JPH07105049B2 - Optical information recording / reproducing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for optically recording and reproducing information, and particularly to a method for recording and reproducing optical information suitable for use in a card-shaped optical information recording medium. Regarding

[Prior Art] Conventionally, various types of media, such as a disk, a card, and a tape, are known as a form of a medium for recording information by using light and reading the recorded information.

Recording and reproduction were performed on these media by methods suitable for various shapes. Among them, in the disk-shaped medium, in the state of being rotated at a predetermined rotation speed,
Information is recorded as an optically detectable recording pit train by scanning a preset recording track on the disk with a light beam which is modulated according to the recording information and is focused on a minute spot. At this time, the irradiation position of the light beam is controlled in a direction perpendicular to the scanning direction (auto tracking, hereinafter referred to as AT in order to accurately record information without causing trouble such as intersection of recording pit rows). In addition, it was necessary to perform focus control (autofocus, hereinafter referred to as AF) in order to accurately focus the light beam on the disk. Therefore, in order to obtain a tracking signal and a focusing signal from the recording track, the modulated light beam is set so that writing is not performed on the disk even at the minimum level. Also, when playing back the recorded information,
This is done by scanning the above-described recording pit row with a light beam having a power level that is not written on the disk.

In such a recording / reproducing method, when recording or reproducing is not in operation (excluding when the power of the device is off, the period from the recording operation to the recording operation, or from the reproduction operation to the reproduction operation, etc. In this case), the drive operation of the disk, that is, the rotational drive is not stopped, and the next operation is made to stand by. This is because if the drive operation is stopped after every non-operation, it takes a long time to start up the drive operation each time the operation is performed, which greatly affects the recording / reproducing time.

In addition, the principle of recording and reproducing is the same as that of the disk medium in the card-shaped medium, except that a plurality of linearly arranged tracks on the card are reciprocally moved with respect to the light beam. The point is to record or reproduce.

[Problems to be Solved by the Present Invention] However, in the recording or reproducing method for the card-shaped medium, the recording or reproducing time is shortened as much as possible in the same manner as the recording or reproducing method for the disk-shaped medium when recording is not performed. For this reason, if the drive operation is kept in a standby state without being stopped, there is a problem that the power consumption is increased due to the reciprocating motion.

[Means for Solving the Problem] In view of such a problem, the present invention solves the problem in the above-mentioned conventional method and realizes a card-shaped optical information recording medium which can perform high-speed recording / reproducing and consumes less power. It is to provide an optical recording / reproducing method.

And, the above-mentioned object is an optical information recording / reproducing method of irradiating a light beam to a card-shaped optical information recording medium having a plurality of linear tracks to record or reproduce information. The recording or reproducing operation stage for recording or reproducing by relatively reciprocating the medium and the light beam, and the relative movement of the medium and the light beam along the track are stopped, and the light beam is moved to the medium. Inactive phase at the end of the truck.

[Operation] In the present invention, paying attention to the fact that the velocity always becomes zero at the turning point in the reciprocating motion, and when not operating, the optical dome is made to stand still at that position (track end in the present invention). ing. In other words, this means that only one of the normal reciprocating motions is in operation due to the stationary state at the end of the track. You can return in the shortest time compared to the case of waiting at the position. or,
Since it stands still and stands by, there is an effect that it consumes less power.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a schematic plan view showing an example of an optical card used in the device of the present invention. In the figure, 1 is an optical card, 2 is a recording track formed in a plurality of linear shapes on the optical card, 3 is a data recording area of a recording track in which a light beam is scanned at a predetermined speed, and 4 and 4'are desired. A track selection area 5 in which a track is searched is a home position of a light beam. The light beam is initially stationary at home position 5. At the time of recording or reproducing, the light beam first moves in the track selection area 4 in the a direction to find the Nth track 2 to be recorded or reproduced. Then, the light beam scans the data recording area 3 on the track 2 in the direction of arrow C for recording or reproduction. When the recording or reproduction is completed, the light beam stops in the track selection area 4'and stands by until the next recording or reproduction is performed. When a recording or reproducing command comes, this light beam moves in the direction of arrow a in the selected area 4'to the next track to be recorded or reproduced (for example, the N + 1th track), and after searching for the track, this The track data recording area 3 is scanned in the direction of arrow b, and recording or reproduction is similarly performed. Then, by repeating this operation, a predetermined amount of data is recorded or reproduced.

FIG. 3 is a diagram for explaining the power of the light beam on the optical card during recording and reproduction, (A) during recording and (B) during reproduction, respectively. Further, the horizontal axis of the figure shows the position on the track, and the vertical axis shows the optical power P. At the time of recording, the light beam does not form a recording pit in the scanning range E _W corresponding to the data recording area as shown in (A), and also has the minimum power required to obtain the tracking signal and the focusing signal.
_PWL always illuminates the optical card. Then, according to the recording signal, it is modulated with the power P _WH required for recording, and the recording pit is formed only on the portion irradiated with the power P _WH . Further, during reproduction, the light beam is emitted at a constant power P _R where the recording pits are not formed in the scanning range E _R , and the above-mentioned recording pits are read.

Here, the recording sensitivity S of the normal optical card is determined by the irradiation power P of the light beam and the irradiation time T. Therefore, when the spot of the light beam is scanned from 6'to 6 at a relative velocity V as shown in FIG. 4, if the spot system is φ, V is not recorded if V / φ / T or more. However, as described above, when the light beam is standing by in a stationary state, if this state continues for a long time, erroneous recording will occur even if the optical power is P _WL or P _{R as} described above. In the present invention, the time of such a stationary state is measured and the irradiation of the light beam is stopped before erroneous recording.

FIG. 1 is a schematic view showing an embodiment of optical information recording / reproducing based on the present invention. Here, 1 is an optical card as shown in FIG. 2, which is mounted on a mounting table 17 fixed to a belt 20. The belt 24 is wound around the pulleys 19 and 18, and the motor 2
1 moves in the direction of arrow d, and along with this, the optical card 1 also moves in direction d. Therefore, on the surface of the optical card 1, the light beam 32 emitted from the optical head 16 is scanned in the b or c direction in FIG. The optical head 16 is composed of a semiconductor laser 11, a collimator lens 12, a beam splitter 13, an objective lens 14, and a photodetector 15. The light beam 32 is emitted from the semiconductor laser 11 and is converged as a minute spot on the optical card 1 by the objective lens 14. The reflected light of the light beam 32 from the optical card passes through the objective lens 14 again, is separated from the incident light by the beam splitter 13, and is detected by the photodetector 15. The signal detected by the photodetector 15 is sent to the signal demodulation circuit 22, the tracking control circuit 23, and the focus control circuit 24, and the focus control circuit 24 and the tracking control circuit 23 cause the objective lens 14 to move in the optical axis direction, respectively. Move in the direction perpendicular to the optical axis to perform AF and AT.

A stepping motor 28 moves the optical head 16 in the direction perpendicular to the plane of the drawing, thereby moving the irradiation position of the light beam in the direction of FIG. The motor 21 includes a motor drive circuit 25.
The optical card is moved and stopped under the control of. Further, the drive speed of the motor 21 is detected by a speed detection circuit 29, and this speed detection circuit 29, via a time measurement circuit 30,
It is connected to a laser drive circuit 31 that drives the semiconductor laser 11. Furthermore, the signal demodulation circuit 22, the stepping motor 28,
The motor drive circuit 25 and the laser drive circuit 31 are connected to a central processing unit (CPU) 27 via an interface 26, respectively.

When performing recording or reproducing operation in this device, the motor 21 and the stepping motor 28 are driven by the control of the CPU 27, and the light beam scans the data recording area 3 as described with reference to FIG. At this time, the light beam 32 from the semiconductor laser 11 is always shown on the optical card in FIG.
_It has a power of _WL or P _R , and at the time of recording, it is modulated with the power P _WH according to the recording signal input from the terminal C ₁ . Also, during reproduction, a reproduction signal is output from the terminal C ₂ . When the operation is completed, the motor 21 is stopped, and the light beam is kept standing still while having the power P _WL or P _R. When the motor 21 is stopped, the speed detecting circuit 29 detects that the relative speed V between the optical card and the light beam has become zero, and activates the time measuring circuit 30. Here, in the time measuring circuit 30,
When the predetermined time T _OFF is set and the time t after V = 0 becomes equal to T _OFF , an irradiation stop signal is sent to the laser drive circuit 31 to stop the emission of the semiconductor laser 11. To do. If the next operation is started during t <T _OFF and V = 0, the time measuring device is reset.
T _OFF is set to T _OFF <T _S (T _OFF = T _S / 2), where T _S is the time for recording with the stationary light beam having the optical power P _WL or P _R described above. In addition, the set time T _OFF may be configured to be changeable stepwise by an external switching switch or continuously by a volume or the like in accordance with the recording sensitivity of the optical card.

The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, although the stationary state of the light beam is directly detected from the motor in the embodiment, the time may be started according to a signal from the CPU controlling the operation of the optical card.
The speed may be detected by the signal read from the photodetector. Further, the present invention is not limited to the recording and reproducing apparatus as described above, but a recording-only apparatus,
It can also be applied to a reproduction-only device.

[Effects of the Invention] As described above, the optical information recording / reproducing method of the present invention consumes the light beam by making the light beam stand by at the end of the track on the card in a non-operating state when recording or reproducing is not performed. An optical information recording / reproducing method that realizes high-speed recording or reproducing with low power is realized.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an optical information recording / reproducing apparatus of the present invention, FIG. 2 is a schematic plan view showing an example of an optical card used in the apparatus of the present invention, FIG. 3 (A), (B) is a diagram for explaining the optical power on the optical card at the time of recording and reproducing, respectively, and FIG. 4 is a schematic diagram showing how the spot of the light beam is scanned on the optical card. 1 …… Optical card 11 …… Semiconductor laser 21 …… Motor 29 …… Speed detection circuit 30 …… Time measurement circuit 31 …… Laser drive circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumiaki Kawaguchi, 53 Imaiue-cho, Nakahara-ku, Kawasaki-shi, Kanagawa Canon Inc., Kosugi Plant (72) Kenichi Suzuki, 53 Imaiue-cho, Nakahara-ku, Kawasaki, Kanagawa Prefecture Canon Kosugi Plant (72) Inventor Masayuki Usui 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Matsuoka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuhiko Matsuoka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hideki Hosoya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Akio Aoki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuo Minoura Tokyo Metropolitan Univ. 3-30-2 Shimomaruko, Ta-ku, Canon Inc. (56) References JP-A-59-140671 (JP, A)

Claims (1)

[Claims] 1. An optical information recording / reproducing method for recording or reproducing information by irradiating a card-shaped optical information recording medium having a plurality of linear tracks with a light beam, the medium comprising: And a light beam are reciprocated relative to each other to perform a recording or reproducing operation, and a relative movement of the medium and the light beam along a track is stopped to move the light beam to the track of the medium. Optical information recording / reproducing method, characterized in that it has a non-operation stage in which it stands by in a stationary state at the end of the.