JPH0464901A - Defect detection output measuring instrument - Google Patents

Abstract

PURPOSE:To obtain a reference waveform of high reproducibility to perform highly precise measurement by using an arbitrary waveform generator for the reference defect waveform signal which measures the defect detection output of a medium defect detector. CONSTITUTION:An arbitrary waveform generator 3 outputs a reference defect waveform signal 10 and outputs a waveform output synchronizing signal 11 synchronized with the output of this signal to a defect detecting circuit control part 2. The control part 2 detects a defect detection signal, which is outputted at the time of detecting a defect by a medium defect detecting circuit, and the signal 11 outputted from the generator 3; and in accordance with this detection condition, a system control part 1 obtains the defect detection rate of a medium defect detecting circuit to a defect detection slice level 12 given to the medium defect detecting circuit at present with respect to the signal 10 outputted at present. The control part 1 automatically successively changes and gives the value of the level 12 to the control part 2 to obtain the defect detection rate of the medium defect detecting circuit. A defect detection output curve is obtained from the result.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a defect detection power measurement device, and particularly to a defect detection power measurement device that automatically measures the defect detection output of a medium defect detection circuit that detects defective portions of a recording medium. Concerning a measuring device.

[Conventional technology]

Conventionally, this type of defect detection power measuring device does not exist, and when measuring the defect detection power of a medium defect detection circuit, defects in a recording medium mounted in a storage device are used as a reference defect waveform that is the basis of measurement. Using the readout waveform of the section, all work was done manually to determine changes in the defect detection rate with respect to changes in the slice level applied to the medium defect detection circuit.

[Problem to be solved by the invention]

In measuring the defect detection power of the conventional medium defect detection circuit described above, the readout waveform of the defective part of the recording medium mounted on the storage device is used as the reference defect waveform that is the basis of measurement. Each time a defective waveform is read, the shape of the waveform is slightly different, and when rewriting is performed, it is rare that a waveform with the exact same shape is read out due to the timing shift of writing, so the reference waveform for measurement is The reproducibility of the medium defect detection circuit is low, making it impossible to measure with high precision.In addition, instructions from the controller that controls the storage device are required to control the output of the reference defect waveform. The disadvantage is that the system required to do so is large-scale.

In addition, in order to obtain a defect detection power curve, it is necessary to vary the slice level given to the medium defect detection circuit several times and perform detection measurements of several to ten or more slices each time to obtain the detection rate, which is done manually each time. The disadvantage is that it takes a lot of time and effort to operate and measure.

[Means to solve the problem]

A defect detecting power measuring device of the present invention is a defect detecting power measuring device for a medium defect detecting circuit that records information on a recording medium and reads out the information to detect defects in the recording medium. a defect detection circuit control section that controls a detection slice level and senses a defect detection signal output by the medium defect detection circuit; an arbitrary waveform generator that reproduces a readout signal of the medium defect portion; and the arbitrary waveform generator. The system controller includes a system controller that performs various controls such as starting and stopping the output of the waveform signal to be output, selecting the type of waveform, and controlling the defect detection circuit controller.

〔Example〕

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 defect detection power measuring device shown in FIG. 1 is composed of a system control device 1, a defect detection circuit control section 2, and an arbitrary waveform generator 3. A medium defect detection circuit (not shown), which is a controlled circuit, is connected to each of the arbitrary waveform generators 3 of the defect detection circuit control section 2.

Next, the functions and operations of this embodiment will be explained.

The system control section 1 can perform various controls including exchanging data with the defect detection circuit control section 2, and various controls on signals output from the arbitrary waveform generator 3.

When measuring the detection output of a medium defect detection circuit (not shown), the system control unit 1 instructs the arbitrary waveform generator 3 to know the defect level that has a waveform equivalent to the readout waveform of the actual medium defect portion. It commands the output of the reference defect waveform signal 10, and also instructs the defect detection circuit control unit 2 to set the defect detection slice level 12 to be applied to the medium defect detection circuit and to start detecting the defect detection signal 13.

The arbitrary waveform generator 3 outputs a reference defect waveform signal 10 and also outputs a waveform output synchronization signal 11 synchronized with the output of the reference defect waveform signal 10 to the defect detection circuit control section 2. The defect detection circuit control unit 2 includes a medium defect detection circuit (not shown).
detects the defect detection signal 13 outputted when detecting a defect and the waveform output synchronization signal 11 outputted from the arbitrary waveform generator 3, and based on the detection status, the system control unit 1 detects the currently output reference defect waveform signal 10. Find the defect detection rate of the medium defect detection circuit for the defect detection slice level 12 currently given to the medium defect detection circuit.

The system control unit 1 automatically changes and supplies the value of the defect detection slice level 12 to the defect detection circuit control unit 2 in sequence, and similarly calculates the defect detection rate of the medium defect detection circuit for each defect detection slice level each time. .

From the results, a defect detection power curve as shown in FIG. 2 is determined. In FIG. 2, the horizontal axis represents the defect detection slice level set in the defect detection circuit, and the vertical axis represents the defect detection rate for each defect detection slice level.

〔Effect of the invention〕

As explained above, the defect detecting power measuring device of the present invention does not use the readout waveform of the medium defect portion of the actual recording medium as the reference defect waveform signal for measuring the defect detecting power of the medium defect detecting device. By using an arbitrary waveform generator, it is possible to obtain a reference waveform with higher reproducibility and to perform highly accurate measurements, and to control the output of the reference defect waveform, there is no need for a controller to control the storage device. The system for measuring the detection power is small, and the defect detection slice level applied to the medium defect detection circuit is automatically changed and the detection rate is calculated in order to obtain the defect detection power curve. This method has the advantage that measurements can be obtained without the time and effort required in the conventional method.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a graph showing a defect detection power curve showing measurement results of defect detection power. DESCRIPTION OF SYMBOLS 1... System control part, 2... Defect detection circuit control part, 3... Arbitrary waveform generator, 10... Reference defect waveform signal, 11... Waveform output synchronization signal, 12... Defect Detection slice level, 13...defect detection signal.

Claims (1)

[Claims] In a defect detection power measuring device for a medium defect detection circuit that records information on a recording medium and reads out the information to detect defects in the recording medium, the defect detection slice level of the medium defect detection circuit is controlled and the defect detection ability of the medium defect detection circuit is controlled. a defect detection circuit control unit that senses a defect detection signal output by the detection circuit;
an arbitrary waveform generator that reproduces a readout signal of the medium defective portion; and a start of outputting a waveform signal outputted by the arbitrary waveform generator;
A defect detection power measuring device comprising: a system control section that performs various controls such as stopping and selection of waveform type, and controlling the defect detection circuit control section.