JP2002135665A - Digital broadcasting receiving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the circuit scale of a liquid crystal TV receiver and to reduce the cost in a digital broadcasting receiving system. SOLUTION: The liquid crystal TV receiver is provided with a horizontal/ vertical resolution information generating block 220. The CPU 109 of a digital broadcasting tuner automatically recognizes the horizontal/vertical resolution of a liquid crystal panel in the liquid crystal TV receiver via the horizontal/ vertical resolution information signal line c of a D terminal cable m, and a format conversion block 104 is controlled. Then the video signal of a video format, which is suitable for the horizontal/vertical resolution of the liquid crystal TV receiver, is transmitted and an image size adjusting circuit is dispersed with at the side of the liquid crystal TV receiver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to satellite broadcasting (Broadca).
sting Satellite (hereinafter abbreviated as BS) a digital broadcast tuner having a digital broadcast receiving function of broadcasting as waves or terrestrial waves, and a liquid crystal television having a function of receiving digital broadcast video and audio signals demodulated and decoded by the digital broadcast tuner. The present invention relates to a digital broadcast receiving system including a receiver.

[0002]

[Prior Art] Digital broadcasting has already started in Europe and the United States for several years, and in Japan, BS digital broadcasting has started in December 2000, and terrestrial digital broadcasting has started in 2003 in the Kanto, Chukyo, and Kinki regions. It will be done.

As a system for receiving such a digital broadcast, for example, there is a system configured by a combination of a digital broadcast tuner and a liquid crystal television receiver. In this configuration, the digital broadcast tuner and the liquid crystal television receiver are connected by a D terminal and a D terminal cable standardized by the Japan Electronic Machinery Manufacturers Association, so that analog component video signals can be transmitted. The user can enjoy a screen with higher image quality than the conventional composite signal.

The configuration and operation of a conventional digital broadcast receiving system will be described with reference to FIG. 1 is a digital broadcast tuner. A digital demodulation 101 receives a digital broadcast wave from an antenna in the digital broadcast tuner 1, selects a necessary channel, performs demodulation processing and error correction processing, and outputs the result as a transport stream signal (hereinafter abbreviated as a TS signal). It is a block. TS
The signal is obtained by multiplexing coded video data, audio data, and the like into digital data in a digital broadcast transmission facility of a broadcasting station, for example.

[0005] Reference numeral 102 denotes a TS separation block for separating the TS signal output from the digital demodulation block 101 into encoded video signals, audio signals, and the like. Reference numeral 103 denotes a video decoding block for returning the coded video signal output from the TS separation block 102 to the original signal. Reference numeral 104 denotes a format conversion block that converts the data into a prescribed video format and outputs the digital component video signal. Reference numeral 105 denotes a video DAC that performs digital-to-analog conversion (hereinafter, abbreviated as D / A conversion) of the digital component video signal that has been format-converted from the format conversion block 104 and outputs the analog component video signal.

Reference numeral 106 denotes a D terminal for outputting an analog component video signal output from the video DAC 105 from a prescribed pin. Reference numeral 107 denotes an audio decoding block that decodes the separated encoded audio signal output from the TS separation block 102. 108 is audio decoding block 1
This is a voice DAC that D / A converts the decoded digital voice signal from 07 and outputs it as an analog voice signal. 109
Is a CPU for controlling each block inside the digital broadcast tuner 1 as described above.

Reference numeral 2 denotes a liquid crystal television receiver. Reference numeral 201 denotes a D terminal for receiving an analog component video signal from the D terminal 106 of the digital broadcast tuner 1 via a D terminal cable. Reference numeral 202 denotes a video ADC that receives an analog component video signal from the D terminal 201, converts the analog component video signal into an analog-to-digital signal (hereinafter, abbreviated as A / D conversion), and converts the signal into a digital component signal. Reference numeral 203 denotes a video signal processing block that performs image quality correction, interlaced progressive conversion, and the like on the digital component video signal from the video ADC 202. Reference numeral 204 denotes an image size adjustment block for adjusting the display image size of the digital component video signal from the video signal processing block 203 so as to match the horizontal / vertical resolution of the liquid crystal panel.

Reference numeral 205 denotes a matrix conversion block for performing matrix processing and the like for returning the digital component video signal from the image size adjustment block 204 to primary color RGB signals. A sync 206 separates a horizontal / vertical sync signal from a luminance signal (hereinafter abbreviated as a Y signal) of a part of the digital component video signal from the video ADC 202, and generates a display clock synchronized with the horizontal sync signal. It is a signal processing block. 207 is the primary color R from the matrix conversion block 205
The liquid crystal panel displays an image based on the horizontal and vertical synchronizing signals from the synchronizing signal processing block 206 and the display clock.

Reference numeral 208 denotes an audio DAC of the digital broadcast tuner 1
An audio amplification block for adjusting the gain of the audio signal from 108. Reference numeral 209 denotes a speaker for reproducing the gain-adjusted audio signal from the audio amplification block 208. Reference numeral 210 denotes a CPU for controlling each block in the liquid crystal television receiver 2 as described above. Further, between the digital broadcast tuner 1 and the liquid crystal television receiver 2, an analog component video signal is transmitted via a D terminal cable m, and an audio signal is transmitted via an audio cable n.

The operation of the above configuration will now be described.

When the user instructs the digital broadcast tuner 1 on a channel desired by the user with a remote controller or the like, the CPU 109
, The digital demodulation block 101 selects the designated channel from the digital broadcast wave input from the antenna input, performs digital demodulation and error correction processing, and
The signal is output to the TS separation block 102 as an S signal. The TS separation block 102 separates the TS signal into a coded video signal and audio signal, and sends them to the video decoding block 103 and the audio decoding block 107, respectively.

The video decoding block 103 decodes the coded video signal, and further performs a format conversion corresponding to the video format mode specified by the CPU 109 in the format conversion block 104 to the video DAC 105 as a digital component video signal. Send out.
The video DAC 105 converts the input digital component video signal into an analog component video signal and
Output to 06. The encoded audio signal output from the TS separation block 102 is
Is decoded into a digital audio signal at 7 and the next stage audio DAC 10
The signal is converted into an analog audio signal by 8 and transmitted to the television receiver 2 via an audio cable.

The CPU 109 is a digital demodulation block 101
In addition to the channel selection control, the processing sequence of each block in the digital broadcast tuner 1 is controlled. In the liquid crystal television receiver 2, an analog component signal is transmitted from the D terminal 106 of the digital broadcast tuner 1 to the video ADC 202 through the D terminal cable m and the D terminal 201. Video ADC2
In 02, the received analog component video signal is converted into a digital component video signal. The video signal processing block 203 performs image quality correction, interless progressive conversion, and the like on the digital component video signal from the video ADC 202.

The digital component video signal, which has been subjected to image quality correction and the like in the video signal processing block 203, is adjusted in display image size in the image size adjustment block 204, and is sent to the matrix conversion block 205. The matrix conversion block 205 converts the sent component video signal into a primary color RGB signal and sends it to the liquid crystal panel 207. On the other hand, in the synchronization signal processing block 206, the video ADC
A Y signal is input from 202 to separate a horizontal / vertical synchronization signal, generate a display clock synchronized with the separated horizontal synchronization signal, and send it to the liquid crystal panel 207.

In the liquid crystal panel 207, the primary color RGB signal from the matrix conversion block 205 and the synchronization signal processing block 206
Based on the horizontal and vertical synchronizing signals and the display clock from the camera, an image transmitted by digital broadcasting is displayed on the panel.
Further, the analog audio signal from the digital broadcast tuner 1 is sent to the audio amplification block 208 via the audio cable n, and is reproduced as audio by the speaker 209 after gain adjustment. Note that the CPU 210 is a liquid crystal television receiver 2
And controls the processing sequence of each block in the block.

The operation of the conventional digital broadcast receiving system shown in FIG. 2 has been described above.

Further, a more detailed configuration around the D terminal and D terminal cable and its operation of a conventional digital broadcast receiving system directly related to the present invention will be described with reference to FIG.

The description of the configuration and operation of the blocks having the same numbers as those in FIG. 2 will be omitted. D terminal 106 and D
The terminals 201 are connected by a D terminal cable m. In the D terminal cable m, in addition to the analog component video signal line a transmitting the analog component video signal,
An identification signal line b for transmitting an identification signal indicating information on the format and aspect ratio of the analog component video signal
Exists. The identification signal is output from, for example, the output port of the CPU 109, and is input to the input port of the CPU 210 via the D terminal 106, the identification signal line b, and the D terminal 201.

Next, the operation will be described. The CPU 109 specifies a video format mode after decoding the video signal to the format conversion block 104, and at the same time, uses the video format mode as an identification signal as a D terminal 106,
The signal is transmitted to the liquid crystal television receiver 2 via the identification signal line b. In the liquid crystal television receiver 2, the CPU 210 reads the identification signal via the D terminal 201, and regulates the image size in the image size adjustment block 204 based on the information.

The video format in digital broadcasting is defined as shown in Table 1.

[0021]

[Table 1]

In Table 1, the number of scanning lines refers to the number of horizontal scanning lines in the vertical synchronization period, and the number of effective scanning lines refers to the number of horizontal scanning lines including actual images. The interlace is an interlaced scanning, and is a method of transmitting an image A by skipping one horizontal scanning period at a time and then transmitting an image B in the skipped horizontal scanning period. Progressive refers to progressive scanning, which is a method of sequentially scanning one horizontal scanning period and transmitting an image. In Table 1, for example, when the number of scanning lines is 525 and the number of effective scanning lines is 480 and the interlace method is used, it is expressed as 525i.

[0023]

In a digital broadcast receiving system comprising such a digital broadcast tuner and a liquid crystal television receiver, the digital broadcast tuner recognizes the video format of the received digital broadcast program and is connected to the digital broadcast tuner. Output an analog component video signal corresponding to the receiving capability of the liquid crystal television receiver. As the reception capability of the liquid crystal television receiver, it is assumed that various levels such as those capable of receiving up to 1125i and those capable of receiving only up to 525i are used. As shown in Table 2, the reception level is defined as D1 to D5 so that the user can clearly indicate to which video format the same D terminal can support.

[0024]

[Table 2]

For example, if the video format of the received digital broadcast program is 1125i and the reception level of the liquid crystal television receiver is D2, the digital broadcast tuner converts the video format to 525p or 525i and outputs it.

However, in the case of a liquid crystal television, it is necessary to match the image format of the video signal, that is, the horizontal / vertical resolution with the horizontal / vertical resolution of the liquid crystal panel. Therefore, since the format conversion (image size adjustment) is performed again on the liquid crystal television and displayed on the liquid crystal panel, an image size adjustment circuit and a frame memory are required, which causes an increase in the number of parts and an increase in cost. .

Further, as disclosed in Japanese Patent Application Laid-Open No. 2000-175120, it is determined on the receiving side whether or not the input television signal can be decoded from the frequency of the horizontal / vertical synchronization signal. Although a method of receiving a television signal down-converted to a level that can be decoded is disclosed, even in this case, there is no guarantee that a video signal in a format that matches the horizontal and vertical resolutions of the liquid crystal panel can be obtained.

[0028]

In order to solve the above-mentioned problems, a digital broadcast receiving system according to the present invention is a digital broadcast tuner for receiving a digital broadcast by a broadcast satellite or a terrestrial wave and demodulating and decoding the digital broadcast into a video signal and an audio signal. And a liquid crystal television receiver having a function of receiving the video signal from the digital broadcast tuner via a D terminal as an analog component video signal. The horizontal and vertical resolution of the LCD panel
The digital broadcast tuner has means electrically readable from the liquid crystal television receiver, and the digital broadcast tuner has means for horizontally moving the liquid crystal panel of the liquid crystal television receiver by the electrically readable means. A vertical resolution is read, and the analog component video signal in a format suitable for the read horizontal / vertical resolution is output.

According to the present invention, the digital broadcast tuner automatically reads the horizontal / vertical resolution of the panel of the liquid crystal television receiver by using means electrically readable from the liquid crystal television receiver. In order to transmit the demodulated and decoded video signal in a video format suitable for the horizontal and vertical resolutions of the liquid crystal panel of the liquid crystal television receiver, the liquid crystal television receiver does not have an image size adjustment circuit. Thus, it is possible to provide a digital broadcast receiving system capable of displaying an optimal image on a liquid crystal panel.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a digital broadcast tuner for receiving a digital broadcast by a broadcast satellite or a terrestrial wave and demodulating and decoding it into a video signal and an audio signal. A digital broadcast receiving system comprising a liquid crystal television receiver having a function of receiving the video signal as an analog component video signal via a D terminal.
The digital broadcast tuner has means for electrically reading the vertical resolution from the liquid crystal television receiver, and the liquid crystal of the liquid crystal television receiver is provided to the digital broadcast tuner by the electrically readable means. Reading the horizontal and vertical resolution of the panel, and outputting the analog component video signal in a format adapted to the read horizontal and vertical resolution, wherein the digital broadcast tuner is transmitted from the liquid crystal television receiver. The horizontal / vertical resolution of the panel of the liquid crystal television receiver is automatically read using an electrically readable means, and the demodulated and decoded video signal is read horizontally by the liquid crystal panel of the liquid crystal television receiver.・ To transmit in the video format compatible with the vertical resolution, Optimal image does not have to include the image size adjustment circuit vision receiver can provide a digital broadcast receiving system can be displayed on the liquid crystal panel.

(Embodiment 1) The first aspect of the present invention will be described below.
The embodiment of the invention described in (1) will be described with reference to FIG. However, description of blocks and signal lines having the same numbers as those described in the conventional example will be omitted.

FIG. 1 is a block diagram of a digital broadcast receiving system according to the present invention around a D terminal and a D terminal cable.

In FIG. 1, reference numeral 220 denotes a horizontal / vertical resolution information generation block which outputs horizontal / vertical resolution information of the liquid crystal panel of the liquid crystal television receiver 2. c is a horizontal / vertical resolution information signal line for transmitting horizontal / vertical resolution information within the D terminal cable m. The horizontal / vertical resolution information generation block 220, the D terminal 201, the horizontal / vertical resolution information signal line c in the D terminal cable m, and the D terminal 106 digitally broadcast the horizontal / vertical resolution information of the liquid crystal panel of the liquid crystal television receiver 2. Means by which the tuner 1 can be electrically read from the liquid crystal television receiver 2 is formed.
D terminal to which a horizontal / vertical resolution information signal is input so that the CPU 109 can read the horizontal / vertical resolution information of the liquid crystal television receiver 2 by the electrically readable means.
The terminal 106 and the input port of the CPU 109 are connected.

Next, the operation of the digital broadcast receiving system having the above configuration will be described. CPU109 is D terminal 20
1. The horizontal / vertical resolution information is read from the horizontal / vertical resolution information generation block 220 via the horizontal / vertical resolution information signal line c and the D terminal 106 in the D terminal cable m, and the liquid crystal panel of the liquid crystal television receiver 2 is read. Automatically recognize horizontal and vertical resolution information. Next, based on the recognized horizontal and vertical resolution information of the liquid crystal panel of the liquid crystal television receiver 2, the CPU 109 instructs the format conversion block 104 to display a video format suitable for the horizontal and vertical resolution of the liquid crystal panel of the liquid crystal television receiver 2. Instruct conversion. The format conversion block 104, according to the instruction from the CPU 109,
Performs format conversion of the decoded video signal. The digital component video signal that has been format-converted by the format conversion block 104 is converted into an analog component video signal by the video DAC 105, and is again converted into a digital component video signal by the video ADC 202 via the D terminal 106, the D terminal cable m, and the D terminal 201. The signal is returned to the video signal processing block 203 and the synchronization signal processing block 206. Video signal processing block 203 and synchronization signal processing block 2
The digital component video signal sent to 06 is sent to a subsequent processing block after processing such as image quality correction and synchronization separation, and an image is formed on the liquid crystal panel.

[0035]

As described above, according to the digital broadcast receiving system of the present invention, the digital broadcast tuner can automatically read the horizontal and vertical resolutions of the liquid crystal panel of the liquid crystal television receiver. Equipped with an image size adjustment circuit on the liquid crystal television receiver side to send the demodulated and decoded video signals to the liquid crystal television receiver in a video format compatible with the horizontal and vertical resolution of the liquid crystal panel of the liquid crystal television receiver Even if it is not, an optimal image can be displayed on the liquid crystal panel, and the circuit scale and cost of the liquid crystal television receiver can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a video signal transmission system of a digital broadcast receiving system according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a conventional digital broadcast receiving system.

FIG. 3 is a block diagram of a video signal transmission system of a conventional digital broadcast receiving system.

[Explanation of symbols]

 220 Horizontal / vertical resolution information generation block c Horizontal / vertical resolution information signal line

Claims (1)

[Claims] 1. A digital broadcast tuner for receiving a digital broadcast by a broadcast satellite or a terrestrial wave and demodulating and decoding it into a video signal and an audio signal, and the video signal from the digital broadcast tuner as an analog component video signal via a D terminal. In a digital broadcast receiving system including a liquid crystal television receiver having a function of receiving, the horizontal / vertical resolution of the liquid crystal panel of the liquid crystal television receiver is adjusted by the digital broadcast tuner from the liquid crystal television receiver. An electronically readable means, wherein the digital broadcast tuner reads the horizontal and vertical resolution of the liquid crystal panel of the liquid crystal television receiver by the electrically readable means, and the read horizontal and vertical resolution The analog component in a format suitable for A digital broadcast receiving system for outputting a video signal.