JP6155564B2 - Video display device and video display method - Google Patents

Description

  The present invention relates to an image display apparatus and an image display method that can handle a plurality of types of images.

  Currently, displays such as computer terminals have a wide variety of display positions and display sizes (resolutions) of images on the screen and input images (video signals). For this reason, a highly versatile multi-scan display capable of handling all images with a single display has come to be used. That is, when there is only one resolution of the video input to the display, the resolution conversion adjustment value can be fixed. On the other hand, when a plurality of videos having different resolutions are input, it is necessary to identify the resolution of the video and perform resolution conversion so as to match the resolution of the display device.

  Patent Document 1 discloses an automatic adjustment device for a multi-scan display. In this automatic adjustment apparatus, the horizontal / vertical period of the input video, the start position and the end position of the video display period are measured, and the display size and the display position are calculated from the measurement result so as to match the display timing of the display. This process eliminates the need for a device for adjusting the display size and display position information of the video in the memory and adjustment time, and eliminates the need for manual adjustment by the user even when an unknown video is input.

Japanese Patent Laid-Open No. 05-035240

  In the automatic adjustment device of Patent Document 1, an input image is measured, waits until information such as a horizontal / vertical display position is determined, and after the determination, calculation is performed so as to match the display timing of the display. As for the confirmation condition, information such as the horizontal / vertical display position is fetched at a predetermined interval, and the case where the fetched value is the same as the previous time is regarded as definite. For this reason, when the input video is switched, it takes time to determine and calculate the information of the video after the switching. As a result, a distorted video is displayed until the video after switching is normally displayed on the display.

  For example, as shown in FIG. 8, when a plurality of types of videos A, B, C, and D having different video information (horizontal / vertical synchronization signal period, etc.) are input, the fourth to seventh frames are displayed. Display image is disturbed. Specifically, as shown by a cross in the figure, the display image on the display starts to be disturbed from the fourth frame in which the input image changes from A to B. After the sixth frame, the video D is stable. However, after the input video matches the information of the previous video, the video information is determined and displayed on the display from the determined video. Also, the display image on the display is disturbed for the seventh frame.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a video display device and a video display method capable of suppressing disturbance of a display video on a display even when a plurality of types of video are input. Is to provide.

In order to solve the above problems, the video display device according to the embodiment of the present invention is information of each frame of the input video, and includes at least a horizontal / vertical synchronization signal, a clock signal cycle, a position and a size of a data enable signal. A video information measuring unit for measuring video information consisting of one, a frame memory for storing the input video, a video information comparing unit for comparing a measurement result of the video information measuring unit with a previous measurement result, When the comparison result of the video information comparison unit does not match, the write control unit that alternately writes the input video to a plurality of memory areas in which the input video immediately before the mismatch is not stored among the memory areas in the frame memory If the comparison result of the video information comparison unit does not match, the read control for reading the input video immediately before the mismatch from the frame memory is performed. Comprising a part, and a display unit for displaying an input image read by the read control unit, the write control unit, the case the comparison result of the image information comparing unit does not match the number of mismatches whether an even number And controlling the order of writing the input video to a plurality of memory areas in which the input video just before the mismatch is not stored among the memory areas in the frame memory, and the read control unit is configured to compare the video information If the comparison result of the part does not match, the display is controlled by controlling the order in which the input video is read from the frame memory depending on whether the number of mismatches is one or more, and whether the number of mismatches is even or odd. While the comparison result of the video information comparison unit does not match, the input video immediately before the mismatch is displayed, and after the comparison result of the video information comparison unit matches, Without missing the oldest input image has, and displaying the sequentially input image.

  The display unit continues to display the input video before switching until the calculation for properly displaying the input video after switching is completed, and displays the input video after the switching when the calculation is completed. May be.

  A write number determining unit that determines a write number of the frame memory using a comparison result of the video information comparing unit, the number of mismatches of the video information, and a write number of one frame before; The input video may be written to the write number determined by the write number determination unit.

  Further, the readout number of the frame memory is determined using the comparison result of the video information comparison unit, the number of mismatches of the video information, the information flag when the previous readout number is determined, and the readout number of the previous frame. A read number determining unit may be provided, and the read control unit may read the input video from the read number determined by the read number determining unit.

  The frame memory may have a memory area that can store the input video for four frames.

  Further, when comparing the measurement results for N frames, the frame memory may have a memory area capable of storing the input video for N + 2 frames.

In order to solve the above-described problem, an image display method according to an embodiment of the present invention is information on each frame of an input image, and includes at least a horizontal / vertical synchronization signal, a cycle of a clock signal, a position and a size of a data enable signal. When the video information measurement step for measuring the video information consisting of one video image, the video information comparison step for comparing the measurement result of the video information measurement step with the previous measurement result, and the comparison result of the video information comparison step are inconsistent, A writing control step of alternately writing the input video to a plurality of memory areas in which the input video immediately before the mismatch is not stored among the memory areas in the frame memory for storing the input video; and the video information If the comparison result of the comparison step does not match, the input video immediately before the mismatch is read from the frame memory. And to read control step, and a display step of displaying an input image read by the reading control step, and in the writing control step, when the image information comparison result of comparing step mismatch, the number of mismatches The order of writing the input video to a plurality of memory areas in which the input video just before the mismatch is not stored in the memory area in the frame memory depending on whether it is an even number or not, in the reading control step, When the comparison result of the video information comparison step does not match, the order of reading the input video from the frame memory is controlled depending on whether the number of mismatches is 1 or 2 or more and whether the number of mismatches is even or odd. In the display step, before the comparison result of the video information comparison step does not match, immediately before the mismatch Continues to display the input image, after the image information comparison result of comparing step matches, without missing the oldest input image matching, and displaying the sequentially input image.

  According to the present invention, it is possible to provide a video display device and a video display method capable of suppressing disturbance of a display video on a display even when a plurality of types of video are input.

It is a block diagram which shows the structural example of the video display apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structural example of the frame memory which concerns on embodiment of this invention. It is a flowchart which shows the operation example of the writing control of the video display apparatus concerning embodiment of this invention. It is a flowchart which shows the operation example of read-out control of the video display apparatus concerning embodiment of this invention. It is a figure for demonstrating the operation example 1 which concerns on embodiment of this invention, Comprising: (a) is an input image | video, (b) is the image | video of each bank of a frame memory, (c) is a display image | video of a display. It is a figure for demonstrating the operation example 2 which concerns on embodiment of this invention, Comprising: (a) is an input image | video, (b) is the image | video of each bank of a frame memory, (c) is a display image | video of a display. It is a figure for demonstrating the operation example 3 which concerns on embodiment of this invention, Comprising: (a) is an input image, (b) is the image | video of each bank of a frame memory, (c) is a display image | video of a display. It is a figure which shows the input image in a prior art, and the display image of a display.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

≪Configuration example≫
FIG. 1 is a configuration diagram illustrating a configuration example of a video display device according to an embodiment of the present invention. This video display device is a device that can handle a plurality of types of video, and as shown in FIG. 1, a video information measurement unit 11, a video information storage unit 12, a video information comparison unit 13, and a writing number determination. Unit 14, write control unit 15, frame memory 16, read number determination unit 17, read control unit 18, display timing deriving unit 19, and display 20. Multiple types of video are videos with different display timings. The display timing includes an image enlargement / reduction ratio, a display position, a horizontal / vertical synchronization signal cycle, and the like.

  The input video is supplied to the video information measuring unit 11 and the writing control unit 15.

  The video information measuring unit 11 measures video information that is information of each frame of the input video. The video information includes the horizontal / vertical synchronization signal, the position and size of the data enable signal, the cycle of the clock signal, and the like.

  The video information storage unit 12 stores the measurement result (video information) of the video information measurement unit 11 for each bank of the frame memory 16 in which the video to be measured is stored. The bank here means a memory area for storing one frame of video, and does not necessarily match the bank terminal of the frame memory 16.

  In the present embodiment, a frame memory 16 having a memory area capable of storing video for four frames is used. Specifically, as shown in FIG. 2, a frame memory 16 having four banks (1) to (4) is used, and one bank is used as a memory area for one frame. The number of banks of the frame memory 16 may be four or more, but the most preferable number is four. When the number of banks is four, the number of video information stored in the video information storage unit 12 may be only four frames.

  The video information comparison unit 13 compares the measurement result of the video information measurement unit 11 with the previous measurement result. That is, the video information of the input video and the previous video is compared to determine whether they match or do not match.

  The write number determination unit 14 determines the write number BW for writing the input video to the frame memory 16 using the comparison result of the video information comparison unit 13, the number of mismatches of the video information, and the write number BW one frame before.

  The write control unit 15 writes the input video to the write number BW determined by the write number determination unit 14. For example, when the comparison result of the video information comparison unit 13 does not match, the input video is alternately written to a plurality of memory areas in the memory area in the frame memory 16 where the input video immediately before the mismatch is not stored. It has become.

  The read number determination unit 17 uses the comparison result of the video information comparison unit 13, the number of mismatches of the video information, the information flag (R_FLG) when the previous read number BR is determined, and the read number BR one frame before, A read number BR for reading the input video from the frame memory 16 is determined.

  The display timing deriving unit 19 displays the display timing (video enlargement / reduction ratio, display position, horizontal / horizontal) displayed on the display 20 from the video information stored in the readout number BR determined by the readout number determination unit 17. (Vertical synchronization signal cycle) is calculated. When the video information of the video read immediately before and the video information read from now on are the same, the previous display timing may be set as the current display timing without calculation.

  The read control unit 18 reads the video of the read number BR determined by the read number determination unit 17 at the display timing derived by the display timing deriving unit 19 and outputs it to the display 20. For example, when the comparison result of the video information comparison unit 13 does not match, the input video immediately before the mismatch is read from the frame memory 16.

  The display 20 displays the input video read by the read control unit 18. Until the calculation for properly displaying the input video after the switching is completed, the input video before the switching is continuously displayed, and when the calculation is completed, the input video after the switching is displayed.

<< Operation example 1 >>
FIG. 3 is a flowchart showing an example of write control operation of the video display apparatus according to the embodiment of the present invention. FIG. 4 is a flowchart showing an operation example of readout control of the video display apparatus according to the embodiment of the present invention. Examples of these operations will be described with reference to FIG. FIG. 5A shows a case where a plurality of types of input images A and D are input. FIG. 5B shows an image of each bank of the frame memory. A thick frame in FIG. 5B means that the same input video is displayed. FIG. 5C shows a display image on the display 20.

  The operation of the display 20 after the power is turned on (step 01) is as follows.

(A) When video of the first frame is input (a) Write control First, measurement of video information of the input video (first frame) is started (step 02). Specifically, the video information includes a horizontal / vertical synchronization signal, a clock signal cycle, and a position and size of a data enable signal.

  Next, the write number BW of the frame memory 16 is incremented, for example, in the order of BW = (1) → (2) → (3) → (4) → (1) →... (Step 03). After (4), return to (1). (1) to (4) are banks (1) to (4). Here, since it is the first frame, the write number BW = (1).

  Next, the input video is written to the write number BW of the frame memory 16 (step 04). Here, since the write number BW = (1), the input video is written into the bank (1) of the frame memory 16.

  Next, it is determined whether or not the input video and the previous video have the same measurement result or there is no previous measurement result (step 05). Here, since it is the first frame, it is determined that there is no previous measurement result.

  Next, it is determined whether the measurement results of the previous video and the previous video are the same, or whether there is no previous measurement result (step 07). Here, since it is the first frame, it is determined that there is no measurement result to be compared.

  The process proceeds to the next frame (second frame) below.

(B) Read control R_FLG is initialized to 0 (step. 01), and it is determined whether or not video of two frames or more is stored in the frame memory 16 (step. 11). Here, since the input of the first frame of video is started, the video of more than two frames is not yet stored in the frame memory 16, and therefore the read control is not executed.

(B) When video of second frame is input (a) Write control Measurement of video information of input video (second frame) is started (step 02). The write number BW of the frame memory 16 is (1) +1 and BW = (2) (step 03). The input video is written into the bank (2) of the frame memory 16 (step 04). It is determined that the measurement results of the present (second frame) and the previous one (first frame) are the same (step 05). Since it is the second frame, it is determined that there is no measurement result to be compared (step 07). The process proceeds to the following next frame (third frame).

(B) Read Control At the time when the input of the second frame video is started, the video is not stored in the frame memory 16 yet, so the read control is not executed (step 11).

(C) When video of third frame is input (a) Write control Measurement of video information of input video (third frame) is started (step 02). The write number BW of the frame memory 16 is (2) +1 and BW = (3) (step 03). The input video is written into the bank (3) of the frame memory 16 (step 04). It is determined that the measurement results of the present (third frame) and the previous (second frame) are the same (step 05). It is determined that the measurement results of the previous one (second frame) and the second previous (first frame) are the same (step 07). The process proceeds to the following next frame (fourth frame).

(B) Read control First, the read number BR of the frame memory 16 is incremented in the order of, for example, BR = (1) → (2) → (3) → (4) → (1) →. After (4), return to (1). Here, since it is the first reading, the reading number BR = (1) (step 12).

  Next, the display timing of the display 20 is calculated based on the video information of the video having the readout number BR (step 13). Here, the display timing of the display 20 is calculated based on the measurement result of the first frame (video enlargement / reduction ratio, display position, horizontal / vertical synchronization signal cycle). If the measurement result of the video of the immediately preceding read number BR and the video of the current read number BR are the same, the immediately preceding display timing may be set as the current display timing without calculation.

  Next, from the read number BR of the frame memory 16, step. The video is read at the display timing of 13 (step 14). Here, the video of the first frame is read from the bank (1).

  Next, the read video is displayed on the display 20 (step 15). Here, the first frame image is displayed.

  Next, it is determined whether or not the input video and the previous video have the same measurement result or there is no previous measurement result (step 05). This step is a step of writing control step. This is the same as 05. Here, it is determined that the measurement results of the present (third frame) and the previous (second frame) are the same.

  Next, it is determined whether the measurement results of the previous video and the previous video are the same and R_FLG is 0 (step 17). Here, it is determined that the measurement result of the previous frame (second frame) and the previous frame (first frame) are the same and R_FLG is 0.

  The process proceeds to the following next frame (fourth frame).

(D) When the fourth frame video is input (a) Write control Measurement of video information of the input video (fourth frame) is started (step 02). The write number BW of the frame memory 16 is (3) +1 and BW = (4) (step 03). The input video is written into the bank (4) of the frame memory 16 (step 04). It is determined that the measurement results of the present (fourth frame) and the previous one (third frame) are different (step 05). If the number of mismatches is an even number, the write number BW = BW−2 of the frame memory 16 is set (step 06). The number of mismatches is the number of times that the video information is determined to be mismatched, that is, the number of times that the measurement results are determined to be different. If the mismatch is interrupted (matched), the number of mismatches is reset to zero. Here, since the number of mismatches is one, the write number BW of the frame memory 16 is BW = (4) as it is. The process proceeds to the following next frame (fifth frame).

(B) Read Control The read number BR of the frame memory 16 is (1) +1 and BR = (2) (step 12). The display timing of the display 20 is calculated based on the measurement result of the second frame (step 13). Since the second frame has the same measurement result as the first frame, the display timing of the first frame may be used without calculation. The video of the second frame is read from the bank (2) of the frame memory 16 (step 14). The second frame image is displayed on the display 20 (step 15). It is determined that the current (fourth frame) and the previous (third frame) measurement results are different (step 05). Here, when the number of mismatches is one, the read number BR of the frame memory 16 remains unchanged, and R_FLG = 0 is set (step 16). If the number of mismatches is 2 or more, the read number BR of the frame memory 16 is set to BR-1 and R_FLG = 0 (step 16). Here, since the number of mismatches is one, the read number BR of the frame memory 16 remains as BR = (2) and R_FLG = 0. The process proceeds to the following next frame (fifth frame).

(E) When video of the fifth frame is input (a) Write control Measurement of video information of the input video (fifth frame) is started (step 02). The write number BW of the frame memory 16 returns to (1) when 1 is added to (4), so BW = (1) (step 03). The input video is written into the bank (1) of the frame memory 16 (step 04). It is determined that the measurement results of the present (5th frame) and the previous (4th frame) are the same (step 05). It is determined that the measurement results of the previous one (fourth frame) and the second previous (third frame) are different (step 07). If the number of mismatches up to the previous video is even, the write number BW = BW + 1 in the frame memory 16 is set (step 08). Here, since the number of mismatches up to the previous video is one, the write number BW of the frame memory 16 is (1) as it is. The process proceeds to the following next frame (sixth frame).

(B) Read Control The read number BR of the frame memory 16 is (2) +1 and BR = (3) (step 12). The display timing of the display 20 is calculated based on the measurement result of the third frame (step 13). The video of the third frame is read from the bank (3) of the frame memory 16 (step 14). The third frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (5th frame) and the previous (4th frame) are the same (step 05). The measurement results of the previous one (fourth frame) and the second previous (third frame) are different, and it is determined that RFLG = 0 (step 17).

  Here, the following processing is performed based on the number of mismatches up to the previous video and R_FLG. That is, when the number of mismatches is an odd number, the read number BR of the frame memory 16 remains unchanged and R_FLG = 0 is set (step 18). On the other hand, when the number of mismatches is an even number, when R_FLG = 0, the read numbers BR = BR + 1 and R_FLG = 1 are set in the frame memory 16 (step 18). When the number of mismatches is an even number, and R_FLG = 1, the read number BR of the frame memory 16 is set to BR-2 and R_FLG = 2 (step 18). If the number of mismatches is an even number, and R_FLG = 2, the read number BR = BR + 1 and R_FLG = 0 are set in the frame memory 16 (step 18). Here, since the number of mismatches up to the previous video is one, the read number BR of the frame memory 16 is (3) as it is. The process proceeds to the following next frame (sixth frame).

(F) When video of 6th frame is input (a) Write control Measurement of video information of input video (6th frame) is started (step 02). The write number BW of the frame memory 16 is (1) +1 and BW = (2) (step 03). The input video is written into the bank (2) of the frame memory 16 (step 04). It is determined that the measurement results of the present (sixth frame) and the previous one (fifth frame) are the same (step 05). It is determined that the measurement results of the previous one (fifth frame) and the second previous (fourth frame) are the same (step 07). The process proceeds to the following next frame (seventh frame).

(B) Read Control The read number BR of the frame memory 16 is (3) +1 and BR = (4) (step 12). The display timing of the display 20 is calculated based on the measurement result of the fourth frame (step 13). The fourth frame image is read from the bank (4) of the frame memory 16 (step 14). The fourth frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (sixth frame) and the previous one (fifth frame) are the same (step 05). It is determined that the measurement results of the previous one (fifth frame) and the second previous (fourth frame) are the same and R_FLG = 0 (step 17). The process proceeds to the following next frame (seventh frame).

(G) When video of seventh frame is input (a) Write control Measurement of video information of input video (seventh frame) is started (step 02). The write number BW of the frame memory 16 is (2) +1 and BW = (3) (step 03). The input video is written into the bank (3) of the frame memory 16 (step 04). It is determined that the measurement results of the present (seventh frame) and the previous one (sixth frame) are the same (step 05). It is determined that the measurement results of the previous one (sixth frame) and the second previous (fifth frame) are the same (step 07). The process proceeds to the next frame (eighth frame) described below.

(B) Read Control The read number BR of the frame memory 16 is (4) +1 and BR = (1) (step 12). The display timing of the display 20 is calculated based on the measurement result of the fifth frame (step 13). The fifth frame image is read from the bank (1) of the frame memory 16 (step 14). The fifth frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (seventh frame) and the previous one (sixth frame) are the same (step 05). It is determined that the measurement results of the previous one (sixth frame) and the second previous (fifth frame) are the same and R_FLG = 0 (step 17). The process proceeds to the next frame (eighth frame) described below.

(H) When video of 8th frame is input (a) Write control Measurement of video information of input video (8th frame) is started (step 02). The write number BW of the frame memory 16 is (3) +1 and BW = (4) (step 03). The input video is written into the bank (4) of the frame memory 16 (step 04). It is determined that the measurement results of the present (8th frame) and the previous (7th frame) are the same (step 05). It is determined that the measurement results of the previous one (seventh frame) and the second previous (sixth frame) are the same (step 07). Move on to processing of the next frame.

(B) Read Control The read number BR of the frame memory 16 is (1) +1 and BR = (2) (step 12). Since the video of the sixth frame is stored in the bank (2), the display timing of the display 20 is calculated based on the measurement information of the sixth frame (step 13). The sixth frame image is read from the bank (2) of the frame memory 16 (step 14). The sixth frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (8th frame) and the previous (7th frame) are the same (step 05). The measurement results of the previous one (seventh frame) and the second previous (sixth frame) are the same, and it is determined that R_FLG = 0 (step 17). Move on to processing of the next frame.

  By the above operation, as shown in FIG. 5C, the disturbance of the display image on the display 20 can be suppressed. Also, the input video (fourth frame) immediately after the input video is switched can be displayed on the display 20 without being lost.

<< Operation example 2 >>
Next, an operation example 2 will be described with reference to FIGS. 3, 4, and 6. FIG. 6A shows a case where a video B disturbed when switching from the input video A to D is present. Similar to the operation example 1, FIG. 6B shows an image of each bank of the frame memory, and FIG. 6C shows a display image of the display 20.

  The operation of the display 20 after the power is turned on (step 01) is as follows.

(A) When video of first frame is input (a) Write control Measurement of video information of input video (first frame) is started (step 02). Since this is the first frame, the write number BW = (1) in the frame memory 16 is obtained (step 03). The input video is written into the bank (1) of the frame memory 16 (step 04). Since it is the first frame, it is determined that there is no previous measurement result (step 05). Since it is the first frame, it is determined that there is no measurement result to be compared (step 07). The process proceeds to the next frame (second frame) below.

(B) Read control At the time when the input of the first frame of video is started, since the video of two frames or more is not yet stored in the frame memory 16, the read control is not executed (step 11).

(B) When video of second frame is input (a) Write control Measurement of video information of input video (second frame) is started (step 02). The write number BW of the frame memory 16 is (1) +1 and BW = (2) (step 03). The input video is written into the bank (2) of the frame memory 16 (step 04). It is determined that the measurement results of the present (second frame) and the previous one (first frame) are the same (step 05). Since it is the second frame, it is determined that there is no measurement result to be compared (step 07). The process proceeds to the following next frame (third frame).

(B) Read Control At the time when the input of the second frame video is started, the video is not stored in the frame memory 16 yet, so the read control is not executed (step 11).

(C) When video of third frame is input (a) Write control Measurement of video information of input video (third frame) is started (step 02). The write number BW of the frame memory 16 is (2) +1 and BW = (3) (step 03). The input video is written into the bank (3) of the frame memory 16 (step 04). It is determined that the measurement results of the present (third frame) and the previous (second frame) are the same (step 05). It is determined that the measurement results of the previous one (second frame) and the second previous (first frame) are the same (step 07). The process proceeds to the following next frame (fourth frame).

(B) Read control Since this is the first read, the read number BR of the frame memory 16 becomes (1) (step 12). The display timing of the display 20 is calculated based on the measurement result of the first frame (step 13). The first frame image is read from the bank (1) of the frame memory 16 (step 14). The first frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (third frame) and the previous (second frame) are the same (step 05). It is determined that the measurement results of the previous frame (second frame) and the previous frame (first frame) are the same and R_FLG = 0 (step 17). The process proceeds to the following next frame (fourth frame).

(D) When the fourth frame video is input (a) Write control Measurement of video information of the input video (fourth frame) is started (step 02). The write number BW of the frame memory 16 is (3) +1 and BW = (4) (step 03). The input video is written into the bank (4) of the frame memory 16 (step 04). It is determined that the measurement results of the present (fourth frame) and the previous one (third frame) are different (step 05). Since the number of mismatches is one, the write number BW of the frame memory 16 is directly BW = (4) (step 06). The process proceeds to the following next frame (fifth frame).

(B) Read Control The read number BR of the frame memory 16 is (1) +1 and BR = (2) (step 12). The display timing of the display 20 is calculated based on the measurement result of the second frame (step 13). Since the second frame has the same measurement result as the first frame, the display timing of the first frame may be used without calculation. The video of the second frame is read from the bank (2) of the frame memory 16 (step 14). The second frame image is displayed on the display 20 (step 15). It is determined that the current (fourth frame) and the previous (third frame) measurement results are different (step 05). Since the number of mismatches is one, the read number BR of the frame memory 16 remains as it is BR = (2), and R_FLG = 0 remains (step 16). The process proceeds to the following next frame (fifth frame).

(E) When video of the fifth frame is input (a) Write control Measurement of video information of the input video (fifth frame) is started (step 02). The write number BW of the frame memory 16 returns to (1) when 1 is added to (4), so BW = (1) (step 03). The input video is written into the bank (1) of the frame memory 16 (step 04). It is determined that the measurement results of the present (5th frame) and the previous (4th frame) are different (step 05). Since the number of mismatches is two, the write number BW of the frame memory 16 is (1) -2 and BW = (3) (step 06). The process proceeds to the following next frame (sixth frame).

(B) Read Control The read number BR of the frame memory 16 is (2) +1 and BR = (3) (step 12). The display timing of the display 20 is calculated based on the measurement result of the third frame (step 13). The video of the third frame is read from the bank (3) of the frame memory 16 (step 14). The third frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (5th frame) and the previous (4th frame) are different (step 05). Since the number of mismatches is two, the read number BR of the frame memory 16 is (3) -1 and BR = (2), and R_FLG = 0 remains (step 16). The process proceeds to the following next frame (sixth frame).

(F) When video of 6th frame is input (a) Write control Measurement of video information of input video (6th frame) is started (step 02). The write number BW of the frame memory 16 is (3) +1 and BW = (4) (step 03). The input video is written into the bank (4) of the frame memory 16 (step 04). With these operations, while the input video does not match the video information of the previous video, the video is overwritten alternately on the banks (4) and (1) of the frame memory 16. Therefore, it is possible to hold the video (third frame) immediately before the mismatch stored in the bank (3). It is determined that the measurement results of the present (sixth frame) and the previous one (fifth frame) are the same (step 05). It is determined that the measurement results of the previous one (fifth frame) and the second previous (fourth frame) are different (step 07). Since the number of mismatches up to the previous video is two, the write number BW of the frame memory 16 is (4) +1 and BW = (1) (step 08). The process proceeds to the following next frame (seventh frame).

(B) Read Control The read number BR of the frame memory 16 is (2) +1 and BR = (3) (step 12). The display timing of the display 20 is calculated based on the measurement result of the third frame (step 13). The video of the third frame is read from the bank (3) of the frame memory 16 (step 14). The third frame image is displayed on the display 20 (step 15). By these operations, while the video information of the input video and the previous video does not match, the video (third frame) immediately before the mismatch is continuously displayed on the display 20. It is determined that the measurement results of the present (sixth frame) and the previous one (fifth frame) are the same (step 05). The measurement results of the previous one (fifth frame) and the second previous (fourth frame) are different, and R_FLG = 0 is determined (step 17). Since the number of mismatches up to the previous video is two, the read number BR of the frame memory 16 is (3) +1, BR = (4), and R_FLG is set to 1 (step 18). The process proceeds to the following next frame (seventh frame).

(G) When video of seventh frame is input (a) Write control Measurement of video information of input video (seventh frame) is started (step 02). The write number BW of the frame memory 16 is (1) +1 and BW = (2) (step 03). The input video is written into the bank (2) of the frame memory 16 (step 04). By these operations, it is possible to prevent the input video (seventh frame) from being overwritten on the bank (1) in which the normal video (fifth frame) not yet displayed on the display 20 is stored. . It is determined that the measurement results of the present (seventh frame) and the previous one (sixth frame) are the same (step 05). It is determined that the measurement results of the previous one (sixth frame) and the second previous (fifth frame) are the same (step 07). The process proceeds to the next frame (eighth frame) described below.

(B) Read Control The read number BR of the frame memory 16 is (4) +1 and BR = (1) (step 12). Since the image of the fifth frame is stored in the bank (1), the display timing of the display 20 is calculated based on the measurement result of the fifth frame (step 13). The fifth frame image is read from the bank (1) of the frame memory 16 (step 14). The fifth frame image is displayed on the display 20 (step 15). With these operations, when the input video and the previous video match, the state is returned from the state where the previous video that has been mismatched is repeatedly displayed on the display 20 to the state where a new video is displayed. It is determined that the measurement results of the present (seventh frame) and the previous one (sixth frame) are the same (step 05). The measurement results of the previous one (sixth frame) and the previous two (fifth frame) are the same, and R_FLG = 1 is determined (step 17). Since R_FLG is 1, the read number BR of the frame memory 16 is (1) -2, BR = (3), and R_FLG is 2 (step 18). The process proceeds to the next frame (eighth frame) described below.

(H) When video of 8th frame is input (a) Write control Measurement of video information of input video (8th frame) is started (step 02). The write number BW of the frame memory 16 is (2) +1 and BW = (3) (step 03). The input video is written into the bank (3) of the frame memory 16 (step 04). It is determined that the measurement results of the present (8th frame) and the previous (7th frame) are the same (step 05). It is determined that the measurement results of the previous one (seventh frame) and the second previous (sixth frame) are the same (step 07). The process proceeds to the following next frame (9th frame).

(B) Read Control The read number BR of the frame memory 16 is (3) +1 and BR = (4) (step 12). Since the video of the sixth frame is stored in the bank (4), the display timing of the display 20 is calculated based on the measurement information of the sixth frame (step 13). The video of the sixth frame is read from the bank (4) of the frame memory 16 (step 14). The sixth frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (8th frame) and the previous (7th frame) are the same (step 05). The measurement results of the previous one (seventh frame) and the second previous (sixth frame) are the same, and R_FLG = 2 is determined (step 17). Since R_FLG is 2, the read number BR of the frame memory 16 is (4) +1 and BR = (1), and R_FLG is returned to 0 (step 18). The process proceeds to the following next frame (9th frame).

(H) When the 9th frame video is input (a) Write control Measurement of video information of the input video (9th frame) is started (step 02). The write number BW of the frame memory 16 is (3) +1 and BW = (4) (step 03). The input video is written into the bank (4) of the frame memory 16 (step 04). It is determined that the measurement results of the present (9th frame) and the previous (eighth frame) are the same (step 05). It is determined that the measurement results of the previous one (8th frame) and the second previous (7th frame) are the same (step 07). Move on to processing of the next frame.

(B) Read Control The read number BR of the frame memory 16 is (1) +1 and BR = (2) (step 12). Since the video of the seventh frame is stored in the bank (2), the display timing of the display 20 is calculated based on the measurement information of the seventh frame (step 13). The video of the seventh frame is read from the bank (2) of the frame memory 16 (step 14). The seventh frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (9th frame) and the previous (eighth frame) are the same (step 05). It is determined that the measurement results of the previous one (8th frame) and the second previous (7th frame) are the same, and R_FLG = 0 (step 17). Move on to processing of the next frame.

  By the above operation, as shown in FIG. 6C, the disturbance of the display image on the display 20 can be suppressed. Also, a normal input video (fifth frame) immediately after the input video is switched can be displayed on the display 20 without being lost.

<< Operation example 3 >>
Finally, an operation example 3 will be described with reference to FIGS. 3, 4, and 7. FIG. 7A shows a case where there are images B and C disturbed when switching from the input image A to D. Similar to the operation examples 1 and 2, FIG. 7B shows an image of each bank of the frame memory, and FIG. 7C shows a display image of the display 20.

  The operation of the display 20 after the power is turned on (step 01) is as follows.

(A) When video of first frame is input (a) Write control Measurement of video information of input video (first frame) is started (step 02). Since this is the first frame, the write number BW = (1) in the frame memory 16 is obtained (step 03). The input video is written into the bank (1) of the frame memory 16 (step 04). Since it is the first frame, it is determined that there is no previous measurement result (step 05). Since it is the first frame, it is determined that there is no measurement result to be compared (step 07). The process proceeds to the next frame (second frame) below.

(B) Read control At the time when the input of the first frame of video is started, since the video of two frames or more is not yet stored in the frame memory 16, the read control is not executed (step 11).

(B) When video of second frame is input (a) Write control Measurement of video information of input video (second frame) is started (step 02). The write number BW of the frame memory 16 is (1) +1 and BW = (2) (step 03). The input video is written into the bank (2) of the frame memory 16 (step 04). It is determined that the measurement results of the present (second frame) and the previous one (first frame) are the same (step 05). Since it is the second frame, it is determined that there is no measurement result to be compared (step 07). The process proceeds to the following next frame (third frame).

(B) Read Control At the time when the input of the second frame video is started, the video is not stored in the frame memory 16 yet, so the read control is not executed (step 11).

(C) When video of third frame is input (a) Write control Measurement of video information of input video (third frame) is started (step 02). The write number BW of the frame memory 16 is (2) +1 and BW = (3) (step 03). The input video is written into the bank (3) of the frame memory 16 (step 04). It is determined that the measurement results of the present (third frame) and the previous (second frame) are the same (step 05). It is determined that the measurement results of the previous one (second frame) and the second previous (first frame) are the same (step 07). The process proceeds to the following next frame (fourth frame).

(B) Read control Since this is the first read, the read number BR of the frame memory 16 becomes (1) (step 12). The display timing of the display 20 is calculated based on the measurement result of the first frame (step 13). The first frame image is read from the bank (1) of the frame memory 16 (step 14). The first frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (third frame) and the previous (second frame) are the same (step 05). It is determined that the measurement results of the previous frame (second frame) and the previous frame (first frame) are the same and R_FLG = 0 (step 17). The process proceeds to the following next frame (fourth frame).

(D) When the fourth frame video is input (a) Write control Measurement of video information of the input video (fourth frame) is started (step 02). The write number BW of the frame memory 16 is (3) +1 and BW = (4) (step 03). The input video is written into the bank (4) of the frame memory 16 (step 04). It is determined that the measurement results of the present (fourth frame) and the previous one (third frame) are different (step 05). Since the number of mismatches is one, the write number BW of the frame memory 16 is directly BW = (4) (step 06). The process proceeds to the following next frame (fifth frame).

(B) Read Control The read number BR of the frame memory 16 is (1) +1 and BR = (2) (step 12). The display timing of the display 20 is calculated based on the measurement result of the second frame (step 13). Since the second frame has the same measurement result as the first frame, the display timing of the first frame may be used without calculation. The video of the second frame is read from the bank (2) of the frame memory 16 (step 14). The second frame image is displayed on the display 20 (step 15). It is determined that the current (fourth frame) and the previous (third frame) measurement results are different (step 05). Since the number of mismatches is one, the read number BR of the frame memory 16 remains as it is BR = (2), and R_FLG = 0 remains (step 16). The process proceeds to the following next frame (fifth frame).

(E) When video of the fifth frame is input (a) Write control Measurement of video information of the input video (fifth frame) is started (step 02). The write number BW of the frame memory 16 returns to (1) when 1 is added to (4), so BW = (1) (step 03). The input video is written into the bank (1) of the frame memory 16 (step 04). It is determined that the measurement results of the present (5th frame) and the previous (4th frame) are different (step 05). Since the number of mismatches is two, the write number BW of the frame memory 16 is (1) -2 and BW = (3) (step 06). The process proceeds to the following next frame (sixth frame).

(B) Read Control The read number BR of the frame memory 16 is (2) +1 and BR = (3) (step 12). The display timing of the display 20 is calculated based on the measurement result of the third frame (step 13). The video of the third frame is read from the bank (3) of the frame memory 16 (step 14). The third frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (5th frame) and the previous (4th frame) are different (step 05). Since the number of mismatches is two, the read number BR of the frame memory 16 is (3) -1 and BR = (2), and R_FLG = 0 remains (step 16). The process proceeds to the following next frame (sixth frame).

(F) When video of 6th frame is input (a) Write control Measurement of video information of input video (6th frame) is started (step 02). The write number BW of the frame memory 16 is (3) +1 and BW = (4) (step 03). The input video is written into the bank (4) of the frame memory 16 (step 04). With these operations, while the input video does not match the video information of the previous video, the video is overwritten alternately on the banks (4) and (1) of the frame memory 16. Therefore, it is possible to hold the video (third frame) immediately before the mismatch stored in the bank (3). It is determined that the measurement result of the present (sixth frame) and the previous one (fifth frame) are different (step 05). Since the number of mismatches is 3, the write number BW of the frame memory 16 is BW = (4) as it is (step 06). The process proceeds to the following next frame (seventh frame).

(B) Read Control The read number BR of the frame memory 16 is (2) +1 and BR = (3) (step 12). The display timing of the display 20 is calculated based on the measurement result of the third frame (step 13). The video of the third frame is read from the bank (3) of the frame memory 16 (step 14). The third frame image is displayed on the display 20 (step 15). By these operations, while the video information of the input video and the previous video does not match, the video (third frame) immediately before the mismatch is continuously displayed on the display 20. It is determined that the measurement result of the present (sixth frame) and the previous one (fifth frame) are different (step 05). Since the number of mismatches is 3, the read number BR of the frame memory 16 is (3) -1 and BR = (2), and R_FLG = 0 is maintained (step 16). The process proceeds to the following next frame (seventh frame).

(G) When video of seventh frame is input (a) Write control Measurement of video information of input video (seventh frame) is started (step 02). The write number BW of the frame memory 16 returns to (1) when 1 is added to (4), so BW = (1) (step 03). The input video is written into the bank (1) of the frame memory 16 (step 04). It is determined that the measurement results of the present (seventh frame) and the previous one (sixth frame) are the same (step 05). It is determined that the measurement results of the previous one (sixth frame) and the second previous (fifth frame) are different (step 07). Since the number of mismatches up to the previous video is three, the write number BW of the frame memory 16 is (1) as it is (step 08). The process proceeds to the next frame (eighth frame) described below.

(B) Read Control The read number BR of the frame memory 16 is (2) +1 and BR = (3) (step 12). The display timing of the display 20 is calculated based on the measurement result of the third frame (step 13). The video of the third frame is read from the bank (3) of the frame memory 16 (step 14). The third frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (seventh frame) and the previous one (sixth frame) are the same (step 05). It is determined that the measurement results of the previous one (sixth frame) and the second previous (fifth frame) are different (step 17). Since the number of mismatches of the measurement results up to the previous video (sixth frame) is 3, the read number BR of the frame memory 16 remains as BR = (3), and R_FLG = 0 remains (step) .18). The process proceeds to the next frame (eighth frame) described below.

(H) When video of 8th frame is input (a) Write control Measurement of video information of input video (8th frame) is started (step 02). The write number BW of the frame memory 16 is (1) +1 and BW = (2) (step 03). The input video is written into the bank (2) of the frame memory 16 (step 04). It is determined that the measurement results of the present (8th frame) and the previous (7th frame) are the same (step 05). It is determined that the measurement results of the previous one (seventh frame) and the second previous (sixth frame) are the same (step 07). The process proceeds to the following next frame (9th frame).

(B) Read Control The read number BR of the frame memory 16 is (3) +1 and BR = (4) (step 12). Since the video of the sixth frame is stored in the bank (4), the display timing of the display 20 is calculated based on the measurement information of the sixth frame (step 13). The video of the sixth frame is read from the bank (4) of the frame memory 16 (step 14). The sixth frame image is displayed on the display 20 (step 15). With these operations, when the input video and the previous video match, the state is returned from the state where the previous video that has been mismatched is repeatedly displayed on the display 20 to the state where a new video is displayed. It is determined that the measurement results of the present (8th frame) and the previous (7th frame) are the same (step 05). The measurement results of the previous one (seventh frame) and the second previous (sixth frame) are the same, and it is determined that R_FLG = 0 (step 17). The process proceeds to the following next frame (9th frame).

(H) When the 9th frame video is input (a) Write control Measurement of video information of the input video (9th frame) is started (step 02). The write number BW of the frame memory 16 is (2) +1 and BW = (3) (step 03). The input video is written into the bank (3) of the frame memory 16 (step 04). It is determined that the measurement results of the present (9th frame) and the previous (eighth frame) are the same (step 05). It is determined that the measurement results of the previous one (8th frame) and the second previous (7th frame) are the same (step 07). Move on to processing of the next frame.

(B) Read Control The read number BR of the frame memory 16 is (4) +1 and BR = (1) (step 12). Since the image of the seventh frame is stored in the bank (1), the display timing of the display 20 is calculated based on the measurement information of the seventh frame (step 13). The video of the seventh frame is read from the bank (1) of the frame memory 16 (step 14). The seventh frame image is displayed on the display 20 (step 15). It is determined that the measurement results of the present (9th frame) and the previous (eighth frame) are the same (step 05). It is determined that the measurement results of the previous one (8th frame) and the second previous (7th frame) are the same, and R_FLG = 0 (step 17). Move on to processing of the next frame.

  By the above operation, as shown in FIG. 7C, the disturbance of the display image on the display 20 can be suppressed. Also, a normal input video (sixth frame) immediately after the input video is switched can be displayed on the display 20 without being lost.

  As described above, in the video display device according to the embodiment of the present invention, when the measurement result of the input video does not match the previous measurement result, the input video A immediately before the mismatch is displayed on the display 20. . Thereby, the disturbed images B and C in the middle of switching when switching from the input image A to D are not displayed on the display 20, so that the disturbance of the display image on the display 20 can be suppressed.

  In addition, after the switching of the input video is completed, video information for two frames or more is necessary for the video to be switched and to be in a stable state. Therefore, in the video display device according to the embodiment of the present invention, when the measurement result of the input video does not match the previous measurement result, the input video immediately before the mismatch is not stored in the memory area in the frame memory 16. Input video is alternately written (overwritten) in a plurality of memory areas, for example, banks (4) and (1). Thereby, after the input video is switched, it is possible to display on the display 20 without losing the normal video immediately after the switching.

  That is, in the example of FIG. 7, the video A of the first to third frames and the video D of the sixth to ninth frames are normal videos. The images B and C in the fourth to fifth frames are images that are disturbed during switching. The normal video immediately after switching is the video D in the sixth frame. In this case, as shown in FIG. 7C, the normal image D of the sixth frame can be displayed on the display 20 without being lost.

  Further, until the calculation for properly displaying the input video D after switching is completed, the input video A before switching is continuously displayed on the display 20, and when the calculation is completed, the input video D after switching is displayed. 20 is displayed. Thereby, the input video D after switching can be displayed on the display 20 at an appropriate timing.

  In the operation examples 1, 2, and 3, the case where there are 0 frames, 1 frame, and 2 frames of distorted video has been described, but the same applies when there are 3 or more frames. That is, when the number of frames of the disturbed video is an odd number, the operation is the same as that of the operation example 2 (FIG. 6) in the case where one frame of the disturbed video exists. Further, when the number of frames of the disturbed video is an even number, the operation is the same as that of the operation example 3 (FIG. 7) in the case where there are two frames of the disturbed video. Therefore, even when there are three or more frames of distorted video, it is possible to suppress the distorted video displayed on the display 20.

  Also, step. Of the flowchart shown in FIG. 05, step. 07, step. Of the flowchart shown in FIG. In 217, the video information of two frames is compared to determine whether or not the video information is the same, but the present invention is not limited to this. That is, three or more frames of video information may be compared to determine whether all the video information is the same. However, when comparing video information of three or more frames, since the determination of whether the video information is the same is delayed by the number of added frames, the number of banks of the frame memory 16 is increased by the number of added frames. increase. That is, when comparing video information (measurement results) for N frames, the number of banks in the frame memory 16 is set to N + 2. In this case, the basic idea is the same. The write number BW and the read number BR are in the order of (1) → (2) → (3) → (4) →... → (N) → (N + 1) → (N + 2) → (1) →. Just increment it.

  In addition, the present invention can be realized not only as a video display device, but also as a video display method that uses a characteristic processing unit included in such a video display device as a step, or executes these steps in a computer. It can also be realized as a program to be executed. It goes without saying that such a program can be distributed via a recording medium such as a CD-ROM or a transmission medium such as the Internet.

DESCRIPTION OF SYMBOLS 11 ... Video information measurement part 12 ... Video information storage part 13 ... Video information comparison part 14 ... Write number determination part 15 ... Write control part 16 ... Frame memory 17 ... Read number determination part 18 ... Read control part 19 ... Display timing derivation part 20 ... Display (display part)
(1) to (4) ... Bank BW ... Write number BR ... Read number

Claims (7)

A video information measuring unit that measures video information including at least one of a horizontal / vertical synchronization signal, a clock signal cycle, a position of a data enable signal, and size , which is information of each frame of the input video;
A frame memory for storing the input video;
A video information comparison unit that compares the measurement result of the video information measurement unit with the previous measurement result;
Write control for alternately writing the input video to a plurality of memory areas in which the input video immediately before the mismatch is not stored among the memory areas in the frame memory when the comparison result of the video information comparison unit does not match And
When the comparison result of the video information comparison unit does not match, a read control unit that reads the input video immediately before the mismatch from the frame memory,
A display unit for displaying the input video read by the read control unit,
When the comparison result of the video information comparison unit does not match, the write control unit does not store the input video immediately before the mismatch in the memory area in the frame memory depending on whether the number of mismatches is an even number or not. Control the order of writing the input video to a plurality of memory areas,
When the comparison result of the video information comparison unit does not match, the read control unit receives the input video from the frame memory according to whether the number of mismatches is 1 or 2 or more, and whether the number of mismatches is even or odd. By controlling the reading order,
While the comparison result of the video information comparison unit does not match, the display unit continues to display the input video immediately before the mismatch, and after the comparison result of the video information comparison unit matches, the oldest input that matches An image display device that sequentially displays input images without losing images .   The display unit continues to display the input video before switching until the calculation for appropriately displaying the input video after switching is completed, and displays the input video after the switching when the calculation is completed. The video display device according to claim 1. A write number determination unit that determines a write number of the frame memory using a comparison result of the video information comparison unit, the number of mismatches of the video information, and a write number of one frame before;
The video display device according to claim 2, wherein the write control unit writes the input video to a write number determined by the write number determination unit. The readout number for determining the readout number of the frame memory using the comparison result of the video information comparison section, the number of mismatches of the video information, the information flag when the previous readout number is determined, and the readout number one frame before With a decision unit,
The video display device according to claim 2, wherein the read control unit reads the input video from a read number determined by the read number determination unit.   5. The video display device according to claim 1, wherein the frame memory has a memory area capable of storing the input video for four frames. 6.   6. The video display device according to claim 5, wherein, when the measurement results are compared for N frames, the frame memory has a memory area capable of storing the input video for N + 2 frames. . A video information measuring step for measuring video information which is information of each frame of the input video, and includes at least one of a horizontal / vertical synchronizing signal, a clock signal period, a position and a size of a data enable signal;
A video information comparison step for comparing the measurement result of the video information measurement step with the previous measurement result;
If the comparison result of the video information comparison step does not match, among the memory areas in the frame memory for storing the input video, alternately to a plurality of memory areas in which the input video immediately before the mismatch is not stored A writing control step of writing the input video;
If the comparison result of the video information comparison step does not match, the read control step of reading the input video immediately before the mismatch from the frame memory,
A display step for displaying the input video read by the read control step,
In the write control step, if the comparison result of the video information comparison step is mismatched, the input video immediately before the mismatch is not stored in the memory area in the frame memory depending on whether the number of mismatches is an even number. Control the order of writing the input video to a plurality of memory areas,
In the reading control step, if the comparison result of the video information comparison step is mismatched, the number of mismatches is one or two or more, and the number of mismatches is even or odd, and the input video is read from the frame memory. By controlling the reading order,
During the display step, while the comparison result of the video information comparison step does not match, the input video immediately before the mismatch is displayed, and after the comparison result of the video information comparison step matches, the oldest input that matches An image display method characterized by sequentially displaying input images without losing images .

Images