JPH05182423A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To easily detect the length of a magnetic tape housed in a cassette tape. CONSTITUTION:When the cassette tape attached with a mark 2 for detecting the tape length is mounted on a magnetic recording/reproducing device, detection signals are outputted by a sensor circuit 3. The detection signals are sent out to an input means 11 through an input terminals group 20 of a microprocessor 10. In the input means 11, the detection signals sent out from the sensor circuit 3 are inputted as hexadecimal data. Next, in a selecting means 12, the data of tape length stored in a 1st data storage means 13 are selected based on the detection data sent out from the input means 11. The selected data of tape length are stored in a 2nd storage means 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus capable of easily detecting the tape length of a magnetic tape cassette.

[0002]

2. Description of the Related Art In a conventional video tape recorder, first, information on the tape thickness is read from the state of a switch set by an operator, and then the magnetic tape is run at a constant speed to send and rewind the magnetic tape. The tape length stored in the cassette is detected by performing arithmetic processing using the cycle of the signal corresponding to the rotation speed of each reel and the tape running speed.

[0003]

However, in the above-mentioned conventional structure, the operator has to set the tape thickness changeover switch, which is a problem in operability, and the length of the storage tape must be reduced unless the magnetic tape is run. Since it cannot be detected, there is a problem in that the remaining amount data calculated using the tape length cannot be immediately displayed.

[0004]

In order to achieve this object, the magnetic recording / reproducing apparatus of the present invention uses a magnetic tape cassette having a portion showing the length of a magnetic tape housed therein, and A tape length detecting means for detecting a portion indicating the length of the magnetic tape written on the tape cassette is provided.

[0005]

According to the present invention, the length of the magnetic tape accommodated in the magnetic tape cassette can be improved by attaching the tape length detecting mark to the magnetic tape cassette and providing the tape length detecting means for detecting the mark. Can be detected immediately.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a tape length detecting mark 2 is attached to a magnetic tape cassette 1. The sensor circuit 3 detects the tape length detection mark 2 attached to the magnetic tape 1, and the detection signal is input by the input means 11 as 1-word detection data. Next, the selection means 12 selects the tape length data stored in the first storage means 13 based on the detection data sent from the input means 11. The selected tape length data is stored in the second storage means 14. Here, the first storage unit 13 is a read-only memory (hereinafter, referred to as RO
M) and the second storage means 14 is a random access memory (hereinafter referred to as RAM). Input means 11, selection means 12, first storage means 1
The third and second storage means 14 are composed of software and hardware of the microprocessor 10. Further, the tape length detecting means 30 is composed of the sensor circuit 3 and the microprocessor 10.

Further, in this embodiment, the tape length detecting mark 2 is composed of three parts using two kinds of tapes, that is, a white tape and a black tape having different light reflectances, and represents eight patterns. be able to. That is, the tape length detection mark 2 is configured so as to be able to indicate eight different tape lengths. The sensor circuit 3 is composed of three detectors including a light emitting element and a light receiving element for detecting the tape length detection mark 2. Further, the input means 11 outputs three output signals from the sensor circuit 3
Input as bit data. Here, an example of the relationship among the actual tape length, the tape length detection mark 2 and the detection data input by the input means 11 is shown in Table 1.

[0009]

[Table 1]

The operation of the magnetic recording / reproducing apparatus configured as described above will be described. When the cassette tape to which the tape length detecting mark 2 is attached is mounted on the magnetic recording / reproducing apparatus of the present invention, the sensor circuit 3 detects a high level (5V) signal from the white portion of the tape length detecting mark 2. , A low level (0V) signal is detected from the black portion. The detected signal is sent to the input means 11 via the input terminal group 20 of the microprocessor 10. The input means 11 inputs the three detection signals sent from the sensor circuit 3 as 3-bit data. For example, as shown in (Table 1), a black tape is attached to all three parts of the tape length detection mark 2 on the 10-minute tape, and the sensor circuit 3 detects low-level signals for all three. .. Therefore, in the input means 11, 16
Zero will be detected as the binary data. In this way, by inputting the signal detected by the sensor circuit 3 as 3-bit data by the input means 11, the detected data has a one-to-one correspondence with the detected cassette, that is, the tape length. Therefore, in the first storage means, the detection data input by the input means 11 is used as an address, and the tape length data corresponding to the detection data is stored in advance in the ROM area indicated by the address data. The relationship between the tape length data stored in the ROM and the address is shown in (Table 2).

[0011]

[Table 2]

Next, the selection means 12 inputs the 3-bit detection data input by the input means 11 as ROM address data. Then, the tape length data written in the ROM area indicated by the address data is read,
It is sent to the second storage means 14. In the second storage means 14, the tape length data selected by the selection means 12 is stored in the RAM.
The data can be retrieved at any time through the data bus of the macro processor 10 as needed. Further, the tape length detecting means can be easily realized by using the macro processor 10.

As described above, according to this embodiment, the sensor circuit 3 detects the tape length detecting mark 2 attached corresponding to the tape length stored in the cassette, and the input means 1 is used.
1 reads as hexadecimal data. Furthermore, the selection means 1
In step 2, the tape length data stored in the ROM is read based on the data and transferred to the RAM, so that the tape length stored in the mounted cassette can be easily
Moreover, it can be detected immediately.

Although the tape length detecting mark 2 is composed of three parts in the present embodiment, the same effect can be obtained regardless of the number of divisions. However, the number of detectors forming the sensor circuit 3 and the number of terminals of the input terminal group 20 of the microprocessor 10 are required to be the divided numbers.

In this embodiment, the first storage means 1
Although 3 is configured by using a ROM, it may be configured by a RAM. Further, it goes without saying that the stored tape length data does not have to be the value shown in (Table 2) as long as it has a one-to-one correspondence with the actual tape length.

In this embodiment, white tape and black tape are used as the tape length detection mark 2, but it goes without saying that any color or material may be used as long as the two types of distinction can be detected.

[0017]

As is apparent from the above description, the magnetic recording / reproducing apparatus equipped with the tape length detecting means in the embodiment of the present invention detects the tape length which is attached corresponding to the tape length stored in the cassette. Mark 2 for sensor circuit 3
And read as hexadecimal data by the input means 11. Then, the selection means 12 reads the tape length data stored in the ROM based on the data and transfers it to the RAM, so that the tape length stored in the mounted cassette can be detected easily and immediately. be able to. Further, it is possible to quickly display the remaining amount data detected using the tape length, the current position on the magnetic tape, and the like. Moreover, a switch for detecting the tape thickness is not necessary.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a tape length detecting means of a magnetic recording / reproducing apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 cassette tape 2 tape length detection mark 3 sensor circuit 10 microprocessor 11 input means 12 selection means 13 first storage means 14 second storage means 30 tape length detection means

Claims (2)

[Claims] 1. A tape length detector for detecting a portion of the magnetic tape cassette indicating the length of a magnetic tape, using a magnetic tape cassette having a portion indicating the length of a magnetic tape housed inside. A magnetic recording / reproducing apparatus having means. 2. The tape length detection means stores a sensor circuit for detecting a portion indicating the length of the magnetic tape, an input means for inputting a signal detected by the sensor circuit, and a plurality of tape length data stored in advance. A first storing means, a selecting means for selecting the data stored in the first storing means by the data taken in by the input means, and a second storing means for storing the data selected by the selecting means. The magnetic recording / reproducing apparatus according to claim 1, comprising a storage means.