JPS6327764B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for setting optimal operating characteristics for a magnetic recording/playback machine that automatically sets optimal operating characteristics for recording and playback that match the magnetic characteristics of the magnetic tape used.

In recent years, various magnetic tapes with excellent magnetic properties have become commercially available, and magnetic tapes, including conventional magnetic tapes, can be used depending on the purpose. By the way, these magnetic tapes (normal type, chrome type, Ferrichrome type,
In order to maximize the performance of metals, etc.),
Each individual tape must be used in an optimal recording state according to its type, and more precisely, even if it is the same type of magnetic tape, it must be used in an optimal recording state according to the magnetic characteristics of each magnetic tape. In order to satisfy these optimal recording conditions, it is necessary to set the recording circuit and playback circuit to the optimal recording level, optimal recording bias, optimal recording equalizer, etc. that matches the magnetic characteristics of the magnetic tape used. Operating characteristics need to be set. Optimum operating characteristic setting devices for various magnetic recording and reproducing machines have been provided which automatically set these optimum operating characteristics.
By the way, the conventional optimal operating characteristic setting device for this type of magnetic recording/playback device usually uses a switch (an auto-tuning switch) for commanding the optimum operating characteristic, which is provided on the operation panel of the main body of the magnetic recording/playback device equipped with this device. It is designed to be activated when the is operated. In other words, if you want to record under the optimal operating characteristics in a conventional magnetic recording/playback device equipped with this type of device, you must attach the magnetic tape and operate the auto-tuning switch to set the optimal operating characteristics. Start, confirm that the optimal operating characteristics settings are complete,
This had the disadvantage of extremely poor operability since it was necessary to perform operations in sequence such as operating a recording start command switch to start recording. In particular, since the auto-tuning switch must be operated separately before operating the recording start command switch, it is possible to forget this operation and start recording without using the optimum operating characteristic setting function. There was also a drawback.

This invention was made in view of the above-mentioned circumstances, and its purpose is to provide an optimal magnetic recording and reproducing machine with extremely easy operation, which can automatically set the optimum operating characteristics with simple operation. An object of the present invention is to provide an operating characteristic setting device.

In order to achieve this object, the optimum operating characteristic setting device for a magnetic recording/playback device according to the present invention includes a tape attachment detection means for detecting whether or not a magnetic tape is attached to the main body of the magnetic recording/playback device, and a magnetic a starting signal generating means that outputs a starting signal in response to the first recording start command within the period in which the tape is attached, and does not output the starting signal in response to the second and subsequent recording start commands within the period; activated by a activation signal output from the activation signal generation means,
The present invention is characterized by comprising an optimum operating characteristic setting means for automatically setting the optimum operating characteristic.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing the structure of an embodiment in which the present invention is applied to a three-head cassette type magnetic recording/reproducing machine. In this figure, 20 is a central processing unit (hereinafter referred to as CPU) such as a microprocessor.
This CPU 20 performs various controls described below while using a random access memory (hereinafter referred to as RAM) 22 according to programs stored in a read-only memory (hereinafter referred to as ROM) 21. is configured to do so. Reference numeral 30 denotes a white noise generator as a test signal source, and this white noise generator 30 generates a flat level noise signal (white This is a circuit that outputs noise). Further, 31 is a normal recording signal input terminal, 32 is a variable resistor, and 33 is a changeover switch _.
controlled by the input terminal 31 and the variable resistor 3
2 or the test signal output from the white noise generator 30. 40 is a recording level setting circuit which attenuates each signal selected by the changeover switch 33 and supplies it to the recording amplifier 45;
0 output O ₂ (4 bits), and resistors 42-1 to 42-, one end of which is selectively grounded by this switch circuit 41.
16 and the resistor 43 constitute a 16-stage variable attenuation circuit. Moreover, the recording amplifier 45 is
The frequency characteristic is changed by a recording equalizer circuit 46 whose resonance frequency is selected by the output _O3 of the CPU 20. The output of the recording amplifier 45 passes through a bias trap 47, is superimposed on a recording bias current supplied from a bias oscillator 48, and is supplied to a recording head 50. The bias oscillator 48 is configured such that its output, that is, the recording bias current is controlled by the voltage supplied from the recording bias setting circuit 60, and the recording bias current output from the bias oscillator 48 is controlled by the capacitor 51 and the variable resistor. The above-mentioned recording head 50 via the device 52
and a second erase head 55 (recorded test signal) via a switch 54 controlled by the output _O4 of the CPU 20. (erasing head). The recording bias setting circuit 60 includes a switch circuit 61 controlled by the output O ₅ (4 bits) of the CPU 20, and resistors 62-1 to 62-16, one end of which is selectively grounded by the switch circuit 61. , resistance 63
The base current is determined by this resistor 63 and one of the resistors 62-1 to 62-16.
It is a variable voltage power supply configured with an NPN transistor 64, and according to the output _O5 of the CPU 20,
The voltage supplied to the bias oscillator 48 is changed.

Next, 56 is a reproduction head, 71 is a reproduction equalizer circuit whose time constant is selected by the output _O6 of the CPU 20, 72 is a reproduction amplifier whose frequency characteristics are changed by the reproduction equalizer circuit 71, and the reproduction head 56 reproduces the signal. The generated signal is amplified by the reproducing amplifier 72 and sent to the selector switch 73.
is supplied to This changeover switch 73 is
The regeneration amplifier 72 is controlled by the output O ₇ of 20.
For normal recording and playback, the output is connected to the variable resistor 74.
Furthermore, when setting the optimum operating characteristics, the signals are switched and supplied to the deviation detection circuit 80 respectively. 75 is a line amplifier, 76 is a normal playback signal output terminal, and the signal supplied to the variable resistor 74 via the changeover switch 73 is connected to the variable resistor 74.
4, the signal is attenuated to an arbitrary signal level, and then amplified by a line amplifier 75 and outputted from an output terminal 76.

Next, the deviation detection circuit 80 determines the deviation of each signal level of the reproduced test signal at two predetermined frequencies, and the deviation between the signal level of the reproduced test signal and the reference signal level at the predetermined frequency. It is a circuit. In this deviation detection circuit 80, 81, 82, 83 are around 400Hz and 400Hz, respectively.
This is a bandpass filter (hereinafter referred to as BPF) that passes only signals around 10KHz.In this case, BPF81 is equipped with a white noise generator 3.
Test signal from 0 (reference signal in this case)
is supplied, and a reproduced test signal is supplied to the BPFs 82 and 83 via the changeover switch 73. And 84, 85, 86 are each BPF
Each signal level of the signal passing through 81, 82, and 83 is expressed as the corresponding DC level (these are respectively eo, em,
87 is the DC level output by the level detectors 84 and 85, respectively.
A differential amplifier converts the deviation between eo and em (eo-em) into a corresponding voltage signal, 88 is a level detector 8
5 and 86 are differential amplifiers that convert the deviation (em-eh) between the output DC levels em and eh, respectively, into a corresponding voltage signal. Further, 89 and 90 are AD converters that convert the voltage signals (analog quantities) respectively output by the differential amplifiers 87 and 88 into corresponding digital signals (digital quantities), and their respective outputs are
It is supplied to the CPU 20. In this case, the digital signal output by the AD converter 89 has an error (eo
-em), and the digital signal output by the AD converter 90 corresponds to the deviation (em-eh).

In addition, the ROM 21 mentioned above also has a DC level eo.
(This DC level eo is a reference level and is always a constant value), the deviation (eo-em), and the recording level correction amount required to match the current recording level to the optimal recording level ( This is defined as △G), and the relationship between the deviation (em-eh) and the recording bias correction amount required to match the current recording bias to the optimal recording bias (this is defined as △B). is stored in advance. Fig. 2 is a characteristic diagram showing the relationship between the value em/eo calculated from the DC level eo and the deviation (eo - em) and the recording level correction amount △G, and Fig. 3 is a characteristic diagram showing the relationship between the DC level eo and the correction amount △G of the recording level. The value eh/em calculated from the deviation (eo-em) and the deviation (em-eh) and the recording bias correction amount △
3 is a characteristic diagram showing the relationship with B, and these relationships are stored in the ROM 21 as, for example, a data table. The ROM 21 also stores information necessary for setting standard operating characteristics corresponding to various magnetic tapes (normal type, chrome type, metal type).

Next, returning to FIG. 1, reference numeral 91 denotes an operating section, and this operating section 91 includes an automatic setting designation switch (push button switch) 91a for specifying whether or not to perform automatic setting of optimal operating characteristics; It has a recording start command switch (push button switch) 91b for commanding the start of recording. Then, the output of the operation unit 91, that is, the automatic setting designation switch 91
Contact state signals such as a and the recording start command switch 91b are supplied to the CPU 20. Also, 92 is
A tape mounting switch 92a detects that the magnetic tape to be used is mounted on the main body of the magnetic recording/reproducing apparatus equipped with this embodiment, and a sensing hole (sensing switch) provided in the magnetic tape case (cassette half) corresponding to the tape type. This is a hole detection circuit equipped with hole detection switches 92b and 92c for detecting holes (holes). This Hall detection circuit 92
The outputs of the tape mounting switch 92a, hole detection switches 92b, 92c, etc. are supplied to the CPU 20.

In the above configuration, the tape mounting switch 92a constitutes the tape mounting detection means, and
The CPU 20, ROM 21, RAM 22, white noise generator 30, recording level setting circuit 40, recording bias setting circuit 60, deviation detection circuit 80, and hole detection switches 92b and 92c constitute optimum operating characteristic setting means.

Next, FIG. 4 shows the aforementioned recording head 50, erasing heads 53, 55, playback head 56, tape mounting switch 92a, hole detection switch 92b,
92c is a front view showing the arrangement of the magnetic tape 92c. In this figure, A indicates a cassette half, T indicates a magnetic tape, and arrow c indicates the running direction of the magnetic tape T during recording and reproduction. Here, the arrangement of the erasing head 53 (ordinary erasing head), the recording head 50, and the reproducing head 56 is similar to that of an ordinary three-head magnetic recording/reproducing machine. The erasing head 55 is provided specifically for erasing recorded test signals, and is disposed downstream of the reproduction head 56 along the running direction of the magnetic tape T during recording and reproduction. Further, the tape loading switch 92a is arranged to operate when the cassette half A is loaded. In addition, the hole detection switch 92
b, 92c are sensing holes 93 (metal holes) and sensing holes 94 in cassette half A.
They are arranged to operate depending on whether a chrome hole (chrome hole) is provided or not.

The operation of this embodiment having the above configuration will be explained below.

FIG. 5 is a flowchart showing the flow of the operation of this embodiment, and the following description will be made according to the flowchart of FIG. First, when the magnetic tape to be used is loaded, its cassette half A
Accordingly, the tape mounting switch 92a of the hole detection circuit 92 is operated. The CPU 20 reads the operating state of the tape mounting switch 92a, immediately detects that the magnetic tape has been mounted (step 1), and starts the following operations. First, the CPU 20 switches the hole detection switches 92b, 9
2c is read, and the type (normal type, chrome type, or metal type) of the attached magnetic tape is determined from these operating conditions (step 2). Then, the CPU 20 transmits the reference operating characteristics corresponding to the determined tape type to the corresponding information stored in advance in the ROM 21 to the recording level setting circuit 40, the recording equalizer setting circuit 46, the recording bias setting circuit 60, and the playback equalizer circuit. 71
The settings are made by outputting each to (step 3). Next, the CPU 20 reads the operating state of the automatic setting designation switch 91a of the operation section 91, and determines whether automatic setting is designated (step 4). If automatic setting is specified, the operating state of the recording start command switch 91b of the operation section 91 is read, and it is determined whether or not recording start has been commanded (step 5). If the start of recording is commanded (at this time the magnetic tape starts running), the changeover switch 73 is switched to the deviation detection circuit 80 side to start detecting the deviation described above (step 6), and then the changeover switch 33 to the white noise generator 30 side to start recording the test signal (step 7), and then switch 54 is turned on to start the operation of the erasing head 55 (step 8). Here, the CPU 20 takes into account the time it takes for the position on the magnetic tape that was at the position corresponding to the erase head 53 at the time of starting recording to reach the position corresponding to the playback head 56 to be about 0.6.
Wait for seconds. And after this 0.6 seconds have passed,
The CPU 20 executes the following two processes in parallel. In other words, the CPU 20 performs AD
Deviation (eo-em) output by converter 89
(step 10a) and calculate this deviation (eo−em)
and the stored reference level eo and the value em/eo
is calculated, and the recording level correction amount ΔG is derived from this value em/eo (step 11a). Then, the optimum recording level is determined from this correction amount ΔG and the stored reference recording level (this optimum recording level is stored in the RAM 22), and a signal corresponding to this optimum recording level is sent to the recording level setting circuit 40. By outputting to
12a). In addition, in parallel with these first processes, the CPU 20 performs second processing on the AD converter 9.
Read the deviation (em-eh) output by 0 (step 10b), calculate the value eh/em from this deviation (em-eh), the deviation (eo-em), and the reference level eo, and set this value eh The recording bias correction amount ΔB is derived from /em (step 11b). Then, the optimum recording bias is determined from this correction amount △B and the standard recording bias (this optimum recording bias is also
The standard recording bias is corrected to the optimal recording bias by outputting a signal corresponding to this optimal recording bias to the recording bias setting circuit 60 (step 12a).

Next, the CPU 20 switches the changeover switch 33 to the variable resistor 32 side (normal recording signal side) to enable the normal recording signal to be recorded (step 13), and then, at this point, the recording head 50 The process waits for about 0.4 seconds, taking into account the time required for the recording surface on the magnetic tape located at the position corresponding to the erase head 55 to pass through the erasing head 55 (step 14). When this 0.4 second has elapsed, the switch 54 is turned off to stop the operation of the erase head 55 (step 15), and the selector switch 73 is then switched to the variable resistor 74 side so that the normal playback signal is output to the output terminal 7.
6 (step 16). When the automatic setting of the optimum operating characteristics is completed in this way, the test signal recorded during this automatic setting (for a very short time) has been erased by the erasing head 55, and the normal recording operation can rewind the magnetic tape. It will start running as is.

Normal recording and playback operations, including recording immediately after the automatic setting of the optimum operating characteristics is completed, are performed under the same optimum operating characteristics until the magnetic tape is ejected. (loop with step 17 and step 18). Furthermore, if the automatic setting of the optimum operating characteristics is not specified in step 4 described above, the mounted magnetic tape will be used under the standard operating characteristics until it is ejected (as determined by step 4, step 4a, and step 4b). loop). In addition, if automatic setting of the optimum operating characteristics is specified in step 4, if a playback start command is performed without first performing a recording start command, a loop of step 5, step 5a, and step 5b is performed. Accordingly, the optimum operating characteristics of the loaded magnetic tape are automatically set by the first command to start recording before the magnetic tape is ejected.

As explained above, the optimum operating characteristic setting device for a magnetic recording/playback device according to the present invention includes a tape attachment detection means for detecting whether or not a magnetic tape is attached to the main body of the magnetic recording/playback device; a starting signal generating means that outputs a starting signal in response to the first recording start command within the period in which the device is worn, and does not output the starting signal in response to the second and subsequent recording start commands within the period; Since the optimum operating characteristic setting means is activated by a starting signal output from the signal generating means and automatically sets the optimum operating characteristic, recording under the optimum operating characteristic can be performed in the same way as a normal recording operation. Simply attach the magnetic tape to the recorder, operate the recording start command switch to start recording, and the optimum operating characteristics will be automatically set just before the recording operation begins. It is extremely simple (that is, has good operability), and as a result, there is no chance of forgetting to set the optimal operating characteristics, unlike in conventional magnetic recording/playback equipment. Easy to operate, even for people who don't have one. In addition, unnecessary settings of optimal operating characteristics are not performed during the second and subsequent recordings of the magnetic tape that is still attached. Further, there is no need for a special switch or circuit for the optimum operating characteristic setting command, which is advantageous in terms of cost.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing the configuration of an embodiment of the present invention, Fig. 2 is a characteristic diagram showing the relationship between deviation and recording level correction amount in the embodiment, and Fig. 3 is a diagram showing the relationship between deviation and recording level correction amount in the embodiment. A characteristic diagram showing the relationship between the recording bias and the correction amount; FIG. 4 is a front view showing the arrangement of the tape loading switch, hole detection switch, and recording, playback, and erasing heads in the same embodiment; FIG. This is a flowchart for explaining the operation. 20...CPU, 21...ROM, 22...
RAM, 30... White noise generator, 40...
... Recording level setting circuit, 60... Recording bias setting circuit, 80... Deviation detection circuit, 91b... Recording start command switch, 92a... Tape mounting detection means (tape mounting switch), 92b, 92c...
Hall detection switch.

Claims (1)

[Claims] 1. A test signal is recorded and played back, and based on the state of the played test signal, the optimum operating characteristics of recording or playback or recording and playback are automatically determined according to the magnetic characteristics of the magnetic tape used. The apparatus for setting the optimum operating characteristics of a magnetic recording/playback device includes: a tape attachment detection means for detecting whether or not the magnetic tape is attached to the main body of the magnetic recording/playback device; and a period during which the same magnetic tape is attached. In response to the first recording start command, a start signal is output,
a starting signal generating means that does not output a starting signal in response to a second or subsequent recording start command within the period; and an optimum device that is activated by the starting signal output from the starting signal generating means and automatically sets the optimum operating characteristic. An optimal operating characteristic setting device for a magnetic recording/playback device, comprising: operating characteristic setting means;