OSD character corresponding to the known character on the input image data Din. By using the visibility of the character in addition to the normality of the known character, it becomes possible to more appropriately control the overlay of the OSD character.

[0057] FIG. 3 is a block diagram of the image comparator 112, visibility detector 114, and final decision maker 116 according to this embodiment.

[0058] The image comparator 112 includes a drawing pixel extraction unit 140 and a pixel determination unit 142.

[0059] The drawing pixel extraction unit 140 extracts pixels included in a drawing area where a known character is to be drawn from the target area of the video data D1. The drawing pixel extraction unit 140 extracts the pixels of the drawing area based on the α value (a value indicating the transparency of each pixel) included in the OSD data Dci. Specifically, since the area where the OSD character is drawn in the OSD data Dci is opaque, the drawing pixel extraction unit 140 may extract the pixels at positions having an α value equal to or greater than a predetermined value. Let the pixel values of the extracted pixels be Rj, Gj, and Bj.

[0060] The pixel determination unit 142 determines the presence or absence of an error for each pixel based on the error between the pixel values Rj, Gj, Bj of each of the plurality of pixels included in the drawing area and an expected value, and transmits a signal Sic indicating the determination result to the final decision maker 116. Let the expected values of each pixel be OSD_R, OSD_G, and OSD_B.

[0061] The pixel determination unit 142 may support two determination modes. In the first determination mode, |Rj - OSD_R| > 16×L |Gj - OSD_G| > 16×L |Bj - OSD_B| > 16×L When any of the above is satisfied, that pixel is determined as an error. L is a parameter for setting a threshold value and can be set by a register in the range of 0 to 15. This determination mode detects that the character is not lit correctly as an error.

[0062] In the second determination mode, |Rj - OSD_R| ≤ 16×L |Gj - OSD_G| ≤ 16×L |Bj - OSD_B| ≤ 16 × L When all of these are satisfied, the pixel is determined to be an error. This determination mode detects as an error that the character is not properly turned off.

[0063] The visibility detector 114 includes a background pixel extraction unit 160, a color difference error detection unit 162, a brightness difference error detection unit 164, and an OR gate 166.

[0064] The background pixel extraction unit 160 extracts pixels included in the background area from the target area of the video data D1. The background pixel extraction unit 160 may extract pixels included in the background area based on the α value. For example, the background pixel extraction unit 160 may extract pixels at positions having an α value less than a predetermined value. Let the pixel values of the extracted pixels be Ri, Gi, Bi.

[0065] The pixel values (Ri, Gi, Bi) are input to the color difference error detection unit 162 and the brightness difference error detection unit 164 together with the reference color (Rr, Gr, Br). The reference color (Rr, Gr, Br) is a color uniquely determined for each OSD character. When the OSD character is composed of one color, the reference color (Rr, Gr, Br) may match the color of the OSD character. When the OSD character is composed of a plurality of colors, the reference color (Rr, Gr, Br) may be determined based on the plurality of colors.

[0066] In the present embodiment, the visibility detector 108 checks for errors based on the color difference between the background color (Ri, Gi, Bi) and the reference color (Rr, Gr, Br), and the brightness difference.

[0067] The color difference error detection unit 162 calculates the color difference CDi based on Equation (1). CDi = |Ri - Rr| + |Gi - Gr| + |Bi - Br| …(1) The color difference error detection unit 162 compares the color difference CDi with the color difference threshold value T, determines it as an error when CDi < T, and outputs high.

[0068] The brightness difference error detection unit 164 calculates the brightness difference BDi based on Equation (2). BDi = |Ri - Rr| × x + |Gi - Gr| × y + |Bi - Br| × z …(2) Here, x, y, and z are parameters that satisfy x + y + z = 1. The brightness difference error detection unit 164 compares the brightness difference BDi with the brightness difference threshold U, determines an error when BDi < U, and outputs HIGH.

[0069] The color difference threshold T and the brightness difference threshold U are T = 64 × N U = 16 × M may be defined as follows. N and M are set values set in the register and can take values from 0 to 15, for example.

[0070] The OR gate 166 asserts the signal Svd when the color difference is less than the color difference threshold T or when the brightness difference is less than the brightness difference threshold U.

[0071] The final decision maker 116 makes a decision regarding the video data D1 based on the comparison result of the image comparator 112 and the detection result of the visibility detector 114. The final decision maker 116 includes a first selector 180, a second selector 182, a region determination unit 184, and a frame determination unit 186.

[0072] The selector SEL1 alternately selects the output of the image comparator 112 and the output of the visibility detector 114 for each frame. For example, in odd frames, the image comparator 112 becomes effective and performs IMC, and in even frames, the visibility detector 114 becomes effective and may perform a visibility check. The selector SEL2 may switch the threshold P of the region determination unit 184 between the value P_VD for visibility check and the value P_IMC for IMC for each frame.

[0073] When performing IMC, the area determination unit 184 counts the number of pixels with errors. If the counted number of pixels exceeds the pixel count threshold p1, it determines that there is an abnormality in the known characters in that frame and asserts the RNG_ERR signal. For example, the pixel count threshold p1 can be obtained by multiplying the total number of pixels of the character size included in the target area by the coefficient P1. The coefficient P1 represents the ratio of allowing errors.

[0074] When performing the visibility check, the area determination unit 184 counts the number of pixels with errors. If the counted number of pixels exceeds the pixel count threshold p2, it determines that the visibility of the known characters in that frame is poor and asserts the RNG_ERR signal. The pixel count threshold p2 can be obtained by multiplying the total number of pixels of the background area included in the target area by the coefficient P2. The coefficient P2 represents the ratio of allowing errors.

[0075] The frame determination unit 186 outputs the final error signal VSB_ERR according to the RGN_ERR signal. For example, in the process of IMC, when there are errors in the known characters continuously for the reference number of times, the frame determination unit 186 may determine that there is an abnormality in that character. On the other hand, when the number of consecutive errors does not exceed the reference number of times, it may be determined that the known characters are normal. Note that this reference number of times may be adjusted according to the result of the visibility check. For example, when there is an error in visibility, the reference number of times may be made smaller than the reference value.

[0076] FIG. 4 is a diagram for explaining an example of the operations of the image comparator 112 and the visibility detector 114. FIG. 4 shows the frame 300 included in the video data D1 and the OSD character data 320 used by the image comparator 112 for IMC.

[0077] Frame 300 has a known character 304 displayed on a background image 308 such as a car navigation system. The rectangular area where the known character 304 is drawn is the target area 302. Image comparison and visibility detection are performed on this target area 302.

[0078] The image comparator 112 compares the OSD character 322 included in the OSD character data 320 with the known character 304 pixel by pixel and outputs the comparison result. Note that the image comparator 112 does not need to use the background area 306 in the target area 302 and the background area 324 in the OSD character data 320 for the comparison.

[0079] The visibility detector 114 compares the background area 306 in the target area 302 with a reference color pixel by pixel. For example, when the known character 304 is entirely blue, the difference between the color of the background area 306 and blue is calculated pixel by pixel, and the result is output.

[0080] Based on the results processed pixel by pixel by the image comparator 112 and the visibility detector 114 in this way, the final decision maker 116 determines the normality, abnormality, and visibility of the known character 304.

[0081] FIG. 5 is a diagram for explaining an example of the overlay of the OSD character 322 when it is determined that there is an abnormality in the known character 312. On the left side of FIG. 5, a frame 310 with the known character 312 determined to be abnormal is shown, and on the right side of FIG. 5, image data 350 with the OSD character 322 overlaid according to the determination result is shown.

[0082] As shown in FIG. 5, since there is a defect in the known character 312 included in the frame 310, it is determined that there is an abnormality in the character 312. In this case, the OSD character 322 corresponding to the known character 312 is superimposed on the frame 310. This OSD character 322 has the same shape and color as when the known character 312 is displayed without defects. Thereby, even when there is an abnormality in the known character 312, by displaying the OSD character 322, it is possible to appropriately provide necessary information to a driver or the like.

[0083] As described above, an example of the configuration and operation of the display system 1 according to the present embodiment has been described. According to the semiconductor device 10 according to the present embodiment, the OSD generation circuit 104 synchronously outputs the OSD data Dci to the OSD superimposition circuit 106 and the determiner 110. In response to this, the OSD superimposition circuit 106 superimposes the OSD character on the input image data Din based on the OSD data Dci, and the determiner 110 determines the normality of the known character based on the OSD data Dci. The superimposition controller 118 controls the superimposition of the OSD character on the input image data Din by the OSD superimposition circuit 106 according to the normality determination result by the determiner 110. Thereby, even without using an external controller of the semiconductor device 10, the superimposition of the OSD character by the superimposition controller 118 can be controlled. As a result, with a simpler configuration, control of OSD display according to an abnormality can be realized.

[0084] (Supplementary) Regarding the embodiments according to the present disclosure, specific terms have been used for the description, but this description is merely an exemplification for facilitating understanding and does not limit the present disclosure or the scope of the claims. The scope of the present invention is defined by the scope of the claims. Also, not only the embodiments but also the embodiments, examples, and modifications not described here are included in the scope of the present invention.

[0085] In the above-described embodiment, an example of controlling an image displayed on a liquid crystal cluster panel has been mainly described. However, the present disclosure is not limited thereto, and the technology of the present disclosure can also be applied to a HUD (Head Up Display), an electronic mirror, and the like.

[0086] In the above-described embodiment, an example of alternately performing IMC and visibility detection has been described. However, the present disclosure is not limited thereto, and only the IMC process may be performed. In this case, the semiconductor device 10 may not have the visibility detector 114.

[0087] (Appendix) The technology disclosed in this specification can be understood as follows in one aspect.

[0088] (Item 1) An input interface that receives video data on which known characters can be drawn, An OSD generation circuit that generates OSD data including OSD characters corresponding to the known characters, An OSD overlay circuit that overlays the OSD characters on the video data based on the OSD data, A determiner that determines the normality of the known characters based on the OSD data, An overlay controller that controls the overlay of the OSD characters on the video data by the OSD overlay circuit according to the determination result of the normality by the determiner, The OSD generation circuit synchronously outputs the OSD data to the OSD overlay circuit and the determiner. A semiconductor device.

[0089] (Item 2) The overlay controller determines whether to overlay the OSD characters on the video data by the OSD overlay circuit according to the determination result. The semiconductor device according to Item 1.

[0090] (Item 3) When the determination device determines that there is an abnormality in the known character to be drawn, the superimposition controller causes the OSD superimposition circuit to superimpose the OSD character corresponding to the known character on the video data. The semiconductor device according to item 2.

[0091] (Item 4) When the determination device determines that the known character to be drawn is normal, the superimposition controller does not cause the OSD superimposition circuit to superimpose the OSD character corresponding to the known character on the video data. The semiconductor device according to item 2.

[0092] (Item 5) The determination device is configured to further determine the visibility of the known character based on a plurality of pixels constituting a background area included in a target area where the known character is drawn. The superimposition controller controls the superimposition of the OSD character on the video data by the OSD superimposition circuit based on the determination result of the visibility and the determination result of the normality by the determination device. The semiconductor device according to any one of items 1 to 4.

[0093] (Item 6) Further comprising an image generation circuit that generates image data for fail-safe. At the time of fail-safe, the OSD superimposition circuit superimposes the OSD character on the image data for fail-safe. At the time of fail-safe, the determination device determines the normality of the known character based on the OSD data. The semiconductor device according to any one of items 1 to 5.

[0094] (Item 7) A semiconductor device according to any one of items 1 to 6, and a display device that displays an image based on the video data on which the OSD character is superimposed. Display system

Description of symbols

[0095] 1 Display system, 10 Semiconductor device, 12 Microcomputer, 14 External memory, 16 Graphic controller, 20 Display device, 100 OSD circuit block, 102 Internal memory, 104 OSD generation circuit, 106 OSD superposition circuit, 110 Determinator, 112 Image comparator, 114 Visibility detector, 116 Final determinator, 118 Superposition controller, 140 Drawing pixel extraction unit, 142 Pixel determination unit, 160 Background pixel extraction unit, 162 Color difference error detection unit, 164 Luminance difference error detection unit, 166 OR gate, 180 First selector, 182 Second selector, 184 Region determination unit, 186 Final determination unit.

Claims

1. An input interface for receiving video data on which known characters can be drawn, an OSD generation circuit for generating OSD data including OSD characters corresponding to the known characters, an OSD superimposing circuit for superimposing the OSD characters on the video data based on the OSD data, a determiner for determining the normality of the known characters based on the OSD data, a superimposition controller for controlling the superimposition of the OSD characters on the video data by the OSD superimposing circuit according to the determination result of the normality by the determiner, and the OSD generation circuit synchronously outputs the OSD data to the OSD superimposing circuit and the determiner, a semiconductor device.

2. The superimposition controller determines whether to superimpose the OSD characters on the video data in the OSD superimposing circuit according to the determination result. The semiconductor device according to Claim 1.

3. When the determiner determines that there is an abnormality in the known characters to be drawn, the superimposition controller causes the OSD superimposing circuit to superimpose the OSD characters corresponding to the known characters on the video data. The semiconductor device according to Claim 2.

4. When the determiner determines that the known characters to be drawn are normal, the superimposition controller does not cause the OSD superimposing circuit to superimpose the OSD characters corresponding to the known characters on the video data. The semiconductor device according to Claim 2.

5. The determiner is configured to further determine the visibility of the known characters based on a plurality of pixels constituting a background area included in a target area where the known characters are drawn, and the superimposition controller controls the superimposition of the OSD characters on the video data by the OSD superimposing circuit based on the determination result of the visibility and the determination result of the normality by the determiner. The semiconductor device according to Claim 1.

6. Further comprising an image generation circuit for generating image data for fail-safe, the OSD superimposing circuit superimposes the OSD characters on the image data for fail-safe during fail-safe, and the determiner determines the normality of the known characters based on the OSD data during fail-safe. The semiconductor device according to claim 1.

7. A semiconductor device according to any one of claims 1 to 6, and a display device configured to display an image based on video data on which the OSD character is superimposed. A display system.

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