JP4726551B2 - Display device - Google Patents

Description

  The present invention relates to a display device such as a digital broadcast receiver.

Broadcast video has a normal 4: 3 or 16: 9 screen size (aspect ratio), which is said to be a wide screen, and the broadcast receiving apparatus displays the received video in a 4: 3 or 16: 9 size display. indicate. Furthermore, the broadcast receiving apparatus is equipped with a size switching function for switching the screen size by a user operation (see Patent Document 1). A screen size determination circuit that automatically determines (format determination) a screen size (aspect ratio) from a video signal is also known (see Patent Document 2).
JP 2003-333455 A Japanese Patent Laid-Open No. 9-247572

  By the way, in digital broadcasting, it is possible to superimpose information (screen size information, aspect ratio information) indicating an aspect ratio on a broadcast wave transmitted by a broadcasting station, and the broadcast receiving apparatus acquires the aspect ratio information separately. Thus, the screen size of the received video can be known, and the video can be displayed in an appropriate size based on the screen size of the received video and the screen size of the display.

  However, if the aspect ratio information is not included in the broadcast wave, video display will not be performed at an appropriate size, and the user is forced to specify the screen size of the display video using the size switching function described above. Will do. Similarly, when aspect ratio information is not included in a video signal input from an external device such as a DVD recorder (player) (the aspect ratio information is not included in a component analog video signal), the user is unavoidable. The screen size of the display image is designated using the size switching function described above. For this reason, although the original video should be displayed at 16: 9, it may be processed into a screen size as if a 4: 3 video has been input. Shaped objects may be displayed vertically or stretched horizontally and displayed in a non-circular shape. Further, when the above-described screen size determination circuit is used, the display device becomes expensive.

  In view of the above circumstances, the present invention can estimate the screen size (format) of an input video without performing complicated processing on the video, and based on this estimation, the input video is suitable for the screen size of the display. It is an object to provide a display device that can be converted into a size.

The display device according to the present invention performs a size conversion process of the input video based on the means for receiving the input video, the means for specifying the aspect ratio of the input video, and the detected aspect ratio and the aspect ratio of the display And means for specifying the aspect ratio of the input video based on the aspect ratio, and the aspect ratio information is superimposed on the input video when aspect ratio information is superimposed on the input video. If not, the number of lines of the input video is detected. When the detected number of lines is 720 or 1080, the aspect ratio is specified as 16: 9, and when the number is not, the aspect ratio is 4: 3. It is characterized by specifying that there is.

  As described above, according to the present invention, the screen size (format) of the input video can be estimated without performing complicated processing on the video, and the input video is converted into the screen size of the display based on this estimation. Can be converted to a suitable size. In addition, when the screen size information (format information) is superimposed on the video, the information is prioritized, and the estimation is performed when there is no such information. . Further, if the configuration allows the screen size to be switched by the user instruction, the video can be converted to an appropriate size by the user instruction even when the error occurs.

  Hereinafter, a display device according to an embodiment of the present invention will be described with reference to FIGS. Note that the display device of this embodiment is configured as a digital broadcast receiving device that receives satellite digital broadcasts, and has a configuration capable of displaying an image by inputting an external video signal. FIG. 1 is a block diagram showing the configuration of the digital broadcast receiving apparatus, FIG. 2 is a flowchart showing the processing contents, and FIG. 3 is a video screen when the display screen size is 16: 9. FIG. 4 is an explanatory diagram showing an example of the relationship between the size and the display video, and FIG. 4 is an explanatory diagram showing an example of the relationship between the video screen size and the display video when the screen size of the display is 4: 3. Out.

  As shown in FIG. 1, the antenna 1 is arranged outdoors in a predetermined direction, and receives a digital broadcast signal sent from a satellite. This antenna 1 is generally provided with a frequency converter, and supplies a received / frequency converted signal to a digital tuner 2.

  The digital tuner 2 extracts a signal of a specific frequency from the high frequency digital modulation signal including video / audio data. That is, a process of selecting one from a plurality of transponders of digital broadcasting is performed. In addition, the digital tuner 2 includes a demodulation circuit, a deinterleave circuit, an error correction circuit, and the like, thereby demodulating the selected digital modulation signal and outputting a transport stream. The digital tuner 2 includes a demultiplexer (DEMUX) (not shown). The demultiplexer separates the transport stream into an MPEG2 (Moving Picture Experts Group 2) video stream, an audio stream, and PSI / SI (Program Specific Information / Service Information). The demultiplexer supplies the video stream and the audio stream to the AV decoder 3 and supplies program information (program name, program content information, program genre information, etc.) included in the PSI / SI to the CPU 10.

  The AV decoder 3 includes a video decoder that decodes a video stream and an audio decoder that decodes an audio stream. The video decoder decodes the input variable length code to obtain a quantization coefficient and a motion vector, and performs video compensation by performing inverse DCT transformation, motion compensation control based on the motion vector, and the like. The audio decoder decodes the input encoded signal to generate audio data. In this embodiment, the AV decoder 3 includes a D / A converter, and the video data and the audio data are converted into analog signals (for example, Y, Pb, Pr component signals for video and left and right stereo for audio). Signal) and output.

  The input switching circuit 4 inputs an analog video signal and an audio signal from the AV decoder 3 and an analog video signal (for example, Y, Pb, etc.) supplied from an external device (for example, a DVD player) 11. Pr component signals) and audio signals (for example, left and right stereo signals) are input. Then, one of the video / audio signals is selected and output in accordance with a command from the CPU 10. The audio signal is subjected to processing such as amplification by the audio amplifier 8 and supplied to the speaker 9. The video signal is supplied to the frequency detection circuit 5.

  The frequency detection circuit 5 receives an analog video signal and determines the number of lines of the video signal. For example, the number of horizontal synchronization signals detected in 1V (vertical period) is counted. Then, a count value which is the detection result (the number of video signal lines) is supplied to the CPU 10.

  The video output circuit 6 performs A / D conversion on the video signal that has passed through the frequency detection circuit 5, and performs video signal generation processing (such as addition of a blank area) according to the screen size of the video signal and the screen size of the display 7. Scale conversion processing (see FIGS. 3 and 4) according to video enlargement based on a user instruction, on-screen display processing for superimposing characters and images on the video, and the like are performed. The screen size information of the video signal in the video signal generation process, the conversion ratio information in the scale conversion, the character information and the layout information in the on-screen display process are given from the CPU 10. Further, the video output circuit 6 performs, for example, NTSC encoding on the processed digital video signal to generate an NTSC signal, and supplies the NTSC signal to the display 7.

  The CPU 10 determines the screen size of the video signal based on the count value supplied from the frequency detection circuit 5. For example, when “720” is obtained as the count value or “1080” is obtained as the count value, it is estimated that the screen size of the video signal is 16: 9, and when the other count values are obtained, the screen of the video signal is obtained. The size is estimated to be 4: 3. Then, the screen size information as the estimation result is given to the video output circuit 6. When screen size information (aspect ratio information) is superimposed on the received digital broadcast wave, the screen size information is separated by the digital tuner 2 and supplied to the CPU 10. Therefore, when the CPU 10 obtains the screen size information from the digital tuner 2, the CPU 10 gives priority to the screen size information. In other words, when the screen size information superimposed on the video signal can be acquired, the screen size of the video is determined based on the information. On the other hand, when the screen size information is not superimposed on the video signal, Based on the output of the frequency detection circuit 5, processing for estimating the screen size of the video is performed.

  The processing contents are shown in the flowchart of FIG. First, it is determined whether or not the screen size information is superimposed on the video signal (step S1). When the screen size information is superimposed, the video is displayed based on the screen size of the video indicated by the information and the screen size of the display 7. Processing to an appropriate size (step S2). If not superimposed, it is determined whether the video format is 720p or 1080i based on the output of the frequency detection circuit 5 (step S3). If YES is obtained, the video screen size is 16: 9. And the video is processed into an appropriate size (step S4). On the other hand, when the determination of NO is obtained, it is estimated that the screen size of the video is 4: 3, and the video is processed into an appropriate size (step S5).

  By the way, by adding a side panel to the 4: 3 standard video, it becomes a 16: 9 video, and this 16: 9 video may be transmitted at 720p. It may be transmitted at 720p without adding a side panel. In such a case, the screen size of the video is estimated to be 16: 9 based on the output of the frequency detection circuit 5. Therefore, in view of the occurrence of such a situation, the user is allowed to switch the screen size, and the user determines that the screen size of the video is 16: 9 and is displayed by the user. When there is an instruction to switch the screen size, the displayed video may be processed as a 4: 3 video. That is, the CPU 10 gives the estimation result that the screen size is 4: 3 to the video output circuit 6 and then detects that the screen size switching key of the remote control transmitter is pressed, the screen size is 4: 3. Information may be reapplied to the video output circuit 6. To repeat, the processing is based on the assumption that the screen size of the video is 16: 9 when the detection output of the frequency detection circuit 5 indicates 720p, and 4: 3 when the screen size switching instruction is received. You may make it switch to the process with respect to this image | video. It should be noted that when the video is being processed based on the screen size information superimposed on the video signal, it is preferable not to perform the switching as described above even if the screen size switching instruction is received.

1 is a block diagram showing a digital broadcast receiver (display device) according to an embodiment of the present invention. It is the flowchart which showed the processing content of this invention. It is explanatory drawing which showed the example of a screen display by the process of this invention. It is explanatory drawing which showed the example of a screen display by the process of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna 2 Digital tuner 3 AV decoder 4 Input switching circuit 5 Frequency detection circuit 6 Video output circuit 10 CPU

Claims (1)

Means for receiving the input video;
Means for specifying an aspect ratio of the input video;
Means for performing a size conversion process of the input video based on the detected aspect ratio and the aspect ratio of the display;
The means for specifying is
When aspect ratio information is superimposed on the input video, the aspect ratio of the input video is specified based on the aspect ratio,
When the aspect ratio information is not superimposed on the input video, the number of lines of the input video is detected, and when the detected number of lines is 720 or 1080, the aspect ratio is specified as 16: 9, otherwise The display device is characterized in that the aspect ratio is specified as 4: 3 .

Images