JPS6018861A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the destruction and erasion of the record information on a recording medium for reproduction due to the noise or a misoperation produced when the write protection is not processed yet, by providing a record inhibiting means via a changeover switch and therefore inhibiting the recording without performing the write protection processing at the recording medium side. CONSTITUTION:In a record/reproduction mode the level is set at a low level for the selection, motor-on, direction and step signals which are led to a disk drive motor control circuit 2 and a step motor control circuit 3 from the host system side via an input/output port 1. Thus both circuits 2 and 3 drive a disk drive motor and a step motor respectively. An output signal S3 of an OR gate 5 produced from a selection signal and the input signal of a write gate signal is led to a write control circuit 6 together with a write protection signal S2. The circuit 6 inhibits the recording in accordance with those signals S2 and S3 and a switching signal S1.

Description

TECHNICAL FIELD The present invention relates to a recording/reproducing device, and more particularly to a recording/reproducing device such as a magnetic disk device or a magnetic tape device that can record and reproduce information on a recording medium.

PRIOR ART There is a need for this type of recording/playback stop having both recording and playback functions. As a method for carrying out this prohibition, the conventional apparatus employs a method in which means is provided to detect whether or not the loaded recording medium is a recording medium on which recording should be prohibited, and recording is prohibited in accordance with the detection result.

For example, in a magnetic disk device, a part of the case or cassette that houses the disk as a recording medium has a notch or hole for write protection that indicates whether recording is possible or not. A detection means such as an optical sensor detects whether a portion is closed by a seal or the like, and recording is prohibited according to the detection result.

However, with this configuration, recording is not prohibited for all discs that have not been subjected to the write protection process of closing the detection portion of the case or cassette. Therefore, the recording function of the apparatus is still active even when the operator only wants to perform playback on a disc that has not been subjected to write protection processing, such as because the operator forgets.

In this case, there is a risk that the recorded information on the disk may be destroyed or lost due to noise recording or erroneous operation.

Moreover, in order to prevent this, write protection processing must be performed every time, which is time-consuming. The above configuration is not limited to magnetic disk devices, but is similar to other recording devices.

Purpose The present invention was made in view of the above circumstances.
In a recording/playback device that has both recording and playback functions, it is possible to inhibit recording without having to perform write protection processing on the recording medium side using an inexpensive and simple configuration, and prevents playback from the recording medium due to noise or erroneous operation when write protection is not processed. The object of the present invention is to provide a recording and reproducing device that can prevent the destruction and loss of recorded information.

EXAMPLES The present invention will be described in detail below based on examples shown in the drawings. Here, a magnetic disk device is used as an example of the recording/reproducing device.

FIG. 1 shows a circuit configuration for one disk drive of a magnetic disk device according to the present invention.

The reference numeral 1 in the figure is an input/output port for the magnetic disk device to the host system side, and it receives various signals from the host system side from the select signal to the step signal shown in the upper part of the figure, and the write game 1. Signals such as a write data signal s5 and a side select signal are input.

Of the above signals, a select signal indicating that a drive has been selected and a motor-on signal for driving a disk drive motor (not shown) are led to the disk drive motor control circuit 2. Further, a direction signal indicating the driving direction of a stepper motor for driving a carriage of a magnetic head (not shown) and a step signal for driving the stepper motor are led to a stepper motor control circuit 3. The output signals of both circuits are respectively guided to a disk drive motor and a stepper motor (not shown) via internal input/output ports 4, and the driving of both is controlled.

Also, the above select signal and the write gate signal for permitting recording from the host system side are the OR gate 5.
The output signal S3 is guided to the write control circuit 6. Write data signal S which is a data signal of recorded information
5 is also led to the write control circuit 6. The detailed structure of this write control circuit 6 will be described later, but a write protect signal s2, which is a detection signal indicating whether or not a write protect process has been performed on a disk mounted in the apparatus, is guided to this circuit.

The write control circuit 6 determines whether or not to inhibit recording based on the above output signal S3, write protect signal S2, and a switching signal described later, and when recording is performed, converts the write data signal S5 into write data signals WD, WD. and output it.

The write data signals WD and WD are guided to the head circuit 8 of the magnetic head for recording and reproducing through a switching circuit γ for recording and reproducing and switching between the 0th side and the 1st side of the disk, and recording is performed.

Here, switching between the 0 plane and the 1 plane is performed by a side select signal led from the input/output port 1 to the switching circuit 7.

A read circuit 9 is connected to the switching circuit 7, and during playback, a read signal is guided from the head circuit 8 to the read circuit 9 via the switching circuit 7, where it is amplified and input as a read data signal. Output to output port 1.

On the other hand, write protect signal S is sent to internal input/output port 4.
In addition to 2, there are 1 from each sensor (not shown), an index signal for detecting the index of the disk, and track 0.
A track 00 signal for detecting 0 and a cassette signal for indicating whether or not a disk cassette is installed are led, and these signals are sent to the input/output port 1 via various control circuits 10.
is output to the host system. Then, operations on the host system side are performed based on these signals.

Here, a display LED 11 is connected to the various control circuits 10 to indicate the operating status of the magnetic disk device.

The configuration described above is the same as the conventional configuration except for the write control circuit 6. That is, in the present invention, the configuration of the write control circuit 6 is different from the conventional one.

This write control circuit 6 will be explained below. The configuration of the circuit is shown in FIG. In the same figure, the number 12 indicates the Nands gate, and this Nands game 1
- One input of 12 is connected to the power supply +V via a resistor R. A changeover switch 13 for selectively switching over whether or not to prohibit recording is connected to the Nando Dozen 12 side of the resistor R.
The other end is grounded. Therefore, the switching signal S1 changes depending on whether this switch is turned on or off.
'1.2 is led to the input. Further, the aforementioned write protect signal S2 is introduced to the other input of the Nant gate 12, and the output signal S3 of the aforementioned OR gate 5 is introduced via the inverter 14.

The output signal of the Nant gate 12 is the write enable signal S
Output as 4. Here, write protect signal S2
, a select signal forming the output signal S3 of the OR gate 5, a write gate signal, and a write enable signal S4.
are all negative logic signals.

The output of the Nant gate 12 is connected to the clear CLR of the D flip-flop 16 via an inverter 15. A write data signal S5 is connected to the clock signal C of this D flip-flop 16, and a preset signal P is connected to the power supply terminal (2). Complementary output points are also connected to the manpower. Complementary output Q.

The write data signals WD and WD described above are output from Q.

Next, the operation of this embodiment having the above configuration will be explained.

During recording and playback, the levels of the select signal, motor-on signal, direction signal, and step signal guided from the host system side to the disk drive motor control circuit 2 and stepper motor control circuit 3 through the input/output port 1 become low level. As a result, the disk drive motor control circuit 2 and the stepper motor control circuit 3 drive a disk drive motor (not shown).

In addition, index signals, track 00 signals, and cassette signals are sent from each sensor (not shown) to the host system side via the internal input/output port 4, various control circuits 10, and input/output port 1, and based on these, the host system side performs an action.

Here, the output signal S3 of the OR gate 5 based on the input signals of the select signal and the write gate signal and the write protect signal S2 are led to the write control circuit 6, and the write control circuit 6 receives these signals and the above-mentioned switching signal S1. Recording is prohibited based on the following, and the operation is shown in Figure 3 (a) below.
, (b).

3(a) and 3(b) are timing charts of signals of each part of the write control circuit 6. FIG. Here, it is assumed that a disk (not shown) has been subjected to write protection processing. It is also assumed that the host system sets the write gate signal to a low level and sends a write data signal S5 in order to perform recording.

Here, when the changeover switch 13 is turned off in the light control circuit of FIG. 2, each of the signals 81 to S5 in the circuit,
WD, Wl': are as shown in FIG. 3(a).

That is, when the changeover switch 13 is turned off, the power supply voltage is applied, and the changeover signal S1 becomes high level. Next, unprocessed write protection is detected, and the write protect signal S2 becomes high level. In addition, when the select signal and write gate signal input to the OR gate 5 reach a low level, the output signal S3 of the OR gate 5 is
is inverted to a high level by a low-level inverter 14.

The above three input signals 81° 82 of the Nant gate 12,
As S3 becomes high level, the output signal of the Nant gate 12, that is, the write enable signal S4 becomes low level. This write enable signal S4 is inverted to zero by the inverter 15 and input to the clear input CLH of the D flip 70 knob 16.
The gate in the flip-flop is opened. As a result, the D flip-flop 16 is inverted by the inverter 17.
The write data signal S5 inputted to the clock input C is frequency-divided by two in the D flip-flop 16, and converted into write data signals WD and WD having opposite levels, respectively, and outputted from complementary outputs Q and Q.

These write data signals WD and WD are connected to the switching circuit 7.
The signal is guided to the head circuit 8 via the head circuit 8, where recording is performed.

Next, when the changeover switch 13 is turned on, each signal in the write control circuit 6 becomes as shown in FIG. 3(b).

In other words, the changeover switch 13 is turned on, and the power supply +■
By grounding the applied voltage, the switching signal S1 becomes low level. Therefore, even if the output signal of the inverter 14 due to the write protect signal S2 and the output signal S3 of the OR gate 5 becomes high level as described above, the write enable signal S4 which is the output signal of the Nant gate 12
is fixed at a high level.

High level write enable signal S4 is applied to inverter 1
Inverted to low level by 5, D flip 70 knob 1
6, the gate in the D flip-flop 16 is closed.

As a result, regardless of the input of the signal s5, the write data signals (2) and (W) are fixed at a high level and a low level, respectively, and no recording is performed.

In other words, recording is prohibited.

In the following operation, write protection and output signal S
3, as long as the switching signal S1 goes low, the write enable signal S4 output from the Nantes gate 12 goes high, and recording is prohibited. That is, regardless of whether the write process is processed or unprocessed, recording is prohibited when the changeover switch 13 is turned on.

Note that the playback operation with the above configuration is the same as the conventional one, so a description thereof will be omitted.

In the first embodiment above, a magnetic disk device was used as an example, but the above structure can be applied to other recording devices, and similar effects can be obtained by providing a control circuit similar to that described above.

Effects It is clear from the above explanation that according to the present invention, in a recording/reproducing device having both functions of recording and reproducing information,
Since we have provided a means to prohibit recording via a changeover switch, it is possible to prohibit recording without having to perform write protection processing on the recording medium side with an inexpensive and simple configuration. Destruction and loss of recorded information on a recording medium can be prevented. Moreover, this can be done by operating an extremely simple changeover switch.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating the configuration of an embodiment of the present invention;
Figure 2 is a block circuit diagram showing the detailed configuration of the write control circuit in Figure 1, and Figures 3 (a) and (b) are each part of the write control circuit in Figure 2 during recording and when recording is prohibited, respectively. FIG. 2 is a timing chart diagram showing signals of FIG. 6... Light control circuit 12... Nantes gate 13.
... Changeover switch 14, 15.17 ... Inverter 16 ... D flip-flop Sl ... Switching signal S2 ... Write protect signal S3 - OR gate output signal S4 ... Write enable signal S 5 iWD, WD...Light data signal patent applicant Canon Electronics Co., Ltd.

Claims (1)

[Claims] 1. A recording and reproducing apparatus capable of recording and reproducing information on a recording medium, characterized in that the recording and reproducing apparatus is provided with means for inhibiting recording via a changeover switch.