KR940004222B1 - High speed searching method by using remaining time of record media - Google Patents

Abstract

calculating remaining time of a tape corresponding to the first spot of each program recorded in tape; storing the remaining time calculated by the calculating step; calculating the difference value of a present position of the and a destination position of a selected program in case of selecting the wanted program; operating super-speed forward mode in case that the difference value is higher than a predetermined value; operating super-speed reverse mode in case of lower value; and correcting remaining time error of the tape. The calculation of remaining time is calculated by RG pulse signal which is generated in a supply reel of a record replay device.

Description

Ultra-fast search method using remaining time of recording media

1 is a block diagram of an ultrafast search system according to the present invention.

2 is a layout of a digital audio tape.

3 is a flow chart of the invention performed in the system of FIG.

* Explanation of symbols for main parts of the drawings

1: display unit 2: key input unit

3: System control unit 4: Servo unit

5 signal processing unit 6 mechanism unit

7: Supply reel FG (Frequency Generator) sensor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of searching for a position of a recording medium in a recording and reproducing apparatus, and more particularly to an ultra-fast searching method for calculating and searching a remaining time of a recording medium.

In general, a recording / playback apparatus records or reproduces a video or sound signal on a recording medium. Types of recording and playback apparatuses include a video cassette recorder, an audio cassette recorder, a digital audio tape recorder (DAT), and a compact disk player (CDP). These recording and reproducing apparatuses search for the point when the playback is desired from the desired point. In particular, in the case of DAT, the search method is conventionally performed according to the presence of RF (Radio Frequency). However, the search by the presence or absence of such RF detection has a slow disadvantage. To compensate for this, recorded in the Subcode Data area on the tape as described in Korean Patent Application No. 90-16881 filed on October 22, 1990 by Icheon Sung of Samsung Electronics Co., Ltd. A technique for searching curve heads in a short time has been proposed by reading out start-demand (ST-ID) and program number (PNO) information. However, this method also has a problem in that the search speed is limited because the two heads are searched while reading the special codes ST-ID and PNO.

It is therefore an object of the present invention to provide a method for ultra-fast searching by calculating the remaining time of a tape in a recording / playback apparatus using a tape as a recording medium.

Another object of the present invention is to provide a method for ultra-high speed searching in accordance with the remaining tape time at the head of a recorded program in a recording / playback apparatus using a tape as a recording medium.

In order to achieve the above object, the present invention provides a fast search method of a recording / playback apparatus using a tape as a recording medium; A remaining tape time calculating step of calculating a remaining time corresponding to a leading point of each program recorded on the tape; A storage process for storing the remaining time calculated by the tape remaining time calculation process from the first start point of the tape to the last end point period; When a program to be searched is selected and controlled among the programs, a difference value is obtained between a current position of the tape and a target position at which the selected program is located. And a first high speed search process.

Next, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an ultrafast search system according to the present invention, which can be applied to DAT, VCR, ACR, and the like, which are recording and reproducing apparatuses using a tape as a recording medium.

In FIG. 1, the system control part 3 which connected each input terminal to the output terminal of the key input part 2, and the output terminal of the supply reel FG sensor 7, and the display part which connected the input terminal to the output terminal of the system control part 3, respectively. (1) and the servo part 4, the signal processing part 5 connected bidirectionally with the system control part 3, and the supply part FG sensor 7 connected in both directions with the servo part 4 and the signal processing part 5, It consists of a mechanism part 6 which connected the output terminal to the input terminal of ().

2 is a layout of the DAT, where (8) is tape, (9) is ST-ID information, (10) is PNO information, and (11) is the start (or the beginning of the ST-ID information of each program recorded on the tape). The remaining tape time at the head).

3 is a flowchart of the present invention performed in the system of FIG. 1, wherein step 12 is a process for calculating the remaining tape time, steps 13 to 20 are memory processes, and steps 21 to 29 are the first fast searching process. Step 30 is the second high-speed search process.

The operation of the present invention will now be described.

In FIG. 1, the key input unit 2 inputs a user's control command and information. Therefore, the operation mode control signal for the ultra-fast searching method of the present invention can also be input.

The system controller 3 controls all functions of the system by the control signal applied from the key input unit 2.

The servo unit 4 is controlled by the system controller 3 to control the operation of a motor such as a capstan motor and a drum motor for controlling the speed and position of the tape, and a motor for driving the system. To control.

The signal processing unit 5 receives a control signal from the system control unit 3 as applied to the servo unit 4, performs signal processing operations according to various modes on the tape, and outputs the signal processing result to the system control unit ( 3) and image display means (not illustrated).

The mechanism unit 6 controls the driving of various motors according to the control signal of the servo unit 4, so that the signal processing 5 can record and reproduce information according to the corresponding mode from the tape moved according to the driving of the motor. Controlled.

The supply reel FG sensor 7 senses the FG pulse generated by the supply reel of the mechanism part 6, and the sensing result is output to the system control part 3 and used to calculate the remaining time of the tape.

The display unit 1 displays various operating states of the system under the control of the system control unit 3. For example, the remaining time of the tape and information such as ST-ID and PNO recorded in the subcode area of the tape are then displayed. It is displayed variably at that time.

In FIG. 2, reference numeral 8 denotes a tape which is a recording medium in the mechanism part 6 of FIG. Bottom of Tape (BOT) is the beginning of the tape, and End of tape (EOT) is the final end of the tape. Reference numeral 9 denotes ST-ID information at the head of the program recorded on the tape. Therefore, the section where the pulse is high logic level is the point where the ST-ID information is recorded. Denoted at 10 is the program number divided into ST-ID information by PNO information. The above-described ST-ID information and PNO information are recorded in the subcode data area, and the detailed description thereof is the same as that described in Korean Patent No. 90-16881, which is omitted here. (11) is a general expression of the remaining time calculation of the tape. The remaining time calculation method is obtained using the physical property of TS = 2πrs / Vt. Where Ts is one rotation period of supply reel side, s is the radius of the tape wound on the supply reel, and Vt is the speed of travel of the tape. Therefore, the remaining time (TR) of the tape

It is expressed as here Is the tape thickness, o is the radius of the Hub.

3 is made in the system control unit 3 of FIG. 1 and will be described in conjunction with FIGS. 1 and 2.

First, in step 12, the remaining time Ts of the tape is calculated. This calculation method is the same as the above-mentioned formula (1), and more specifically, as described in Korean Patent Application No. 89-5962 issued by Ju Chang Nam of Samsung Electronics Co., Ltd. on May 3, 1989. This calculation is made by the sensing result of the supply reel FG sensor 7.

The remaining time corresponding to the beginning of each program among the remaining tape remaining time is stored (stored) in the storage element in the system control unit 3 (step 13). If no storage is made at all, the REW mode control signal is applied to the servo unit 4. Accordingly, the servo unit 4 controls the motors of the mechanism unit 6 to perform the REW mode. The REW mode is performed until the first point (BOT point) of the tape (step 14), and is switched to the FF mode until the EOT point is detected (steps 15 and 16). At this time, while performing the FF mode, the ST-ID information is read through the signal processor 5. The remaining tape time of the polling edge portion of the read ST-ID is stored (steps 17 and 18).

When the EOT point is detected, the system switches to the STOP mode (step 19), and sets the storage completion flag (lag) because the remaining time TR of the tape is stored for all programs recorded on the tape (step 20). .

Next, stay in the standby state with respect to the control signal applied through the key input unit 2 (step 21), and calculate the difference n between the current position of the tape and the target position, which is the position of the program to be searched ( Step 22). If the current position and the target difference are the same, the difference value n becomes zero, so the primary search control operation is completed. The system controller 3 checks whether the search control signal is applied again through the key input unit 2 (step 29). When the search control signal is applied, the above-described steps 21 to 23 are repeated, and if n is not 0, steps 24 to 28 and 30 to be described later are performed. On the other hand, if the search control signal is not applied, the operation ends.

If the difference value n is detected as a value other than 0 in step 23, the detected value n is compared with a predetermined value? T. Therefore, when n is larger than or equal to the predetermined value [Delta] t, the ultra fast search mode is set, and the system controller 3 outputs the ultra high speed search mode control signal to the servo unit 4 and the signal processor 5. At this time, if the sign of the difference value is positive (+), the target position exists at the rear side of the current position of the tape, so that forward ultra high speed search is performed (step 26). Since it exists in the front, the reverse ultra-high speed search is performed (step 27).

When the ultra-fast search operation is completed, the error of the remaining time of the tape is corrected to increase the precision (step 28). The system control unit recalculates the remaining time by checking the cycle of the supply reel as described in Korean Patent Application No. "89-15439" filed by Ju Chang-nam of Samsung Electronics Co., Ltd. on March 1989. The correction is made by the detected error compared to the current remaining time stored in (3).

If the difference value n is smaller than the predetermined value? T in step 24, the program head search mode of the normal high speed mode is performed (step 30). The program head search mode is also performed by searching the curve head by ST-ID and PNO information as described in Patent No. 90-16881. When the program (curve point) is detected, the program switches to the PLAY mode. do. Here,? T is an arbitrary value that is stored in the special register of the system control unit 3 and determines whether to set the ultra high speed mode or the general high speed mode. For example, if the current position of the tape is EOT designation, when the first point search program applied through the key input unit 2 is close to the BOT point like PNO 1 or 2 in FIG. If it is close to the EOT point, normal high speed mode is executed. The ultra high speed mode and the normal high speed mode have a speed difference of about 1.5 times.

As described above, the present invention has the advantage that the search of the curved head can be performed faster than the previous subcode reading and searching by using the super fast search (search) using the remaining tape time at the head of the program to be searched.

Claims (4)

A high speed search method of a recording / playback apparatus using a tape as a recording medium; A remaining tape time calculating step of calculating a remaining time corresponding to a leading point of each program recorded on the tape; A storage process for storing the remaining time calculated by the tape remaining time calculation process from the first start point of the tape to the last end point period; When a program to be searched is selected and controlled among the programs, a difference value is obtained between a current position of the tape and a target position at which the selected program is located. Ultra fast search method using the remaining time of the recording medium, characterized in that it comprises a first fast search process. The method of claim 1, wherein the high speed search method further comprises a second high speed search process for searching the target position at a high speed when the difference value of the first high speed search process is smaller than the predetermined value. Ultra-fast search method using remaining time of recording medium. The method of claim 2, wherein the first high speed search process comprises: performing a super fast forward direction (FF) mode when the sign of the difference value is positive (+), and performing a super fast reverse mode (REW) mode when the sign of the difference value is negative (-). And performing a process of correcting when an error in the remaining tape time occurs due to the forward mode execution and the reverse mode execution. 4. The method of claim 3, wherein the remaining time calculation is based on an FG pulse generated by a supply reel of the recording and reproducing apparatus.