KR100249220B1 - Apparatus of adjusting intermediate frequency vco in tv and method for its adjustment - Google Patents

Abstract

The present invention relates to an apparatus and a method for automatically adjusting a medium frequency VCO (Voltage Controlled Oscillator) in a TV, and to select a specific channel according to a control signal among various channel broadcast signals input from an antenna, and to select an intermediate frequency signal of a selected channel. By adjusting the intermediate frequency resonance variable coil unit and the capacitor switching unit controlled by the microcomputer and resonating according to the variable capacitor value, the adjustment bit value for obtaining this resonance value is stored in the memory (EEPROM). When the intermediate frequency signal of the selected channel is tuned, the automatic adjustment bit value stored in the memory is output to determine the capacitor value so that the automatic adjustment is possible. Will be.

Description

TV's VCO automatic adjustment device and method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TV, and in particular, in the service mode of the TV, an intermediate frequency (hereinafter, referred to as IF) voltage control oscillation (hereinafter, referred to as VCO: Voltage) is performed by an adjustment bit value stored in a memory by simply operating a remote controller key. The present invention relates to a TV IF VCO automatic control device and a method for automatically adjusting a controlled oscillator.

In general, to adjust the IF VCO, by varying the value of the variable coil for IF resonance, it is possible to find the desired IF value for accurate VCO adjustment.

1 is a block diagram of an IF VCO adjusting device according to the prior art, a tuner unit 10 for tuning and outputting a desired signal and an IF resonance variable nose for adjusting an IF signal according to a variable value of a coil. A part 30 and a synthesizer 40 for synthesizing an IF signal at the right tuning point to produce a composite video baseband signal (CVBS) output, and the output of the synthesizer 40 is image processed. And an image / deflection processor 60 for deflection adjustment, and a screen display unit (CRT) 70 for finally outputting a signal, and an IF VCO adjustment signal generator for generating an IF signal for adjustment for accurate VCO adjustment. 20, and an IF signal monitor 50 for displaying the output of the synthesizer for VCO adjustment.

Referring to the IF VCO adjusting method according to FIG. The IF signal of the tuner unit 10 in synchronization with the IF signal is input to the synthesis unit 40.

The synthesizer 40 displays the input signal waveform on the IF monitor 50, and the output waveform of the displayed synthesizer 40 changes according to the adjustment value of the IF coil variable 30 for the display. By varying the coil with the adjustment rod, adjust the pin to find the exact value of the desired IF signal.

2 is a block diagram showing an actual circuit of an IF VCO adjusting device according to the prior art, including an IC-chip (TDA83xx) 90 including a synthesizer 40 and an image / deflection processor 60, and the IC-. In order to control the chip 90 and the tuner unit 10, the microcomputer 80 is connected to the I ² C bus line, and the other configurations are the same as those of FIG.

Referring to the IF VCO adjustment method according to the prior art configured as shown in Figure 2, the tuner unit 10 selects a specific channel according to the control information through the I ² C bus line of the microcomputer (80).

At this time, the IF VCO adjustment signal generation unit 20 generates an IF signal for adjustment, tunes the IF signal passing through the tuner unit 10, and applies it to the synthesis unit 40 in the IC chip 90.

The IF signal monitor unit 50 displays the output waveform of the synthesis unit 40 and adjusts the variable coil of the IF resonance variable coil unit 30 to find the resonance frequency value.

At this time, as the AFT (hereinafter, AFT: Automatic Frequency Tuning) signal is applied to the IC chip 90 through the I ² C bus line in the microcomputer 80, the resonance IF signal adjusted to the synthesis unit 40 is The AFT signal is precisely adjusted through the IF resonance coil part 30 so that the AFT signal is adjusted at the right tuning point.

In order to adjust the IF VCO according to the prior art, not only a signal generator and an IF signal monitor for adjusting the IF VCO are required, but also a separate jig for detecting a signal supply and a signal output is required for the synthesis unit. It takes a lot of time because it needs to adjust the variable coil while judging the signal through.

In addition, in order to adjust the resonant frequency of the capacitor configured in the IC-chip element and the resonant coil connected to the outside, the frequency can be adjusted by varying the coil.

The present invention has been made to solve the above problems, the IF VCO adjustment signal generator, IF signal monitor, as well as a separate jig for sensing the signal supply and output, as well as the adjustment bits stored in the memory The purpose is to automatically adjust the IF VCO by using the value.

1 is a block diagram of an intermediate frequency VCO regulator according to the prior art.

2 is a block diagram showing the actual circuit configuration of the intermediate frequency VCO regulator according to the prior art.

3 is a block diagram of an intermediate frequency VCO automatic adjustment apparatus according to the present invention.

Figure 4 is a flow chart showing an automatic storage method for the intermediate frequency VCO automatic adjustment device of Figure 3 according to the present invention.

Figure 5 is a block diagram showing the actual circuit configuration for the intermediate frequency VCO automatic adjustment apparatus according to the present invention.

6 is a view comparing the AFT voltage waveform of the VS system according to the intermediate VCO adjustment bit value with the intermediate frequency AFT voltage waveform according to the present invention.

7 is a flowchart illustrating an automatic storage method for the intermediate frequency VCO automatic adjustment device of FIG. 5 according to the present invention.

8 is a flowchart illustrating an autotuning method for an intermediate frequency VCO auto-tuning apparatus of FIG. 5 according to the present invention.

* Explanation of symbols for main parts of the drawings

10: Tuner part 30: Variable coil part for intermediate frequency resonance

40: synthesis section 80: microcomputer

90: IC chip (TDA83xx) 100: capacitor switching unit

110: AFT / ID signal detector 120: EEPROM

130: coil part for intermediate frequency resonance

In order to achieve the above object, a feature of the present invention is to switch the capacitors A ₀ A ₁ A ₂ A ₃ A ₄ A ₅ A ₆ to the IF signal of a specific channel by the control signal of the microcomputer in accordance with the VCO adjustment bit value. By resonating with the fixed coil, the VCO adjustment bit value according to the resonance value is input to the microcomputer through the sensing circuit and stored in the memory. In the next IF VCO adjustment, the adjustment bit value stored in the memory for the capacitor adjustment is adjusted. It is possible to automatically adjust the IF VCO by using.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the IF VCO automatic adjustment device according to the present invention will be described in detail.

3 is a block diagram of an IF VCO automatic adjustment device according to the present invention, a tuner unit 10 for tuning a specific channel according to a specific control value, an IF resonance coil unit 130 used for frequency resonance, and , The capacitor switching unit 100 for switching the capacitor required for frequency resonance according to the VCO adjustment bit value according to the output data of the microcomputer 80, the synthesis unit 40 for synthesizing the input signal, and AFT (Automatic Frequency Tuning) AFT and ID detection unit 110 for detecting the signal and ID (Identification) signal and transmitting these signals through the bus line, and EPIROM storing the AFT signal and the ID signal which are the VCO adjustment bit values. Control the tuner unit 10, the EEPROM 120, the AFT ID detector 110, and the capacitor switching unit 100 through an EEPROM: Electronic Erasable Read Only Memory (120) and an I ² C bus line. The CVBS signal which is an output signal of the microcomputer 80 and the synthesizer 40 which has been automatically adjusted An image / deflection processing unit 60 which performs video / deflection processing, and a screen display unit 70 which finally displays a screen.

In addition, the capacitor switching unit 100 switches the capacitor by a microcomputer 80 control signal to create a plurality of capacitors to be used for frequency resonance and a synthesized capacitor value necessary for frequency resonance using the plurality of capacitors. It consists of a number of switches.

On the other hand, the method for automatic adjustment of the intermediate frequency VIO of the present invention, after controlling the switching of the capacitor by outputting the channel information of a specific channel, using the automatic frequency tuning signal and the presence or absence of the intermediate frequency detection signal to determine the adjustment value The automatic storage step of storing in the memory, and when the channel selection is made, the automatic adjustment step of tuning the already set state by performing the switching control for reading the adjustment value stored in the memory to determine the capacitor value.

The automatic storing may include outputting information of a specific channel tuned through the tuner unit 10 and outputting an initial control adjustment value to the capacitor switching unit 100, and an automatic frequency based on the output control adjustment value. Determining whether an AFT signal and an intermediate frequency detection (ID) signal exist; and if the automatic frequency tuning (AFT) signal and an intermediate frequency detection (ID) signal exist, the current control adjustment value is determined. Determining the control adjustment value by repeating the process of determining the presence of the signal by increasing the control adjustment value if not present, and determining whether to store the determined control adjustment value in the memory, and storing it in the memory if desired. Characterized in that it comprises a step, the automatic adjustment step is a channel selection confirmation step of confirming whether the channel by the user selection is selected, A storage data read step of reading control data stored in a memory to tune a frequency according to a corresponding channel when the frequency is selected, and a switching control step of controlling the capacitor switching unit 100 according to the read data; And a corresponding frequency tuning step of tuning a corresponding frequency according to the synthesized value of the switched capacitor.

In the IF VCO automatic storage method according to FIG. 3, the tuner unit 10 tunes a specific channel by the microcomputer 80, and inputs the IF signal of the tuned channel to the synthesis unit 40. 100 performs switching according to the adjustment bit value of the microcomputer 80 to obtain a specific capacitor value A ₀ A ₁ A ₂ A ₃ A ₄ A ₅ A ₆ .

At this time, the resonance is caused by the fixed coil value and the variable capacitor value of the IF resonance coil unit 130, the IF signal is adjusted by the LC resonance value, and then the CVBS signal is output after passing through the synthesis unit 40. The image is then output to the screen display unit 70 via the image / deflection processing unit 60.

At the same time, the bit value of the AFT signal ID signal, which is the VCO adjustment bit value (A ₀ A ₁ A ₂ A ₃ A ₄ A ₅ A ₆ ) for IF signal adjustment, is detected by the AFT / ID signal detector 110 and is determined to be I ^2. It is stored in the EEPROM 120 through the C bus line.

Therefore, the next time the same IF signal requiring IF VCO adjustment is input, the IF VCO adjustment is automatically made by the stored VCO adjustment bit value.

4 is a flowchart illustrating a VCO automatic storage method according to the present invention. When the microcomputer 8 gives the tuner 10 a control value for a specific channel, the tuner 10 synthesizes an IF signal for a specific channel. The capacitor switching unit 100 receives all capacitors from the microcomputer 80 by inputting 'A ₀ A ₁ A ₂ A ₃ A ₄ A ₅ A ₆ = 0000000' as the VCO adjustment bit value. By turning off, the capacitor capacitance value becomes "0".

The CVBS signal output from the combining unit 40 passes through the AFT / ID detector 110 according to the capacitor capacitance value and detects the AFT / ID signal value and gives it to the microcomputer 80.

The microcomputer 80 checks whether the AFT signal value is YES. If the AFT signal value is YES, the microcomputer 80 checks whether the next ID signal value is YES.

At this time, if the AFT signal or ID signal value is NO, the VCO adjustment bit value is raised to '1' to make 'A ₀ A ₁ A ₂ A ₃ A ₄ A ₅ A ₆ = 0000001' and supply it to the capacitor switching unit 100 again. Done.

The output of the combining section 40 is supplied to the AFT / ID detecting section 110 again, and the microcomputer 80 continues to A ₀ A ₁ A ₂ A ₃ A ₄ A ₅ until the AFT and ID signal values become YES. Increase the value of A ₆ by "1".

Finally, when all of the AFT and ID signal values are YES, it is checked whether or not the corresponding VCO adjustment bit value is to be stored in the EEPROM 120, and then the flow is completed in the EEPROM 120 to terminate the flowchart for automatic adjustment.

5 is a block diagram showing the actual circuit configuration of the intermediate frequency VCO automatic adjustment device according to the present invention, by using the I ² C bus line to export the control information for a specific channel to the tuner unit 10, IC- The capacitor switching unit 100 of the chip (TDA83xx) 90 is controlled, the IFA, which is the intermediate frequency ID signal, and the AFA and AFB signals, which are AFT signals for adjusting the right tuning point, are read, and the VCO adjustment bit value is set to the EEPROM (120). Is connected to the microcomputer 80 with I ² C bus line, and receives the control information about the channel from the microcomputer 80 and transmits the IF signal of the desired channel to the IC-chip. The tuner unit 10 to be supplied to the synthesis unit 40, the IF resonant coil unit 130 to form a coil value for constructing the LC resonant circuit, and the VCO adjustment bit value from the microcomputer 80 are stored. , EEPROM (memory to allow the microcomputer 80 to recognize the stored control adjustment information) 120 and the capacitor switching unit 100 for changing the capacitor value according to the VCO adjustment bit value of the microcomputer 80 to increase or decrease the resonance frequency, the IF signal from the tuner unit 10 and the resonance frequency signal of the LC resonance circuit. The synthesizer 40 which outputs the CVBS signal by the signal, the AFT / ID signal detector 110 which detects the IF signal and the AFT signal, and sends them to the microcomputer. And an image / deflection processing unit 60 for processing and outputting the screen, and a screen display unit 70 for outputting the screen.

In addition, the capacitor switching unit 100 is a plurality of capacitors to be used for frequency resonance, and using the plurality of capacitors to switch the capacitors by the microcomputer 80 control signal to create a composite capacitor value required for frequency resonance It consists of a number of switches.

The operation process of the IF VCO automatic control device configured as described above is described in detail as follows.

The microcomputer 80 outputs control information about a specific channel to the tuner unit 10 to apply the IF signal of the channel selected from the high frequency signals received from the antenna to the synthesis unit 40 and at the same time adjusts the six VCO adjustment bit value (A ₀ A ₁ A ₂ A ₃ A ₄ A ₅ A ₆ ) consisting of bits is applied to the capacitor switching unit 100 in the IC chip (TDA83xx) 90 so as to provide an IF resonance coil unit 130. By coordinating with the coils of ()), resonance occurs with the IF signal applied from the tuner unit 10.

The six bits of the VCO adjustment bit value can be changed from 0 to 127 (0000000 to 1111111), and the capacitance value when the VCO adjustment bit value is increased by 128 is about 3.8 pF.

에 의하여 캐패시턴스가 변하게 되므로 주파수를 조정할 수 있다.When the VCO adjustment bit value changes

The capacitance is changed by, so that the frequency can be adjusted.

The AFT / ID signal detector 110 detects an AFT signal (AFA, AFB signal) and an ID signal (IFI signal), which are VCO adjustment bit values for the IF resonance, and sends them to the microcomputer 80.

The VCO adjustment bit value input to the microcomputer 80 is stored in the EEPROM 120.

The synthesizer 40 outputs the CVBS signal by the IF signal from the tuner unit 10 and the resonant frequency signal by LC resonance and passes through the image / deflection processor 60 to display the OSD (On Screen Display) of the microcomputer. Signal is displayed on the screen display unit 70.

FIG. 6 compares the AFT signal waveform of the VS (Voltage Synthesizer) system with the IF VCO adjustment bit value and the voltage waveforms of the ID signal and the AFT signal according to the present invention. high), if there is no IF signal, the signal is operated as low (low). Therefore, only when the IF signal passing through the tuner unit 10 is input to the synthesis unit 40, the high operation is performed.

In addition, as an AFT signal output from the microcomputer 80, an AFA signal used as a response of the AFT signal is operated at a high frequency at the center frequency of the IF signal when the IF signal is input to the synthesis unit 40. AFB, which is an AFT signal, operates high in a frequency region lower than the center frequency of the response signal (AFA signal), and operates low in a high frequency region, whereby it can be adjusted to a positive tuning point.

At this time, the frequency band where the AFA signal is high is about -256 kHz, which is wider than 64 KHz, which is the frequency change caused by 1 bit of the present invention.

FIG. 7 is a flowchart illustrating an automatic storage method of the IF VCO auto-adjustment apparatus of FIG. 5 according to the present invention. The operation of the IF VCO auto-adjustment apparatus checks whether or not to perform "VCO auto-adjustment" by the OSD signal. 80 transmits specific channel data to the tuner unit 10, and the tuner unit 10 transmits the tuned IF signal to the synthesis unit 40 of the IC chip 90.

At this time, the microcomputer 80 sends out the VCO adjustment bit value = "0", and the resonant frequency is sent to the combining unit 40 to make a resonance with the IF signal.

At this time, the IFI signal as the ID signal and the AFA and AFB signals as the AFT signal are checked.

When the IFI signal is high, it determines that there is a signal, and when AFA is high, it determines that it is in the incoming range of the AFT signal, and then sees the value when the AFB goes from high to low as the adjusted VCO adjustment bit value. If the AFA and AFB signals do not meet the conditions, increase the VCO adjustment bit by 1 to check the IFI, AFA and AFB signals.

At this time, it is checked whether the VCO adjustment bit value is 126, which is the maximum value, and if it is 126, the program is terminated.

Finally, when the IFI, AFA, AFB signal is confirmed, it is determined whether to store the bit value at the checked time point, and the VCO adjustment bit value is stored in the EEPROM 120 and the program is terminated.

8 is a diagram illustrating an intermediate-frequency VCO autotuning step of the present invention. First, in the channel selection check step, the automatic storage is performed to check whether a channel is selected by user selection and to tune a frequency according to the channel when the channel is selected. In the step, the control data already set and stored in the memory is read, and the switches are controlled to control the capacitor synthesized value for frequency resonance by tuning the capacitor of the capacitor switching unit 100 according to the read data.

Accordingly, the channel signal can be received by tuning the corresponding frequency according to the combined value of the switched capacitor.

The present invention does not require any IF VCO adjustment signal generator, IF signal monitor, jig for connecting the chassis (Chassis) signal, and at the time of adjusting with the existing control rod just by connecting the production signal to the chassis using the remote control adjustment Quality loss due to core breakage of the coil can be reduced, and adjustment time can be greatly reduced.

In addition, the software is sufficiently applicable to the software with little increase in cost compared to the function improvement.

Claims (6)

A TV for receiving a transmitted broadcast signal and outputting it to a screen through image processing and deflection processing, comprising: a tuner unit for selecting and outputting a specific channel by a control signal among the transmitted broadcast signals; An intermediate frequency processor for processing to tune to the intermediate frequency of the tuned channel; A synthesizing unit for synthesizing the signals for tuning and outputting a bit value for controlling the video signal and the intermediate frequency tuning for the tuned intermediate frequency signal; A detector for detecting an automatic frequency tuning (AFT) signal and an intermediate frequency detection (ID) signal, which are control bit values output from the synthesizing unit; An EEPROM for storing control bit values detected by the detector; And a tuner unit, an intermediate frequency processor, a detector, and a microcomputer for controlling the EEPROM through a bus line. The intermediate frequency processing unit of claim 1, the intermediate frequency adjusting coil unit used to synchronize with the intermediate frequency for the selected channel, and switching the capacitors connected in parallel to achieve the intermediate frequency tuning under the control of the microcomputer. Medium frequency VCO (VCO) automatic adjustment device, characterized in that consisting of a capacitor switching unit. 3. The apparatus of claim 2, wherein the capacitor switching unit comprises a plurality of capacitors to be used for frequency resonance, and a plurality of switches for switching the capacitors by a microcomputer control signal to produce a composite capacitor value necessary for frequency resonance using the plurality of capacitors. Medium frequency VCO (VCO) automatic adjustment device, characterized in that consisting of. In the automatic adjustment method of the intermediate frequency VIO, it automatically outputs the channel information of a specific channel and controls the switching of the capacitor while determining the adjustment value by using the automatic frequency tuning signal and the presence or absence of the intermediate frequency detection signal and then storing it in the memory. And an auto-adjustment step of first tuning the already set state by performing switching control for capacitor value determination by reading the adjustment value stored in the memory when channel selection is made. ) Automatic adjustment method. 5. The method of claim 4, wherein the automatic storing step comprises: outputting information of a specific channel tuned through a tuner unit, outputting an initial control adjustment value to a capacitor switching unit, and an automatic frequency tuning (AFT) signal based on the output control adjustment value. And determining whether an intermediate frequency detection (ID) signal is present, and if the automatic frequency tuning (AFT) signal and the intermediate frequency detection (ID) signal exist, determine a current control adjustment value. Determining the control adjustment value by repeating the process of determining the presence of the signal by increasing the control adjustment value, and storing the determined control adjustment value in the memory if it is desired to store the stored control adjustment value. Automatic adjustment of medium frequency VCO. 5. The method of claim 4, wherein the automatic adjustment step includes a channel selection confirmation step of confirming whether a channel is selected by a user selection, and control data stored in a memory to tune a frequency to a corresponding channel when the channel is selected by the step. A storage data read (READ) step of reading a readout, a switching control step of controlling a capacitor switching unit according to the read data, and a corresponding frequency tuning step of tuning a corresponding frequency according to a synthesized value of the switched capacitors. Automatic adjustment of medium frequency VCO.

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