JPH05290499A - Information reproducing device - Google Patents

Abstract

PURPOSE:To identify a chucking condition between an information recording medium and a turntable by counting a pulse from a pulse generation means for a specified period of time at the initial time of acceleration when a spindle motor is started to be rotated. CONSTITUTION:When a counted output does not surpass a reference pulse number Np within a specified period of time, a time calculation is operated again by a timer 14 with a timer output zero after the passage of the specified period of time, the result is outputted to a counter 13 as a timer output, an index pulse 9 is counted by the counter 13, reference pulse numbers Np are compared by a comparator 15 and an operation for identifying whether the counted output surpasses the reference pulse number Np or not is repeated during the time for measuring. When the counted output does not surpass the reference pulse number Np during the period of repeating the identification operation to the time when the measuring is over, a normal chucking is identified by a controller 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reproducing apparatus for detecting a chucking error of an information recording medium with respect to a turntable.

[0002]

2. Description of the Related Art Conventionally, in an information reproducing apparatus for reproducing a disc-shaped information recording medium such as an optical disc, when the information recording medium is inserted, the hub portion is not properly fitted to the turntable, that is, a chucking error occurs. When,
The information recording medium does not rotate but only the turntable rotates, and the recording surface or the hub portion of the information recording medium is scraped, which may damage the information recording medium.

A means for detecting such a chucking error is proposed in, for example, Japanese Patent Laid-Open No. 2-64962. In this Japanese Patent Laid-Open No. 2-64962, the inclination of the surface of the chucked information recording medium in the track tangential direction is detected by using at least two tilt sensors, and it is determined that any inclination exceeds a predetermined value. An apparatus is disclosed which detects a chucking error by making a determination by a section.

On the other hand, as disclosed in Japanese Unexamined Patent Publication No. 1-298572, a spindle motor for rotating an information recording medium and a frequency generator fixed to the rotary shaft of the spindle motor are provided, and the spindle motor is kept at a constant speed. By counting the output pulse of the frequency generator during acceleration, it is possible to determine the type or presence of the information recording medium, or
A device for determining the type or presence of the information recording medium by measuring the rotation speed of the spindle motor when the output of the frequency generator reaches a predetermined pulse number has been proposed. Although it is possible to determine the types or presence / absence of a plurality of information recording media, it is not possible to detect a chucking error of the information recording media.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the conventional chucking error detecting device disclosed in Japanese Patent Publication No. 962, when the warp of the disc 100 as an information recording medium is large, the chucking state of the disc 100 is as shown in FIG.
In this case, the tilt sensors 101a and 101a
At the position where b is arranged, the detected disc 10
Since the inclination of 0 becomes large due to the warp, there is a problem that an incorrect determination is made as a chucking error.

Further, as shown in FIG. 16, for example, in the magneto-optical disk 103 protected by the cartridge 102, the position where the tilt sensors 104a and 104b are arranged is limited by the shutter window portion 105 of the cartridge 102. For this reason, the tilt sensor 1
The tilt sensor relative angle 106 between 04a and 104b cannot be obtained so much, the tilt directions detected by the tilt sensors 104a and 104b are substantially the same, and a chucking error may be erroneously detected.

Further, the conventional chucking error detecting device requires at least two tilt sensors, which causes a problem that the information reproducing device becomes large.

Furthermore, since the conventional chucking error detecting device detects the inclination of the information recording medium, it can detect only the chucking error and cannot detect the slip of the information recording medium. In addition, another device must be used to detect the slip, which causes a problem that the scale of the entire device becomes large and the cost increases.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an information reproducing apparatus capable of accurately and easily detecting a chucking error.

[0010]

In the information reproducing apparatus of the present invention, a turntable on which a disc-shaped information recording medium is mounted, a spindle motor for rotating the turntable, and a drive control for the spindle motor are provided. Acceleration at the start of rotation of the spindle motor, comprising drive control means and pulse generation means provided facing the rotation shaft of the spindle motor and generating at least one pulse each time the rotation shaft makes one rotation. At the initial stage, the chucking state of the information recording medium and the turntable is determined by counting the pulses from the pulse generating means for a predetermined time.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 relate to a first embodiment of the present invention, and FIG. 1 is a configuration diagram showing a configuration of a main part of an information reproducing apparatus,
FIG. 2 is an explanatory view for explaining changes in the number of rotations of the rotary shaft of the spindle motor, and FIG. 3 is a timing chart for explaining the operation of the main part of the information reproducing apparatus.

As shown in FIG. 1, the information reproducing apparatus 1 includes, for example, a turntable 5 on which a hub portion 4 of an optical disk 3 protected by a cartridge 2 is fitted to mount the optical disk 3, and a rotary shaft 7. Is fixed to the center of the turntable 5, a spindle motor 6 that drives the turntable 5 to rotate, a spindle motor drive circuit 8 that drives and controls the spindle motor 6, and a rotary shaft 7 of the spindle motor 6 An index pulse generator 10 that generates one or several index pulses 9 every rotation, a discriminator 11 that discriminates the chucking state of the optical disk 3 based on a signal from the index pulse generator 10, and the spindle motor drive circuit 8 And a controller 12 for controlling the discriminator 11.

The discriminator 11 includes a counter 13 for counting the index pulse 9 from the index pulse generator 10, a timer 14 for resetting the counter 13 at a predetermined time interval, and a counter 14 within the predetermined time by the timer 14. The comparator 12 is composed of a comparator 15 for comparing the index pulse number which is the output of 13 and a predetermined reference pulse number Np, and the controller 12 judges the chuck state by the output of the comparator 15.

In the initial rotation state in which the spindle motor 6 is rotated from the stopped state to a certain rotation number by the spindle motor drive circuit 8, the index pulse number N output by the time t is the drive torque T, the rotation axis 7 and the turn. Assuming that the moment of inertia of the table 5 is Jm, the moment of inertia of the mounted optical disk 3 is Jd, the number of index pulses generated in one rotation is n, and the proportional constant is K, then N = K · n · T · t ² / {2 (Jm + Jd)} (1), which is controlled by the servo system by the controller 12 so that the rotation speed becomes constant when the predetermined rotation speed is reached from the initial rotation state.

FIG. 2 shows a change in the number of rotations of the rotary shaft 7 of the spindle motor 6. The one-dotted broken line indicates when the optical disk is normally mounted on the turntable 5, and
The broken line is for the turntable 5 only. When a chucking error occurs, a curve as shown by the solid line in FIG. 2, that is, in the initial stage of rotation, the rotational drive is hindered by the static friction between the hub portion 4 of the optical disk 3 and the turntable 5, and the static friction changes to the dynamic friction. After the transition, the rise is almost the same as in the case of only the turntable 5 shown by the broken line. The initial rotation state of the rotary shaft 7 of the spindle motor 6 is
There is a difference between the case where a chucking error occurs and the case where the optical disk is properly mounted on the turntable 5.

As shown in FIG. 2, the above-mentioned predetermined reference pulse number Np is a pulse number according to a predetermined number of revolutions at which the hub portion 4 of the optical disk 3 is not damaged when a chucking error occurs, and A period until the optical disc is properly mounted, for example, 90% of the predetermined number of rotations is set as a chucking error measurement period, and the timer 1 is set in this measurement period.
The determination of the chucking state for a predetermined time according to 4 is repeated once or a plurality of times, and the measurement is stopped when the chucking error is determined. It should be noted that the chucking error measurement period is a period until it reaches, for example, 90% of the predetermined number of rotations when the optical disc is normally mounted, but the present invention is not limited to this, and the above-mentioned case when the optical disc 3 is normally mounted is used. It may be a period up to a predetermined rotation speed.

The operation of the chuck state determination of the information reproducing apparatus 1 thus configured will be described.

As shown in FIG. 3, the controller 12 is
A spindle signal is output to the spindle motor drive circuit 8 to drive the spindle motor 6 to rotate, and the timer 14 is reset. The timer 14 outputs a timer output, which is a time integration signal, to the counter 13, and after the predetermined time has elapsed, sets the timer output to 0 and integrates the time again, and outputs the time output to the counter 13. The counter 13 counts the index pulse 9 from the index pulse generator 10 until the timer output, which is a time integration signal, reaches a value corresponding to a predetermined time. The comparator 15 compares the count output, which is the integrated signal of the index pulse number from the counter 13, with the reference pulse number Np, and indicates whether the count output exceeds the reference pulse number Np, for example, H when the count output is exceeded. If the level is not exceeded, an L level signal is output to the controller 12 as a discriminator signal.

As shown in FIG. 3 (b), the controller 12 outputs the reference pulse number N by the discriminator signal.
When it exceeds p, the timer 13 is reset and it is determined that a chucking error has occurred. In addition, FIG.
If the count output does not exceed the reference pulse number Np within a predetermined time as shown in FIG.
After the predetermined time has elapsed, the timer output is set to 0 and time integration is performed again, and the result is output to the counter 13 as a timer output. The counter 13 counts the index pulse 9, the comparator 15 compares the reference pulse number Np, and the count output is The operation for determining whether or not the reference pulse number Np is exceeded is shown in FIG.
Repeat for the measurement period shown in. When the count output does not exceed the reference pulse number Np over the repeated determination until the measurement period ends, the controller 12 determines that the chucking is normally performed.

Therefore, the information reproducing apparatus 1 of the first embodiment
Determines the chuck state based on the number of rotations of the rotary shaft 7 of the spindle motor 6 repeatedly until the measurement period ends, so that the influence of the warp of the information recording medium and the influence of the cartridge as a protection member of the information recording medium are influenced. It is possible to accurately and easily detect a chucking error without receiving the error.

Next, the second embodiment will be described.

4 to 9 relate to the second embodiment, FIG. 4 is a block diagram showing a configuration of a main part of the information reproducing apparatus, FIG. 5 is a flow chart showing a control flow of the microcomputer, and FIG. 6 is a microcomputer. 7 is a flow chart showing the flow of a modified example of the control of FIG. 7, FIG. 7 is a timing chart for explaining the operation of the modified example of the control of the microcomputer of the main part of the information reproducing apparatus, and FIG. 8 is the rotary shaft of the spindle motor when slip occurs 9 is a flow chart showing the flow of control of the microcomputer in the case where slippage has occurred.

As shown in FIG. 4, the information reproducing apparatus 21 of the second embodiment is almost the same as the information reproducing apparatus 1 of the first embodiment, that is, the discriminator 11 and the controller 12 in the first embodiment are used. It is configured by a microcomputer (hereinafter referred to as a microcomputer) 22. Since the other configurations are the same as those in the first embodiment, the same reference numerals are given to the same configurations and the description thereof will be omitted.

The operation of the chuck state determination of the information reproducing apparatus 21 having the above-mentioned microcomputer 22 will be described.
The measurement period and the reference pulse number Np are set as in the first embodiment (see FIG. 2). Further, during this measurement period, the determination of the chuck state for a predetermined time by the internal timer in the microcomputer 22 is repeated once or plural times.

The microcomputer 22 determines the chuck state according to the flowchart shown in FIG. That is,
Starting from step (hereinafter referred to as S) 1, the spindle motor 6 is driven from the stopped state by the spindle motor drive circuit 8 and the internal timer in the microcomputer 22 is started at S2.

In S3, the presence or absence of the input of the index pulse from the index pulse generator 10 corresponding to the number of rotations of the rotary shaft 7 of the spindle motor 6 is determined. If the index pulse is input, the process proceeds to S4, and if not input, the S5 is performed. Proceed to.

The index pulse is counted by the internal counter in S4, and it is determined in S5 whether or not the counted index pulse number exceeds the reference pulse number Np. If it exceeds, the process proceeds to S6, and it is determined that the chucking error is in S6. Then, the process proceeds to S11 to end the process. If the counted index pulse number does not exceed the reference pulse number Np, the process proceeds to S7.

In S7, it is determined whether or not the internal timer in the microcomputer 22 has passed the predetermined time. If not, the process returns to S3, and the internal timer in the microcomputer 22 goes from S3 to S3 until the predetermined time has passed. The process of S7 is repeated.
When the internal timer in the microcomputer 22 has passed the predetermined time, the process proceeds to S8.

In S8, the internal timer and the internal counter are reset, and the process proceeds to S9. In S9, it is determined whether or not the number of resets exceeds a predetermined number of resets corresponding to the measurement period. If not, the process returns to S2, The processes of S2 to S9 are repeated until the number of resets exceeds the predetermined number of resets corresponding to the measurement period. If the number of resets exceeds the predetermined number of resets corresponding to the measurement period, S10
Proceed to step S10 and determine that there is no chucking mistake in step S11.
Then, the process ends.

As described above, the information reproducing apparatus 21 of the second embodiment.
Is the discriminator 11 and the controller 12 in the first embodiment.
Since it is configured by the microcomputer 22, the size can be reduced in addition to the effect of the first embodiment.

Although the control flow of the microcomputer 22 is according to the flow chart shown in FIG. 5, the flow is not limited to this, and other flow charts such as the flow chart shown in FIG. 6 may be used. That is, as shown in FIG. 6, the microcomputer 22 starts from S12, drives the spindle motor 6 from the stopped state by the spindle motor drive circuit 8 and confirms the first index pulse in S13. When the index pulse is confirmed, S14
The internal timer is reset with and the internal timer is started with S15. Then, in S16, the input of the next index pulse is waited for, and when the index pulse is input,
In S17, the time interval between index pulses is measured by the internal timer, and it is determined whether or not this time interval is within a predetermined time interval. Here, the predetermined time interval is the time interval of the index pulse at the predetermined rotation speed shown in FIG. If this time interval is within a predetermined time interval (see FIG.
(B)) The process proceeds to S19, the chucking error is determined at S19, and the process ends at S21. If this time interval exceeds the predetermined time interval (FIG. 7 (a)), S
Proceed to 18.

In S18, the number of index pulses input by the internal counter is counted, and it is determined whether the count value exceeds a predetermined number. Here, the predetermined number is, for example, the number of index pulses until the rotation shaft 7 reaches a predetermined rotation number when the optical disk is normally mounted on the turntable 5. If the count value exceeds the predetermined number, the process returns to S14 and the processes of S14 to S18 are repeated. If the count value exceeds the predetermined number, S20
Proceed to step S20 and determine that there is no chucking error in step S21.
Then, the process ends.

The control of the microcomputer 22 is performed as follows when the optical disc 3 is mounted on the turntable 5 when it slips.

That is, when the chucking error occurs and the slippage occurs between the optical disk and the turntable 5, the change in the rotational speed of the rotary shaft 7 of the spindle motor 6 becomes as shown in FIG. The solid line indicates that the optical disk 3 is normally mounted on the turntable 5 and no slippage has occurred, and the dashed-dotted line indicates the turntable 5
In the case of only, the two-dot broken line indicates the case where a chucking error occurs, and the broken line indicates the case where only a slip occurs.

When a chucking error occurs, as shown by the two-dot broken line, the rotational drive is hindered by the static friction of the hub portion 4 of the optical disk 3 and the turntable 5 at the initial stage of rotation, and the static friction is changed to the dynamic friction. After that, the rise is almost the same as in the case of only the turntable 5 indicated by the dashed line. If only slippage occurs, no slippage occurs at the beginning of rotation of the rotary shaft 7 of the spindle motor 6, so it is the same as in the case where the slippage occurs normally. It becomes inertia, and the rotation of the rotary shaft 7 of the spindle motor 6 becomes faster.
Therefore, the initial rotation state of the rotary shaft 7 of the spindle motor 6 is different between when a chucking error occurs, when only slippage occurs, and when the optical disk is properly mounted on the turntable 5.

A chucking error measurement period is defined as a period up to 90% of a predetermined number of rotations when the optical disk is properly mounted, and the chucking state is discriminated once or a plurality of times during this measurement period. The measurement is stopped when it is determined that there is a chucking error or slip. It should be noted that the chucking error measurement period is a period until it reaches, for example, 90% of the predetermined number of revolutions when the optical disc is properly mounted, but it is not limited to this, and the predetermined period when the optical disc is normally mounted is set. It may be a period up to the number of rotations.

As described above, the control in the case where the optical disc 3 is slipped on the turntable 5 when mounted is as shown in FIG.
Follow the flowchart shown in. Start from S50,
In S51, the internal timer of the microcomputer 22 is reset.
The input of the first index pulse is awaited in S52. When the index pulse is input, the internal timer is started in S53, and the input of the next index pulse is awaited in S54. When the index pulse is input, S55
Then, the first pulse interval t1 of the index pulse is measured from the value of the internal timer and the value is stored in the internal memory.
Then, in S56, the input of the next index pulse is awaited.
When the index pulse is input, the next pulse interval t2 of the index pulse is calculated from the value of the internal timer in S57.
Is measured and the value is stored in the internal memory. S58 to S5
The first pulse interval t1 and the next pulse interval t stored in 5
2 and the pulse interval ratio t1 / t2 is obtained. Since this pulse interval ratio t1 / t2 is equal to the ratio of the number of revolutions, it is determined whether a rapid increase in the number of revolutions occurs by comparing the pulse interval ratio t1 / t2 with a predetermined number. Judge by making a comparison. If the pulse interval ratio t1 / t2 exceeds the predetermined number, the process proceeds to S61, it is determined that a chucking error or slip has occurred, and the process proceeds to S62 to end the process. When the pulse interval ratio t1 / t2 is within the predetermined number, the process proceeds to S59, and it is determined whether the rotation speed has reached the predetermined rotation speed in FIG.
Returning to 6, waiting for the input of the next index pulse, when the index pulse is input, the pulse interval t3 next to the index pulse is measured from the value of the internal timer in S57 and the value is stored in the internal memory. In S58, the control is repeated to obtain the pulse interval ratio t2 / t3 between the previous pulse interval t2 and the current pulse interval t3 and compare it with a predetermined number. When the rotation speed reaches the predetermined rotation speed in FIG. 8,
In step S60, it is determined that there is no chucking error or slippage, and the process ends in step S62.

By controlling in this way, in addition to the effect of the first embodiment, the slip state of the medium can be easily determined. In addition, in FIG. 9, the pulse interval of the index pulse is measured for each pulse, but not limited to this,
It is also possible to measure the intervals of several pulses.

Next, a third embodiment will be described.

10 to 14 relate to the third embodiment, and FIG. 10 is a configuration diagram showing the configuration of the main part of the information reproducing apparatus,
FIG. 11 is an explanatory diagram for explaining the index pulse generator,
FIG. 12 is a flow chart showing a control flow of the microcomputer, FIG. 14 is an explanatory diagram explaining an index pulse from the index pulse generator, and FIG. 14 is a flow chart showing a flow of a modification of the control of the microcomputer.

The information reproducing apparatus of the third embodiment is almost the same as the information reproducing apparatus of the second embodiment, except that the index pulse unit 33 of the information reproducing apparatus 31 is an optical disc as shown in FIG. By detecting one or a plurality of index marks (hereinafter referred to as IDX marks) provided on the concentric circles, which are provided in opposition to the recording surface of the optical disc 3 and have different reflectances, which are pre-recorded on the optical disc 3. The point is that the index pulse 9 is generated and the microcomputer 22 determines the chucking state using the index pulse 9.

Since the other construction is the same as that of the second embodiment, the same constructions are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 11A, the index pulse device 33 includes a shutter opening portion other than the movable range 35 of the optical pickup for reading information on the optical disc 3 protected by the cartridge 2 having the shutter opening portion 2a. It is provided at a position 33a within the opening range of 2a, and
As shown in (b), the LED 36 that irradiates the measuring light onto the IDX marks 37 having different reflectances recorded in advance on the optical disc 3 and the PD (photodiode) that detects the light from the LED 36 reflected by the optical disc 3 ) 38 and. The index pulse generator 33 may be installed at, for example, the position 33b, that is, the shutter opening 2a other than the movable range 35.
Within the opening range of.

The operation of the chuck state determination of the information reproducing apparatus 31 thus configured will be described.

The microcomputer 22 determines the chuck state according to the flowchart shown in FIG. That is, starting from S22, the spindle motor 6 is driven from the stopped state by the spindle motor drive circuit 8 and the internal timer in the microcomputer 22 is started in S23. The index pulse from the index pulse generator 33 at this time, when a chucking error occurs, the turntable 5 idles, and the drive torque T for rotationally driving the optical disk 3 becomes extremely small. As described in the first embodiment. From the equation (1), the index pulse number N decreases as shown in FIG. 13B when the chucking error does not occur (FIG. 13A). Therefore, unlike the first embodiment, the reference pulse number Np 'is a pulse number corresponding to a predetermined rotation number of the optical disc in which the hub portion 4 of the optical disc 3 is not damaged, and the above-mentioned reference when the optical disc is normally mounted. The period before the time up to the predetermined number of revolutions is the chucking error measurement period.

At S24, the IDX mark 37 on the optical disk 3
By detecting the presence or absence of the input of the index pulse 9 generated by the index pulse generator 33,
If it is input, the process proceeds to S25, and if it is not input, S26.
Proceed to.

In S25, the index pulse is counted by the internal counter, and in S26, it is judged whether or not the internal timer has passed the predetermined time.
The process returns to step S24 to S26, and if the internal timer has passed the predetermined time, the process proceeds to step S27.

In S27, it is determined whether or not the counted index pulse number is within the reference pulse number Np, and if it is within the reference pulse number Np ', the process proceeds to S28. In S28, it is determined to be a chucking error and the process proceeds to S32. finish. When the counted index pulse number exceeds the reference pulse number Np ', the process proceeds to S29.

In S29, the internal timer and the internal counter are reset, the process proceeds to S30, and it is determined in S30 whether the number of resets exceeds a predetermined number of resets corresponding to the measurement period. If not, the process returns to S23, The processes of S23 to S30 are repeated until the number of resets exceeds the predetermined number of resets corresponding to the measurement period. When the number of resets exceeds the predetermined number of resets corresponding to the measurement period, the process proceeds to S31, it is determined that there is no chucking error in S10, and the process ends in S32.

Therefore, similar to the second embodiment, in addition to the effect of the first embodiment, the size can be reduced and the rotation speed of the optical disk is directly measured, so that the chuck state can be determined more accurately.

The index pulse 9 is generated by the index pulse generator 33 detecting the IDX marks with different reflectances recorded on the optical disc 3 in advance, but the invention is not limited to this.
The index pulse 9 may be generated by detecting the sector mark indicating the beginning of the sector as an index mark by setting the optical pickup for reading the information on the optical disc 3 in the defocused state.

The control flow of the microcomputer 22 is shown in FIG.
However, the present invention is not limited to this, and other flowcharts, for example, the flowchart shown in FIG. 14 may be followed. That is, the microcomputer 22
14 starts from S33, and then S3, as shown in FIG.
4. Spindle motor 6 to spindle motor drive circuit 8
Is driven from the stopped state, the internal timer is reset, and the internal timer is started in S35. Then wait for the input of the first index pulse in S36,
The internal timer measures the time during which the index pulse is not input. If this time exceeds the predetermined time and overflows, the process proceeds to S40, and if the index pulse is input and does not overflow, the process proceeds to S37. S
At 37, the input of the next index pulse is waited, and at S38, the time when the index pulse is not input is measured by the internal timer. If this time exceeds the predetermined time and overflows, the process proceeds to S40 and the index pulse is input. If no overflow occurs, the process proceeds to S39.

In step S39, the number of index pulses input by the internal counter is counted, and it is determined whether or not the count value exceeds a predetermined number. Here, the predetermined number is, for example, the number of index pulses until the optical disc 3 reaches a predetermined rotation number when the optical disc is normally mounted on the turntable 5. When the count value exceeds the predetermined number, the process returns to S34 and the processes of S34 to S39 are repeated. If the count value exceeds the specified number, S
41, and in S41, it is determined that there is no chucking error and S
Then, the process proceeds to 42 to end the process. In S40, it is determined that a chucking error has occurred, and the process proceeds to S42 to end the processing.

The chucking errors may be detected by combining the above embodiments.

Further, in each of the above embodiments, the information recording medium is an optical disc, but the present invention is not limited to this, and it may be, for example, a magneto-optical disc, that is, the information reproducing apparatus uses a disc-shaped information recording medium as a turntable. Any device that can be detachably mounted may be used.

[0057]

As described above, according to the present invention, the information reproducing apparatus of the present invention counts the pulses from the pulse generating means for a predetermined time at the initial acceleration stage when the spindle motor starts rotating. Since the chuck state between the recording medium and the turntable is determined, it is possible to accurately and easily detect the chucking error.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a main part of an information reproducing apparatus according to a first embodiment.

FIG. 2 is an explanatory diagram illustrating changes in the number of rotations of the rotation shaft of the spindle motor according to the first embodiment.

FIG. 3 is a timing chart illustrating an operation of a main part of the information reproducing apparatus according to the first embodiment.

FIG. 4 is a configuration diagram showing a configuration of a main part of an information reproducing apparatus according to a second embodiment.

FIG. 5 is a flowchart showing a control flow of the microcomputer according to the second embodiment.

FIG. 6 is a flowchart showing a flow of a modified example of control of the microcomputer according to the second embodiment.

FIG. 7 is a timing chart for explaining the operation of a modification of the control of the microcomputer of the main part of the information reproducing apparatus in the second embodiment.

FIG. 8 is an explanatory diagram illustrating a change in the number of rotations of the rotation shaft of the spindle motor when a slip occurs according to the second embodiment.

FIG. 9 is a flowchart showing a control flow of a microcomputer when a slip occurs according to the second embodiment.

FIG. 10 is a configuration diagram showing a configuration of a main part of an information reproducing apparatus according to a third embodiment.

FIG. 11 is an explanatory diagram illustrating an installation position of the index pulse generator according to the third embodiment.

FIG. 12 is a flowchart showing a control flow of the microcomputer according to the third embodiment.

FIG. 13 is an explanatory diagram illustrating index pulses from the index pulse generator according to the third embodiment.

FIG. 14 is a flowchart showing a flow of a modified example of control of the microcomputer according to the third embodiment.

FIG. 15 is an explanatory diagram illustrating a chucking state of a disc with large warpage in the information reproducing apparatus according to the conventional example.

FIG. 16 is an explanatory diagram illustrating a chucking state of a cartridge type disc of an information reproducing apparatus according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Information reproducing apparatus 3 ... Optical disk 4 ... Hub section 5 ... Turntable 6 ... Spindle motor 7 ... Rotation shaft 10 ... Index pulse generator 11 ... Discriminator

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[Procedure amendment]

[Submission date] November 6, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

On the other hand, as disclosed in Japanese Unexamined Patent Publication No. 1-298572, a spindle motor for rotating an information recording medium and a frequency generator fixed to the rotary shaft of the spindle motor are provided, and the spindle motor is kept at a constant speed. By counting the output pulse of the frequency generator during acceleration, it is possible to determine the type or presence of the information recording medium, or
By measuring the rotational speed of the spindle motor when the output of the frequency generator has become the number of pulses in a predetermined, apparatus for determining the type or presence of the information recording medium it has been proposed
However , such an apparatus can determine the type or presence / absence of a plurality of information recording media, but cannot detect a chucking error of the information recording media.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

Further, as shown in FIG. 16, for example, in the magneto-optical disk 103 protected by the cartridge 102, the position where the tilt sensors 104a and 104b are arranged is limited by the shutter window portion 105 of the cartridge 102. For this reason, the tilt sensor 1
There is a problem that the tilt sensor relative angle 106 between 04a and 104b cannot be obtained so much that the tilt directions detected by the tilt sensors 104a and 104b are substantially the same direction, and an erroneous determination is made unless it is a chucking error .

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction content]

In S18, the number of index pulses input by the internal counter is counted, and it is determined whether the count value exceeds a predetermined number. Here, the predetermined number is, for example, the number of index pulses until the rotation shaft 7 reaches a predetermined rotation number when the optical disk is normally mounted on the turntable 5. Count value exceeds a predetermined number
If not , the process returns to S14 and the processes of S14 to S18 are repeated. If the count value exceeds the predetermined number, S2
It advances to 0 and it is judged that there is no chucking mistake in S20 and S2.
The process proceeds to 1 and ends the process.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

The microcomputer 22 is controlled as follows.
The optical disc 3 and turntable 5
Detects that either King Miss Slip has occurred
be able to.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction content]

That is, when a chucking mistake occurs
In case of slippage between the optical disk and the turntable 5, the change in the number of rotations of the rotary shaft 7 of the spindle motor 6 becomes as shown in FIG. 8, where the solid line indicates the optical disk on the turntable 5. No. 3 is normally attached and no slip occurs, the one-dot broken line indicates only the turntable 5, the two-dot broken line indicates a chucking error, and the broken line indicates only slip.

[Procedure Amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction content]

The control in this case follows the flowchart shown in FIG. Starting from S50, the internal timer of the microcomputer 22 is reset at S51. The input of the first index pulse is awaited in S52. When the index pulse is input, the internal timer is started in S53,
The input of the next index pulse is awaited in S54. When the index pulse is input, the first pulse interval t1 of the index pulse is measured from the value of the internal timer in S55 and the value is stored in the internal memory. Then, in S56, the input of the next index pulse is awaited. When the index pulse is input, the pulse interval t2 next to the index pulse is measured from the value of the internal timer in S57 and the value is stored in the internal memory. In S58, the pulse interval ratio t1 / t2 between the first pulse interval t1 and the next pulse interval t2 stored in S55 is obtained. Since this pulse interval ratio t1 / t2 is equal to the ratio of revolutions, the rapid increase of revolutions Whether or not it has occurred is determined by comparing the pulse interval ratio t1 / t2 with a predetermined number. If the pulse interval ratio t1 / t2 exceeds the predetermined number, the process proceeds to S61, it is determined that a chucking error or slip has occurred, and the process proceeds to S62 to end the process. If the pulse interval ratio t1 / t2 is within a predetermined number, S5
9, it is determined whether or not the rotation speed has reached the predetermined rotation speed in FIG. 8. If not, the flow returns to S56, waits for the input of the next index pulse, and when the index pulse is input, S57 Then, the pulse interval t3 next to the index pulse is measured from the value of the internal timer and the value is stored in the internal memory. In S58, the control is repeated to obtain the pulse interval ratio t2 / t3 between the previous pulse interval t2 and the current pulse interval t3 and compare it with a predetermined number. When the number of rotations reaches the predetermined number of rotations shown in FIG. 8, the process proceeds to S60, it is determined that there is no chucking error or slip, and the process ends at S62.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction content]

By controlling in this way, in addition to the effect of the first embodiment, the slip state of the medium can be easily determined. In addition, in FIG. 9, the pulse interval of the index pulse is measured for each pulse, but not limited to this,
You may measure the interval for every several pulses.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0053

[Correction method] Change

[Correction content]

The control flow of the microcomputer 22 is shown in FIG.
However, the present invention is not limited to this, and other flowcharts, for example, the flowchart shown in FIG. 14 may be followed. That is, the microcomputer 22
14 starts from S33, and then S3, as shown in FIG.
4. Spindle motor 6 to spindle motor drive circuit 8
Is driven from the stopped state, the internal timer is reset, and the internal timer is started in S35. Subsequently, the time when the index pulse is not input is measured in S36 to S37 . If this time exceeds the predetermined time and overflows, the process proceeds to S40 and overflows.
If not , the process proceeds to S37. Waiting for the input of the next index pulse in S37, if the index pulse is input
If so , the process proceeds to S39.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0054

[Correction method] Change

[Correction content]

In step S39, the number of index pulses input by the internal counter is counted, and it is determined whether or not the count value exceeds a predetermined number. Here, the predetermined number is, for example, the number of index pulses until the optical disc 3 reaches a predetermined rotation number when the optical disc is normally mounted on the turntable 5. If the count value does not exceed the predetermined number, the process returns to S34 and the processes of S34 to S39 are repeated. When the count value exceeds the predetermined number, the process proceeds to S41, it is determined that there is no chucking mistake in S41, and the process ends in S42. In S40, it is determined that a chucking error has occurred, and the process proceeds to S42 to end the processing.

[Procedure Amendment 10]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 11

[Correction method] Change

[Correction content]

FIG. 11

[Procedure Amendment 11]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 14

[Correction method] Change

[Correction content]

FIG. 14

Claims (3)

[Claims] 1. A turntable on which a disc-shaped information recording medium is mounted, a spindle motor for rotationally driving the turntable, drive control means for driving and controlling the spindle motor, and a rotary shaft of the spindle motor. And a pulse generator that generates at least one pulse each time the rotary shaft makes one rotation, and counts the pulse from the pulse generator for a predetermined time at the beginning of acceleration at the start of rotation of the spindle motor. By doing so, the chucking state between the information recording medium and the turntable is determined, and the information reproducing apparatus is characterized. 2. A turntable on which a disc-shaped information recording medium is mounted, a spindle motor for rotationally driving the turntable, drive control means for driving and controlling the spindle motor, and information recorded on the information recording medium. A pulse generating means for detecting a mark and generating at least one pulse each time the information recording medium makes one rotation, and a predetermined pulse from the pulse generating means at the initial stage of acceleration at the start of rotation of the spindle motor. An information reproducing apparatus, wherein a chucking state of the information recording medium and the turntable is judged by counting time. 3. The chuck state between the information recording medium and the turntable is determined by measuring a pulse interval from the pulse generating means at the initial acceleration stage when the spindle motor starts rotating. The information reproducing apparatus according to claim 1 or 2.