JPH10172156A - Self-adjusting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-adjusting method which can properly adjust gain for each disk at the time of operating a player by measuring the gain for each disk at the time of driving, comparing this measured value with the target range or value of the gain and, based on the results of comparison, and setting the adjusting value which determines the gain. SOLUTION: When the focal point is out of focus, the reflection from the optical lens 1 irradiates light receptors 21, 22 ununiformly, causing a difference in the output from the light receptor 21 and generating an output in an error detection circuit 4. This output causes current to flow in the focusing voice coil 7 after passing a phase compensator 5 and a driver circuit 6, and the driving force of this coil 7 drives the optical lens 1 to adjust its focal point. On the other hand, the output from the error detecting circuit 4 is inputted into a controlling device 8, where the measured value is compared with the target value etc. to output an adjusting value of gain. This adjusting value is outputted to the on-off control sections of SW1 and SW2 of VCA 31 and 32 to be outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a mini disk (M
D) A self-adjustment method of a servo mechanism for accessing a recording area of a recording medium in a player or the like.

[0002]

2. Description of the Related Art A conventional self-adjustment method will be described using an MD player as an example. An MD player or the like has a self-adjusting function for its servo mechanism in order to compensate for variations in disk characteristics and aging of devices. The MD includes a user-recordable disk called a recordable disk and a non-recordable disk called a pre-mastered disk. FIG. 1A shows a pre-mastered disk that cannot be recorded by the user, and information is recorded by mechanical irregularities called pits like a compact disk (CD). FIG.
(B) shows a recordable disc that can be recorded by the user. Information called TOC is recorded in pits inside the disc, and the voice, title, number of recorded songs, and the like recorded by the user are recorded on the outside. The information is recorded in a magnetically recordable area, and two types of recording methods are mixed on one disk. As described above, when a plurality of recording methods are mixed in one recording medium, characteristics such as a light reflection amount often differ depending on the recording area, and it is necessary to adjust the servo mechanism for each recording area. . Also, the characteristics differ depending on the disc even in the area using the same recording method,
It is necessary to adjust the servo mechanism for each disk.

[0003]

As shown in FIG. 2, in an MD player, a laser beam is applied to the surface of the MD as a recording medium through an optical lens, and the reflected light is read to reproduce the recording. The distance d between the optical lens and the surface of the recording medium is always kept constant. For example, if the optical lens itself shakes due to blurring when the disk rotates or vibration is applied from the outside, the servo mechanism operates to keep the distance d between the optical lens and the surface of the medium constant. In this case, if the gain of the servo mechanism is low, the focus error becomes large and the focus is shifted, so that data cannot be read.
On the other hand, if the gain of the servo mechanism is large, the focus error is small, but if the surface of the medium is scratched or dusty, the amount of reflected light suddenly decreases, and the optical lens is deemed out of focus although it is not actually out of focus. It moves and malfunctions. Therefore, it is necessary to set an appropriate gain of the servo mechanism in the MD player or the like.

In a conventional MD player servo mechanism, the servo gain has been adjusted to an appropriate value before shipment. However, when the disk changes, the amount of reflected light changes, which changes the gain of the servo mechanism.
Therefore, an object of the present invention is to provide a self-adjustment method that can adjust the gain to an appropriate value for each disk when operating a player, instead of adjusting the gain of a servo mechanism at the time of shipment. Another object of the present invention is to provide a self-adjustment method capable of appropriately adjusting a gain even when different recording methods are mixed on a disk.

[0005]

According to the present invention, a gain is measured for each disk during driving, the measured value is compared with a target range or a target value of the gain, and the gain is determined based on the comparison result. An object of the present invention is to provide a method for setting a determined adjustment value and for self-adjusting the gain of a servo mechanism of a device for recording and / or reproducing using a disk-shaped medium. According to the present invention, when the measured value does not reach the target range or the target value, the measurement of the gain and the setting of the adjustment value are repeated a predetermined number of times, and these measured values and the set values are stored, and the measurement of the predetermined number of times is performed. An adjustment value that gives a target range or a measured value closest to the target value is set as an adjustment value for the disk.

In the present invention, a measured value closest to the target range or the target value and a set value to which the measured value is given are stored as a temporary optimum value, and after a predetermined number of times, are stored as the temporary optimum value. Is set as the adjustment value of the disc. Further, in the present invention, a measurement value closest to the target range or the target value among the predetermined number of measurement values is given, and an adjustment value having a gain lower than the target range or the target value is set as the adjustment value of the disk. Things.

Further, in the present invention, a measured value closest to the target range or the target value is given, and a measured value and a set value whose gain is lower than the target range or the target value are stored as a temporary optimum value, and the predetermined number of times are determined. Then, the adjustment value stored as the temporary optimum value is set as the adjustment value of the disk.

[0008]

FIG. 3 shows a waveform of an error signal when an interval between a lens and a surface of a recording medium is shifted from a focal length in an MD player or the like. When the servo gain is large, the amplitude of the waveform is high, and a large error voltage is generated even if the inclination is steep and the focus is slightly shifted. On the other hand, when the servo gain is small, the amplitude of the waveform is low, and a large error voltage is not generated even if the slope becomes gentle and the focus shifts.

FIG. 4 shows an outline of a circuit configuration for setting the gain of the servo mechanism to an appropriate value for each disk. In FIG. 4, reference numeral 1 denotes an optical lens, and reference numerals 21 and 22 denote light receiving elements for receiving light reflected from the optical lens 1, which are arranged at the same distance from the optical lens 1. 31 and 32 are voltage controlled amplifiers (VCA), 4 is an error detection circuit,
5 is a phase compensator, 6 is a driver, 7 is a voice coil for focusing, and 8 is a control device such as a microcomputer. VCA3
Reference numeral 1 denotes an OP amplifier OP1, resistors R11 and R12, and a switch SW1. An input terminal to which an output from the light receiving element of OP1 is input and an output terminal are connected by resistors R11 and R12.
The connection point between the resistors R11 and R12 is grounded via SW1. VCA32 is an OP amplifier OP2, resistors R21 and R22,
And the switch SW2, and has the same connection configuration as the VCA 31.

In the configuration shown in FIG. 4, if the light is focused at a certain set gain, the reflected light from the optical lens 1 is evenly applied to these light receiving elements, and the outputs from the light receiving elements are input to the VCAs 31 and 32, respectively. However, since the outputs from the light receiving elements are the same, the outputs of the VCAs 31 and 32 are equal, the output of the error detection circuit 4 becomes 0, and the focus voice coil 7 does not operate.

If the focus is out of focus, the reflected light from the optical lens 1 does not evenly hit the light receiving elements 21 and 22, resulting in a difference in the output from the light receiving elements. Therefore, a difference occurs between the outputs from the VCAs 31 and 32, and the error detection circuit 4 generates an output.
This output causes a current to flow through the phase voice compensator 5 and the driver circuit 6 to the voice coil 7 for focusing, and drives the optical lens 1 by means of the driving force of the coil 7 in order to focus. On the other hand, the output from the error detection circuit 4 is input to the control device 8 as a measured value of the gain. A target range or a target value of gain (hereinafter referred to as a target value or the like) is set in the control device 8, and the measured value is compared with the target value or the like, and the gain is adjusted based on a difference between the measured value and the target value. Output the value. This adjustment value is output to the on / off control unit (not shown) of SW1 and SW2 of the VCAs 31 and 32, and based on the adjustment value, S
The on / off of W1 and SW2 is controlled, and the amplification ratio of VCAs 31 and 32 changes according to the duty ratio. In the process of focusing, the output of the error detection circuit based on the output adjustment value is input to the control device 8 as a measurement value, and is compared with a target value or the like to output an adjustment value. Is repeated until the measured value matches the target value or falls within the range of the target value.

The above is an example of the configuration for self-adjusting the servo gain. Next, the self-adjustment method of the present invention will be described. FIG. 5 is a flowchart showing an embodiment of the self-adjustment method according to the present invention. First, an MD player or the like is activated (S1). A value at which the measured value will become a target value or the like is stored as an initial value. Next, this value is set as an adjustment value (S2), and the output of the error detection circuit 4 in FIG. 4 is measured (S3). Next, it is determined whether the measured value is within a preset target range or the same as the target value (S4). If No, whether a predetermined number of retries (for example, 5) has been completed is determined. A judgment is made (S5).
Here, assuming that the target value is a, the target range A is, for example, a-
α ≦ A ≦ a + α (α is an arbitrary value). At first, since the number of times has not reached the predetermined number, the result is No, and since this time is not a retry, the number of retries is counted as 0 (S6). Then, the adjustment value set in S2 and the measurement value measured in S3 are stored, and based on a comparison result between the measurement value and the target value or the target range, FIG.
The adjustment value output from the control device 8 is output as a new adjustment value (S7), set as a new adjustment value in S2, and the same retry as the above operation is started. If the measured value does not become the same as the target value or a value within the target range and the above operation is repeated a predetermined number of times, it is determined that the retry has been completed the predetermined number of times (Yes) (S5). The measured value and the adjustment value obtained in the predetermined number of retries are stored, and the adjustment value giving the target value or the measurement value closest to the target range is selected and set (S8). And the retry memory in which the measured value is stored (S9), and the setting of the adjustment value is completed (S10). The above operation is controlled by the control device 8.

On the other hand, if the measured value is the same as the target range or the target value in S4 (Yes), the retry memory is cleared (S9), and the setting of the adjustment value ends (S10).
In the above embodiment, the adjustment values and the measured values in the retry are all stored, but may be stored only when the measured values are within a certain range. FIG. 6 is a flowchart illustrating another embodiment of the self-adjustment method according to the present invention. First, an MD player or the like is started (S1). A value at which the measured value is expected to be a target value or the like is stored as an initial value. Next, this value is set as an adjustment value (S2), and the output of the error detection circuit 4 in FIG. 4 is measured (S2).
3). Next, it is determined whether the measured value is within the preset target range or the same value as the target value (S4). If No, the preset predetermined number of retries (for example, 5 times) is completed. Is determined (S5). Where the target value is a
Then, the target range A is, for example, a−α ≦ A ≦ a + α
(Α is an arbitrary value). At first, since the number of times has not reached the predetermined number, the result is No, and since this time is not a retry, the number of retries is counted as 0 (S6). Up to this point, the flow is the same as the flow in FIG. Next, it is determined whether the adjustment value set in S2 has given the measured value closest to the target value or the target range (S7). At first, since there is no comparison target, the adjustment value set in S2 and the result of S3
Is stored as a temporary optimum value, and the adjustment value output from the control device 8 in FIG. 4 is newly adjusted based on the comparison result between the measurement value and the target range or the target value. The value is output as a value (S8), set as a new adjustment value in S2, and the same retry as the above operation is started. If the measured value does not become the same as the target range or the target value, the above operation is repeated, and the measured value measured in S3 closest to the target range or the target value and the adjustment value given the measured value are provisionally determined. It is stored as an optimum value (S8). If there is a value closer to the target, the stored optimal value is replaced. Otherwise, the result is No in S7 and the value is not replaced (in this case, the measured value is compared with the target value, and a new adjustment value is set. ). The above operation is repeated a predetermined number of times, and if the measured value does not reach the target range or the target value, it is determined that the retry has been completed the predetermined number of times (Yes) (S5). Among the measurement values and adjustment values obtained in the predetermined number of retries, the optimum measurement values and adjustment values are stored as the temporary optimum values as described above, and the adjustment values stored as the temporary optimum values are stored. The value is set (S9), and the setting of the adjustment value ends (S10).

On the other hand, if the measured value falls within the target range or the target value in S4 (Yes), the setting of the adjustment value ends (S4).
10). In the case of the above embodiment, the capacity for storing the adjustment value and the measurement value in the retry can be reduced as compared with the embodiment of FIG. FIG. 7 is a flowchart showing yet another embodiment of the self-adjustment method according to the present invention.
First, an MD player or the like is started (S1). The value at which the measured value will become the target value or the like is stored as the initial value,
Next, this is set as an adjustment value (S2), and the output of the error detection circuit 4 of FIG. 4 is measured (S3). Next, it is determined whether the measured value is within the preset target range or the same value as the target value (S4). If No, the preset predetermined number of retries (for example, 5 times) is completed. Is determined (S5). Here, if the target value is a, the target range A
Can be set to, for example, a−α ≦ A ≦ a + α (α is an arbitrary value). At first, the number of retries is 0 because the number has not reached the predetermined number, and the number of retries is 0 because this time is not a retry.
Is counted (S6). Up to this point, the flow is the same as the flow in FIG. Then, the adjustment value set in S2 and the measurement value measured in S3 are stored, and based on a comparison result between the measurement value and the target value or the target range, FIG.
Is output as a new adjustment value (S7), and is set as a new adjustment value in S2.
The same retry as the above operation is started. When the measured value does not become the same as the target value or the value within the target range and the above operation is repeated a predetermined number of times, the retry of the predetermined number of times is completed (Y
es) is determined (S5). The measured value and the adjustment value obtained in the predetermined number of retries are stored, and from these, the adjustment value that gives the target value or the measurement value closest to the target range and whose gain is lower than the target value is selected. (S8), the retry memory is cleared (S8).
9), setting of the adjustment value ends (S10).

On the other hand, if the measured value is the same as the target range or the target value in S4 (Yes), the retry memory is cleared (S9), and the setting of the adjustment value ends (S10).
In the self-adjustment method of the embodiment shown in FIG.
, All adjustment values and measurement values in the retry are stored, but only the optimum values may be stored as in the flow of FIG. In this case, the storage capacity can be reduced.

[0016]

According to the present invention, since the gain of the servo mechanism is self-adjusted for each disk as a medium, the focus of the optical lens can be appropriately adjusted for individual disks having different light reflection characteristics or regions having different recording methods. Matching and the like can be performed, and recording and reproduction can be accurately performed with an MD player.

In the self-adjustment, the adjustment value is changed up to a predetermined number of times until the measured value becomes equal to the target range or the target value. Even when the value does not reach the target value, the adjustment value having the measured value closest to the target range or the target value is adopted, so that the servo mechanism does not operate unstablely. In the embodiment shown in FIG. 7, since the servo gain is shifted to the lower side, the possibility of servo oscillation is reduced and stability is increased.

Further, even if the ambient temperature changes,
Since the gain can be appropriately adjusted, stable driving can be maintained. In the above embodiment, an MD player has been described as an example. However, the present invention is applicable as long as it handles a disc-shaped medium such as a CD other than an MD.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of a recording structure of an MD.

FIG. 2 is a diagram showing a relationship between a recording medium such as an MD player and an optical lens.

FIG. 3 shows a waveform of an error signal when an interval between a lens and a surface of a recording medium is shifted from a focal length in an MD player or the like.

FIG. 4 shows an outline of a circuit configuration for setting a gain of a servo mechanism to an appropriate value for each disk.

FIG. 5 is a flowchart illustrating an embodiment of a self-adjustment method according to the present invention.

FIG. 6 is a flowchart showing another embodiment of the self-adjustment method according to the present invention.

FIG. 7 shows a further embodiment of the self-adjustment method according to the invention in a flow chart.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical lens 21, 22 ... Light receiving element 31, 32 ... Voltage control amplifier (VCA) 4 ... Error detection circuit 5 ... Phase compensator 6 ... Driver 7 ... Focusing voice coil 8 ... Control device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G11B 21/10 G11B 21/10 R

Claims (6)

[Claims] 1. A gain is measured for each disk during driving,
The measured value is compared with a target range or a target value of the gain, and an adjustment value for determining the gain is set based on the comparison result. The gain of the servo mechanism of the apparatus for recording and / or reproducing using a disk-shaped medium is self-adjusted. In the method, when the measured value does not reach the target range or the target value, the measurement of the gain and the setting of the adjustment value are repeated a predetermined number of times, and these measured values and the set values are stored, and among the measured values of the predetermined number of times, A self-adjustment method for setting an adjustment value giving a target range or a measurement value closest to the target value as an adjustment value of the disk. 2. A gain is measured for each disk during driving, and
The measured value is compared with a target range or a target value of the gain, and an adjustment value for determining the gain is set based on the comparison result. The gain of the servo mechanism of the apparatus for recording and / or reproducing using a disk-shaped medium is self-adjusted. In the method, when the measured value does not reach the target range or the target value, the measurement of the gain and the setting of the adjustment value are repeated a predetermined number of times, and the measured value and the set value closest to the target range or the target value are set to the temporary optimum value. The self-adjustment method stores the adjustment value stored as the temporary optimum value as the adjustment value of the disk after a predetermined number of times. 3. A gain is measured for each disk during driving, and
The measured value is compared with a target range or a target value of the gain, and an adjustment value for determining the gain is set based on the comparison result. The gain of the servo mechanism of the apparatus for recording and / or reproducing using a disk-shaped medium is self-adjusted. In the method, when the measured value does not reach the target range or the target value, the measurement of the gain and the setting of the adjustment value are repeated a predetermined number of times, and these measured values and the set values are stored, and among the measured values of the predetermined number of times, Giving the closest measured value to the target range or target value,
And a self-adjustment method for setting an adjustment value whose gain is lower than the target range or the target value as the adjustment value of the disk. 4. A gain is measured for each disk during driving, and
The measured value is compared with a target range or a target value of the gain, and an adjustment value for determining the gain is set based on the comparison result. The gain of the servo mechanism of the apparatus for recording and / or reproducing using a disk-shaped medium is self-adjusted. In the method, when the measured value does not reach the target range or the target value, the measurement of the gain and the setting of the adjustment value are repeated a predetermined number of times, and the measurement closest to the target range or the target value and lower than the target range or the target value is repeated. A self-adjustment method in which a value and a set value are stored as a temporary optimum value, and after a predetermined number of times, the adjustment value stored as the temporary optimum value is set as an adjustment value of the disk. 5. The method according to claim 1, wherein a gain is measured for each recording area of the disk by a different recording method during driving.
The self-adjustment method according to claim 1. 6. The self-control device according to claim 1, wherein when the measured value is within the target range or the target value, an adjustment value given the measured value is set as a set value of the disk. Adjustment method.