JP2705226B2 - Digital magnetic recording / reproducing device - Google Patents

Description

The present invention relates to a digital audio tape recorder (hereinafter abbreviated as DAT), for example, when an error rate of data simultaneously reproduced at the time of recording is equal to or higher than a reference value, the data is recorded on the tape. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital magnetic recording / reproducing apparatus capable of easily inspecting a portion where a recording state of a tape is poor after recording is completed by holding a position.

2. Description of the Related Art A DAT can record additional information called a subcode in addition to a main signal. There are various subcodes, and a time code continuously written from the beginning of the tape is one of them. The time code is hour, minute,
It has second and frame information and can be used as absolute position information on the tape.

Incidentally, there is a so-called error rate as a scale indicating a data recording state on a tape. The error rate is not generated during recording, but is generated in the process of processing the reproduced data during tape reproduction. The cause of the deterioration of the error rate may be caused by a condition at the time of recording such as clogging of a recording head, but usually, it is often caused by tape damage such as a scratch on the tape.

However, DAT has a strong error correction capability so that even tapes with a low error rate can be sufficiently reproduced, and can perform data interpolation even when correction is impossible, so that DAT has a sufficient data reproduction capability. Therefore, just because the error rate is bad does not mean that it cannot be reproduced. The part with a bad error rate is certainly a part with a high possibility, but it is finally necessary to check the part with a really bad error rate.

 Hereinafter, a conventional DAT will be described.

6, reference numeral 60 denotes a microcomputer, 61 is a timer, 62 is a display, 63 is a signal processing circuit, 64 is a recording amplifier, 65 is a reproduction amplifier, 66 is a recording / reproduction switch, 67 is a cylinder, and 68 is a servo circuit. , 69 are digital signal input terminals, and 6A is a digital signal output terminal.

During recording, the recording / playback switch 66 is switched to the recording side. The main digital data input from the digital signal input terminal 69 is converted by the signal processing circuit 63 into recording data of a reference recording format. At this time, the time code and other subcodes generated by the timer 61 are sent from the microcomputer 60 to the signal processing circuit 63 at the same time. In the signal processing circuit 63, it is added to the above-mentioned recording data. Then, all the recording data is written on the tape via the recording amplifier 64 and the cylinder 67.

At the time of playback, the recording / playback switch 66 is switched to the playback side, and the playback data read from the tape passes through the cylinder 67 and the playback amplifier 65 to the signal processing circuit 63.
Is input to Therefore, the reproduced data is subjected to signal processing to be divided into main data and subcode, and at the same time, an error rate is calculated. The main data is directly output from the digital output terminal 6A, and the subcode such as the time code and the error rate are sent to the microcomputer 60. Then, the subcode is displayed on the display, and the error rate is compared with a reference value in the microcomputer. When the error rate exceeds the reference value, it is displayed on the display.

However, in the above-described conventional configuration, it is difficult to know whether the recording state is good or bad during the recording, and after the recording is completed, the user listens to the display or listens to the reproduced sound while reproducing the recorded portion of the tape. Otherwise, there is a problem that it takes a long time to inspect the recording state because the bad part of the recording state cannot be known.

The present invention solves the above-mentioned conventional problems. When the error rate of the reproduced data simultaneously reproduced at the time of recording is equal to or higher than a reference value, the position on the tape is held, so that the recording is completed. An object of the present invention is to provide a DAT capable of easily and quickly inspecting a portion having a low error rate.

Means for Solving the Problems The invention of claim 1 of the present application is directed to a digital magnetic recording / reproducing apparatus capable of simultaneously reproducing a main signal and time code as additional information of the main signal on a tape. Discriminating means for discriminating whether or not the error rate of the simultaneously reproduced signal exceeds a certain reference value; a memory for storing the time code of the portion as tape position information based on the discriminant output of the discriminating means; Running control means for high-speed searching for a portion where the error rate is equal to or higher than a reference value based on the time code.

Further, according to a second aspect of the present invention, in a digital magnetic recording / reproducing apparatus capable of simultaneously reproducing a main signal and additional information of the main signal on a tape, the error rate of a digital signal reproduced immediately after recording is improved. A discriminating means for discriminating whether or not a certain reference value is exceeded; and a recording means for recording information on the deterioration of the error rate in additional information of the portion based on the discrimination output of the discriminating means. .

According to the first aspect of the present invention having such features, the tape signal is simultaneously reproduced at the time of recording to determine whether or not the error rate exceeds the reference value. Time code is written to memory. Therefore, a position having a high error rate can be easily reproduced based on the time code recorded in the memory after the reproduction.

According to the second aspect of the present invention, when the error rate exceeds the reference value, the data is recorded in addition to the additional information. At the time of reproduction, a position having a high error rate can be reproduced easily based on the additional information.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a DAT in one embodiment of the present invention.

In FIG. 1, 10 is a microcomputer, 11 is a timer, 12 is a memory, 13 is a recording signal processing circuit, 14 is a recording amplifier, 15 is a cylinder, 16 is a recording head, 17 is a reproducing head, 18 is a reproducing amplifier, and 19 is a reproducing amplifier. Playback signal processing circuit, 1A is digital signal input terminal, 1B is digital signal output terminal, 1C is servo circuit, 1D
Is a group of switches for switching between recording and reproduction, supplying a reproduction signal for reproducing a position having a high error rate during reproduction, or switching a reference value of the error rate. Reference numeral 1E denotes a display.

The operation of the DAT configured as described above will be described below.

At the time of recording, the main data input from the digital signal input terminal 1A is converted by the recording signal processing circuit 13 into recording data of a predetermined format. At this time, the time code generated by the timer 11 is sent from the microcomputer 10 to the recording signal processing circuit 13. In the recording signal processing circuit 13, they are added as subcodes to the above-mentioned recording data. Then, the recording data is written on the tape via the recording amplifier 14 and the recording head 16.

The reproducing head is mounted at a position where recorded data can be reproduced with a delay of several frames, so that simultaneous reproduction at the time of recording can be performed. Reproduction data read from the tape by the reproduction head 17 is input to a reproduction signal processing circuit 19 via a reproduction amplifier 18. Therefore, the reproduced data is subjected to signal processing, divided into main data and subcode, and an error rate is calculated. Main data is output from the digital output terminal 1B. The time code and the error rate are transferred to the microcomputer 10, and the time code is displayed on the display 1E.

The error rate is compared with a reference value in the microcomputer 10, and if it is larger, a time code which is position information of the portion is stored. The reference value is switched by an external switch, and can be switched according to the degree of strictness of the inspection.

The time code storing process in the microcomputer 10 is as shown in FIG. That is, the error rate transferred by the reproduction signal processing circuit 19 is constantly compared with the reference value. The reference value can be switched by a switch, and is compared with a reference value corresponding to the position of the switch. Here, the microcomputer 10 achieves the function of a discriminating means for comparing the error rate with a predetermined reference value. When the error rate of the reproduced data becomes equal to or higher than the reference value due to tape damage or the like, the time code is stored at the address N of the memory 12. N is initialized at the start of recording. When the error rate worsens, it is not only one frame but several frames to several tens
Since the frame is considered to continue, the above processing is not performed for 30 frames after the time code is stored.

When the recording is completed, when the search switch is pressed, the stored time code is searched at high speed and stopped at the position of the target time code.

FIG. 3 shows this processing. When a search switch is pressed, a search start flag is set. If the flag is set, the magnitude relationship between the time code at the current position of the tape and the time code stored in the memory 12 is compared, and a traveling command is issued based on the result. For example, if the time code at the current position is larger than the stored time code, the search position is in the start direction, and the microcomputer 10 issues a command to the servo circuit 1C to run the tape in the start direction. The time code is also compared while the tape is running, and when the time code matches, a stop command is issued and the tape stops at the position of the stored time code. At the same time, the search start flag is cleared and the search operation ends. Here, in the flowchart shown in FIG. 3, the microcomputer 10 achieves the function of the traveling control means for performing a high-speed search for a portion where the error rate is equal to or higher than the reference value based on the time code.

As described above, according to the present embodiment, the error rate can be easily reduced by reading out the contents of the memory after recording without reproducing the entire recorded portion of the tape after the recording is completed and checking the recording state of the tape. It is possible to grasp the parts that are getting worse. In addition, since the reference value can be switched by a switch, it can be set in advance according to the degree of inspection.

Also, by using the DAT high-speed search, the location can be easily searched for and reproduced, so that the inspection time can be reduced.

Next, another embodiment of the present invention will be described with reference to FIG. In the present embodiment, the DA configured as shown in FIG.
At T, timer 11
Since the memory 12 is not used, its operation will be described below except for this.

At the time of recording, the main data input from the digital signal input terminal 1A is converted by the recording signal processing circuit 13 into recording data of a predetermined format. At this time, the time code generated by the timer 11 is sent from the microcomputer 10 to the recording signal processing circuit 13. In the recording signal processing circuit 13, they are added as subcodes to the above-mentioned recording data. Then, the recording data is written on the tape via the recording amplifier 14 and the recording head 16.

The reproducing head is mounted at a position where recorded data can be reproduced with a delay of several frames, so that simultaneous reproduction at the time of recording can be performed. Reproduction data read from the tape by the reproduction head 17 is input to a reproduction signal processing circuit 19 via a reproduction amplifier 18. Therefore, the reproduced data is subjected to signal processing, divided into main data and subcode, and an error rate is calculated. Main data is output from the digital output terminal 1B. The time code and the error rate are transferred to the microcomputer 10, and the time code is displayed on a display.

The error rate is compared with a reference value in the microcomputer 10, and if the error rate is large, information on the deterioration of the error rate is generated. The reference value is switched by an external switch,
It can be switched depending on the intended use.

The generated information is sent from the microcomputer 10 to the recording signal processing circuit 13 on the subcode information, and is recorded on the tape. The position at which the error rate has deteriorated and the recording position of the information at which the error rate has deteriorated do not exactly coincide with each other, but there is no particular problem since the inspection is generally performed for several seconds in the vicinity.

The processing in the microcomputer 10 is as shown in FIG. The transferred error rate is always compared with a reference value. The reference value can be switched by a switch, and is a reference value corresponding to the position of the switch. When the error rate of the reproduced data becomes equal to or higher than the reference value due to tape damage or the like, information on the deterioration of the error rate is transferred to the recording signal processing circuit 13. If the error rate deteriorates, it is thought that it will last not only one frame but also several frames to several tens of frames.
Try not to frame. Here, in the flowchart shown in FIG. 4, the microcomputer 10 achieves the functions of the determination means for determining whether the error exceeds the reference value and the recording means for recording the information when the error rate exceeds the reference value. .

When the search switch is depressed when the recording is completed, a high-speed search for information on the error rate deterioration on the tape is performed, and the operation is stopped. It is assumed that the condition for performing the search is to search for information on the deterioration of the error rate immediately before the tape position where the switch is pressed.

The process is shown in FIG. Pressing the switch sets the search start flag. If the flag has been set, the microcomputer 10 issues a command to the servo circuit 1C to cause the tape to run in the start direction. While the tape is running, the microcomputer 10 constantly monitors information on the deterioration of the error rate of the subcode, and when the microcomputer 10 finds the information, a stop command is issued and the tape stops. At the same time, the search start flag is cleared and the search operation ends.

As described above, according to the present embodiment, after the recording is completed, all the recorded portions of the tape are reproduced and the high-speed search after the recording is performed without inspecting the recording state of the tape, so that the location can be easily determined. Since it can be searched and reproduced, the inspection time can be reduced.

In addition, since the reference value can be switched by a switch, it can be set in advance according to the degree of inspection.

According to the present invention having such features, the main data is simultaneously reproduced while being recorded, and the error rate at the time of reproduction is compared with a reference value to maintain a position where the error rate is deteriorated. After the recording is completed, it is possible to easily recognize the portion where the error rate is deteriorated without reproducing the entire recording portion of the tape and checking the recording state of the tape. In addition, since the reference value can be switched by a switch, it can be set in advance according to the degree of inspection.

In addition, by using the DAT high-speed search, the location can be easily searched for and the inspection time can be reduced, so that the effect is large.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a DAT in one embodiment of the present invention, FIGS. 2, 3, 4, and 5 are flowcharts showing microcomputer processing, and FIG. 6 is the configuration of a conventional DAT. FIG. 10 …… Microcomputer, 11 …… Timer, 12 …… Memory, 13 ……
Recording signal processing circuit, 14: Recording amplifier, 15: Cylinder, 16: Recording head, 17: Reproduction head, 18: Reproduction amplifier, 19: Reproduction signal processing circuit, 1A: Digital signal input Terminal, 1B Digital signal output terminal, 1C Servo circuit, 1D Switch group, 1E Display, 60 Microcomputer, 61 Timer, 62 Display, 63 Signal processing circuit , 64: Recording amplifier, 65: Reproduction amplifier, 66: Recording / reproduction switch, 67: Cylinder, 68: Servo circuit, 69: Digital signal input terminal, 6A: Digital signal output terminal

Claims (4)

(57) [Claims] 1. A digital magnetic recording / reproducing apparatus capable of simultaneously reproducing a main signal and a time code as additional information of the main signal on a tape, wherein the error rate of the signal reproduced at the time of recording is a reference value. A memory for storing the time code of the portion as tape position information based on the determination output of the determination means, and an error rate based on the time code stored in the memory. A digital magnetic recording / reproducing apparatus, comprising: a traveling control unit for performing a high-speed search for a portion having a value equal to or larger than a reference value. 2. A digital magnetic recording / reproducing apparatus capable of simultaneously reproducing a main signal and additional information of said main signal on a tape, wherein an error rate of a digital signal reproduced immediately after recording exceeds a reference value. A digital magnetic recording / reproducing apparatus, comprising: a discriminating means for discriminating whether or not the error rate has been detected; and a recording means for recording information of an error rate deterioration in additional information of the portion based on a discrimination output of the discriminating means. 3. A running control means for performing a high-speed search for a portion where an error rate is equal to or more than a reference value based on additional information on the error rate deterioration recorded on the tape after recording is completed. Item 3. A digital magnetic recording / reproducing apparatus according to Item 2. 4. The digital magnetic recording / reproducing apparatus according to claim 1, further comprising switching means for externally switching the reference value of the error rate.