JPH11190619A - Emission angle measuring device and emission angle measuring method of light source for optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly measure the emission angle of a light source even in the case of the emitting point position of the light source to be a measured object, being shifted in an emission angle measuring device for the light source for an optical pickup. SOLUTION: A device for measuring an emission angle of a light source 11 for an optical pickup mounted to a mount member 10 with a required reference face P1, to the reference face P1 is provided with a pressure contact member 2 with a contact face Q1 with which the reference face P1 of the mount member 10 is brought into pressure contact, a light quantity distribution measuring part 3 that can measure the distribution of light quantity from the light source 11 by moving along the light emitting direction of the light source 11, and an emission angle computing part 6 for computing the emission angle of the light source 11 to the reference face P1 on the basis of light quantity distribution at two different spots obtained by the light quantity distribution measuring part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emission of a light source for an optical pickup suitable for measuring a light emission angle of the light source for an optical pickup mounted on a mount member having a required reference surface with respect to the reference surface. The present invention relates to an angle measurement device and a light emission angle measurement method.

[0002]

2. Description of the Related Art An optical pickup is a light source module used in an optical disk device. For example, in addition to a semiconductor laser (laser diode: LD) as a light source, the optical pickup reflects light from the semiconductor laser to a magneto-optical recording medium. And a photodetector (photodiode: PD) for receiving reflected light from the magneto-optical recording medium and transmitting reflected light from the magneto-optical recording medium having a data component.

In an optical pickup, a semiconductor laser is mounted at a predetermined position on the upper surface of a submount having a required reference surface using a jig or the like. Here, it is necessary to arrange the semiconductor laser so as to emit light in a predetermined direction with respect to the reference plane in order to prevent loss of emitted light. Therefore, the emission angle of the semiconductor laser with respect to the reference plane is required. A measurement is being made. In particular,
The light-receiving element moves on an arc centered on the vicinity of the emission point of the semiconductor laser, and the above-mentioned emission angle is directly measured.

[0004]

However, in the conventional semiconductor laser emission angle measuring device, when the position of the emission point of the semiconductor laser to be measured is shifted, that is, when the sub-laser to which the semiconductor laser to be measured is mounted is attached. If the set position of the mount is shifted, there is a problem that the emission angle of the semiconductor laser cannot be accurately measured.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been developed to accurately measure the emission angle of a semiconductor laser even when the position of the emission point of the semiconductor laser to be measured is shifted. It is an object of the present invention to provide a light emitting angle measuring device and a light emitting angle measuring method for a pickup light source.

[0006]

SUMMARY OF THE INVENTION Therefore, an emission angle measuring apparatus for an optical pickup light source according to the present invention measures an emission angle of an optical pickup light source mounted on a mount member having a required reference surface with respect to a reference surface. Device for performing
The light amount distribution from the light source was measured by moving along the light emission direction of the light source behind the pressing member and the pressing member with the contact surface against which the reference surface of the mount member was pressed. And a light emission angle calculation unit for calculating a light emission angle with respect to a reference plane of the light source based on the light amount distribution at two different points obtained by the light distribution measurement unit. (Claim 1).

Further, according to the light-emitting angle measuring device for an optical pickup light source of the present invention, in the light-emitting angle measuring device for an optical pickup light source according to the first aspect, the light quantity distribution measuring unit moves linearly behind the pressing member. And a light receiving section with a slit provided in the carrier section so as to be movable in a direction intersecting the moving direction of the carrier section. .

In the light emitting angle measuring device for a light source for an optical pickup according to the present invention, when the reference surface of the mount member is pressed against the contact surface of the pressing member, the light amount distribution measuring section is more than the pressing member. By moving along the light emission direction of the light source behind, the light intensity distribution from the light source at two different points is measured. Thereafter, the light emission angle calculation unit calculates the light emission angle of the light source with respect to the reference plane based on the light amount distribution at two different points obtained by the light amount distribution measurement unit.

Further, according to the method for measuring the light emission angle of a light source for an optical pickup according to the present invention, when measuring the light emission angle of the light source for an optical pickup mounted on a mount member having a required reference surface with respect to the reference surface, With the surface pressed against a predetermined contact surface, the light intensity distribution at two points at different distances from the reference surface along the light emission direction of the light source is measured, and then the phase on the light intensity distribution at these two points is measured. The light emitting angle of the light source with respect to the reference plane is obtained from the corresponding measurement point (claim 3).

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a configuration of a light emission angle measuring device of a light source for an optical pickup according to an embodiment of the present invention. The emission angle measuring device 1 shown in FIG.
Is a semiconductor laser [light source for optical pickup: laser diode (L)] mounted slightly overhanging on a submount (mounting member) 10 having a required reference plane P1.
D)] is to measure the light emission angle of 11 with respect to the reference plane P1. The pressing member 2 is fixed to the guide member 8, and the guide (the light emitting direction of the semiconductor laser) behind the pressing member 2 is guided. The light amount distribution measuring unit 3 is slidably provided on the member 8.

The pressing member 2 has a contact surface Q1 against which the reference surface P1 of the submount 10 is pressed. Further, the light amount distribution measuring unit 3 linearly moves along the guide member 8 in the light emitting direction (Y-axis direction) of the semiconductor laser 11 behind the pressing member 2, thereby obtaining the light amount distribution from the semiconductor laser 11. Can be measured. Specifically, the light amount distribution measuring unit 3
Comprises a carrier section 4 having a predetermined length in a direction (X-axis direction) intersecting with the moving direction (Y-axis direction), and a light-receiving section 5 for receiving light emitted from the semiconductor laser 11. Have been.

In this case, the carrier part 4 is
The light receiving portion 5 is capable of linearly moving along the guide member 8 (along the Y-axis direction) further behind, and the light receiving portion 5 is provided with a slit 5A capable of moving on the carrier portion 4.
B. Note that a photodiode (PD) or the like is used as the light receiving unit 5. The light amount distribution measuring unit 3 calculates the light amount distribution from the semiconductor laser 11 as
The light quantity distribution “a” at the point A shown in FIG. 1 and the light quantity distribution “b” at the point B behind the point A are measured. That is, the light amount distribution measuring unit 3 linearly moves along the light emitting direction of the semiconductor laser 11 and, at two points A and B at a short distance and a long distance parallel to the reference plane P1 of the submount 10, the light amount distribution “a”. , "B" are measured.

By the way, the light emitting angle measuring device 1 is provided with a light emitting angle calculating unit 6.
, The two points A and B obtained by the light quantity distribution measuring unit 3
The light emission angle of the semiconductor laser 11 with respect to the reference plane P1 (not shown in FIG. 1, but this light emission angle is represented by θ as will be described later) is calculated based on the light amount distributions “a” and “b” in FIG. I am asking for it.

To this end, the light emission angle calculation unit 6 is provided with a data storage area 14, a measurement point detection unit 15, and an angle calculation unit 16, as shown in the functional block diagram of FIG. Here, the data storage area 14 stores the light amount distribution “a” at two points A and B obtained by the light amount distribution measurement unit 3,
This is to temporarily store the measurement data of “b”.
A first data storage unit 14A that stores measurement data of the light quantity distribution “a” at the point, and a second data storage unit 14B that stores measurement data of the light quantity distribution “b” at the point B.
It is composed of Note that this data storage area 14
It is composed of a memory (RAM).

The measurement point detection unit 15 calculates the corresponding measurement points S and T on the light amount distributions “a” and “b” at two points A and B from the measurement data stored in the data storage area 14. Is what you want. Here, as shown in FIG. 1, the measurement points S and T are, for example, light amount distributions “a” and “b”.
The upper maximum point (peak) can be obtained. In determining the measurement points S and T, preprocessing such as smoothing processing on the detection signal is performed as necessary.

Further, the angle calculator 16 calculates the emission angle θ of the semiconductor laser 11 with respect to the reference plane P1 from the measurement points S and T obtained by the measurement point detector 15. Specifically, the angle calculation unit 16 calculates a straight line (reference line) L that is parallel to the guide member 8 and passes through the obtained measurement point S and a straight line M that connects the obtained measurement points S and T. The angle θ to be formed is obtained by calculation, and this is obtained as the light emission angle θ of the semiconductor laser 11.

Here, the functions corresponding to the above-described measuring point detecting section 15 and angle calculating section 16 are actually executed by a light emitting angle calculation program recorded on a recording medium such as a disk device or a CD-ROM (not shown). The program is read out to a memory (RAM) (not shown), the program is activated and executed by the central processing unit (CPU), thereby realizing the operation of the CPU.

In FIG. 1, reference numeral 7 denotes a power supply for driving the semiconductor laser 11, and reference numeral 12 denotes a display for displaying a result of calculation of the light emission angle θ of the semiconductor laser 11 by the light emission angle calculator 6, and the like. Reference numeral 13 denotes a printing unit that prints the calculation result and the like. A procedure for measuring the emission angle θ of the semiconductor laser 11 using the emission angle measuring device 1 with the above configuration will be described with reference to the flowchart shown in FIG.

First, the light emitting angle measuring device 1 is started up (step S1), and the vacuum is turned on (step S2). Then, open the light-shielding box (step S
3) The submount 10 (work) to be measured is replaced and clamped (step S4). Then, the light-shielding box is closed (step S5), and after the preparation for measurement is OK, the switch for the automatic operation is turned on (step S6). The operations in steps S1 to S6 are performed manually.

When the switch is turned on in the above-mentioned step S6, the light emission angle measuring apparatus 1 performs the following step S7.
The operations from S17 to S17 are performed automatically. First, the probe needle (not shown) is lowered (step S7),
A voltage is applied to the semiconductor laser (LD) 11 by the power supply 7 (step S8), and the semiconductor laser 11 emits light.

Then, the light quantity distribution measuring section 3 moves to the point A (first measurement point) (step S9), and measures the light quantity distribution "a" at the point A (step S1).
0), move to point B (second measurement point) (step S11), and measure the light amount distribution “b” at point B (step S12). That is, in the light emitting angle measuring device 1, the light amount distribution from the semiconductor laser 11 is measured by the light amount distribution measuring unit 3 in a state where the reference surface P1 of the submount 10 is pressed against the contact surface Q1 of the pressing member 2. Thus, at two points A and B at different distances from the reference plane P1 along the light emitting direction of the semiconductor laser 11 (specifically, at two points A and B at different positions parallel to the reference plane P1). Light amount distributions “a” and “b” are measured.

Thereafter, the light quantity distribution measuring section 3 moves to the origin position (step S13), and the application of the voltage to the semiconductor laser (LD) 11 by the power supply 7 is released (step S1).
4) The semiconductor laser 11 is extinguished. Then, the probe needle is raised (step S15), and a message indicating that the measurement is completed is displayed on the display unit 12 (step S15).
16).

Finally, in the light emission angle calculation section 6, the light emission angle θ of the semiconductor laser 11 is obtained by calculation, and the obtained light emission angle θ is displayed on the display section 12 (step S1).
7). At this time, the mechanical part returns to the preparation of the next sample. That is, in the emission angle calculation unit 6, first, the measurement point detection unit 15 detects the corresponding measurement points on the light amount distributions “a” and “b” at the two points A and B obtained by the light amount distribution measurement unit 3. S and T are required. Then, the angle calculator 16 calculates the emission angle θ of the semiconductor laser 11 with respect to the reference plane P1 from the obtained measurement points S and T by the calculation as described above.

Here, when the light quantity distribution as shown in FIG. 1 is obtained as the light quantity distributions “a” and “b” at the two points A and B, the reference line L and the straight line M Angle θ
Is 0 °, the emission angle θ of the semiconductor laser 11 is 0 °.
°. Therefore, in this case, it is understood that the semiconductor laser 11 is mounted straight on the submount 10 (to emit light in a direction perpendicular to the reference plane P1).

On the other hand, the light quantity distribution “a” at two points A and B,
When a light amount distribution as shown in FIG. 3 is obtained as “c”, a straight line M connecting the above-mentioned reference line L, the obtained measurement point S and the measurement point U on the light amount distribution “c” is obtained. Is determined as the emission angle θ of the semiconductor laser 11. Therefore, in this case, it can be seen that the semiconductor laser 11 is mounted on the submount 10 obliquely (in a state shifted by an angle θ with respect to a direction orthogonal to the reference plane P1).

As described above, according to the light-emitting angle measuring apparatus 1 of the light source for the optical pickup according to one embodiment of the present invention,
The light emission angle θ of the semiconductor laser 11 with respect to the reference plane P1 is calculated based on the light amount distributions “a” and “b” (or “c”) at two different points A and B obtained by the light amount distribution measurement unit 3. Accordingly, even when the position of the light emitting point of the semiconductor laser 11 to be measured is shifted, only the information on the light emitting angle θ can be obtained independently, so that the light emitting angle θ of the semiconductor laser 11 can be accurately measured. it can.

That is, a straight line M (or M ') connecting the corresponding measurement points S, T (or U) on the light quantity distribution "a", "b" (or "c") at the two points A and B. ), The information on the emission angle θ alone can be obtained independently of the displacement in the y direction when the submount 10 is chucked, and the emission angle θ of the semiconductor laser 11 can be accurately measured. can do.

In the light emitting angle measuring apparatus 1 described above, the case has been described where the light quantity distribution measuring section 3 is provided so that the light receiving section 5 is movable on the carrier section 4. The unit 3 may be configured so that a plurality of sets of light receiving units 5 are provided on the carrier unit 4 in a state of being fixed in an array. In this case, since the light amount distribution from the semiconductor laser 11 can be obtained at once, the light amount distribution can be measured quickly.

[0029]

As described in detail above, according to the first to third aspects of the present invention, the light emission angle of the light source with respect to the reference plane is calculated based on the light quantity distribution at two different points. Even when the position of the light emitting point of the light source to be measured is shifted, only the information on the light emitting angle can be obtained independently.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a configuration of a light emission angle measuring device of a light source for an optical pickup according to an embodiment of the present invention.

FIG. 2 is a functional block diagram illustrating a configuration of a light emission angle calculation unit.

FIG. 3 is a diagram for explaining an emission angle of a semiconductor laser.

FIG. 4 is a flowchart showing an operation procedure in the light-emitting angle measuring device of the light source for the optical pickup according to the embodiment of the present invention.

[Description of Signs] 1 Emission Angle Measurement Device 2 Pressing Member 3 Light Amount Distribution Measurement Unit 4 Carrier Unit 5 Light Receiving Unit 5A Slit 5B Holding Member 6 Emission Angle Calculation Unit 7 Power Supply 8 Guide Member 10 Submount (Mount Member) 11 Semiconductor Laser (Light source for optical pickup) 12 Display unit 13 Printing unit 14 Data storage area 14A First data storage unit 14B Second data storage unit 15 Measurement point detection unit 16 Angle calculation unit P1 Reference surface Q1 Contact surface

Claims (3)

[Claims] 1. An apparatus for measuring a light emission angle of a light source for an optical pickup mounted on a mount member having a required reference surface with respect to the reference surface, the device being adapted to press the reference surface of the mount member. A pressing member having a contact surface; a light amount distribution measuring unit capable of measuring a light amount distribution from the light source by moving along a light emitting direction of the light source behind the pressing member; An optical pickup for an optical pickup, comprising: a light emission angle calculation unit that calculates a light emission angle of the light source with respect to the reference plane based on the light amount distribution at two different points obtained by the distribution measurement unit. Emission angle measuring device for light source. 2. The light quantity distribution measuring section is provided on the carrier section so as to be able to move linearly behind the pressing member, and on the carrier section so as to be able to move in a direction intersecting the moving direction of the carrier section. 2. The light-emitting angle measuring device for a light source for an optical pickup according to claim 1, further comprising a light receiving portion having a slit. 3. When measuring an emission angle of the light source for an optical pickup mounted on a mount member having a required reference surface with respect to the reference surface, the reference surface of the mount member is pressed against a predetermined contact surface. In this state, after measuring the light amount distribution at two points having different distances from the reference plane along the light emitting direction of the light source, the corresponding measurement points on the light amount distribution at these two points are used to determine the light source distribution of the light source. A method for measuring a light emission angle of a light source for an optical pickup, wherein a light emission angle with respect to a reference plane is obtained.