JPH11306701A - Optical information recording and reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably move an optical pickup to a target position even when a drive load is varied due to a change in temperature atmosphere, deterioration of components composing a mechanical part with the lapse of time, or the like, in an optical information recording and reproducing apparatus which utilizes a stepping motor for moving the optical pickup. SOLUTION: An optical information recording and reproducing apparatus is constructed by providing pulse number detecting means 13 for counting the number of pulses for driving a stepping motor 7, track cross number detecting means 14 for counting the number of tracks crossed by a lens provided on an optical pickup 3, comparison means 15 for determining that synchronism is lost when a difference between the number of driving pulses and the number of track crosses reaches a predetermined value or more, and driving voltage control means 16 for varying the amplitude of a stepping motor driving voltage. Thus, when loss of synchronism is detected, an appropriate driving force is supplied to the optical pickup 3 by increasing the amplitude of the driving voltage of the stepping motor 7, thereby surely moving the optical pickup 3 at a high speed to a target position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical information recording / reproducing apparatus used for a CD-ROM drive or the like.

[0002]

2. Description of the Related Art In recent years, optical information recording / reproducing apparatuses have been required to have high-speed access performance so that an optical pickup can be moved to a target position on a disk in a short time. An optical information recording / reproducing apparatus using a stepping motor has been commercialized as a traverse motor for moving an optical pickup. The stepping motor rotates at a constant basic step angle for one drive pulse. For this reason, in the optical information recording / reproducing apparatus using the stepping motor, the moving amount of the optical pickup is easily controlled to be open, and no position detecting means for detecting the current position of the optical pickup is required. As a result, in the optical information recording / reproducing apparatus using the stepping motor, the driving mechanism for moving the optical pickup can be simplified. Further, since the stepping motor rotates in synchronization with the frequency of the drive pulse, speed control can be easily realized.

Hereinafter, a conventional optical information recording / reproducing apparatus will be described with reference to the drawings. FIG. 14 is a block diagram showing a configuration of a conventional optical information recording / reproducing apparatus. FIG.
FIG. 5 is a waveform diagram showing a frequency change waveform (pulse rate pattern) of a conventional drive pulse. In the following description, the number of pulses per second of the drive pulse signal for driving the stepping motor is called a pulse rate. FIG.
4, a disc 1 having a spiral information track
Are configured to be rotated by a spindle motor 102. Recording and reproduction of information tracks on the disc 1 are performed by the optical pickup 103. A lens 104 is mounted on the optical pickup 103.
The lens 104 is provided so as to be electromagnetically movable in a vertical direction and a horizontal direction by a focus actuator and a tracking actuator (not shown) built in the optical pickup 103, respectively. The focus servo unit 105 determines a displacement amount of the lens 104 from the disk 1 based on a focus error signal.
The focus actuator is driven so that the lens 104 keeps a fixed distance from the disk 1.

The tracking servo means 106 drives the tracking actuator so that the lens 104 follows an arbitrary track on the disk 1 based on a tracking error signal which is an amount of displacement of the lens 104 from the center of the track on the disk 1. . The stepping motor 107 moves the optical pickup 103 in the radial direction of the disk 1. The stepping motor driving means 108 applies a driving voltage to the stepping motor 107. The optical pickup position detecting means 109 is the optical pickup 1
03, the current position of the optical pickup 103 is detected from the address information included in the data read. The pulse number calculating means 110 calculates the number of stepping motor drive pulses required to move the optical pickup 103 from the current position detected by the optical pickup position detecting means 109 and a target address input from the outside. The pulse rate pattern creating unit 111 creates a frequency change (pulse rate pattern) of the pulse input to the stepping motor driving unit 108 based on the number of pulses calculated by the pulse number calculating unit 110. The lead screw 112 connects the optical pickup 103 to the disc 1
And the torque of the stepping motor 107 is transmitted to the optical pickup 103.

Next, a description will be given of an operation for sending the optical pickup 103 at a high speed in the conventional optical information recording / reproducing apparatus configured as described above. Lens 104
Is controlled by a focus servo unit 105 and a tracking servo unit 106 to read information from the disk 1 by the optical pickup 103. The focus servo means 105 is controlled so that the lens 104 always focuses on the disk 1. The tracking servo means 106 is controlled by an electromagnetic actuator (not shown) so that the lens 104 always follows the track of the disk 1.

[0006] In order to access an arbitrary track, first, the pulse number calculating means 110 detects the optical pickup 103 detected by the optical pickup position detecting means 109.
The number of pulses required to move from the current position to the target is calculated. Next, with the operation of the tracking servo means 106 stopped, the pulse rate pattern creating means 111 creates the pulse rate shown in FIG. 15 and outputs it to the stepping motor driving means 108. The pulse rate which is the number of pulses per second of the drive pulse signal for driving the stepping motor shown in FIG. 15 indicates a general drive signal pattern for driving the stepping motor. At this pulse rate, the stepping motor driving unit 108 drives the stepping motor 107 to move the optical pickup 103. After the optical pickup 103 moves to a predetermined position, the tracking servo means 106 is operated again to record and reproduce information.

[0007] The pulse rate shown in FIG. 15 is output by a pulse rate creating means 111 constituted by a microcomputer or the like. Next, the pulse rate created by the pulse rate creating means 111 will be described. As described above, since the stepping motor 107 rotates in synchronization with the frequency (pulse rate) of the driving pulse, the moving speed of the optical pickup 103 corresponds to the rotation speed of the stepping motor, that is, the frequency (pulse rate) of the driving pulse. As shown in the pulse rate of FIG. 15, when the stepping motor 107 starts from a stopped state, a frequency that can be started without step-out (called a self-starting frequency,
The output is started at a frequency indicated by level P1 in FIG. Note that step-out refers to a state in which the stepping motor 107 loses synchronization with the input pulse rate and does not rotate normally. Thereafter, the pulse rate is increased at a constant pulse rate change rate to a predetermined speed (frequency indicated by level P2 in FIG. 15). Then, after a lapse of a predetermined time at the frequency indicated by the level P2, the pulse rate is decreased so as to be symmetrical to the pulse rate increase, and the output of the pulse is stopped.

[0008]

However, in the conventional optical information recording / reproducing apparatus having the above-mentioned structure, the thrust is reduced due to a large change in the use environment temperature or the deterioration of the components of the mechanism with time. The friction load of the generated and transmitted mechanism changes from the initial design value. For this reason, there have been problems that the optical pickup cannot be moved and that the time required to move to the target position on the disk increases. This problem is solved by, for example, detecting out-of-step of the stepping motor by rotation detection means constituted by an encoder or the like, and controlling the generated torque by means such as changing the drive voltage of the motor when the out-of-step is detected. It is possible to solve. Further, the above problem can be solved by driving the stepping motor at a slow pulse rate. However, when the detection means for detecting the step-out is expensive or when the pulse rate is lowered, an adverse effect such as deterioration of the access performance occurs.

In view of the above problems, in addition to the configuration of the traverse mechanism of the conventional optical pickup, a step-out detecting means which does not require a special detector, There is a demand for an optical information recording / reproducing apparatus which does not have the above-mentioned adverse effects despite having a drive voltage control means for switching between a drive voltage and a drive pulse rate, and a pulse rate control means. That is,
SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical information recording / reproducing apparatus that enables stable and high-speed movement of an optical pickup even when a frictional load of a mechanism changes.

[0010]

In order to achieve the above object, an optical information recording / reproducing apparatus according to the present invention comprises a disk on which information is recorded on a spiral information track, and a disk on which information is recorded on the disk. Optical pickup means for reading information while following an information track; traverse means having a stepping motor for moving the optical pickup means by a predetermined distance; and pulse generation for generating a pulse signal for driving and controlling the stepping motor. Means, a stepping motor driving means for receiving the pulse signal and driving the stepping motor, step-out detecting means for detecting step-out of the stepping motor, and a step-out motor for detecting step-out of the stepping motor. When step-out is detected, the drive voltage of the stepping motor is changed. ; And a driving voltage control means for. For this reason, in the optical information recording / reproducing apparatus according to the present invention, the optical pickup can be moved stably and at high speed even when the frictional load of the mechanism changes.

According to another aspect of the present invention, there is provided an optical information recording / reproducing apparatus for reading a disk on which information is recorded on a spiral information track and reading the information recorded on the disk while following the information track. Optical pickup means, and a traverse means having a stepping motor for moving the optical pickup means by a predetermined distance,
A pulse generating means for generating a pulse signal for driving and controlling the stepping motor; a stepping motor driving means for receiving the pulse signal to drive the stepping motor; and a stepping motor for detecting step-out of the stepping motor. A step-out detection unit; and a pulse rate control unit for changing a pulse rate of an output pulse of the pulse generation unit to a predetermined pulse rate when the step-out detection unit detects a step-out of the stepping motor. I do. For this reason, in the optical information recording / reproducing apparatus according to the present invention, when the frictional load of the mechanism changes and the step-out occurs, the pulse rate is changed and the optical pickup is moved.

According to another aspect of the present invention, there is provided an optical information recording / reproducing apparatus that reads information recorded on a spiral information track and information recorded on the disk while following the information track. Optical pickup means, a traverse means having a stepping motor for moving the optical pickup means by a predetermined distance, a pulse generating means for generating a pulse signal for driving and controlling the stepping motor, and the pulse signal being inputted. A stepping motor driving means for driving the stepping motor, a step-out detecting means for detecting step-out of the stepping motor, and a number of step-outs of the stepping motor detected by the step-out detecting means. Out-of-step number storage means for performing Drive voltage control means for changing the drive voltage of the stepping motor based on the step-out number obtained, and a pulse of the output pulse of the pulse generation means based on the step-out number stored in the step-out number storage means. Pulse rate control means for changing the rate. For this reason, in the optical information recording / reproducing apparatus according to the present invention, the optical pickup moves stably and at high speed even when the frictional load of the mechanism changes.

In the optical information recording / reproducing apparatus according to the present invention, the step-out detecting means includes a track crossing number detecting means for detecting the number of tracks traversed by the optical pickup means, and an output of the pulse generating means. And a pulse number detecting means for detecting the pulse number from
The number of outputs of the pulse number detecting means and the number of outputs of the track crossing number detecting means are compared, and if the difference is equal to or greater than a predetermined value, it is determined that step-out has occurred.

Further, in the optical information recording / reproducing apparatus according to the present invention, the out-of-step detecting means includes a track crossing speed detecting means for detecting a speed at which the optical pickup means crosses a track; A pulse rate detecting means for detecting a pulse rate from an output, comparing output values of the pulse rate detecting means and the track cross speed detecting means, and when the difference is equal to or more than a predetermined value, It is configured to determine step-out.

In the optical information recording / reproducing apparatus according to the present invention, the out-of-step detecting means includes a driving current detecting means for detecting a driving current of the stepping motor;
Reference current generating means for outputting a reference value of the drive current when the stepping motor is synchronously rotating at a pulse rate output from the pulse generation means, wherein the reference value of the drive current detection means is equal to the reference value. The step-out detecting unit is configured to determine that the step-out occurs when the output value of the current generating unit becomes larger than the output value by a difference equal to or more than a predetermined value.

Further, in the optical information recording / reproducing apparatus according to the present invention, the step-out detecting means steps out while the optical pickup moves from the inner circumference to the outer circumference of the disk while following the information track. Is not determined.

Further, in the optical information recording / reproducing apparatus according to the present invention, the step-out detecting means includes an optical pickup position detecting means for detecting a position of the optical pickup from information read by the optical pickup. Target position storage means for storing a target position of the optical pickup, a storage value indicating the target position of the target position storage means, and a detection value of the optical pickup position detection means after movement of the optical pickup. And if the difference is equal to or larger than a predetermined value, it is determined that the step-out is determined.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the optical information recording / reproducing apparatus of the present invention will be described below with reference to the accompanying drawings.

<< Embodiment 1 >> Hereinafter, Embodiment 1 which is one of the preferred embodiments of the optical information recording / reproducing apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an optical information recording / reproducing apparatus according to Embodiment 1 of the present invention. FIG. 2 is a waveform diagram showing a pulse rate pattern in the optical information recording / reproducing apparatus of the first embodiment.

In FIG. 1, a disk 1 having spiral information tracks is configured to be rotated by a spindle motor 2. Recording and reproduction of information tracks on the disc 1 are performed by the optical pickup 3.
A lens 4 is mounted on the optical pickup 3. The lens 4 is provided so as to be electromagnetically movable in the vertical and horizontal directions by a focus actuator and a tracking actuator (not shown) built in the optical pickup 3, respectively. The focus servo means 5 drives the focus actuator based on a focus error signal indicating the amount of displacement of the lens 4 from the disk 1 so that the lens 4 keeps a constant distance from the disk 1. The tracking servo means 6 determines whether the lens 4 is moving from the center of the track on the disk 1 to the lens 4 based on a tracking error signal.
The tracking actuator is driven so as to follow an arbitrary track above. The stepping motor 7 moves the optical pickup 3 in the radial direction of the disk 1.

The stepping motor driving means 8 applies a driving voltage to the stepping motor 7. The optical pickup position detecting means 9 obtains the optical pickup 3 from the address information contained in the data read by the optical pickup 3.
Detect the current position of. The pulse number calculating means 10 calculates the number of stepping motor driving pulses required to move the optical pickup 3 from the current position detected by the optical pickup position detecting means 9 and a target address input from the outside. Pulse rate pattern creation means 1
1 generates a frequency change (pulse rate pattern) of an input pulse to the stepping motor driving means 8 based on the pulse number calculated by the pulse number calculating means 10. The lead screw 12 is configured to hold the optical pickup 3 movably in the radial direction of the disk 1 and transmit the torque of the stepping motor 7 to the optical pickup 3.

As shown in FIG. 1, the step-out detecting means 50 comprises:
Pulse number detecting means 13, track crossing number detecting means 1
4 and comparison means 15. The pulse number detecting means 13 is constituted by a digital circuit or a CPU for detecting the number of drive pulses output from the pulse rate pattern creating means 11. The track crossing number detecting means 14 receives a signal from the tracking servo means 6 and detects the number of tracks crossed by the optical pickup 3. The comparing means 15 is a pulse number detecting means 13
Is converted into a unit of the number of tracks in accordance with the resolution of the stepping motor 7, and the converted value is compared with the number of tracks crossed by the optical pickup 3 from the track crossing number detecting means 14. When the difference reaches a predetermined value or more, the comparing means 15 regards the loss of synchronism and outputs a loss-of-step detection signal. The drive voltage control means 16 changes the drive voltage of the stepping motor 7 into n steps (n is an integer of 2 or more) based on the step-out detection signal from the comparison means 15. Lead screw 1
Numeral 2 is configured to hold the optical pickup 3 movably in the radial direction of the disk 1 and transmit the torque of the stepping motor 7 to the optical pickup 3.

[Operation of Optical Information Recording / Reproducing Apparatus of First Embodiment] The operation of the optical information recording / reproducing apparatus of the first embodiment of the present invention configured as described above will be described. The lens 4 is controlled by a focus servo unit 5 and a tracking servo unit 6 to read information from the disk 1 by the optical pickup 3. The focus servo means 5 is controlled so that the lens 4 is always focused on the disk 1. Further, the lens 4 is controlled by the tracking servo means 6 so as to always follow the track of the disk 1. However, while the lens 4 is following the information track of the disk 1, the track cross number detecting means 1
The step-out detecting means 50, which is composed of the pulse number 4, the pulse number detecting means 13 and the comparing means 15, is in a stopped state. Next, in order to access an arbitrary track, first, the current position of the optical pickup 3 is detected. For the detection, data including address information on the disk 1 is read by the optical pickup 3. From the address information, the current position of the optical pickup 3 is detected by the optical pickup position detecting means 9. The pulse number calculating means 10 calculates the number of pulses required for moving the detected optical pickup 3 from the current position to the target track.

Next, while the operation of the tracking servo means 6 is stopped, a pulse rate as shown in FIG. 2 is created by a pulse rate pattern creating means 11 constituted by a microcomputer or the like, and this pulse rate is stepped. Output to the motor driving means 8. The stepping motor driving means 8 drives the stepping motor 7 at the input pulse rate to move the optical pickup 3. After the optical pickup 3 moves to a predetermined position, the tracking servo means 6 is operated again to record and reproduce information.

While the pickup 3 is moving, the pulse number detecting means 13 is operated by the pulse rate pattern creating means 11.
It is counted up according to the output of. Further, the track cross number detecting means 14 counts the number of tracks crossed by the lens 4 according to the movement of the optical pickup 3. When the stepping motor 7 is rotating synchronously with the output pulse of the pulse rate pattern creating means 11, the amount of rotation of the stepping motor 7 and the amount of movement of the optical pickup 3 correspond. Therefore, the output of the pulse number detecting means 13 corresponds to the movement amount of the optical pickup 3, and the output of the track cross number detecting means 14 outputs a value corresponding to the movement amount of the lens 4. Therefore, the difference between the amount of movement of the optical pickup 3 and the amount of movement of the lens 4 is within the movable range of the lens 4 with respect to the optical pickup 3.

Next, a case where the stepping motor 7 is out of synchronization (step-out) will be described. in this case,
The pulse number detector 13 counts up according to the output of the pulse rate pattern generator 11. However, since the optical pickup 3 does not move a predetermined distance, the track crossing number detecting means 14 does not count the number of crossed tracks. As a result, the output difference between the pulse number detecting means 13 and the track cross number detecting means 14 increases. This output difference is measured by the comparing means 15, and when the output difference is large, it is determined that the step-out state has occurred. When the comparing means 15 determines that the step-out state has occurred, the comparing means 15 outputs a step-out detection signal to the drive voltage control means 16. The drive voltage control means 16 to which the step-out detection signal is input
Increases the voltage for driving the stepping motor 7. Therefore, the generated torque of the stepping motor 7 increases, and the step-out state due to the fluctuation of the driving load is recovered.

The optical information recording / reproducing apparatus according to the first embodiment is configured as described above. Therefore, when the driving load fluctuates due to the change of the temperature environment and the aging of the components constituting the mechanism, etc. A step-out of the stepping motor 7 is detected, and the drive voltage of the stepping motor 7 is controlled. As a result, in the optical information recording / reproducing apparatus of the first embodiment, an optimal driving force can be transmitted to the optical pickup 3, and the optical pickup 3 can be moved at a high speed.

Embodiment 2 An optical information recording / reproducing apparatus according to a second embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a block diagram showing a configuration of an optical information recording / reproducing apparatus according to Embodiment 2 of the present invention. In the second embodiment, components having the same configurations and functions as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIG. 3, the out-of-step detecting means 60 according to the second embodiment includes a pulse rate detecting means 17, a track cross speed detecting means 18, and a comparing means 19. The pulse rate detecting means 17 is constituted by a digital circuit or a CPU or the like, and detects the frequency (pulse rate) of the driving pulse output from the pulse rate pattern creating means 11. The track cross speed detecting means 18 receives a signal from the tracking servo means 6 and detects the relative speed of the lens 4 to the track from the number of tracks crossed by the optical pickup 3 and the required time at that time. The comparing means 19 converts the output of the pulse rate detecting means 17 into the same unit as the track cross speed according to the resolution of the stepping motor 7, and compares the converted value with the output of the track cross speed detecting means 18. When the difference between the conversion value and the track crossing speed detecting means 18 reaches a predetermined value or more, the comparing means 19 regards the out-of-step as a loss and outputs a out-of-step detecting signal. The drive voltage control means 16 changes the drive voltage of the stepping motor 7 in n steps (n is 2
To the above integer).

[Operation of Optical Information Recording / Reproducing Apparatus According to Second Embodiment] The operation of the optical information recording / reproducing apparatus according to the second embodiment of the present invention configured as described above will be described. The lens 4 is controlled by a focus servo unit 5 and a tracking servo unit 6 to read information from the disk 1 by the optical pickup 3. The focus servo means 5 is controlled so that the lens 4 is always focused on the disk 1. Further, the lens 4 is controlled by the tracking servo means 6 so as to always follow the track of the disk 1. However, while the lens 4 follows the information track of the disk 1, the step-out detecting means 60 constituted by the track cross speed detecting means 18, the pulse rate detecting means 17 and the comparing means 19 is in a stopped state.

Next, in order to access an arbitrary track, first, the current position of the optical pickup 3 is detected.
For the detection, data including address information on the disk 1 is read by the optical pickup 3. From the address information, the current position of the optical pickup 3 is detected by the optical pickup position detecting means 9. The pulse number calculating means 10 calculates the number of pulses required for moving the detected optical pickup 3 from the current position to the target track.

Next, in a state where the operation of the tracking servo means 6 is stopped, a pulse rate pattern creating means 11 constituted by a microcomputer or the like creates a pulse rate as shown in FIG. Output to the driving means 8. The stepping motor driving means 8 drives the stepping motor 7 using the input pulse rate, and moves the optical pickup 3. After the optical pickup 3 moves to a predetermined position, the tracking servo means 6 operates again to record and reproduce information. During the movement of the optical pickup 3, the pulse rate detecting means 17 detects the speed at the pulse rate shown in FIG. The track cross speed detecting means 18 measures the number of tracks crossed by the lens 4 while the optical pickup 3 is moving, and detects the speed of the optical pickup 3. When the stepping motor 7 is rotating synchronously with the output pulse of the pulse rate pattern 11, the rotation speed of the stepping motor 7 corresponds to the moving speed of the optical pickup 3. The output of the pulse rate detecting means 17 indicates the moving speed of the optical pickup 3.
The output of the track cross speed detecting means 18 indicates the moving speed of the lens 4. For this reason, the difference between the moving speed of the optical pickup 3 and the moving speed of the lens 4 falls within a certain range.

Next, a case where the stepping motor 7 loses synchronization (step-out) will be described. The pulse rate detecting means 17 includes a pulse rate pattern creating means 11
, The speed in the pulse rate pattern shown in FIG. 2 is detected. However, when the synchronization is lost (step-out), the track cross speed detecting means 18 stops the optical pickup 3, so that the number of tracks traversed by the lens 4 disappears, and the speed of the lens 4 approaches zero. As a result, the output difference between the pulse rate detecting means 17 and the track cross speed detecting means 18 becomes large, and the comparing means 19 detects the out-of-step and outputs a out-of-step detecting signal to the drive voltage control means 16. The drive voltage control means 16 to which the step-out detection signal is input increases the voltage for driving the stepping motor 7. Therefore, the generated torque of the stepping motor 7 increases, and the step-out state due to the fluctuation of the driving load is recovered. Since the optical information recording / reproducing apparatus of the second embodiment is configured as described above, when the driving load fluctuates due to the change of the temperature environment and the aging degradation of the components constituting the mechanism, the stepping motor 7 Step out is detected,
The drive voltage of the stepping motor 7 is controlled. Thus, the optical information recording / reproducing apparatus according to the second embodiment can transmit an optimal driving force to the optical pickup 3, and can move the optical pickup 3 at high speed.

Embodiment 3 Hereinafter, an optical information recording / reproducing apparatus according to a third embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a block diagram illustrating a configuration of an optical information reproducing apparatus according to the third embodiment. FIG. 5 shows a pulse rate pattern (a) input to the stepping motor 7 according to the third embodiment, a current waveform (b) flowing through the stepping motor 7 when step-out does not occur, and the optical pickup 3 when step-out occurs.
And the current waveform (d) flowing through the stepping motor 7 when the step-out occurs. In the third embodiment, components having the same configurations and functions as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIG. 4, the step-out detecting unit 70 in the third embodiment includes a driving current detecting unit 20, a reference current creating unit 21, and a comparing unit 22. The drive current detecting means 20 is connected to the stepping motor 7
The amount of current supplied to the power supply is detected. Reference current creating means 21
Outputs a signal representing a reference current amount according to the frequency of the pulse output from the pulse rate pattern creating means 11 and the power supply voltage supplied to the stepping motor 7 from the drive voltage control means 16. The comparing means 22 compares the output value of the driving current detecting means 20 with the output value of the reference current generating means 21, and when the difference reaches a predetermined value or more, it is regarded as out-of-step. Output to control means 16. The drive voltage control means 16 changes the drive voltage of the stepping motor 7 to n steps (n is an integer of 2 or more) based on the step-out detection signal of the comparison means 22 of the step-out detection means 70.

[Operation of Optical Information Recording / Reproducing Apparatus According to Third Embodiment] The operation of the optical information recording / reproducing apparatus according to the third embodiment of the present invention configured as described above will be described. The lens 4 is controlled by a focus servo unit 5 and a tracking servo unit 6 to read information from the disk 1 by the optical pickup 3. The focus servo means 5 is controlled so that the lens 4 is always focused on the disk 1. Further, the lens 4 is controlled by the tracking servo means 6 so as to always follow the track of the disk 1. However, while following the track of the disk 1, the drive current detecting means 20 and the reference current generating means 21
And the step-out detecting means 70 constituted by the comparing means 22 are in a stopped state.

Next, in order to access an arbitrary track, first, the current position of the optical pickup 3 is detected.
For the detection, data including address information on the disk 1 is read by the optical pickup 3. From the address information, the current position of the optical pickup 3 is detected by the optical pickup position detecting means 9. The pulse number calculating means 10 calculates the number of pulses required for moving the detected optical pickup 3 from the current position to the target track. Next, in a state where the operation of the tracking servo means 6 is stopped, the pulse rate shown in FIG. 5A is created by the pulse rate pattern creating means 11 constituted by a microcomputer or the like, and this pulse rate is set to a stepping motor. Output to the driving means 8. The stepping motor driving means 8 drives the stepping motor 7 at the input pulse rate to move the optical pickup 3.
After the optical pickup 3 moves to a predetermined position, the tracking servo means 6 operates again to record and reproduce information.

FIG. 5B shows the amount of current flowing to the stepping motor 7 on the horizontal axis while the optical pickup 3 is moving in the traverse mechanism of the third embodiment. The motor current pattern shown in FIG. 5B shows a case where no step-out occurs. The driving voltage applied by the driving voltage control means 16 to the stepping motor 7 by the stepping motor driving means 8 is V1, and the stepping motor 7 determined by the rotation speed of the stepping motor 7
Assuming that the back electromotive force Ea generated in the stepping motor 7 and the resistance value of the stepping motor 7 are R, (V1-
Ea) A current I represented by / R flows. In the optical information recording / reproducing apparatus according to the third embodiment, the reference current creating means 21 has a relation between the resistance value of the stepping motor 7 and the rotation speed of the stepping motor 7 and the back electromotive force in advance as a table or a calculation formula. Reference current creating means 21
Calculates a reference current based on the output value of the drive voltage control means 16 and the pulse rate output by the pulse rate pattern creation means 11, and outputs the calculated value. When the stepping motor 7 is rotating synchronously with the output pulse of the pulse rate pattern creating means 11, the driving current detecting means 2
Both the detected value of 0 and the output of the reference current generating means 21 output (V1-Ea) / R, and this difference falls within a fixed value.

Next, the case where the stepping motor 7 is out of synchronization (step-out) will be described. As shown in FIG. 5C, when the step-out occurs, the rotation speed of the stepping motor 7 becomes lower than the command value (pulse rate) from the pulse rate pattern creating means 11. Therefore, the back electromotive voltage generated in the stepping motor 7 is Ea ′.
Has a relationship of Ea ′ <Ea. Stepping motor 7
, A current as shown in FIG. 5D flows through the motor.
For this reason, the step-out is detected by the comparing unit 22, and the comparing unit 22 outputs a step-out detection signal to the drive voltage control unit 16. When the out-of-step detection signal is input, the drive voltage control means 16 increases the voltage for driving the stepping motor 7, increases the torque generated by the stepping motor 7, and recovers the out-of-step state due to the fluctuation of the driving load.

The optical information recording / reproducing apparatus according to the third embodiment having the above-described configuration is capable of controlling the stepping motor 7 when the driving load fluctuates due to the change of the temperature environment and the aging of components constituting the mechanism. Out of step is detected, and the drive voltage of the stepping motor 7 is controlled. Thus, the optical information recording / reproducing apparatus according to the third embodiment can transmit the optimal driving force to the optical pickup 3, and can move the optical pickup 3 at high speed.

Embodiment 4 An optical information recording / reproducing apparatus according to Embodiment 4 of the present invention will be described below with reference to the drawings. FIG. 6 is a block diagram illustrating a configuration of an optical information reproducing apparatus according to the fourth embodiment. FIG. 7 is a flowchart in the step-out detection operation of the optical information reproducing apparatus according to the fourth embodiment. In the fourth embodiment, components having the same configurations and functions as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIG. 6, the out-of-step detection unit 80 of the fourth embodiment includes a target address storage unit 23, an arrival address storage unit 24, and a comparison unit 25. The target address storage means 23 stores a target address input from outside. The arrival address storage means 24 stores the output of the optical pickup position detecting means 9 from the optical pickup 3
Is stored. The comparing means 25 compares the output value of the target address storage means 23 with the arrival address storage means 2
4, and when the difference reaches a predetermined value or more, it is regarded as a step-out, and the step-out detection signal is output to the drive voltage control means 1.
Output to 6. The drive voltage control means 16 is a step-out detection means 8
The drive voltage of the stepping motor 7 is changed to n stages (n is an integer of 2 or more) based on the out-of-step detection signal of the comparison means 25 of 0.

As described above, when the stepping motor 7 steps out, the stepping motor 7 cannot rotate synchronously with the input pulse, and stops rotating. For this reason, the optical pickup 3 stops before the target position. Conversely, if the step-out does not occur, the optical pickup 3 moves to the target position, and the error of the movement of the lens 4 from the target position after the movement falls within the movable range of the lens 4 with respect to the optical pickup 3. Therefore, in the optical information recording / reproducing apparatus according to the fourth embodiment, the out-of-step is detected by comparing the target address and the arrival address.

[Step-out detection operation in optical information recording / reproducing apparatus of Embodiment 4] Step-out detection operation in the optical information recording / reproducing apparatus of Embodiment 4 of the present invention will be described. Since the lens 4 reads information from the disk 1 by the optical pickup 3, the lens 4 is provided with a focus servo unit 5.
And the tracking servo means 6. The focus servo means 5 is controlled so that the lens 4 always focuses on the disk 1. Further, the lens 4 is controlled by the tracking servo means 6 so as to always follow the track of the disk 1.

Next, the out-of-step detection operation in the optical information recording / reproducing apparatus of the fourth embodiment will be described with reference to the flowchart of FIG. To access any track,
The current position of the optical pickup 3 is detected. For this purpose, data including address information on the disk 1 is read by the optical pickup 3. From that address information,
The current position of the optical pickup 3 is detected by the optical pickup position detecting means 9 (step S1). The pulse number calculation means 10 calculates the number of pulses required to move the detected optical pickup 3 from the current position to the target address (step S2). The target address is stored in the target address storage means 23 (step S3).

Next, the operation of the tracking servo means 6 is stopped (step S4). Then, in the pulse rate pattern creating means 11 constituted by a microcomputer or the like, the pulse rate shown in FIG. 2 is created, and this pulse rate is output to the stepping motor driving means 8. The stepping motor driving means 8 drives the stepping motor 7 at this pulse rate to move the optical pickup 3 (step S5). The optical information recording / reproducing apparatus of the fourth embodiment generates a predetermined number of pulses to move the optical pickup 3 by a predetermined distance, and then operates the tracking servo means 6 again to follow the track of the disk 1 with the lens 4. (Step S6). Further, the arrival address of the optical pickup 3 is read and stored in the arrival address storage means 24 (step S7).

The moving error is calculated by the comparing means 25 from the values stored in the target address storing means 23 and the arrival address storing means 24 (step S8). Then, the comparing means 25 compares the reference movement error amount, which is the movable amount of the lens 3, with the calculated movement error amount, and determines that the step-out occurs only when the movement error amount is equal to or more than the reference movement error amount (step S9). ,
A step-out detection signal is output to the drive voltage control means 16 (step S10). The drive voltage control means 16 to which the step-out detection signal is input increases the voltage for driving the stepping motor 7. Therefore, the generated torque of the stepping motor 7 increases, and the step-out state due to the fluctuation of the driving load is recovered. Since the optical information recording / reproducing apparatus of the fourth embodiment is configured as described above, when the drive load fluctuates due to the change of the temperature environment and the aging of the components constituting the mechanism, the stepping motor 7 The step-out is detected and the drive voltage of the stepping motor 7 is controlled. As a result, the optical information recording / reproducing apparatus according to the fourth embodiment has the optical pickup 3
And the optical pickup 3 can be moved at high speed.

Embodiment 5 Hereinafter, Embodiment 5 of the optical information recording / reproducing apparatus of the present invention will be described with reference to the drawings. FIG. 8 is a block diagram illustrating a configuration of an optical information reproducing apparatus according to the fifth embodiment. In the fifth embodiment, components having the same configurations and functions as those in the fourth embodiment are denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, a description will be given of a portion of the fifth embodiment that is different from the optical information recording / reproducing apparatus of the fourth embodiment. In FIG. 8, the pulse rate pattern control means 26 changes the pulse rate pattern of the pulse rate pattern creation means 11 to m (m is an integer of 2 or more) stages based on the step-out detection signal of the step-out detection means 80.

[Operation of Optical Information Recording / Reproducing Apparatus of Fifth Embodiment] The operation of the optical information recording / reproducing apparatus of the fifth embodiment of the present invention configured as described above will be described. The fifth embodiment is different from the fourth embodiment in that the drive voltage of the stepping motor 7 is not increased when the step-out is detected, but the maximum speed of the pulse rate output from the pulse rate pattern creating means 11 is different. And lower the acceleration. FIG. 9 shows the relationship between the pulse rate pattern and the torque before step-out detection in the fifth embodiment. When the stepping motor 7 is driven by the pulse rate pattern K1 shown in FIG. 9A, acceleration and deceleration require a torque T1 proportional to the acceleration shown in FIG. 9B. Further, a constant torque T2 shown in FIG. 9C is required during driving by the friction load. When the stepping motor 7 is driven at a constant voltage, the torque T3 generated by the stepping motor 7 decreases as the speed increases, as shown in FIG. 9D. When the friction load fluctuates, if the torque T3 generated by the stepping motor 7 becomes smaller than the sum of the torque T1 required for acceleration and the friction load torque T2, the torque becomes insufficient and the stepping motor 7 steps out.

FIG. 10 shows the relationship between the pulse rate pattern K2 after step-out detection and torque in the fifth embodiment. When step-out is detected, the speed and acceleration of the pulse rate output from the pulse rate pattern creating means 11 are changed to the pulse rate pattern K2 shown in FIG. It is made smaller than the pulse rate pattern K1 shown. By reducing the acceleration in this way, the torque T1 'required for acceleration can be reduced. Further, by lowering the maximum speed, the torque T3 'generated by the stepping motor increases as shown in FIG. Accordingly, a margin for the total torque of the torque T1 'required for acceleration and the friction load torque T2' in the generated torque T3 'is increased.
As a result, in the optical information recording / reproducing apparatus according to the fifth embodiment, it is possible to recover from a step-out state due to a change in driving load.

In the fifth embodiment, the out-of-synchronization is detected by using the out-of-step detection means 80 shown in the fourth embodiment. However, the present invention is not limited to this.
Out-of-step detection means 50 used in the first to third embodiments,
The same effect can be obtained by using 60 and 70.
Since the optical information recording / reproducing apparatus of the fifth embodiment is configured as described above, even if the driving load fluctuates due to the change of the temperature environment and the aging deterioration of the components constituting the mechanism, the stepping motor 7 can be used. Is detected, and the drive pulse rate of the stepping motor 7 is controlled. Thereby, the optimal driving force can be transmitted to the optical pickup 3, and the optical pickup 3 can be reliably moved to the target position.

Embodiment 6 Next, Embodiment 6 of the optical information recording / reproducing apparatus of the present invention will be described with reference to the drawings. FIG. 11 is a block diagram showing a configuration of an optical information recording / reproducing apparatus according to Embodiment 6 of the present invention. In Example 6,
Components having the same configuration and function as those of the fourth embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the above-described first to fourth embodiments of the present invention, the drive voltage of the stepping motor 7 is increased every time step-out is detected, so that the generated torque of the stepping motor 7 is increased to reduce the fluctuation of the friction load. Yes, it is. However, in such a configuration, the temperature of the stepping motor 7 increases as the drive voltage increases. Further, in the optical information recording / reproducing apparatus according to the fifth embodiment of the present invention, the speed and acceleration of the pulse rate of the stepping motor 7 are reduced every time a step-out is detected, so that the torque required for rotation is reduced to reduce the frictional load. Respond to fluctuations. However, in this configuration, the moving time is significantly slowed down as the pulse rate decreases. An optical information recording device that solves such a problem is described in Embodiment 6 of the present invention.
Optical information recording and reproducing apparatus.

Next, a description will be given of a portion of the sixth embodiment which is different from the optical information recording / reproducing apparatus of the fourth embodiment. In FIG. 11, the step-out frequency determining unit 27 counts the number of steps out based on the step-out detection signal output from the comparing unit 25 in the step-out detecting unit 80. The step-out frequency determination unit 27 has a step-out frequency storage unit (not shown), and the step-out frequency storage unit stores the counted step-out frequency. The step-out frequency determination means 27 is based on the step-out detection signal and the signal output from the step-out frequency storage means.
6 and the pulse rate pattern control means 26 are controlled.
In the optical information recording / reproducing apparatus of the sixth embodiment, the drive voltage control means 16 and the pulse rate pattern control means 26 are controlled not by the output of the comparison means 25 but by the output of the step-out frequency determination means 27. FIG. 12 is a flowchart showing the control operation of the drive voltage control means 16 and the pulse rate pattern control means 26 by the step-out frequency storage means 27 after step-out detection in the optical information recording / reproducing apparatus of the sixth embodiment. FIG.
3 is a pulse rate pattern creating means 1 in the sixth embodiment.
FIG. 2 is a waveform diagram showing a pulse rate pattern created and output in FIG.

[Operation of Optical Information Recording / Reproducing Apparatus of Sixth Embodiment] The operation of the optical information recording / reproducing apparatus of the sixth embodiment of the present invention configured as described above will be described with reference to the flowchart of FIG. . The operation is the same as that of the fourth embodiment until the optical pickup 3 is moved (step S1) and it is determined whether or not step-out occurs. Optical pickup 3
Is moved, the step-out frequency determining means 27 determines whether or not step-out has occurred (step S2). If the step-out has not occurred, the movement of the optical pickup 3 is terminated. If step-out has occurred, the number of step-outs is counted (step S3). The pulse rate pattern control means 26 sets the pulse rate pattern K3 shown in FIG.
4). The maximum rate and the acceleration of the pulse rate pattern K3 are sufficiently smaller than those of the pulse rate pattern K1 shown in FIG. Then, the optical pickup 3 is moved by the remaining distance (step S5).

If the step-out has occurred, the following processing is performed according to the number of steps-out. If the number of step-outs is less than N1 (N1 is an integer of 1 or more) (step S6), the pulse rate pattern setting is returned to K1, and the movement of the optical pickup 3 is terminated (step S7). Step-out frequency is N
When it is not less than 1 and less than N2 (N2 is an integer not less than N1) (step S8), the drive voltage control means 16 sets the drive voltage of the stepping motor 7 to h2 (h2> initial value h1).
(Step S9). Then, the pulse rate pattern control means 26 sets the pulse rate pattern to K
1 to end the movement of the optical pickup 3 (step S7). The number of steps out is N2 or more, N3 (N3 is N2
If it is less than the above integer (steps S10 and S11), the drive voltage of the stepping motor 7 is returned to the initial value h1 by the drive voltage control means 16 (step S1).
2). Then, the pulse rate pattern control means 26 sets the pulse rate pattern K2 shown in FIG. 13B, and ends the movement of the optical pickup 3 (step S13). The pulse rate pattern K2 is such that the maximum speed and acceleration are between the pulse rate patterns K1 and K3. If the number of steps out is N3 or more (step S1
0), the movement of the optical pickup 3 ends with the setting state of the pulse rate pattern K3 set in step S4.

Since the optical information recording / reproducing apparatus of the sixth embodiment is configured as described above, when the driving load fluctuates due to the change of the temperature environment and the aging of the components constituting the mechanism, the stepping is performed. The step-out of the motor 7 is detected, and the drive voltage and the drive pulse rate of the stepping motor 7 are controlled. Thus, the optical information recording / reproducing apparatus according to the sixth embodiment can transmit the optimum driving force to the optical pickup 3 and reliably move the optical pickup 3 to the target position at high speed while keeping the temperature of the stepping motor 7 constant. Can be moved. In the sixth embodiment, the step-out detection means 8 shown in the fourth embodiment is used for step-out detection.
However, the present invention is not limited to this. Even when the step-out detecting means 50, 60, and 70 used in the first to third embodiments are used, the same configuration as that of the sixth embodiment is used. The effect can be obtained. In the sixth embodiment, the driving voltage can be switched in two stages and the pulse rate pattern can be switched in three stages. However, by increasing the number of switching stages, the stability of the movement of the optical pickup 3 can be further improved. It is possible to increase the speed.

[0054]

As described above, the optical information recording / reproducing apparatus according to the present invention is capable of removing the stepping motor even when the driving load fluctuates due to the change of the temperature environment and the aging of the components constituting the mechanism. By controlling the driving voltage and driving pulse rate of the stepping motor, the optimum driving force is transmitted to the optical pickup, and the optical pickup is reliably moved to the target position at high speed while keeping the temperature of the stepping motor constant. It is possible to move to.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an optical information recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram showing a stepping motor drive pulse rate according to the first embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of an optical information recording / reproducing device according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of an optical information recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 5 is a waveform diagram showing a stepping motor driving pulse rate and a current flowing through the stepping motor according to a third embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration of an optical information recording / reproducing device according to a fourth embodiment of the present invention.

FIG. 7 is a flowchart of step-out detection according to a fourth embodiment of the present invention.

FIG. 8 is a block diagram illustrating a configuration of an optical information recording / reproducing device according to a fifth embodiment of the present invention.

FIG. 9 is a waveform diagram showing a stepping motor driving pulse rate and a motor generated torque in a fifth embodiment of the present invention.

FIG. 10 is a waveform diagram showing a stepping motor drive pulse rate and a motor generated torque in a fifth embodiment of the present invention.

FIG. 11 is a block diagram illustrating a configuration of an optical information recording / reproducing apparatus according to a sixth embodiment of the present invention.

FIG. 12 is a flowchart showing an operation of the optical information recording / reproducing apparatus in Embodiment 6 of the present invention.

FIG. 13 is a waveform diagram showing a stepping motor drive pulse rate in Embodiment 6 of the present invention.

FIG. 14 is a block diagram showing a configuration of a conventional optical information recording / reproducing device.

FIG. 15 is a waveform diagram showing a conventional stepping motor drive pulse rate.

[Explanation of symbols]

 Reference Signs List 1 disc 3 optical pickup 7 stepping motor 8 stepping motor driving means 11 pulse rate pattern creating means 12 lead screw 16 drive voltage control means 50 step-out detecting means

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shuichi Yoshida 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (8)

[Claims] 1. A disc on which information is recorded on a spiral information track, an optical pickup means for reading the information recorded on the disc while following the information track, and moving the optical pickup means by a predetermined distance Traversing means having a stepping motor; pulse generating means for generating a pulse signal for controlling the driving of the stepping motor; stepping motor driving means for receiving the pulse signal to drive the stepping motor; step-out of the stepping motor. Out-of-step detection means for detecting the stepping motor, and drive voltage control means for changing the drive voltage of the stepping motor when the step-out motor detects step-out of the stepping motor. Optical information recording and reproducing apparatus. 2. A disc on which information is recorded on a spiral information track; an optical pickup means for reading information recorded on the disc while following the information track; and moving the optical pickup means by a predetermined distance. Traversing means having a stepping motor; pulse generating means for generating a pulse signal for controlling the driving of the stepping motor; stepping motor driving means for receiving the pulse signal and driving the stepping motor; step-out of the stepping motor. And a pulse rate for changing the pulse rate of the output pulse of the pulse generation means to a predetermined pulse rate when step-out of the stepping motor is detected by the step-out detection means. Control means; Optical information recording and reproducing apparatus. 3. A disc on which information is recorded on a spiral information track, an optical pickup means for reading information recorded on the disc while following the information track, and moving the optical pickup means by a predetermined distance. Traversing means having a stepping motor; pulse generating means for generating a pulse signal for controlling the driving of the stepping motor; stepping motor driving means for receiving the pulse signal and driving the stepping motor; step-out of the stepping motor. Step-out detecting means for detecting the step-out number; step-out number storing means for storing the number of step-outs of the stepping motor detected by the step-out detecting means; step-out stored in the step-out number storing means. Change the drive voltage of the stepping motor based on the number of times And a pulse rate control means for changing a pulse rate of an output pulse of the pulse generation means based on the number of step-outs stored in the step-out number storage means. Characteristic optical information recording / reproducing device. 4. The step-out detecting means includes a track crossing number detecting means for detecting the number of tracks crossed by the optical pickup means, and a pulse number detecting means for detecting a pulse number from an output of the pulse generating means. And comparing the numbers of outputs of the pulse number detecting means and the track crossing number detecting means with each other, and determining that step-out occurs when the difference is equal to or greater than a predetermined value. ,
4. The optical information recording / reproducing apparatus according to 2 or 3. 5. The step-out detecting means includes a track crossing speed detecting means for detecting a speed at which the optical pickup means crosses a track, and a pulse rate detecting means for detecting a pulse rate from an output of the pulse generating means. Means for comparing the respective output values of the pulse rate detecting means and the track cross speed detecting means, and when the difference is equal to or greater than a predetermined value, is determined to be out of step. 4. The optical information recording / reproducing device according to 2 or 3. 6. The step-out detecting means includes: a drive current detecting means for detecting a drive current of the stepping motor; and a stepping motor synchronously rotating at a pulse rate output from the pulse generating means. And a reference current generating means for outputting a reference value of the driving current. If the reference value of the driving current detecting means is larger than the output value of the reference current generating means by a difference equal to or more than a predetermined value, 4. The optical information recording / reproducing apparatus according to claim 1, wherein the key detection means is configured to determine that the key is out of synchronization. 7. The out-of-step detecting means is configured not to determine out-of-step while the optical pickup moves from the inner circumference to the outer circumference of the disk while following an information track. Or the optical information recording / reproducing apparatus according to 6. 8. An optical pickup position detecting means for detecting a position of the optical pickup from information read by the optical pickup, and a step-out detecting means for storing a target position of the optical pickup. A target position storage unit, and compares a storage value indicating a target position of the target position storage unit with a detection value of the optical pickup position detection unit after the movement of the optical pickup. 4. The optical information recording / reproducing apparatus according to claim 1, wherein the optical information recording / reproducing apparatus is configured to determine that a step-out occurs when the optical information is lost.