KR0163486B1 - Synchronization method for channel selecting in vcr - Google Patents

Abstract

The present invention relates to a means for precisely performing electronic tuning operations in TV receivers or VSI systems capable of receiving TV broadcasts. In the related art, the present invention relates to a user when the system is placed in a weak broadcast reception field or a lot of extraneous noise. There was a problem that the system did not make the correct channel selection such as channel selection other than the selected channel.

According to the present invention, a synchronization setting unit 2 is provided between the synchronization separation unit and the microprocessor 32 on the video block 39 side, and the memory 42 or the like is provided with a tuner and the like. When the normal sync level of the IFF signals provided from the IFF units 34 and 35 is 1, a synchronization setting processing program 1 for processing a process of setting the number of synchronization signals variably in accordance with the reception electric field is mounted. The present invention provides a synchronization setting processing method for channel precision tuning in a VSI or the like that is processed.

Description

Synchronization setting processing method for channel precision tuning in VSI

1 is a diagram illustrating a system circuit block of a general video cassette recorder (VCR).

2 is a schematic block diagram of the main portion of the system circuit according to the present invention.

3 is an embodiment of a synchronization setting processing program according to the present invention.

* Explanation of symbols for main parts of the drawings

1: Synchronization setting processing program 2: Synchronization setting unit

The present invention relates to a TV receiver or a VSI system having a broadcast receiving function. In particular, in such a system, when a channel is tuned using a microprocessor and an automatic tuning tuner, a broadcast signal is changed due to a weak electric field. In this case, the phenomenon in which a predetermined channel is not properly received can be actively excluded.

A processing apparatus for receiving various TV broadcast signals and outputting video and audio signals is known to TV receiver systems. The TV receiver includes a timer microcomputer for selecting a channel using a key provided in a key unit on a remote control transmitter or a set side. Electronic tuning tuners are being used with processors or system microprocessors.

In addition, the TV receiver system handles various video / audio signals to record broadcast signals, record another external signal, or record or play another external signal. It is used to record broadcasting programs required by VSI by embedding an automatic tuning tuner such as a receiver system.

An example of such a VSIAL system is shown in FIG.

Here, a tuner 34 which receives a regular broadcast signal from the antenna 33 of the VSI system and performs channel tuning, an IF circuit 35 for intermediate frequency processing of the tuning signal provided by the tuner 34, and A microprocessor 32 for controlling the sial system, an OSD circuit 41 for generating an OSD screen, a memory 42 for storing channel contents of various reserved recordings necessary for the VSI system control, Key portion 31 for key operation, deck 36 for recording / reproducing deck operation, servo circuit 37 for controlling a drive motor on the deck 36 side, RF converter 38, video signal processing The video block 39 and the monitor or TV receiver unit 40 for outputting the video signal provided from the video block are constituted.

In such a conventional system, when the microtuning is tuned, the microprocessor 32 sends a pulse width modulation (PWM) signal to the tuner 34 to apply the voltage to the tuner 34 through an integrated circuit. The tuner 34 tunes the channel by converting the tuning frequency according to the tuning voltage applied.

In this way, when the channel is tuned, the video block 39 separates the sync, and the microprocessor 32 calculates the number of sync pulses to determine whether the tuned channel is the correct channel.

And, in such a conventional system, when the broadcast reception environment of such a system is a strong electric field area or there is no signal interference such as external noise, the system microprocessor 32 can accurately determine the number of synchronization and perform the tuning work correctly.

However, in such a system, when the broadcasting reception environment is weak in an electric field or there is a lot of extraneous noise, the unnecessary channel is caught by skipping a predetermined channel due to the variation in the number of synchronizations checked by the microprocessor 32. When the unnecessary channel is caught, it has been a problem because it takes time to find the right channel.

An object of the present invention is to allow the microprocessor to check the reception level of the intermediate frequency signal in the system to adjust the number of synchronization signals according to the signal level to suppress the interference channel memory in order to improve the above problems. To tune in the correct channel.

According to the present invention, a system microprocessor, a memory, or the like, which is mounted here, checks an input level of an intermediate frequency and sets the number of synchronous frequencies according to the result of checking the input level. The synchronization setting processing method for channel precision tuning is characterized by a VSI or the like of a method of providing and processing a synchronization setting processing program which is composed of processing steps.

Hereinafter, more specific features of the present invention will be understood by describing the same in detail with the accompanying drawings.

That is, FIG. 2 shows a block diagram of the main part excerpt circuit in the system according to the present invention.

Here, the microprocessor 32 and the video block 39 side in a circuit including the system microprocessor 32, the memory 42, the tuner and eye parts 34 and 35, the video block 39 including the synchronous separation part, and the like. Between the synchronization separation units of the synchronization setting unit 2 which operates according to a signal for controlling the microprocessor 32 to set the number of synchronization in accordance with the IF input level from the tuner and the IF unit 34,35 is provided. It is done.

In the system memory 42, the synchronization setting processing program 1 of the third embodiment is mounted.

The synchronization setting processing program 1 checks IF = 1 application when the number of normal levels of the IF frequency from the start step is 1 (step 11). The process is carried out in a range (step 15), and if IF is not 1, IF 1 is checked (step 12).

In the case of IF 1 in step 12, the number of synchronization signals is set in the range of 30 to 34 (step 16). If not, the application of IF 1 is checked (step 13).

In step 13, if IF 1, the number of synchronization signals is set in the range of 26 to 38 (step 17). If not, it is checked whether IF = 0 (step 14).

In step 14, if IF = 0, it is reported as a no-signal input state, and the screen is maintained as a blue back screen (step 18). If IF = 0, a series of processes are performed.

In the present invention as described above with reference to FIGS. 2 and 3, when the electric field strength of the broadcast signal received from the antenna is weak, etc., the number of synchronization signals having a constant I-F signal level output from the tuner and I-F units 34 and 35 Since the microprocessor 32 is not shaken to maintain the tuner 34, it is difficult to find the synchronization point of the tune channel.

In the present invention, however, the IF level output from the IF part 35 is regarded as a normal level of 1 having the number of synchronization signals in the range of 28 to 36, and the synchronization number is set based on this, so that the field strength is weak. Alternatively, the number of synchronous pulses can be set according to local characteristics such as a place where there is a lot of extraneous noise, and the synchronous change can be made so that the microprocessor 32 can receive a more accurate channel when tuning the tuner 34. This is possible.

The above operation is performed by the system microprocessor 32 together with the synchronization setting processing program 1 of FIG. 3, in which case IF = 0 when the number of normal levels of the IF frequency in the system is 1; If 1 is checked, if it is 1, the number of synchronization settings is processed in the range of 28 to 36, if not 1, IF 1, IF 1, IF = 0, etc. It will be done.

The present invention provides accurate tuning of a channel to be tuned by automatically or manually setting a synchronization signal in a weak electric field or a lot of extraneous noise in a broadcast receiving environment or a VSI system capable of receiving a TV broadcast. It is possible to work, and even if a predetermined channel is tuned as in the prior art, other channels are caught, so that unnecessary work such as continuing the tuning work until a correct channel is available can be made.

Claims (1)

Means for performing fully automatic shipbuilding processing in a system including a system microprocessor (32), a memory (42), a tuner and IF parts (34, 35), a video block (39) including a synchronization separator, and the like. A synchronization setting unit 2 is provided between the synchronization separating unit on the 39 side and the microprocessor 32, and the memory 42 or the like is provided with the normality of the IFT signals provided from the tuner and the IFA units 34 and 35. When the synchronization level is 1, the channel precision tuning is performed by VSI, etc., which is equipped with a synchronization setting processing program 1 which carries out a processing operation for setting the number of synchronization signals variably according to the reception electric field state. Synchronization setting processing method.