KR0158323B1 - A vcr - Google Patents

Abstract

The present invention relates to a VCR with an audio level automatic adjustment function that maintains an optimal audio level adjustment state by automatically performing an audio azimuth screw adjustment based on the RMS level of a reproduced audio signal. And an amplifying unit for amplifying the audio reproduction signal detected by the head to a predetermined level, and an RMS level measuring unit for converting and outputting the level of the audio reproduction signal output from the amplification unit into digital decibel (dB) values. Azimuth screw for TRACKING adjustment, Level storage unit for storing the maximum detection level in forward and reverse rotation of the azimuth screw, respectively, The azimuth screw constant clockwise or counterclockwise An audio level adjusting unit having a step motor rotating by a displacement, and installed in the audio level adjusting unit according to a predetermined control signal. A motor driving unit for controlling the step motor, and controlling the motor driving unit to adjust the azimuth screw to an optimal phase by rotating the azimuth screw forward and backward by a predetermined displacement based on the data stored in the level storage unit. Characterized in that it comprises a control unit.

Description

VCR with automatic audio level adjustment

1 is a functional block diagram for explaining recording and playback functions of a conventional video cassette recorder (VCR).

2 is a view for explaining a process of manually adjusting the audio level.

3 is a block diagram showing an internal configuration of a VCR with an audio level automatic adjustment function according to an embodiment of the present invention.

4 is a flow chart for explaining the operation of the device of the configuration of FIG.

* Explanation of symbols for main parts of the drawings

1: remote control unit 2: receiver

3,33: microprocessor 4: supply reel

5: Rewind 6: Head for recording / playback

7: R / P head drive unit 8: switching unit

9: Y-C separation unit 10: FM modulation circuit

11: frequency low frequency conversion circuit 12,20: mixer

13, 14, 21: amplifier 15: audio head drive unit

16: HPF (High Pass Filter) 17: FM demodulation circuit

18: LPF (Low Pass Filter) 19: Frequency High Frequency Conversion Circuit

22: preamplifier 23: RMS level measurement unit

24: memory 26: forward rotation MAX level storage

27: reverse rotation MAX level storage unit 28: audio level adjustment unit

29: motor drive unit 100: drum (DRUM)

101: A / E head 104: step motor

P5: AZIMUTH SCREW

HDI: CTL Head HD2: Audio Head

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video cassette recorder, and more particularly, to automatically adjust an audio azimuth screw (AZIMUTH SCREW) based on the FMS level of a reproduced audio signal, thereby automatically maintaining an optimal audio level adjustment state. A VCR with an adjustment function.

Widely used in general audio equipment, including video cassette recorders (hereinafter referred to as VCRs), magnetic tape is made by magnetizing a thin film uniformly coated with a magnetic material with a contracted electromagnetic signal corresponding to predetermined data. It is to be recorded or read in the reverse order, even in the case of a tape in which the current video or audio data is already recorded, it is possible to initialize and use the tape in a relatively simple manner through the magnetization process described above.

FIG. 1 is a functional block diagram illustrating the recording function of a conventional general VCR having the above-described functions. In FIG. 1, reference numeral 1 denotes a remote control apparatus for remote control of the entire apparatus, and 2 denotes a remote control apparatus 1 from this remote control apparatus 1. A receiver which receives the transmitted far-infrared signal and converts it into an electric code signal is output. 3 is a microprocessor as a controller that controls the operation of the apparatus as a whole based on the code signal output from the receiver 2.

In addition, reference numeral 4 is a supply reel for conveying the tape wound while rotating in a constant direction, 5 is a rewind reel to rewind the tape released from the supply reel (4), 6 is from the microprocessor (3) A recording / playback head (REC / PLAY) for recording a video signal or reading out the recorded video data from the feed conveyed from the supply reel 4 according to a predetermined control signal of the head. A head drive unit 8 for driving control of the head 6 is a switching unit that performs another switching switching to execute the recording or reproducing operation based on a predetermined control signal from the microprocessor 3.

On the other hand, reference numeral P _in denotes a video signal input terminal for receiving a video signal applied from a TV receiver or a camcorder connected to a VCR, and reference numeral 9 is applied to the inside of the apparatus through this video signal input terminal P _in . YC separation unit for separating and outputting the video signal to be divided into the luminance signal (Y) and the color tone signal (C), 10 is a frequency modulation (FM) of the luminance signal (Y) is separated and output from the YC separation unit (9) FM modulation circuit, 11 is a frequency low-frequency conversion circuit for converting and outputting the tone signal (C) which is separated from the luminance signal in the YC separation unit 9 into a low-band frequency signal, 12 is the FM modulation circuit 10 and A mixer (MIXER) for mixing the luminance signal (Y) and the color tone signal (C) respectively output from the frequency low-frequency conversion circuit (11), 13 amplifies the video signal mixed in the mixer 12 to a predetermined level A signal for supplying the amplified signal to the fixed terminal (R; recording) of the switching unit (8) A unit.

Reference numeral HD2 denotes an audio head for recording and reading a voice signal, reference numeral 14 denotes an amplifier for amplifying and outputting a voice signal read from the audio head HD2, and 22 denotes the switching unit ( And a preamplifier for amplifying and outputting a video reproduction signal applied to the fixed terminal (P) side of 8).

Reference numeral 16 denotes a high pass filter (HPF) for detecting only the luminance signal Y among the reproduction signals output from the preamplifier 22, and 17 denotes the high pass filter 16. FM demodulation circuit for demodulating the luminance signal output from the following (hereinafter referred to as HPF), 18 is a low pass filter for detecting only the hue signal C among the reproduction signals output from the preamplifier 22; LPF (Low Pass Filter), 19 is a frequency high-frequency conversion circuit for converting the color tone signal output from the low pass filter 18 (hereinafter referred to as LPF) into a high frequency signal of a predetermined frequency band, and 20 is the FM double signal. Mixer (MIXER) for synthesizing the luminance signal (Y) output from the inquiry path (17) and the color tone signal (C) output from the frequency high-frequency conversion circuit (19), and 21 is an image synthesized by the mixer (20). An amplifier for amplifying a reproduction signal to a predetermined level, and reference numeral P _out 2 denotes this amplifier ( 21 is an output terminal for outputting an image reproduction signal amplified in 21) to an image output apparatus such as a TV.

That is, in the conventional general VCR having the above-described configuration, the user inputs a recording execution command through the remote controller 1, so that the audio signal is at the top of the track and the control signal CTL is the track based on the video signal. It is recorded at the bottom of each.

On the other hand, the VCR is a device that operates while a comprehensive mechanical mechanism is precisely interlocked with each other. Thus, even a small adjustment point has a great influence on the output state of a reproduction signal. Among them, the tracking of the audio head HD2 is particularly important. If the adjustment of the azimuth screw (AZIMUTH SCREW) is not correct, the output level of the reproduced voice is reduced, resulting in a decrease in the volume.

2 is a view for explaining a manual adjustment operation of the audio azimuth screw (AZIMUTH SCREW), the reference numeral P5 in the figure is an azimuth screw (AZIMUTH SCREW).

On the other hand, the azimuth screw (AZIMUTH SCREW) (P5) is coupled to the adjustment groove in the one-shaped groove formed on the top of the audio head (HD2) and CTL head (HD1) while moving up and down as the operator turns clockwise or counterclockwise ) Up and down the A / E head 101 formed integrally. If the position adjustment of the A / E head 101 is incorrect, the output state of the reproduced audio signal becomes poor.

Conventional volume level adjustment works by reproducing a standard tape conforming to the VHS standard at the time of shipment of the product, and turning the AZIMUTH SCREW (P5) clockwise or counterclockwise through a measuring instrument such as an oscilloscope. As a result of the extremely inaccurate method of visually observing the level of the reproduced signal, there was a problem that the operator was cumbersome, the adjustment time was long, the productivity was lowered, and the adjustment was inconsistent, so that it was difficult to obtain an optimal sound quality.

The present invention has been made in view of the above circumstances, and it is possible to maintain an optimal audio level adjustment state by automatically performing audio azimuth screw adjustment based on the RM5 level of the reproduced audio signal. The aim is to provide a VCR with automatic level adjustment.

In order to achieve the above object, the VDR having an automatic audio level adjustment function according to the present invention has an amplifying unit for amplifying a voice reproduction signal detected by a head to a predetermined level, and a digital reproduction level of the audio reproduction signal output from the amplification unit. RMS level measurement unit for converting and outputting to decibel (dB) value, azimuth screw for adjusting tracking of audio head, maximum detection level for forward rotation and maximum detection level for reverse rotation, respectively An audio level adjusting unit having a level storing unit for storing the azimuth screw by a predetermined displacement in a clockwise or counterclockwise direction, and driving control of a step motor installed in the audio level adjusting unit according to a predetermined control signal. The azimuth screw is fixed by a predetermined displacement based on the data stored in the motor driving unit and the level storing unit. It characterized in that it comprises a control unit for controlling the motor drive unit to be rotated in reverse rotation to fit the azimuth screw to the optimum phase.

That is, according to the present invention having the above-described configuration, the azimuth screw (AZIMUTH SCREW) adjustment can be automatically performed based on the RM5 level of the audio reproduction signal outputted from the amplifying unit during signal reproduction, which has been made through conventional manual work. It can improve productivity and reduce the possibility of misadjustment, and improve the adjustment method itself so that an optimal adjustment state can be obtained, and thus a better voice output can be obtained.

Hereinafter, with reference to the accompanying drawings will be described an embodiment according to the present invention.

3 is a block diagram showing the internal structure of a VCR with an audio level automatic adjustment function according to an embodiment of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 3, reference numeral 23 denotes an RMS level measuring unit for converting and outputting a level of a voice reproduction signal output from the amplifier 14 into digital decibel (dB) values, and reference numeral 33 denotes the azimuth screw. By comparing and calculating the signal level applied from the RMS level measuring unit 23 in a relative manner while (AZIMUTH SCREW) is rotated forward and backward by a predetermined displacement, it is based on the maximum level at the forward rotation and the maximum level at the reverse rotation. It is a microprocessor that outputs a predetermined control signal so that the azimuth screw (AZIMUTH SCREW) is fitted to the optimum phase at which the highest RMS level is detected.

Further, reference numeral 24 denotes a memory for sequentially storing RMS detection levels corresponding to each phase shift of the azimuth screw AZIMUTH SCREW under the control of the microprocessor 33, and reference numerals 26 and 27 denote the microcomputer. A level storage unit for storing the maximum detection level at the forward rotation (clockwise) or the maximum detection level at the reverse rotation (counterclockwise), respectively, according to a predetermined control signal from the processor 33, 28 Is an audio level adjusting unit equipped with a step motor (104) for rotating the azimuth screw (AZIMUTH SCREW) by a predetermined displacement in a clockwise or counterclockwise direction for automatic adjustment, and 29 is the microprocessor (33). And a motor drive unit for driving control of the step motor 104 provided in the audio level adjusting unit 28 according to the control signal output from the control unit.

Next, the operation of the device having the above configuration will be described with reference to the flowchart of FIG. 4.

First, when the user selects a play button (not shown) installed in the remote control device 1, the audio reproducing signal is output from the amplifying unit 14, and the microprocessor 33 plays back by the user. Once it is confirmed that the button is selected (ST 1), first set the current phase angle of the azimuth screw (P%) to 0 in the variable θ i (ST 2) and add the phase angle θ by 10 ° (ST). 3), the forward rotation drive control signal corresponding to the phase angle of 10 ° is output (ST 4) based on this data.

That is, the microprocessor 33 drives the step motor 104 by controlling the motor driver 29 connected to the rear end, thereby rotating the azimuth screw P5 forward by 10 °.

On the other hand, as the azimuth screw P5 rotates by a certain displacement amount from the amplifying unit 14, an audio reproduction signal whose level value is changed is output. The microprocessor 33 measures the RMS level of the signal. The digital signal is input through the unit 23 and is defined as a variable yi (ST 5), and then stored in the memory 24 corresponding to the current phase shift amount (ST 6).

Thereafter, when the azimuth screw P5 rotates 360 ° and rotates a full circle, the microprocessor 33 checks this (ST 7) and compares the data stored in the memory 24 in a relative manner (ST 8). The phase shift [theta] i at which the largest level was detected and the level value Ymax 1 at this phase are stored in the forward rotation MAX level storage section 26 (ST 9).

Subsequently, the microprocessor 33 performs a reverse rotation control on the azimuth screw P5, and the process is performed in the forward rotation control process (ST 2 to ST 9). While P5) is rotated at 10 ° intervals (ST 12 to ST 14), each signal level is stored in correspondence with the phase shift (ST 15 and ST 16), and these are compared and calculated to calculate the maximum level value (Tmax) in reverse rotation control. 2) and the phase angle θ _j corresponding thereto are stored in the reverse rotation MAX level storage unit 27 (ST 18 and ST 19).

When the maximum level value Ymax 1 for forward rotation control and the maximum level value Ymax 2 for reverse rotation control are obtained through the above process, the microprocessor 33 compares the two level values (ST 21). ), After allowing the azimuth screw P5 to be adjusted by the phase shift of the larger level value (ST 22, ST 23), the data stored in the level storage sections 26, 27 and the memory 24. (ST 24)

That is, according to the above embodiment, the azimuth screw P5 can be automatically adjusted based on the RMS level of the audio reproduction signal output from the amplifying unit 14 during signal reproduction. This can improve productivity and reduce the possibility of misadjustment.

The present invention is not limited to the above embodiments and can be variously modified within the scope not departing from the technical gist of the present invention. This allows the azimuth screw adjustment to automatically compensate for slight distortions.

Claims (1)

An amplifier for amplifying the audio reproduction signal detected by the head to a predetermined level, an RMS level measurement unit for converting and outputting the level of the audio reproduction signal output from the amplifier to a digital decibel (dB) value, and an audio head Azimuth screw for tracking (TRACKING) adjustment, Level storage unit for storing the maximum detection level of the forward rotation of the azimuth screw and the maximum detection level of the reverse rotation, respectively, Constant displacement of the azimuth screw clockwise or counterclockwise The azimuth screw is predetermined based on the data stored in the level storage unit, an audio level adjusting unit including a step motor for rotating by a step, a motor driving unit for driving control of a step motor installed in the audio level adjusting unit according to a predetermined control signal. Motor drive is controlled so that azimuth screw is in optimum phase while rotating forward and reverse by displacement. A VCR having an audio level automatic adjustment function, comprising a control unit.