KR100257382B1 - Apparatus and method of testing cd-rom drive - Google Patents

Abstract

PURPOSE: A method and a device for checking a CD-ROM drive are provided to check a level and a frequency of a digital audio signal generated from the CD-ROM drive in order to check an operation of the CD-ROM drive. The method and device are provided to automatically check the performance of the CD-ROM drive. CONSTITUTION: A controller(70) plays a specific track of a CD-ROM drive, to read digital audio signals. A signal divider(42) divides the digital audio signals into signals of right/left channels. A digital analog converter(44) converts the divided digital audio signals into analog signals. The first and second filters(46,48) remove noise in the analog signals. A frequency checking unit(40) converts the analog signals into pulse. The first and second frequency detectors(58,60) measures frequencies of pulse, to decide whether the measured frequencies exist within a frequency range. If not, the CD-ROM drive is decided to be defective. If the measured signals exist within the frequency range, the first and second level checkers(72,74) check the level of inputted digital audio signals. If the level exists within a predetermined range, the CD-ROM drive is decided to be good. And if the level does not exits within the predetermined range, D-ROM drive is decided to be defective.

Description

CD-ROM drive test device and method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CD-ROM drive, and more particularly to a CD-ROM drive test apparatus for checking the level and frequency of digital audio signals generated from the drive to test the operation of the produced CD-ROM drive. It is about a method.

Hereinafter, a conventional CD-ROM drive test method will be described with reference to the accompanying drawings.

1 is a flowchart illustrating a conventional CD-ROM drive test method, which includes preparing a CD-ROM drive test (steps 10 to 18) and determining frequency / defect by measuring frequency and level ( 20 to 26 steps).

As shown in Fig. 1, one CD-ROM drive is selected in a line by a sampling method (step 10). After the tenth step, the selected CD-ROM drive is connected with a measurement instrument, for example an oscilloscope (step 12). After the twelfth step, DC voltages of +12 volts and +5 volts are applied to the connected CD-ROM drive (step 14). That is, connect the CD-ROM drive with the power supply. After the fourteenth step, the operator presses the tray open and stop buttons on the front of the CD-ROM drive to open the tray, insert a test disc in which a specific audio signal is recorded for inspection, and then open and close the tray again. And the stop button to close the tray (step 16). After the sixteenth step, the play / skip key on the front of the CD-ROM drive is pressed to move to the track of the disc on which the 1 KHz audio signal is recorded to output the digital audio signal. That is, a signal having a predetermined frequency is applied to the CD-ROM drive (step 18). After the eighteenth step, the operator reads the waveform displayed on the oscilloscope to read whether the output waveform of the digital audio signal output from the CD-ROM drive is normal (step 20). The level / frequency of the selected CD-ROM drive is determined by comparing the level of the frequency and the signal read in step 20 with the reference level (step 22). If the product is good, the test is repeatedly performed after sampling the new CD-ROM drive after sending the line later (step 26). However, if it is defective, the line is stopped and the inspected CD-ROM drive is disassembled to analyze and correct the cause of the defect, and then the line is started (step 24). After that, the new CD-ROM drive is sampled and the test is repeated.

In the conventional CD-ROM drive inspection method described above, the frequency and signal level of the digital audio signal of the CD-ROM drive are extracted and inspected visually by the operator. It was high, there was a problem that the production cost increases due to the increase in the number of workers.

An object of the present invention is to provide a CD-ROM drive tester that can automatically test the performance of the CD-ROM drive.

Another object of the present invention is to provide a CD-ROM drive test method performed by the CD-ROM drive test device.

1 is a flowchart for explaining a conventional CD-ROM drive test method.

2 is a block diagram of a CD-ROM drive test apparatus according to the present invention.

3 is a flowchart for explaining a CD-ROM drive test method according to the present invention.

4 (a) to 4 (e) are waveform diagrams of respective parts shown in FIG.

In order to achieve the above object, the CD-ROM drive test apparatus according to the present invention for inputting a test signal having a predetermined frequency and outputting a digital audio signal, the CD-ROM drive test apparatus according to the present invention is inputted to separate the channel, Frequency checking means for converting the separated signals into pulse forms, checking whether the frequency of the converted pulses is within a frequency range approximating the predetermined frequency, and outputting a first result signal corresponding to the inspected results; Level checking means for checking whether the level of the digital audio signal is within a predetermined range and outputting a second result signal corresponding to the checked result, and outputting a decision result signal in response to the first and second result signals. Input / output of the final test means and the determination result signal to enable / disable the CD-ROM drive. It is composed of a control means for determining a preferred.

In order to achieve the above object, the CD-ROM drive test method according to the present invention for testing a CD-ROM drive for inputting a test signal having a predetermined frequency and outputting a digital audio signal includes playing a specific track of the CD-ROM drive and performing digital operation. A signal reading step of reading an audio signal, a frequency measuring step of separating the digital audio signal for each channel, and converting the digital audio signal into an analog signal to measure frequencies of each channel, and a frequency at which the measured frequencies are close to the predetermined frequency A first judging step of judging whether it is within a range, a level measuring step of measuring a level of the digital audio signal if the measured frequencies are within the frequency range, and whether the measured level is within a predetermined range A second judging step of determining; If the level is within the predetermined range, the first judging step of determining that the CD-ROM drive is good and the level of the digital audio signal does not exist within the predetermined range, or the frequency of the digital audio signal exists within the frequency range Otherwise, it is preferable that the CD-ROM drive be made of a second determination step which determines that the CD-ROM drive is bad.

Hereinafter, the configuration and operation of a CD-ROM drive test method and apparatus according to the present invention will be described with reference to the accompanying drawings.

2 is a block diagram of a CD-ROM drive test apparatus according to the present invention, which includes a signal separation unit 42, a digital to analog converter (DAC) 44, first and second filters 46 and 48, first and second buffers 50 and 52, first and second comparators 54 and 56, first and second frequency check units 58 and 60, and inverted AND 62 The frequency checker 40, the first and second level checkers 72 and 74, the first exclusive OR 76, the low pass filter 78, and the second exclusive OR 80. It is composed of a level inspection unit 70, the final inspection unit 90 and the control unit 100 is composed of.

3 is a flowchart for explaining a CD-ROM drive test method according to the present invention, in which a digital audio signal is read (steps 200 and 202) by preparing for a test of the CD-ROM drive, Checking the frequency (steps 204 to 214), checking the level of the digital audio signal (steps 216 and 218) and taking steps corresponding to the test result (steps 220 and 222).

4 (a) to 4 (e) are waveform diagrams of respective parts shown in FIG.

The CD-ROM drive test apparatus according to the present invention automatically prepares to test the CD-ROM drive in order to test the CD-ROM drive (step 200). That is, the pallet which loads the CD-ROM drive on the conveyor is detected by the detection sensor. If the pallet is detected by the detection sensor, the control unit 100 raises the stopper and lifts the pallet up. Stop and determine position. When the position is determined, the controller 100 supplies power to the CD-ROM drive, opens a tray of the CD-R0M drive, loads a test disk, and closes the tray. When the above-described step 200 is completed, the controller 100 controls the CD-ROM drive to play a specific track of the test disc to read the digital audio signal (step 202).

The signal separation unit 42 shown in FIG. 2 inputs the digital audio signal output from the CD-ROM drive through the input terminal IN to decode the two signals of the left and right channels for each channel and decodes them. 4 The waveform shown in (a) is output (step 204). After step 204, the digital analog converter 44 converts two digital audio signals separated into a left channel and a right channel into an analog signal and outputs the signal shown in FIG. 4 (b) (step 206). After step 206, each of the first and second filters 46 and 48 has a certain amount of noise in the output of the DAC 44. In order to eliminate this, each of the two signals is passed through 1 KHz. After the noise is removed, the signal shown in FIG. 4 (c) from which the noise is removed is output (step 208).

After the step 208, the first and second buffers 50 and 52 are buffered to drive the signal so that the signal from which the noise is removed in the first and second filters 46 and 48 is strong against noise, The buffered signal is input to the first and second comparators 54 and 56 and compared with a predetermined level, and converted into a pulse wave form shown in FIG. 4 (d) (step 210). The first and second frequency detectors 58 and 60 allow for detecting a frequency range of 990 Hz to 1100 Hz when the digital audio signal read out from the test disc is 1 KHz. That is, after step 210, the first and second frequency detectors 58 and 60 measure the frequency of the pulse wave (step 212), and determine if the measured frequency is within a frequency within the range (second). Step 214). If the measured frequency is a frequency within the region, a low level is output to indicate that it is normal. The inverted AND 62 performs an inverted OR on the outputs of the first and second frequency detectors 58 and 60, and outputs the ORed result. That is, if the signals of the left and right channels are both frequencies within the region, the first result signal of the high level is output, otherwise the first result signal of the low level is output.

On the other hand, the first level inspecting unit 72 measures the level of the digital audio signal input through the input terminal IN (step 216), and checks whether it is less than the maximum value of the predetermined level section (step 218). The level inspecting unit 74 measures the level of the digital audio signal (step 216) and checks whether or not the minimum value of the predetermined level section is equal (step 218). If there is a level of the digital audio signal in the predetermined level section, the exclusive OR 76 outputs a high level signal, otherwise outputs a low level signal. The low pass filter 78 serves to remove the signal component shown in FIG. 4 (e), and the output of the low pass filter 78 is input to an exclusive OR 80, which is exclusive OR with a reference potential. The second result signal is output to the final inspection unit 90.

The final inspection unit 90 inputs the first result signal output from the inverted logical sum 62 and the second result signal output from the second exclusive logical sum 80 so that the first result signal is at a high level and the second result is output. If the signal is high, it is determined that the tested CD-ROM drive is good, and the test disc is taken out from the CD-ROM drive, the connected line is disconnected, and the stopper is turned off to transfer the pallet to the next process (step 220). However, when the first result signal or the second result signal is at the low level, the CD-ROM drive is determined to be in a bad state, and the defect is displayed on the pallet so that it can be taken out in the step of taking out the defect (step 222).

As described above, the CD-ROM drive inspection apparatus and method according to the present invention improves defect detection by 100% by applying an automatic inspection system to a line, prevents field claims in advance, and reduces workforce. There is.

Claims (7)

A CD-ROM drive test apparatus for testing a CD-ROM drive that inputs a test signal having a predetermined frequency and outputs a digital audio signal. The digital audio signal is input and separated for each channel, the separated signals are converted into pulse forms, and whether the frequency of the converted pulses is within a frequency range approximating the predetermined frequency, and the first corresponding to the inspected results. Frequency checking means for outputting a result signal; Level checking means for checking whether the level of the input digital audio signal is within a predetermined range, and outputting a second result signal corresponding to the checked result; Final inspection means for outputting a determination result signal in response to the first and second result signals; And And a control means for inputting the determination result signal to determine the quantity / defect of the CD-ROM drive. The method of claim 1, wherein the frequency checking means Signal separation means for inputting the digital audio signal from the CD-ROM drive and separating the digital audio signal into a left channel signal and a right channel signal; Digital / analog conversion means for inputting the output of the signal separation means and converting the signal into an analog signal; First and second filtering means for removing noise of the left channel signal and the right channel signal respectively output from the digital / analog conversion means; First and second buffers configured to input and buffer the outputs of the first and second filtering means, respectively; First and second signal converting means for converting analog signals output from the first and second buffers into signals in pulse form, respectively; Measuring the frequencies of the signals output from the first and second signal conversion means, respectively, and checking whether the frequencies of the converted pulses are each within a frequency range approximating the predetermined frequency, and checking the first and second results First and second frequency inspection means for outputting the respective signals; And And a first result signal generating means for outputting the first result signal corresponding to the first and second results. The method according to claim 1 or 2, wherein the level checking means First level checking means for checking whether a level of the digital audio signal is equal to or higher than a minimum level of the predetermined range; Second level checking means for checking whether a level of the digital audio signal is equal to or less than a maximum level of the predetermined range; And And a second result signal generating means for generating the second result signal in response to a result inspected by the first and second level inspection means. In the CD-ROM drive test method for testing a CD-ROM drive for outputting a digital audio signal by inputting a test signal having a predetermined frequency, A signal reading step of reading a digital audio signal by playing a specific track of the CD-ROM drive; A frequency measuring step of separating the digital audio signal for each channel and converting the digital audio signal into an analog signal to measure frequencies of each channel; A first judging step of determining whether the measured frequencies are within a frequency range close to the predetermined frequency; A level measuring step of measuring a level of the digital audio signal if the measured frequencies are within the frequency range; A second judging step of judging whether the measured level exists within a predetermined range; A first judging step of determining that the CD-ROM drive is good if the level of the digital audio signal is within the predetermined range; And And if the level of the digital audio signal does not exist in the predetermined range, or if the frequency of the digital audio signal does not exist in the frequency range, a second determination step for determining that the CD-ROM drive is bad. How to check CD-ROM drive. The method of claim 4, wherein the frequency measuring step Dividing the digital audio signal by left and right channels; Converting the separated signals into analog signals; Removing noise of the analog signals; Converting the waveforms of the noise-removed analog signals into pulse forms; And And measuring each frequency of the pulse-shaped signals. In the CD-ROM drive test method for testing a CD-ROM drive for outputting a digital audio signal by inputting a test signal having a predetermined frequency, A level measuring step of measuring a level of the digital audio signal; A first judging step of judging whether the measured level exists within a predetermined range; A signal reading step of reading a digital audio signal by playing a specific track of the CD-ROM drive when the measured level is within the predetermined range; A frequency measuring step of separating the digital audio signal for each channel and converting the digital audio signal into an analog signal to measure frequencies of each channel; A second judging step of determining whether the measured frequencies are within a frequency range close to the predetermined frequency; A first determination step of determining that the CD-ROM drive is good if the frequency of the digital audio signal is within the frequency range; And And if the level of the digital audio signal does not exist in the predetermined range, or if the frequency of the digital audio signal does not exist in the frequency range, a second determination step for determining that the CD-ROM drive is bad. How to check CD-ROM drive. The method of claim 6, wherein the frequency measuring step Dividing the digital audio signal by left and right channels; Converting the separated signals into analog signals; Removing noise of the analog signals; Converting the waveforms of the noise-removed analog signals into pulse forms; And And measuring each frequency of the pulse-shaped signals.

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