KR100219152B1 - Automatic tuning system in voltage synthesize for improving channel memory - Google Patents

Abstract

The present invention is a V / S method for improving the channel memory that can be stored in the memory by selecting the optimal channel among the redundant channels generated in each band switching area when performing the automatic tuning function in the voltage synthesis (V / S) tuning system Relates to an automatic tuning system. The automatic tuning system of the present invention is configured to divide each band switching region into two parts so as not to overlap the reception frequency range of each band, and to generate and tune a pulse width modulated signal based on the reception frequency range. Accordingly, the present invention provides an effect of improving the memory efficiency by storing the tuning data without the redundant channel in the memory in the V / S automatic tuning system.

Description

Voltage Synthesis Automatic Tuning System for Channel Memory Improvement

An object of the present invention is to automatically tune the V / S method to improve the channel memory so that only the optimal channel data can be stored without the redundant channel in the memory when the auto tuning is performed in the voltage synthesis (V / S) tuning system. In providing a system.

The present invention relates to a tuning system of the V / S method applied to a VTR with a built-in television receiver or tuner, in particular, a channel that can store only the optimal channel data without overlapping channels in the memory for storing channel data during automatic tuning The present invention relates to a V / S automatic tuning system for memory improvement.

A TV tuner used for a television receiver, a VTR having a television reception function, and the like tunes a broadcast signal of a desired channel among a plurality of broadcast signals received through an antenna, and 45.75 MHz for video of the broadcast signal and 41.25 MHz for audio. Convert the frequency to an intermediate frequency signal of. On the other hand, the tuner is divided into a potentiometer preset method, a voltage synthesis (V / S) method, and a frequency synthesis method according to the supply mode of the band switching voltage and the tuning voltage. The V / S tuning system converts the tuning voltage and band switching voltage of 2 to 25V into digital signals and stores them in the IC memory for each channel button. Then, when the desired channel is set for each channel button, when the channel button is pressed, the digital signal corresponding to the channel button is converted into a tuning voltage and a band switching voltage and applied to the tuner. In the V / S type tuning system, there is an Auto Tuning function, which automatically searches for and presets the TV signal coming from the antenna.The channel number of the TV signal received from the area is sequentially received for each channel button. You can also preset automatically from a small number. That is, in the V / S tuning system, during tuning, the tuning voltage of each band is gradually stored from the minimum value to the maximum value in steps of the tuning voltage value of the channel in which the received signal is stored in the memory. In Europe, since a station code is sent together, the tuning system stores a tuning voltage value of a channel where a station code is detected in a memory.

FIG. 1 is a diagram illustrating characteristics between a tuning voltage and a reception frequency of each frequency band in a conventional V / S automatic tuning system. Here, for the receiving channels VHF-LOW, VHF-HIGH, and UHF, the horizontal axis represents the reception frequency f, and the vertical axis represents the tuning voltage V. Referring to FIG. 1, the same broadcast signal is tuned in the low band of the VHF, the high band, and the adjacent reception frequency band of the UHF. That is, the same broadcast signal is tuned in spite of different tuning voltages in the edge region of each band (see hatched portion). Thus, the tuning voltage is converted into a digital signal of a certain bit and stored in the memory, and the digital signal is read out and then converted into an analog tuning voltage for tuning.

However, when the automatic tuning function is performed in the conventional V / S tuning system as described above, the same broadcast signal channel is tuned to different tuning voltages, so that there is a problem that the memory is duplicated and stored in the memory. Thus, the present invention proposes a V / S type automatic tuning system in which channel data is stored in a memory without a redundant channel.

1 is a view showing a characteristic between a tuning voltage and a receiving frequency of each frequency band in an automatic tuning system of a conventional voltage synthesis method;

Figure 2 is a block diagram showing a preferred embodiment of the automatic tuning system of the voltage synthesis method according to the present invention,

3 is a detailed view showing a tuning voltage generator of the system of FIG.

4 is a view showing a characteristic between a tuning voltage and a reception frequency for each frequency band of the present invention.

* Explanation of symbols for main parts of the drawings

21 control unit 22 tuning voltage generator

23 tuner 24 image demodulation unit

25: memory

Accordingly, the V / S type automatic tuning system for improving the channel memory of the present invention is a voltage synthesis (V / S) type automatic tuning system, in which each band switching region is divided into two parts so that the reception frequency range of each band does not overlap. A control unit for generating a pulse width modulated signal for channel tuning based on the received frequency range, a tuning voltage generator for receiving a pulse width modulated signal and a tuning reference voltage of the control unit and increasing the tuning voltage step by step; And a tuner for tuning a channel having a frequency corresponding to the tuning voltage applied from the tuning voltage generator, and a memory for storing the tuning voltage when the broadcast signal is tuned by the tuner for each band.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing an automatic tuning system of the V / S method to which the present invention is applied. The automatic tuning system shown in FIG. 2 includes a control unit 21 for generating a pulse width modulation (PWM) signal for band selection and channel tuning of the band, and a tuning reference voltage and a pulse width modulation (PWM) signal. And a tuning voltage generator 22 that receives the input and generates a tuning voltage. A detailed configuration for the following will be described later with reference to FIG. 3. Tuning Voltage Generator 22 The tuning voltage generator 22 is connected to a tuner 23 for tuning a broadcast signal of a channel corresponding to a tuning voltage among broadcast signals received through an antenna. The tuner 23 outputs a video signal to a video signal processor (not shown) at the rear end by demodulating the selected broadcast signal, and detects an AFT (Automatic Fine Tuning) signal of the broadcast signal and outputs it to the controller 21. The image demodulator 24 is connected. The controller 21 is also connected to a memory 25 that stores data for channel tuning for each band. Here, the memory 25 uses a non-volatile memory (NV-RAM).

3 is a detailed view illustrating the tuning voltage generator 22 of the FIG. 2 system. The tuning voltage generator 22 shown in FIG. 3 receives a pulse width modulated (PWM) signal as a base and receives a tuning reference voltage as a collector to " ON / OFF " according to the pulse width modulated (PWM) signal. And a multi-stage integrator 221 in which an integrator consisting of a resistor and a capacitor is connected in multiple stages, and a transistor Q for outputting a tuning reference voltage in a "off" state.

The operation of the tuning system of the V / S method according to the present invention configured as described above will be described in more detail with reference to FIG. 4.

FIG. 4 is a diagram illustrating a characteristic between a tuning voltage and a reception frequency of each frequency band of the present invention. By dividing the overlapping portions of the edge regions of each band, the frequency range of the reception channel can be defined and tuned to the frequency. It also redefines the variable range of the tuning voltage. The "VHF-LOW" band defines the "B" section as the receiving frequency range in the existing "A" section, and the "VHF-HIGH" band defines the "D" section as the receiving frequency range in the existing "C" section and the "UHF "Band" defines the "H" section as the reception frequency range in the existing "G" section. The tuning voltage has a characteristic of continuously varying within a predetermined range. If the tuning voltage is generally 0 to 33V, the tuning voltage is continuously changed corresponding to the hatched portion of each band in FIG.

The control unit 21 of FIG. 1 is a pulse width modulation (PWM) for varying the tuning voltage so that the local oscillation frequency of the tuner 23 is changed in the reception frequency range for each band defined as shown in FIG. 4 at the time of receiving V / S automatic tuning. Generates a signal. That is, the control unit 21 generates a pulse width modulated signal having a duty between 0 and B / A when the band of the reception channel is VHF-LOW, and E / C to (E + D) when VHF-HIGH. In the case of) / C and UHF, a pulse width modulated signal having a duty of F / G to (F + H) / G is generated. The tuning voltage generator 22 generates a tuning voltage by the tuning reference voltage and the pulse width modulation (PWM) signal applied from the control unit 21. That is, the transistor Q of the tuning voltage generator 22 is in the "ON" state in a section in which the pulse width modulation (PWM) signal input to the base is at the "High" level, and is "Low". In the section at the ")" level, the state is turned "OFF". In the "ON" state, the transistor Q outputs a low potential signal of "0V" by grounding the tuning reference voltage input to the collector through the emitter. In contrast, in the " off " state, the transistor Q outputs a tuning reference voltage input to the collector. The output of the transistor Q is sequentially integrated through the multistage integrator 221, and a tuning voltage that is continuously varied is applied to the tuner 23. The tuner 23 tunes the broadcast signal according to the tuning voltage applied among the broadcast signals received through the antenna and outputs the tuned signal to the image demodulator 24. The image demodulator 24 performs intermediate frequency processing on the output signal of the tuner 23, detects an AFT signal of the broadcast signal, and outputs the AFT signal to the controller 21. The image demodulator 24 also demodulates the tuned broadcast signal, and outputs the video signal VIDEO to a rear image signal processor (not shown) so that it can be displayed on the screen. The controller 21 calculates data for channel tuning from the AFT signal applied from the image demodulator 24 and stores the data for channel tuning in the memory 25. Here, the controller 21 adjusts the duty of the pulse width modulation (PWM) signal for channel tuning so that the redundant channel is not tuned.

As described above, the present invention relates to an automatic tuning system of the V / S method for improving the channel memory, and when the automatic tuning function is performed in the V / S type tuning system, the channel tuned in the band switching region is duplicated and stored in the memory. Compared to the related art, by dividing the reception frequency part of the redundant channel into two parts, the duty of the pulse width modulated signal for generating the tuning voltage is adjusted to select and store only the optimal channel among the overlapped channels.

Claims (3)

In a voltage synthesis (V / S) type automatic tuning system, each band switching region is divided into two parts, A control unit for determining a reception frequency range of each band so as not to overlap and generating a pulse width modulated signal for channel tuning based on the reception frequency range; A tuning voltage generator which receives the pulse width modulation signal and the tuning reference voltage of the controller and increases the tuning voltage in steps and outputs the tuning voltage; A tuner for tuning a channel having a frequency corresponding to a tuning voltage applied from the tuning voltage generator; And Auto tuning system of the V / S method for improving the channel memory including a memory for storing the tuning voltage when tuning the broadcast signal in the tuner for each band. The method of claim 1, wherein the tuning voltage generator A transistor configured to be in an " ON / OFF " state according to the pulse width modulation signal of the controller to switch the tuning reference voltage; And And a multi-stage integrator for generating a tuning voltage by integrating the tuning reference voltage output through the transistor step by step. The channel memory of claim 2, wherein the control unit bisects an overlapping frequency region between bands for channel tuning, and adjusts the duty of the pulse width modulation signal to vary the minimum and maximum values of the tuning voltage. V / S automatic tuning system for improvement.