JPH04251483A - Positioning method for home position - Google Patents

Abstract

PURPOSE:To shorten time until reproducing information in the head track of a directory area after an optical card is loaded to an information recording/ reproducing device. CONSTITUTION:After an optical card 11 is loaded into the information recording/reproducing device, it is detected by driving an optical head 21 and the optical card 11 orthogonally to a track 12 that the optical head 21 gets out of the information recording area of the optical card 11 and when the optical head 21 gets out of the information recording area, the optical head 21 is returned to an information recording area direction by inverting the moving direction. When the optical head 21 is returned to the information recording area, the optical head 21 is stopped and the stop position is decided as a home position.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to an information recording and reproducing apparatus that records and/or reproduces information using an optical card, and the present invention relates to an information recording and reproducing apparatus that records and/or reproduces information using an optical card. The present invention relates to a method for determining a relative position, that is, a home position.

0002

[Prior Art] Optical cards have a storage capacity several thousand to ten thousand times larger than magnetic cards, and although information cannot be rewritten like magnetic cards, their storage capacity is 1 to 10,000 times larger. Because it is large at 2MB, it can be used as a bank passbook, etc.
A wide range of applications are being considered, such as portable maps and prepaid cards used for shopping. Also,
Because it cannot be rewritten, it is also being considered for application in applications that do not allow tampering with data, such as personal health care cards.

Various types of such optical cards have been proposed in the past, and the applicant has also proposed one as shown in FIG. 6 in Japanese Patent Application Laid-open No. 37886/1986.

The optical card 11 shown in FIG. 6 is provided with an optical recording section 13 having a plurality of information tracks 12 parallel to each other, and address information corresponding to each information track is stored at both ends of the optical recording section 13. ID sections 14A, 14 recorded with
B is provided. Since the ID sections 14A and 14B are provided at both ends of the optical recording section 13, the addresses of each track can be read from opposite directions. For example, when the optical card 11 is moving from left to right in FIG. 6 in the track direction relative to the optical head (hereinafter referred to as "forward direction"), the data section 15 is between these ID sections 14A and 14B. , the right ID part 14B is read, and when the optical card 11 is moving from right to left in FIG. 6 in the track direction relative to the optical head (hereinafter referred to as "reverse direction"), the left ID part 14B is read. The section 14A is read to recognize track address information corresponding to the track.

The ID sections 14A and 14B are designed to protect the optical card 1 from being affected by scratches or dirt on the card edges.
In order to sufficiently stabilize the relative movement speed between the optical head 1 and the optical head in the track direction, the optical card 11 is provided at a certain distance (for example, about 4 mm) inward from the end of the optical card 11.

Approximately 2,000 information tracks 12 are formed on the optical card 11, and in order to reproduce desired information from among these tracks, or to input information to a desired one of these tracks. In order to record information, there is usually an area for managing information recorded in the data section 15 (hereinafter referred to as "
It is common to have a "directory area"). Therefore, when inserting an optical card into an information recording/reproducing device to record/reproduce information, it is first necessary to move the optical head to the first track of the directory area of the optical card 11 in as short a time as possible.

FIG. 7 is a diagram showing the overall configuration of a conventional information recording/reproducing apparatus that records/reproduces information using the optical card 11 described above.

Data is recorded/reproduced by moving the optical card 11 in the track direction and moving the optical head 21 in a direction perpendicular to the track direction. optical card 1
1 is a conveyor belt 2 stretched between pulleys 22A and 22B
3 is loaded onto a shuttle 24 provided at a predetermined position, and transported back and forth in the track direction by a motor 26. The motor 26 is controlled by a motor servo circuit 25. A rotary encoder 27 is attached to the motor 26 in order to detect the position of the shuttle 24 with respect to the optical head 21. For example, one pulse of the rotary encoder 27 corresponds to a moving distance of 50 μm of the shuttle 24 with respect to the optical head 21. is set to . According to the position information from this rotary encoder 27, the ID
A control command is sent from the controller 28 to the motor servo circuit 25 so that the transport speed of the optical card 11 between the sections 14A and 14B is constant.

The optical head 21 is connected to the optical head drive circuit 1.
7, the motor 18 is driven to drive the optical card 11.
It is configured to move in a direction perpendicular to the extending direction of the track formed on the track. The motor 18 includes a motor 26
Similarly, a rotary encoder 19 is attached to detect the position of the optical head 21 with respect to the optical card 11. It is configured such that one pulse of the rotary encoder 19 corresponds to, for example, a moving distance of 50 μm of the optical head 21 with respect to the optical card 11 in a direction perpendicular to the track.

The optical system provided in the optical head 21 is of the so-called "off-axis method". The light beam emitted from the laser diode 21A is made into a parallel beam by the collimator lens 21B, and then split into three beams by the diffraction grating 21C, which are incident on the objective lens 21D at a position offset from the central axis C. The three beams focused by the objective lens 21D form three minute beam spots on the information recording surface of the optical card 11. Figure 8 shows
These three beam spots and guide track 12A
FIG. These three beams are arranged in a line obliquely with respect to the guide tracks 12A, 12A, and a main beam 90 with a main optical axis is located in the center.
Sub-beams 91 and 92 formed by sub-optical axes are arranged on both sides so as to cover half of the guide track 12A, and the optical card 11 is
is focused on the information recording surface. The reflected beam from the optical card 11 passes through the objective lens 21D again and is reflected by the mirror 2.
After changing the beam direction by 90 degrees at 1E, the imaging lens 2
An image is formed on a photodetector 21G by 1F.

FIG. 9 is an enlarged view of the photodetector 21G. The photodetector 21G includes two divided photodetecting elements 21G-a and 21G- arranged in the center for detecting focus error signals.
b. Photodetectors 21 for detecting tracking error signals arranged on both sides of the photodetecting elements 21G-a and 21G-b.
It is composed of G-c and 21G-d. Among the three reflected beams, the main beam spot 90' which is the reflected light of the central main beam 90 is split into two photodetectors 21G-a and 21G.
-b, and sub-beam spots 91' and 92', which are reflected lights of the sub-beams 91 and 92 on both sides, are formed on photodetectors 21G-c and 21G-d, respectively.

Here, the main beam entering and reflecting on the information recording surface of the optical card 11 and the two-split photodetector 21G-a. 21G
-b is shown in FIG. As shown in FIG. 10, when the main beam 90 is incident on the information recording surface of the optical card 11 in a focused state (X), the two-split photodetector 21G-a,
The difference in output of 21G-b is zero. On the other hand, optical card 1
When the information recording surface of No. 1 is displaced to position Y, the main beam 90
The reflected beam moves toward the photodetector 21G-b, and the output of the photodetector 21G-a becomes smaller than the output of the photodetector 21G-b. Further, when the information recording surface of the optical card 11 is displaced to position Z, the reflected beam of the main beam 90 is reflected by the photodetector 21G-a.
The output of the photodetector 21G-a becomes larger than the output of the photodetector 21G-b. Therefore, this two-split photodetector 2
By calculating the differential between 1G-a and 21G-b,
The direction and amount of displacement of the optical card 11 can be detected. As mentioned above, the optical card 11 and the objective lens 2
When the distance between 1D becomes closer or farther away, the main beam spot 90' on the two-split photodetectors 21G-a and 21G-b is displaced in the direction shown by arrow F in FIG. The two-split photodetectors 21G-a and 21G-b are positioned so that the center position of the reflected main beam spot 90' in the focused state is located on the boundary line between the photodetectors 21G-a and 21G-b. The photodetectors 21G-a and 21
A focus error signal can be obtained by detecting the G-b output difference.

On the other hand, the tracking error signal is obtained from the difference in output between the photodetectors 21G-c and 21G-d. By driving the objective lens 21D so that this output difference is always zero, the main beam 90 is always directed to the information track 12.
It will follow the above.

In FIG. 7, the output of the photodetector 21G is supplied to a demodulation circuit 29, where a read signal is obtained. Further, a focus error signal and a tracking error signal are detected from the output of the photodetector 21G, and these signals are supplied to the focus/track servo circuit 30. The objective lens 21D is driven in the focusing and tracking directions based on the output of the focus/track servo circuit 30, and control is performed so that the incident light always remains in focus on the optical card 11 and follows the information track 12. are doing.

During data reproduction, the controller 2
8 is a laser diode 21 via a laser drive circuit 31.
A is controlled to a low output to output a reading light beam, and the motor servo circuit 25, optical head drive circuit 17, demodulation circuit 29, and focus/track servo circuit 30 are controlled to perform demodulation. The optical head 21 is sought to a desired track in accordance with the track address information demodulated by the circuit 29 to reproduce data. In addition, during data recording, after the optical head 21 seeks the desired track for recording, the output of the laser diode 21A is switched to high output via the laser drive circuit 31, and the recording light beam is directed to the data to be recorded. The data is modulated and output according to the data, and data is recorded on the track.

[0016] In such an information recording/reproducing device,
A home position sensor 20 is provided, and the position of the optical head 21 is determined using this home position sensor 20 when the optical card 11 is installed. FIG. 11 is a diagram showing the relationship between the optical card 11, the optical head 21, and the home position sensor 20, and FIG. 12 is a flowchart of the home position detection operation of the optical head 21 when the optical card 11 is installed in the information recording/reproducing device. show.

When the optical card 11 is installed, the optical head 21
is located outside the left ID section 14A, as shown in FIG. 11, and moves in the direction indicated by arrow F. The controller 28 detects the output of the home position sensor 20 and stops the optical head 21 on the center line of the home position sensor 20. Next, the objective lens 21D is driven in the focusing and tracking directions to control the incident light so that it follows the track of the optical card 11 in a focused state. Next, a control command is sent from the controller 28 to the motor servo circuit 25, the optical card 11 and the optical head 21 are moved relatively in the track direction, and the output signal of the photodetector 21G is demodulated by the demodulation circuit 29. , track address information of the track where the optical head 21 is located is obtained, and the positional relationship between the optical card 11 and the optical head 21 is grasped. The address information reproduced in this way is checked by means such as error detection, and if the track address information cannot be reproduced normally, error processing such as reading the track address information from the ID section 14B on the opposite side is performed. implement. Next, a control command is sent from the controller 28 to the motor servo circuit 25, and the optical card 11 and optical head 2
Stop moving relative to 1. Thereafter, information is recorded/reproduced while waiting for an instruction from a host computer (not shown). In this case, an instruction is generally sent to reproduce a directory area that manages information recorded in the information recording area of the optical card 11.

[0018]

[Problems to be Solved by the Invention] However, in the above-described conventional home position detection processing method for an optical information recording/reproducing apparatus, the position of the optical head 21 when the optical card 11 is installed in the information recording/reproducing apparatus is determined. To,
The home position sensor 20 is required, which has the disadvantage that the number of parts constituting the information recording/reproducing apparatus increases. In addition, home position sensor 2
An error may occur when attaching 0, and the sensitivity of the home position sensor 20 also varies. Therefore, there will be large variations in the track address information reproduced by the home position detection process described above between individual information recording and reproducing apparatuses. For example, if the installation error of the home position sensor 20 is 500 μm between two information recording/reproducing devices,
If the track pitch is 12 μm, there is a possibility that the addresses of the tracks detected by the above-described home position detection process differ by as many as 40 between these information recording and reproducing apparatuses.

When the first track of the directory area is set as the home position, even if the optical head 21 is stopped using the method described above, the optical head is almost never located on the first track of the directory area. It can be said. Therefore, if the track on which the optical head 21 is located, which has been confirmed through the process shown in the flowchart shown in FIG. However, the optical head 21 cannot be moved to the first track of the directory area by 40 track addresses in the direction perpendicular to the direction of track extension, and then the optical head 21 is By moving the head 21 in the track direction relative to the optical card 11, address information of the track where the optical head 21 is located is obtained. Therefore, it takes time to position the optical head to the first track of the directory area after inserting the optical card and to reproduce the information recorded in the directory area.

In this case, furthermore, when the optical head 21 moves in a direction perpendicular to the direction in which the track extends, the rotary encoder 19 is used for positioning, so the resolution of the rotary encoder 19 Positioning accuracy is affected. For example, one pulse of the rotary encoder 19 moves the optical head 21 over a distance of 50
If configured to correspond to μm, the optical card 1
When the track pitch of the tracks formed in No. 1 is 12 μm, an error of about 4 tracks will occur during this positioning. Therefore, there is no guarantee that the optical head 21 can be moved to the first track of the directory area with one seek operation, and if the optical head 21 cannot be moved to the first track of the directory area even with this seek operation, the optical head 21 It will be moved using 21 track jumps. Therefore, depending on the conventional method, it is difficult to move the optical head 21 to the first track of the directory area in a short time after mounting the optical card.

Other examples of optical cards include, for example, Japanese Patent Laid-Open No. 6
There is one described in Publication No. 2-239354. In this case, a home position mark is set on the optical card 11, as shown in FIG.

In such an optical card 11, the optical recording section 1
A home position mark 16 is pre-recorded on the lower left side of 3, and after the optical card 11 is installed in the information recording/reproducing device, the optical head is first moved in the direction of the arrow in FIG. 13 to the position of the home position mark 16. . Since the positional relationship between the home position mark 16 and the directory area is known in advance, the optical head is then moved from the home position mark 16 to the position of the first track of the directory area, and the directory information is sequentially reproduced. .

However, although such a method does not require a home position sensor, it is troublesome in that a home position mark must be set on the optical card 11 in advance. In addition, if the directory area is provided in the center of the optical recording section 13, unless the movement precision of the optical head 21 is very high, the optical head 21 can move from the home position mark position to the position of the first track of the directory area in a short time. 21 cannot be moved.

The present invention has been made in view of these conventional problems, and it is possible to move an optical head to the first track of a directory area in a short time in an information recording/reproducing apparatus using an optical card. The purpose of this invention is to provide a method for locating the home position when an optical card is installed.

[0025]

[Means and operations for solving the problems] In order to solve the above problems, the home position positioning method of the present invention records and/or reproduces information by relatively moving an optical card and an optical head. In the information recording/reproducing device, when setting the home position of the optical head when the optical card is installed, the optical head and the optical card are aligned perpendicularly to the extending direction of tracks formed on the optical card. detecting that the optical head has moved out of the recordable area of the optical card, and when detecting that the optical head has moved out of the recordable area of the optical card, the optical head The moving direction of the optical head is reversed to return the optical head to the recordable area side, and when the optical head returns to the recordable area, the optical head is immediately stopped and the stopped position is positioned as a home position. It is characterized by this.

As described above, in the home position positioning method of the present invention, the optical head and the optical card are moved relative to each other in the direction perpendicular to the direction in which the tracks extend, and the optical head moves the information recording area of the optical card. It detects that the optical head has come off, and at this time, the moving direction of the optical head is reversed and returned to the information recording area side. When the optical head returns to the information recording area, the optical head is stopped, and this stopping position is set as the home position. I am trying to position it as such. Therefore, there is no need for a home position sensor, and
By setting the first track of the directory area to the track where the optical head stops, the home position determined by the method of the present invention is always located near the first track of the directory area. Therefore, the time required to reproduce the directory information after the optical card is inserted into the information recording device can be significantly shortened.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the overall configuration of an information recording/reproducing apparatus that implements the home position positioning method of the present invention. Components that are the same as those of the conventional information recording/reproducing apparatus explained in FIG. 7 are given the same reference numerals, and their explanations will be omitted.

The difference from the conventional information recording and reproducing apparatus shown in FIG. 7 is that the home position sensor 20 is not provided, and instead, a non-recorded area detection circuit 1 and a recorded area detection circuit 2 are provided. be. The non-recording area detection circuit 1 is a circuit that detects that the optical head 21 has moved out of the information recording area of the optical card 11, and the recording area detection circuit 2 is a circuit that detects that the optical head 21 has returned from the non-recording area to the information recording area. This is a circuit that detects

FIG. 2 is a flowchart showing the procedure of the home position positioning process of the present invention, and FIG. 3 is a diagram for explaining the operation of the optical head 21 on the optical card 11 when performing the home position positioning process. be.

Hereinafter, the home position positioning process when the optical card 11 according to the present invention is installed in an information recording/reproducing apparatus will be explained using FIGS. 1, 2, and 3.

When the optical card 11 is installed in the information recording/reproducing apparatus, the optical head 21 has an optical recording section 13 outside the ID section 14A on the left side of the optical card 11, as shown in FIG.
It is located almost in the center of After controlling the objective lens 21D of the optical head 21 in the focus and tracking directions so that the incident light follows the track 12 formed on the optical card 11 in a focused state, the controller 28 then controls the optical head drive circuit. A control command is sent to the optical head 17 to move the optical head 21 upward in a direction perpendicular to the track 21 (X direction in FIG. 3). optical head 2
1 moves outside the optical recording section 13 , the non-recording area detection circuit 1 detects that the optical head 21 has moved out of the recording area, and outputs a non-recording area signal to the controller 28 . Based on this signal, the controller 28 recognizes that the optical head 21 has moved out of the recording area, and activates the optical head drive circuit 1 to stop the movement of the optical head 21.
7 to stop the optical head 21. Next, a control command is sent from the controller 28 to the optical head drive circuit 17 again to move the optical head 21 in the opposite direction, that is, in a direction perpendicular to the track 12 and downward (Y direction in FIG. 3). When the optical head 21 moves to the optical recording section 13, the recording area detection circuit 2 detects
It is detected that the optical head 21 has moved to the optical recording section 13, and a recording area signal is output to the controller 28. Based on this signal, the controller 28 recognizes that the optical head 21 has returned to the recording area, and stops the optical head 21. That is, the optical head 21 is located at point A in FIG.

As will be described in detail later, the stop position A of the optical head 21 is the second information track from the top of the information recording area. Therefore, by providing the second track from the top as the first track of the directory area, the home position of the optical head 21 is always positioned at the first track of the directory area. Next, a control command is sent from the controller 28 to the motor servo circuit 25 to relatively move the optical card 11 and the optical head 21 in the track direction.
The 1G output signal is demodulated by a demodulation circuit 29 to obtain track address information.

The track address information reproduced in this manner is confirmed by means such as error detection. If the track address information cannot be played normally,
Error processing such as reading the ID section 14B on the opposite side is performed. When the track address information is normally reproduced or when error handling is performed, a control command is sent from the controller 28 to the motor servo circuit 25 again.
The relative movement of the optical card 11 and the optical head 21 in the track direction is stopped.

[0034] If the home position positioning process is performed using such a method, the optical head 21 can be located at the first track of the directory area of the optical card 11 when the optical head 21 is at the home position in any information recording/reproducing apparatus. Even if it is not located on the first track of the directory area, it will be located close to the first track, so use track jump to ensure that the optical head 21 is located on the first track of the directory area. can be moved to Therefore, compared to the conventional method, the optical head 21 can be moved to the first track of the directory area in a shorter time.

FIG. 4 is a waveform diagram for explaining the operation of the non-recorded area detection circuit 1. FIG. 4(A) is a waveform diagram of the reproduction signal of the optical head when the optical head 21 moves in the X direction in FIG. 3, and a signal of 1 is generated every time the optical head 21 crosses the guide track 12A. It is configured to FIG. 4(B) is a waveform diagram showing a binarized playback signal obtained by binarizing this playback signal, and FIG. 4(C)
is a waveform diagram showing a non-recording area signal. The non-recording area signal may be generated by using a retriggerable one-shot circuit when the binary reproduction signal pulses are no longer output continuously, or by using a counter to generate the non-recording area signal within a specified time. It is also possible to generate the pulses when the number of binarized reproduction signal pulses exceeds the number of pulses that are not outputted.

FIG. 5 is a waveform diagram for explaining the operation of the recording area detection circuit 2. It can be configured in the same manner as the non-recorded area detection circuit 1 described in FIG. 4. That is, FIG. 5(A) is a waveform diagram of the reproduction signal of the optical head when the optical head 21 moves in the Y direction in FIG.
After the optical head 21 moves to the information recording area, it is configured so that a signal of 1 is generated every time it crosses the guide track 12A. FIG. 5(B) is a waveform diagram showing a binarized playback signal obtained by binarizing this playback signal. Figure 5 (
The recording area signal shown in C) may be generated when a predetermined number or more of binarized reproduction signal pulses are output within a predetermined time.

In this embodiment, the recording area detection circuit 2 is
When the binarized reproduction signal pulse is output twice in succession,
It is configured to generate a recording area signal, and therefore,
The optical head 21 stops on or near the second information track from the top. Therefore, by setting the first track of the directory area as the second information track from the top, the optical head 21 can be moved to the first track of the directory area in a short time.

By configuring the moving speed of the optical head 21 in the Y direction to be slower than the moving speed in the X direction, the time from when a stop instruction is given to the optical head 21 until the optical head 21 actually stops is The distance becomes shorter, and therefore the error between the position when the optical head 21 stops and the first track of the directory area becomes very small, so the probability that the optical head 21 will be located at the first track of the directory area becomes higher. .

Further, the optical head 21 is driven in the Y direction to detect the recording area, and after the optical head 21 is stopped, the track address obtained by reproducing the track information of the track at the stop position is stored in the directory area. If it is the address of the first track of If the data section is also played back when the data is played, the directory information can be played back in a shorter time.

[0040]

[Effects of the Invention] As described above, the home position positioning method according to the present invention does not require a home position sensor for determining the position of the optical head when an optical card is attached, and therefore the information recording and reproducing apparatus is configured. The number of parts can be reduced. Further, even among a plurality of information recording/reproducing apparatuses, there is almost no difference in the track addresses of the home positions located by the home position positioning method according to the present invention. In other words, the home position will be set to a specific track or a track near the specific track, so if you set this specific track as the first track of the directory area, the directory information will be updated when the optical card is installed. Regeneration can be performed in a short time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an example of an information recording/reproducing apparatus for implementing the home position positioning method of the present invention.

FIG. 2 is a flowchart of home position positioning processing of the present invention.

FIG. 3 is a diagram for explaining the movement of the optical head on the optical card when performing the home position positioning process of the present invention.

FIG. 4 is a waveform diagram for explaining the operation of the non-recorded area detection circuit.

FIG. 5 is a waveform diagram for explaining the operation of the recording area detection circuit.

FIG. 6 is a diagram showing the configuration of an optical card.

FIG. 7 is a diagram showing the configuration of an information recording/reproducing device including a conventional home position sensor.

FIG. 8 is a diagram showing the arrangement of light beam spots formed on an information track formed on an optical card.

FIG. 9 is a diagram showing the configuration of a photodetector of the information recording/reproducing device.

FIG. 10 is a diagram for explaining focusing control in the information recording/reproducing apparatus.

11 is a diagram showing the relationship between an optical card, a home position sensor, and an optical head in the conventional information recording/reproducing apparatus shown in FIG. 7. FIG.

FIG. 12 is a flowchart for performing home position detection processing in the conventional information recording/reproducing apparatus shown in FIG. 7;

FIG. 13 is a diagram showing the configuration of a conventional optical card provided with a home position mark.

[Explanation of symbols]

1 Non-recording area detection circuit 2 Recording area detection circuit 11. Optical card 12 Information track 13 Optical recording section 14 ID section 15 Data section 16 Home position mark 17 Optical head drive circuit 18 Motor 19 Rotary encoder 20 Home position sensor 21 Optical head 21D Objective lens 21G Photodetector 25 Motor servo circuit 26 Motor 27 Rotary encoder 28 Controller 29 Demodulation circuit

Claims (1)

[Claims] 1. In an information recording and reproducing apparatus that records and/or reproduces information by relatively moving an optical card and an optical head, a home position of the optical head is set when the optical card is installed. In doing so, the optical head and the optical card are moved relative to each other in a direction perpendicular to the extending direction of tracks formed on the optical card, and the optical head is removed from a recordable area of the optical card. and when it is detected that the optical head has left the recordable area of the optical card, the moving direction of the optical head is reversed to return the optical head to the recordable area side, and the optical head is A method for positioning a home position of an optical card device, comprising: immediately stopping the optical head when the optical head returns to the recordable area, and positioning the stopped position as a home position.