JPH01245434A - One-track jump automatic adjuster - Google Patents

Abstract

PURPOSE:To automatically adjust a one-track jump by providing a driving means which causes an optical head to jump from an arbitrary track to the next track but one, a discriminating means which discriminates whether the jump of the head is well made or not and an adjusting means which adjusts automatically the jumping acceleration of the driving means. CONSTITUTION:The driving means 15, discriminating means 16, and adjusting means 17 are provided. The means 15 causes the optical head to jump from an arbitrary track to the next track but one on an information recording medium and the discriminating means 16 discriminates whether the jump of the head is well made or not by comparing a track error signal from a track error detecting means which detects the coming-off of the optical head from a track on the information recording medium with a positive or negative constant voltage when the jump is completed. The adjusting means 17 adjusts the jumping acceleration of the driving means 15 in accordance with a discriminated result of the discriminating means 16. Therefore, adjustment of the one-track jump of the optical head on the information recording medium is automatically performed without manual operations.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a one-track jump automatic adjustment device in an optical information recording/reproducing device.

(Prior art) In optical information recording and reproducing devices such as optical disk devices and magneto-optical disk devices, an optical head directs a light beam onto an information recording medium consisting of an optical disk or a magneto-optical disk in which tracks are formed in a spiral or concentric pattern. It optically records and/or reproduces information by irradiating it through a lens, and has a one-track jump drive circuit.

As shown in Fig. 24, this one-track jump drive circuit uses an open-loop bang-bang control method, and creates an input voltage Vin (V) by dividing the constant voltage of a constant voltage source using a resistor 1 and a variable resistor 2. When the objective lens is caused to jump from any track on the information recording medium to the next track, the microcomputer 3 turns on the switches 4.5 for a fixed period of time T. As a result, the operational amplifier 6 receives the input voltage Vin (V) through the switch 4, and the input voltage Vin (V) is inverted by the inverter 7 and input through the switch 5, resulting in an addition as shown in FIG. A deceleration pulse is generated, and this acceleration/deceleration pulse is amplified by a power amplifier 8. A circuit consisting of transistors 9 and 10 and resistors 11 to 13 causes the track motor 14 to perform forward and reverse rotation in accordance with the output voltage of the power amplifier 8, and the track motor 14 rotates the objective lens as shown in FIG. By moving the information recording medium in a direction perpendicular to the tracks on the information recording medium at a speed v (m/s), the information on the objective lens is jumped from any track on the information recording medium to the next track. A track error signal as shown in FIG. 23 is obtained from a track error detection means for detecting a deviation with respect to a track on a recording medium.

Here, the force applied to the track motor 14 is F (N), the mass of the movable part including the objective lens is M (kg), the thrust constant of the track motor 14 is Kft (N/A), and the gain of the power amplifier 8 is P A , (A/V), the acceleration of the jump is a (m/s"), and the gain of the operational amplifier 6 is B.
If so.

F (N) ” M (kg) ・a (m/52) =
Vin (V)・B-P A (A/V)・Kft(
N/A)...(1), and the movement (jump) distance of the objective lens X(n
, ) is a minute displacement and becomes X(m)=aL2/2 (2). From this equation (2), the moving distance
(m) Public a...(3) It can be expressed as. This moving distance X (m) refers to the track pitch of the information recording medium and is a constant value.

Therefore, the jump acceleration a (m/s") must also be kept constant. However, in reality, there are variations in the constant voltage of the constant voltage source, variations in the resistance around the operational amplifier 6, and the gain P A (A/V ), the thrust constant Kft (N/A) of the track motor 14, the mass M (kg) of the movable part, etc. -It varies from machine to machine. As a result, the moving distance X (
m) will vary, resulting in poor settling after the jump, and in the worst case, tracking will not be possible or tracking will occur to a different track. From the above, each optical information recording/reproducing device performs one track jump as described above on the production line, and while observing the track error signal with an oscilloscope, the input voltage V in ( V) must be adjusted so that the track error signal becomes as shown in FIG. Moreover, when the board containing the one-track jump drive circuit is replaced for repair in an optical information recording/reproducing device that is already on the market, the optical information recording/reproducing device must be brought back to absorb the various variations mentioned above. The input voltage V
The current situation is that in (V) must be adjusted.

(Objective) The present invention eliminates the above-mentioned drawbacks and provides 1. regarding an optical information recording/reproducing device. To provide a one-track jump automatic adjustment device that automatically adjusts track jumps and eliminates the need for humans.

(Structure) The present invention relates to an optical information recording and reproducing apparatus that uses an optical head to optically record and/or reproduce information on an information recording medium in which tracks are formed in a spiral or concentric pattern as shown in FIG. , a driving means 15, a determining means 16, and an adjusting means 17.

The driving means 15 causes the optical head to jump from any track on the information recording medium to the next track, and the determining means 16 includes track error detection means for detecting a deviation of the optical head from a track on the information recording medium. The track error signal from the jump is compared with positive and negative constant voltages at the end of the jump to determine whether the jump is good or bad. The adjusting means 17 automatically adjusts the jump acceleration of the driving means 15 according to the determination result of the determining means 16.

The present invention will be described in detail below with reference to the drawings.

FIG. 2 shows an embodiment of the invention.

This embodiment is provided integrally with the above-mentioned optical information recording/reproducing apparatus, executes one track jump a plurality of times, and automatically adjusts the jump acceleration based on the distribution of variations in the state of the jump. In this embodiment the reference pulse generator 21. Mono multi vibrator 22. The switch 23 and the low-pass filter 24 obtain a constant voltage Vr using a frequency/voltage conversion method. That is, the reference pulse generator 21 generates a reference pulse of a predetermined frequency, and this reference pulse triggers the mono-multivibrator 22 to generate a pulse of a predetermined pulse width. Output pulse. This pulse closes the switch 23, and the constant voltage Vof of the constant voltage source passes through the switch 23 and the low-pass filter 24 and becomes a constant voltage ■r. microcomputer 47
As shown in FIG. 5, the reference pulse frequency of the reference pulse generator 21 and the pulse width of the mono-multivibrator 22 are first set so that this constant voltage Vr becomes an ideal value.

Next, the microcomputer 47 turns on the switch 25 for a certain period of time T in order to actually execute one track jump multiple times.
When the switch 26 is turned on and then turned on for a certain period of time T, the operational amplifier 27 is turned on as in the conventional case.
The input voltage Vr is input as an acceleration pulse through the switch 25, and the input voltage V' is inverted by the inverter 28 and input as a deceleration pulse through the switch 26 to produce an output voltage, which is amplified by the power amplifier 29. A circuit consisting of transistors 30, 31 and resistors 32 to 34 causes the track motor 35 to perform forward and reverse rotation in accordance with the output voltage of the power amplifier 29, and the track motor 35 rotates the objective lens to the information recording medium. A track error in which a shift of the objective lens with respect to a track on the information recording medium is detected by jumping from an arbitrary track on the information recording medium to the next track by moving the objective lens in a direction perpendicular to the upper track. A track error signal is obtained from the detection means for each track jump.

The track error signal from this track error detection means is input to level comparators 36 and 37.

The level comparator 36 is composed of two comparators 38 and 39 and a NOR circuit 40 as shown in FIG.
- Compared with Vrefl, the NOR circuit 40 is the comparator 3
By taking the NOR of the output signals of 8 and 39, it is determined whether the one track jump is optimal, large, or small. The output signal ■■ of the comparators 38 and 39 and the output signal ■■ of the NOR circuit 40 are the 10th if the one track jump is optimal.
If the 1-track jump is too large as shown in Figures 10 and 13, the result will be as shown in Figures 10 and 14, and if the 1-track jump is too small, the first
0 and 15. Similarly, the level comparator 36 is composed of two comparators 41 as shown in FIG.
,42. ! l: Consisting of a NOR circuit 43, comparators 41 and 42 respectively convert the track error signal from the track error detection means into a reference voltage +Vref2. −
Compared with Vref2, the NOR circuit 43 is the comparator 4.
Take the NOR of the 1°42 output signal. Output signal of comparator 41゜42 ■'■' and output signal of NOR circuit 43 ■'
When the one-track jump is optimal, when the one-track jump is too large, and when the one-track jump is too small, the results are as shown in FIG. The count controller 44 includes a comparator 38 in the level comparator 35,
A control signal for the up/down counter (4-bit binary counter) 45 as shown in FIG. 10 is created by one of the output signals 39 and the output signal 2 of the NOR circuit 40. In other words, one track jump is optimal. When the jump of one track is too large, an up count signal is generated, and when the jump of one track is too small, a down count signal is generated. The up/down counter 45 is a count controller 44
The up/down count is performed by the control signal from.

In addition, the counter I-controller 46 performs up/down counter control in the same way as the recurrent controller 44 by using one of the output signals ■'■' of the comparators 41 and 42 in the level comparator 36 and the output signal ■'' of the NOR circuit wI43. The purpose of using the level comparator 36 and count controller 46 is to prevent the up/down counter from erroneously counting, i.e., even though the one track jump is inappropriate as shown in FIG. Since there is a possibility that the level comparator 35 determines that a one track jump is optimal, the level comparator 36 observes the track error signal at the half track jump time, and the output signal of the level comparator 36 is A corresponding control signal from the count controller 46 causes the microcomputer 47 to prevent the up/down counter 45 from erroneously counting.

As shown in FIG. 5, the microcomputer 47 repeatedly performs the one-track jump a specified number of times, and then reads the count value of the up/down counter 45. If the distribution of one track jump is optimal, it will be as shown in Figure 19, and if it is too large, it will be as shown in Figure 19.
If it is too small, it will become as shown in FIG. 21. When the one track jump is optimal, the count value of the up/down counter 45 is a predetermined value, for example, within ±4, as shown in FIG.
If the one-track jump is too large, it becomes larger than ±4 as shown in FIG. 17, and if the one-track jump is too small, it becomes smaller than ±4 as shown in FIG. 18. Therefore, the microcomputer 47 determines whether the one-track jump (acceleration) is optimal, large, or small by determining whether the count value of the up/down counter 45 is within ±4, larger than ±4, or smaller than ±4. , when the one-track jump is large, the constant voltage Vr is lowered by lowering the reference pulse frequency of the reference pulse generator 21 or the pulse width of the mono-multivibrator 22 to reduce the acceleration of the one-track jump, and the one-track jump is reduced. If it is smaller, the constant voltage Vr is increased by increasing the reference pulse frequency of the reference pulse generator 21 or the pulse width of the mono-multivibrator 22, thereby increasing the acceleration of one track jump.

The microcomputer 47 repeats the above operations until it determines that the one track jump is optimal.
In other words, if the one-track jump is not optimal, the process returns to the step of executing the one-track jump a plurality of times.

FIG. 3 shows another embodiment of the present invention, and FIG. 6 shows the processing flow of the microcomputer in this embodiment.

In this embodiment, a microcomputer 47 has the function of the up/down counter 45 in the above embodiment, and the same parts as in FIG. 2 are given the same reference numerals.
4. Performs up/down counting according to the output signal of 46.

FIG. 4 shows another embodiment of the present invention, and FIG. 7 shows the processing flow of the microcomputer in this embodiment.

In this embodiment, a microcomputer 47 has the functions of the count controllers 44 and 46 in the embodiment shown in FIG. 3, and the same parts as in FIG. Level comparator 3
5.36 output signal causes the count controller 44.
46 is performed.

Although the microcomputer 47 controlled the constant voltage Vr in the above embodiment, it may instead control the acceleration/deceleration pulse time T. In other words, if one track jump is optimal, the microcomputer 47 controls the constant voltage Vr. ), the time of the acceleration/deceleration pulse (on time of the switch 25, 26) is set to T, and if the one track jump is too large, the time of the acceleration/deceleration pulse is set to T as shown in FIG. 8(b). If the delay jump is too small, the acceleration/deceleration pulse time may be made longer than T as shown in FIG. 8(c).

(Effects) As described above, according to the present invention, in an optical information recording and reproducing apparatus that uses an optical head to optically record and/or reproduce information on an information recording medium in which tracks are formed in a spiral shape or a concentric shape, Track errors from a driving means for causing the optical head to jump from any track on the information recording medium to an adjacent track, and a track error detecting means for detecting a deviation of the optical head from a track on the information recording medium. Judgment means for comparing the signal with positive and negative constant voltages at the end of the jump to judge whether the jump is good or bad, and adjustment for automatically adjusting the jump acceleration of the driving means according to the judgment result of the judgment means. This eliminates the need for humans to automatically adjust the one-track jump in the optical information recording and reproducing device, and furthermore, it is possible to adjust the one-track jump in the optical information recording and reproducing device on the production line. This eliminates the need for optical information recording and reproducing devices, making them suitable for mass production, eliminating the need for adjustments after replacing the substrates of optical information recording and reproducing devices, and creating compatibility between the substrates of optical information recording and reproducing devices. Cost reduction becomes possible.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the present invention, Figs. 2 to 4 are block diagrams showing each embodiment of the invention, and Figs. 5 to 7 are processing flows of the microcomputer in each embodiment. 8 is a diagram for explaining the present invention, FIG. 9 is a block diagram showing the configuration of the level comparator in the above embodiment, and FIG. 10 is a diagram showing the output signal of the same level comparator and one track jump. , a diagram showing the relationship between up/down counters, FIG. 11 is a block diagram showing the configuration of another level comparator in the above embodiment, and FIG. 12 shows the relationship between the output signal of the same level comparator and one track jump. 13 to 15 are waveform diagrams for explaining the above embodiment, FIGS. 16 to 18 are diagrams showing the relationship between one track jump and up/down counter in the above embodiment, and FIG. 19 21 to 21 are diagrams showing European measurement distribution in a one-track jump state, FIG. 22 is a diagram for explaining the above embodiment, and FIG. 23 is a waveform diagram for explaining a conventional one-track jump drive circuit. FIG. 24 is a block diagram showing the same one track jump drive circuit. 15... Drive means, 16... Judgment means, 17...
adjustment means. ND Muscle 0 END ND Karasu δ Diagram (C) Lua 6 Tsuru 77 Figure 13 Diagram○○O Muscle/77 Diagram

Claims (1)

[Claims] In an optical information recording and reproducing apparatus that uses an optical head to optically record and/or reproduce information on an information recording medium in which tracks are formed in a spiral or concentric form, the optical head is moved to any track on the information recording medium. from 1
A track error signal from a driving means for causing a jump to an adjacent track and a track error detecting means for detecting a deviation of the optical head with respect to a track on the information recording medium is compared with positive and negative constant voltages at the end of the jump. determining means for determining whether the jump is good or bad;
1. An automatic one-track jump adjustment device comprising: an adjustment device that automatically adjusts the jump acceleration of the driving device in accordance with the determination result of the determination device.