JP2002183973A - Data reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data reproducing device capable of satisfying both of read-out of accurate data under a bad condition and reduction of time until an error is displayed under a condition by preferentially reading out the data in the manner of increasing the number of times of retry operation under the bad condition like vibration or high temperature and preferentially reducing the time until the error is displayed under the normal condition. SOLUTION: The data reproducing device is provided with a data reading out means 3 for reading out the data recorded on a disk 1 and an error detecting means 5 for detecting the error of the recording data read out from the data reading out means 3, and constituted so as to read over again the recorded data when the error of the recorded data is detected by the error detecting means 5, and in this device a temperature detecting means 22 is arranged for detecting the ambient temperature so that the number of times of the reading over operation of the recorded data is made variable in accordance with the ambient temperature detected by the temperature detecting means 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data reproducing apparatus, and more particularly to a data reproducing apparatus suitable for use in a CD-ROM drive for car navigation.

[0002]

2. Description of the Related Art A conventional data reproducing apparatus of this type will be described below with reference to FIGS. Here, FIG. 3 is a block diagram showing a conventional data reproducing apparatus, and FIG. 4 is an explanatory diagram for explaining the principle of data reading in the conventional data reproducing apparatus.

In FIG. 3, 1 is a disk on which digital data is recorded in an uneven shape (pit), 2 is a spin motor for rotating the disk 1, and 3 is a digital data recorded on the disk 1. The pickup 4 is based on the read data from the disc 1
An analog signal processing circuit for outputting a spin servo error signal a indicating the number of rotations of the disk 1 and a pick servo error signal b indicating the position of the pickup 3, and digital signal processing 5 for decoding operations such as error detection and correction of digital data Circuit.

6 outputs a signal processing control signal d and a servo control signal e based on the data error signal c indicating the error correction result in the digital signal processing circuit 5 so as to perform the read operation (retry) of the recording data again. CPU to do, 7
Is a servo circuit for controlling the rotation speed (spindle) of the spin motor 2 and the horizontal position (tracking) and vertical position (focus) of the pickup 3 based on a servo control signal e from the CPU 6.

Reference numeral 8 denotes a data output circuit for outputting reproduced data decoded by the digital signal processing circuit 5, and 9 denotes a disk 1 when the data error signal c returns even if the number of retry operations exceeds a predetermined number of times. An error signal output circuit that outputs an error signal based on an error detection signal f output from the CPU 6 by determining that there is no scratch or dirt on the
Is a data processing circuit that processes the reproduced data from the data output circuit 8 and informs the user of the abnormality of the disk 1 based on the error signal from the error signal output circuit 9 to urge the user to change the disk 1 or remove the stain. It is.

In the above configuration, the servo circuit 7
The number of rotations of the spin motor 2 is controlled (spindle servo control) based on the spin servo error signal a from the analog signal processing circuit 4, and the position of the pickup 3 is controlled (tracking servo) based on the pick servo error signal b. Control, focus servo control). These servo operations (which part of the disk 1 is to be read) can be performed by the
And is controlled by the servo control signal e.

The operation of the digital signal processing circuit 5 is started after the servo circuit 7 is stabilized.
The instruction to start the decoding operation of the digital signal processing circuit 5 is also performed by the CPU 6. That is, CP
When U6 receives the signal g indicating that the servo has been completed from the servo circuit 7, it instructs the digital signal processing circuit 5 to start decoding. Thereafter, when the CPU 6 receives the data error signal c, it outputs a servo control signal e to control the spin motor 2 and the pickup 3, and then outputs a signal processing control signal d to instruct a retry operation.

Next, the principle of reading out digital data recorded on the disk 1 by the pickup 3 will be described with reference to FIG.

The beam emitted from the laser diode 11 is collimated by a collimator lens 12, passes through a beam splitter 13, is condensed by an objective lens 14, and irradiates the disk 1. If a pit exists at this irradiation position, the reflected light will not return to the objective lens 14.
On the other hand, when there is no pit, the reflected light returns to the objective lens 14 and enters the beam splitter 13.

The reflected light whose direction has been changed by the beam splitter 13 is focused by a focusing lens 15 and then applied to a photodiode 16 for detecting the presence or absence of a beam.
As a result, digital data recorded on the disk 1 can be detected, and read data can be output to the analog signal processing circuit 4 and the digital signal processing circuit 5 at the next stage.

[0011]

In the above-mentioned conventional data reproducing apparatus, when the disk 1 is subjected to external vibration, the disk 1 is tilted like the disk 1a shown in FIG.
A shift may occur in the directions indicated by 1b and 1c. Due to such inclination and displacement of the disk 1, reflected light is generated by the photodiode 16 even though there is no pit.
However, there is a problem that the recording data cannot be read accurately.

By the way, since an erroneous detection occurs due to this vibration for a moment, there is a high possibility that accurate recording data can be read out by repeating the retry operation many times. However, if the number of times the retry operation is repeated is set to be large, there is a problem that the waiting time until an error is displayed becomes long even when the disc 1 has a scratch or dirt in a normal state.

When the ambient temperature increases, the luminous efficiency of the laser diode 11 decreases. However, when the luminous efficiency decreases beyond a threshold level that can be determined by the photodiode 16, the recorded data can be read accurately. There was a problem that it could not be put out.

Since the threshold level of the photodiode 16 has a certain width, it is highly possible that accurate recording data can be read out by repeating the retry operation many times within the width.
However, if the number of times the retry operation is repeated is set to be large, there is a problem that the waiting time until an error is displayed becomes long even when the disc 1 has a scratch or dirt in a normal state.

The present invention has been made in view of such a point, and under bad conditions of vibration or high temperature, the number of retry operations is increased to give priority to data reading, and in normal times, an error display until error display is performed. It is an object of the present invention to provide a data reproducing apparatus that can satisfy both of accurate data reading under bad conditions and time reduction until an error display in a normal state by giving priority to time reduction.

[0016]

According to the present invention, there is provided a data reproducing apparatus comprising: a data reading means for reading data recorded on a disk; and an error detecting means for detecting an error in recorded data read from the data reading means. A data reproducing apparatus for re-reading (retrying) the recorded data when an error of the recorded data is detected by the error detecting means, wherein a temperature detecting means for detecting an ambient temperature is provided; Depending on the ambient temperature detected by the means,
The number of times of the read operation of the recording data is made variable.

In the data reproducing apparatus of the present invention, the number of retry operations is made variable by grasping the temperature which adversely affects the reading of the recorded data and the number of retry operations is variable. By giving priority to data reading and shortening the time to error display in normal times, both accurate reading of data under bad conditions and shortening of time to error display in normal times can be realized simultaneously. Can be.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a data reproducing apparatus according to the present invention will be described below with reference to FIGS. 1 and 2. The same reference numerals are used for the same parts as those in the conventional example, and the description is omitted. . Here, FIG. 1 is a block diagram showing the data reproducing apparatus of this embodiment, and FIG. 2 is a flowchart showing the processing operation of the CPU 6 in the data reproducing apparatus of this embodiment.

As shown in FIG. 1, the data reproducing apparatus of this embodiment has a vibration sensor 21 for detecting an external vibration level, in addition to the configuration of the conventional data reproducing apparatus described above.
A temperature sensor 22 for detecting an ambient temperature is provided.

In a state where there are many large vibrations or a high temperature, recorded data read from the disk 1 has many errors. Therefore, when a large vibration is detected by the vibration sensor 21 or when a high temperature is detected by the temperature sensor 22, the CPU 6 increases the number of times of rereading (retrying) the recording data as compared with the normal time,
The recording data is decoded as much as possible and can be output to the data output circuit 8.

In the above configuration, the vibration sensor 21
The acceleration sensor used for self-contained navigation in navigation may be used, and the temperature sensor 2
2 may use a simple thermistor. In any case, any device may be used as long as it converts the magnitude of vibration and the level of temperature into an electric signal.

Next, the processing operation of the CPU 6 in the data reproducing apparatus of this embodiment will be described in more detail with reference to the flowchart of FIG.

First, the user operates the CPU 6 by operating a key.
Of the disk 1 to be read (STEP 1). At this time, the retry counter inside the CPU 6 is set to 0 (STEP 2). Then, the CPU 6 outputs a servo control signal e to the servo circuit 7 based on a command by a key input, and the servo circuit 7 servos the spindle motor 2 and the pickup 3 (STEP 3).

Further, the servo circuit 7 determines whether further servo control is necessary based on the error signals a and b from the analog signal processing circuit 4 indicating the quality of the disk reproduction state, and further control is required. In this case, the operation of STEP 3 is repeated (STEP 4). Then, 1 is added to the retry counter inside the CPU 6 (STEP 5). When the CPU 6 receives a signal g indicating that the servo is completed (stable) from the servo circuit 7, the CPU 6 instructs the digital signal processing circuit 5 to decode the currently read data (STE).
P6).

Next, the CPU 6 determines whether or not the external vibration is large based on the detection signal g from the vibration sensor 21 (STEP 7). If it is determined that the vibration is large, the number of retry operations is set to 5 (step 7). (STEP 9) If the vibration is determined to be small, the number of retry operations is set to one (STEP 10). Further, it is determined whether or not the external temperature is high based on the detection signal h from the temperature sensor 22 (ST
EP8) If the temperature is determined to be high, the number of retry operations is set to 5 (STEP 9); if the temperature is determined to be low, the number of retry operations is set to 1 (STEP 9).
10).

Then, it is determined whether there is a data error signal c from the digital signal processing circuit 5 (STEP 11). If there is no data error signal c, an instruction is issued to output the data to the data output circuit 8 as it is (STEP 1).
2). On the other hand, when the data error signal c is present, it is determined whether the number of retry operations has reached the set specified number of times (STEP 13). Is reached, it is determined that the disc 1 is scratched or dirty, and an error detection signal f is output to the error signal output circuit 9 (STEP 1).
4).

Thus, in the data reproducing apparatus according to the present embodiment, the number of retry operations is set to five and the data reading is prioritized under bad conditions of vibration and high temperature, and the number of retry operations is normally set to 1 under normal conditions. By setting the number of times to prioritize the reduction of the time until the error display, it is possible to satisfy both the accurate data reading under bad conditions and the reduction of the time until the error display in normal times.

In the above embodiment, the case where the number of retry operations under bad conditions is set to 5 has been described. However, the number of retry operations is not limited to this, and retry is performed in multiple stages following changes in vibration level and temperature. Obviously, the number of operations may be changed.

Further, the data reproducing apparatus of the present invention
The effect is more remarkable when used for navigation used in a vehicle that has a lot of vibration and is likely to increase in temperature.

[0030]

According to the data reproducing apparatus of the present invention, the number of retry operations is made variable by grasping the temperature which adversely affects the reading of recorded data and the number of retry operations is variable. Priority is given to data readout and to reduction of time to error display in normal times, thereby realizing both accurate data readout under adverse conditions and reduction of time to error display in normality at the same time. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a data reproducing apparatus of the present invention.

FIG. 2 shows C in an embodiment of the data reproducing apparatus of the present invention.
It is a flowchart which shows the processing operation of PU6.

FIG. 3 is a block diagram showing a conventional data reproducing apparatus.

FIG. 4 is an explanatory diagram for explaining the principle of data reading in a conventional data reproducing device.

[Explanation of symbols]

 Reference Signs List 1 disk 2 spindle motor 3 pickup 4 analog signal processing circuit 5 digital signal processing circuit 6 CPU 7 servo circuit 8 data output circuit 9 error signal output circuit 10 data processing circuit 21 vibration sensor 22 temperature sensor

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G11B 20/18 572 G11B 20/18 572F

Claims (1)

[Claims] 1. A data reading means for reading data recorded on a disk, an error detecting means for detecting an error in the recording data read from the data reading means, and an error in the recording data detected by the error detecting means. In the data reproducing apparatus, when detected, a read operation of the recorded data is performed again, wherein a temperature detecting means for detecting an ambient temperature is provided, and the recording data is read in accordance with the ambient temperature detected by the temperature detecting means. A data reproducing apparatus characterized in that the number of times of re-reading is variable.