JP4064271B2 - Optical pickup inspection device and inspection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical pickup inspection apparatus and inspection method for inspecting an optical pickup by recording data on a recordable optical disk DK such as a CD and a DVD and reproducing the data recorded on the optical disk.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an inspection apparatus that inspects an optical pickup by recording inspection data on an optical disc and then reproducing the recorded data and evaluating the reproduced data is known (see Patent Document 1 below). In this inspection apparatus, the irradiation position of the laser beam by the optical pickup is initially moved to an unrecorded portion of the optical disk, and then the tracking servo is turned off and then turned on again. Record. After the inspection data is recorded, the tracking servo is turned off and then turned on again to reproduce the recorded inspection data. In Patent Document 1, the address of the optical disk is read, and when the read address reaches a predetermined address, the irradiation position of the laser beam is jumped to the inner peripheral position, and the characteristics at the same position are always reproduced. It also describes that the inspection can be performed with good quality.
[0003]
[Patent Document 1]
JP 2002-190134 A
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional apparatus, when a write-once (recordable only once) optical disk is used, when the irradiation position of the laser beam is moved before recording the inspection data, the recording position of the inspection data is In order to avoid overlapping, it is necessary to move the irradiation position of the laser beam from the previous recording position to a position having a margin. This means that an unrecorded area for inspection data is provided on the optical disk, and the recordable area of the optical disk is consumed. Even when an always writable optical disk is used, recording of the inspection data is repeatedly performed to deteriorate the accuracy of recording and reproduction of the inspection data. In this case as well, the recordable area of the optical disk is consumed. Is done.
[0005]
In addition, when an optical disc capable of detecting the address of the optical disc is used, it may be possible to detect the address and record inspection data so that an unrecorded area is not provided on the optical disc using this detected address. But the problem of address detection mistakes remains. As a countermeasure against this address detection error, it is conceivable to confirm a plurality of times at the time of address seeking. However, if this is done, the inspection time becomes longer and the inspection efficiency of the optical pickup deteriorates. As another countermeasure against an address detection error, it is conceivable to provide an unrecorded area for inspection data as described above on the optical disc. In this case, the recordable area is consumed as described above.
[0006]
Further, in the conventional optical pickup inspection apparatus, if there is a defect such as a scratch on the optical disk to be used, it cannot be distinguished from a defective optical pickup, and the optical pickup cannot be inspected accurately.
[0007]
Furthermore, depending on the optical pickup, the evaluation result of the reproduction signal may differ depending on whether the data is recorded on the adjacent track or not. However, in the conventional optical pickup inspection apparatus, since the reproduction signal is evaluated regardless of the presence / absence of data in the adjacent track, the optical pickup is not accurately inspected.
[0008]
SUMMARY OF THE INVENTION
The present invention has been made to cope with the above-described problems. The purpose of the present invention is to rotate an optical disk, record inspection data on the optical disk by an optical pickup, and reproduce the inspection data recorded on the optical disk by the optical pickup. Then, in the optical pickup inspection apparatus and inspection method for inspecting the optical pickup by evaluating the reproduction signal by the reproduction, an optical disk is used effectively and the inspection of the optical pickup can be performed accurately.
[0009]
In order to achieve the above object, the present invention is characterized in that the irradiation position of the laser beam by the optical pickup is initially moved to a position slightly before the recording start position of the inspection data on the optical disc, and the irradiation position of the laser beam is determined. After the initial movement, the presence of the recording data on the optical disk is confirmed based on the reproduction signal of the recording data by the optical pickup. Then, when the presence of the recording data on the optical disc is not confirmed by the confirmation, recording of the inspection data on the optical disc by the optical pickup is started.
[0010]
In this case, the recording data is confirmed by, for example, jumping by one track in order to return the irradiation position of the laser beam by the optical pickup to the position before one rotation every time the optical disk makes one rotation, and on the track after the jump. The presence of the recording data is confirmed by the presence / absence of a reproduction signal of the recording data. When the presence of the recording data is confirmed by the confirmation, it is preferable that the irradiation position of the laser beam by the optical pickup is jumped by one track in the same direction as the moving direction of the irradiation position of the initial laser beam.
[0011]
According to this, since the inspection data is reliably recorded from the track next to the track on which the data has already been recorded, it is possible to prevent the recordable area of the optical disk from being consumed. As a result, according to the present invention, the optical disk is effectively used for the inspection of the optical pickup.
[0012]
  Another feature of the present invention is that the irradiation position of the laser beam on the optical disk by the optical pickup is jumped by one track, and the optical pickup is controlled to record the inspection data on the track after the jump. After recording the inspection data, the irradiation position of the laser beam by the optical pickup is jumped to the track on which the inspection data is recorded, and the inspection data recorded on the track after the jump is controlled by controlling the optical pickup. Play for signal evaluation. Then, the recording operation and the reproducing operation of such inspection data are repeatedly performed.In this case as well, the irradiation position of the laser beam by the optical pickup is initially moved to a position slightly before the recording start position of the inspection data on the optical disk, and recording on the optical disk is performed based on the reproduction signal of the recording data by the optical pickup. Check for the existence of data. Then, when the confirmation does not confirm the existence of the recording data on the optical disc, the initial recording of the inspection data on the optical disc by the optical pickup is started.
[0013]
  According to this, since the inspection data is reproduced for each track, it is possible to distinguish between defects such as scratches on the optical disk to be used and optical pickup defects. As a result, according to the other feature of the present invention, the optical pickup is accurately inspected.Further, by preventing the unrecorded area from being consumed as described above, the optical disk used for the inspection of the optical pickup can be effectively used.
[0014]
  Another feature of the present invention is that the optical pickup is controlled to record the inspection data continuously on a plurality of tracks of the optical disk. Thereafter, the optical pickup is controlled to reproduce the recorded inspection data for a plurality of tracks one track at a time for evaluation of a reproduction signal.In this case as well, the irradiation position of the laser beam by the optical pickup is initially moved to a position slightly before the recording start position of the inspection data on the optical disk, and recording on the optical disk is performed based on the reproduction signal of the recording data by the optical pickup. Check for the existence of data. Then, when the confirmation does not confirm the existence of the recording data on the optical disc, the initial recording of the inspection data on the optical disc by the optical pickup is started.
[0015]
In this case, in the reproduction control, for example, every time the inspection data is reproduced for one track from the optical disk by jumping the irradiation position of the laser beam by the optical pickup to the track on which the recording of the inspection data is started, It is preferable to jump the laser beam irradiation position by one track in a direction opposite to the jump direction by the jump for starting reproduction.
[0016]
  Also by this, since the inspection data is reproduced for each track, it is possible to distinguish between defects such as scratches on the optical disk to be used and optical pickup defects. As a result, according to the other features of the present invention, the optical pickup is accurately inspected.Further, by preventing the unrecorded area from being consumed as described above, the optical disk used for the inspection of the optical pickup can be effectively used.
[0019]
Another feature of the present invention is that the optical pickup is controlled to record inspection data on one track of the optical disc, and the optical pickup is controlled to reproduce the recorded inspection data for evaluation of a reproduction signal. . Thereafter, the optical pickup is controlled to record data on the tracks of the optical disk positioned on both sides of the track on which the inspection data is recorded, and then the optical pickup is controlled to record the inspection data recorded on the reproduced track. Is reproduced again for evaluation of the reproduction signal.
[0020]
According to this, the inspection data is reproduced by distinguishing between the case where the data is recorded in the adjacent track and the case where the data is not recorded. As a result, the optical pickup is inspected in consideration of the presence / absence of data in adjacent tracks, so that the optical pickup is accurately inspected.
[0021]
Another feature of the present invention is that, in the inspection of the optical pickup considering the presence or absence of the data of the adjacent track, the irradiation position of the laser beam by the optical pickup is slightly before the recording start position of the inspection data on the optical disc. After confirming that there is no recording data in at least three consecutive tracks on the optical disk based on the reproduction signal of the recording data by the optical pickup, the center of the three tracks where there is no recording data is moved. It is preferable to record inspection data on a track.
[0022]
Thus, according to the present invention, in addition to the accurate inspection of the optical pickup according to the presence / absence of data of the adjacent track, the optical disc used for the inspection of the optical pickup is effectively prevented by preventing the consumption of the unrecorded area described above. It will also be used.
[0023]
Embodiment
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an entire optical pickup inspection apparatus together with an optical pickup to be inspected.
[0024]
This inspection apparatus includes a spindle motor 11 having a built-in encoder 11a. The spindle motor 11 is driven and controlled by the spindle motor control circuit 12, and rotationally drives the support table 13 on which the optical disk DK is assembled. The encoder 11a detects the rotation of the spindle motor 11, that is, the rotation of the support table 13 (optical disk DK). As shown in FIG. 11, every time the rotation position of the support table 13 (optical disk DK) reaches the reference rotation position. Rotation signal φ consisting of an index signal INDEX that is a reference signal and a pulse train signal that repeats a high level and a low level by a predetermined minute rotation angle_A, Φ_BIs output. These rotation signals φ_A, Φ_BAre shifted from each other by π / 2. These signals INDEX, φ_A, Φ_BIs supplied to the timing determination circuit 54 and the computer device 70. The index signal INDEX is also supplied to the first jump signal generation circuit 51.
[0025]
The spindle motor 11 is driven in the radial direction of the optical disk DK by a feed mechanism including a feed motor 14, a screw rod 15 and a support member 16 together with the encoder 11 a and the support table 13. The feed motor 14 is rotationally controlled by the sled servo circuit 17 to rotate the screw rod 15. The screw rod 15 is screwed into a nut (not shown) fixed to the support member 16. The screw rod 15, the support member 16, and the nut constitute a screw mechanism. Due to the rotation of the feed motor 14, the support member 16 is displaced together with the spindle motor 11 and the like in the axial direction of the screw rod 15, that is, in the radial direction of the optical disk DK.
[0026]
The feed motor 14 also includes an encoder 14a similar to the encoder 11a described above. This encoder 14a also has an index signal INDEX and a rotation signal φ._A, Φ_BIs output to the sled servo circuit 17 and the computer device 70.
[0027]
Here, the optical pickup 20 which is an inspection target assembled in the inspection apparatus will be described. The optical pickup 20 records data on a recordable optical disc DK such as a CD and a DVD, and reproduces data recorded on the optical disc DK. The optical pickup 20 includes a laser light source 21, a collimating lens (for example, a compound with a grating lens) 22, a polarizing beam splitter 23, a quarter wavelength plate 24, an objective lens 25, a condensing lens 26, a cylindrical lens 27, and a quadrant photo detector. 28. In this optical pickup 20, the laser light from the laser light source 21 is irradiated onto the optical disk DK via the collimating lens 22, the polarization beam splitter 23, the quarter wavelength plate 24, and the objective lens 25. Is received by a four-divided photodetector 28 through an objective lens 25, a quarter-wave plate 24, a polarizing beam splitter 23, a condenser lens 26, and a cylindrical lens 27, and light reception indicating the signal recording state of the optical disc DK. A signal is output.
[0028]
In this case, as shown in FIG. 2, the four-divided photodetector 28 includes four photodetector elements 28a, 28b, 28c, and 28d arranged in a plane orthogonal to the optical axis of the reflected light from the optical disk DK. These four photodetector elements 28a, 28b, 28c, and 28d are formed in the same square shape divided by each dividing line, and receive detection signals A, B, C, and D proportional to the amount of received light, respectively. Output as a received light signal. The direction connecting the photodetector elements 28a and 28d (same as the direction connecting the photodetector elements 28b and 28c) corresponds to the radial direction of the optical disc DK.
[0029]
A laser drive circuit 31 for driving the laser light source 21 is connected to the laser light source 21. A laser power setting circuit 32 and a recording signal generation circuit 33 are connected to the laser drive circuit 31. The laser power setting circuit 32 controls the laser driving circuit 31 in accordance with a command from the computer device 70 to control the operation and stop of the laser light source 21, and the laser emission power at the time of operation is a high power for recording. And switch to low power for playback. The recording signal generation circuit 33 generates a recording signal corresponding to the inspection data from the computer device 70 in response to a command from the computer device 70, and outputs the recording signal to the laser driving circuit 31. The light source 21 is turned on / off according to the recording signal.
[0030]
Detection signals A, B, C, and D by the photodetector elements 28a, 28b, 28c, and 28d of the quadrant photodetector 28 are supplied to the focus error signal generation circuit 42 and the tracking error signal generation circuit 43 through the HF signal amplification circuit 41. The The focus error signal generation circuit 42 generates a focus error signal by the astigmatism method that represents a value (A + C) − (B + D) obtained by subtracting the sum B + D of the detection signals B and D from the sum A + C of the detection signals A and C. Then, the error signal is supplied to the focus servo circuit 44. The focus servo circuit 44 supplies this focus error signal to the drive circuit 45, and performs focus servo control of the focus actuator 29a for driving the objective lens 25 in the optical axis direction. Thus, the focal point of the laser beam is controlled so as to follow the recording layer of the optical disc DK.
[0031]
The tracking error signal generation circuit 43 subtracts the sum (C + D) of the detection signals C and D from the photodetector elements 28c and 28d from the sum A + B of the detection signals A and B from the photodetector elements 28a and 28b (A + B) −. A tracking error signal representing (C + D) is supplied to the tracking servo circuit 46. The tracking servo circuit 46 supplies this tracking error signal to the drive circuit 48 via the adder 47, and performs tracking servo control on the tracking actuator 29b for driving the objective lens 25 in the tracking direction (the radial direction of the optical disk DK). To do. Thereby, the irradiation position of the laser beam on the optical disk DK is controlled so as to follow the track while vibrating in the radial direction of the optical disk DK.
[0032]
The output of the adder 47 is also supplied to the thread servo circuit 17. The thread servo circuit 17 includes a DC component extraction circuit that extracts a DC component from the input signal, and servo-controls the feed motor 14 so that the extracted DC component becomes “0”. Therefore, the optical disk DK moves relative to the objective lens 25 in the radial direction together with the spindle motor 11 and the support table 13. As a result, while the feed motor 14 changes the relative position between the objective lens 25 and the optical disk DK large and slowly, the track actuator 29b always vibrates the objective lens 25 about the neutral position, so that the laser beam for the optical disk DK is obtained. The irradiation position is controlled so as to accurately follow the track.
[0033]
The thread servo circuit 17 also includes an index signal INDEX and a rotation signal φ detected by the encoder 14a._A, Φ_BIs also connected to the computer device 70. The thread servo circuit 17 receives the index signal INDEX and the rotation signal φ in response to an instruction from the computer device 70._A, Φ_BIs used to move the irradiation position of the laser beam by the indicated amount in the radial direction of the optical disk DK.
[0034]
The tracking error signal from the tracking error signal generation circuit 43 is also supplied to the spindle motor control circuit 12 via the band pass filter 49. The band pass filter 49 extracts a wobble signal from the tracking error signal. Using this wobble signal, the spindle motor control circuit 12 controls the rotation of the spindle motor 11 so that the linear velocity at the irradiation position of the laser beam on the optical disk DK is always constant. The wobble signal is obtained because the track on the optical disk DK is microscopically waved in a sine wave shape in the radial direction for the purpose of controlling the rotation of the spindle motor 11 at a constant linear velocity. It is what The wobble signal is, for example, a sine wave signal of 22.05 kHz for CD and 150 kHz for DVD.
[0035]
The inspection apparatus also includes first, second, and third jump signal generation circuits 51, 52, and 53 for causing the laser beam irradiation position to track jump. The first jump signal generating circuit 51 is synchronized with the input timing of the index signal INDEX from the encoder 11a from the start of the first jump command from the computer device 70 to the end of the first jump command. And the laser beam irradiation position is jumped by one track inward in the radial direction of the optical disk DK. The first jump signal JUMP1 is supplied to the drive circuit 48 via the adder 47, and is composed of a positive pulse and a negative pulse immediately thereafter as shown in FIG. The positive pulse has a function of driving the objective lens 25 to move the irradiation position of the laser beam to the inside of the optical disk DK by one track, and the negative pulse is for applying a brake to the movement of the objective lens 25. is there.
[0036]
The second and third jump signal generation circuits 52 and 53 are operated in response to a command from the computer device 70 in synchronism with a pulse signal input from the timing determination circuit 54 for the first time after the command. JUMP3 is generated to jump the laser beam irradiation position by one track in the radial direction of the optical disk DK. The second and third jump signals JUMP2 and JUMP3 are also supplied to the drive circuit 48 via the adder 47, respectively. As shown in FIG. 11, the second jump signal JUMP2 is composed of a negative pulse and a positive pulse immediately thereafter, and jumps the irradiation position of the laser beam by one track outward in the radial direction of the optical disc DK. The third jump signal JUMP3 is composed of a positive pulse and a negative pulse immediately thereafter, and jumps the irradiation position of the laser beam by one track inward in the radial direction of the optical disc DK. Also in these cases, the previously generated pulse has a function of driving the objective lens 25 to move the irradiation position of the laser beam by one track of the optical disk DK, and the pulse generated immediately thereafter is the objective lens. It is for giving a brake to 25 movement.
[0037]
The timing determination circuit 54 is reset by the index signal INDEX from the encoder 11a and the rotation signal φ from the encoder 11a._A(Or rotation signal φ_B). When the count value reaches a predetermined value, the pulse signal is output to the second and third jump signal generation circuits 52 and 53 and the pulse signal is also supplied to the computer device 70 (see FIG. 11).
[0038]
A reproduction signal observation device 60 is also connected to the HF signal amplifier circuit 41. As shown in FIG. 3, the reproduction signal observation device 60 includes a reproduction signal generation circuit 61, a waveform equalization circuit 62, and a binarization circuit 63. The reproduction signal generation circuit 61 adds all the detection signals (light reception signals) A, B, C, and D from the photodetector elements 28a, 28b, 28c, and 28d, and generates the addition result A + B + C + D as a reproduction signal (so-called sum signal). SUM). The waveform equalization circuit 62 shapes the waveform so as to eliminate the difference in amplitude due to the signal length in the reproduction signal (for example, 3T to 11T for CD, 3T to 11T, 14T for DVD). The T will be described in detail later. The binarization circuit 63 converts the reproduction signal from the waveform equalization circuit 62 into digital data.
[0039]
The output of the waveform equalization circuit 62 is supplied to the waveform characteristic evaluation device 64, and the output of the binarization circuit 63 is supplied to the jitter measurement device 65, the error rate calculation circuit 66, and the computer device 70. The waveform characteristic evaluation device 64 measures the waveform shape (for example, the symmetry of the waveform) of the reproduction signal waveform-shaped by the waveform equalization circuit 62, and determines the quality of the reproduction signal. The jitter measuring device 65 is also called a time interval analyzer (TIA). The jitter measuring device 65 inputs a reproduction signal binarized by the binarizing circuit 63 as shown in FIG. The low level time is measured, a histogram (measurement time distribution of the high level and low level of the reproduction signal) as shown in FIG. 12B is created, and the jitter of the optical disc DK is measured.
[0040]
In the optical disc DK, usually, a plurality of types of bits are formed and desired data is recorded, but the type of bits (the length in the circumferential direction) is predetermined. When the optical disk is rotated at a constant linear velocity, as shown in FIG. 12 (A), the binarized reproduction signal is composed of a combination of pulse train signals having a plurality of types of time widths. For example, in the case of a CD, nine types of signals from 3T to 11T are used as the pulse width. In the case of DVD, 10 types of signals from 3T to 11T and 14T are used. Therefore, the jitter value (variation of each pulse width) of the optical disc DK can be measured by measuring each pulse width of the reproduction signal from the binarization circuit 63 and examining the variation.
[0041]
The error rate calculation circuit 66 compares the recorded digital data with the reproduced digital data, and calculates the error rate of the reproduced digital data. The measurement results of the waveform characteristic evaluation device 64, the jitter measurement device 65, and the error rate calculation circuit 66 are supplied to the computer device.
[0042]
The computer device 70 inspects the optical pickup 20 by executing the programs of FIGS. The computer device 70 is connected to an input device 71 composed of a keyboard, a mouse, etc., and a display device 72 composed of a CRT or a liquid crystal display.
[0043]
The operation of the embodiment configured as described above will be described. First, the operation of various circuits of the inspection apparatus including the computer device 70 is started by turning on a power switch (not shown). Then, the operator operates the input device 71 to select the inspection mode of the optical pickup 20 and set parameters necessary for each inspection mode. In the present embodiment, first to third modes are prepared as inspection modes. After selecting the inspection mode and setting the parameters, the optical pickup 20 to be inspected is assembled to the inspection apparatus. If a recordable optical disk DK such as a CD or DVD used for inspection is set on the support table 13, it may be left as it is. However, if a new optical disk DK is used, the new optical disk DK is attached to the support table 13. Set.
[0044]
Then, by operating the input device 71, the inspection device instructs to start inspection of the optical pickup 20. In response to this instruction, the computer device 70, according to the selected inspection mode, the first mode program (FIGS. 4 and 5), the second mode program (FIGS. 6 and 7), and the third mode program (FIGS. 8 to 8). The program of any one of 10) is executed.
[0045]
a. 1st mode
First, a case where the first mode is selected as the inspection mode will be described. The first mode is a mode for recording and reproducing inspection data for a plurality of tracks by repeatedly recording and reproducing inspection data for each track. In setting the parameters in the first mode, it is selected whether the recording direction of the inspection data on the optical disc DK is the outer side or the inner side. In addition, the number m of inspection data recorded in one track, the number n of recording tracks of the inspection data (same as the number of reproduction tracks n), and the inspection data are set. “M” is an integer greater than or equal to “1”, and “n” is an integer greater than or equal to 2.
[0046]
In response to the inspection start instruction of the optical pickup 20, the computer device 70 starts executing the first mode program in FIG. 4, controls the sled servo circuit 17 in step 102, and operates the feed motor 14. The irradiation position of the laser beam is moved slightly before the recording start position of the inspection data on the optical disc DK. In this case, if it is selected by the parameter setting that the laser light irradiation position is moved outward by one track, the laser light irradiation position is moved outward from the innermost track. On the contrary, if it is selected to move the irradiation position of the laser beam one track at a time, the irradiation position by the laser beam is moved inward from the outermost track. The recording start position is calculated and stored in the computer device 70 using the index signal INDEX from the encoder 14a in the feed motor 14 by the processing in step 158 at the end of the inspection of one optical pickup 20. Given by end position. Further, when an address signal is included in the reproduction signal, this address signal may be used as the recording start position instead of the previous end position calculated using the index signal INDEX.
[0047]
Next, at step 104, a spindle motor 11 rotation start command is output to the spindle motor control circuit 12 to start the spindle motor 11. In step 106, a reproduction laser power setting command is output to the laser power setting circuit 32. As a result, the laser power setting circuit 32 controls the emission of the reproduction laser beam by the laser light source 21 via the laser drive circuit 31, and the optical disk DK is irradiated with the reproduction laser beam.
[0048]
The optical disk DK reflects the laser light by the reproduction laser light irradiation, and the reflected light is received by the four-divided photodetector 28. The received light signals A, B, C, and D representing the received reflected light are supplied to the focus error signal generation circuit 42, the tracking error signal generation circuit 43, and the reproduction signal observation device 60 via the HF signal amplification circuit 41. The The focus error signal generation circuit 42 generates a focus error signal based on the received light signals A, B, C, and D, and performs focus servo control of the objective lens 25 in cooperation with the focus servo circuit 44, the drive circuit 45, and the focus actuator 29a. Begin to.
[0049]
The tracking error signal generation circuit 43 generates a tracking error signal based on the received light signals A, B, C, and D, and performs tracking servo control of the objective lens 25 in cooperation with the tracking servo circuit 46, the drive circuit 48, and the tracking actuator 29b. To do. The output of the tracking servo circuit 46 is also supplied to the sled servo circuit 17, and the sled servo circuit 17 starts sled servo control of the optical disk DK in cooperation with the feed motor 14. Further, the tracking error signal from the tracking error signal generation circuit 43 is supplied to the band pass filter 49. The band pass filter 49 extracts a wobble signal from the tracking error signal and supplies it to the spindle motor control circuit 12. The spindle motor control circuit 12 controls the rotation of the spindle motor 11 using this wobble signal, and controls the linear velocity in the circumferential direction of the optical disc DK with respect to the laser light to be constant. By this rotation of the optical disk DK, the irradiation position of the laser light rotates in a spiral manner toward the outside of the optical disk DK, as indicated by an arrow in FIG.
[0050]
The reproduction signal observation device 60 generates a reproduction signal based on the received light signals A, B, C, and D in the reproduction signal generation circuit 61. This reproduction signal is supplied to the computer device 70 via the waveform equalization circuit 62 and the binarization circuit 63.
[0051]
After the processing of step 106, the computer device 70 outputs a first jump start command signal to the first jump signal generation circuit 51 in step 108. The first jump signal generation circuit 51 stores the first jump start command signal and thereafter supplies the first jump signal JUPM1 to the drive circuit 48 via the adder 47 in synchronization with the index signal INDEX from the encoder 11a. (See FIG. 11). Thereby, as shown in FIG. 13, each time the laser beam irradiation position reaches a predetermined circumferential position X of the optical disc DK, the laser beam irradiation position jumps from the radially outer side to the inner side by one track. By the generation of the first jump signal JUMP1, the irradiation position of the laser beam is maintained on the same track unless second or third jump signals JUMP2 and JUMP3 described later are generated.
[0052]
After the processing in step 108, the computer device 70 determines in step 110 whether or not there is a reproduction signal from the binarization circuit 63 of the reproduction signal observation device 60, whereby data is stored in the laser light irradiation track on the optical disc DK. It is determined whether or not it is recorded. If data is recorded on the laser light irradiation track, “Yes” is determined in step 110, and the second or third jump signal generating circuits 52, 53 are in the second or third jump signal generating circuit 52 or 53 in step 112. A jump command is output. In this case, the second jump command is supplied to the second jump signal generation circuit 52 if the recording direction of the inspection data on the optical disc DK is selected to be the outer direction by the parameter setting. On the contrary, if the recording direction of the inspection data on the optical disc DK is selected to be inward, the third jump command is supplied to the third jump signal generation circuit 53.
[0053]
When the second jump command is supplied to the second jump signal generation circuit 52, the second jump signal generation circuit 52 waits for the pulse signal from the timing determination circuit 54 and outputs the second jump signal JUMP2 synchronized with the pulse signal. This is supplied to the drive circuit 48 via the adder 47. Therefore, in this case, as shown in FIG. 13, when the irradiation position of the laser beam reaches the predetermined circumferential position Y of the optical disc DK, the irradiation position of the laser beam jumps by one track from the inside in the radial direction to the outside. To do. The second jump signal generation circuit 52 does not generate the second jump signal JUMP2 even if a pulse signal is supplied from the timing determination circuit 54 unless the second jump command signal is supplied next.
[0054]
When the third jump command is supplied to the third jump signal generation circuit 53, the third jump signal generation circuit 53 waits for the pulse signal from the timing determination circuit 54 and outputs the third jump signal JUMP3 synchronized with the pulse signal. This is supplied to the drive circuit 48 via the adder 47. Therefore, in this case, when the irradiation position of the laser beam reaches the predetermined circumferential position Y of the optical disc DK, the irradiation position of the laser beam jumps by one track from the outside in the radial direction. The third jump signal generation circuit 52 does not generate the third jump signal JUMP3 even if the pulse signal is supplied from the timing determination circuit 54 unless the third jump command signal is supplied next.
[0055]
After the process of step 112, the computer apparatus 70 waits for the arrival of the pulse signal from the timing determination circuit 54 by the determination process of step 114, and returns to step 110. By such processing of steps 110 to 114, the irradiation position of the laser beam moves one track at a time until the track on which no data is recorded is detected.
[0056]
When the computer device 70 reaches a track on which no data is recorded, the computer device 70 proceeds to step 116 and subsequent steps by the determination process of step 110. Then, the computer device 70 waits for the index signal INDEX from the encoder 11 a by the determination processing in steps 116 and 118, outputs a recording laser power setting command to the laser power setting circuit 32, and outputs to the recording signal generation circuit 33. A recording signal supply command is output together with the inspection data. The laser power setting circuit 32 controls the laser driving circuit 31 so that the laser light source 21 emits laser light having a recording power larger than the above-described reproducing power. The recording signal generation circuit 33 outputs a recording signal composed of an on / off signal according to the inspection data to the laser driving circuit 31 so that the laser light source 21 emits a laser beam having a pattern corresponding to the recording signal. The laser drive circuit 31 is controlled. On the other hand, when the index signal INDEX arrives at step 116, the first jump circuit 51 also receives the index signal INDEX from the encoder 11a, and moves the irradiation position of the laser beam inward by one track. Therefore, the inspection data is recorded on a track in which no data is detected, which is detected by the processing of step 110.
[0057]
After the processing of steps 116 and 118, the computer 70 waits for the index signal INDEX from the encoder 11a by the processing of steps 120 and 122, and outputs a reproduction laser power setting command to the laser power setting circuit 32. A recording signal supply stop command is output to the recording signal generation circuit 33. The laser power setting circuit 32 controls the laser driving circuit 31 so that the laser light source 21 emits laser light having a reproducing power. The recording signal generation circuit 33 stops outputting the recording signal from the laser driving circuit 31. Thereby, the inspection data is recorded on only one track, and the optical pickup 20 is switched for reproduction.
[0058]
On the other hand, when the index signal INDEX arrives at step 120, the first jump circuit 51 also receives the index signal INDEX from the encoder 11a, and moves the laser beam irradiation position inward by one track. Therefore, the irradiation position of the laser beam is maintained on the track on which the inspection data is recorded, and the recorded inspection data starts to be reproduced.
[0059]
After the processing of step 122, the computer device 70 uses the timer built in the computer device 70 by the processing of steps 124 to 128 to use the gate time sandwiched between the gate start timing GT1 and the gate end timing GT2. During the process (see FIG. 11), the reproduction signal acquisition command is continuously output to the waveform characteristic evaluation device 64, the jitter measurement device 65, and the error rate calculation circuit 66 in the reproduction signal observation device 60. In response to the capture command, during the gate time, the waveform characteristic evaluation device 64 continues to capture and store the reproduction signal supplied from the waveform equalization circuit 62, and the jitter measurement device 65 and the error rate calculation circuit 66 binarize. The reproduction signal supplied from the circuit 63 is taken in and stored.
[0060]
The reason for providing the gate time in this way is that the reproduction signal greatly fluctuates regardless of the inspection data recorded on the optical disk DK during and immediately after the irradiation track of the laser beam is changed. This is to prevent the fluctuation from affecting the inspection of the optical pickup 20. The gate start timing GT1 and the gate end timing GT2 used for the processing of steps 124 and 126 are determined to be different values according to the radial irradiation position of the laser beam using the interval of the index signal INDEX that is input as needed. . This is because the rotational speed of the optical disk changes according to the irradiation position in the radial direction of the laser light because the rotational speed of the optical disk DK is controlled at a constant linear speed. Note that the gate time between the gate start timing GT1 and the gate end timing GT2 can be arbitrarily set by the operator as long as it is shorter than the time between the adjacent index signals INDEX.
[0061]
Further, the measurement of the gate start timing GT1 and the gate end timing GT2 is not performed by a timer, but the rotation signal φ from the encoder 11a._A(Or rotation signal φ_B) May be used for measurement. In this case, as indicated by a broken line in FIG. 1, the rotation signal φ from the encoder 11a_A(Or rotation signal φ_B) To the computer device 70. And the rotation signal φ from the arrival of the index signal INDEX_A(Or rotation signal φ_B) Is counted, and when the counted number of pulses has reached each predetermined value, “YES” is determined in steps 124 and 126, respectively. In this case, the rotation signal φ_A(Or rotation signal φ_BThe number of pulses per revolution of the optical disk DK in (1) is always constant regardless of the rotational speed of the optical disk DK. Therefore, even if the rotational speed of the optical disk DK changes, each predetermined value to be compared with the number of pulses is changed. It does not have to be.
[0062]
When the gate time elapses, the computer device 70 determines “Yes” in step 126 and proceeds to step 130 in FIG. 5. In step 130, the computer device 70 outputs a reproduction signal measurement processing command to the waveform characteristic evaluation device 64, the jitter measurement device 65, and the error rate calculation circuit 66 in the reproduction signal observation device 60. Thereafter, the computer device 132 waits for the end of the reproduction signal measurement processing by the waveform characteristic evaluation device 64, the jitter measurement device 65 and the error rate calculation circuit 66 in step 132.
[0063]
On the other hand, the waveform characteristic evaluation device 64, the jitter measurement device 65, and the error rate calculation circuit 66 measure the waveform shape, jitter value, and error rate of the captured and stored reproduction signal, respectively. When the measurement is finished, the waveform characteristic evaluation device 64, the jitter measurement device 65, and the error rate calculation circuit 66 clear the captured and stored reproduction signal and supply the measurement result and the measurement end signal to the computer device 70. . The computer device 70 determines “Yes” based on the measurement end signal in step 132, and stores data representing the measurement result in a memory in step 134.
[0064]
After storing the measurement result in step 134, the count value CNT1 is incremented by "1" in step 136. The count value CNT1 is used to measure the number of times the recording inspection data of the same track is measured, and is initially set to “0”. In step 138, it is determined whether the count value CNT1 is equal to the set parameter value m, so that the reproduction signal measurement for one track is repeated m times, that is, the processing in steps 124 to 134 is repeated m times. Determine. If the measurement of the reproduction signal for one track has not reached m times, “No” is determined in step 138, and the process of step 140 waits for the arrival of the index signal INDEX signal from the encoder 11 a. The reproduction signal for one track consisting of .about.134 is captured and measured again. In this case, the first jump signal generating circuit 51 also moves the irradiation position of the laser beam by one track in response to the arrival of the index signal INDEX from the encoder 11a during the processing of step 140. The same inspection data as the data is reproduced and measured.
[0065]
When the reproduction signal measurement for one track reaches m times, “Yes” is determined in step 138, the count value CNT 1 is cleared to “0” in step 142, and the process proceeds from step 144 onward. As a result, the computer apparatus 70 stores m reproduction measurement results of inspection data recorded on the same track. FIG. 11 shows the reproduction signal capture and measurement processing when the parameter value m is set to “2”. In FIG. 13, the recording and reproducing state of the first inspection data is indicated by a solid line, and the recording and reproducing state of the second inspection data is indicated by a broken line.
[0066]
After the processing of step 142, the count value CNT2 is incremented by “1” in step 144. The count value CNT2 is used to measure the number of tracks on which inspection data has been recorded and reproduced, and is initially set to “0”. In step 146, it is determined whether the count value CNT2 is equal to the set parameter value n, so that the number of tracks in which the test data is recorded and reproduced is n tracks, that is, the processing in steps 110 to 150 is performed n. Determine if it has been repeated. If the number of tracks on which the inspection data has been recorded and reproduced has not reached n tracks, it is determined as “No” in step 146, and the processing in steps 148 and 150 similar to the processing in steps 112 and 114 in FIG. To move the laser light irradiation position outward or inward by one track.
[0067]
Then, when the number of tracks in which the test data is recorded and reproduced reaches n tracks by the repetition processing of steps 110 to 150 described above, “Yes” is determined in step 146, and the count value CNT 2 is determined in step 152. It is cleared to “0”, and the processing after step 154 is executed. In step 154, a first jump stop command is output to the first jump signal generation circuit 51. Accordingly, the first jump signal generation circuit 51 does not generate the first jump signal JUMP1 even when the index signal INDEX is input from the encoder 11a. Next, in step 156, a laser power off command is output to the laser power setting circuit 32. As a result, the laser power setting circuit 32 controls the laser light source 21 via the laser driving circuit 31 and stops the emission of the laser light from the laser light source 21.
[0068]
After the processing in step 156, in step 158, the computer device 70 captures and stores the recording end position of the inspection data on the optical disc DK. The recording end position is calculated by inputting the index signal INDEX from the encoder 14a and counting the index signal INDEX by program processing (not shown). Alternatively, if the address of the optical disc DK can be detected from the reproduction signal, the detected address can be used as the recording end position of the inspection data.
[0069]
After the processing in step 158, in step 160, a spindle motor 11 rotation end command is output to the spindle motor control circuit 12 to stop the operation of the spindle motor 11. Next, in step 162, the measurement results by the reproduction signal observation device 60 m times per track stored in the process of step 134 are processed and evaluated, and the final evaluation result is obtained. It is displayed on the display device 72. In step 164, the execution of the first mode program is terminated.
[0070]
After the execution of the first mode program, the operator determines the quality of the optical pickup 20 based on the evaluation result by the display device 72. Note that it is possible to perform a program process until the quality of the optical pickup 20 is judged, and to display the quality on the display device 72. Then, new optical pickups 20 are assembled in the inspection apparatus one after another, and the quality of new optical pickups 20 is inspected one after another by executing the first mode program described above.
[0071]
As can be understood from the above description, according to the execution of the first mode program, the irradiation position of the laser beam is changed to the recording start position of the inspection data on the optical disc DK (the previous time) by the processing of steps 102 to 114 in FIG. The initial position is moved to a position slightly before the end position of the inspection data), and then the laser beam irradiation position is moved one track at a time in the initial movement direction, and on the optical disk DK based on the reproduction signal from the optical pickup 20. Confirm the existence of recorded data in. Then, when the confirmation does not confirm the presence of the recording data on the optical disc DK, the processing after step 116 is executed to start recording the inspection data on the optical disc DK by the optical pickup 20. Therefore, according to this, since the inspection data is surely recorded from the track next to the track on which data is already recorded on the optical disc DK, it is possible to prevent the recordable area of the optical disc DK from being consumed. . As a result, the optical disk is effectively used for the inspection of the optical pickup.
[0072]
Further, according to the execution of the first mode program, the processing of steps 110 to 150 causes the laser beam irradiation position by the optical pickup 20 to jump by one track, and the inspection data is recorded on the optical disc for one track, and thereafter In addition, the process of returning the irradiation position of the laser beam to the track on which the inspection data is recorded and reproducing the inspection data for evaluation of the reproduction signal is repeatedly executed. According to this, since the inspection data for a plurality of tracks are reproduced for each track, it is possible to distinguish between defects such as scratches on the optical disk to be used and optical pickup defects. As a result, the optical pickup 20 is accurately inspected.
[0073]
In the first mode program, the measurement process is repeated each time the inspection data for one track is reproduced by the processes of steps 124 to 140, and the inspection data recorded once is reproduced a plurality of times. The measurement results were derived. However, instead of this, the inspection data for one track is continuously reproduced a plurality of times and the data reproduced a plurality of times is stored respectively, and finally the inspection data recorded once is recorded a plurality of times. A measurement result based on reproduction may be derived.
[0074]
b. Second mode
Next, a case where the second mode is selected as the inspection mode will be described. The second mode is a mode in which inspection data is continuously recorded on a plurality of tracks, and thereafter the inspection data is reproduced one track at a time. Also in the setting of the parameter in the second mode, it is selected whether the recording direction of the inspection data on the optical disc DK is the outside direction or the inside direction. Also, the number m of inspection data recorded on one track is set, and the number n of tracks on which inspection data is continuously recorded and the inspection data are set. “M” is an integer greater than or equal to “1”, and “n” is an integer greater than or equal to 2.
[0075]
In this second mode, the computer device 70 starts execution of the second mode program in FIG. 6, and the execution of steps 202 to 214 similar to the above-described steps 102 to 114 sets the irradiation position of the laser beam to the optical disk. After moving to a position slightly before the recording start position of the previous inspection data in DK, the presence / absence of a reproduction signal is determined for each track, and the irradiation position of the laser beam is moved to an unrecorded track of data.
[0076]
When reaching the track on which no data is recorded, the computer device 70 clears the count value CNT2 for counting the number of recording tracks of inspection data to “0” in step 216. Next, the inspection data is recorded on one track by the processes of steps 218, 220, 224, and 226 similar to the processes of steps 116 to 122 described above. At the time of this recording, the count value CNT2 is incremented by “1” by the process of step 222.
[0077]
Next, in step 228, it is determined whether the recording of the inspection data on n tracks is completed by determining whether the count value CNT2 is equal to the set parameter value n. If the recording of the inspection data to n tracks has not been completed, “No” is determined in step 228, and the initial parameter setting is performed by the processing in step 230 similar to the processing in step 212. The irradiation position of the laser beam is jumped in the direction, and the process returns to step 218. Then, when the recording of the inspection data onto the n tracks is completed by the processing of these steps 218 to 230, “Yes” is determined in step 228 and the process proceeds to step 232. The recording state of the n track inspection data is shown in FIG. In FIG. 14, a solid line indicates a track on which inspection data is recorded, and a broken line indicates an unrecorded track of data.
[0078]
In step 232, the count value CNT2 is cleared to “0”. Then, the irradiation position of the laser beam is returned to the track at the recording start position of the inspection data by the processing of steps 234 and 236 similar to the processing of steps 212 and 214. Therefore, the process of step 234 in this case is to jump the irradiation position of the laser beam in the opposite direction to the process of step 212. That is, if it is selected that the recording direction of the inspection data on the optical disk DK is set to the outside direction in the initial parameter setting, the third jump signal is output to jump the laser beam irradiation position to the inside by one track. . On the other hand, if it is selected that the recording direction of the inspection data on the optical disk DK is set to the inner side in the initial parameter setting, the second jump signal is output to jump the laser beam irradiation position outward by one track. Let
[0079]
After these steps 234 and 236, the count value CNT2 is incremented by “1” in step 238, and the count value CNT2 is decreased to “n−1” by “1” smaller than the set parameter value n in step 240. Determine if they are equal. That is, it is determined whether the irradiation position of the laser beam has been returned to the track at the recording start position of the inspection data. While the irradiation position of the laser beam is not returned to the track at the recording start position of the inspection data, the circulation process consisting of steps 234 to 240 is repeatedly executed based on the determination of “No” in step 240, The irradiation position is moved one track at a time in the direction opposite to the recording direction of the inspection data. When the irradiation position of the laser beam is returned to the track at the recording start position of the inspection data, “Yes” is determined in Step 240, and the count value CNT 2 is cleared to “0” in Step 242. The process proceeds to step 244 and subsequent steps.
[0080]
In step 244, the process waits for the index signal INDEX from the encoder 11a, and proceeds to the processing after step 246. The processing of steps 246 to 260 is the same as the processing of steps 124 to 138 described above, whereby the recorded inspection data for one track is reproduced and measured one track at a time, and the number of times of reproduction and measurement is determined. To do. The cyclic processing of steps 244 to 260 is repeated until the reproduction and measurement of the inspection data for one track reaches the set parameter value m. When the reproduction and measurement of the inspection data for one track reaches the set parameter value m, “Yes” is determined in step 260 and the processing of steps 262 to 266 is executed.
[0081]
The processing of steps 262 to 266 is the same as the processing of 142 to 146 described above, and thereby, it is determined whether the reproduction and measurement of inspection data for n tracks have been completed. If the reproduction and measurement of the inspection data for n tracks are not completed, it is determined as “No” in step 266, and the processing of steps 268 and 270 similar to the above-described steps 148 and 150 is executed. The laser beam irradiation position is jumped by one track in the direction initially set by parameter setting. Then, returning to step 244, the circulation processing of steps 244 to 270 is repeated until the reproduction and measurement of the inspection data for n tracks is completed. When the reproduction and measurement of the inspection data for n tracks are completed by this cyclic processing, “Yes” is determined in step 266, and end processing including steps 272 to 280 similar to the processing in steps 152 to 162 described above is performed. In step 284, the execution of the second mode program is terminated.
[0082]
Even after the execution of the second mode program, the operator determines the quality of the optical pickup 20 based on the evaluation result by the display device 72. Also in this case, as in the case of the first mode, the determination of whether the optical pickup 20 is good or bad may be performed by program processing. Then, new optical pickups 20 are sequentially assembled in the inspection apparatus, and the new optical pickups 20 are inspected one after another by executing the second mode program described above.
[0083]
As can be understood from the above description, even when the second mode program is executed, the inspection data is already stored in the optical disc DK as in the case of the first mode by the processing of steps 202 to 214 in FIG. Is reliably recorded from the track next to the track on which is recorded, so that the recordable area of the optical disc DK is prevented from being consumed. As a result, the optical disk is effectively used for the inspection of the optical pickup.
[0084]
Further, according to the execution of the second mode program, the inspection data is continuously recorded on n tracks (a plurality of tracks) by the process of steps 216 to 230, and then the laser is performed by the process of steps 232 to 240. The light irradiation position was returned to the track at the recording start position of the inspection data. Then, the inspection data recorded on the plurality of tracks was reproduced one track at a time by the processing of steps 242 to 270, and the reproduced signal was measured. According to this, since the inspection data for a plurality of tracks are reproduced for each track, it is possible to distinguish between defects such as scratches on the optical disk to be used and optical pickup defects. As a result, the optical pickup 20 is accurately inspected.
[0085]
In the second mode program, the measurement process is repeated each time the inspection data for one track is reproduced by the processes in steps 242-270. However, instead of this, the inspection data for one track is continuously reproduced a plurality of times and the data reproduced a plurality of times is stored respectively, and finally the inspection data recorded only once is recorded. A measurement result based on a plurality of reproductions may be derived.
[0086]
c. 3rd mode
Next, a case where the third mode is selected as the inspection mode will be described. The third mode is a mode for reproducing and measuring inspection data separately for a case where data is not recorded on an adjacent track and a case where data is recorded on an adjacent track. Also in the setting of the parameter in the third mode, it is selected whether the recording direction of the inspection data on the optical disc DK is the outside direction or the inside direction. In addition, the number of times m of inspection data recorded in one track is set. “M” is an integer greater than or equal to “1”.
[0087]
In this third mode, the computer device 70 starts execution of the third mode program in FIG. 8, and the execution of steps 302 to 314 similar to the above-described steps 102 to 114 sets the irradiation position of the laser beam to the optical disk. After moving to a position slightly before the recording start position of the previous inspection data in DK, the presence / absence of a reproduction signal is determined for each track, and the irradiation position of the laser beam is moved to an unrecorded track of data.
[0088]
When reaching the track on which no data is recorded, the computer device 70 makes a “Yes” determination at step 310, and the processing at steps 316, 318 and steps 322, 324 similar to the processing at steps 312, 314, respectively. Then, the laser beam irradiation position is jumped by one track each in the setting direction based on the initial parameters (the same as the direction in the process of step 312), for a total of two tracks. Even during these jump processes, the presence or absence of a reproduction signal, that is, the unrecorded data of the jumped track is determined by the processes of steps 320 and 326 similar to step 310. If it is determined that the data in step 320 or 326 is “No”, that is, the data is not recorded, the process returns to step 312 and the processes in steps 310 to 314 are repeated.
[0089]
These processes in steps 310 to 326 are for searching for three consecutive tracks in which no data is recorded. When the corresponding three tracks are found, the process waits for the index signal INDEX from the encoder 11a at step 328 and outputs the third or second jump command at step 330. The process of step 330 is a process of returning the irradiation position of the laser beam jumped by three tracks by the processes of steps 312, 316 and 322 to the center track. Therefore, when the irradiation position of the laser beam jumps to the outside by the processing in steps 312, 316, 322 according to the initially set parameters, the third jump command is output to the third jump signal generation circuit 53. Thus, the irradiation position of the laser beam jumps inward. On the other hand, when the laser beam irradiation position jumps inward by the processing of steps 312, 316, and 322, the second jump command is output to the second jump signal generation circuit 53, and the laser beam irradiation position is Jump outward.
[0090]
After this step 330 processing, the inspection data is recorded on one track at the center by the processing of steps 332 to 338 similar to steps 116 to 122 described above. Next, the recorded inspection data for one track is reproduced m times by the cyclic processing in steps 340 to 356 similar to steps 124 to 140 described above, and the reproduced signal is measured.
[0091]
When the reproduction and measurement of the test data recorded in the central track is completed m times and the count value CNT1 reaches the parameter value m by the cyclic processing including the steps 340 to 356, “Yes” is determined in step 354. And the process proceeds to step 358. In step 358, the count value CNT1 is cleared to “0”. In step 360, after data is recorded on the tracks on both sides of the central track, the inspection data recorded on the central track is reproduced again, and the count value CNT3 used for measuring the reproduced signal is “ 1 ”is determined. The count value CNT3 is initially set to “0”. Therefore, in this case, it is determined as “No” in step 360, the count value CNT3 is incremented by “1” in step 362 in FIG. 10, and the processing in steps 364 to 392 is executed.
[0092]
The processing of steps 364 to 374 is the same type of processing as the processing of steps 328 to 338. With this, the irradiation position of the laser light is jumped inward by one track from the central track, and the inspection data is recorded. However, in this case, the processing of step 366 may simply move the irradiation position of the laser beam to the inner side regardless of the parameters set in the initial stage, so that the third jump command is sent to the third jump signal generation circuit 53. Output.
[0093]
The processing of steps 376 to 388 is also the same type of processing as the processing of steps 328 to 338. By this, the irradiation position of the laser beam is jumped outward by two tracks from the inner track of the central track, and the inspection data Record. However, in this case, since the processing of steps 376 and 380 may be performed by simply moving the irradiation position of the laser beam to the outside regardless of the parameters set in the initial stage, the second jump command is issued to the second jump signal generation circuit. 52 may be output. After the processing in steps 376 to 388, a third jump command is output to the third jump signal generating circuit 53 in step 390 to return the irradiation position of the laser beam to the central track, and in step 392, the index from the encoder 11a is returned. Waiting for the arrival of the signal INDEX, the process returns to step 340 in FIG.
[0094]
In place of the processing in these steps 364 to 392, the inspection data is recorded first on the outer track by one track from the central track, and thereafter the inspection data is recorded on the inner track by only one track of the central track. Finally, the laser beam irradiation position can be moved outward by one track and returned to the central track. In this case, the second jump command is output to the second jump signal generation circuit 52 at step 366, the third jump command is output to the third jump signal generation circuit 53 at steps 376 and 380, and the second jump command is output at step 390. The two jump command may be output to the second jump signal generation circuit 52. In addition, as described above, any data may be recorded on the tracks on both sides of the central track, and it is not particularly necessary to use inspection data.
[0095]
By returning to step 340, the computer device 70 performs reproduction and measurement of the inspection data recorded in the central track m times by executing the circulation process including steps 340 to 356 described above. After the m times of reproduction and measurement, “Yes” is determined in step 354, and after the count value CNT1 in step 358 is cleared, the determination processing in step 360 is executed. In this case, the count value CNT3 has been counted up to “1” by the processing of step 362, so that “Yes” is determined in step 360. Then, after clearing the count value CNT3 to “0” in step 394, the end process consisting of steps 396 to 404 similar to the process of steps 154 to 162 described above is executed, and in step 406 this third mode is executed. Terminates program execution.
[0096]
Even after the execution of the third mode program, the operator determines the quality of the optical pickup 20 based on the measurement result by the display device 72. Also in this case, as in the case of the first and second mode programs, the determination of the quality of the optical pickup 20 may be performed by program processing. Then, new optical pickups 20 are assembled in the inspection apparatus one after another, and the quality of new optical pickups 20 is inspected one after another by executing the above-described third mode program.
[0097]
As can be understood from the above description, according to the execution of the first mode program, the irradiation position of the laser beam is changed to the recording start position of the inspection data on the optical disc DK (the previous time) by the processing of steps 302 to 326 in FIG. Based on the reproduction signal of the recording data from the optical pickup 20 while moving the irradiation position of the laser beam one track at a time in the initial movement direction. The presence of recording data on the optical disc DK is confirmed. Then, when the presence of recording data on the optical disk DK is not confirmed continuously by the confirmation, data for inspection by the optical pickup 20 is recorded on the central track of the three tracks by the processing of steps 328 to 338. . Therefore, according to this, since the inspection data is surely recorded from the track next to the track on which data is already recorded on the optical disc DK, it is possible to prevent the recordable area of the optical disc DK from being consumed. . As a result, the optical disk is effectively used for the inspection of the optical pickup.
[0098]
Further, according to the execution of the third mode program, the processing of steps 328 to 356 records the inspection data only on the central track of the three unrecorded tracks, and reproduces the recorded inspection data. And evaluated. After that, after the inspection data was recorded on the tracks on both sides of the central track by the processing of steps 360 to 392, 340 to 356, the inspection data recorded on the central track was again reproduced and evaluated. As a result, the inspection data is reproduced and evaluated separately for the case where the data is recorded on the adjacent track and the case where the data is not recorded. Therefore, the optical pickup 20 considers the presence / absence of the data of the adjacent track. The optical pickup is accurately inspected.
[0099]
In the third mode, only the reproduction and evaluation of inspection data for one track is performed. However, the reproduction and evaluation of inspection data for a plurality of tracks are performed as in the first and second modes. You may make it perform. In this case, as in the case of the first and second modes, the number of tracks n (an integer of 2 or more) for reproducing and evaluating the inspection data is set, and the case of the first and second modes is set. The process of steps 310 to 392 may be repeated n times by a similar method.
[0100]
Also in this case, as in the first and second modes, the inspection data for one track is continuously reproduced a plurality of times and the data reproduced a plurality of times is stored, and finally You may make it derive | lead-out the measurement result based on multiple times reproduction | regeneration with respect to the said test | inspection data recorded only once.
[0101]
Furthermore, in carrying out the present invention, the present invention is not limited to the above embodiment and its modifications, and various modifications can be made without departing from the object of the present invention.
[0102]
For example, in the above embodiment, only one program among the first to third mode programs is applied to one optical pickup 20 to inspect the optical pickup 20. However, one optical pickup 20 may be inspected by applying two or more programs among the first to third mode programs to one optical pickup 20.
[0103]
In the above embodiment, if the track jump is not performed, the irradiation position of the laser light is sequentially moved from the inner side to the outer side of the optical disc DK as the optical disc DK is rotated. However, the present invention is also applied to the case where the irradiation position of the laser light sequentially moves from the outside to the inside of the optical disk DK as the optical disk DK rotates, when track jump is not performed. In this case, as the first jump signal generation circuit 51 for maintaining the laser beam irradiation position on the same track, the laser beam irradiation position is changed every time the optical disk DK rotates once as in the second jump signal generation circuit 52. A track jump circuit that changes only one track from the inside to the outside may be used.
[0104]
Further, in the above embodiment, in order to change the radial relative position between the optical pickup 20 and the optical disc DK, the spindle motor 11 and the support using the feed mechanism including the feed motor 14, the screw rod 15, the support member 16, and the like. The table 13 was moved. However, instead of this, the relative position in the radial direction between the optical pickup 20 and the optical disk DK may be changed by moving the entire optical pickup 20 in the radial direction of the optical disk DK by a feed mechanism.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing an entire optical pickup inspection apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic view of the quadrant photodetector in FIG. 1;
FIG. 3 is a detailed block diagram of the reproduction signal observation apparatus of FIG. 1;
4 is a flowchart showing the first half of a first mode program executed by the computer apparatus of FIG. 1; FIG.
FIG. 5 is a flowchart showing the second half of the first mode program executed by the computer apparatus of FIG. 1;
6 is a flowchart showing the first half of a second mode program executed by the computer apparatus of FIG. 1; FIG.
FIG. 7 is a flowchart showing the second half of the second mode program executed by the computer apparatus of FIG. 1;
FIG. 8 is a flowchart showing a first half of a third mode program executed by the computer apparatus of FIG. 1;
FIG. 9 is a flowchart showing the second half of the third mode program executed by the computer apparatus of FIG. 1;
FIG. 10 is a flowchart showing an intermediate part of a third mode program executed by the computer apparatus of FIG. 1;
FIG. 11 is a time chart of signal waveforms at various parts in FIG. 1;
FIG. 12 is an explanatory diagram illustrating an example for explaining an example of jitter measurement;
FIG. 13 is an explanatory diagram for describing a track jump operation in a first mode.
FIG. 14 is an explanatory diagram for describing a track jump operation in a second mode.
[Explanation of symbols]
DK ... optical disc, 11 ... spindle motor, 14 ... feed motor, 20 ... optical pickup, 21 ... laser light source, 27 ... quadrant photodetector, 31 ... laser drive circuit, 42 ... focus error signal generation circuit, 44 ... tracking error signal generation Circuit 51, first jump signal generating circuit 52, second jump signal generating circuit, 53, third jump signal generating circuit, 60, reproduction signal observation device, 70, computer device.

Claims (14)

An optical pickup that rotates an optical disc, records inspection data on the optical disc by an optical pickup, reproduces the inspection data recorded on the optical disc by an optical pickup, evaluates a reproduction signal by the reproduction, and inspects the optical pickup. In inspection equipment,
Initial moving means for initially moving the irradiation position of the laser beam by the optical pickup to a position slightly before the recording start position of the inspection data on the optical disc;
Recording data confirmation means for confirming the presence of recording data on the optical disk based on a reproduction signal of the recording data by the optical pickup after the movement of the laser light irradiation position by the initial movement means;
An optical pickup comprising recording start control means for starting recording of inspection data on the optical disk by the optical pickup when the recording data confirmation means no longer confirms the presence of recording data on the optical disk. Inspection equipment. In the inspection device for an optical pickup according to claim 1,
The recorded data confirmation means includes
First jump control means for jumping by one track each time the optical disk makes one rotation to return the irradiation position of the laser beam by the optical pickup to the position before one rotation;
Determination means for confirming the presence of recording data based on the presence or absence of a reproduction signal of recording data on the track after the jump by the first jump control means;
Second jump control means for causing the laser beam irradiation position by the optical pickup to jump one track in the same direction as the movement direction of the laser light irradiation position by the initial movement means when the determination means confirms the presence of the recording data; Optical pickup inspection device including An optical pickup that rotates an optical disc, records inspection data on the optical disc by an optical pickup, reproduces the inspection data recorded on the optical disc by an optical pickup, evaluates a reproduction signal by the reproduction, and inspects the optical pickup. In inspection equipment,
Recording jump control means for jumping the irradiation position of the laser beam to the optical disk by the optical pickup by one track;
After jump control by the recording jump control means, recording control means for controlling the optical pickup to record inspection data on the track after the jump;
After recording the inspection data by the recording control means, reproduction jump control means for jumping the irradiation position of the laser beam by the optical pickup to the track on which the inspection data is recorded,
After the jump control of the laser beam irradiation position by the reproduction jump control means, the reproduction control means for controlling the optical pickup to reproduce the inspection data recorded on the track after the jump for the evaluation of the reproduction signal. When,
The recording jump control means, recording control means, Rutotomoni a repeat control means for repeatedly perform the control operation by the reproducing jump control means and the reproduction control means further
Initial moving means for initially moving the irradiation position of the laser beam by the optical pickup to a position slightly before the recording start position of the inspection data on the optical disc;
Recording data confirmation means for confirming the presence of recording data on the optical disk based on a reproduction signal of the recording data by the optical pickup after moving the irradiation position of the laser beam by the initial movement means,
An optical recording apparatus in which initial recording of inspection data on an optical disc by an optical pickup by the recording control unit is started when the recording data confirmation unit no longer confirms the presence of recording data on the optical disc. Pickup inspection device. An optical pickup that rotates an optical disc, records inspection data on the optical disc by an optical pickup, reproduces the inspection data recorded on the optical disc by an optical pickup, evaluates a reproduction signal by the reproduction, and inspects the optical pickup. In inspection equipment,
Recording control means for controlling the optical pickup to continuously record inspection data on a plurality of tracks of the optical disc;
Rutotomoni a reproduction control means for reproducing the after recording of the test data by the recording control means, the test data of a plurality of tracks which is the recording by controlling the optical pickup by one track for evaluation of the reproduction signal ,further
Initial moving means for initially moving the irradiation position of the laser beam by the optical pickup to a position slightly before the recording start position of the inspection data on the optical disc;
Recording data confirmation means for confirming the presence of recording data on the optical disk based on a reproduction signal of the recording data by the optical pickup after moving the irradiation position of the laser beam by the initial movement means,
An optical recording apparatus in which initial recording of inspection data on an optical disc by an optical pickup by the recording control unit is started when the recording data confirmation unit no longer confirms the presence of recording data on the optical disc. Pickup inspection device. In the inspection apparatus for an optical pickup according to claim 4,
The reproduction control means includes
After recording the inspection data by the recording control means, the reproduction start jump control means for jumping the irradiation position of the laser beam by the optical pickup to the track where recording of the inspection data is started,
After the jump control by the reproduction start jump control means, every time the inspection data is reproduced for one track from the optical disk, the irradiation position of the laser beam by the optical pickup is set to 1 in the direction opposite to the jump direction by the reproduction start jump control means. An optical pickup inspection apparatus including a jump control means for reproduction for jumping track by track. An optical pickup that rotates an optical disc, records inspection data on the optical disc by an optical pickup, reproduces the inspection data recorded on the optical disc by an optical pickup, evaluates a reproduction signal by the reproduction, and inspects the optical pickup. In inspection equipment,
First recording control means for controlling the optical pickup to record inspection data on the track of the optical disc;
First reproduction control means for controlling the optical pickup after the recording of the inspection data by the first recording control means and reproducing the inspection data recorded by the first recording control means for evaluation of the reproduction signal; ,
After the reproduction of the inspection data by the first reproduction control means, the second recording for controlling the optical pickup and recording the data on the track of the optical disk located on both sides of the track on which the inspection data is recorded by the first recording control means. Control means;
And second reproduction control means for controlling the optical pickup after the data recording by the second recording control means to reproduce the inspection data recorded by the first recording control means for evaluation of the reproduction signal. An optical pickup inspection device characterized by the above. The optical pickup inspection apparatus according to claim 6 , further comprising:
Initial moving means for initially moving the irradiation position of the laser beam by the optical pickup to a position slightly before the recording start position of the inspection data on the optical disc;
Recording data confirmation means for confirming that there is no recording data on at least three consecutive tracks on the optical disk based on a reproduction signal of the recording data by the optical pickup after the irradiation position of the laser beam is moved by the initial movement means; ,
An inspection apparatus for an optical pickup, wherein the first recording control means records inspection data on a central track of three tracks where the recording data does not exist. An optical pickup that rotates an optical disc, records inspection data on the optical disc by an optical pickup, reproduces the inspection data recorded on the optical disc by an optical pickup, evaluates a reproduction signal by the reproduction, and inspects the optical pickup. In the inspection method,
An initial moving step of initially moving the irradiation position of the laser beam by the optical pickup to a position slightly before the recording start position of the inspection data on the optical disc;
A recording data confirmation step for confirming the presence of the recording data on the optical disk based on a reproduction signal of the recording data by the optical pickup after the movement of the irradiation position of the laser beam by the initial movement step;
A recording start control step for starting recording of inspection data on the optical disc by the optical pickup when the recording data confirmation step no longer confirms the presence of the recording data on the optical disc. Inspection method. The optical pickup inspection method according to claim 8 ,
The recorded data confirmation step includes
A first jump control step for jumping by one track each time the optical disk rotates once to return the irradiation position of the laser beam by the optical pickup to the position before one rotation;
A determination step of confirming the presence of recording data based on the presence or absence of a reproduction signal of the recording data on the track after the jump in the first jump control step;
A second jump control step for causing the laser beam irradiation position by the optical pickup to jump by one track in the same direction as the movement direction of the laser beam irradiation position in the initial movement step when the presence of the recording data is confirmed in the determination step; Inspection method of optical pickup including. An optical pickup that rotates an optical disc, records inspection data on the optical disc by an optical pickup, reproduces the inspection data recorded on the optical disc by an optical pickup, evaluates a reproduction signal by the reproduction, and inspects the optical pickup. In the inspection method,
A recording jump control step for jumping the irradiation position of the laser beam on the optical disk by the optical pickup by one track;
After the jump control by the recording jump control step, a recording control step for controlling the optical pickup to record inspection data on the track after the jump;
After recording the inspection data in the recording control step, a reproduction jump control step for jumping the irradiation position of the laser beam by the optical pickup to the track in which the inspection data is recorded,
After the jump control by the playback jump control step, a playback control step for controlling the optical pickup to play back the test data recorded on the track after the jump for evaluation of the playback signal;
A repetitive control step for repeatedly performing the recording jump control step, the recording control step, the reproduction jump control step, and the reproduction control step , and
An initial moving step of initially moving the irradiation position of the laser beam by the optical pickup to a position slightly before the recording start position of the inspection data on the optical disc;
A recording data confirmation step for confirming the presence of the recording data on the optical disc based on a reproduction signal of the recording data by the optical pickup after the movement of the irradiation position of the laser beam by the initial movement step;
An optical recording apparatus in which the initial recording of the inspection data on the optical disc by the optical pickup in the recording control step is started when the recording data confirmation step no longer confirms the existence of the recording data on the optical disc. Pickup inspection method. An optical pickup that rotates an optical disc, records inspection data on the optical disc by an optical pickup, reproduces the inspection data recorded on the optical disc by an optical pickup, evaluates a reproduction signal by the reproduction, and inspects the optical pickup. In the inspection method,
A recording control step for controlling the optical pickup to continuously record inspection data on a plurality of tracks of the optical disc;
A reproduction control step for controlling the optical pickup to reproduce the recorded inspection data for a plurality of tracks one track at a time for evaluation of the reproduction signal after recording the inspection data in the recording control step ; further,
An initial moving step of initially moving the irradiation position of the laser beam by the optical pickup to a position slightly before the recording start position of the inspection data on the optical disc;
A recording data confirmation step for confirming the presence of the recording data on the optical disc based on a reproduction signal of the recording data by the optical pickup after the movement of the irradiation position of the laser beam by the initial movement step;
An optical recording apparatus in which the initial recording of the inspection data on the optical disc by the optical pickup in the recording control step is started when the recording data confirmation step no longer confirms the existence of the recording data on the optical disc. Pickup inspection method. In the inspection method of the optical pickup according to claim 11 ,
The reproduction control step includes
After recording the inspection data by the recording control step, a reproduction start jump control step for jumping the irradiation position of the laser beam by the optical pickup to the track where recording of the inspection data is started,
After the jump control at the playback start jump control step, each time the inspection data is played back from the optical disk by one track, the laser beam irradiation position by the optical pickup is set to 1 in the direction opposite to the jump direction at the playback start jump control step. An inspection method for an optical pickup including a jump control step for reproduction for jumping track by track. An optical pickup that rotates an optical disc, records inspection data on the optical disc by an optical pickup, reproduces the inspection data recorded on the optical disc by an optical pickup, evaluates a reproduction signal by the reproduction, and inspects the optical pickup. In the inspection method,
A first recording control step for controlling the optical pickup to record inspection data on one track of the optical disc;
A first reproduction control step for controlling the optical pickup and reproducing the inspection data recorded by the first recording control step for evaluation of the reproduction signal after the inspection data is recorded by the first recording control step; ,
After the reproduction of the inspection data in the first reproduction control step, the second recording for controlling the optical pickup and recording the data on the tracks of the optical disk positioned on both sides of the track on which the inspection data is recorded in the first recording control step. Control steps;
A second reproduction control step of controlling the optical pickup after the data recording by the second recording control step and reproducing the inspection data recorded by the first recording control step for the evaluation of the reproduction signal. An inspection method for an optical pickup. The optical pickup inspection method according to claim 13 , further comprising:
An initial moving step of initially moving the irradiation position of the laser beam by the optical pickup to a position slightly before the recording start position of the inspection data on the optical disc;
A recording data confirmation step for confirming that there is no recording data in at least three consecutive tracks on the optical disk based on a reproduction signal of the recording data by the optical pickup after the movement of the laser light irradiation position in the initial movement step. ,
The first recording control step is an inspection method for an optical pickup in which inspection data is recorded on a central track of three tracks where the recording data does not exist.

Images