JPH0814943B2 - Address search device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an address in a disc reproducing / recording apparatus having concentric or spiral tracks, on which track addresses regularly recorded are recorded. The present invention relates to a search device.

2. Description of the Related Art In high-speed retrieval of information, which is a great advantage of a disc reproducing apparatus, a recording / reproducing head (hereinafter referred to as a head)
One of the keys to the solution is how quickly you can move to the track that should be searched. By the way, in the conventional address searching device, as shown in FIG. 9, the relationship between the position of the recording / reproducing head and the track address on the disk is fixed, and the pitch storing means 14 and the offset storing means 15 are set. Using the track pitch and the track offset, the position calculating means 6 calculates the pickup position corresponding to the search track address from the search address input means 1, and the recording / reproducing head is operated by the high-speed feed controller 9 using a linear motor or the like. Is moved to the calculated position, and after the movement is completed, the tracking control device 12 is driven to move the recording / reproducing head to a desired position, thereby performing an address search (for example, "Naka Naka et al." Random access method of "Electronics Society Kansai Branch Union Conference, 1982 G2-25).

However, in the conventional method as described above, the adjustment error of the relationship between the position information of the head and the head position in the disk radial direction, the eccentricity of the disk, the variation of the disk track pitch, and the address are zero. There is a problem that the accuracy of address search is lowered when the fixed relationship between the position information of the head and the track address on the disk is broken due to the variation in the position of the track on the disk radius, and the restrictions on the specifications of the disk and the player become severe. Had the problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an address search device in which the accuracy of address search does not deteriorate even when such disc and player variations occur.

Means for Solving the Problems In order to solve the conventional problems, the present invention provides a disc having tracks on which address information is regularly recorded in a concentric circle or a spiral, and recording / reproducing using the disc. At least a tracking control means for performing tracking control of the head, a search address output means for outputting an address signal of a track searched by the disk, and a position signal indicating a position of the head in the disk radial direction. A first storage unit that stores two or more;
Second storage means for storing an address signal indicating an address corresponding to the position indicated by the signal position stored in the storage means, the position signal stored in the first storage means, and the second signal corresponding thereto. Of the address signal stored in the storage means of at least two, and a pitch calculation means for calculating the amount of change of the position signal per one address, and the position signal stored in the first storage means, and the corresponding position signal. An offset calculation means for calculating a position signal at a reference point of the address signal from the address signal stored in the second storage means and the output signal of the pitch calculation means; and an output signal of the pitch calculation means and the offset calculation means. Position calculation means for outputting the position signal of the head corresponding to the output signal of the search address output means by the output signal, and a sampling indicator for instructing sampling of the address signal. And position information selection means for selecting the position signal stored in the first storage means and the output signal of the position calculation means according to the output signal from the sampling instruction means, and the output of the position information selection means. A feed control device for feeding the head to a position designated by a signal,
When the position information selecting means selects the position signal stored in the first storage means, the address signal when tracking is performed corresponds to the position signal stored in the first storage means. And an address reading means for storing in the storage means.

Action The present invention calculates the actual pitch and offset by sampling, and further adjusts the timing of tracking drive at the time of sampling and search, that is, the timing of detecting an address signal to a constant rotational phase of the disk, It deals with the deterioration of the search accuracy due to the variation of the players, and has an advantage that a high-speed address search can be realized without the deterioration of the search accuracy.

Example (Example 1) FIG. 1 shows an example of the present invention. In FIG.
In response to an instruction from the sampling instruction means 7, the position information selection means 8 outputs position information (hereinafter referred to as a position signal) and a position calculation means 6 at a point (hereinafter referred to as a sampling point) in the first storage means 2 where sampling is performed. And output to the feed control device 9. The feed control device 9 is
After the head is moved to the position corresponding to the position information indicated by the output from the position information selecting means 8, the feed end signal is output. The timing detector 10 detects the rotation phase of the disk for each rotation and outputs a timing signal. When the tracking control command means 11 detects the feed end signal and the timing signal, it outputs the tracking drive signal while the feed end signal is being output, thereby driving the tracking control device 12 and thereby moving the head to the track. To match. The head may be aligned with the track so that the track address can be read. The address reading means 13 reads the track address according to the tracking drive signal, and reads the track address to the memory address which is the storage area in the second storage means 3 corresponding to the position signal of the first storage means 2 according to the instruction of the sampling instruction means 7. Write the track address (hereinafter referred to as the address signal). The position per address is determined from the position signals of the sample points stored in at least two or more first storage means 2 and the corresponding address signals stored in the second storage means 3 by performing the above operation. When the amount of change in the signal (hereinafter referred to as the pitch) is calculated by the pitch calculating means 4 and the address signal becomes zero from the position signal of the sample point and the corresponding address signal and the output signal based on the result of the pitch calculating means 4. Position signal (hereinafter, referred to as offset) is calculated by the offset calculation means 5. Based on the pitch calculated by the pitch calculation means 4 and the offset calculated by the offset calculation means 5, the position calculation means 6 calculates the position signal of the head corresponding to the search address output from the search address input means 1. The calculated position signal of the search address is
By the position information selecting means 8, the feed control device 9 is driven to move the head, and after the head feeding operation is completed, a timing signal is output from the timing detector 10 to the tracking control command means 11 for tracking. The control device 12 is operated to complete the address search. In this way, the actual pitch and offset are calculated by sampling, and the timing for tracking drive during sampling and search is adjusted to the constant rotation phase of the disc, so that the search accuracy is reduced due to variations between the disc and the player. can do.

(Embodiment 2) FIG. 2 shows an embodiment in which the present invention is further embodied. In FIG. 2, reference numeral 20 denotes a central processing unit (hereinafter referred to as CPU), which interfaces with peripheral devices through an address bus AB, a data bus DB and a control bus CB for reading and writing. An address decoder 40 decodes the content of the address bus AB and generates a device select signal indicating which device is selected as a peripheral device. Reference numeral 50 is a read-only memory (hereinafter referred to as ROM), which stores the control program of the CPU 20, and further uses D ₁ , D as position signals of sample points.
_It includes a first storage means 2 having ₂ . Reference numeral 60 denotes an arbitrary access memory (hereinafter referred to as RAM), which is used as a data memory of the CPU 20 and which has the position signals D ₁ and D of the sample point.
_Second storage means 3 for storing the address signals A ₁ and A ₂ corresponding to ₂
Is included. Reference numeral 30 denotes an oscillation circuit, which gives the CPU 20 a reference clock for program execution. Key 90 and key 100
The sampling instruction means 7 is constituted by the key 90, and the key 100 instructs the sampling operation of the position signal D ₂ of the sample point by the key 100 of the position signal D ₁ of the sample point. Key
When input of 90 or key 100 is detected from input port 80, C
PU20 stores the position signal of the sampling point corresponding to the input in ROM50
It is read from the first storage means 2 inside and is output to the feed control device 9 via the output port 140. Feed control device 9
Is configured by a linear motor so that the signal indicating the value obtained by D / A converting the input position information of the sampling point and the signal indicating the value of the potentiometer 190 indicating the position of the transfer table 180 in the disk radial direction are equal. The transfer table 180 is fed at a high speed, and after the transfer table 180 reaches a predetermined position, a feed end signal is generated. After detecting the feed end signal through the input port 130, the CPU 20 detects the timing signal from the timing generator 10 (described in FIG. 3) that detects the rotational movement of the disk 210 for each rotation. The tracking controller 12 is driven via the
Controls to scan the track of the disk 210, at the same time reads the address signal demodulated by the address demodulator 150, and at the sample points designated by the keys 90 and 100 of the second storage means 3 in the RAM 60. It is stored as the address signal of the sampling point in the memory address corresponding to the position signal. After the address signals A ₁ and A ₂ corresponding to the position signals D ₁ and D ₂ of the sample points thus read are stored in the second storage means 3, C
The PU 20 calculates the amount of change in the position signal per track address (hereinafter referred to as the pitch P) and the value of position information when the track address is zero (hereinafter referred to as the offset F).
The pitch P and the offset F are calculated by the following equations.

P = | D ₁ −D ₂ | / | A ₁ −A ₂ | …… (1) F = D ₁ −A ₁ · P …… (2) D ₁ , D ₂ : Position signal A _{1 of} each sample point : Address signal corresponding to D ₁ A ₂ : Address signal corresponding to D ₂ Key 100 and key group 120 constitute search address input means 1,
When the key 110 is turned on, the CPU 20 causes the search address A indicated by the key group 120 and the pitch P obtained by sampling.
And the offset F, the position information D corresponding to the search address A is calculated by the following equation.

D = A · P + F (3) The calculated position information D is output to the feed control device 9, and tracking control is performed by the timing signal of the timing detector 10 after the movement of the transfer table 180 is completed as in the sampling. The device 12 is driven and the head is aligned with the track.
In this way, the search is performed accurately and at high speed.

In the embodiment, since the track pitch is a high density of 1.6 μm and the resolution per unit of position signal is insufficient, the search is divided into two types, a coarse search and a fine search. Has been adopted. The fine search is realized by performing a track jump by the jump pulse generator 170 by an error amount in the rough search.

FIG. 3 shows an embodiment of the timing detector 10, in which a mark 211 indicating the rotational phase on the disk 210 (see FIG. 4) is detected by a photo sensor composed of an infrared light emitting diode 100 and a photodiode 101. , The transistor 102 amplifies the signal, the comparator 103 converts the detection signal into a digital signal, and outputs the digital signal as a timing signal indicating a rotation phase.

FIG. 4 shows the shape of the disk 210 used in the embodiment, and the inner circumference of the disk 210 has a mark 211 having a rotational phase different in reflectance from the peripheral portion.

The flow chart of the program written in the ROM 50 is as shown in FIGS.

When the program starts, the CPU 20 waits for the input of the key 90 instructing sampling, and when the input is detected,
Turn off tracking control and execute the sampling program (Fig. 5). Next, wait for the key 100 to be input. When the input is detected, the tracking control is turned off again, the sampling program (Fig. 5) is executed, and the pitch calculation program (Fig. 6) and offset calculation program (Fig. 7) are executed in this order. Then, the input of the key 110 for instructing the search is waited, and when the search instruction is detected, the tracking control is turned off and the search program (FIG. 8) is executed.

 Hereinafter, each program will be described in detail.

FIG. 5 shows a sampling program. Step
Steps 201 to 204 show the operation of the position information selecting means 8,
In response to the input from the sampling instruction means 7, the position signal D ₁ or D ₂ of the sampling point is output from the first storage means 2 to the feed control device 9. Steps 205 to 207 are
The operation of the tracking control command means 11 is shown, and the head 160
When the timing signal from the timing detector 10 is detected after confirming the feed end signal indicating that has reached the sampling point, the tracking control device 12 is driven. Thereby, tracking is performed. Step 208-Step 212
Indicates the operation of the address reading means 13, and the address demodulator 150
After confirming that the address has been read, the read address is stored in the memory of the memory address corresponding to the output of the sampling instruction means 7 in the second storage means 3.

FIG. 6 shows a pitch calculation program, which corresponds to the pitch calculation means 4. Steps 213 to 215 calculate the position interval between the sample points, and steps 216 to 218
Calculates the track address difference between sample points. In step 219, the displacement (pitch P) of the position signal per one track address is calculated.

FIG. 7 shows an offset calculation program, which corresponds to the offset calculation means 5. In steps 221-223,
The position signal when the offset is set to zero is calculated, and in steps 224 to 225, the difference between the actual position signal D ₁ and the position signal when the offset is set to zero is calculated to calculate the offset F.

FIG. 8 shows a search program. Steps 227 to 231 show the operation of the position calculation means 6, and the position signal corresponding to the search address designated by the search address input means 1 is
It is calculated from the calculated pitch P and offset F. Step 232 shows the operation of the position information selecting means 8 and outputs the calculation result of the position calculating means 6 when there is no command from the sampling instructing means 7. Step 233 to Step 235
Shows the operation of the tracking control command means 11. head
After confirming the feed end signal indicating that 160 has reached the search position, when the timing signal from the timing detector 10 is detected, the tracking control device 12 is driven and the search is completed.

As described above, according to the present invention, since the track address of the disk actually used and the positional relationship of the recording / reproducing head of the player in the disk radial direction can be obtained by sampling, the track pitch and the disk of the track address can be obtained. It is possible to accurately calculate the position of the search address on the disk radius even for disks having different radial positions. Further, since the drive timing of the tracking control at the time of sampling and at the time of search is always constant with respect to the rotation phase of the disk, it is possible to suppress variations in the pull-in track due to eccentricity of the disk and prevent the search accuracy from decreasing. With these features, the recording / reproducing head can be moved to the search address at high speed and with high precision, and the address search can be performed quickly.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an address search device of the present invention, FIG. 2 is a block diagram of a specific embodiment of the device, and FIG.
FIG. 4 is a circuit diagram of the timing detector of the apparatus, FIG. 4 is a plan view showing the shape of the disk in this embodiment, FIG. 5 is a flow chart of a sampling program, FIG. 6 is a flow chart of pitch calculation, and FIG. FIG. 8 is a flowchart of an offset calculation, FIG. 8 is a flowchart of a search program, and FIG. 9 is a block diagram of a conventional address search device. 2 ... First storage means, 3 ... Second storage means, 4 ...
Pitch calculation means, 5 ... Offset calculation means, 6 ... Position calculation means, 10 ... Timing detection means, 11 ... Tracking control command means, 20 ... Central processing unit (CP
U), 50 ... Read-only memory (ROM), 60 ... Arbitrary access memory (RAM), 160 ... Recording / playback head, 180 ...
Transfer table, 190 ... Potentiometer, 100 ... Infrared light emitting diode, 101 ... Photodiode, 103 ... Comparator.

Claims (1)

[Claims] 1. A disk having a track in which address information is regularly recorded in a concentric or spiral shape, a recording / reproducing head using the disk, and a predetermined rotational phase of the disk is detected. A timing detector that outputs a signal, tracking control means that detects the output signal of the timing detector and starts tracking control of the head at a constant rotation phase of the disk, and an address signal of a track searched by the disk. The search address output means for outputting, the first storage means for storing in advance at least two or more position signals indicating the position of the head in the disk radial direction, and the position signal stored in the first storage means Second storage means for storing an address signal indicating an address corresponding to the position, the position signal stored in the first storage means, and the corresponding front signal Pitch calculation means for calculating the amount of change of the position signal per one address by using at least two or more address signals stored in the second storage means, and the position signal stored in the first storage means Offset calculation means for calculating a position signal at a reference point of the address signal from the corresponding address signal stored in the second storage means and the output signal of the pitch calculation means, and the output signal of the pitch calculation means and the offset calculation. Position calculation means for outputting the position signal of the head corresponding to the output signal of the search address output means, sampling instruction means for instructing sampling of the address signal, and output signal from the sampling instruction means Position information selection means for selecting the position signal stored in the first storage means and the output signal of the position calculation means in accordance with A feed control device for feeding the head to a position designated by an output signal of the position information selecting means, and a tracking control when the position information selecting means selects the position signal stored in the first storage means and performs tracking control. An address retrieval device for storing an address signal in the second storage means corresponding to the position signal stored in the first storage means.