JP2001076365A - Optical information recording / reproducing device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent return light of a test light beam reflected by an optical card or a card mounting table from being projected onto a monitor formed in the same package as a light source, and to constantly output a light source during recording and reproduction. Provided is an optical information recording / reproducing apparatus which performs stable recording / reproducing with a predetermined power. The light source includes a light source that irradiates a light beam onto a medium surface of an information recording medium on a mounting table, and a light detector that detects light from the light source, and a light amount of the light source based on a detection signal of the light detector. In the optical information recording apparatus that controls the mounting table, the treatment is performed so that the light of the light source is not reflected, and a test shot is performed before mounting the information recording medium on the mounting table, And adjusting means for adjusting the amount of light of the light source based on a value of a detection signal of the photodetector in a state where return light from a medium is not detected by the photodetector.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a light source for irradiating a light beam onto a medium surface of an information recording medium, and a photodetector for detecting light from the light source, and the light amount of the light source based on a detection signal from the photodetector. The present invention relates to an optical information recording / reproducing device for controlling the optical information recording / reproducing.

[0002]

2. Description of the Related Art Various types of information recording media for recording and reproducing information using light, such as a disk, a card, and a tape, have been known. Among them, for example, a card-shaped optical information recording medium (hereinafter, referred to as an “optical card”) is a portable and relatively large-capacity information recording medium which cannot be erased and rewritten at present, and has this characteristic. It is expected to be applied in fields that are advantageous.

FIG. 10 is a schematic plan view of an optical card.
As shown in FIG. 10, the optical card has an optical recording area C1.
The optical recording area C1 includes an information track Ta for recording information and a tracking track as a guide for automatic tracking (AT) for controlling a light spot so as not to deviate from a predetermined information track during information recording and reproduction. Tb and many Tb are arranged in parallel.

Further, the optical recording area C1 is provided with a home position HP serving as a reference position for accessing the information track Ta, and the information track Ta is assigned a track number (not shown) in order from the one closer to the home position HP. are doing. Access to the target information track is performed by a seek operation of moving the light spot in a direction perpendicular to a large number of tracks arranged in parallel, and by scanning the information track with the light spot.

When information is actually recorded and reproduced, auto-focusing (AF) control is performed so that a light spot is focused on a recording medium surface. The AT control and the AF control are general techniques that have been frequently used in optical information recording / reproducing apparatuses.

FIG. 11 is a block diagram showing a conventional optical card information recording / reproducing apparatus 1. In FIG. 11, reference numeral 1 denotes an optical card information recording / reproducing device (hereinafter, referred to as "drive"), and reference numeral 2 denotes a CPU which is a higher-level control device. The drive 1 records and reproduces information based on a command issued from the CPU 2.

[0008] Reference numeral 8 denotes an optical card C which is introduced into a card mounting table (not shown) waiting at a predetermined position in the drive 1 via a transport mechanism (not shown), and a card mounting unit holding the optical card C. The motor is for reciprocating the table in the X direction and for discharging the optical card C out of the drive 1. A sensor 7 is provided near the card insertion slot 6, and when the sensor 7 detects that the optical card C is inserted, the optical card C is transported to a predetermined position. Some devices do not include a card mounting table.

Reference numeral 21 denotes an irradiation optical system including a light source. When recording and reproducing information, the light beam emitted from the irradiation optical system 21 is spot-irradiated onto the optical card C, and the light spot and the optical card C are relatively positioned. The light spot scans the information track Ta reciprocally. Reference numeral 34 denotes a photodetector that receives reflected light of a light spot applied to the optical card C, and reproduces recorded information based on a detection signal of the photodetector 34.

Reference numeral 13 denotes an AF actuator for driving a part of the irradiation optical system 21 to move the light spot in the Z direction, that is, in a direction perpendicular to the card surface, to perform AF control. An AT actuator for partially controlling the AT spot to move the light spot in the Y direction, that is, the direction perpendicular to both the R direction and the Z direction.

Reference numeral 3 denotes a nonvolatile memory EPRO.
MPU with built-in M and RAM, which controls various parts such as the card feed motor 8 and the like,
2 and exchange data. Reference numeral 10 denotes an AT / AF control circuit that drives the AF actuator 13 and the AT actuator 14 based on the detection signal of the photodetector 34 to perform AT control and AT control.

Reference numeral 4 denotes a modulation / demodulation circuit for reproducing the detection signal of the photodetector and demodulating the reproduction signal to reproduce the original recording data. Reference numeral 5 denotes a light source drive circuit for modulating and controlling the intensity of a light source (in the irradiation optical system 21) (not shown) by the output of the modulation / demodulation circuit 4, thereby recording information by light modulation on the information track Ta.

FIG. 12 is a schematic diagram showing the internal structure of the card mounting table and the optical head. In FIG. 12, reference numeral 9 'denotes a card abutting portion, and reference numeral 41 denotes a card guide, which is attached to the card mounting table 9. 22 is a laser diode (hereinafter referred to as “LD”) as a light source, and 33 is L
D22 is a photodetector (monitor) formed in the same package as D22, and detects the output of the light emitting end of the rear surface of the LD chip 22 '. Reference numeral 26 denotes a non-polarizing beam splitter, which has a ratio of transmittance to reflectance of 1: 1.

Next, the card transport operation will be described with reference to FIG. The optical card C inserted from the card insertion slot is conveyed in the direction of the arrow X from the left side of the drawing into the gap E between the card mounting table 9 and the card guide 41 and hits the abutting portion 9 ′ of the card mounting table 9. Stop at the position. At this time, the optical card C is abutted against each direction reference plane by a biasing means (not shown) provided on the card mounting table 9 in the Z direction and the Y direction. Is maintained.

When the optical card C is being conveyed, the card mounting table 9 and the optical head 20 are stopped at predetermined positions. At this time, the light beam emitted from the optical head 20 is moved to the home position on the optical card C. In general, it stops in a positional relationship such as to irradiate the HP. And
When the transport of the optical card C is completed, the LD 22 emits light, the AF and AT are pulled in at the home position HP, and an AF and AT control loop is formed to enable recording and reproduction.

Next, the recording / reproducing operation will be described with reference to FIG. The light beam emitted from the LD 22 is
After being split into three light beams by the diffraction grating 25 via the collimator lens 23, the light beams reach the non-polarizing beam splitter 26. Since the ratio of the transmittance to the reflectance of the non-polarizing beam splitter 26 is 1: 1, about 50% of the light beam emitted from the LD 22 reaches the objective lens 29.

Then, the 3 divided by the diffraction grating 25
The two luminous fluxes are the tracking track T ₁ on the optical card C,
An image is formed on the information track T ₂ and the tracking track T ₃ as light spots S ₁ , S ₂ and S ₃ . Optical card C
The light irradiated upward is reflected here, reaches the non-polarizing beam splitter 26 via the objective lens 29, and about 50% of the reflected light beam is projected on the photodetector 34 via the detection optical system 30.

The detection optical system 30 is composed of a spherical lens 31 and a cylindrical lens 3 arranged at an angle of 45 ° with respect to the track.
2 and performs AF control by the astigmatism method and AT control by the three-beam method based on the output of the photodetector 34.

In the AT control, a deviation (AT error) of the light spot irradiated from the optical head 20 from the information track T _{2 is performed.}
And an AT actuator 1 for driving the objective lens in the tracking direction (Y direction in FIG. 11).
4 by feeding it back.

In the AF control, the deviation (A) of the light spot irradiated from the optical head 20 from the in-focus state on the medium surface is considered.
F error) and detects this information in the AF direction (FIG. 11).
(In the Z direction) by feeding back to the AF actuator 13 that drives the objective lens 29. Then, the AT / AF control is performed, and the recording and reproduction of information are performed by the optical head 20 reciprocating in the arrow X direction and the optical card C reciprocating in the arrow Y direction in FIG. L
The output light amount of D22 is different between recording and reproduction, and is controlled so that each has a desired power on the medium surface.

An optical information recording / reproducing apparatus for recording / reproducing information on / from an optical information recording medium such as an optical card C uses a semiconductor laser such as an LD 22 as a light source. It is predetermined in consideration of the characteristics of the recording medium, the recording speed (irradiation time), and the like.

However, as can be seen from the LD drive current vs. optical output characteristics in FIG. 13, when the LD 22 is driven with the constant current I, the optical output P (P) is changed by the temperature T (T ₁ <T ₂ <T ₃ ).
_1> P _2> P ₃₎ is varied. For this reason, the pit formation becomes unstable during recording, and the S
/ N degradation.

Therefore, conventionally, a feedback loop is formed in the LD drive circuit, and a part of the light emitted from the LD 22 is detected by a photodetector (monitor) 33 formed in the same package of the LD 22. Automatic output control is performed so as to reach the target value. The target value is obtained by power adjustment performed at the time of manufacturing, and is a monitor output value when a predetermined power is obtained on the medium surface. This target value is stored in a nonvolatile memory built in the device.

[0023]

However, in general, since the feedback loop of the automatic output control has a large time constant, it takes time for the high power during recording to stabilize.
There was a problem that the recording pit shape at the start of writing was not stable. As a method for solving this problem, there is a method in which a drive current value for obtaining a predetermined power is measured in advance by trial-testing an LD, and this value is used as an initial current to perform feedback.

On the other hand, without forming a feedback loop, a drive current value for obtaining a predetermined power on the medium surface by test firing is measured in advance, and thereafter, during recording, the measured drive current is applied to the LD to perform recording. There is also.

In any of the methods, it is determined whether or not the predetermined power on the medium surface has reached a target value, that is, a monitor output value corresponding to the predetermined power on the medium surface at the time of the trial shooting. are doing.

However, as described above, if test firing is performed while the light beam emitted from the optical head is stopped in a positional relationship such that the light beam irradiates the home position on the optical card, the light beam emitted by the test firing is not shown. As shown in FIG. 14, (a) the optical card when the optical card is held on the card mounting table, and (b) when the optical card is not held, the surface is parallel to the optical card and perpendicular to the light beam. The upper surface of the card mounting table, which is a surface, is irradiated.

Then, part of the return light reflected on the optical card or the upper surface of the card mounting table is transmitted through the objective lens 29 to the L port.
The luminous flux emitted from D is projected on the monitor through the same optical path, and as a result, a problem arises in that a predetermined power on the medium surface cannot be obtained.

In FIG. 12, F denotes a test light beam emitted from the front light emitting end of the LD chip 22 ', R denotes a bold line, the test light beam F is a reflected light beam reflected on the medium surface of the optical card C, and B denotes a reflected light beam.
The thin lines marked with indicate the luminous flux emitted from the rear emission end of the LD chip 22 ′. The luminous flux at the time of the conventional test operation will be described with reference to FIG. Since the test light beam F and the reflected light beam R pass through the same optical path, the line indicating the test light beam F and the line indicating the reflected light beam R overlap in FIG.

The test light beam F emitted from the front light-emitting end of the LD chip 22 ′ is converted into a parallel light beam by the collimator lens 23. On the other hand, the light beam B emitted from the rear surface light emitting end of the LD chip 22 'is projected on the monitor 33 as divergent light. The test beam F, which has become a parallel beam, reaches the objective lens 29 via the diffraction grating 25 and the non-deflection prism 26.

The test light beam F is converged by the objective lens 29, is irradiated as a light spot on the medium surface of the optical card C, and the light beam reflected on the medium surface is projected onto the objective lens 29 again. The reflected light flux that has been converted into a parallel light flux again by the objective lens 29 is transmitted to the non-deflection prism 26 and the diffraction grating 2.
The light enters the collimator lens 23 through 5. The reflected light flux is converged by the collimator lens 23, becomes a light spot at the light emitting end of the front surface of the LD chip 22 ', which has a conjugate relationship with the medium surface, and thereafter becomes divergent light.

Since the monitor 33 is arranged such that the center of the light beam emitted from the LD chip 22 ′ becomes the center of the monitor 33, the reflected light beam that has become divergent light is projected on the monitor 33. Further, when the test light beam is reflected not on the optical card C but on the upper surface of the card mounting table 9, the reflected light beam which has become a divergent light is projected on the monitor 33 although the position where the reflected light beam forms a light spot is different. It will not change.

As described above, in the conventional test operation, the reflected light of the test light beam is projected on the monitor. Next, a problem caused by this will be described below.

FIG. 15 is a diagram in which the monitor output value A and the power B on the medium surface when driven by the constant current I are plotted and connected by a line. FIG. 15A shows the case where there is no return light.
FIG. 15B shows the case where a part of the return light reflected on the optical card C or the upper surface of the card mounting table 9 is projected on the monitor 33. FIG. 15C shows the automatic output control in the state shown in FIG. This shows the case where the operation is performed.

In the case of FIG. 15A, assuming that the monitor output value is A ₀ and the power on the medium surface is B ₀ , FIG.
In the case of 5 (b), the monitor output value increases by ΔA of the return light and becomes A ₁ (> A ₀ ). At this time, since the power on the medium surface does not change, the power on the medium surface is B ₀ .

Here, when the automatic output control is performed with the target value of the monitor output as A ₀ , the monitor output value becomes A ₀ as shown in FIG. At this time, since the may include return light amount in the monitor output values A _0, and in accordance with the target value monitor output value ΔI only driving current corresponding to the return light is small. As a result, the power on the medium surface decreases by ΔB corresponding to the drive current ΔI, and B ₁ (<B ₀ )
Becomes

As described above, when the return light of the test light flux reflected by the optical card C or the upper surface of the card mounting table 9 is projected on the monitor 33, the power on the medium surface becomes smaller than the predetermined power. Are unstable, and the S / N of a reproduced signal is deteriorated during reproduction.

Therefore, the present invention prevents the return light of the test light beam reflected by the optical card or the card mounting table from being projected onto a monitor formed in the same package as the light source, and always keeps the light source output during recording and reproduction. It is an object of the present invention to provide an optical information recording / reproducing apparatus that performs stable recording / reproducing with a predetermined power.

[0038]

In order to solve the above-mentioned problems, the present invention provides a light source for irradiating a light beam on a medium surface of an information recording medium on a mounting table, and a photodetector for detecting light from the light source. An optical information recording device that controls the light amount of the light source based on a detection signal of the photodetector, wherein the mounting table is treated so that the light of the light source is not reflected, and the information recording is performed. Performing a test firing before placing the medium on the mounting table, and adjusting the light amount of the light source based on the value of the detection signal of the photodetector in a state in which return light from the medium is not detected by the photodetector. And adjusting means.

Further, the present invention comprises a light source for irradiating a light beam onto a medium surface of an information recording medium, and a photodetector for detecting light of the light source, and the light source of the light source is detected based on a detection signal of the photodetector. In an optical information recording device for controlling the amount of light, a first test firing is performed prior to insertion of the information recording medium, and a detection signal of the photodetector is detected in a state where return light from the medium is not detected by the photodetector. A storage means for storing the value of the detection signal of the photodetector in a state where the return light is detected by the photodetector, And adjusting means for adjusting the light amount of the light source based on the value of the detection signal by the first trial and the value of the detection signal by the second trial stored in the storage means.

[0040]

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

(Embodiment 1) FIG. 1 shows Embodiment 1 of the present invention.
5 is a flowchart showing a trial shooting operation. 2 and 3
3 is a flowchart showing each operation of a first trial (step S1) and a second trial (step S6) of FIG.

FIG. 4 is a block diagram of the LD drive circuit.
4, reference numeral 51 denotes a current-voltage converter for converting a photocurrent generated from the monitor 33 into a voltage; 52, an A / D converter for converting the output of the current-voltage converter 51 into a digital signal;
Is a D / A converter that outputs an analog signal based on data sent from the MPU 3, 54 is a constant current source whose current value can be controlled by the output of the D / A converter 53, and 55 is a constant current that is controlled by the recording signal WD. A switch for turning on / off the source 54. The optical card information recording / reproducing device and the AT / AF control circuit of the present embodiment are the same as those in FIG.

The operation of the present embodiment will be described with reference to FIGS. Note that the optical information recording / reproducing apparatus of the present embodiment will be described as not including a card mounting table.

When the power is turned on by the operator, MP
U3 detects whether or not there is an optical card in the apparatus, and if so, outputs a control signal to the motor 8 to eject the optical card C out of the apparatus. On the other hand, if not, the first irradiation is started immediately [Step S1].

Here, the first irradiation will be described. To perform the first irradiation, first, the switch 55 is turned on,
With D22 continuously emitting light, the output of the D / A converter 53 is gradually increased from 0V by the MPU3. The constant current source 54 supplies a current corresponding to the voltage to the LD 22 based on the output of the D / A converter 53, thereby causing the LD 22 to emit light and performing a test shot. At this time, the optical card C
Is not inserted, so that the luminous flux of the test
It is irradiated to other than.

The output of the monitor 33 which detects the output of the light emitting end of the rear surface of the LD chip is input to the MPU 3 via the current-voltage converter 51 and the A / D converter 52. High power: It is determined whether or not the output of the monitor 33 has reached the monitor output value A ₀ corresponding to P _H [Step S2].

The recording high power in Step S2: If it is determined not to reach the value corresponding to P _H repeats step S2 gradually increase the output of the D / A converter 53,
If it is determined in step S2 that the value corresponding to the high power for recording: P _H has been reached, that is, if it is determined that the output of the monitor 33 has reached the initial value A ₀ , D / A
The set value _DH of the converter 53 is recorded [Step S3], and the first test firing ends here.

Subsequently, it is determined by the sensor 7 whether or not the optical card C has been inserted (step S4). When the insertion of the optical card C is detected, the card is transported into the apparatus by a card transport mechanism (not shown), and the MPU 3 determines whether the loading operation has been completed normally [Step S].
5].

When the loading operation is completed normally, the second test firing is started (step S6). At this time, the light beam emitted from the optical head 20 is applied to the home position HP of the optical card C. The MPU 3 supplies D / A converter 53 with D
_H is set, and the switch 55 is turned on again to make the LD 22 emit light continuously [step S7].

[0050] Then, store the output value A ₁ of the current-voltage converter 51, A / D converter 52 monitor 33 at this time obtained through the step S8], the second sighting is completed. MPU3 After sighting completion monitors the output of the monitor 33, the output of the monitor 33 to form a feedback loop to adjust the value of the D / A converter 53 so that A _1.

Then, the LD 22 emits light and the AF is pulled in at the home position HP.
A control loop and an AT control loop are formed, and information can be recorded / reproduced. The above operation is controlled by a CPU (not shown) which is the highest control device in the apparatus.

As described above, in the present embodiment, the first test firing is performed when the test firing light beam is applied to an area other than the optical card, and the monitor output is the target value A stored in the nonvolatile memory in advance.
The set value D _H of the D / A converter which becomes ₀ is obtained. Further, the second test firing is performed when the test firing light beam is irradiated on the optical card, and the monitor output A ₁ when the D / A converter is set to _DH.
The calculated, thereafter, the monitor output value is driving the LD such that the A _1.

Therefore, even when the reflected light from the medium surface is projected on the monitor, the power on the medium surface can be set to a predetermined power, and stable pit formation can be performed during recording.

In the present embodiment, the automatic output control of the recording LD is performed by forming a field back loop after the second test firing, but the test firing is performed for each optical card or each recording operation, and the second test firing is performed. Monitor output value A obtained by test shooting
The D / A converter set value Dx when it becomes ₁ is stored for each test shot, and the same effect is obtained in a device that drives the LD 22 by setting Dx in the D / A converter until the next test shot. is there.

[0055] Further, in the present embodiment is a target value of the determined monitor output value A ₁ a feedback loop in the second sighting, a monitor output value A ₁ was calculated by the second sighting first
Of the monitor output value A ₀ ′ at the time of
A ₁ ′), and (A ₀ + ΔA) may be used as the target value of the feedback loop. According to this, (A ₀ −A ₀ ′)
D / A and A / D conversion errors are reduced, and the power on the medium surface becomes more accurate.

Further, in the present embodiment, the first test firing is performed immediately after the power is turned on. However, after stopping the optical card C at the reference position in the apparatus, the optical card C and the optical head are relatively moved. Alternatively, the first test firing may be performed after a positional relationship in which the test light beam is not irradiated onto the optical card. As a result, the time interval between the first test firing and the second test firing is shortened, so that it is less likely to be affected by a temperature change, and the predetermined power can be more accurately set on the medium surface.

Further, since the second trial light beam is applied to the home position on the optical card, the AF pull-in and the AT pull-in are performed immediately after the end of the second trial firing, so that information recording / reproduction can be performed. Good accessibility to.

(Embodiment 2) FIG. 5 is a flowchart showing a test shooting operation of Embodiment 2. Only the difference between the timing of the test firing and the criterion for the start of the test firing is different from that of the first embodiment. The operation of the present embodiment will be described with reference to FIG. 4, FIG. 5, and FIG.

When the power is turned on by the operator, MP
U3 detects whether or not the optical card C is present in the apparatus, and if so, outputs a control signal to the motor 8 to discharge the optical card C to the outside of the apparatus. On the other hand, if not, it is immediately determined by the sensor 7 whether or not the optical card C has been inserted (step S11).

When the sensor 7 is shielded from light by the optical card C, the output level changes from H to L. Therefore, when the output of the sensor 7 changes to L, the MPU 3 inserts the optical card C. Is detected. Then, when it is detected that the optical card C is inserted, the first test firing is started [Step S12].

When the test firing of the LD 22 is performed and the set value D _H of the D / A converter is stored in the same manner as in the first embodiment, the D / A converter corresponding to the reproduction power: P _L is set in the same procedure. The value D _L is stored. During the first test run,
The optical card C is transported by a card transport mechanism (not shown), and the test beam and the optical card C are relatively moving. When the first test firing is completed, the MPU 3 sets the optical head 20
It is determined whether or not the optical card C has arrived until the light flux emitted from the optical card C reaches the positional relationship of being emitted onto the optical card C [Step S13].

The output of the sensor 7 changes from L to H again when the optical card C completely passes, and at this time, the positional relationship is such that the light beam emitted from the optical head 20 is emitted onto the optical card C. When the output of the sensor 7 changes to H and the arrival at the card is detected, the MPU 3 starts the second test firing (step S14).

At this time, the AF control loop has not been formed yet, and the MPU 3 sends a false AF error signal to the AF control circuit 11 and applies a current based on the signal to the focusing actuator 13. As a result, the objective lens 29 is moved to a position where the medium surface does not become the in-focus surface, and the luminous flux that has been shot reaches the medium surface after a light spot is finally formed. Therefore, the medium surface is in a defocused state.

During the second trial firing, the optical card C is being transported by a card transport mechanism (not shown), and the trial luminous flux and the optical card C are relatively moving.
The power per unit area of the test light beam on the recording medium surface is equal to or less than the power per unit area required for recording, and the optical card C is moving. The irradiation time to be performed is shorter than the irradiation time required for recording with the power per unit area of the test light beam on the recording medium surface.

Therefore, the information is not recorded on the information recording medium, and the information recording medium is not deteriorated. Storing the monitor output value at the time of setting the D _H to the first embodiment as well as D / A converter, followed by storing the monitor output value at the time of setting the D _L to the D / A converter. When the second test firing is completed, the optical card C stops at the reference position in the apparatus.

Then, the LD 22 emits light and the AF is pulled in at the home position HP.
A control loop and an AT control loop are formed, and information can be recorded / reproduced. In the present embodiment, since the test firing operation is performed after the optical card C is inserted into the device until the optical card C stops at the reference position, the time interval between the first test firing and the second test firing is short, and the temperature change Less susceptible.

Further, since the test firing is performed for each optical card, it is hardly affected by a change in temperature, and a predetermined power can be accurately set on the medium surface. Furthermore, AF is stopped immediately after the reference position is stopped.
Since the information can be recorded and reproduced by performing the pull-in and the AT pull-in, the access to the information is good.

Further, in the present embodiment, the LD2 is used as a light source.
2, the same effect as that of the embodiment can be obtained if the light source is a light source having a monitor in the same package and the light output is controlled based on the monitor output signal.

Third Embodiment Next, a third embodiment will be described. In the present embodiment, the card mounting table 5 is provided in the apparatus.
9 will be described.

FIG. 6 is a perspective view of the card mounting table 59 of the third embodiment. The difference from the conventional card mounting table 9 shown in FIG. 12 is that a through hole 60 which is an opening is provided in a portion irradiated with a test light beam. The upper surface of the card mounting table 59 and the optical card held by the card mounting table 59 are parallel to each other, and the upper surface of the card mounting table 59 is a surface perpendicular to a light beam from a light source (not shown) as in the related art.

FIG. 7 is a side view of FIG. 6, showing a state from the optical card insertion direction. FIG. 8 is a flowchart showing the test shooting operation of the present embodiment. The LD drive circuit is the same as in the first embodiment. Next, FIGS.
The test firing operation of the present embodiment will be described with reference to FIGS.

When the power is turned on by the operator, MP
U3 detects whether or not the optical card C is mounted on the card mounting table 59, and if the optical card C is mounted, the motor 8
And outputs a control signal for discharging the optical card C out of the apparatus. On the other hand, when the optical card C is not placed, the sensor 7 immediately determines whether or not the optical card C is inserted (step S21).

At this time, the optical head 20 and the card mounting table 59 are stopped at predetermined reference positions, respectively, and the objective lens 29 is directly above the through hole 60 provided in the card mounting table 59. In addition, the through hole 60 is set to be directly below the home position HP on the optical card C when the optical card C is mounted on the card mounting table 59. When the sensor 7 is shielded from light by the optical card C, the output level changes from H to L.
And the MPU 3 detects that the optical card C has been inserted when the output of the sensor 7 changes to L.

When the MPU 3 detects that the optical card C has been inserted, the MPU 3 causes the test beam emitted to the through-hole 60 to form a light spot at the end face position of the through-hole 60 corresponding to the upper surface of the card mounting table 59. Fake AF error signal
Output to the control circuit 11. Then, a current based on the signal is applied to the focusing actuator 13.

The magnitude of the dummy AF error signal is appropriately determined from the positional relationship between the optical head 20 and the card mounting table 59, and is stored in advance. As a result, the objective lens 29 moves from the position where the medium surface becomes the focusing surface to a position further closer to the card mounting table 59 [Step S2]
2].

When the movement of the objective lens 29 is completed, the trial shooting is started [Step S23]. In addition, the trial shot is optical card C
Is performed before moving to above the through hole 60. The MPU 3 gradually increases the current value applied to the LD 22 and reaches the monitor output value A ₀ corresponding to the recording power: P _H in which the output of the monitor 33 detecting the output of the light emitting end of the rear surface of the LD chip is stored in advance. [Step S2]
4].

If it is determined in step S4 that the value does not reach the value corresponding to the recording power: P _H , the applied current is further increased to reach the value corresponding to the recording power: P _H. that is, until the monitor output value is determined to have reached a _0, repeat steps S24. When the monitor output value reaches A _0, and stores the set value D _H of the D / A converter 53 Step S25]. Thus, the test shooting is completed.

The test light beam is applied to the upper surface of the card mounting table 59 perpendicularly, becomes convergent light by the objective lens 29, and becomes a light spot at the end surface of the through hole 60 corresponding to the upper surface of the card mounting table 59. . At this time, the test luminous flux, which has become a light spot, is radiated to the through hole 60 provided in the card mounting table 59, and is divergent light without being reflected by the card mounting table 59 and passes below the card mounting table 59. To go.

The light that has passed through the card mounting table 59 is divergent light, and the amount of light reflected by the housing and again passing through the through hole of the card mounting table 59 and projected onto the monitor via the objective lens 29 is very small. is there. For this reason, it is considered that there is no problem in determining the set value of the D / A converter. In this embodiment, the set value of the D / A converter is set to a value corresponding to the predetermined power on the medium surface. It is possible to perform stable pit molding at the time of recording.

In the present embodiment, the test shooting is performed only once.
Although the example has been described, for example, the first
Power for recording in the trial shooting of P_HOf the D / A converter corresponding to
Value D _HAfter that, the optical card C is placed on the card mounting table 59.
The luminous flux emitted from the optical head 20 is held by an optical card.
When irradiating C, D / A converter_HSet
A second test shot is performed, and the monitor output value A at this time₁Seeking
Since then, the monitor output value is A₁LD22 so that
May be driven.

In this manner, the value D _H of the D / A converter corresponding to the recording power: P _H is set and a test shot is performed to obtain a monitor output value A _{1 including} an error due to the reflected light from the medium surface. Is set as the target value, the power on the medium surface can be set to a desired power even when the medium surface reflected light is projected on the monitor.

For this reason, for example, even when the optical card C is left in the apparatus for a long time and the re-testing for eliminating the influence of the temperature change is performed, the optical head 20 and the card mounting table 5 are not used.
You can test fire immediately without moving 9
Since it is possible to promptly shift to the subsequent recording / reproducing operation, the information can be easily accessed.

Further, the optical head 20 and / or the card mounting table 59 are moved, and the optical head 20 is moved.
The test firing may be performed after the positional relationship in which the luminous flux emitted from the camera is not irradiated on the card mounting table 59. Even in this case, the amount of reflected light projected on the monitor is small, and the same effect is obtained.

There is no problem even if the optical card C is held on the card mounting table 59.
Even after the device has been left in the apparatus for a long time, even if re-testing is performed to eliminate the effect of temperature change, the optical card C is once moved from the card mounting table 59 by the operation of discharging the optical card C, and after the test firing, A test operation is performed by a relatively simple operation of moving the optical head 20 or the card mounting table 59, not a complicated operation of holding the optical card C on the card mounting table 59 by transporting the optical card C. Can be.

Further, in this embodiment, the test light beam forms a light spot at the portion corresponding to the upper surface of the optical card C and the end face 60 of the through-hole formed in the card mounting table 59.
The size of the through hole 60 provided in the card mounting table 59 can be minimized, and a decrease in rigidity of the card mounting table 59 can be minimized.

Further, in the present embodiment, the through hole 60 is provided at a position directly below the home position HP on the optical card C when the card mounting table 59 holds the optical card C. If the optical card C is held by the card mounting table 59 without moving the head 20 or the card mounting table 59, AF and AT are pulled in immediately to enable recording and reproduction of information. Good nature.

In this embodiment, the card mounting table 59 is provided with the through hole 60 parallel to the optical axis. However, for example, an inclined hole inclined with respect to the upper surface of the card mounting table 59 may be provided. Good. The angle of inclination is determined so that the light beam reflected by the inclined hole is irradiated outside the objective lens aperture, or the light beam reflected by the first surface 61 of the inclined hole is reflected again by the second surface 63 as shown in FIG. By guiding the reflected light flux to the lower side of the card mounting table 59, the reflected light flux is not projected on the monitor, and the same effect is obtained.

In addition to providing a hole such as the through hole 60 and the inclined hole so as not to generate return light, for example, by applying a light absorbing material to a portion corresponding to the through hole 60, reflected light can be obtained. May not be caused.

In this embodiment, the output of the light emitting end of the rear surface of the LD chip is detected by the monitor in the same package as the light source. However, the same applies to an apparatus for detecting the output of the light emitting end of the front surface of the LD chip by the monitor in the same package. The effect is obtained.

In the first to third embodiments, an optical card is used as an information recording medium. However, the same effect can be obtained in another information recording medium, for example, an optical information recording / reproducing apparatus for recording / reproducing information on / from an optical disk. . Embodiment 1
In Nos. 1 to 3, the output of the light emitting end of the rear surface of the LD chip is detected by a monitor in the same package as the light source.

[0091]

As described above, according to the present invention, the test recording is performed before the information recording medium is placed on the information recording medium so that the light from the light source is not reflected. The light amount of the light source is adjusted based on the value of the detection signal of the light detector in a state where the light source is not detected by the light detector.

Further, according to the present invention, the first test firing is performed prior to the insertion of the information recording medium, and the value of the detection signal of the photodetector is stored in a state where the return light from the information recording medium is not detected by the photodetector. Then, after inserting the information recording medium, the second test firing is performed, the value of the detection signal of the photodetector is stored in a state where the return light is detected by the photodetector, and the light source of the light source is stored based on the value of the detection signal. Adjust the light intensity.

Therefore, it is possible to prevent the return light of the test light beam reflected by the optical card or the card mounting table from being projected onto a monitor formed in the same package as the light source, and to always keep the light source output at the time of recording / reproduction at a predetermined power. Further, it is possible to provide an optical information recording / reproducing apparatus that performs stable recording / reproducing. Thereby, it is possible to secure a stable pit formation at the time of recording and a sufficient S / N ratio of a reproduced signal at the time of reproduction.

[Brief description of the drawings]

FIG. 1 is a flowchart of a trial shooting operation according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart of step S1 in FIG.

FIG. 3 is a flowchart of step S6 in FIG. 1;

FIG. 4 is an LD drive circuit block diagram.

FIG. 5 is a flowchart of a trial shooting operation according to the second embodiment.

FIG. 6 is a schematic perspective view of a card mounting table according to the embodiment of the present invention.

FIG. 7 is a side view of FIG. 6;

FIG. 8 is a flowchart of a trial shooting operation according to the third embodiment.

FIG. 9 is a side view of FIG. 6;

FIG. 10 is a schematic plan view of an optical card.

FIG. 11 is a block diagram showing an optical card recording / reproducing device.

FIG. 12 is a schematic view of a conventional optical head and a card mounting table.

FIG. 13 is a diagram showing LD drive current versus light output characteristics.

FIG. 14 is a view showing a state in which reflected light from a conventional test beam returns to an objective lens.

FIG. 15 is a diagram showing changes in monitor output value and medium surface power under each condition.

[Explanation of symbols]

 Reference Signs List 2 CPU 3 MPU 5 Light source driving circuit 9 Conventional card mounting table 9 'Card attaching section 11 AF control circuit 12 AT control circuit 13 AF actuator 20 Optical head 22 Semiconductor laser (LD) 22' LD chip 23 Collimator lens 25 Diffraction grating 26 Beam splitter 29 Objective lens 32 Cylindrical lens 33 Monitor 34 Photodetector 51 Current-voltage converter (I / V) 52 A / D converter 53 D / A converter 54 Current source 55 Switch 59, 59 'Card according to the present invention Mounting table 60 Through hole provided in card mounting table 59 61 First surface of through hole provided in card mounting table 59 '63 Second surface of through hole provided in card mounting table 59' C Optical card C1 Optical recording medium HP Home Position

Claims (8)

[Claims] A light source for irradiating a light beam to a medium surface of an information recording medium on a mounting table; and a photodetector for detecting light of the light source, wherein the light source detects the light source based on a detection signal of the photodetector. In the optical information recording / reproducing apparatus for controlling the amount of light, the mounting table is treated so that light from the light source is not reflected, and a test shot is performed before mounting the information recording medium on the mounting table. Optical information, comprising adjusting means for adjusting the amount of light of the light source based on a value of a detection signal of the photodetector in a state where return light from the information recording medium is not detected by the photodetector. Recording and playback device. 2. A light source for irradiating a light beam onto a medium surface of an information recording medium, and a photodetector for detecting light from the light source, wherein the light amount of the light source is controlled based on a detection signal of the photodetector. In the optical information recording / reproducing apparatus, a first test firing is performed prior to the insertion of the information recording medium, and a return signal from the information recording medium is not detected by the photodetector. Storage means for storing a value, performing a second trial after insertion of the information recording medium, and storing a value of a detection signal of the photodetector in a state where the return light is detected by the photodetector; An optical device comprising: an adjusting unit that adjusts a light amount of the light source based on a value of the detection signal obtained by the first trial and a value of the detection signal obtained by the second trial stored in a storage unit. Information Reproducing apparatus. 3. A second test firing after the information recording medium is mounted on the mounting table, and the light source is determined based on a value of the detection signal by the test firing and a value of the detection signal by the second test firing. 2. The optical information recording / reproducing apparatus according to claim 1, wherein the light amount is adjusted. 4. The method according to claim 1, wherein the treatment is to provide an opening, and the return light is prevented from being detected by the photodetector by irradiating the opening with the light beam. 2. The optical information recording / reproducing device according to 1. 5. The optical information recording / reproducing apparatus according to claim 1, wherein a light beam emitted from the light source by the test emission forms a light spot at the treatment portion. 6. The optical apparatus according to claim 1, wherein the treatment is performed so that the information recording medium is located below a home position of the recording medium when the information recording medium is placed on the mounting table. Information recording and reproducing device. 7. The optical information recording / reproducing apparatus according to claim 4, wherein the opening is obliquely opened with respect to the mounting table. 8. The method according to claim 1, wherein the test irradiation or the first irradiation is performed when a lens for narrowing the light beam to the information recording medium and the information recording medium are relatively moving. Or the optical information recording / reproducing device according to 2.