JPH01302515A - Clogging detecting device for revolving head type reproducing device - Google Patents

Abstract

PURPOSE:To early detect and cancel clogging by reading sub code information, which are reproduced from a recording medium, and detecting the clogging of a revolving head according to the propriety of these information. CONSTITUTION:When the command of reproducing is outputted from an input part 1 to a microcomputer 2a, the reproducing command is outputted from the microcomputer 2a to a drum control circuit 3 and a capstan reel control circuit 4. Then, a signal is taken out from a tape by a revolving head 5 and the reproducing is executed. The microcomputer 2a reads the sub code information, which are recorded on the tape, or executes the display of the information or outputs a signal which are necessary for the turning-on and off, etc., of a capstan motor. The microcomputer 2a detects whether the frame address of the tape to be read from a signal processing circuit 8 is normally read or not. When the address is not normally read, it is judged that the clogging is generated in the revolving head 5 and the clogging is displayed on a clogging display part 11. By this detection of the clogging, the clogging can be immediately canceled with using a cleaning tape, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a clogging detection device for a rotary head type playback device such as a video tape recorder or a digital audio tape recorder.

[Conventional technology]

Figure 2 shows a conventional rotary head type playback device, where 1 is an input section such as a switch, 2b is a microcomputer, 3 is a drum control circuit, 3a is a drum motor, 4 is a capstan reel control circuit, and 4a is a capstan reel. A motor, 5 a pair of rotary heads installed on the side of the drum, 6 a small signal amplification unit that amplifies the electrical signal detected by the rotating head 5, and 7 data that converts the amplified analog signal into a digital signal. 8 is a signal processing circuit that performs error correction and subcode processing, 9 is a D/A converter, and IO is an output amplifier.

In the above configuration, a reproduction command is given from the input section 1 to the microcomputer 2b, this command is given from the microcomputer 2b to the drum control circuit 3 and the capstan reel control circuit 4, and the command is given to the drum motor 3a and the capstan reel motor 4a.
rotates so that it is in the playing state. Drum control circuit 3, drum motor 3a, and capstan reel control circuit 4
and the capstan reel motor 4a each form a control loop. When the drum motor 3a rotates, a signal is extracted from the part where the rotary knob 5 attached to the side of the drum contacts the tape, this signal is amplified by a small signal amplifier 6, and further converted into digital data by a data demodulator 7. Then, the signal processing circuit 8 converts the sound into digital data, the D/A converter 9 converts the sound digital data into a sound analog signal, and the output amplifier 10 amplifies this sound analog signal. Further, the microcomputer 2b reads subcode information stored on the tape from the signal processing circuit 8, issues display commands, and outputs necessary signals such as turning on and off the capstan motor.

[Problem to be solved by the invention]

The conventional rotary head type playback device is configured as described above, but when foreign matter adheres to the head gap of the rotary head 5 (this is called clogging), the rotary head 5 outputs a signal. The problem was that the signals could not be read and the signals would not be transmitted to the subsequent circuit elements 6 to 10, causing the operator to feel uneasy due to sudden disappearance of people or poor sound. Furthermore, even if only one rotary head 5 is clogged, it is difficult to detect it.

This invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a clogging detection device for a rotating head type playback device that can promptly detect clogging of a rotating head. .

[Means to solve the problem]

A clogging detection device for a rotary head type playback device according to the present invention is provided with means for reading subcode information reproduced from a recording medium, and means for detecting clogging of the rotary head when this subcode information is not normal. It is something.

[For production]

In this invention, subcode information read from a recording medium is read, and clogging of the rotary head is detected based on the fact that the subcode information is not normal.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1st
The figure shows the configuration of a rotary head type reproducing device including a clogging detection device according to this embodiment, in which 2a is a microcomputer, 11 is a clogging display unit that displays clogging according to commands from the microcomputer 2a, and the other configurations are as follows. Same as before.

In the above configuration, when a reproduction command is issued from the input section 1 to the microcomputer 2a, a reproduction command is issued from the microcomputer 2a to the drum control circuit 3 and the capstan reel control circuit 4, and loops are established with the control circuits 3 and 4, respectively. The forming drum motor 3a and capstan reel motor 4a rotate so as to be in a reproducing state. When the drum motor 3 rotates, the rotary head 5 picks up a signal from the contact part of the tape. From then on, as in the conventional case, this signal is amplified by a small signal amplifier 6, converted to digital data by a data demodulator 7, and then sent to a signal processing circuit. 8 converts the sound into digital data, and converts it to a donkey converter 9
The signal is converted into an analog sound signal and amplified by the output amplifier 10.

The microcomputer 2a reads the subcode information recorded on the tape from the signal processing circuit 8, and outputs necessary signals such as display and turning on/off the capstan motor.

Also, in a normal playback state, the microcomputer 2a performs the operations shown in the flowchart of FIG.
Now, set the count number of the operation loop to 0 and proceed to step 2.
In step 1, the frame address is read from the digital sound data from the signal processing circuit 8, and in step 22, it is determined from the read contents whether or not the frame address has been read normally. In this case, since the pair of rotary heads 5 have the same frame address, the same frame is
If the frame address is read twice and the frame address increases by 1 each time, it is determined to be normal. The frame address is OOH after OFH, and continues in a circular manner. If the frame address has been read normally, the process returns to step 20. If the frame address has not been read normally, 1 is added to the loop count number in step 23.

In step 24, it is determined whether or not a predetermined number of loops has been reached. If the number of loops is not the predetermined number, the process returns to step 21. If the number of loops has reached the predetermined number, the rotation
It is determined that clogging has occurred, and the clogging is displayed on the clogging display section 11 in step 25. The reason why the condition for clogging detection is that the predetermined number of loops has been reached is that the inability to read the frame address normally occurs due to clogging of the rotating head 5, but it may also occur in other cases. It is from.

In the embodiment described above, clogging of the rotary head can be detected when the frame address of the tape cannot be read normally, and it is also possible to detect clogging when one of the rotary heads 5 is clogged. Therefore, clogging can be eliminated by using a cleaning tape or the like, and it is possible to prevent substantial playback failure and deterioration in sound quality.

In the above embodiment, clogging is detected based on whether the frame address can be read normally, but clogging may be detected based on other subcode information such as block addresses.

Further, the present invention can also be applied to a reproducing section of a recording/reproducing device.

〔Effect of the invention〕

As described above, according to the present invention, clogging of the rotating head is detected based on whether the subcode information reproduced from the recording medium is normal or not, and the clogging can be quickly eliminated by using a cleaning tape or the like. This prevents playback failure and deterioration of sound quality.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a rotary head type reproducing apparatus according to the present invention, FIG. 2 is a block diagram of a conventional apparatus, and FIG. 3 is a flowchart showing the operation of essential parts of the apparatus of the present invention. DESCRIPTION OF SYMBOLS 1... Human power part, 2a... Microcomputer, 5... Rotation throat, 8... Signal processing circuit, 11... Clogging display part. Note that the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa

Claims (1)

[Claims] In a rotary head type reproducing device that reproduces a main signal as a digital signal from a recording medium via a rotary head and also reproduces subcode information, there is a means for reading the subcode information, and a means for reading the subcode information, and when the rotary head A clogging detection device for a rotary head type playback device, characterized in that the clogging detection device is provided with a means for detecting clogging.