KR940005850B1 - High speed search control method for dat - Google Patents

Abstract

The method is for searching the first part of the recorded music quickly with information concerning the start index, no-sound indication signal, and other existing digital audio tape recoding information. After reading the first part of the music and the program number. The microprocessor calculates the length (track number) from the stop point of the capstan motor shifted by the high speed inertia so that the speed of the reel is controlled only by the capstan motor regardless of the time constant of the mechanism. Then the reel motor is not necessary.

Description

High-speed search control method of digital audio tape recorder

1 is a hardware block diagram applied to the scheme of the present invention.

2 is an explanatory diagram showing a head scan vector at 200x speed.

3 is an explanatory diagram showing a head trajectory and a high frequency (RF) waveform when rewinding 200 times.

4 is a flow chart for rewind search control of the present invention.

5 is a flow chart for rewind search control of the present invention.

* Explanation of symbols for main parts of the drawings

1: microcomputer 2: digital signal processing unit

The present invention relates to a high speed search control method of a digital audio tape recorder, and more particularly, to a high speed search control method capable of performing a high speed search regardless of a mechanical time constant in a digital audio tape recorder driving a reel with a single drive source. will be.

In general, a digital audio tape recorder using a reel direct drive motor unconditionally travels 16 times in the reverse direction and 3 times in the forward direction, so that the search can be performed. At this time, if the start index is not found, there is a drawback of finding the start index of the previous song and searching for the song to be searched by driving 16 times again in the forward direction.

In addition, in a digital audio tape recorder that drives a reel with a single drive source, the search index of the song is found while performing a 3x review while FF searching, where the high-speed search speed is limited to about 100x speed. There is no choice but to. This is because the track's error range becomes larger due to inertia during high-speed search, and it takes too much time to compensate for this error at triple speed.

In general, the high-speed search of a digital audio tape recorder controls the relative speed between the speed of the drum motor and the tape linear speed determined by the driving source for driving the tape, so that the starting index and the program recorded in the subcode area of the tape track are recorded. This is done by reading the number. On the other hand, the tape standard of the digital audio tape recorder has a start index and a program number in the subcode area corresponding to the first 600 tracks (9 seconds) of each song, and a recording section is left for 4 seconds between the songs. However, since the track is passed by the inertia of the motor until the start index is read and the reel drive motor stops during high-speed search, it takes a considerable time to find the beginning of the song while changing the rotation direction of the motor again. In particular, there is a drawback in that it takes a long time to perform a high-speed search by driving a reel with a single drive source.

In order to solve the above-mentioned drawback, the present invention provides a high-frequency error distance between the beginning of a song searched by a microcom and a track when the actual motor is stopped during a high-speed search of a digital audio tape recorder driving a reel with a single drive source. Invented so that playback can be started at the beginning of a song to be searched for in a short time by calculating using an RF) waveform, which will be described in detail with reference to the accompanying drawings.

1 is a hardware block diagram applied to the method of the present invention. As shown therein, a high-frequency data such as a start index and a program number, and a data signal processor 2 for generating a silent part signal are shown. ), High-speed search by receiving the high frequency data and the silent signal, feed reel frequency (FGS), winding reel frequency (FGT), capstan motor frequency (CFG), drum motor frequency (DPG), high frequency (RF) waveform signals It consists of a microcomputer (1) to run.

FIG. 2 is an explanatory diagram showing a head scan vector at 200x fast forwarding, and tracks by skipping 66 tracks of the tape T at 200x fast forwarding, and the subcode SC of this tape T. Since the start index and the program number are recorded, the start index and the program number can be read.

FIG. 3 is an explanatory diagram showing a head trajectory and a high frequency (RF) waveform at 200x rewind speed. When the track of the tape T is tracked as shown in FIG. 3 (a), the high frequency (RF) waveform is shown in FIG. When the high frequency (RF) waveform is shaped by a waveform shaping circuit such as a comparator, the result is as shown in FIG. 3 (c).

The high-speed search control method of the present invention configured as described above will be described in detail with reference to the control flowcharts of FIGS. 4 and 5.

In the forward search, the microcomputer 1 reads the start index and program number of the song to be searched from the radio frequency (RF) data output from the digital signal processing unit 2, and stops the capstan motor driving the reel. The actual stop position passes over a predetermined distance from the start of the tune due to the inertia of the high speed rotating capstan motor. Therefore, in order to play back exactly at the beginning of the song, the capstan motor must be rotated again. In this process, if the distance from the actual stop position of the tape to the silent part is known in advance, the start point of the song can be reached quickly. This fast forward control flow is as shown in FIG.

When the fast-forward search signal is applied, first, the microcomputer 1 receives a silent signal from the digital signal processing unit 2 and detects the unrecorded portion of the tape. When the unrecorded portion is detected in this manner, the internal register R1, After the reset of R2 and R3, the register R1 is increased by using the rising trigger of the high frequency (RF) waveform shaping signal as a standby interrupt as shown in FIG. 3 (c). Instead, the number of tracks from the silent detection to the start index detection is calculated repeatedly until the start index is detected.

If the program number is not found, the process returns to the step of detecting the silent signal. If the program number is found, the register R1 is latched and the register R1 is reset. Then, using the reel rotation information FGS or winding reel frequency (FGT) as an interrupt to increase the value of the register (R2), this process is repeated until there is no capstan motor frequency (CFG), When there is no capstan motor frequency (CFG), that is, when the rotation of the capstan motor is stopped, the value of the register R2 is latched and the register R2 is reset, and then the capstan motor is driven 16 times in the reverse direction. While the winding frequency FGT is used as a standby interrupt, the value of the register R2 is increased, and the process is performed until the value of the register R2 is equal to the value of the latched register R2. Repeat.

Thereafter, using the drum motor frequency DPG as a standby interrupt, the value of the register R3 is increased, and when the value of the register R3 is 16 times the time to compensate according to the value of the latched register R1, Repeat until That is, the number of tracks, which is the value of the latched register R1, is probabilistically the distance between 0 and 9 seconds during normal playback, while knowing the number of tracks counted by the register R3, and therefore the number of tracks during normal playback. The distance between 0 and 9 seconds can be calculated, and thus, when rotating at 16 times the speed, it is only 1/16 hours later than normal playback. Therefore, when the drum motor is rotated at 2000 rpm at 16 times speed, the drum motor frequency (DPG) generated once per drum revolution can be counted to calculate the time to compensate as shown in the following equation.

600 (tracks): 9 (sec) = 2R1: X1 (sec)

2000 (drums): 80 (sec) = 1 revolution: X2 (sec)

시간을 보상하게 되면 된다.As a result, X2 hours

Compensate your time.

관계를 만족할 때 3배속으로 정방향 서치(CUE)한 후 시작인덱스에서 재생동작을 수행하게 된다.As a result, the value of the register R3

When the relationship is satisfied, playback is performed at the start index after forward search (CUE) at 3x speed.

On the other hand, the reverse search is performed as shown in the flowchart of FIG. 5 unlike the forward search. In other words, first find the start index and program number of the song you want to search for, and then reset the registers (R1) and (R2), and then use the supplied reel frequency (FGS) or reel frequency (FGT) as a standby interrupt. Increase the value of (R1) and repeat this process until there is no capstan motor frequency (CFG). Then, when there is no capstan motor frequency (CFG), latch the value of the register (R1) and rotate the capstan motor 16 times in the forward direction, and then use the supply reel frequency (FGS) or the reel frequency (FGT) as a standby interrupt. In this case, the value of the register R2 is increased, and if a silent signal is detected, forward search is performed, and then a playback operation is performed at a start index. If the silent signal is not detected, the value of the register R2 is latched. The process of increasing the value of the register R2 is repeated until the value of R1 is equal to that of R1, and then revived to perform a regeneration operation when a silent signal is detected.

As described in detail above, the present invention uses a start index, a program number, a silent signal, and information signals used in a conventional digital audio tape recorder to read the head and program number of a song to be actually reproduced. Due to the high speed inertia, it is possible to control the reel speed so that the head of the song can be found as soon as possible by calculating the distance (track number) from the point where the motor stops. Accordingly, without using the reel direct drive motor, Even inexpensive digital audio tape recorders that realize high-speed search with a single drive source have the effect of enabling fast high-speed search regardless of the mechanical time constant.

Claims (2)

After detecting the silent signal, the registers R1, R2, and R3 are reset and the frequency waveform shaping signal is used as a standby interrupt, increasing the value of the register R1 until the start index is detected rather than the silent part. If the program number is correct afterwards, the value of the register R1 is latched, the register R1 is reset, and the capstan using the supplied reel frequency FGS or the reel frequency FGT as a standby interrupt. Increase the value of the register R2 until there is no motor frequency CFG, latch the value of the register R2, reset the register R2, and then rotate the capstan motor 16 times in the reverse direction. Rotate and use the winding frequency FGT as a standby interrupt to increase the value of the register R2 until it is equal to the value of the latched register R2, and then wait for the drum motor frequency DPG. Inter By using Trojan

A high-speed search control method for a digital audio tape recorder, wherein the forward search is performed by increasing the value of the register (R3) until the relation expression is satisfied, and performing a forward search at a 3x speed, and playing back at a starting index. After detecting the start index and program number of the song to be searched, the registers (R1, R2) are reset, and then there is no capstan motor frequency (CFG) using the supply reel frequency (FGS) or the take-up reel frequency (FGT). Increase the value of the register R1 until it is latched, and then rotate the capstan motor 16 times in the forward direction, and wait for the supply reel frequency FGS or the take-up reel frequency FGT. Use it as an interrupt to increase the value of the register R2 until it is equal to the value of the latched register R1, and then perform a revie to reproduce when a silent portion is detected, and increase the value of the register R2. When the silent portion is detected during the process, the reverse search is performed by performing a forward search and playing at the start index.

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