JP4448414B2 - Video display device and video display method - Google Patents

Description

  The present invention relates to a video display device and a video display method, and more particularly to a video display device and a video display method suitable for performing RGB conversion on a digital video signal transmitted in synchronization with a synchronization signal.

  2. Description of the Related Art In recent years, in-vehicle navigation devices have been equipped with a television tuner so that television broadcast images received by the television tuner can be displayed on a display screen of a video display device.

  FIG. 6 shows an example of such a video display device 1, and this video display device 1 has a television tuner 2, and this television tuner 2 is controlled by channel control by the microcomputer 3. TV video signals are received.

  The TV tuner 2 outputs the received TV video signal as an analog NTSC signal which is an analog video signal.

  A video decoder IC 4 is connected to the output side of the TV tuner 2, and the video decoder IC 4 inputs an analog NTSC signal output from the TV tuner 2.

  The video decoder IC4 encodes the input analog video signal and outputs it as a digital YUV signal which is a digital video signal.

  A graphic LSI 5 is connected to the output side of the video decoder IC 4, and the graphic LSI 5 receives the digital YUV signal output from the video decoder IC 4.

  The graphic LSI 5 outputs the input digital YUV signal after appropriately processing it.

  The digital YUV signal output from the graphic LSI 5 is decoded by a D / A (digital / analog converter) 6, is then subjected to RGB conversion by an RGB conversion element 7, and finally displayed on the liquid crystal display unit 8. It has become.

  Note that the order of the D / A 6 and the RGB conversion element 7 may be reversed, and may be built in the graphic LSI 5.

  Here, as shown in FIG. 7, the content of the digital video signal transferred by the video decoder IC4 or the like is obtained by multiplexing the C signal that is a color signal and the Y signal that is a luminance signal. The signal and the Y signal are transferred so as to be synchronized with a horizontal direction synchronization signal and a vertical direction synchronization signal (not shown) shown in FIG.

  In addition, the data transfer format is, for example, when transferring only the data for the effective video period that is actually displayed or when transferring the data for the blanking period that is not actually displayed. There were various.

  Among them, when data in the blanking period is also transferred, it is synchronized with the horizontal direction synchronizing signal and the vertical direction synchronizing signal in the horizontal horizontal blanking period and vertical vertical blanking period shown in FIG. 8, respectively. In this way, a digital video signal corresponding to black is transferred. As shown in FIG. 9, the digital video signal corresponding to black has a different value between the C signal and the Y signal, depending on the conversion formula used. In FIG. 9, the C signal has a value having no color (80h), and the Y signal has a value having no luminance (10h).

  Here, the data in the blanking period is normally not displayed because it is outside the display range, that is, outside the effective video area, and the receiving side recognizes the blanking period and discards or replaces the data. .

  However, in a television signal or the like, an unusual state may occur due to the influence of a weak electric field or the like.

  When such a situation occurs, the blanking period of the video is displayed in the effective video area within the effective video period because the synchronization signal sent in addition to the video data fluctuates due to fluctuations from the normal period and frequency. May end up. That is, as shown in FIG. 10, when the horizontal direction synchronization signal is disturbed, the horizontal blanking period is displayed for each line, and when the vertical direction synchronization signal is disturbed, several lines are displayed together. Will be.

  Therefore, as described above, if a digital video signal corresponding to black is transferred to the blanking period, the video is disturbed by the influence of a weak electric field or the like, and even if black in the blanking period is displayed within the effective video period. There is no sense of incongruity, and in particular, there is no problem at all in the state where the color is cut off.

JP 2000-125150 A

  However, when the synchronization signal is disturbed and the frequency is high, depending on the circuit configuration on the receiver side of the video data, the order of the multiplexed C signal and Y signal may be misidentified, the C signal as the Y signal, and the Y signal as the C signal. May be displayed.

  For example, as shown in FIG. 11, in the blanking period, when the C signal and the Y signal in the digital video signal corresponding to black are interchanged with each other, green is displayed.

  Usually, such switching between the C signal and the Y signal occurs in line units, and when it is displayed, as shown in FIG. 12, a chromatic color (such as green) in the horizontal direction within the effective video area ( The line with the mesh part in the drawing) is displayed so as to fly.

  When such a chromatic line is displayed when there is no failure such as when a weak electric field is generated, it becomes very conspicuous compared with black, giving an impression of failure or the like.

  Therefore, the present invention has been made in view of the above points, and even when the video of the blanking period is displayed within the effective video period due to the disturbance of the synchronization signal, the video of the blanking period is not conspicuous. It is an object of the present invention to provide a video display device and a video display method that can display in color, and that can improve display quality.

In order to achieve the above-described object, the video display device according to the present invention is characterized in that a digital video signal composed of a color signal and a luminance signal is converted into a horizontal synchronization signal and a vertical synchronization signal in both an effective video period and a blanking period. A video display device including a transfer device that transfers the signal in synchronization with the signal, and capable of performing RGB conversion on the digital video signal transferred from the transfer device and displaying the color signal in a blanking period; And the luminance signal are transferred as values corresponding to gray . At that time, the value of the color signal is set as a reference value having no color as a value corresponding to gray, and the luminance signal is set as a value corresponding to gray. The transfer is performed with the same value as the reference value .

And according to such a structure, it becomes possible to make the color of the image | video of a blanking period gray by a transfer apparatus. Further, even if the luminance signal and the color signal corresponding to gray are set to the same value, even if the luminance signal and the color signal are mistakenly interchanged, the color displayed by the replacement is initially set. It becomes possible to make the same gray.

  Further, the video display device according to the present invention is characterized in that the color signal and the luminance signal in the blanking period when the transfer device has a disturbance in at least one of the horizontal direction synchronization signal and the vertical direction synchronization signal exceeding an allowable value. Is set to a value corresponding to gray, and when the disturbance is less than an allowable value, the color signal and the luminance signal in the blanking period are set to values corresponding to black.

  Then, according to such a configuration, if the disturbance of the synchronization signal is only a level that does not cause misconception of the order of the color signal and the luminance signal, even if the video of the blanking period is displayed, The video can be displayed in black. On the other hand, when the disturbance of the synchronization signal is so great that the order of the luminance signal and the color signal is misidentified, the color of the video in the blanking period can be changed to gray.

Furthermore, the video display method according to the present invention is characterized in that a digital video signal composed of a color signal and a luminance signal is synchronized with a horizontal direction synchronization signal and a vertical direction synchronization signal in both an effective video period and a blanking period. In the video display method in which the transferred digital video signal is converted to RGB and displayed, the color signal and the luminance signal in the blanking period are transferred as values corresponding to gray, and at that time, the color The signal value is a reference value having no color as a value corresponding to gray, and the luminance signal is transferred with the same value as the reference value as a value corresponding to gray .

And according to such a method, it becomes possible to make the color of the image | video of a blanking period gray. Further, even if the luminance signal and the color signal corresponding to gray are set to the same value, even if the luminance signal and the color signal are mistakenly interchanged, the color displayed by the replacement is initially set. It becomes possible to make the same gray.

  Furthermore, the video display method according to the present invention is characterized in that the color signal and the luminance signal in the blanking period are gray when at least one disturbance of the horizontal direction synchronization signal and the vertical direction synchronization signal exceeds an allowable value. When the disturbance is less than the allowable value, the color signal and the luminance signal in the blanking period are set to values corresponding to black.

  And according to such a method, even if the image of the blanking period is displayed when the disturbance of the synchronization signal is only a level that does not cause misrecognition of the order of the color signal and the luminance signal, The video can be displayed in black. On the other hand, when the disturbance of the synchronization signal is so great that the order of the luminance signal and the color signal is misidentified, the color of the video in the blanking period can be changed to gray.

  According to the video display device of the present invention, the image of the blanking period can be made gray by the transfer device, and as a result, the video of the blanking period is displayed within the effective video period due to the disturbance of the synchronization signal. However, it is possible to display the video during the blanking period in an inconspicuous color, thereby improving the display quality.

  Further, according to the video display device of the present invention, it is assumed that the luminance signal and the color signal corresponding to gray are misidentified so that the luminance signal and the color signal are interchanged with each other because they have the same value. However, as a result of changing the color displayed by the replacement to the same gray as the original, the video in the blanking period displayed within the effective video period due to the disturbance of the synchronization signal can be made inconspicuous.

  Furthermore, according to the video display device according to the present invention, when the disturbance of the synchronization signal is only a level that does not cause misrecognition of the order of the color signal and the luminance signal, the video of the blanking period is displayed. However, when the video can be displayed in black, and the disturbance of the sync signal is so large that the order of the luminance signal and the color signal is misidentified, the color of the video during the blanking period is changed to gray. As a result, the video in the blanking period displayed within the effective video period due to the disturbance of the synchronization signal can be made less noticeable.

  Furthermore, according to the video display method of the present invention, as a result of the color of the video in the blanking period being gray, the video in the blanking period is displayed within the effective video period due to the disturbance of the synchronization signal. However, the image during the blanking period can be displayed in an inconspicuous color, and as a result, the display quality can be improved.

  According to the video display method of the present invention, it is assumed that the luminance signal and the color signal corresponding to gray are misidentified so that the luminance signal and the color signal are interchanged with each other because they have the same value. However, as a result of changing the color displayed by the replacement to the same gray as the original, the video in the blanking period displayed within the effective video period due to the disturbance of the synchronization signal can be made inconspicuous.

  Furthermore, according to the video display method according to the present invention, when the disturbance of the synchronization signal is only a level that does not cause misrecognition of the order of the color signal and the luminance signal, the video during the blanking period is displayed. However, when the video can be displayed in black, and the disturbance of the sync signal is so large that the order of the luminance signal and the color signal is misidentified, the color of the video during the blanking period is changed to gray. As a result, the video in the blanking period displayed within the effective video period due to the disturbance of the synchronization signal can be made less noticeable.

  Hereinafter, embodiments of a video display device according to the present invention will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the video display apparatus 10 according to the present embodiment includes a television tuner 2. The television tuner 2 is synchronized with a horizontal direction synchronization signal and a vertical direction synchronization signal, for example, a composite. -Analog video signals such as video signals and analog RGB signals are output. Furthermore, the television tuner 2 outputs the received electric field strength.

  A video processing / sync separation unit 11 is connected to the output side of the TV tuner 2, and an analog video signal and a synchronization signal output from the TV tuner 2 are separately output to the video processing / sync separation unit 11. In this case, a synchronization signal is input.

  The video processing / synchronization separation unit 11 converts the input analog video signal into a digital video signal, and performs video processing such as separating the digital video signal, the horizontal synchronization signal, and the vertical synchronization signal from each other. It is like that.

  The video processing / sync separation unit 11 outputs the separated digital video signal, horizontal direction synchronization signal, and vertical direction synchronization signal.

  A blanking period color processing unit 12 as a transfer device is connected to the output side of the video processing / synchronization separation unit 11, and this blanking period color processing unit 12 is output from the video processing / synchronization separation unit 11. A digital video signal, a horizontal direction synchronization signal, and a vertical direction synchronization signal are input.

    As described above, instead of converting the analog video signal into the digital video signal in the video processing / synchronization separation unit 11, the blanking period color processing unit 12 may convert the analog video signal into the digital video signal. Good.

  Here, as shown in FIG. 2, the digital video signal is obtained by multiplexing the C signal and the Y signal. In the present embodiment, the blanking period color processing unit 12 uses the C signal in the blanking period. And Y signal are transferred with values corresponding to gray.

  As a result, even if an image in the blanking period is displayed within the effective image period due to the influence of a weak electric field or the like, the image can be displayed in gray that is not noticeable.

  In this embodiment, the blanking period color processing unit 12 sets the value of the C signal in the blanking period as a reference value having no color in order to set the color of the video in the blanking period to gray. The data is transferred with the same value as the reference value. In FIG. 2, the value of the C signal is set as a reference value 80h, and the value of the Y signal 80h is matched with this reference value.

  As a result, even if the C signal and the Y signal are mistakenly interchanged due to the influence of a weak electric field or the like, the color displayed by the interchange can be the same gray as the original.

  Note that, as shown in FIG. 3, both the video in the horizontal blanking period and the video in the vertical blanking period may be gray. Not limited to this, as shown in FIG. 4, only the video in the horizontal blanking period may be gray and the video in the vertical blanking period may be black. Conversely, only the video in the vertical blanking period may be gray and the video in the vertical blanking period may be black.

  In addition to the above configuration, in the present embodiment, it is possible to determine the disturbance of the horizontal direction synchronization signal and the vertical direction synchronization signal and reflect the determination result in the video during the blanking period.

  That is, returning to FIG. 1, a video input level monitoring unit 14 is connected to the output side of the TV tuner 2, and the video input level monitoring unit 14 outputs video processing / synchronous separation from the TV tuner 2. The same analog video signal as the analog video signal input to the unit 11 is input.

  The video input level monitoring unit 14 monitors the level of the input analog video signal and outputs a monitoring result.

  Further, an input side synchronization signal cycle monitoring unit 15 is connected to the output side of the television tuner 2, and the video processing / synchronization separation unit 11 output from the TV tuner 2 is connected to the input side synchronization signal cycle monitoring unit 15. The same synchronizing signal as the horizontal synchronizing signal and the vertical synchronizing signal input to is input.

  The input-side synchronization signal period monitoring unit 15 monitors the period of the input horizontal direction synchronization signal and vertical direction synchronization signal and outputs a monitoring result.

  Further, an output side synchronization signal cycle monitoring unit 16 is connected to the output side of the video processing / synchronization separation unit 11, and an output from the video processing / synchronization separation unit 11 is output to the output side synchronization signal cycle monitoring unit 16. The same synchronizing signal as the horizontal synchronizing signal and vertical synchronizing signal input to the blanking period color processing unit 12 is input.

  The output-side synchronization signal period monitoring unit 16 monitors the period of the input horizontal direction synchronization signal and the horizontal direction synchronization signal, and outputs a monitoring result.

  Furthermore, a disturbance determination unit 18 is connected to the output side of the TV tuner 2, and the reception electric field strength output from the TV tuner 2 is input to the disturbance determination unit 18.

  Further, the video input level monitoring unit 14, the input side synchronization signal cycle monitoring unit 15, and the output side synchronization signal cycle monitoring unit 16 described above are connected to the input side of the disturbance determination unit 18. The monitoring results output from 15 and 16 are input.

  Based on input information such as the received electric field strength and the monitoring results, the disturbance determination unit 18 has a disturbance in the horizontal direction synchronization signal and the vertical direction synchronization signal that is greater than or equal to an allowable value that causes misrecognition of the C signal and the Y signal. It is determined whether or not there is, and the determination result is output to the blanking period color processing unit 12.

  The disturbance determination unit 18 may perform determination based on all input information, or one of all input information (for example, only the received electric field strength) or a plurality of input information. The determination may be made based on a part of the input information.

  Then, the blanking period color processing unit 12 determines that the C signal and the Y signal in the blanking period when the disturbance of the horizontal direction synchronization signal and the vertical direction synchronization signal is equal to or greater than the allowable value based on the determination result of the disturbance determination unit 18. Is set to a value corresponding to gray.

  On the other hand, when the disturbance is less than the allowable value, the blanking period color processing unit 12 sets the C signal and the Y signal in the blanking period to values corresponding to black.

  As a result, the video in the blanking period is preferably black as long as there is no misidentification between the C signal and the Y signal. If it is less than the allowable value that causes the signal to be misidentified, the image during the blanking period can be made black.

  Although not shown, an RGB conversion element or a liquid crystal display unit for converting the digital video signal output from the blanking period color processing unit 12 into RGB and displaying it on the output side of the blanking period color processing unit 12. Etc. are connected.

  Further, the present invention is not limited to the above-described configuration, and all the images in the blanking period may be displayed in gray regardless of the level of disturbance of the horizontal direction synchronization signal and the vertical direction synchronization signal.

  Next, an embodiment of a video display method according to the present invention will be described with reference to FIG.

  In addition, the video display method in this embodiment is performed using the video display apparatus 10 mentioned above for convenience.

  In this embodiment, after starting the processing for video display, first, in step 1 (ST1) of FIG. 5, control of the video in the blanking period based on the disturbance of the horizontal direction synchronization signal and the vertical direction synchronization signal. Select whether or not to perform.

  In step 1 (ST1), when control is performed based on disturbance of each synchronization signal, the process proceeds to step 2 (ST2). When uniform control is performed without being based on disturbance, step 1 is performed. 6 (ST6).

  In step 2 (ST2), the disturbance determination unit 18 obtains input information from the TV tuner 2, the video input level monitoring unit 14, the input side synchronization signal cycle monitoring unit 15, and the output side synchronization signal cycle monitoring unit 16, thereby obtaining Preparations for determining the disturbance of the horizontal synchronization signal and the vertical synchronization signal are made.

  In subsequent step 3 (ST3), the disturbance determination unit 18 determines whether or not the disturbance of the horizontal direction synchronization signal and the vertical direction synchronization signal is greater than or equal to an allowable value based on all or part of the input information. If the value is equal to or greater than the allowable value, the process proceeds to step 4 (ST4), and if not, the process proceeds to step 5 (ST5).

  In step 4 (ST4), the blanking period color processing unit 12 sets the C signal and Y signal in the blanking period to values corresponding to gray. Specifically, the value of the C signal is set as a reference value having no color, and the value of the Y signal is adjusted to the same value as the reference value.

  As a result, even if the video in the blanking period is displayed within the effective video period, the video can be displayed in inconspicuous gray.

  On the other hand, in step 5 (ST5), the blanking period color processing unit 12 sets the C signal and Y signal in the blanking period to values corresponding to black.

  In step 6 (ST6), it is selected whether or not the video in the blanking period is grayed. If grayed, the process proceeds to step 7 (ST7). If not grayed, the process proceeds to step 8 (ST8). .

  In step 7 (ST7), the C signal and the Y signal in the blanking period are set to values corresponding to gray.

  On the other hand, in step 8 (ST8), the C signal and the Y signal in the blanking period are set to values corresponding to black.

  As described above, according to the present embodiment, as a result of the display in the blanking period being gray, even if the video of the blanking period is displayed within the effective video period due to the disturbance of the synchronization signal, The blanking period video can be displayed in an inconspicuous color, and as a result, the display quality can be improved.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed.

  For example, the color processing of the video during the blanking period can be performed using hardware such as the blanking period color processing unit 12 described above, but is not limited thereto, and a register that can change the digital video signal in software. It is also possible to detect the disturbance state of the synchronization signal and change the color of the blanking period by software setting.

The block diagram which shows embodiment of the video display apparatus which concerns on this invention The figure which shows C signal and Y signal in a blanking period in embodiment of the video display apparatus based on this invention with a horizontal direction synchronizing signal The figure which shows an example of the display state of the image | video of a blanking period in embodiment of the video display apparatus which concerns on this invention. The figure which shows another example different from FIG. 3 of the display state of the image | video of a blanking period in embodiment of the video display apparatus which concerns on this invention. The flowchart which shows embodiment of the video display method which concerns on this invention Block diagram showing an example of a conventional video display device The figure which shows the digital video signal comprised by C signal and Y signal with a horizontal direction synchronizing signal Conceptual diagram showing effective video area and blanking period The figure which shows C signal and Y signal of the blanking period in the conventional video display method The figure which shows an example of the display state of the image | video of a blanking period when the disturbance of the synchronizing signal is not large in the conventional video display method The figure which shows the state recognized by replacing the C signal and Y signal of the blanking period in the conventional video display method The figure which shows the display state of the image | video of the blanking period in the case of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image display apparatus 12 Blanking period color processing part 18 Disturbance judgment part

Claims (4)

A transfer device that transfers a digital video signal composed of a color signal and a luminance signal so as to be synchronized with the horizontal synchronization signal and the vertical synchronization signal in both the effective video period and the blanking period;
In the video display device capable of displaying the digital video signal transferred from the transfer device by RGB conversion,
The transfer device transfers the color signal and the luminance signal in the blanking period as values corresponding to gray, and at that time, the value of the color signal is set as a reference value having no color as a value corresponding to gray, An image display device, wherein the luminance signal is transferred with the same value as the reference value as a value corresponding to gray . The transfer device, when the disturbance of at least one of the horizontal direction synchronization signal and the vertical direction synchronization signal is greater than or equal to an allowable value, the color signal and the luminance signal in the blanking period to a value corresponding to gray, when said disturbances is less than the allowable value, the image display apparatus according to the color and luminance signals in the blanking period to claim 1, characterized in that the value corresponding to black. A digital video signal composed of a color signal and a luminance signal is transferred so as to be synchronized with the horizontal direction synchronizing signal and the vertical direction synchronizing signal in both the effective video period and the blanking period, and this transferred digital video signal is converted to RGB. In the video display method for displaying
The color signal and the luminance signal in the blanking period are transferred as values corresponding to gray . At this time, the value of the color signal is set as a reference value having no color as the value corresponding to gray, and the luminance signal is converted to gray. A video display method characterized by transferring the same value as the reference value as a value corresponding to When the disturbance of at least one of the horizontal direction synchronization signal and the vertical direction synchronization signal exceeds an allowable value, the color signal and the luminance signal in the blanking period are set to values corresponding to gray, and the disturbance is an allowable value. 4. The video display method according to claim 3 , wherein when the value is less than 1, the color signal and the luminance signal in the blanking period are set to values corresponding to black.