JPH0610502Y2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a magnetic recording / reproducing apparatus capable of recording or reproducing by simultaneously driving a plurality of recording media such as a double cassette type VTR.

[Conventional technology]

The double-cassette type VTR has a pair of drive mechanisms that can be connected to the tape cassettes to be loaded so as to drive two tape cassettes at the same time. Circuit and second VTR drive circuit). The pair of drive mechanisms are independently operated in various modes (recording mode, reproduction mode, by operating the first and second VTR operation keys as switch means mounted on the operation panel).
It can be set to a stop mode, a fast-forward mode, etc. (JP-A-58-150106, JP-A-57-822).
42).

In the conventional single-cassette type VTR, when the operation key is operated to set the drive mechanism to the recording mode, for example, a motor for driving the capstan, a solenoid for pressing the pinch roller to the capstan, and the like are driven. The current I is
Due to a so-called electric circuit transient phenomenon, as shown in FIG. 4, a sharp increase occurs within a very short time T (about 5 msec), and a peak is generated, after which a stable level is reached. Therefore, the current capacity value of the drive circuit is selected according to the maximum current value in the transient phenomenon.

[Problems to be solved]

As described above, the conventional double cassette VTR is provided with a drive circuit and an operation key for controlling the drive circuit independently for each drive mechanism, and two single cassette VTRs share a power source and are simply a mechanism. It was just a combination of the two.
Therefore, when the first VTR operation key and the second VTR operation key are operated at the same time, the currents flowing through both drive circuits may have peaks due to the transient phenomenon at the same time. Cassette type VT
A current capacity value twice as large as R is required.

Therefore, conventionally, even if one of the operation keys is operated for a certain time (for example, about 1 second), even if the other operation key is operated, the drive ON signal generated by the operation is prohibited from being input to the drive circuit. It has been performed to provide a circuit for doing so.

However, when the first VTR operation key and the second VTR operation key are operated substantially at the same time, one of the key operations becomes invalid, and therefore the key operation must be performed again after a certain period of time, which makes the operation complicated. There was a problem.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention has a storage means for storing an ON signal A to each drive circuit (3) generated when the switch means (2) is operated for each drive mechanism. Each ON from the storage means at different timing
A control means for sequentially calling signals and sending a drive command B to each drive circuit based on the ON signal is provided.

[Action]

When the switch means (2) is operated to operate an arbitrary drive mechanism, an ON signal is generated for the drive circuit (3) connected to the drive mechanism. The ON signal is directly supplied to the drive circuit (3)
Is not input to, but is temporarily stored in the storage means.

By operating the switch means (2) for other drive mechanisms as well, the ON signal for each drive circuit (3) is stored in the storage means in the same manner as described above.

The control means sequentially calls each ON signal from the storage means at different timings, and sends a drive command B to each drive circuit based on the state of the ON signal.

For example, the ON signal A is a code signal of "1" or "0" and is "1" when the switch means (2) is operated.
In this case, if the ON signal called from the storage means is "1", the control means sends a drive command B (for example, an energization start command to the solenoid) to the corresponding drive circuit.

The drive circuit (3) starts its operation in response to the drive command B from the control means, and receives the supply of the drive current from the power source to operate the respective drive mechanisms.

[Effect of device]

Even when the switch means (2) is simultaneously operated for a plurality of drive mechanisms, the ON signal A generated thereby is temporarily stored in the storage means, and the drive command B for each drive circuit (3) is given to the control means. Since the timing is forcibly shifted by the light emission, the peaks of the drive current I due to the transient phenomenon do not occur at the same time.

Therefore, the current capacity value of the drive circuit is set to the conventional single cassette type V
Compared to TR, it is not necessary to set it to a large value, and the switch operation for each drive mechanism is always required only once, which is simple.

〔Example〕

FIG. 1 shows a block diagram of an electric circuit when the magnetic recording / reproducing apparatus according to the present invention is applied to a double cassette type VTR, and a 4-bit one-chip microcomputer (1) is used as the storage means and the control means. ing.

As the one-chip microcomputer (1), for example, MB88420 manufactured by Fujitsu can be used.
PU (10), ROM (11), RAM (12), timer interrupt circuit
(13), an input / output buffer (14), an output port (15), an input port (16), and other well-known circuit elements.The input port (16) has a switch means (2) and an output port (15). ) Is connected to the drive circuit (3).

The switch means (2) includes a first VTR operation key (20) and a second VT.
An ON signal A (signals A ₁ and A ₂ described later) generated by operating the respective operation keys with the R operation key (21) is input to the microcomputer (1). The microcomputer (1) includes a first VTR drive circuit (30) and a second VT.
Drive command B to the R drive circuit (31) (signal B ₁ described later,
B ₁ ′, B ₂ and B ₂ ′). Both drive circuits (30) and (31) have a common power source and are connected to the first and second VTR drive mechanisms (not shown), respectively.

FIG. 2 shows, as an example, a timing chart of input / output signals of the microcomputer (1) when both drive mechanisms of the VTR are set to the reproduction mode and the pinch roller crimping mechanism which is a part of the drive mechanism is operated. There is.

The solenoid, which is the power source of the crimping mechanism, generates a strong suction force for a certain period of time (for example, 50 msec) at the initial stage of operation to promptly press the pinch roller to the capstan, and after the crimping, the normal suction force is applied to maintain the crimped state. It is necessary to operate so as to hold. Therefore, from the microcomputer (1), the drive start signals B ₁ and B shown in FIGS.
₂ and drive hold signals B ₁ ′ and B ₂ ′ shown in FIG. 2 (f) (h) are issued to the first and second VTR drive circuits (30) (30). The drive start signals B ₁ and B ₂ are signals that are at the H level for 50 msec, and a relatively large exciting current is supplied to the respective solenoid coils of the first and second VTR drive circuits by the signals, and as a result, the respective solenoid coils are respectively supplied. This solenoid produces a strong suction force. Further, the drive hold signals B ₁ ′ and B ₂ ′ are signals which maintain the H level until the next mode change is made, and the solenoid coil is supplied with the excitation current of the normal level by this signal, and as a result, The solenoid generates an attractive force that is strong enough to hold the magnetic tape.

3A and 3B show the RO of the microcomputer (1), respectively.
It is a flow chart which shows the important section of the program written in M (11).

The operation of the circuit shown in FIG. 1 will be described in detail below with reference to FIGS. 2 and 3A and 3B.

As shown in FIG. 3A, the first and second VTR operation keys (20)
When (21) is operated, the CPU (10) determines (40) whether the operated key belongs to the first VTR or the second VTR.
First, when the first VTR operation key (20) is pressed, the first VT
The R drive mechanism changes the mode from the stop mode to the reproduction mode (41), and as shown in FIG. 2 (c), an ON signal A ₁ is generated which changes the signal level almost at the same time as the key operation (4).
2) and written in a predetermined area of the RAM (12) (43).
Specifically, the ON signal A ₁ is a code signal of “1” or “0”, and the RAM is immediately after the first VTR operation key (20) is pressed.
The area can be rewritten from "0" to "1". afterwards,
The same procedures (44) to (46) are performed for the operation of the second VTR operation key (21), and the ON signal A ₂ as shown in FIG. Written to area (47).

The timer interrupt circuit (13) of the microcomputer (1) is 5m
Interrupting the CPU (10) at a cycle of sec,
As a result, the CPU (10) causes the RAM (12) every 5 msec.
The ON signals A ₁ and A ₂ stored in are alternately called.
The timing of this calling is shown in FIGS. 2A and 2B as the first VTR output timing and the second VTR output timing, respectively. Both output timings have a cycle of 10 msec and a phase difference of 5 msec. C
When the PU (10) receives the timer interrupt (in FIG. 2) as shown in FIG. 3B, it is the output timing of FIG. 2 (a) or the output timing of FIG. 2 (b). (50) is determined. If it is the output timing of the first VTR, based on the signal state of the called ON signal A ₁ , that is, the code signal “1”, the first VTR drive start signal B ₁ and the _first VTR drive start signal B ₁ shown in FIG. The 1VTR drive hold signal B ₁ 'is sent from the output port (15) to the first VTR drive circuit (30) (51).

After 5 msec from the timer interrupt, the next timer interrupt (shown in FIG. 2) is applied, and after it is confirmed that the output timing of the second VTR is reached, the signal state of the called ON signal A ₂ , that is, the digital signal “1” is set. Based on Fig. 2 (g)
The second VTR drive start signal B ₂ and the second VTR drive hold signal B ₂ ′ shown in (h) are sent from the output port (15) to the second VTR drive circuit (31) (52). At this time, both signals B ₂ and B ₂ ′ are
The signals B ₁ and B ₁ ′ to the _first VTR drive circuit (30) are generated with a phase delay of 5 msec respectively.

Therefore, the first VTR operation key (20) and the second VTR operation key
(21) and are operated almost at the same time, as shown in FIG.
Even when the ON signal A ₁ and the second VTR ON signal A ₂ are generated at the same time, the peak currents flowing in the solenoid coils of both drive circuits (30) and (31) are generated with a phase difference of 5 msec. Excessive current does not flow to.

Of course, the present invention can be applied not only to a double cassette type VTR but also to a VTR having three or more drive mechanisms.

[Brief description of drawings]

FIG. 1 is a block diagram of an electric circuit of a magnetic recording / reproducing apparatus according to the present invention, FIG. 2 is a timing chart of signals produced in the circuit of FIG. 1, and FIGS. 3A and 3B are respectively FIG. FIG. 4 is a flowchart showing the main part of the circuit operation of FIG. 4, and FIG. 4 is a diagram showing the peak current flowing in the drive circuit. (1) …… Microcomputer (2) …… Switch means, (3) …… Drive circuit

Claims (2)

[Scope of utility model registration request] 1. A driving mechanism is provided for each recording medium so as to simultaneously drive a plurality of recording media, and each driving mechanism is connected to a driving circuit having a common power source, and the driving circuit is turned on by operating a switch means. -In a magnetic recording / reproducing apparatus capable of operating each drive mechanism by controlling OFF, ON to each drive circuit caused by operation of switch means
First storage means for storing a signal, a first program for writing an ON signal generated by the switch means when the switch means is operated, and a first program stored in the first storage means. Second storage means for storing an ON signal for each drive circuit sequentially at different timings and a second program for issuing a drive command to each drive circuit based on the ON signal; A magnetic recording / reproducing apparatus comprising: a control unit that controls a second storage unit. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the recording medium is a magnetic tape.