KR100211255B1 - Circuit and method for searching audio non-signal recorded period - Google Patents

Abstract

The present invention relates to an audio non-signal recording section search circuit and method of VSI. The present invention relates to an audio no-signal recording section set to enable a learner to follow a language video tape when a video tape made for learning is played on VSI. In order to increase the learning efficiency when playing back a language tape by automatically searching and skipping according to the user's intention.

To this end, the present invention provides a variable gain amplifier for amplifying a low pass compensated audio reproduction signal with a variable gain ratio; A low pass filter for integrating the audio reproduction signal amplified by the gain variable amplifier; An audio detector configured to detect the presence / absence of an audio signal by comparing the output voltage of the low pass filter with a reference voltage; It consists of a microprocessor with a series of section search control program that searches for no-signal recording section in playback mode and proceeds to the forward search mode until the next audio signal is detected, and then proceeds to normal playback mode again when the audio signal is detected. Characterized in that.

Description

Searching Circuit and Method of Audio Signalless Recording Section of VSIAL

The present invention relates to an audio no-signal recording section search system of VSI. More specifically, an audio no-signal is set so that learners can follow a language video tape when playing a video tape produced for learning in VSI. The present invention relates to VSI's audio no-signal recording section search circuit and method for automatically retrieving and skipping recording sections according to a user's intention, thereby improving learning efficiency according to a user's learning level when playing a language tape. .

The conventional audio reproduction signal output circuit of VSI includes an audio head 10 for reproducing an audio signal recorded on a tape as shown in FIG. 1, and a reproduction equalization circuit unit for low-pass compensating and amplifying a signal reproduced by the audio head. 11) a muting circuit section 13 for controlling muting on / off by an audio mute signal sent from a servo circuit and outputting the audio signal low-compensated and amplified by the reproduction equalization circuit section to an audio output stage; And a first buffer section 12 and a second buffer section 14 for buffering the audio signal between the equalization circuit section and the muting circuit section or between the muting circuit section and the audio output section.

Referring to the audio reproduction signal processing operation in the conventional VSI having such a configuration, the signal reproduced from the audio head 10 passes through the reproduction equalization circuit unit 11 while the low frequency region is compensated and amplified to a predetermined level, and then the first buffer unit ( 12 is applied to the muting circuit section 13. In this case, the mute circuit unit 13 controls the output of the low pass compensation and amplified audio signal while controlling the operation by the mute on / off control signal supplied from the servo circuit, thereby converting the audio reproduction signal into the second buffer unit 14. It is then sent out to the audio output.

In addition, although not shown in the drawing, the conventional VSI includes a real-time counter to record the control pulse at the lower end of the tape during recording through the control pulse detection and recording means. The time is checked and the microprocessor can determine the playback state of the tape. The conversion relationship between the control pulse count value and time corresponds to 30 control pulses for 1 second for NTSC VSI and 25 for 1 second for PAL VSI.

In addition, the conventional VSI has one or two reel sensors for checking the remaining amount of the tape or removing the tape sagging, which is engaged with the hub of the video tape and is fixed with a certain pulse according to the forward or reverse travel of the tape. 4 or 8) to generate a reel pulse generated according to the forward / reverse running of the tape, using a counting means to increase / decrease the count value, and to display the display window provided on the front panel of VSI or The OSD processing means displays the running degree of the tape to the outside.

Therefore, when the user recognizes the corresponding part as the display contents by the display means, and designates the start point and the end point, and selects the section repeat function or the skip function, the microprocessor will repeat the start point and the start point of the section to be skipped. It selects the end point and controls the operation of the deck mechanism so that iteration or skipping is performed.

However, in order to perform a section repeat function or a skip function when playing a tape in such a conventional VSI, a user must select a random section by recognizing the section, and there was a lot of inconvenience in utilizing the section repeat function or the playback skip function, especially a language video. In the case of a tape, a non-signal recording section in which the audio signal is not recorded for repetitive learning is set in various parts of the middle of the tape. Such a no-signal recording section may be unnecessary depending on the user's learning level. When playing a video tape for language, it was time consuming to wait for the progress of the tape even though the learning section was skipped. When skipping the learning section by manual operation, there was a problem such as requiring a lot of cumbersome key operation. .

Therefore, the present invention was created to solve the above problems, and the present invention can determine the audio no-signal recording interval set for the learner to follow the language video tape produced for learning according to the audio level detection signal. If the user's intention is determined, the audio signalless recording section can be automatically searched and skipped, thereby improving the learning efficiency according to the user's learning level when playing the language tape. It is an object of the present invention to provide a section search circuit and a method.

In order to achieve the above object, the present invention provides a variable gain amplifier for amplifying a low pass compensated audio reproduction signal with a variable gain ratio; A low pass filter for integrating the audio reproduction signal amplified by the gain variable amplifier; An audio detector configured to detect the presence / absence of an audio signal by comparing the output voltage of the low pass filter with a reference voltage; It consists of a microprocessor with a series of section search control program that searches for no-signal recording section in playback mode and proceeds to the forward search mode until the next audio signal is detected, and then proceeds to normal playback mode again when the audio signal is detected. Provided is an audio-free recording section search circuit of VSI.

In addition, the present invention is a first step of determining that the section without the audio signal to the output of the audio detection unit proceeds for a predetermined time when the non-signal recording search mode is set in the playback mode; In the first step, if it is determined that the section without the audio signal proceeds for a predetermined time or more, the forward search until the section with the audio signal is checked while controlling the output of the mute circuit unit and controlling the amplification gain of the gain variable amplifier unit to be lowered. A second step of proceeding with a mode; A third step of performing a reverse search mode only for a predetermined time when the section in which the audio signal is present is checked in the forward search mode of the second step; After the third step, the output of the mute circuit unit and the fourth step of proceeding to the normal playback mode again while controlling the amplification gain of the gain variable amplification unit to increase the audio signal-free recording section of VSI Provide a search method.

1 is a block diagram of a conventional audio reproduction signal output circuit of VSI.

2 is a block diagram of an audio reproduction signal output circuit of VSI including an audio no signal recording section search circuit according to the present invention.

FIG. 3 is a flowchart illustrating signal processing when searching for an audio no signal recording section performed by the microprocessor of FIG.

* Explanation of symbols for main parts of the drawings

10: audio head 11: reproduction equalization circuit

12, 14: buffer section 13: muting circuit section

21: variable gain amplifier 22: low pass filter (LPF)

23: audio detector 24: microprocessor

25: key input unit AMP1: amplifier

COMP1: Comparator Q1: Transistor

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, an audio no-signal recording section search circuit and method of VSI according to the present invention will be described in detail with reference to the accompanying drawings.

Fig. 2 is a block diagram of an audio reproduction signal output circuit of VSI according to the present invention, which includes an audio head 10 for reproducing an audio signal recorded on a tape, and a low pass compensation and amplification of a signal reproduced by the audio head. A muting circuit section 13 for controlling the muting on / off by an audio muting signal sent from a servo circuit to a reproduction equalizing circuit section 11 and an audio signal low-compensated and amplified by the regulating equalization section. ) And the first buffer unit 12 and the second buffer unit 14 which buffer the audio signal between the reproduction equalization circuit unit and the muting circuit unit or between the muting circuit unit and the audio output terminal are the same as in the conventional case. It is composed.

In addition, a gain variable amplifier 21 for amplifying a low pass compensated audio reproduction signal with a variable gain ratio while passing through the reproduction equalization circuit 11 as a main part of the present invention, and the audio amplified by the gain variable amplifier. A low pass filter 22 for integrating a reproduction signal, an audio detection unit 23 for detecting the presence / absence of an audio signal by comparing the output voltage of the low pass filter with a reference voltage, and searching for a no-signal recording section in the reproduction mode. And a microprocessor 24 having a series of section search control programs which proceed with the forward search mode to a section where the next audio signal is detected, and proceeds to the normal playback mode when the audio signal is detected. A key input section 25 for interfacing with is configured.

The gain variable amplifier 21 includes an amplifier AMP1 for amplifying an audio reproduction signal with an arbitrary amplification gain, a plurality of amplification resistors R1 (R2) connected in parallel to a gain control stage of the amplifier, and the micro It is preferable that the transistor Q1 is configured to be changed on and off by the gain control signal G ctl of the processor to change the resistance value connected to the gain control terminal of the amplifier.

In addition, the audio detector 23 includes a comparator COMP1 configured to receive the voltage integrated in the low pass filter to the non-inverting terminal (+) and set a reference voltage to the inverting terminal (-) with two resistors (R4) and R5. Doing.

In addition, the microprocessor 24 may include a plurality of key scan terminals to scan a key input value pressed through the key input unit 25, and include an audio detection terminal A det to provide the audio detection unit 23. It is possible to check whether the audio reproduction signal is detected by the logic voltage output from the comparator COMP1 of the control unit, and the gain control terminal G ctl is provided to control the transistor of the gain variable amplifier 21 and mute the signal. It is preferable to provide a control terminal (MUTE) to selectively control the output of the muting circuit unit.

In addition, the key input unit 25 is preferably provided with a no-signal recording section search key so as to control whether or not the section search program built in the microprocessor is executed by user selection.

FIG. 3 is a flowchart illustrating an example of a section search program included in the microprocessor of FIG. 2.

In the drawing, the first step is a step (S10, S11) of checking whether the no-signal recording section search mode is set in the playback mode, and if the no-signal recording section search mode is selected, the input logic value of the audio detection terminal is read and the logic low level is checked. It is a step of checking the application (S12), and a step (S13) of determining whether the logic low level continues more than the first set interval (T1) arbitrarily set, wherein the first section is an audio signal between syllables and syllables Is preferably set to a section that can distinguish a portion where no signal is detected and a no-signal recording section.

The second step is a step performed when there is no abnormal audio detection signal in the first step. The mute control terminal is controlled to block the output of the audio reproduction signal and the amplification gain of the gain variable amplifier is lowered. Proceeding to the forward search mode while controlling the gain control terminal (S14), and checking the audio detection terminal while the forward search mode is performed to determine whether the section in which the audio signal is present is checked (S15). .

In addition, the third step is a step of performing an audio search signal when there is an audio detection signal in the forward search of the second step, and proceeding the reverse search mode only up to a randomly set second section T2 (S16). It is preferable to set T2 as a section for returning back to the portion where the actual audio signal is recorded since the audio signal is not immediately stopped at the portion where the audio signal is recorded, but proceeds forward even if the audio signal is detected during the forward search.

In addition, in the fourth step, after the third step is performed, the mute control terminal is controlled to output the audio reproduction signal output and the normal control mode is controlled again while the gain control terminal is controlled to increase the amplification gain of the gain variable amplifier. It is preferable that the step (S17) to proceed.

The operation of the present invention having the configuration as described above is as follows.

The overall operation of the present invention is that the signal reproduced from the audio head 10 passes through the reproduction equalization circuit section 11 while the low frequency region is compensated and amplified to a predetermined level, and then the muting circuit section 13 passes through the first buffer section 12. Is applied. In this case, the mute circuit unit 13 controls the output of the low-frequency compensated and amplified audio signal while controlling the operation by a mute control signal supplied from the mute control terminal MUTE of the microprocessor 24, thereby removing the audio reproduction signal. It is sent out to the audio output terminal via the two buffer unit 14.

In addition, the reproducing audio output, which has been compensated for the low frequency region and amplified to a predetermined level while passing through the reproducing equalization circuit 11, is simultaneously input to the gain variable amplifier 21, amplified to a predetermined level by the amplifier AMP1, and then a low pass filter ( It is integrated via 22 and is input to the audio detector 23. The audio detector 23 applies the logic value of the high level H when the output voltage of the low pass filter is higher than the reference voltage set by the two resistors R4 and R5 at the inverting terminal (-) of the comparator COMP1. If the output voltage is lower than the reference voltage, the logic value of the low level L is output and supplied to the audio detection terminal A det of the microprocessor 24.

Therefore, when it is determined that the no-signal recording search key is input from the key input unit 25 in the playback mode (Y branch in S10), the microprocessor 24 checks the audio detection terminal A det and then checks the audio detection unit 23 from the audio detection unit 23. Determine the incoming logical value. At this time, the audio detection terminal A det maintains a logic high level H when there is an audio reproduction signal and a logic low level L when there is no audio reproduction signal, so that the microprocessor uses the logic value as a determination signal for tape search progress. do.

As a result of the check, if the audio detection signal during reproduction reaches the logic low level (L), it is again checked whether the logic value lasts for a predetermined time (T1) (S13), and as a result of the check, the section without the audio signal is a predetermined time (T1). If the above operation proceeds, the deck operation mode is converted to the forward search mode, the logic high level (H) is output to the mute control terminal (MUTE) to cut off the output terminal signal of the mute circuit unit 13, and the gain control terminal (G ctl). The logic high level H is output to change the gain control amplification resistance to lower the gain of the amplifier AMP1.

Next, during the forward search mode, the microprocessor 24 continuously checks the audio detection terminal, and when the audio detection signal reaches a logic high level H, the microprocessor 24 proceeds in the reverse direction by a predetermined period T2 to be an excessive portion. After turning, change the deck operation mode to the forward regeneration mode, output the logic low level (L) to the mute control terminal (MUTE) to output the output terminal signal of the muting circuit unit 13, and to the gain control terminal (G ctl). By outputting the logic low level L, the gain control amplification resistance value is changed to increase the gain of the amplifier AMP1, and the tape is played back from that portion.

That is, when the audio signal is normally reproduced, the gain control terminal G ctl is controlled to maintain the logic low level, thereby blocking the operation of the transistor Q1 of the gain variable amplifier 21 so that the amplification resistor R2 is opened. In the amplifier AMP1, the amplification ratio is determined by one amplification resistor R1. On the contrary, since the audio output level is increased in the search mode, the gain control terminal G ctl is controlled to maintain the logic high level in the no signal recording section. Since the transistor Q1 of the gain variable amplifier 21 is operated, the amplification ratio of the amplifier AMP1 is determined by the combined resistance values R1 ∥ R2 of the two parallel resistors R1 (R2), thereby increasing the gain of the amplifier. This will lower the audio output level in seek mode.

According to the audio signal-free recording section search circuit and method of VSI according to the present invention, the audio-signal recording section is set so that learners can follow the video tape produced for learning. By automatically searching and skipping according to the intention of the, there is a useful to increase the learning efficiency according to the user's learning level when playing the language tape.

Claims (2)

A variable gain amplifier for amplifying a low pass compensated audio reproduction signal at a variable gain ratio through a reproduction equalization circuit; A low pass filter for integrating the audio reproduction signal amplified by the gain variable amplifier; An audio detector configured to detect the presence / absence of an audio signal by comparing the output voltage of the low pass filter with a reference voltage; It consists of a microprocessor with a series of section search control program that searches for no-signal recording section in playback mode and proceeds to the forward search mode until the next audio signal is detected, and then proceeds to normal playback mode again when the audio signal is detected. An audio no-signal recording section search circuit of VSI. A first step of determining that a section without an audio signal proceeds for a predetermined time or more to an output of the audio detector when a no-signal recording search mode is set in a play mode; In the first step, if it is determined that the section without the audio signal proceeds for a predetermined time or more, the forward search until the section with the audio signal is checked while controlling the output of the mute circuit unit and controlling the amplification gain of the gain variable amplifier unit to be lowered. A second step of proceeding with a mode; A third step of performing a reverse search mode only for a predetermined time when the section in which the audio signal is present is checked in the forward search mode of the second step; After the third step, the output of the mute circuit unit and the fourth step of proceeding to the normal playback mode again while controlling the amplification gain of the gain variable amplification unit to increase the audio signal-free recording section of VSI Search method.