JPH04311801A - Disk inspection device - Google Patents

Abstract

PURPOSE:To obtain a high speed disk inspecting device with a simple and cheap structure and without using a computer, etc. CONSTITUTION:A rotary shaft of a disk rotating motor 2 rotating an inspected disk and a rotary shaft of a rotary encoder 3 are attached as one body. A pulse output signal of the rotary encoder 3 is connected to an input terminal of a counter circuit 4. An output signal of the counter circuit 4 is connected to an input terminal of a sensor drive motor driver 5. An output signal of the sensor drive motor driver 5 is connected to a sensor drive motor 6 and the rotation of the sensor drive motor 6 is converted to a linear motion with a sensor movement table 7 and an inspecting sensor 8 is moved in the radial direction of the inspected disk 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk inspection apparatus, and more particularly to a disk inspection apparatus for inspecting the recording characteristics, surface condition, mechanical properties, etc. of a magnetic disk or optical disk.

0002

[Prior Art] A conventional disk inspection device includes a disk rotation motor that rotates a disk to be inspected, a rotary encoder that is attached to the same shaft as the disk rotation motor and outputs pulse signals synchronized with the disk rotation, and a pulse signal of the rotary encoder. A counter circuit that counts the number of
It has means, such as a computer, for receiving the output of this counter circuit and outputting a drive command to a sensor drive motor that drives the inspection sensor section.

Generally, when inspecting the recording characteristics and mechanical properties of a single magnetic disk or optical disk, a test sensor, such as a write/read head of the magnetic disk or a micro-displacement meter, is placed at a certain point on the rotating disk, and the test sensor is fixed at one point on the rotating disk. After performing the inspection, the inspection sensor is moved by a certain amount in the radial direction of the disk, and inspection is performed for the next round, and this is repeated to complete the inspection of the entire disk surface.

[0004] However, in many cases, there are a plurality of inspection items, so one revolution of the disk is not enough to inspect one rotation, and several rotations are required. For this purpose, conventionally, after stopping the inspection sensor at a certain point on the disk and starting the inspection,
The output pulses of the rotary encoder are counted by a counter circuit, and the computer continues to monitor the output of the counter circuit to confirm that the specified rotation has been reached, and then outputs a drive command to the sensor drive motor to move the inspection sensor part to the next one. Move to inspection position.

[0005]

[Problems to be Solved by the Invention] This conventional disk inspection device requires a computer to monitor the disk rotation speed and issue drive commands to the sensor drive motor, so it is necessary to create a software program to control these operations. There is a problem in that wasted time occurs due to program operation time. Furthermore, since an interface circuit and a connecting cable are required for exchanging signals between the computer, the counter circuit, and the sensor drive motor, the device becomes complicated and expensive.

[0006]

[Means for Solving the Problems] A disk inspection apparatus of the present invention includes a disk rotation motor that rotates a disk to be inspected, and a rotary encoder that is attached to the same shaft as the disk rotation motor and outputs a pulse signal synchronized with the disk rotation. a counter circuit that inputs the pulse output signal of the rotary encoder, counts the signal, and outputs one pulse signal when a predetermined number is reached; and a test sensor unit that operates in synchronization with the output pulse signal of the counter circuit. It is equipped with a sensor drive motor to drive the sensor.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.

The rotating shaft of a disk rotation motor 2 that rotates the disk 1 to be inspected and the rotating shaft of a rotary encoder 3 are integrally attached, and the pulse output signal of the rotary encoder 3 is synchronized with the rotation of the disk 1 to be inspected. The pulse output signal of the rotary encoder 3 is sent to the counter circuit 4.
The output signal of the counter circuit 4 is connected to the input terminal of the sensor drive motor driver 5. The output signal of the sensor drive motor driver 5 is connected to the sensor drive motor 6, and the rotation of the sensor drive motor 6 is converted into linear motion by the sensor moving table 7, thereby moving the inspection sensor 8 in the radial direction of the disk 1 to be inspected.

Next, the operation will be explained in detail. For example, the pulse output signal of the rotary encoder 3 is
It is assumed that one pulse is output per rotation of the disk to be inspected in synchronization with the rotation of the disk. Further, if the number of revolutions required for testing one round of the disk 1 to be tested is n times, then the counter circuit 4
is set so that one pulse output is output for every (n+1) input pulses. This can be easily achieved by using the preset function of the counter circuit.

Therefore, as an example, an example of the operation when n=2 will be explained step by step using the timing diagram of FIG. and is applied to the input terminal of the sensor drive motor driver 5. When one pulse signal is applied to the input terminal, the sensor drive motor driver 5 provides the sensor drive motor 6 with a drive current that generates a drive force that rotates the rotating shaft of the sensor drive motor 6 in response to one pulse. Since the rotation of the rotation shaft of the sensor drive motor 6 is converted into linear motion by the sensor movement table 7,
In response to one pulse output signal from the counter circuit 4, the sensor moving table 7 moves by a track pitch Δt, and the inspection sensor 8 attached to the sensor moving table 7 is displaced by Δt in the radial direction of the disk 1 to be inspected.

Therefore, the inspection sensor 8 moves during the first of the three rotations of the disk 1 to be inspected, and during the next second rotation, inspection 1 is carried out in which several inspection items are carried out, and then the next three rotations are performed.
Inspection 2 is performed in which several other inspection items are carried out in rotation. By repeating this process, the entire surface of the disk to be inspected can be inspected.

0012

[Effects of the Invention] As explained above, the present invention allows the inspection sensor to move directly connected to the rotation system of the disk to be inspected without using a computer or the like, and performs all driving simply by controlling the disk rotation motor. Therefore, there is no need to create a program, and there is no dead time due to program operation time, and it is possible to realize a high-speed disk inspection device with a simple and inexpensive configuration. Furthermore, the movement of the inspection sensor is completely synchronized with the disk rotation, so even if you change the control method of the disk rotation motor, such as changing the rotation speed between the inner and outer circumferences, you do not need to change any other components. It also has the flexibility of being able to handle changes in the number of test items by simply changing the counter circuit.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a timing diagram showing an example of the operation of the present invention.

[Explanation of symbols]

1 Disk to be inspected 2 Disk rotation motor 3 Rotary encoder 4 Counter circuit 6 Sensor drive motor 8 Inspection sensor

Claims (1)

[Claims] 1. A disk rotation motor that rotates an inspection disk; a rotary encoder that is attached to the same axis as the disk rotation motor and outputs a pulse signal synchronized with the rotation of the disk; and a rotary encoder that receives the pulse output signal of the rotary encoder as input. The present invention is characterized by comprising a counter circuit that counts signals and outputs one pulse signal when a predetermined number is reached, and a sensor drive motor that drives the inspection sensor unit in synchronization with the output pulse signal of the counter circuit. Disc inspection equipment.