JP4510275B2 - Method for driving record carrier reading mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a driving method of a record carrier reading mechanism that reads information from a disc-shaped record carrier such as a compact disc (CD).
[0002]
[Prior art]
In a CD deck that reads information such as music from a disc-shaped record carrier (hereinafter, taking a CD as an example) and provides it to a user, a record carrier reading mechanism for reading information from the CD is one of the important components. ing. In this case, when the CD deck is one of in-vehicle audio devices, for example, the installation space is limited, so that it is required to downsize the CD deck. Therefore, the above-mentioned record carrier reading mechanism that particularly requires installation space is strongly required to be downsized.
[0003]
In such a situation, for example, as disclosed in Japanese Patent Application Laid-Open No. 2000-48461, a “pickup unit for reproducing information on a record carrier (CD) and a clamp unit for clamping the record carrier (CD) operate in conjunction with each other. Has been proposed. An example of the structure of this record carrier reading mechanism will be described later with reference to the drawings. In brief, this reading mechanism is in addition to the above-described pickup unit (mounted with a laser beam emitting / receiving body) and a clamp unit. In addition, the origin detection unit (origin switch) for detecting that the pickup unit is at the origin position of the reproduction range on the CD and the clamp unit attached to the turntable for rotating the CD can release the clamp of the CD. And a clamp release switch for detecting the presence. The clamp release switch is activated when the pickup section reaches the limit point closest to the center of the CD beyond the origin switch. At this time, the turntable stops rotating, The movable holding claw provided in the clamp part is automatically pulled into the clamp part, and the CD is released from the restrained state to the free state. After that, the stocker can enter / exit, or the user can replace with a new CD.
[0004]
[Problems to be solved by the invention]
As described above, the clamp release switch is provided in the record carrier reading mechanism, and the switch is directly operated by the pickup unit movable along the radial direction of the CD. It will make further progress and will contribute greatly to its miniaturization.
[0005]
However, by introducing the clamp release mechanism, in the unlikely event, there is a possibility that an undesirable situation may occur in which this mechanism is erroneously operated during the reproduction of a CD.
If such an accidental release of the clamp occurs, not only the CD cannot be reproduced, but also the holding of the CD with respect to the clamp portion becomes unstable. There is a problem of falling into a stuck state where operation stops.
[0006]
There are various causes for the occurrence of such a problem, for example, noise is mixed in a drive control LSI for driving and controlling the entire record carrier reading mechanism, and a disturbance based on strong vibration occurs.
Therefore, in view of the above problems, an object of the present invention is to provide a drive method of a record carrier reading mechanism that can prevent a CD from being unclamped by mistake.
[0007]
[Means for Solving the Problems]
FIG. 1 is a diagram schematically showing a record carrier reading mechanism to which the present invention is applied and its periphery. However, the configuration is merely an example, and the present invention is not limited to this.
In this figure, reference numeral 1 is a record carrier (CD) reading mechanism most relevant to the present invention. The mechanism 1 has a swivel arm 7 and is rotatable as a whole around a support shaft 8 (thick arrow A in the figure). The upper left side of the figure shows the state when the CD deck is not in operation, and the right side shows the state when the CD deck is in operation (during playback).
[0008]
The mechanism 1 has a pickup part (PU) 5 and a clamp part 9 as main parts, and further includes the above-described clamp release switch 10 and an origin detection part (origin switch) 11 fixed to the turntable 6 and its vicinity. Also have.
On the swivel arm 7, a pickup unit 5 is slidably held, that is, movably held in the front-rear direction indicated by an arrow B in the figure. When the movement is started, the clamp release switch 10 is turned off → on to complete the clamping operation, and then the origin switch 11 is turned off → on, and the reproduction range on the CD 4 (region R indicated by hatching in the figure). The inner circumference reference position can be confirmed. From here, counting of tracks on CD4 starts.
[0009]
Reference numeral 3 in the figure is a magazine, which is housed in the housing 2 as a whole. In this case, for example, in the case of a six-changer CD deck, the above-described stocker is formed in the magazine 3. However, this point is not directly related to the present invention.
FIG. 2 shows a detailed example of the record carrier reading mechanism 1 shown in FIG. This figure mainly shows the configuration of the components 9, 10 and 11 described above as an example, and is not limited to the configuration of this figure.
[0010]
This figure shows a case where the mechanism 1 is in the state of the upper right side (during operation) of FIG.
When the power is turned on, the pickup unit 5 (illustrated by a transparent body in this figure) has moved to the aforementioned limit point closest to the clamp unit 9. This movement is performed by a feed motor 14 and a transport unit (rail) 15 that is rotationally driven by the feed motor 14.
[0011]
Next, the feed motor 15 rotates forward and advances toward the outer periphery of the CD4, and first, the clamp release switch 10 is turned from OFF to ON. With this turning on, the already-described holding claws 13 of the clamp part 9 automatically protrude from the inside of the clamp part 9 body to the outside, firmly pressing the edge of the inner hole of the CD 4 and fixing the CD 4 to the clamp part 9. The holding claws 13 are arranged at three locations at intervals of 120 ° on the circumference.
[0012]
When the pressing of the CD 4 is completed (clamping completed), the pickup unit 5 is approaching to the vicinity of the next origin switch 11 and further turns the switch 11 from OFF to ON. By this turning on, the pickup unit 5 confirms that the inner circumference reference position described above has been reached.
FIG. 3 is a timing chart showing the operation of the switches 10 and 11.
[0013]
The operations of the clamp release switch 10 and the origin switch 11 described above become more apparent from the timing chart of this drawing.
In the uppermost column of the figure, a partial cross section of the CD 4 is shown in a horizontal arrangement. The left end is the inner peripheral side, and the right end is the outer peripheral side.
First, the pickup unit 5 (indicated by PU) located closest to the clamp unit 9 starts moving to the outer peripheral side and first turns on the clamp release switch 10 (PU is shifted downward with time). ). As a result, the holding claw 13 of the clamp portion 9 protrudes outward, and the edge of the inner hole of the CD 4 is pressed firmly as shown by the dotted line in the figure, and the clamping is completed.
[0014]
PU further advances to the outer peripheral side and turns on the origin switch 11, which is the origin position of the reproduction range R (the track area where the music is actually recorded) on the CD4, that is, the aforementioned inner circumference reference position.
Hereinafter, the main configuration of the present invention will be described.
FIG. 4 is a flowchart showing a basic driving method according to the present invention.
[0015]
The driving method premised on the present invention is that the pickup unit 5 for reproducing information on the record carrier (CD) 4 and the clamp unit 5 for clamping the CD 4 operate in conjunction with each other, and the pickup unit 5 is in the reproduction range on the CD 4. This is a method of driving the record carrier reading mechanism 1 in cooperation with an origin detection unit (origin switch) 11 that detects that the origin is located at R. In such a mechanism 1, if the pickup unit (PU) 5 starts to run away from the reproduction range R of FIG. 3 toward the inner periphery of the CD 4 for some reason, the PU is in a direction opposite to the arrow shown in FIG. Then, the origin switch 11 is exceeded (ON → OFF), and the clamp release switch 10 is also turned ON → OFF. If it does so, the holding nail | claw 13 will be drawn inside the clamp part 9, and CD4 will be in a free state (problem mentioned above).
[0016]
Steps S11 and S12 in FIG. 4 can prevent such a problem from occurring in a very simple procedure. The first point of attention is that the pickup unit 5 that has started the runaway described above during CD playback always passes the origin switch 11 before reaching the clamp release switch 10. It is to discover.
[0017]
The second point of interest according to the present invention is to detect a signal having a waveform other than a signal waveform that can be assumed in advance when the runaway described above is started. It is to try. A detailed description of the second point of focus will be given in the second half of the following [Embodiment of the Invention] section.
The steps based on the first focus point are as follows.
[0018]
Step S11: A step of determining whether or not both the first condition indicating that the record carrier reading mechanism 1 is in a reproducing operation and the second condition indicating that the origin detection unit (origin switch) 11 is operated are satisfied. It is.
Step S12: This step is to move the pickup unit 5 back to the reproduction range R when it is established.
[0019]
The above steps S11 and S12 are the two steps that form the basis of the present invention.
In view of FIG. 3, the pickup unit 5 that has entered the inner circumferential side of the CD 4 during CD playback is turned to the outer circumferential side of the CD 4 with the switch 11 turned on as a trigger. is there. Thereby, it can avoid that the pick-up part 5 act | operates the clamp release switch 10, and the cancellation | release of an incorrect clamp (release | release of the holding nail | claw 13) can be prevented beforehand.
[0020]
In the above step S12, the reason for expressing “move back to the reproduction range R” instead of “changing the direction to the outer periphery side of CD4” as described above is that the switches 10 and 11 must be in the CD4. This is because the switches 10 and 11 may be arranged on the outer peripheral side of the CD 4 instead of being arranged on the inner peripheral side.
[0021]
The above operation can be performed mainly by the drive control LSI 12 of FIG. The LSI 12 is configured as shown in FIG. 1, for example, and is controlled by a microprocessor (MPU) 120. The MPU 120 is normally provided outside the LSI 12, but is shown incorporated in the LSI 12 for convenience in this figure. Usually, the LSI 12 itself is a DSP.
[0022]
The MPU 120 performs drive control processing in conjunction with the memory 128, exchanges signals with the pickup unit 5 through the I / O interface (INF) 129, and gives drive signals to the clamp unit 9, the feed motor 14, and the like. In addition, well-known focus scanning, tracking servo, etc. are executed, and on / off from the switches (10, 11) is monitored. These are shown as functional blocks in the drawing, such as a pickup control function unit 122, a clamp control function unit 123, a focus scan function unit 124, a tracking servo function unit 125, a feed motor control function unit 126, and a switch (10, 11) monitoring function unit. 127. The overall monitoring of these functional units 122 to 127 is controlled by the determination / instruction means 121. The drive control according to the present invention is also performed under the monitoring of the determination / instruction means 121 (the same applies hereinafter).
[0023]
Referring to FIG. 4 again, it is preferable that steps S13 and S14 are executed following steps S11 and S12.
Step S13: When the pickup unit 5 is moved back to the reproduction range R, the reproduction operation of the record carrier reading mechanism 1 is temporarily stopped. In this case, step S13 and step S12 are executed almost simultaneously. When the reproduction operation is stopped, it is easier to quickly move to the next operation.
[0024]
Step S14: When the pickup unit 5 completes the movement to return to the reproduction range R, the reproduction operation is resumed.
In this case, what position may be determined as the completion of the movement to return to the reproduction range may be determined as appropriate. One can be the aforementioned origin position. Alternatively, the track in which the runaway of the pickup unit 5 has occurred can be stored in the memory 128 and determined to return to the track position. Or you may make it return to the starting point of the music to which the said track position belongs.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Various embodiments based on the first focus point described above will be described below. In this case, the configuration shown in FIGS. 1 to 3 is taken as an example.
FIG. 5 is a flow chart showing a first embodiment in the case of driving shown in FIG.
During CD playback, a process for detecting an abnormality that causes the clamp to be released by mistake is performed.
[0026]
Step S21: It is determined whether or not the pickup unit 5 (referred to as PU) has turned on the origin switch (SW) 11. If it is not ON (No), normal reproduction is temporarily being performed, and the abnormality detection process is terminated (END). If it is ON (Yes), the process proceeds to step S22.
Step S22: The tracking servo operation is turned off. This is because if the tracking servo operation is left ON, there is a possibility of causing further out of focus.
[0027]
Step S23: PU origin position search processing is performed. With this process, the PU can be moved toward the outer periphery of the CD 4. This origin position search process is originally possessed by the MPU (120 in FIG. 1) as an original function, and this function is used as it is for the outer peripheral side movement process of the PU. Therefore, it is not necessary to modify the software for the present invention.
[0028]
Step S24: The tracking servo operation is turned on. This is for starting the reproduction operation.
Step S25: This step is executed as necessary. If out of focus occurs, the focus scanning process is started. This is because the focus may be lost when the PU returns to the origin switch 10.
[0029]
Next, a second embodiment will be described.
FIG. 6 is a flowchart showing a second embodiment of the present invention.
The basic idea of the second embodiment is that the first condition shown in FIG. 4 is to detect the defocusing of the pickup unit 5 during the reproducing operation of the record carrier reading mechanism 1.
[0030]
If NG is monitored while defocusing, it can be seen that the reproduction operation is being performed.
Further, when the pickup unit 5 completes the movement to return to the reproduction range R, the reproduction operation of the record carrier reading mechanism 1 is resumed after retrying the focus scan.
An implementation example of such a second embodiment is as shown in FIG.
[0031]
Perform focus state monitoring.
Step S31: It is determined whether or not a focus is lost (focus OK). If not deviated (OK), the monitoring process is terminated (END). If not, the process proceeds to step S32.
Step S32: Same as step S21 (FIG. 5). If Yes, since PU5 has entered the inner circumference side of CD4, the process proceeds to step S33.
[0032]
Step S33: Same as step S23 (FIG. 5). PU5 is sent out toward the outer peripheral side of CD4.
Step S34: The focus scan process is started. The purpose is the same as in step S25 (FIG. 5). As a result, the reproduction operation can be started again.
Next, a third embodiment will be described.
[0033]
FIG. 7 is a flowchart showing a third embodiment of the present invention.
The basic idea of the third embodiment is that the first condition shown in FIG. 4 is to detect the interruption of the tracking error signal in the tracking operation by the pickup unit 5 during the reproducing operation of the record carrier reading mechanism 1.
If the tracking error is monitored and the result is NG, it can be seen that the reproducing operation is being performed.
[0034]
Furthermore, when the pickup unit 5 completes the movement back to the reproduction range R, tracking servo is executed, and the reproduction operation of the record carrier reading mechanism 1 is resumed.
An implementation example of the third embodiment is as shown in FIG.
Execute tracking abnormality detection processing.
Step S41: It is determined whether or not a tracking error (error) signal is interrupted (tracking error). If no tracking error has occurred (No), this detection process is terminated (END). If it has occurred, the process proceeds to step S42.
[0035]
Step S42: Same as step S21 (FIG. 5). If Yes, since PU5 has entered the inner circumference side of CD4, the process proceeds to step S43.
Step S43: Same as step S22 (FIG. 5).
Step S44: Same as step S23 (FIG. 5).
Step S45: Same as step S24 (FIG. 5).
[0036]
Step S46: Same as step S25 (FIG. 5).
Next, a fourth embodiment will be described.
FIG. 8 is a flowchart showing a fourth embodiment of the present invention.
The basic idea of the fourth embodiment is that the first condition shown in FIG. 4 is that the information reading signal (data signal) is interrupted in the information (data) reading operation by the pickup unit 5 during the reproducing operation of the record carrier reading mechanism 1. Is to detect.
[0037]
If the interruption of the data signal is monitored and it is NG, it turns out that the reproducing operation is being performed.
Further, when the pickup unit 5 completes the movement to return to the reproduction range R, tracking servo is executed, and the reproduction operation of the record carrier reading mechanism 1 is resumed.
An implementation example of such a fourth embodiment is as shown in FIG.
[0038]
Execute detection processing for data signal abnormality.
Step S51: It is determined whether or not the data signal is interrupted. If the data signal is not interrupted (No), the detection process is terminated (END). If it has occurred, the process proceeds to step S52.
Whether the data signal is interrupted can be determined, for example, by giving a specific code at regular time intervals when the data signal is input, and when the specific code cannot be detected. it can.
[0039]
The steps after step 52 are exactly the same as the steps after step 42 in FIG.
Step S52 = Step S42
Step S53 = Step S43
Step S54 = Step S44
Step S55 = Step S45
Step S56 = Step S46
The aspect based on the first viewpoint of the present invention has been described above. Next, the aspect based on the second viewpoint of the present invention will be described. As described in the beginning, when the pickup unit 5 starts to run away, a signal having a waveform other than a signal waveform that can be assumed in advance will be applied to the feed motor 14 in FIG. This is to detect this.
[0040]
Examples based on the second point of focus are the fifth and sixth examples.
The basic idea of the fifth embodiment is to monitor the form of the drive signal applied to the feed motor 14, and when it is detected that this form takes a form other than the form assumed in advance, the feed motor 14 is immediately turned on. Thus, even if the pickup unit 5 moves toward the switch 10, this is stopped.
[0041]
FIG. 9 is a diagram showing a waveform example of the drive signal of the feed motor 14.
In this figure, Pf is a waveform at the time of forward rotation of the feed motor 14 (inner peripheral side → outer peripheral side), and Pb is a waveform at the time of reverse rotation (inner peripheral side ← outer peripheral side). When the drive signal from the MPU 120 is assumed in advance, the above waveform is generated.
FIG. 10 is a flowchart showing a fifth embodiment of the present invention.
[0042]
Perform signal abnormality detection processing.
Step S61: It is determined whether or not tracing is in progress. If No, for example, the origin position search is being performed, and the detection process is terminated (END). If Yes, the process proceeds to step S62.
Step S62: It is determined whether or not the drive signal to the feed motor is normal. If normal (Yes), the process is terminated. If abnormal (No), the process proceeds to step S63.
[0043]
Step S63: The feed motor is stopped. As a result, the pickup unit 5 does not reach the operation of the switch 10.
The basic idea of the sixth embodiment of the present invention is to monitor the form of the drive signal applied to the feed motor 14, and when it is detected that this form takes a form other than the form assumed in advance, the pickup unit 5 The track servo operation is reinitialized and the reproduction operation of the record carrier reading mechanism 1 is restarted. Thereby, it is avoided that the pickup unit 5 reaches the switch 10.
[0044]
FIG. 11 is a flowchart showing a sixth embodiment of the present invention.
Perform signal abnormality detection processing.
Step S71: Same as step S61 in FIG.
Step S72: Same as step S72 in FIG.
Step S73: The LSI 12 of FIG. 1 is initialized.
[0045]
Step S74: The CD4 reproduction start process is entered.
[0046]
【The invention's effect】
As described above, according to the present invention, it is possible to reliably prevent the clamp of the CD 4 from being erroneously released due to the abnormal operation of the pickup unit 5 during reproduction by a very simple method.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a record carrier reading mechanism to which the present invention is applied and its surroundings.
FIG. 2 shows a detailed example of the record carrier reading mechanism 1 shown in FIG.
FIG. 3 is a timing chart showing the operation of the switches 10 and 11;
FIG. 4 is a flowchart showing a basic driving method according to the present invention.
FIG. 5 is a flowchart showing a first embodiment in the case of driving shown in FIG. 4;
FIG. 6 is a flowchart showing a second embodiment of the present invention.
FIG. 7 is a flowchart showing a third embodiment of the present invention.
FIG. 8 is a flowchart showing a fourth embodiment of the present invention.
9 is a diagram illustrating a waveform example of a drive signal of the feed motor 14. FIG.
FIG. 10 is a flowchart showing a fifth embodiment of the present invention.
FIG. 11 is a flowchart showing a sixth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Record carrier reading mechanism 4 ... Record carrier (CD)
DESCRIPTION OF SYMBOLS 5 ... Pickup part 6 ... Turntable 7 ... Turning arm 8 ... Spindle 9 ... Clamp part 10 ... Clamp release switch 11 ... Origin detection part (origin switch)
12 ... Drive control LSI
13 ... Holding claw 14 ... Feed motor 15 ... Conveying section 120 ... Microprocessor (MPU)
121: Judgment / instruction means

Claims (10)

A pickup unit for reproducing the information of the record carrier, provided with a clamp portion for detachably clamping the record carrier, origin detection unit in which the pickup unit detects that the origin position of the reproduction range on the record carrier In a method of driving a record carrier reading mechanism cooperating with
When both the first condition indicating that the record carrier reading mechanism is in a reproducing operation and the second condition indicating that the origin detection unit is activated are satisfied, the pickup unit is returned to the reproduction range. A method of driving a record carrier reading mechanism, characterized by being moved.   2. The method of driving a record carrier reading mechanism according to claim 1, wherein when the pickup unit is moved back to the reproduction range, the reproduction operation of the record carrier reading mechanism is temporarily stopped.   3. The method of driving a record carrier reading mechanism according to claim 2, wherein the reproduction operation is resumed when the pickup unit completes the movement back to the reproduction range.   2. The driving method of the record carrier reading mechanism according to claim 1, wherein the first condition is detecting an out-of-focus state of the pickup unit during a reproducing operation of the record carrier reading mechanism.   5. The recording carrier reading mechanism according to claim 4, wherein when the pickup unit completes moving back to the reproduction range, the reproduction operation of the record carrier reading mechanism is resumed after retrying a focus scan. Driving method.   2. The recording carrier reading mechanism according to claim 1, wherein the first condition is that an interruption of a tracking error signal in a tracking operation by the pickup unit is detected during a reproducing operation of the record carrier reading mechanism. Driving method.   7. The drive of a record carrier reading mechanism according to claim 6, wherein when the pickup unit completes moving back to the reproduction range, tracking servo is executed and the reproduction operation of the record carrier reading mechanism is resumed. Method.   2. The record carrier reading mechanism according to claim 1, wherein the first condition is that an interruption of an information reading signal in an information reading operation by the pickup unit is detected during a reproducing operation of the record carrier reading mechanism. Driving method.   7. The drive of a record carrier reading mechanism according to claim 6, wherein when the pickup unit completes moving back to the reproduction range, tracking servo is executed and the reproduction operation of the record carrier reading mechanism is resumed. Method. A pickup unit for reproducing the information of the record carrier, the record carrier to removably provided with a clamp portion for clamping, the record carrier reading mechanism that cooperates with the feed motor for the front and rear the pickup in the radial direction of the record carrier In the driving method of
The form of the drive signal applied to the feed motor is monitored, and when it is detected that the form takes a form other than the form assumed in advance, the track servo operation by the pickup unit is reinitialized, and the record carrier A method for driving a record carrier reading mechanism, wherein the reproducing operation of the reading mechanism is resumed.

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