JP2002152608A - Digital broadcast receiving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent display failure due to the discrepancy between the output video format of a digital broadcast tuner and the receiving level of a television receiver in a digital broadcast receiving system. SOLUTION: A television receiver video inputting part 220 is provided with a receiving level code generation block 210, the CPU 108 of a digital broadcast tuner video outputting part 110 recognizes the received level of the television receiver through the receiving level code signal lien (c) of a D terminal cable (m) and controls a video decode format conversion block 103, and a video signal of a video format fitting the receiving level of the television receiver can thereby be transmitted.

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 (abbreviated as BS) Digital broadcast tuner that has a digital broadcast receiving function of broadcasting as waves or terrestrial waves, and a television receiver that has 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 composed of a personal computer.

[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 television receiver. In this configuration, an analog component video signal can be transmitted by connecting a digital broadcast tuner and a television receiver with a D terminal and a D terminal cable standardized by the Japan Electronic Machinery Manufacturers Association. 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 decode / format conversion block that decodes the coded video signal output from the TS separation block 102, converts the coded video signal into a specified video format, and outputs the converted video signal as a digital component video signal. Reference numeral 104 denotes a video DAC that performs digital-to-analog conversion (hereinafter, abbreviated as D / A conversion) on the digital component video signal that has been format-converted from the video decode / format conversion block 103 and outputs the analog component video signal. 1
05 is a D terminal for outputting an analog component video signal output from the video DAC 104 from a prescribed pin.

[0006] Reference numeral 106 denotes an audio decoding block for decoding the separated encoded audio signal output from the TS separation block 102. An audio DAC 107 D / A converts the digital audio signal decoded from the audio decoding block 106 and outputs it as an analog audio signal. 1
Reference numeral 08 denotes a CPU for controlling each block inside the digital broadcast tuner 1 as described above.

[0007] Reference numeral 2 denotes a television receiver. Reference numeral 201 denotes a D terminal for receiving an analog component video signal from the D terminal 105 of the digital broadcast tuner 1 via a D terminal cable. Reference numeral 202 denotes a video signal processing block that receives an analog component video signal from the D terminal 201 and performs image quality correction, image size adjustment, and the like. Reference numeral 203 denotes a color output block for performing a matrix process or the like for returning a component video signal to a primary color RGB signal. 204 is a luminance signal of a part of the analog component video signal from the D terminal 201
This is a synchronization signal processing block that separates a horizontal / vertical synchronization signal from a signal (hereinafter, abbreviated as a Y signal).

Reference numeral 205 denotes a horizontal / vertical deflection block for outputting a horizontal / vertical deflection signal based on the horizontal / vertical synchronization signal from the synchronization signal processing block 204. 206 is color output block 2
A picture tube (hereinafter abbreviated as CRT (Cathode Ray Tube)) that forms an image by horizontally and vertically deflecting the primary color RGB signal from 03 using the horizontal and vertical deflection signals from the horizontal and vertical deflection block 205
It is. 207 is an audio DAC 107 of the digital broadcast tuner 1
This is an audio amplification block for adjusting the gain of the audio signal from the audio amplifier.

Reference numeral 208 denotes a speaker for reproducing the gain-adjusted audio signal from the audio amplification block 207. 20
Reference numeral 9 denotes a CPU for controlling each block inside the television receiver 2 as described above. Further, between the digital broadcast tuner 1 and the 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 the channel desired by the user with a remote controller or the like, the CPU 108
, 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 a video decode / format conversion block 103 and an audio decode block 106, respectively.

Video decoding / format conversion block
In 103, the encoded video signal is decoded, the format is converted in accordance with the video format mode specified by the CPU 108, and the decoded video signal is transmitted to the video DAC 104 as a digital component video signal. The video DAC 104 converts the input digital component video signal into an analog component video signal and outputs it to the D terminal 105. The encoded audio signal output from the TS separation block 102 is decoded into a digital audio signal by an audio decoding block 106, converted into an analog audio signal by an audio DAC 107 at the next stage, and received by a television receiver via an audio cable. Is transmitted to the device 2.

The CPU 108 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 television receiver 2, the analog component signal is transmitted from the D terminal 105 of the digital broadcast tuner 1 to the D terminal cable m, D
The signal is sent to the video signal processing block 202 through the terminal 201.
The video signal processing block 202 performs image quality correction, image size adjustment, and the like, and sends the processed component video signal to the color output block 203. The color output block 203 converts the transmitted component video signal into a primary color RGB signal and sends it to the RGB input terminal of the CRT 206.

On the other hand, in the synchronization signal processing block 204, D
A Y signal is input from a terminal 201 to separate a horizontal / vertical synchronization signal, which is sent to a horizontal / vertical deflection block 205 at a subsequent stage. The horizontal / vertical deflection block 205 generates horizontal / vertical deflection signals based on the horizontal / vertical synchronization signals from the synchronization signal processing block 204 and sends them to the CRT 206. In the CRT 206, an electron beam modulated by a primary color RGB signal sent to an RGB input terminal is deflected by horizontal and vertical deflection signals to form an image transmitted by digital broadcasting on the CRT 206 screen.

An analog audio signal from the digital broadcast tuner 1 is sent to an audio amplifier block 207 via an audio cable n and, after gain adjustment, is reproduced as audio by a speaker 208. The CPU 209 controls the processing sequence of each block in the television receiver 2 and the like.

The operation of the conventional digital broadcast receiving system shown in FIG. 3 has been described above.

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

Reference numeral 110 denotes a digital broadcast tuner video output unit. The digital broadcast tuner 1 has a video decode / format conversion block 103, a video DAC 104, a CPU 108,
It is assumed that the terminal 105 is used. Reference numeral 220 denotes a television receiver video input unit, and a D terminal of the television receiver 2
201, video processing block 202, synchronization signal processing block 20
4. Assume that the CPU 209 is used.

The D terminal 105 and the D terminal 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 for transmitting the analog component video signal, There is an identification signal line b for transmitting an identification signal indicating the format and aspect ratio information. 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 processing of the component video signal is the same as that described above with reference to FIG. The CPU 108 designates the video format mode after decoding the video signal to the video decoding / format conversion block 103, and at the same time, uses the video format mode as an identification signal through the D terminal 105 and the identification signal line b to the television receiver 2. To send to. In the television receiver 2, the CPU 209 reads the identification signal via the D terminal 201, and regulates the image size adjustment in the video signal processing block 202 based on the information.

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

[0022]

[Table 1]

In Table 1, the number of scanning lines refers to the number of horizontal scanning lines during 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 scan, 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.

[0024]

In a digital broadcast receiving system composed of such a digital broadcast tuner and a television receiver, the receiving capability of the television receiver is, for example, one capable of receiving up to 1125i, 525i. It is assumed that various levels are used, such as those that can only be received up to a maximum. 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. The digital broadcast tuner outputs an analog component video signal corresponding to the reception level of the television receiver.

[0025]

[Table 2]

However, in order to output an analog component video signal corresponding to the receiving capability of the television receiver to which the digital broadcast tuner is actually connected, for example, after actually connecting and turning on the power, the remote control of the digital broadcast tuner is used. Must be set as one of the initial settings. In most cases, the initial setting using the remote control needs to be displayed as a menu on the screen and operated.For example, the analog component video signal format output by the digital broadcast
If it is set to 1125i and the television receiver connected to the digital broadcast tuner has only the D2 mode, that is, the reception capability up to 525p, the screen will flow even if the power is turned on, and the image will not be displayed normally.

Therefore, the menu screen for the initial setting is not displayed, and there is a possibility that the analog component video signal suitable for the receiving capability of the television receiver to which the digital broadcast tuner is connected cannot be output. In some cases, a switch for setting an output format is provided in the digital broadcast tuner. In this case, however, a normal user is forced to understand a complex digital broadcast component video signal format and set it correctly. Otherwise, the screen is not normally displayed on the television receiver immediately after the power is turned on, and there is a possibility that a misunderstanding may be given that some trouble has occurred.

In order to avoid these problems, a method in which the output of the digital broadcast tuner is set to the D1 mode (525i) in advance at the time of shipment from the factory so as to always display normally on any television receiver However, for example, in BS digital broadcasting and terrestrial digital broadcasting, the video mode on the broadcasting side is mostly broadcast in 1125i with high image quality, and the television receiver side will be able to receive up to 1125i, for example. While there is a great possibility that the number of receivers that support the resolution mode will increase, the screen immediately after the digital broadcast tuner is installed will always be displayed in the low resolution of the 525i mode, and the digital broadcast detracts from the image of high image quality. Also in this case, there is also a complication that a normal user must understand and correctly set a complex digital broadcast component video signal format.

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. A system for receiving a television signal down-converted to a level that can be decoded is disclosed. In this case, the receiver must determine whether decoding is possible,
The determination circuit and procedure become complicated, and a switch circuit is required for the switching process after the determination.

[0030]

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 television receiver having a function of receiving the video signal from the digital broadcast tuner as an analog component video signal via a D terminal, wherein the television receiver can receive the video signal. The digital broadcast tuner has means capable of electrically reading the modes from D1 to D5 indicating the range of the video format of the digital broadcast, from the television receiver, and the digital broadcast tuner is capable of electrically reading the modes. Modes from D1 to D5 by possible means Of the read or television receiver corresponds to which mode is obtained by and outputs the analog component video signals conforming to the read mode.

According to the present invention, the digital broadcast tuner automatically reads the reception mode of the television receiver by using means electrically readable from the television receiver at the time of installation or replacement of equipment. , The demodulation
In order to transmit the decoded video signal in a video format suitable for the reception level of the television receiver,
It is possible to provide a digital broadcast receiving system capable of avoiding a screen display defect due to a mismatch between a video format and a reception level at the time of installation or device replacement.

[0032]

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. In a digital broadcast receiving system configured with a 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 a mode from D1 to D5 indicating a range of a digital broadcast video format receivable by the television receiver from the television receiver. A broadcast tuner reads which of the modes D1 to D5 corresponds to which mode of the television receiver by the electrically readable means, and outputs the analog component video signal suitable for the read mode. Even if the received digital broadcast has a video format exceeding the reception level of the television receiver, the digital broadcast tuner is capable of receiving the television broadcast at the time of installation or equipment replacement. Automatically using the electronically readable means from the machine. By reading which mode from D1 to D5 of the television receiver, and transmitting the demodulated and decoded analog component video signal in a video format suitable for the reception level of the television receiver, It is possible to avoid a screen display defect due to a mismatch between a video format and a reception level at the time of replacement of a device.

Next, according to a second aspect of the present invention, in the first aspect of the present invention, the digital broadcast tuner serves as an electrically readable means from the D terminal of the television receiver. A code corresponding to the mode from D1 to D5 is output, and a control CPU in the digital broadcast tuner is configured to output a code corresponding to the D of the television receiver.
Reading the code via a D terminal cable connected to a terminal, wherein the digital broadcast tuner is connected to the D1 of the television receiver.
By reading the codes corresponding to the modes from D to D5 via the D terminal cable, it is not necessary to add a cable for reading the codes, so that the installation work can be simplified and the cost can be reduced.

Next, the invention according to claim 3 of the present invention is characterized in that, in the invention according to claim 2, when all bits are 0 or 1 as a code corresponding to the modes from D1 to D5, A code is assigned to the D terminal of the television receiver so that it can be determined that the digital broadcast tuner does not have an electrically readable means, and a terminal to which the code of the D terminal on the digital broadcast tuner side is input. Are all pulled up or pulled down, and whether the digital broadcast tuner has means for electrically reading the digital broadcast tuner at the D terminal of the television receiver. Can be determined so as to match the reception level of the television receiver that does not have the electrically readable means. It is possible to prevent the sending analog component video signal without video format.

(Embodiment 1) The first aspect of the present invention will be described below.
An embodiment of the invention described in claim 2 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 showing a D terminal and a D terminal cable m of a digital broadcast receiving system according to the present invention. The digital broadcast tuner video detecting section 110 and the television receiver video input section 220 are respectively a part of the digital broadcast tuner 1 and the television receiver 2 as shown in the figure of the conventional example.

In FIG. 1, reference numeral 210 denotes a reception level code generation block, which is a code corresponding to any of D1 to D5 modes indicating a video format range of an analog component video signal that can be received by the video input unit 220 of the television receiver. Is output. c is a reception level code signal line for transmitting a reception level code signal within the D terminal cable m. Reception level code generation block 210,
The D terminal 201, the reception level code signal line c in the D terminal cable m, and the D terminal 105 set the modes from D1 to D5.
Means are formed which can be read electrically. The terminal of the D terminal 105 to which the reception level code signal is input is connected to the input port of the CPU 108 so that the CPU 108 can read the reception level code of the television receiver 2 by the electrically readable means.

Next, the operation of the digital broadcast receiving system having the above-described configuration when the digital broadcast receiving system is installed or when the equipment is replaced will be described. After turning on the power to the digital broadcast receiving system,
The CPU 108 reads the reception level code from the reception level code generation block 210 via the D terminal 201, the reception level code signal line c in the D terminal cable m, and the D terminal 105,
The television receiver 2 automatically recognizes the range of the video format that can be supported.

Next, the CPU 108 instructs the video decoding / format conversion block 103 to perform video format conversion adapted to the reception level of the television receiver 2 based on the recognized video format reception level. The video decoding / format conversion block 103 converts the format of the decoded video signal in accordance with an instruction from the CPU 108. For example, for the television receiver 2 having a reception level of D2, the video signal is converted into a 525p video format. It is converted into a video format that can be received by the television receiver 2. The digital component video signal decoded and format-converted by the video decode / format conversion block 103 is converted into an analog component video signal by the video DAC 104.
The signal is sent to the video signal processing block 202 and the synchronization signal processing block 204 via the terminal cable m and the D terminal 201.

The analog component video signal sent to the video signal processing block 202 and the synchronization signal processing block 204 is sent to a subsequent processing block after processing such as image quality correction and synchronization separation, and an image is formed on the CRT screen. Will be. In this case, first, the CP of the digital broadcast tuner 1 side
Since the U108 can recognize the reception level of the television receiver 2, the video format of the analog component video signal sent to the television receiver 2 is surely the video signal processing block 2 or the synchronization signal processing block of the television receiver 2. It can be processed by. Further, since the reception level code signal line passes through the D terminal cable, it is not necessary to add a cable or the like.

(Embodiment 2) Next, an embodiment of the invention described in claim 3 of the present invention will be described with reference to Table 3 and FIG.

[0042]

[Table 3]

Table 3 is an example of a code table corresponding to the reception level of the television receiver 2. The code is composed of 3 bits, and each code excluding the code 000 and the code 111 is assigned to D1 to D5.

FIG. 2 shows an embodiment of the means for electrically reading the reception level code according to the present invention. 301 and 3 in Fig. 2
02, 303 and 304 are pull-up resistors. D terminal 201-2
A, 2B, and 2C are terminals for outputting a reception level code from the reception level code generation block 210. 1A, 1 of D terminal 105
B and 1C are terminals for inputting a reception level code input via the reception level code signal line c, and are connected to the input ports of the CPU 108. Receive level code generation block 210
Here, as an example, a reception level code 010 indicating that the reception level of the television receiver 2 is D2,
Ground level to 2A and 2C, Vcc via pull-up resistor
It is configured to output by connecting the level to 2B.

With the above configuration, the CPU 108 of the digital broadcast tuner 1 transmits the reception level code from the reception level code generation block 210 of the television receiver 2 to the D terminal 201.
2A, 2B, 2C from the CPU 10 via the reception level code signal line c in the D terminal cable m and the 1A, 1B, 1C of the D terminal 105.
Eight input ports enable reading, and an analog component video signal in a video format corresponding to the reception level of the television receiver 2 can be output.

For example, when the reception level code generation block 210 as shown in FIG. 2 is not provided on the television receiver 2 side, the D terminals 201 2A, 2B, and 2C are open, and the D Input ports connected to 1A, 1B, 1C of terminal 105 are pull-up resistors 302, 303, 30
4, the CPU 108 reads the reception level code as 111, and the television receiver 2 is not provided with the reception level code generation block 210 according to the reception level code allocation rule described above. Since the determination can be made, it is possible to prevent an analog component video signal of a video format that does not conform to the reception level of the television receiver 2 from being transmitted.

[0047]

As described above, according to the digital broadcast receiving system of the present invention, the digital broadcast tuner can automatically recognize the reception level of the television receiver, and the initial setting of the user at the time of installation or replacement of equipment. The complexity of the operation can be omitted, and a screen display defect due to a mismatch between the video format and the reception level can be avoided.

[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 diagram showing an example of a circuit for realizing a reception level code reading unit according to the second embodiment of the present invention;

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

FIG. 4 is a block diagram of a video signal transmission system of a conventional digital broadcast receiving system.

[Explanation of symbols]

 210 Receive level code generation block 301, 302, 303, 304 Pull-up resistor c Receive level code signal line

Claims (3)

[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 television receiver having a function of receiving, a mode from D1 to D5 indicating a range of a video format of a digital broadcast receivable by the television receiver is set to the digital broadcast. A tuner having means electrically readable from the television receiver;
The digital broadcast tuner reads which of the D1 to D5 modes the television receiver corresponds to by the electrically readable means, and the analog component video signal adapted to the read mode. And a digital broadcast receiving system. 2. The digital broadcast tuner according to claim 1, wherein said digital broadcast tuner includes an electronically readable means.
A code corresponding to the mode from D1 to D5 is output from a terminal, and a CPU for control in the digital broadcast tuner transmits the code via a D terminal cable connected to a D terminal of the television receiver. The digital broadcast receiving system according to claim 1, wherein the digital broadcast is read. 3. When all bits are 0 or 1 as a code corresponding to the modes from D1 to D5, a means for allowing the digital broadcast tuner to electrically read the D terminal of the television receiver is provided. 3. A digital device according to claim 2, wherein a code that can be determined not to be assigned is assigned, and all terminals to which the code of the D terminal of the digital broadcast tuner is input are pulled up or pulled down. Broadcast receiving system.