JPH0782718B2 - Information read recovery method in disc player - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reading / restoring method in a disc player, and more particularly to information reading / restoring when an information reading point of an optical pickup for reading recorded information on an optical disc pops out of an information recording portion of the optical disc. Regarding the method.

BACKGROUND ART In a disc player, for example, a player that reproduces a digital audio disc on which a PCM signal is recorded, when selecting a desired song automatically and quickly, the TOC (Table of Co
The number of tracks up to the specified address is calculated based on the information read from the ntents), and the search operation is performed to move the pickup to the specified address while counting the number of tracks.

In this search operation, particularly when the designated address is near the outermost periphery of the information recording portion of the disc, the information reading point of the pickup may pop out to the mirror surface portion outside the information recording portion due to eccentricity of the disc or disturbance. In that case, since the read information cannot be obtained from the pickup, the spindle servo that drives the disk to rotate at a constant speed runs out of control.

Therefore, conventionally, whether the information recording unit or the mirror surface portion is detected based on the output of the pickup, and when it is detected as the mirror surface portion,
The information reading point of the pickup is returned to the inside of the information recording section by reversing the feed direction of the pickup, and the information reading point is based on the output of the pickup in order to eliminate the influence of the eccentricity of the disc and ensure the information detection. A method has been adopted in which the feeding of the pickup is stopped and a reading operation is started again after a certain period of time elapses from the time when the data enters the information recording unit.

As described above, in the conventional method, since the pickup feed is stopped after a certain time elapses from the time when the information reading point of the pickup enters the information recording portion, the return position is set when the disc is not eccentric. However, there is a drawback that the return position is not constant when there is eccentricity.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and provides an information reading / restoring method in a disc player capable of always keeping the returning position of the information reading point of an optical pickup constant regardless of eccentricity of the disc. The purpose is to do.

The information reading / restoring method according to the present invention detects that the information reading point of the optical pickup has returned to the inside of the information recording section, counts the number of recording tracks that the information reading point crosses from this detection point, and the counted number is It is characterized in that the information reading operation by the optical pickup is restarted again when the predetermined number is reached.

Embodiment Hereinafter, an on-vehicle auto-loading disc player as an embodiment of the present invention will be described with reference to the accompanying drawings.

In the figure, reference numeral 1 indicates the entire auto loading disc player.

As shown in FIG. 1, a front panel 3 forming a part of the housing 2 is provided with a slot 3a for inserting a disc 5 to be played, extending in the left-right direction. However, the left-right direction referred to here is toward the front indicated by the arrow Y. Therefore, the arrow X direction in the drawing indicates the left side, and the arrow Z direction is the upper side. The disk 5 is an optical disk of a type that records and reads a signal using laser light, and has an outer diameter of about 12 cm. The front panel 3 is also provided with an operation button group 6 for operating the disc player, for example, play start and eject. In addition, a schach (not shown) serving as a support member is provided in the housing 2. On this chassis, a disc playing means (not shown) including a turntable, a clamper, a spindle motor, an optical pickup, etc., and a loading mechanism (not shown) for carrying the disc between the slot 3a and the disc playing means. Is placed. The chassis has a housing 2 with four vibration-proof members 8 made of rubber or the like.
Is supported through. However, FIG. 1 shows only the two left vibration isolating members 8.

When playing, a control circuit (not shown) of the playing means executes a sequence as shown in FIG. That is, first, it is determined in step 1 whether or not the pickup is in the home position. If the pickup is in the home position, the pickup is focused (step 2) and the reading operation of the pickup is started. And step 3
At, the information recording start position, that is, the TOC (Table of Contents) position, which is the lead-in area of the disc, is calculated based on the address information obtained by the pickup. The TOC records the number of songs recorded on the disc, the total absolute time, the playing time of each song, etc. It is necessary to read the recorded information of this TOC at the start of the performance. As a method of calculating the TOC position (target address) from the current address, for example, the applicant of the present application, Japanese Patent Application No. 58-201
Using the method proposed in Japanese Patent No. 994 (Japanese Patent Laid-Open No. 60-93685), that is, the closer the target address is, the more accurately the distance to the target address can be obtained. Until then, there is a method of repeatedly calculating the distance to the target and moving the pickup.

When the TOC position is calculated in step 3, the pickup is moved to that position (step 4). Then, the contents of the TOC are read by the pickup (step 5), and then the performance operation is started. The closer the home position of the pickup is to the TOC position, the quicker it is possible to move to the performance operation. When it is determined in step 1 that the pickup is not at the home position, the pickup moving mechanism 216 moves the pickup to the home position (step 6).

If the song to be played is specified, after reading the TOC content, as shown in FIG. 3, the pickup is stepped toward the specified address (address of the specified song) in the initial setting step amount as shown in FIG. To send. Then, in step 8, it is determined whether or not the current address is the designated address. If it is determined that the current address is not the designated address, then in step 9, it is further determined whether or not the current address is larger than the designated address. If the address is larger than the designated address, it is determined in step 10 whether or not the pickup has been sent in the forward (FWD) direction, that is, from the inner circumference to the outer circumference of the disc. If it was sent in the FWD direction, move to step 11 to reverse the feed direction, further reduce the feed step amount (step 12), then feed the pickup by the step amount in step 13, and move to step 8. To do.

If it is determined in step 10 that the data has been sent in the reverse (REV) direction, that is, from the outer circumference of the disc to the outer circumference, it is judged whether the minimum address in the information recording part of the disc is exceeded when sending with the step amount up to that time. If it is judged in step 14 and if it is judged to exceed, the feed step amount is reduced in step 15 and the process returns to step 14 again, and the above operation is repeated until it is judged that the minimum address is not exceeded. Then, when it is determined that the number of times is not exceeded, the process proceeds to step 12.

If it is determined in step 9 that the current address is smaller than the designated address, it is determined in step 16 whether or not the pickup has been sent in the REV direction. If it is determined that the pickup is in the REV direction, the process proceeds to step 11. If it is determined to be in the FWD direction, it is determined in step 17 whether or not the maximum address in the information recording portion of the disc is exceeded when sending by the step amount up to that time, and if it is determined to be exceeded, the step 18 is performed. Then, the feed step amount is reduced to return to step 17, and the above operation is repeated until it is determined that the maximum address is not exceeded. Then, when it is determined that the number of times is not exceeded, the process proceeds to step 12.

The maximum and minimum addresses in the information recording section of the disc are calculated in advance based on the read information of the TOC contents before the search and stored as the maximum and minimum times. In steps 14 and 17, the step amount up to that point is converted to time, the converted time is added (or subtracted) to the absolute time of the current address, and the addition (or subtraction) time is the maximum (or minimum) above. ) It is determined whether the maximum (or minimum) address is exceeded by determining whether it is greater than the time.

By using the above search method, the maximum (or minimum)
Even if an address near the address is specified,
The step amount will not be too large and the pickup will not jump out of the information recording portion of the disc. It should be noted that a method of returning when the pickup jumps out of the information recording section for some reason, or the pickup jumps out to the mirror surface section outside the information recording section due to not adopting the search method described above, the flowchart of FIG. It will be described below based on.

Based on the output of the pickup, it is determined whether the beam spot (information reading point) of the pickup has jumped to the mirror surface portion where information is not recorded (that is, the information non-recording portion).
It is judged at 19. If it is determined that the beam has jumped out, the feed direction of the pickup is reversed (step 20), and it is determined in step 21 whether or not the beam spot has returned to the inside of the information recording section. When it is determined that the beam has returned, the number of recording tracks of the disc that the beam spot crosses is counted based on the output of the pickup (step 22), and when it is determined in step 23 that the counted number has reached a predetermined number, the The information reading operation by the pickup is restarted from the time point.

According to the above-mentioned returning method, the beam spot can be surely returned to the inside of the information recording portion even if the disc is eccentric, and the returning position can be always constant.

Although the auto loading disc player is shown as being mounted on a vehicle, it goes without saying that it can be used indoors for home use.

Effects As described above, according to the present invention, it is detected that the information reading point of the pickup has returned from the mirror surface portion to the inside of the information recording portion, and the number of recording tracks that the information reading point crosses is counted from this detection time point. Since the information reading operation by the pickup is restarted from the time when the count number reaches a predetermined number, the return position of the information reading point can be always fixed regardless of the eccentricity of the disc, and the information reading can be performed. Can be reliably performed.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing the entire vehicle-mounted auto loading disc player according to the present invention, and FIGS. 2, 3, and 4 are explanatory views of the operation of a control system shown by the disc player shown in FIG. It is a flowchart figure for. Explanation of symbols of main parts 2 …… Housing 2b …… Lid body 3 …… Front panel 3a …… Slot 5 …… Disk 6 …… Operating button group 6a …… Play start switch 8 …… Vibration isolator

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Fumihiko Yokokawa 4-2610 Hanazono, Tokorozawa, Saitama Pioneer Co., Ltd. Tokorozawa Plant (72) Keiichi Matsumoto 4-2610 Hanazono, Tokorozawa, Saitama Pioneer Co., Ltd. Judgment body for referees in the Tokorozawa factory Judge General Yasunobu Usuda Judge Matsu Akira Matsuda Judge Takahiro Okada (56) References JP-A-55-125541 (JP, A) JP-A-55-64665 (JP, A) 60-159570 (JP, U)

Claims (1)

[Claims] 1. A method for reading and restoring information in a disc player, wherein information recorded on an optical disc is read by an optical pickup, wherein an information reading point of the optical pickup is a mirror surface of the optical disc based on an output obtained from the optical pickup. The optical pickup is moved toward the information recording portion of the optical disc when it is detected that the information reading point of the optical pickup is a mirror surface of the optical disc based on the output obtained from the optical pickup. From the recording unit to the inside of the information recording unit, and from this detection time, the number of recording tracks of the optical disc that the information reading point of the optical pickup crosses by the output of the optical pickup is counted, and the count number is When the number of lights reaches a certain number, it is considered that the recovery is completed and the optical Information reading recovery method in a disc player, wherein the resume information reading operation by the up.