JPH07274153A - Channel selection device - Google Patents

Abstract

PURPOSE:To permit a receiver to recieve a signal in the output channel of CATV BOX when CATV.BOX is connected to VTR and TV. CONSTITUTION:A station selection device is provided with a cable box 1 receiving a CATV broadcasting signal and converting it into the signal of a prescribed frequency and a video tape recorder 7 provided with a tuner 10 receiving the signal of the frequency of the prescribed channel from the cable box 1. The video recorder 7 is provided with a microcomputer 9. The microcomputer 9 receives a synchronizing signal obtained from a signal from the tuner 10, judges the prescribed channel frequency and controls the tuner 10 so that it is turned with the prescribed channel frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel selection device used for a video tape recorder (VTR), a TV (television) receiver or the like to which a CATV / BOX (cable box) is connected.

[0002]

2. Description of the Related Art CATV (cable television) broadcasting has become widespread in the United States. This CATV broadcast
As shown in FIG. 3, it is normally received by the CATV / BOX. The CATV signal is the channel selection circuit 2 of the CATV / BOX1.
First, the desired channel is selected, and then the tuning circuit 2
The signal selected at is descrambled by the descramble circuit 3, and the descrambled signal is RF.
The signal is converted into an RF signal by the conversion circuit 4 and converted into one channel (any one of 2CH to 7CH in the US, 3CH in the figure), and V
It is supplied to a receiving device such as TR5.

Then, the user views the CATV channel selected by the CATV / BOX by selecting the VTR 5 as the channel (3CH) output from the CATV / BOX 1 by the remote control transmitter 6 or the like. You can do it.

[0004]

By the way, CATV
Channels converted by BOX are CATV / B
This varies depending on the OX manufacturer and model. Therefore, the user needs to know the channel output from the CATV / BOX from the instruction manual or the like, and then control the receiving device such as the VTR to tune to it.

Therefore, the present invention aims to solve such problems.

[0006]

SUMMARY OF THE INVENTION The present invention is a cable box for receiving a CATV broadcast signal and converting it to a signal of a predetermined channel frequency, and a signal of the frequency of the predetermined channel from the cable box. A video tape recorder provided with a tuner, wherein the video tape recorder is provided with a microcomputer, the microcomputer receiving a synchronization signal obtained from a signal from the tuner, and receiving the predetermined channel frequency. It is configured to determine and control the tuner to tune to the predetermined channel frequency.

[0007]

The VTR automatically detects the channel frequency of the RF signal output from the cable box and matches the tuning frequency of the tuner of the video tape recorder with it.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a video tape recorder embodying the present invention and a CATV / BOX (cable box) connected thereto, and FIG. 2 shows an operation flowchart thereof. The same parts as those in FIG. 3 are designated by the same reference numerals.

In FIG. 1, CATV broadcasting is first performed by CA.
A desired channel is selected by the channel selection circuit 2 of the TV / BOX 1, then the signal selected by the channel selection circuit 2 is descrambled by the descramble circuit 3, and the descrambled signal is converted by the RF conversion circuit 4. Converted to RF signal with one channel (2CH in the US ~
It is converted to VTR7
Is supplied to.

Use of CATV / BOX for VTR7
A user setting switch 8 that is set when not in use is provided. In other words, when using CATV / BOX,
This switch 8 is set to the USE side (position between terminals a and b), and when not in use, this switch 8 is NOT USE
Side (position on the side of terminals bc). The output of the switch 8 is input to the microcomputer 9. 1
Reference numeral 0 denotes a tuner for receiving the RF output of the RF converter 4, and a video signal obtained from this tuner is supplied to a sync separation circuit 11, where a sync signal (horizontal sync signal) is extracted and supplied to a microcomputer. It Also, the video signal from the tuner is supplied to the video signal processing circuit.

The next operation will be described with reference to the flowchart of FIG.

When the CATV is used, the switch 8 is USE
Is set to the position (the position shown in the figure), the microcomputer 9 receives the high level signal voltage and
It is determined that the mode is the TV use mode (S1). Step 1
If it is determined to be NOT USE in (S1), CA
No operation related to TV signal selection is performed.

When it is determined that the mode is the CATV use mode, the microcomputer 9 looks at the sync separation output from the sync separation circuit and determines whether a predetermined number of horizontal sync signals exist within a predetermined time (S2). ).

When it is determined in step 2 that a predetermined number of horizontal synchronizing signals are present within a predetermined time, it is determined that the station is stationed, and the channel currently being received by the tuner is CAT.
It is determined that the output channel is a V-BOX, the frequency information of this channel is stored in the RAM of the microcomputer 9, and thereafter the tuner 10 causes the microcomputer 9 to tune to the channel frequency stored in this RAM. Controlled by.

On the other hand, when it is determined in step 2 that the horizontal synchronizing signal does not exist in the predetermined number within the predetermined time, it is determined that there is no station, and the tuning voltage is increased in order to increase the reception channel. Assuming that the channel up operation starts from channel 2, for example, channel 2, channel 3, channel 4, channel 5, channel 6 and channel 7 are performed in this order, and step 2
When a local channel is detected, the channel is stored in the RAM of the microcomputer by the above operation.

As described above, the channel number stored in the RAM of the microcomputer 9 can be changed by the switch 8 to the NOT USE side, or
It is held until the AC power supply of VTR7 is cut off.

Further, in the above configuration, it is determined whether the station is a station or not depending on whether or not there are a predetermined number of horizontal synchronization signals. However, when the switch is on the CATV receiving side and it is determined that the station is present, the automatic If the main power source of the VTR 7 is turned on, the CATV broadcast can be watched only by operating the CATV / BOX 1.

[0018]

As described above, according to the present invention, the CATV
When the BOX is connected to a receiver such as a VTR or TV, C
Since the receiver automatically tunes to the output channel of the ATV / BOX, the usability for the user is greatly improved.

Further, since the microcomputer makes a decision as to whether or not there is a certain number of horizontal synchronizing signals, it determines whether or not there is a station. If the power is turned on, the CA can be operated by simply operating the CATV / BOX
You can watch TV broadcasts.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a VTR embodying the present invention and a CATV / BOX connected thereto.

FIG. 2 is a diagram showing a flowchart for explaining the operation of the circuit block operation of FIG.

FIG. 3 is a conventional VTR and a CATV connected to it.
It is a block diagram of a BOX.

[Explanation of symbols]

 1 Cable Box 2 Channel Selection Circuit 3 Scramble Descramble Circuit 4 RF Convert 7 Video Tape Recorder 8 User Setting Switch 9 Microcomputer 10 Tuner 11 Sync Separation Circuit

Claims (4)

[Claims] 1. A cable box for receiving a CATV broadcast signal and converting it to a signal of a predetermined channel frequency,
A receiver provided with a tuner for receiving a signal of the frequency of the predetermined channel from the cable box, the receiver tunes the tuner to the predetermined channel frequency by observing an output from the tuner. A channel selection device having a control means for controlling to perform. 2. The receiver according to claim 1, comprising a microcomputer as the control means, the microcomputer receiving a synchronization signal obtained from a signal from the tuner to determine the predetermined channel frequency, A tuning device adapted to control the tuner so as to tune to the predetermined channel frequency. 3. The tuning device according to claim 2, wherein the receiver is a video tape recorder. 4. The tuning device according to claim 2, wherein the receiver is a television receiver.