JP2013213898A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent overtaking of data at the time of display in a display device that displays video data by retrieving the video data from a storage unit at a pixel rate larger than the pixel rate for inputting the video data in the storage unit.SOLUTION: A storage unit 10 is preliminarily configured so as to divide a storage area into multiple buffers and to read and write video data (superimposed data illustrated by an example) by switching the buffers between those for retrieval and those for writing. A display device 1 comprises: a mask unit (a superimposed data mask unit 17 illustrated by an example) for masking a video part to be updated among the video data retrieved from a buffer 10b for reading; a write-back unit (a superimposed data write-back unit 14 illustrated by an example) for writing the video data after mask processing by the mask unit back to a buffer 10a for writing; an update data writing unit 13 for writing update data meaning the video data of the video part to be updated, into a masked portion in the buffer 10a by the mask unit.

Description

  The present invention relates to a display device, and more particularly to a display device capable of high-resolution display.

  At present, as a display device such as a television device or a monitor device, a device including a so-called Full HD (High Definition) display panel having a resolution of 2K1K (1920 × 1080 pixels) is mainly used. On the other hand, the demand for higher-definition display panels is also increasing, 4K2K size video, super high-definition video (8K4K size video) having 16 times the number of pixels (7680 × 4320 pixels) of Full HD, and 4 more Development of a display panel for displaying a 16K8K size image having twice the number of pixels and a display device including such a display panel have also been actively developed. Here, 4K2K means QFHD (Quad Full High Definition) having four times as many pixels as Full HD (3840 × 2160 pixels), 4K (4096 × 2160 pixels) defined by the standard of digital cinema, etc. Point to.

  On the other hand, video signals output from external video playback devices such as tuners, recorders, and players, and video signals decoded by receiving broadcast signals inside the display device are mainly 2K1K video. In addition, manufacturing a dedicated LSI (Large Scale Integrated Circuit) for a 4K2K size or the like as a receiving device for receiving an external video signal or a video signal from a broadcast wave requires a great investment. And Under such circumstances, an LSI that processes 2K1K size video data must be used as the receiving device.

  Therefore, when the video signal received by the receiving device is displayed on the full screen on the display panel having a resolution exceeding 2K1K as described above, the video data indicated by the video signal received by the receiving device is increased in resolution by scaling, It will be displayed on the display panel.

  On the display panel, graphic data such as OSD (On Screen Display) image data, photo data, and PC output image data may be displayed superimposed on video data. Since the graphic data itself is not suitable for scaling because there are many non-continuous data, when displaying on a high-resolution display panel such as 4K2K size, the resolution is first increased and then the scaled video data is displayed. Superimposed and displayed dot-by-dot. Such creation of high-resolution graphic data can be adequately handled in recent years when CPU (Central Processing Unit) speeds up.

  As a technique for synthesizing video using a display panel having a high resolution and a receiving device having a panel resolution lower than that, Patent Document 1 is disclosed for a transmission method in time division, and Patent Document 2 is used for reducing a transmission amount. Is disclosed.

  A broadcast receiver described in Patent Literature 1 receives a video signal indicating a moving image, generates a still image, and outputs the received image, and outputs a moving image or a still image output from the receiving device. And a display device that displays at a resolution exceeding that. Here, the receiving device outputs a moving image obtained by converting a video signal received from the outside to the first resolution, and a still image having a second resolution higher than the first resolution in response to an instruction from the outside. Generating a divided still image obtained by dividing the second resolution still image into the first resolution, and generating the divided still image and the first resolution moving image for each frame (that is, when Multiprocessing means for outputting (by division). In addition, the display device restores the divided still image to the still image of the second resolution, the display unit that displays the moving image and the still image of the second resolution, the scaling processing unit that expands the moving image of the first resolution, and And a blend processing means for displaying the expanded first resolution moving image and the restored second resolution still image on the display means. The moving image and the still image can be distinguished by transmitting an identification signal from the receiving device to the display device and determining the identification signal on the display device side.

  Patent Document 2 discloses an image display system including a personal computer (PC) that transmits image data based on a predetermined drawing command, and a reception-side monitor that displays image data received from the PC on a panel. A technique for reducing the transmission amount of image data is disclosed. Here, the PC is configured to draw data corresponding to the panel resolution on the internal frame memory, and transmits an area in which a change has occurred on the screen (change area) due to the drawing command. An area is determined, and image data in the transmission area is transmitted to the receiving monitor with control information indicating the transmission area added to the header. Based on the received control information, the reception-side monitor expands the received image data in the transmission area to an internal frame memory, updates the image data, and displays it on the panel. That is, this system is configured to transmit the data of the change area detected by the PC to the receiving monitor and copy it to the frame memory of the receiving monitor.

  Regarding data reading / writing in the memory, Patent Document 3 describes a technique for preventing overtaking of data at the time of display by dividing a memory bank into two and alternately performing writing and reading.

JP 2010-130544 A JP 2002-278526 A JP 2002-262175 A

  By the way, the graphic data to be superimposed on the video data of the video (main video) received and displayed by the receiving device often has a small display area, for example, when displayed in a sub-window at the time of two screens. Even in the case of an image, changes between frames rarely extend over the entire screen.

  However, in the technique described in Patent Document 1, it is necessary to update the data in the entire display area even if there is a small change, and input of 4 times the 2K1K size (resolution ratio) is required for updating the 4K2K size data. Since time (transmission time) is required, the frame rate becomes ¼, such as 15 fps if the original is 60 fps. Here, 1/4 means 1 / (resolution ratio), in other words, 1 / (number of time divisions).

  On the other hand, with the technique described in Patent Document 2, it is possible to reduce the input data from the PC to the display panel, but the input pixel rate and the output pixel rate are different (the output pixel rate is higher than the input pixel rate). In addition, since there is only one display buffer, a part of the update data is mixedly displayed as data of frames with different time axes, resulting in a video with a reduced quality. In the case of a still image such as a PC output that is assumed in the technology described in Patent Document 2, even if there is one frame of video in the middle of writing, there is little deterioration in visual quality. The data being written can be seen every frame. The reason why the videos of different times are mixed is that when the graphic data to be superimposed on the main video is rewritten, the data at the time of display is overtaken.

  The overtaking of data at the time of display described above will be described in detail with reference to FIGS. FIG. 1 shows a display device in which superimposition data is read from the memory at a pixel rate higher than the pixel rate at which the superimposition data is input to the memory, and is superimposed on the main video data for display. It is a conceptual diagram for demonstrating the ideal process performed without. FIG. 2 is a conceptual diagram for explaining a problem that actually occurs when superimposition data is updated as shown in FIG. 1 in a conventional display device. Here, as an example, the display output pixel rate (output pixel rate) is four times the input pixel rate (input pixel rate) as in the case of displaying a 2K1K size video on a 4K2K size display panel. Give an explanation.

  As shown in FIG. 1, 4K2K superimposition data (graphic data) MF (n) on the memory includes 2K1K update data updated for the frame F (n), and 2K1K update data is included therein. It is assumed that data GF (n + 1) is input in order to create superimposed data of frame F (n + 1). Here, n represents a time axis that is currently displayed, and represents a frame number to be displayed on the display panel. The update data GF (n + 1) is data of an update part of graphic data for the frame F (n + 1). For the main video, 4K2K main video data VSF (n) is generated by scaling the 2K1K main video data VF (n).

  When such main video and graphic data is input, ideally, the superimposed data on the memory for display preparation is MF (n + 1) in FIG. 1, and the display data itself is in FIG. The update data GF (n + 1) is not reflected as in DF (n). However, as will be described with reference to FIG. 2, in reality, such a display cannot be performed during writing, and the update data GF (n + 1) is partially reflected, resulting in a state in which different temporal images are mixed. End up.

  Since two lines of scaled video are created for one input main video data line, the necessary overlapping data in the memory is two lines for one input main video data line. Assuming that the update data is an area from the 11th line of the superimposed data, the state when the superimposed data and the scaled main video data are completed up to 10 lines is as shown in FIG. The data advances by 5 lines, and the update data GF (n + 1) [11-15] is written in the superimposed data MF (n + 1) on the memory for 5 lines of 11 to 15 lines. The main video data VF (n) [1-5] is scaled to VSF (n) [1-10] for 1 to 10 lines, and the display data DF (n) is also 1 to 10 lines. .

  When the display output of 20 lines further advances from such a state, that is, when the display data is completed up to 30 lines, as shown in FIG. 2B, the superimposed data MF (n + 1) on the memory is equivalent to 15 lines. Only is input, and this is superimposed on the scaled main video input data VSF (n) [1-30] to become display data DF (n). However, as shown in FIG. 2B, the superimposition data read as the display data DF (n) is displayed in that state, overtaking the superimposition data to be written, for example, on the eighth line of the superimposition data. Here, the superimposition data in the display data DF (n) is on the time axis, for example, up to 10 lines belong to n on the time axis, 11 to 18 lines belong to n + 1, and 19 to 60 lines belong to n. It will be mixed.

  When the superimposition data is not still image data (graphic data) but moving image data, the time axis is always mixed and the image is not established. When the superimposition data has been written to the last line (60 lines in this example), the superimposition data on the memory becomes MF (n + 1) in FIG. Display with is possible.

  The technique described in Patent Document 3 divides memory banks into two and performs writing and reading alternately. However, special consideration is given to the synthesis of still images and moving images transmitted at different frame rates. However, even if this technique is applied to such synthesis, overtaking of data at the time of display cannot be prevented when displaying at a frame rate higher than the input frame rate.

  This will be specifically described with reference to FIGS. FIG. 3 is a block diagram showing a configuration example when a write buffer and a read buffer are provided in a display memory in a conventional display device, and FIG. 4 is a conceptual diagram for explaining processing in the display device of FIG. It is. 3 includes a storage unit 110, a bus arbitration unit 111, an update data input unit 112, an update data write unit 113, a superimposition data read unit 115, an update data coordinate input unit 116, a blend unit 118, and a display data output. Unit 119, main video input unit 120, and scaling unit 121.

  The update data input unit 112 inputs the update data of the superimposition data and passes it to the update data writing unit 113, and the update data coordinate input unit 116 inputs the coordinate information of the update portion of the superimposition data and inputs the update data writing unit 113. To pass. The storage unit 110 includes a write buffer 110a and a read buffer 110b for managing the superimposed data, and video data can be read and written while switching the buffer between reading and writing.

  The update data writing unit 113 transmits a request to write update data to the write buffer 110a based on the coordinate information to the bus arbitration unit 111, and writes the update data to the write buffer 110a when there is a use authority. The superimposition data reading unit 115 transmits a request to read the superimposition data from the read buffer 110b to the bus arbitration unit 111. When there is a use right, the superimposition data reading unit 115 reads the superimposition data from the read buffer 110b and passes it to the blend unit 118. . The bus arbitration unit 111 arbitrates use authority for the storage unit 110 in response to the received write request and read request.

  The main video input unit 120 inputs the main video data VF (n) and passes it to the scaling unit 121. The scaling unit 121 is a scaler that can scale up the main video data to a predetermined resolution equal to or lower than the output resolution, and passes the scaled video data to the blend unit 118. The blending unit 118 blends (synthesizes) the superimposition data read by the superimposition data reading unit 115 and the main video data scaled by the scaling unit 121 and passes them to the display data output unit 119. The display data output unit 119 outputs and displays the combined video data output from the blending unit 118 on the display panel with a higher resolution video than the input main video.

  Referring to FIG. 4, the input data is 2K1K update data GF (n + 1) and 2K1K main video data VF (n), and the superimposed data on the read buffer 110b before input is MF (n) in FIG. The case will be described. In this case, the display data DF (n) on the time axis n is the 4K2K superimposition data (data in the read buffer 110b updated with the update data GF (n) and the main video data VSF (n) scaled to 4K2K. ) Is superimposed. On the other hand, the superimposition data MF (n) on the write buffer 110a includes, as its final state, update data 141 on the time axis n + 1 and unnecessary data (so-called dust data) 140 corresponding to an unwritten area. The display data DF (n) becomes the display data DF (n + 1) due to the superimposition of the superimposition data MF (n), but the entire area corresponding to the frame on the write buffer 110a including the unnecessary data 140 is included. Thus, such display data DF (n + 1) cannot be displayed unless writing is performed. That is, in the configuration example of FIG. 3, the update data for the frame F (n + 1) does not extend over the entire frame, but it is necessary to perform writing for the entire frame, resulting in display at a low frame rate. End up.

  As described above, when the output pixel rate is higher than the input pixel rate and there is only one display buffer, the data of frames with different time axes are mixed and displayed as a part of the update data, resulting in poor quality. In order to prevent this, even if a plurality of display buffers are provided, it is necessary to write data for the entire display area, including unnecessary data 140, as in the technique described in Patent Document 1. .

  The present invention has been made in view of the above situation, and an object of the present invention is to provide a display device that reads and displays video data from the storage unit at a pixel rate higher than the pixel rate at which the video data is input to the storage unit. It is to prevent overtaking of data at the time of display and to prevent the display of images in different time axes in a mixed state.

  In order to solve the above-mentioned problem, a first technical means of the present invention includes a storage unit for storing video data, and the video data from the storage unit at a pixel rate larger than a pixel rate for inputting the video data to the storage unit. The storage unit divides the storage area into a plurality of buffers, and is configured to be able to read and write video data while switching the buffer between reading and writing, The display device writes a mask portion for masking a video portion to be updated out of the video data read from the read buffer, and the video data subjected to the mask processing in the mask portion to the write buffer. The video of the video part to be updated in the part that is masked by the mask part in the write-back part to be returned and the write buffer Is obtained by comprising: the update data writing unit for writing the updated data is over data, the.

  According to a second technical means of the present invention, in the first technical means, a superimposing unit that superimposes the video data on other video data is further provided.

  According to a third technical means of the present invention, in the second technical means, the input pixel rate of the other video data is the same as the input pixel rate of the update data.

  According to the present invention, in a display device that reads and displays video data from the storage unit at a pixel rate higher than the pixel rate at which the video data is input to the storage unit, it prevents overtaking of data at the time of display, and images on different time axes Can be prevented from being displayed in a mixed state.

Ideal for a display device that reads superimposition data from the memory at a pixel rate greater than the pixel rate at which the superimposition data is input to the memory and superimposes it on the main video data, and updates the superimposition data on the memory without degrading the quality. It is a conceptual diagram for demonstrating an easy process. It is a conceptual diagram for demonstrating the problem which actually arises when superimposition data like FIG. 1 is updated in the conventional display apparatus. It is a block diagram which shows the structural example at the time of providing the writing buffer and the reading buffer in the memory for display in the conventional display apparatus. It is a conceptual diagram for demonstrating the process in the display apparatus of FIG. FIG. 4 is a block diagram illustrating a configuration example for explaining one of the features of the display device according to the present invention, and is a block diagram illustrating a configuration example in which superimposition data is written back in the configuration example of FIG. 3. It is a conceptual diagram for demonstrating the process in the display apparatus of FIG. It is a block diagram which shows one structural example of the display apparatus which concerns on this invention. It is a figure which shows an example of the data storage state of the memory | storage part in the display apparatus of FIG. It is a conceptual diagram for demonstrating the process in the display apparatus of FIG. It is a block diagram which shows the other structural example of the display apparatus which concerns on this invention. It is a conceptual diagram for demonstrating the process in the display apparatus of FIG. It is a block diagram which shows the other structural example of the display apparatus which concerns on this invention. It is a figure which shows the example of a division | segmentation of the screen area | region in the display apparatus of FIG. It is a block diagram which shows the other structural example of the display apparatus which concerns on this invention.

  A display device according to the present invention includes a storage unit (storage device such as a memory) that stores video data, and reads and displays the video data from the storage unit at a pixel rate higher than the pixel rate at which the video data is input to the storage unit. Device. The storage unit is configured to divide the storage area into a plurality of buffers (that is, to secure a plurality of buffer areas) and to read / write video data while switching the buffer between reading and writing.

  As a main feature of the display device according to the present invention, the video portion to be updated is masked and written back from the read buffer to the write buffer. As a result, overtaking of data at the time of display can be prevented, and images with different time axes can be prevented from being displayed in a mixed state, and the video quality can be improved as compared with the conventional case.

  Hereinafter, as the video data, superimposition data for superimposing on the main video data is given as an example, and even when the superimposition data is graphic data (that is, still image data) or a moving image, it is handled as graphic data. In other words, the present invention will be described on the assumption that the storage unit is used as a frame memory for graphic data. The graphic data is obtained by receiving from the program information included in the broadcast signal and / or the OSD image data that can be generated from the image stored in advance in the display device, the output image data from the PC, the server on the Internet, etc. And browsing image data and photographic image data. When superimposition data is adopted as the video data, an effect of improving the video quality can be obtained even when superimposition with the main video data is performed.

  However, even if the video data is not superimposed data to be superimposed on main video data which is an example of other video data, an effect of preventing overtaking of data at the time of display can be obtained. In addition, as the video data, moving image data that is not handled as graphic data (of course, data that embeds moving image data in a part of the graphic data may be used), and the storage unit is used as a moving image. It may be used as a frame memory for image data. Regardless of whether or not it is handled as graphic data, the display screen transitions one after another for moving image data compared to still image data, so the effect of improving video quality by preventing data overtaking Is more obtainable.

  As an explanation of the present invention, FIG. 5 and FIG. 6 are first described for a display device having only one feature such as performing the above-described rewriting process, that is, a display apparatus performing a rewriting process without performing mask processing. The description will be given with reference. FIG. 5 is a block diagram illustrating a configuration example for explaining one of the features of the display device according to the present invention, and a block diagram illustrating a configuration example in which the superimposed data is written back in the configuration example of FIG. It is. FIG. 6 is a conceptual diagram for explaining processing in the display device of FIG.

  The display device 1a shown in FIG. 5 includes a storage unit 10, a bus arbitration unit 11, an update data input unit 12, an update data write unit 13, a superimposition data write back unit 14, a superimposition data read unit 15, an update data coordinate input unit 16, A blending unit (video combining unit) 18, a display data output unit 19, a main video input unit 20, and a scaling unit 21 are provided, and as described above, the video data is stored in the storage unit 10 at a pixel rate higher than the pixel rate. The video data is read from the unit 10 and displayed.

  The storage unit 10 is a storage device for temporarily storing video data. The storage unit 10 divides the storage area into a plurality of buffers, and switches the buffers between reading and writing, and video data (here, illustrated as superimposed data). It is configured to be able to read and write. Examples of the storage device include a large-scale memory having a capacity functioning as a frame memory, such as a DDR2 SDRAM (Double-Data-Rate2 Synchronous Dynamic Random Access Memory) and a DDR3 (Double-Data-Rate3) SDRAM.

  The storage unit 10 in the configuration example of FIG. 5 includes a write buffer 10a and a read buffer 10b in order to manage superimposed data. Here, the buffers are alternately switched to read / write, and the write buffer 10a and the read buffer 10b exist in the same time zone. The switching timing will be described later.

  The bus arbitration unit 11 arbitrates use authority for the storage unit 10 with respect to the write request (write request) received from the update data writing unit 13 and the read request (read request) received from the superimposed data reading unit 15. Arbitration may be used in order or may be prioritized, and it is only necessary to perform matching so as to meet each request within the memory bandwidth of the storage unit 10.

  The update data input unit 12 inputs update data (superimposed data of graphic data) of the superimposition data and passes it to the update data writing unit 13. The update data is input from, for example, an OSD LSI (or video and OSD LSI) in a format such as TMDS (Transition Minimized Differential Signaling), but the update data input unit 12 can process this in pixel units. The data is converted into parallel data and the like, and then transferred to the update data writing unit 13.

  Here, for example, when a 2K1K size video is scaled to 4K2K size and output to the display data output unit 19 at a predetermined frame rate on the display device 1a, the graphic data update portion is also within the 2K1K size range and the predetermined value. Keep the amount of information that can be transmitted within the frame rate. In addition, what is necessary is just to divide and input twice, when exceeding this information amount. The input pixel rate of the update data is the same as the input pixel rate of the main video data.

  The update data coordinate input unit 16 inputs the coordinate information of the update portion of the superimposed data and passes it to the update data writing unit 13. The coordinate information is information indicating where the graphic data input to the update data input unit 12 corresponds to the graphic coordinates to be displayed, what size it is, and the like, for example, described in the header of Patent Document 2. Indicates the contents. The coordinate information may be, for example, an (x, y) value with the upper left of the display screen being (0, 0). The coordinate information is also input from, for example, an OSD LSI as with the update data.

  The update data coordinate input unit 16 inputs such coordinate information, converts it into a memory address of the storage unit 10, and passes it to the update data writing unit 13. That is, the update data coordinate input unit 16 passes to the update data writing unit 13 information indicating which area of the input update data should be written to which memory space in the storage unit 10. It should be noted that all the update data input by the update data input unit 12 does not have to be valid, and only needs to be consistent with the coordinate information input by the update data coordinate input unit 16. It is assumed that coordinate information (which can be said to be a control value for selecting data) input by the update data coordinate input unit 16 has priority over valid / invalid on transmission data.

  The update data writing unit 13 transmits a request to write the update data to the storage area of the storage unit 10 (here, the write buffer 10a) based on the coordinate information to the bus arbitration unit 11, and according to the bus arbitration unit 11 to the write buffer 10a. Write. That is, the update data writing unit 13 writes update data to the write buffer 10a when there is a use authority. The write request may be issued by extracting only valid update data based on the coordinate information from the update data coordinate input unit 16 and designating the memory address (write address) of the write buffer 10a accordingly. In this manner, the update data writing unit 13 performs control to write the data of the update part of the graphic data into the write buffer 10a.

  The superimposition data reading unit 15 transmits a request to read the superimposition data from the storage area of the storage unit 10 (here, the read buffer 10 b) to the bus arbitration unit 11, and reads out from the read buffer 10 b according to the bus arbitration unit 11. That is, the superimposed data reading unit 15 reads the superimposed data from the read buffer 10b when there is a use authority. The read request may be issued by the superimposed data reading unit 15 specifying the memory address (read address) of the read buffer 10b.

  When the read request is for display (when the superimposition data to be blended with the main video data VF (n) is read), the read superimposition data for one frame is passed to the blending unit 18. The management of the read buffer 10b may be a method that is instructed from the outside each time, or may be a method that is instructed only at the beginning and sequentially increments the buffer number.

  Although one superimposition data reading unit 15 is illustrated, depending on the capability of the display data output unit 19, it is doubled even if it is output as one screen at four times the pixel rate of the main video data VF (n). The screen may be two screens or may be four screens at a magnification. A request to read to the read address on the storage unit 10 is issued to the bus arbitration unit 11 according to the display form of the scaling unit 21 as necessary, the data is received from the bus arbitration unit 11, and the superimposed data is output to the blending unit 18 At the same time, the superimposition data is output to the superimposition data write-back unit 14 in order to create a non-update area of the next frame.

  As described above, when the read request is for writing back, the read superimposition data (the superimposition data for one frame in the display device 1a) is transferred to the superimposition data write-back unit 14. Actually, in order to write back what is to be displayed, the superimposition data read-out unit 15 performs the superimposition data write-back unit 14 and the blend unit by one read request regardless of whether the read request is for write-back or display. The superimposition data is output to both of them.

  The superimposition data write-back unit 14 issues a request to write the superimposition data sent from the superimposition data read unit 15 to the write buffer 10a corresponding to the read buffer for the next frame via the bus arbitration unit 11, and bus arbitration Write control is performed according to the instruction of the unit 11.

  As described above, the write request is issued by the update data writing unit 13 specifying the memory address of the write buffer 10a, and the read request is issued by the superimposed data reading unit 15 specifying the memory address of the read buffer 10b. However, in order to enable such issuance, the update data writing unit 13 and the superimposed data reading unit 15 may determine in advance whether the buffer is for reading or writing at that time. However, the bus arbitration unit 11 may be configured to determine whether the buffer is for reading or writing at that time.

  The main video input unit 20 inputs the main video data VF (n) and passes it to the scaling unit 21. The main video data is input from a video (Full HD video) LSI (or a video and OSD LSI) in a format such as TMDS, for example. The main video input unit 20 can process this in parallel in units of pixels. The data is converted to data or the like and then passed to the scaling unit 21. Here, as described above, the input pixel rate of the main video data VF (n) is the same as the input pixel rate of the update data. In addition, according to the arrangement | positioning and scaling ratio of the image | video on the display panel which is not shown in figure, if needed, you may make it once write in the memory | storage part 10, and output what was read from the memory | storage part 10 to the scaling part 21. .

  The scaling unit 21 is a scaler that can scale up the main video data VF (n) to a predetermined resolution equal to or lower than the output resolution, and passes the scaled main video data to the blend unit 18. The predetermined resolution may be determined according to a predetermined setting value. For example, the display resolution may be increased to the display resolution of the display panel, or may be a resolution as required, such as 80% of the display resolution of the display panel. . When the display resolution of the display panel is not expanded, as described above, the main video data VF (n) input to the scaling unit 21 is data temporarily stored in the storage unit 10. In addition, examples of the scaling method include bilinear interpolation and Lanczos interpolation, but are not particularly limited, and any method may be adopted.

  The blending unit 18 blends (synthesizes) the superimposition data read by the superimposition data reading unit 15 and the main video data scaled by the scaling unit 21 and passes them to the display data output unit 19. The blending unit 18 performs alpha blending of the main video data and the superimposed data, transparency processing, and overwriting processing according to a code related to display control embedded in the superimposed data and an external setting, and generates data to be displayed.

  The display data output unit 19 outputs a video having a higher resolution than the input main video to a display panel (not shown). Specifically, the display data output unit 19 transmits display data to, for example, an FRC (Frame Rate Converter) provided between the display panel and a panel controller. At this time, it is converted into a format such as LVDS (Low Voltage Differential Signaling) in accordance with the connection rule and output. At this time, according to the mutual transfer capability, it may be sent at the display resolution or may be sent in parallel on two transmission paths in half.

  The frame rate conversion method in FRC includes various methods such as a method of simply reading the same frame repeatedly a plurality of times and a method of performing frame interpolation by linear interpolation between frames (linear interpolation). This FRC can improve motion blur in a hold-type display method like a liquid crystal panel. However, the display panel provided in the display device 1 a displays the combined video data output from the blend unit 18. The display panel is not limited to a liquid crystal panel, and may be any display system such as an organic electroluminescence panel, an LED (Light Emitting Diode) panel, or a plasma display panel.

  Further, in this way, the FRC is arranged downstream of the display data output unit 19 so that the main video data VF (n) is not subjected to frame rate conversion after being scaled and passed to the display data output unit 19. However, an FRC is arranged between the scaling unit 21 and the blending unit 18 and frame rate conversion is performed on the main video data VF (n) of the input resolution, and frame rate conversion is performed on the superimposed data that is graphic data. May not be applied. This is because graphic data is not necessarily compatible with FRC.

  Further, as described above, the buffers 10a and 10b are alternately switched to read / write, and the write buffer 10a and the read buffer 10b exist in the same time zone. This point will be supplementarily described. In the superimposition data write-back unit 14, the superimposition data read by the superimposition data read unit 15 is written back to the write buffer 10 a to complete the update of the superimposition data, and the final state is reached. This means that preparation is complete (however, as will be described later, in the display device 1a, the one with a different time axis is included in the final write buffer (the buffer to be the next read buffer)). Therefore, the write buffer 10 a is changed to a read buffer, and the read superimposed data is output to the superimposed data write-back unit 14 and the blend unit 18. The original read buffer 10b is also changed to a write buffer at this switching timing.

  In the configuration in which three or more buffers are secured for update data, the configuration in which three buffers are secured will be described. When the read is ready, the buffer changes from writing to reading buffer 10b. When the superimposed data is written back (that is, when it is output to the blending unit 18), a new buffer is set in the write buffer 10a and the write back is executed, and the read buffer 10b is made an unused buffer. The write buffer 10a may be set as a read buffer upon completion of the write back, and so on. Even if it is an unused buffer, this buffer will be set as a write buffer next time, so there is no need to erase internal data, and there is no problem even if the superimposition data is not maintained by refresh. .

  As described above, the superimposition data is written back in the display device 1a. However, in the display device 1a, superimposition data stored in the read buffer 10b and to be displayed includes data with different time axes. As shown in FIG. 6, a case where update data GF (n + 1) of frame F (n + 1) is input to display data DF (n) of frame F (n) will be described. As a part of the superimposition data to be displayed in the next frame F (n + 1), the superimposition read out for displaying the frame F (n) as a part of the superimposition data to be displayed in the next frame F (n + 1). By rewriting the data GF (n), the stationary portion of the superimposed data output to the F (n + 1) frame is supplemented, and the superimposed data GF (n + 1) is generated.

  As a result, the superimposition data MF (n) in the final state of the write buffer 10b (the stage to be changed for reading) includes the portion 22a of the superimposition data that has not been updated at the time of the frame F (n) and the frame F (n + 1). In addition to the updated portion 23a and the portion 24 updated only in the frame F (n) and not updated in the frame F (n + 1), the head portion 23b of the updated portion of the frame F (n) by writing back is used. Will be overwritten at the beginning of the updated portion of frame F (n + 1). As a result, the display data DF (n + 1) of the frame F (n + 1) is displayed in the same manner because the superimposed data is superimposed on the main video data.

  Overwrite processing with overtaking in the storage area (and thereby overtaking at the time of display) is different because the processing speed of writing and reading is different as in the case described with reference to FIGS. Occur. In order to avoid such a situation, the main feature of the present invention is to perform mask processing on the superimposed data to be written back.

  The display device of the present invention that performs such mask processing will be described with reference to FIGS. 7 is a block diagram showing an example of the configuration of the display device according to the present invention, FIG. 8 is a diagram showing an example of the data storage state of the storage unit in the display device of FIG. 7, and FIG. 9 is the display device of FIG. It is a conceptual diagram for demonstrating the process in. However, among the components of the display device 1 of the configuration example shown in FIG. 7, the description of the same parts as those of the display device 1 a of FIG. 5 is omitted.

  The display device 1 according to the present invention includes a mask unit that masks a video portion (video region) to be updated (corrected) among video data read from a read buffer (read buffer 10b). An example of the mask unit is a superimposed data mask unit 17 that employs superimposed data as the video data. The superimposition data mask unit 17 performs a mask process on the video portion of the update data from the superimposition data based on the coordinate information of the update data coordinate input unit 16.

  More specifically, first, the superimposition data reading unit 15 in the display device 1 outputs the superimposition data in the read buffer 10b to the blending unit 18 and also creates a non-update area for the next frame. Also output. Then, the update data coordinate input unit 16 in the display device 1 superimposes graphic coordinate information indicating where the region to be updated in the next frame (that is, the video portion to be updated) is displayed. This is transmitted to the data mask unit 17.

  The superimposition data mask unit 17 receives the superimposition data output from the superimposition data reading unit 15, and based on the coordinate information received from the update data coordinate input unit 16, the superimposition data mask unit 17 marks (writes) the data in the display update scheduled area of the next frame. A mask process is performed, for example, by adding a mark indicating return. Or, conversely, the data in the non-updated area is marked (a mark indicating not to be written back), and the superimposed data is sent to the superimposed data writing back unit 14. If the mark is consistent with the process in the superimposed data write-back unit 14, the updated part of the superimposed data can be masked (in other words, thinned out) by the mask process.

  The display device 1 includes a write-back unit that writes back video data that has been read from the read buffer 10b and subjected to mask processing to a write buffer (write buffer) 10a. An example of this write-back unit is a superimposed data write-back unit 14 that employs superimposed data as the video data.

  The superimposed data write-back unit 14 writes the superimposed mask data processed by the superimposed data mask unit 17 back to the write buffer 10 a of the storage unit 10. Specifically, the superimposed data write-back unit 14 issues a request to write the data sent from the superimposed data mask unit 17 to the write buffer 10a corresponding to the buffer for reading the next frame through the bus arbitration unit 11. Then, writing is performed according to the instruction of the bus arbitration unit 11. At this time, even if a write request is issued to all of the marked data using a MASK signal for a general memory, it is identified and a write request is issued only to a portion that needs to be written. It may be issued. Note that if the update data of the next frame is before being written by the update data writing unit 13, the update data is overwritten, so no matter what is written in the update area, there is no problem.

  Then, based on the coordinate information received from the update data coordinate input unit 16, the update data writing unit 13 stores the video data of the video part to be updated (this data) in the portion masked by the superimposed data mask unit 17 in the write buffer 10 a. In the example, update data that is the superimposition data of the video portion to be updated) is written.

Details of the display processing in the display device 1 having the above-described configuration example will be described.
A case where the update data GF (n + 1) of the frame F (n + 1) is input to the display data DF (n) of the frame F (n) shown in FIG.

  As a part of the superimposition data to be displayed on the next frame F (n + 1), the update data input for the frame F (n) is applied to the frame F from the read buffer 10b in the state shown in FIG. By writing back the superimposition data GF (n) read out for the display of (n), the stationary portion of the superimposition data output to the F (n + 1) frame is compensated to generate the superimposition data GF (n + 1).

  However, as described with reference to FIG. 6, data with different time axes is included in the superimposed data as it is, so that in the superimposed data mask unit 17, the superimposed data GF (n) read out by the superimposed data reading unit 15. Then, the update portion of the next frame is detected based on the coordinate information input from the update data coordinate input unit 16 and the update portion is masked, and then the superimposed data write-back unit 14 executes the write-back. As a result, the area corresponding to the update portion in the frame F (n + 1) is masked from the write buffer 10a in the state shown in FIG. 8, and the update data corresponding to the frame F (n + 1) is input. At this time, the data can be written in the masked portion, and the write buffer 10a in the state shown in FIG.

  More specifically, the write buffer 10a in the state shown in FIG. 8 stores the superimposed data MF (n) in the final state of the write buffer 10b shown in FIG. The superimposition data MF (n) is included only in the portion 22 of the superimposition data that has not been updated at the time of the frame F (n), the portion 23 that has been updated in the frame F (n + 1), and the frame F (n). In the frame F (n + 1) that has been updated, it becomes the portion 24 that has not been updated, the overwriting process described in FIG. 6 does not occur, and all the time axes are the same in the superimposed data (that is, the frame F (n + 1)) (Superimposed data to be displayed). As a result, the display data DF (n + 1) of the frame F (n + 1) can be displayed in the same manner because the superimposed data is superimposed on the main video data.

  8 and 9, the update data is shown as 2K1K size, and the superimposition data and the scaled main video data are shown as 4K2K size. This is because, even when superimposing data of 4K2K size is finally superposed, the update data input unit 12 only needs to input data as a small update part as update data, so data within the range of 2K1K size is sufficient. is there. By adopting a configuration in which coordinate information is input separately without fixing the update data write coordinates, for example, even when the mouse cursor crosses an area, it is possible to update at a high frame rate such as an input frame rate of 60 Hz. . If update data is input at, for example, 60 Hz, it is possible to realize display processing of superimposed data at 4 K2K size at 60 Hz by input within a range of information amount of 2K1K size with respect to arbitrary coordinates without reducing the frame rate. Also, the amount of information may exceed the amount of information at the initial stage of displaying graphic data. In such a case, if updating with this update data is repeated, 4K2K-sized superimposed data is completed.

  Next, including a description of this initial stage, a series of flows of the initial graphic data (initial screen data) generation process, the superimposed data display process, and the synchronization process in the display device 1 of FIG. 7 will be briefly described. .

(Initial graphic data creation process)
First, the blend unit 18 is set to display only main video data. Then, the write buffer 10 a is set for the update data writing unit 13 and the superimposed data writing back unit 14. For example, it may be set by the head and size of the write address. Further, the read buffer 10 b is set for the superimposed data reading unit 15. Here, for example, it may be set by the head and size of the read address.

  The update data input unit 12 inputs the data for the entire screen as the update data by dividing it into the required number of times. At this time, even if the write back function to the storage unit 10 is used by using the function of the superimposition data mask unit 17, the write buffer 10a is not moved for each frame without using the write back function, and the superimposition data for the entire screen is stored. You may create it. Then, the update data writing unit 13 writes the update data to the write address on the storage unit 10 based on the coordinate information from the update data coordinate input unit 16 and the relative coordinates of the write buffer 10a.

  The superimposition data write-back unit 14 writes the superimposition data of the portion where the mask processing is not performed on the write address on the write buffer 10a by the coordinate information from the update data coordinate input unit 16 and the relative coordinates of the write buffer 10a. . The readout and mask processing of this part is executed by the superimposed data reading unit 15 and the superimposed data mask unit 17 for writing back. The increment (switching update) of the write buffer 10a / read buffer 10b may be a size specified, and may be an automatic increment by hardware or an increment of every frame by software.

(Superimposed data display processing)
Next, the blending unit 18 is set to output blended main video data and superimposed data. Also, if the buffer is used in a fixed manner in the initial graphic data creation process, it is set to increment.

  Next, the update data input unit 12 inputs necessary update data, and the update data coordinate input unit 16 inputs coordinate information for the update data. Thereafter, the update data writing unit 13 writes the update data to the write address on the write buffer 10a based on the coordinate information of the update data coordinate input unit 16 and the relative coordinates of the write buffer.

  The superimposition data write-back unit 14 writes the superimposition data of the portion that has not been subjected to the mask processing to the write address on the write buffer 10a based on the coordinate information from the update data coordinate input unit 16 and the relative coordinates of the write buffer 10a. The readout and mask processing of this part is executed by the superimposed data reading unit 15 and the superimposed data mask unit 17 for writing back. The increment of the write buffer 10a / read buffer 10b may be a size specified and may be an automatic increment by hardware or an increment of every frame by software.

  Then, the blending unit 18 alpha blends, overlays, and transmits the main video data and the superimposed data according to the code relating to the display control embedded in the external setting and the superimposed data, and outputs them to the display data output unit 19.

(Synchronous processing)
The write timing depends on the input, and the read timing depends on the output synchronization created from the input synchronization based on the device configuration. The bus arbitration unit 11 is designed in consideration of each timing, and performs arbitration.

  As described above, in the display device according to the present invention, it is possible to prevent overtaking of data on the storage area by dividing the storage area into two or more buffers and switching between writing and reading and performing mask processing. Thus, overtaking of data at the time of display can be prevented, and it can be prevented that images of different time axes are mixedly displayed. Therefore, for example, by inputting only update data of an arbitrary coordinate of 2K1K size, the superimposition data can be output as a high-quality video with an input frame rate (60 fps) of 4K2K. And in the video superimposing technique of the present invention, even if the superimposition data is superimposed on the main video by thinning out the updated portion from the displayed one and writing it back to the memory, the display video is not disturbed, and a smooth moving image and Become.

  In the present invention, since the frame rate is not lowered as in the technique described in Patent Document 1, it is possible to cope with the case where moving image data is adopted as the video data. Specifically, in the present invention, when the superimposition data corresponding to the resolution of the display panel written on the storage unit 10 is read out and output, the superimposition data mask unit 17 By the action of the update data writing unit 13 and the superimposed data writing back unit 14, the data for the resolution of the display panel (for example, data for 4K2K) is continuously developed in the storage area according to the output frame rate, and display preparation can be performed. This makes it possible to synthesize a moving image that is not limited to a still image into a main video.

  As described above, the present invention can also cope with a moving image, and creates 4K2K size data by inputting data of 2K1K size (within the range of 2K1K size), for example, without displaying data being written to the write buffer, When completed, the display is switched to the reading buffer. Thus, in the present invention, unlike the technique described in Patent Document 2 in which data in the middle of writing is displayed, it is possible to synthesize a moving image smoothly into a main video, not just a still image.

  The present invention is not limited to displaying 2K1K size graphic data and main video data on a 4K2K size display panel. For example, 2K1K size graphic data and main video data are displayed on a 16K8K size display panel. The present invention can be similarly applied to the case where 4K2K size graphic data and main video data are displayed on an 8K4K size display panel, and the case where 4K2K size graphic data and main video data are displayed on a 16K8K size display panel.

  As described above, in the present invention, the video data to be stored in the storage unit 10 may not be superimposition data, and in that case, a blend that is an example of a superimposition unit that superimposes superimposition data on main video data. The main video input unit 20 and the scaling unit 21 that perform processing related to the main video data may not be included.

  Next, another configuration example of the display device according to the present invention will be described with reference to FIGS. FIG. 10 is a block diagram showing another configuration example of the display device according to the present invention, and FIG. 11 is a conceptual diagram for explaining processing in the display device of FIG. However, among the components of the display device 4 of the configuration example shown in FIG. 10, the description of the same parts as those of the display device 1 of FIG. 7 is omitted.

  10 includes the main video data writing unit 40 and the main video data reading unit 41 in the display device 1 of FIG. Thus, the main video data needs to be once written in the storage unit 10 depending on the scaling size and position of the main video, such as display at 80% of the display resolution of the display panel described above.

  Specifically, the main video data writing unit 40 writes the main video data VF (n) to the storage unit 10 through the bus arbitration unit 11, and the main video data reading unit 41 bus-adjusts the main video data VF (n). Read through the unit 11 and output to the scaling unit 21. The scaling unit 21 may be provided before the main video data writing unit 40. For the main video data VF (n), it is assumed that the buffer address is set in the same manner as the superimposed data. However, when reading does not overtake writing, reading and writing may be the same buffer. The buffer for the main video data may be secured in an area different from the write buffer 10a and the read buffer 10b for update data, or 3 as the write buffer 10a and the read buffer 10b for update data. When two or more buffers are used, a surplus buffer may be allocated for main video data.

  In the display device 4, for example, for the frame F (n), the main video data VF (n) of 2K1K size is scaled to a predetermined size to be the main video data VSF (n). The superimposition data MF (n) of the frame F (n) can be superimposed on it and output as display data DF (n). Here, the update data GF (n + 1) for the frame F (n + 1) is not written in the read buffer 10b when the frame F (n) is read, and thus is not included in the superimposed data MF (n).

  Next, another configuration example of the display device according to the present invention will be described with reference to FIGS. 12 is a block diagram showing another configuration example of the display device according to the present invention, and FIG. 13 is a diagram showing an example of division of the screen area in the display device of FIG. However, among the constituent elements of the display device 6 of the configuration example shown in FIG. 12, the description overlapping with the description of the display device 1 of FIG. 7 and the display device 4 of FIG. Illustration of elements is also omitted.

  The display device 6 of FIG. 12 is the same as the display device 4 of FIG. 10 except that the display data output unit 19 has the same restrictions (band limitation) as the input side and includes first to fourth display data output units 69a to 69d. To do. As shown in FIG. 13A, the first to fourth display data output units 69a to 69d are configured so that each screen area is controlled by being divided into four areas in a strip shape. As shown in FIG. 4, each of the display panels is controlled by being divided into four areas in a cross shape. With such a configuration, the main video data can be temporarily written in the storage unit 10 depending on the scaling size and position of the main video. In the display devices 1 and 4 of FIG. 7 and FIG. 10, the pixel rate itself is increased by, for example, four times. However, in order to secure the operation speed at the input pixel rate, for example, parallel processing is being attempted through four paths.

  As a specific configuration for performing such display, in the display device 6, the superimposition data reading unit 15 is divided into four to be first to fourth superimposition data reading units 65 a to 65 d, and the main video data reading unit 41. Are divided into four to form first to fourth main video data reading sections 61a to 61d. In accordance with this, in the display device 6, instead of the blending unit 18, the first blending unit 68 a that receives the outputs of the first superimposed data reading unit 65 a and the first main video data reading unit 61 a, the second superimposed data. A second blending unit 68b that receives the outputs of the reading unit 65b and the second main video data reading unit 61b; a third blending unit 68c that receives the outputs of the third superimposed data reading unit 65c and the third main video data reading unit 61c; And a fourth blending unit 68d for receiving the outputs of the fourth superimposed data reading unit 65d and the fourth main video data reading unit 61d. The outputs of the first to fourth blending units 68a to 68d are configured to be input to the first to fourth display data output units 69a to 69d, respectively.

  Note that the first to fourth superimposition data reading units 65a to 65d pass the superimposition data of the corresponding regions, not the entire frame, to the superimposition data mask unit 17, and the superimposition data mask unit 17 The update portion may be masked so that the superimposed data write-back unit 14 writes back the superimposed data for each area.

  Next, another configuration example of the display device according to the present invention will be described with reference to FIG. FIG. 14 is a block diagram showing another configuration example of the display device according to the present invention. However, the description of the components of the display device 8 of the configuration example shown in FIG. 14 that are the same as those of the display device 1 of FIG. 7 and the display device 6 of FIG. 10 is omitted. Also in this configuration example, the configuration as shown in FIG. 12 can be applied.

  The display device 8 in FIG. 14 is configured such that update data and main video data are input in a time division manner in the display device 4 in FIG. Therefore, the display device 8 is provided with a data input unit 80 instead of the update data input unit 12 and the main video input unit 20. The data input unit 80 inputs the update data and the main video data by time division at a double of the output frame rate to the display data output unit 19. For example, in the data input unit 80, update data GF (n + 2), main video data VF (n + 1), update data GF (n + 1), update data, and main video data VF (n), all of 2K1K size, They are entered in numerical order.

  Further, the display device 8 is provided with an update data coordinate input unit 82 instead of the update data coordinate input unit 16 and a main video / update data dividing unit 81 for separating main video data and update data. Yes. The main video / update data dividing unit 81 separates the update data and the main video data, and outputs them to the update data writing unit 13 and the main video data writing unit 40, respectively. Coordinate information output from the update data coordinate input unit 82 is used to separate the update data and main video data. The update data coordinate input unit 82 receives not only the coordinate information described for the update data coordinate input unit 16 but also information for distinguishing the input update data from the main video data.

DESCRIPTION OF SYMBOLS 1,1a, 4,6,8 ... Display apparatus, 10 ... Memory | storage part, 11 ... Bus arbitration part, 12 ... Update data input part, 13 ... Update data writing part, 14 ... Superimposition data write-back part, 15 ... Superimposition data Reading unit, 16 ... update data coordinate input unit, 17 ... superimposed data mask unit, 18 ... blend unit, 19 ... display data output unit, 20 ... main video input unit, 21 ... scaling unit, 40 ... main video data writing unit, 41 ... main video data reading unit, 61a ... first main video data reading unit, 61b ... second main video data reading unit, 61c ... third main video data reading unit, 61d ... fourth main video data reading unit, 65a ... First superimposed data reading unit, 65b ... second superimposed data reading unit, 65c ... third superimposed data reading unit, 65d ... fourth superimposed data reading unit, 68a ... first blur 68b ... second blending unit, 68c ... third blending unit, 68d ... fourth blending unit, 69a ... first display data output unit, 69b ... second display data output unit, 69c ... third display data output unit 69d ... fourth display data output unit, 80 ... data input unit, 81 ... main video / update data division unit, 82 ... update data coordinate input unit.

Claims (3)

A display device comprising a storage unit for storing video data, and reading and displaying the video data from the storage unit at a pixel rate greater than a pixel rate for inputting the video data to the storage unit,
The storage unit is configured to divide a storage area into a plurality of buffers, and to read and write video data while switching the buffer for reading and writing,
The display device masks a video portion to be updated out of video data read from a read buffer, and the video data subjected to mask processing in the mask portion to a write buffer. A write-back unit for writing back, and an update data writing unit for writing update data, which is video data of the video part to be updated, into a part masked by the mask unit in the buffer for writing. Characteristic display device.   The display device according to claim 1, further comprising a superimposing unit that superimposes the video data on other video data.   The display device according to claim 2, wherein an input pixel rate of the other video data is the same as an input pixel rate of the update data.

Images