JP2537490B2 - Magnetic disk drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive device, and more particularly to a magnetic disk drive device having an improved detection circuit for a magnetic disk function.

[Prior Art] Conventionally, a magnetic disk drive detection circuit of a magnetic disk drive device, for example, a write protection function detection circuit, always detects the presence or absence of a write protect notch of a magnetic disk drive when power is supplied to the magnetic disk drive device. The circuit was working to detect.

[Problems to be Solved by the Invention] The structure described above has a drawback in that current is consumed even when it is not time to detect the function of the magnetic disk, resulting in wasting power.

[Means for Solving the Problems] In the present invention, in order to solve the above problems,
In the magnetic disk drive device, a first sensor for detecting the presence or absence of the magnetic disk (11), a second sensor (13, 14) for detecting the state (12) of the magnetic disk, and a second sensor A function detection circuit (1) for detecting the function of the magnetic disk based on the output, a current (5) for operating the function detection circuit, and a magnetic field from the state indicating the absence of the magnetic disk of the output signal of the first sensor. A pulse generating circuit (4) that outputs a pulse in response to a change to a state indicating that a disk is present, and power is supplied from the power source to the function detecting circuit only while the pulse of the pulse generating circuit is being output. Is adopted.

[Operation] According to such a configuration, the state of the signal of the first sensor changes when the magnetic disk is newly mounted in the device,
In response to this, the pulse generation circuit outputs a pulse, and power is supplied from the power supply to the function detection circuit only while the pulse is output, and the function of the magnetic disk is detected based on the output of the second sensor. .

[Examples] Hereinafter, details of the present invention will be described based on Examples shown in the drawings.

1 to 4 explain one embodiment of the present invention, and FIGS. 3 and 4 show a magnetic disk and a magnetic disk function detecting means. In the figure, 11 is a magnetic disk, and a notch 12 indicating whether or not there is a write protect function is formed in a part of the jacket of the magnetic disk. 13,14
Indicates a photocoupler connected to the write protect detection circuit, which is provided above and below the magnetic disk insertion path on the apparatus main body side.

 FIG. 1 shows a block diagram of the control circuit.

A reference numeral 1 in FIG. 1 denotes a write protect function detection circuit, which is connected to the write protect output holding circuit 2, and this circuit is connected to the read / write control circuit 3.

A magnetic disk presence / absence detection circuit 4 is connected to the write protect output holding circuit 2.

 Reference numeral 5 indicates a power source.

Next, the operation of this embodiment configured as described above will be described.

First, when the magnetic disk 1 is inserted into the magnetic disk drive, an output as shown in FIGS. 1 and 2A is obtained at the input of the magnetic disk presence / absence detection circuit 4, for example, as a photocoupler output. This is converted into pulse outputs as shown in (B) and (C) in the magnetic disk presence / absence detection circuit 4.

When the power supply 5 for the write protect detection circuit 1 is operated by this detection output (B), a current flows in the write protection detection circuit 1 only when the detection output (B) is ON, and the current is otherwise OFF. You can

On the other hand, the write protect detection circuit 1 is supplied with the write protect detection output shown by (E) from the photocoupler of FIG. 4, and when the power is turned on for a certain section by the output (B). The output signal (D) is output. The write protect output holding circuit 2 detects the input of the output (D) when the output (B) is input, holds the state at that time, and outputs the held output (F). This state is maintained until the magnetic disk presence / absence input is "none", that is, until the magnetic disk is removed.

When the magnetic disk is inserted again, the valid state of the output (D) is detected and held in synchronization with the output (B) at the timing as described above.

In this way, the power is turned on only when the write protect function should be detected, and wasteful power consumption can be prevented.

The input (A) of the presence / absence of the magnetic disk may be a state in which the magnetic disk is not only attached / detached by the disk detection photocoupler but also clamped and stably read / written, that is, a so-called "Ready" output.

Also, with a magnetic disk release output such as output (C),
The write protect output holding circuit 2 may be reset, or the output (B) alone may be used to make the determination at all times when the magnetic disk is mounted.

As for the magnetic disk function, in addition to write protection, the 3.5-inch magnetic disk has high-density media /
It is conceivable that the magnetic disk itself may be provided with various functions such as detection of a normal density medium, but it can also be applied to such a case.

[Effect] As is apparent from the above description, according to the magnetic disk drive device of the present invention, the first sensor for detecting the presence or absence of the magnetic disk (11) and the state (12) of the magnetic disk are detected. A second sensor (13, 14), a function detection circuit (1) for detecting the function of the magnetic disk based on the output of the second sensor, a power supply (5) for operating the function detection circuit, A pulse generation circuit (4) for outputting a pulse in response to a change in the output signal of the first sensor from the state indicating the absence of the magnetic disk to the state indicating the presence of the magnetic disk; Since the configuration is such that the power is supplied from the power source to the function detection circuit only while the magnetic disk is being output, a change in the output signal of the first sensor can be prevented when the magnetic disk is newly mounted in the device. According to the pulse A pulse is output from the generation circuit, and power can be supplied from the power supply to the function detection circuit only while the pulse is output, so that the function of the magnetic disk can be detected based on the output of the second sensor. It is possible to prevent wasteful power consumption of the circuit and reduce power consumption. In addition, the excellent effect that the control of the power supply from the power supply to the function detection circuit can be performed very easily by the pulse is obtained.

[Brief description of drawings]

1 is a block diagram of a control circuit, FIGS. 2A to 2F are timing charts for explaining the operation, and FIG. 3 is a plan view of a magnetic disk. FIG. 4 and FIG. 4 are explanatory views of means for detecting a notch in the magnetic disk. 1 ... Write protect detection circuit 2 ... Write protect output holding circuit 3 ... Read / write control circuit 4 ... Magnetic disk presence / absence detection circuit 5 ... Write protect detection power supply

Claims (1)

(57) [Claims] 1. A first for detecting the presence or absence of a magnetic disk (11)
Sensor, a second sensor (13, 14) for detecting the state (12) of the magnetic disk, and a function detection circuit (1) for detecting the function of the magnetic disk based on the output of the second sensor. A power source (5) for operating the function detection circuit, and a pulse generation circuit for outputting a pulse in response to a change in the output signal of the first sensor from a state showing no magnetic disk to a state showing magnetic disk present. (4), and the magnetic disk drive device is characterized in that power is supplied from the power supply to the function detection circuit only while the pulse of the pulse generation circuit is being output.