JPH0231341A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To hold optimum recording and emitting power without receiving the influence of a change in the emitting characteristic of a laser diode even when there is the change of an environmental temperature by providing a means to reset the emission quantity of the laser diode in the case there is the temperature change more than prescribed temperature width. CONSTITUTION:A temperature sensor 1 is provided near a laser diode 3 in an optical head 2 and a temperature is converted to an electric signal. Then, temperature information are sent through an A/D converter 4 to a CPU5. After that, the CPU5 takes in the output of the temperature sensor in each constant time, for example, and judges whether the temperature width is within the constant temperature width or not. When the temperature width is not more than the constant temperature width, a power check is not executed however, when there is the change more than the constant temperature width, the power check is executed for optical output reset. Then, even when the temperature is changed, an optical output is held to a suitable optical output level. The power check is executed without giving any influence to the data recording area of a defocus condition, etc. Thus, even when the recording and emitting power is set, recording is not executed with the optical output level which is not suitable for the data recording area.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical information recording/reproducing device provided with temperature compensation means for the light emission characteristics of a laser diode.

[Prior Art] In recent years, optical information recording and reproducing devices that can record and reproduce information on an optical recording medium (hereinafter referred to as an optical disk) by condensing and irradiating a light beam have been developed. It was put into practical use.

Laser diodes, which can be miniaturized, are widely used as means for generating the light beam.

By the way, the current vs. emission characteristics of a laser diode (hereinafter referred to as
It is abbreviated as IL characteristic. ) shows temperature dependence, as shown in FIG. Generally, the threshold current increases as the temperature increases. For example, threshold current i thl at temperature T1
When the temperature rises to T2, the threshold current i th2 increases, and the light output with respect to the current change in the stable light emission region, that is, the luminous efficiency is calculated from (P 2 - P 1) / (12 - 11) to (
P2-P1)/(i4-i3).

Therefore, in order to obtain stable power, the rear (back) emitted light of the laser diode is detected and feedback is applied to the drive circuit to maintain the optical output constant.

The feedback control described above is generally performed during reproduction light emission, but not during recording. Therefore, the light emission output level tends to change depending on the temperature. A conventional example that solves this problem is Japanese Patent Application Laid-Open No. 154335/1982.

In the conventional example described above, temperature compensation is performed using the output of the temperature sensor in a closed feedback loop.

[Problems to be Solved by the Invention] Therefore, there is a drawback that the temperature sensor is easily influenced by variations in temperature sensors.

In addition, in the conventional example above, the luminous efficiency is assumed to be constant regardless of the temperature, so in areas where the environmental temperature is greatly different or where the temperature change is large, the light output may deviate from the appropriate value even if feedback control is performed. There are cases where it gets put away. For example, when recording in cold weather and when recording in hot weather, the slope of the laser diode's current vs. optical output will be different, which is different from the case where the slope is constant, so the emitted light power during recording will be different. Even if feedback control is performed, a situation may occur in which the value deviates from the optimum value. Furthermore, an error remains in the power immediately after recording due to the time constant of the feedback loop. In short, when recording, the actual recording area is illuminated with the recording light emitting power, the light emitting power is detected, and the desired recording light emitting power is set. It is not possible to perform recording with a certain recording light emitting power.

Therefore, there is a drawback that the incidence of errors in reading recorded data increases.

The present invention has been made in view of the above-mentioned points, and has an object to maintain a desired luminous intensity even if luminous efficiency changes depending on temperature, and to set a desirable recording luminous power without affecting the recording area. The object of the present invention is to provide an optical information recording/reproducing device that can perform the following functions.

[Means and effects for solving the problem] In the present invention, in the basic configuration diagram shown in FIG.
The A/D converts temperature into an electrical signal.
Temperature information is sent to CPtJ5 via converter 4. C.P.
U5 performs the processing routine shown in FIG. 1(B). In the power check, the power table is rewritten in a defocused state so that the light output is appropriate even at a low temperature T, and the laser light control circuit 6 is set to a desired control state. Thereafter, for example, the CPU 5 takes in the output T of the temperature sensor at fixed time intervals t, and checks whether the temperature range is within a fixed temperature range ΔT, that is, IT-
It is determined that Tol≧ΔT, and if it is less than ΔT, power check is not performed, but if there is a change greater than ΔT,
A power check is performed to reset the light output, and the light output level is always maintained at an appropriate level even if the humidity changes. Furthermore, since the power check is performed without affecting the data recording area, such as in a defocused state, the data recording area is not recorded at an inappropriate optical output level even when the recording light emission power is set.

[Example] Hereinafter, the present invention will be specifically described with reference to the drawings.

Figures 2 to 7 relate to the first embodiment of the present invention;
The figure shows the configuration of the control system of the first embodiment, FIG. 3 shows the temperature change detection means, FIG. 4 shows the processing routine for setting the light emission amount, and FIG. 5 shows the structure of the light emission amount setting part. , FIG. 6 shows how the instruction table is rewritten for setting recording light emission m, and FIG. 7 shows how light is emitted with recording light emission power in order to set the instruction value of the instruction table to a desired value.

As shown in FIG. 2, in the optical information recording/reproducing apparatus 11 of the first embodiment, an optical head 13 is arranged opposite to an optical disk 12 which is rotationally driven by a spindle motor (not shown). This optical head 13 is attached to a movable base (not shown), and is moved in the radial direction of the optical disc 12 (that is, the optical disc 12) by optical head moving means such as a voice coil motor.
It is movable in the direction R) across two concentric or spiral tracks.

The optical head 13 has a laser diode 14,
The light beam of this laser diode 14 is transmitted to the optical disk 12.
By irradiating the beam with focused light, information can be recorded and reproduced. In this laser diode 14, a monitoring photodetector 15 such as a pin photodiode 15 is connected to a housing 16.
It is enclosed inside. However, laser diode 1
The front light of 4 is used for recording or reproduction, while the back light is received by a pin photodiode 15, and the light emission amount of the laser diode 14 is controlled by the photoelectric conversion output.

The optical head 13 has the following configuration.

The front light of the laser diode 14 is a diffused light beam, and after being made into a parallel light beam by the collimator lens 19, it enters the polarizing beam splitter 21 as, for example, P-polarized light, and is transmitted almost 100%. The transmitted light of the polarizing beam splitter 21 is converted into a circularly polarized light beam by a quarter-wave plate 22, and then condensed by an objective lens 23 and irradiated onto the optical disk 12.

After passing through the objective lens 23, the reflected light from the optical disk 12 is converted into S-polarized light by the 1/4 wavelength plate 22, enters the polarizing beam splitter 21, and is almost 100% reflected.
The light is incident on the critical angle prism 24. The light beam reflected by the slope of the critical angle prism 24 is received by a photodetector 25 disposed in the far field, facing the output end face of the prism 24.

The photodetector 25 is formed of, for example, four-divided light-receiving elements, the output of which is input to an addition/subtraction circuit 26, and a reproduced signal is generated by the sum (addition) of the four light-receiving elements. or,
A focus error signal FER is generated by a pair of differential outputs divided by a groove parallel to the radial direction R, and a focus error signal FER is generated by a pair of differential outputs divided by a groove parallel to the tangential direction of the track. An error signal TER is generated. Both signals FER and TER are supplied to the drive circuit 27.
A servo system is constructed in which the voltage is applied to a focusing coil 29 and a tracking coil 31 which form a lens actuator via a servo system 28 to maintain the objective lens 22 in a focused state and a tracking state.

Incidentally, the light emission amount control means for controlling the light emission level of the laser diode 14 has the following configuration.

The light emission of the laser diode 14 is detected by the monitor detection circuit 32.
It is input to a photodiode 15 forming a . For example, an anode of this photodiode 15 is connected via a resistor R to a negative voltage source -Vc. The seven nodes of the photodiode 15 have a potential corresponding to the amount of light input to the photodiode 15, and this potential becomes the output of the monitor detection circuit 32.

Note that FIG. 2 shows only the configuration of the main part of the monitor detection circuit 32, and in an actual monitor detection circuit, the efficiency of the laser diode 14 used is normalized, and the luminescent source and the monitor output have a constant relationship. A compensation circuit or adjustment circuit is provided which is set so that .

The monitor output of the monitor detection circuit 32 is input to the laser light control circuit 33, and this monitor output generates a laser light amount control signal for controlling the light emitting current supplied from the laser drive circuit 34 to the laser diode 14. By the control signal of this laser light amount control circuit 33, the laser drive circuit 3
The current supplied from the laser diode 4 to the laser diode 14 is controlled so that its light emission intensity is at an appropriate value.

By the way, a temperature sensor 35 is provided near the laser diode 14 in the optical head 13, and the temperature sensor 35 allows the optical output to be set and maintained at an appropriate level even if the temperature of the laser diode 14 changes. There is.

The configuration of the surrounding area of this temperature sensor 35 is shown in FIG.

For example, a thermistor is used as the temperature sensor 35, and forms a gain setting resistor of the temperature detection circuit 41.

The non-inverting input terminal of the amplifier A1 forming the temperature detection circuit 41 is grounded via the resistor R1, and the inverting input terminal is connected to the resistor R1.
It is connected to the output terminal via a resistor R3 and a temperature sensor 35. This output terminal is connected to the second inverting input terminal of the second amplifier via a resistor R4 forming an inverting amplifier circuit 42. The non-inverting input terminal of this second amplifier A2 is grounded via a resistor R5, and the inverting output terminal is connected to the output terminal via a resistor R6.

The output of the temperature detection circuit 41 has a negative polarity,
It is inverted and amplified by the inverting amplifier circuit 42 and becomes positive. In addition, if the temperature sensor 35 has a negative temperature coefficient whose resistance value decreases as the temperature rises, the inverting amplifier circuit 4
The output No. 2 is a temperature detection output whose output level tends to decrease as the temperature rises. The output of this inverting amplifier circuit 42 is converted into a digital quantity by an A/D converter 43, and
It is input to PU44. This CPIJ44 judges whether there is a change exceeding a certain temperature range ΔT from the temperature taken in at the time of initial setting or resetting, and if there is a change in temperature exceeding ΔT according to the processing routine shown in FIG. ,
Reset the recording light emission amount of the laser diode 14, and
If the temperature changes within 1, do not perform this reset,
Continue to operate in that setting state.

The CPLI performs the process shown in FIG. 4 as a reference clock C and uses the count output of a counter 45 that counts K to determine the temperature change width at regular time intervals t.

In the processing routine shown in FIG. 4, the counter 45 as a check timer counts up the clock CLK, and judges whether or not the counter value corresponding to a certain time t has been reached. A/D converter 4
3, and check whether the absolute value of the temperature difference T-TO from the previous temperature TO (the initial setting of the recording light emitting table or the previous setting) exceeds a certain temperature range of 6, that is. Determine whether or not the limit has been exceeded. However, if the limit is not exceeded, the counter 4
5 is reset and time measurement is performed again, and if the limit is exceeded, it is determined whether the recording light emission (write) table resetting condition is met. In other words, even if ΔT is exceeded, the characteristics of current versus light output may not change much, so in that case there is no need to force the light table to be reset. On the other hand, depending on the temperature range, if the temperature exceeds the above 6, the change in the current vs. optical output characteristics will be large (for example, the amount of change in the slope of the current vs. optical output shown in FIG. 11 will be large). You will need to reset the light table. Therefore, when the conditions for resetting the light table are satisfied, the light table resetting process is performed, the check timer is initialized, and the initial temperature of the laser diode 14 is set, that is, the reset temperature is maintained.

In FIG. 3, the CPtJ 44 selects the A/D converter 43 via the chip selector 46 based on the address.

The above write table is reset as shown in FIG.

The output of the monitor detection circuit 32, which detects light emission based on the anode potential of the photodiode 15, is input to the sample and hold circuit 51 of the laser light amount control circuit 33, and after being sampled and held, it is converted into a digital quantity by the A/D conversion circuit 52. and is input to the arithmetic circuit 53.

The arithmetic circuit 53 converts the signal into an analog signal via the instruction circuit 55 according to the instruction value of the recording light emission instruction table 54 as shown in FIG. Recording light is emitted by a signal.

(In addition, this measurement signal is held at the reproduction light emission level in the case of L11.) The output of the monitor detection circuit 32 during this recording light emission is sampled and held, and is transmitted via the A/D conversion circuit 52. The input luminophore is input to the arithmetic circuit 53, and depending on whether the input luminophore matches the target value, it is caused to emit light again with the corrected instruction value and set to the target value.

Further, when setting the recording light emission amount, the recording light emission current is superimposed on the reproduction light emission instruction current. Therefore, the output detected by the monitor detection circuit 32 during regeneration light emission is input to the holding circuit 57 via the switch SW of the regeneration light path control circuit 56, and the regeneration light emission instruction current is held in the holding circuit 57. . After the reproduction light emission instruction current is held by the holding circuit 57, the switch SW is switched to the recording light emission amount setting side as shown in FIG.

Further, the recording light emission amount setting is performed in a defocused state in an area not used for data recording, such as the inside of the innermost track Tr1 shown in FIG. 2, for example. Therefore, even if light is emitted with the recording light emission power, the data recording area is not affected.

The following describes how the above configuration can cope with the case where the previous current vs. light output characteristic changes from the recording light speckle level at the previously set temperature due to a change in environmental temperature or the like.

The temperature information detected by the temperature sensor 35 is taken in by the CPU 44 at fixed time intervals t, and the temperature difference from the previous temperature is checked. Therefore, when a temperature change with a certain temperature range of 61 or more is detected, a check is made to see if the temperature change is a condition that requires rewriting the table, and if rewriting is necessary, An instruction to reset the recording light emission is sent to the controller of the optical head 13 to cause it to perform the operation of setting the light table.

Before setting this light table, the reproduction light emission instruction current is held in a holding circuit 57 that holds the output current of the reproduction light a control circuit 56, and then the switch SW is switched as shown in FIG. The reproduction light emission current of the drive circuit 34 is determined by the output value of the holding circuit 57.

In other words, as shown in Figure 7, when reproducing light is emitted in the reproducing light emission mode, the light emission amount is PRR, and when setting the recording light emission amount, the measurement light emission mode (in this mode, the light emission power and the playback power are set). ), and the light emission current according to the recording light emission instruction table 54 is superimposed on the level at which light is emitted by the current held by the holding circuit 57.

That is, as shown in FIG. 6, the arithmetic circuit 53 calculates the light emission instruction value "11" corresponding to the outermost track A according to the recording light emission instruction table 54 provided in the arithmetic circuit 53.
111000'', enters the laser drive circuit 34 via the instruction circuit 55 and applies a measurement signal to emit recording power.The initial light emission instruction value ``11111000'' is, for example, a roughly known value. For example, it can be set with an approximate instruction value based on the standard of the laser diode used.On the other hand, if it is not the initial setting, the light emission instruction value at the previous setting is written.

The recording light emission ω at the first instruction value for the track A is detected by the monitor detection circuit 32, sampled and held by the sample hold circuit 51, and is also detected by the A/D converter 5.
2, it is converted into a digital signal and taken into the arithmetic circuit 53. Note that this recording luminescence amount is determined by the sample and hold circuit 5.
After a short period of time when sampling is possible at 1, the amount of light emitted is returned to the reproduction light amount. The arithmetic circuit 53 compares the captured light emission amount with the target light emission amount, calculates the difference, and calculates an instruction value for correcting the difference when they do not match. In FIG. 6, the first instruction value is a light emission level slightly lower than the target value, and a slightly larger instruction value "11111011" is input to the laser drive circuit 34 via the instruction circuit 55. Similarly, the arithmetic circuit 53 calculates whether the amount of light emitted at this instruction value is the target value or not, and if there is a difference, outputs a corrected instruction value. Such operations are repeated, and when the light emission instruction value for track 8 matches the target value, the light emission instruction value for that track 8 is stored in the recording emission instruction table 54, and its contents are updated. Note that when emitting light at each instruction value, the instruction value in the recording light emission instruction table 54 may be updated each time, and the update may be stopped when the instruction value matches the target value.

When the setting of the light emission amount for the track A is completed, the same operation is performed for tracks other than the track A, for example, B and C, until each of them matches the target value. FIG. 7 shows how this is done for three rotating tracks A, B, and C.

In this figure, recording power is emitted three times for each track A, B, and C, but for example, if the target value of light emission is obtained with the initial instruction value, the recording power is emitted once for that track. It ends with. In this way, the light emission levels for three different tracks are determined, and the light emission instruction values for the tracks between these are determined by a straight line connecting these tracks. Through this interpolation, the light emission instruction values for all the tracks on the optical disc 12 are obtained, and the light emission instruction table 5 in the arithmetic circuit 53 in FIG.
4 is replaced with the indicated value.

In this way, the setting of the light emission instruction value for the case of emitting recording power light in the recording emission mode is completed, and when data is actually recorded in the data section of each track in the user area, the recording emission is performed according to the above instruction value. .

According to the first embodiment, the recording light emission amount can be set to the optimal target value not only when the device 11 is started, but also when there is a temperature change exceeding an appropriate temperature range.
Even if the luminous efficiency of the laser diode 14 changes due to deterioration due to long-term use or the like, or even in an environment where the temperature changes, the target luminous intensity can always be maintained with high precision.

Therefore, if you set the target value to the optimal light emission instruction value in advance,
After that, recording light is emitted at the optimum light emission amount at all times, so recording bits (
bits) etc. are kept under the same conditions. Therefore, the error rate of reading errors during reproduction can be sufficiently reduced, and a highly reliable recording and reproducing apparatus can be realized.

Note that the reproduced light emission level is controlled by APC control so that the monitor detection output is at a constant level, so even if there is a temperature change, it is not affected.

FIG. 8 shows the main parts of a second embodiment of the present invention.

In this second embodiment, a high frequency current is superimposed on the laser diode 14 together with a direct current during reproduction.

Therefore, a DC current is supplied to the laser diode 14 from the laser drive circuit 34 during reproduction, and a high-frequency current from the high-frequency superposition circuit 62 is superimposed on the DC current based on a high-frequency superposition control signal from the high-frequency superposition control circuit 61. It is supplied as follows.

Note that the operation of high frequency superimposition can be controlled by a control signal.

This embodiment has a configuration in which a high frequency superimposition control circuit 61 and a high frequency superposition circuit 62 are newly provided in FIG. 2 or FIG. 5, as shown in FIG.

Therefore, in the regenerative light emission mode, the high frequency superimposing circuit 6
The high frequency current of 2 is superimposed on the laser diode 14, while the high frequency current is not superimposed in the recording light emission mode.
is driven. Therefore, the current vs. light emission characteristics are utilized in two operating curves as shown in FIG.

A solid curve shows the current vs. light emission σ characteristic of the laser diode 14 in the absence of high frequency superimposition, and in the case of recording light emission, light is emitted according to this curve.

On the other hand, the dotted curve shows the current vs. light emission characteristics in the case of high frequency superimposition, and in the case of regenerated light emission, light is emitted according to this curve.

In this embodiment, when recording light is emitted in FIG.
Regeneration light emission instruction current 1 when high frequency superimposition is operating
The target recording light emission amount (in this case, the recording light emission level of A) is obtained by adding the recording light emission instruction current IOpw to 0PR. (On the other hand, conventionally, the error current ■ΔR when changing from high frequency superposition to no high frequency superposition is added to the regeneration light emission instruction current 10PR,
Furthermore, the recording light emission addition current Iw is added to obtain the desired recording light emission amount.In this case, since there are variations in the high frequency power value generated by the high frequency superimposition circuit, it is necessary to adjust ■ΔR, and the adjustment The disadvantage is that it becomes complicated. ) In order to record as described above, a recording light emission amount setting means for setting the recording light emission amount to a target value is provided as in the first embodiment.

Thus, the recording light emission amount setting operation is performed at the time of startup or when there is a temperature change of more than a certain width.

For example, if there is a temperature change exceeding T from the previous temperature to a constant temperature n, it will be detected by CPtJ44 (Figure 3),
For example, the CPU 44 transmits a control signal to the high frequency superimposition control circuit 61, stops the operation of the high frequency superposition circuit 62, and causes the write table to be reset.

In FIG. 9, the reproduction light emission instruction current -10P corresponding to the reproduction light emission level when the high frequency superimposition circuit 62 is operating.
R is held in a holding circuit 57 that holds the output current of the reproduction light emission amount control circuit 56.

Therefore, when setting the recording luminophore, switch SW
is switched to the state shown in FIG.
The reproduction light emitting current is determined by the output value of the holding circuit 57.

In this case, in FIG. 7, during regenerative light emission in the regenerative light emission mode, the regenerative light emission instruction current 1 on which the high frequency current is
Light is emitted at 0PR, and the amount of light emitted is PPP (shown by the dotted line)
It is. On the other hand, in the measurement light emission mode in which measurement light is emitted for setting the recording light emission amount (in this mode, there are light emission power and reproduction power emission times), the reproduction light emission power level PRR is determined by the current held in the holding circuit 57. The light is held at the level emitted by. In addition, since the high frequency current of the frequency 1 circuit 62 is stopped from being supplied to the laser diode 14 via the high frequency superimposition control circuit 61 by the control signal, the high frequency current is The reproduced light emission level PRR is lower by the light emission level corresponding to the superimposed current.

Therefore, the calculation circuit 53 performs the same calculation as in the first embodiment, and rewrites the contents of the recording light emission instruction table so that they match the target value even at this temperature.

FIG. 10 shows the main parts of a third embodiment of the present invention.

This third embodiment differs from the first embodiment shown in FIG.
When the CPU 44 rewrites the light table, the CPU 44 writes temperature information TU and TL to the latch 71 indicating how much the temperature has changed from the temperature T at which the write table needs to be rewritten.

Here, TLI represents digital data at a temperature higher than T, and TL represents digital data at a lower temperature. The data stored in this latch 71 is applied as reference data to a window type digital comparator 72, and compared with the temperature information input via the A/D converter 43, and it is determined whether the temperature information deviates from the range between TtJ and TL mentioned above. In this case, the comparator 72 outputs an interrupt signal to the CPU 44 to cause the laser light amount control circuit 33 to perform a processing routine for changing the light table three times. In addition, when performing fortune-telling on the light table, the CPU 44 outputs a movement signal to the optical head moving means 74 to move the optical head 13 to, for example, the innermost track Tri.
At the same time, an offset voltage 75 for defocusing is superimposed on the focus error signal and outputted to the focusing coil 29 side to set the defocus state. (In this case, turn the focus servo
Make it FF. ) If the temperature range that requires rewriting the light table is uncertain, as in the case of initial settings, you can make an analogy with the standard temperature of the laser diode or set a smaller width. good. Also, if the temperature exceeds a certain range, CP
It is also possible to interrupt U44 and have the temperature determine whether or not to rewrite the write table.

In each of the embodiments described above, the optical output is monitored using the back light of the laser diode, but the optical output may be monitored by detecting the front light. Further, the present invention can also be applied to a magneto-optical recording method.

[Effects of the Invention] As described above, according to the present invention, there is provided a means for resetting the amount of light emitted by the laser diode even when there is a temperature change exceeding an appropriate temperature range, so that the change in the environmental temperature can be avoided. Even in such a case, the optimum recording light emitting power can be maintained without being affected by changes in the light emitting characteristics of the laser diode.

[Brief explanation of the drawing]

FIG. 1 shows a conceptual configuration of the present invention, FIG. 1(A) is a conceptual configuration diagram, FIG. 1(B) is an explanatory diagram of its operation, and FIGS. 2 to 7 are a first embodiment of the present invention Regarding the example, Fig. 2 is a schematic block diagram of the first embodiment, Fig. 3 is a block diagram of the temperature detection section, and Fig. 4 shows whether or not to set the light table according to the detected temperature difference. A flowchart of the process, Figure 5 is a block diagram of the part that sets the recording light emission amount, Figure 6 is an explanatory diagram showing how to change the instruction table, and Figure 7 is a diagram showing how to change the recording light emission power according to the instruction value of the instruction table. An explanatory diagram showing the light output when the light is emitted, FIG. 8 is a configuration diagram of the main part of the second embodiment of the present invention,
Fig. 9 is an explanatory diagram showing the relationship between current and light emission amount when there is superimposition of high-frequency current, Fig. 10 is a block diagram showing the main part of the third embodiment of the present invention, and Fig. 11 is a diagram showing the relationship between current and light emission. FIG. 3 is an explanatory diagram showing how the relationship between outputs changes depending on temperature. 1.35... Temperature sensor 2,13... Optical head 3.14... Laser diode 4.43... A/D converter 5.44... CPU 6.33... Laser light a Control circuit 12... Optical disk 53... Performance n circuit Figure 2 (A) Figure CB) aT:'ie, (SHJritt constant number (M+■) To; Previous power table damage Q reduction 1 ]” Tl Te Rokku Rihe Lbi 5E Shimatsu Figure 3 Figure! RILLRO No. 3 Figure 4 Figure 8 Figure 9 Figure 6 Figure 7 Reproduction!! Light-←--Tame) Sadame Light ---Tatami 1 Enyu diagram

Claims (1)

[Claims] In an optical information recording/reproducing device using a laser diode as a light source for recording/reproducing, a temperature sensor for detecting the temperature of the laser diode, and when this temperature sensor changes by an appropriate temperature range or more, the temperature of the laser diode is 1. An optical information recording and reproducing apparatus, comprising means for resetting an operating current without affecting a data recording area of a recording medium.