JPH0612679A - Method for adjusting light pickup - Google Patents

Abstract

PURPOSE:To accurately adjust an light pickup optical system which constitutes of a semiconductor and a photodetector on a supporting body and employs a reflection hologram by rotation adjustment. CONSTITUTION:An optical disk 4 is mounted on an objective lens and a microscope 2 is mounted on the disk. Adjustment is executed while making a converged spot comes always on an optical axis at the time of rotation adjustment. The optical disk 4 is mounted on a movable coil part for adjusting the optical system using an SSD focusing method, and the adjustment is executed so that a groove traverse signal becomes minimum while applying focus servo to the movable coil part. Thus, the optical pickup optical system using the reflection type hologram is adjusted accurately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field in which a small-sized optical pickup using a hologram is required, and particularly to an electric device using an optical pickup such as an optical disc and a compact disc (hereinafter abbreviated as CD). The present invention relates to an optical pickup adjustment method for adjusting an optical pickup so that control and tracking control can be optimally performed.

[0002]

2. Description of the Related Art An optical pickup using a hologram grating has a simple optical system, and as a result, downsizing, weight saving and cost reduction are possible, and it has been partially put into practical use. In particular, as a focus detection method, a spot size detection method (hereinafter referred to as SSD method) that uses a difference between two spot diameters is used, and a method of detecting using a parallel-divided optical system as a photodetector arrangement, a combination error thereof is used. Is acceptable up to about 200 μm, so it is considered to be a method with excellent mass productivity. This will be described with reference to FIGS. 5 and 6 (Proc.Int.on Op
tical Memory, 1989; Japanese Journal of Applied Phi
sics, Vol. 28 (1989) Supplement 28-3, pp. 189-192).

In these figures, the photodetector 9 which is a light receiving element and the semiconductor laser 8 which is a light source are approximately 1
It is installed as shown in the figure on a copper block 10 of mm cube. Now, let us consider the installation error between the photodetector 9 and the semiconductor laser 8 which is the largest as a cause of the assembly error. Now, the photodetector 9 is arranged on the copper block 10 at the position of the reference numeral 9a. The ideal position of the semiconductor laser 8 with respect to the position of the reference numeral 9a of the photodetector 9 is on the center line 41 running in the middle of the focus signal detecting portions 22a and 22b for SSD spot detection and the tracking signal detecting portions 24a and 24b. Consider the case where the position of the code 8a is the ideal position, but actually it is at the position of the code 8b deviated from the position by the distance e. Now the semiconductor laser 8 at the position of reference numeral 8a
The light emitted from is reflected and bent by the reflection hologram 5, as shown in FIG. The bent light is focused on the optical disc 4 by the objective lens 7. The condensed light, that is, the light spot is reflected by the optical disc 4 and returned to the reflection hologram 5. An enlarged view of the reflection hologram 5 is shown in FIG. The tracking part grating for separating the light for generating the tracking signal is the area indicated by reference numerals 27a and 27b. Further, the focus part grating part that generates the focus signal is the region indicated by reference numerals 28a and 28b. The light separated by the tracking unit grating 27a becomes a tracking light spot 23a on the photodetector 9. Similarly, the light separated by the tracking section grating 27b becomes a tracking light spot 23b, and the light separated by the focus section grating 28a becomes a focus light spot 21a, which is separated by the focus section grating 18b. The focused light becomes a focusing light spot 21b.

Now, the grating 28 for the focus section
Since a and 28b have a weak curvature, they have a lens effect. Now, the grating 28 for the focus section
a is a positive curvature, that is, a condensing point is formed in front of the photodetector 9. On the contrary, the focusing portion grating 28b is provided with a negative curvature so that a converging point is generated behind the photodetector 9. Of course, when no curvature is given, two light spots are formed on the photodetector 9 if the light emitting surface of the semiconductor laser 8 and the light receiving surface of the photodetector 9 are on the same surface.

The optical barrel 19 has one opening end face orthogonal to the central axis and the other opening end face inclined approximately 45 degrees with respect to the central axis, and is close to the other opening. Then, an opening for attaching an objective lens is provided in the peripheral cylinder. The copper block 1 is provided on one opening end surface of the optical barrel 19.
The support body 6a with 0 attached is attached so as to be rotatable within one opening end face. In addition, a support 6b to which the reflection hologram 5 is fixed is rotatably attached to the other opening end of the optical lens barrel 19 within the other opening end face of the optical lens barrel 19. Reference numeral 26 is a movable part in which the optical barrel 19 and the supports 6a and 6b are integrated, and is moved up and down or left and right by the driving coil 25 to perform focus adjustment or tracking adjustment.

As described above, when the optical disk 4 is at the image forming position of the semiconductor laser 8, the focus points of the focusing light spots 21a and 21b are evenly displaced to the positions in front of and behind the photodetector 9, respectively. Since they exist, they have the same spot diameter on the surface of the photodetector 9. Now, as a feature of such a system, the image forming point with respect to the emission position of the semiconductor laser 8 is the difference in the position designed by the reflection hologram 5 from the semiconductor laser 8 regardless of the optical path in the middle except for the aberration. The image forming point is located at a distance (d in the case of FIG. 5).

Now, when the setting of the reflection hologram 5 is rotated from a predetermined angle, even if the semiconductor laser 8 is at the ideal position 8a, the light spot array 2 as shown in FIG.
1a, 21b, 23a, 23b are formed. Therefore, in this example, description will be added only when the position of the semiconductor laser 8 is deviated from the ideal position.

Although such an optical system is stable, it is necessary to delicately set the positional relationship between the semiconductor laser 8 as a light source and the photodetector 9. Therefore, conventionally, if the position of the semiconductor laser 8 is deviated from the ideal position, as shown in FIG. 5, by rotating the support 6a for supporting the photodetector 9 and the semiconductor laser 8 with a jig, as shown in FIG. Light spot rows 21a, 21b,
By disposing 23a and 23b and the photodetector 9, it becomes possible to correct the deviation of the semiconductor laser 8 from the ideal position.

Further, as described above, even if the semiconductor laser 8 is located at the ideal position 8a, the light spot rows 21a, 21b, 23a and 23b are as shown in FIG. It is possible to normalize the positional relationship between the light spot rows 21a, 21b, 23a, 23b and the photodetector 9 by rotating the support 6a that supports the semiconductor laser 8 and the semiconductor laser 8 or the reflection hologram 5. Is.

[0010]

Using this principle, adjustment of an optical system has been conventionally performed. The biggest drawback in this case is that it is not clear what the relationship between the position of the semiconductor laser 8 as the light source and the rotation center of the support 6a is. Normally, the semiconductor laser 8 is rarely located at the center of rotation of the support 6a. In this case, by rotating the support 6a, the semiconductor laser 8 itself, which is the light source, also moves. The biggest problem caused by the movement of the semiconductor laser 8 is that the semiconductor laser 8 deviates from the center of the optical axis. In the normal objective lens 7 for an optical pickup, the allowable distance from the center of the optical axis is about 100 μm at most when the inclination of the optical disc 4 is taken into consideration. It is considered that this 100 μm or so is easily generated when the center of the rotation axis and the center of the optical axis are not located.

Further, when the reflection hologram 5 is rotated to make this correction, this problem becomes more important. Here, consider the case where the reflection hologram 5 is rotated in the optical system shown in FIG. In order to rotate this, it is naturally necessary to separate the reflection hologram 5 from the optical barrel 19 by a slight amount. It is assumed that the distance is about 20 μm. Now, assume that the reflection hologram 5 has a diameter of 2 mm. At this time, the mirror will be tilted up to 0.02 / 1 = 0.02Rad = 1.15 degrees.

At this time, if the distance between the reflection hologram 5 and the semiconductor laser 8 is about 10 mm, an image height of 0.02 × 10 = 0.2 mm = 200 μm is generated only by the occurrence of this inclination. It will be. Therefore, as long as the structure is such that only ideal rotation is given as has been conventionally considered, in actuality, not only when the semiconductor laser 8 is rotated, but also when the reflection hologram 5 is rotated and adjusted,
Image height was generated, and it was difficult to make ideal adjustments.

On the other hand, let us consider a case where the optical pickup is driven integrally, especially for the purpose of downsizing. In this case, as a method for adjusting the optical system, in particular, it is impossible to perform the adjustment by rotating an optical disk which has been conventionally made, as in normal reproduction. in this case,
A support 6a or a reflection member that supports the semiconductor laser 8 and the photodetector 9 so that the focus signal and the tracking signal are optimized while the disk piece is placed on the fine movement table and finely moved in the vertical direction (focus direction) and the horizontal direction (tracking direction). The support 6b that supports the mold hologram 5 is rotationally adjusted. But in this case
In order to obtain the best tracking signal, the disk piece needs to have a track signal detecting groove. On the other hand, if there is a track signal groove to detect the focus signal,
Since the reflectance is remarkably different depending on whether the focused spot by the objective lens is on the groove or not, it is difficult to accurately determine the best point of the focus signal due to the existence of the track groove.

Therefore, an object of the present invention is to provide an optical pickup adjusting method capable of easily and accurately determining the best point of a focus signal.

[0015]

According to another aspect of the present invention, there is provided an optical pickup adjusting method, wherein a semiconductor laser serving as a light source and a light receiving element are arranged on a rotatable first support, and the semiconductor laser is adjusted. The emitted light is reflected by the reflection hologram disposed on the rotatable second support, then focused to the diffraction limit by the objective lens, and irradiated as a light spot on the optical disc. The reflected light from the reflection type hologram is reflected by the reflection type hologram, and at this time, the reflected light is separated into tracking signal light and focus signal light and enters the light receiving element, and is converted into an electric signal by the light receiving element. An optical pickup adjustment method for optimally adjusting the focus signal.

Therefore, an image of the focal point by the objective lens is formed by the imaging optical system arranged on the side of the optical disc opposite to the objective lens, and the position of the image of the focal point does not move. While the first support is being moved, the rotation of at least one of the first and second supports is adjusted so that the focus signal swings when the optical disc is moved in the focus direction. Adjust to maximize.

An optical pickup adjusting method according to a second aspect is an optical pickup adjusting method for optimally adjusting a focus signal as in the first aspect, wherein the optical disc has a flat first reflecting surface at a part thereof. Then, an optical disc having a second reflecting surface having a track groove in the other portion is prepared, the optical disc is placed on a fine movement table movable in the focus direction and the tracking direction, and the fine movement table is operated to operate the first optical disc. The optical disk is positioned in a state where the light spot is irradiated on the reflection surface of the optical disk, and an image of a focal point by the objective lens is formed by an imaging optical system arranged on the opposite side of the optical disk from the objective lens. , And at least one of the first and second supports while moving the first support so that the position of the image of the focal point does not move. The optical disc is adjusted by adjusting the rotation so that the shake of the focus signal when moving the optical disc in the focus direction becomes maximum, and then supplying the focus signal to the drive unit of the fine movement table. Is controlled in such a way that the distance between the objective lens and the optical disk is constant, and the fine moving table is operated to irradiate the light spot on the second reflecting surface. In the tracking direction to drive the optical disc so that the light spot traverses the track groove on the second reflecting surface, and the first support body is configured to minimize the deflection of the focus signal. Adjust the rotation.

[0018]

The principle of the present invention will be described in detail with reference to FIGS. First, the support 6a for supporting the semiconductor laser 8 and the photodetector 9 or the reflection hologram 5
When the support body 6b that supports the optical axis is rotated, the rotation centers of the support bodies 6a and 6b do not normally coincide with the optical axis center 31. Therefore, if this is adjusted by rotation adjustment using a jig, the optical axis The positions of the center 29 and the semiconductor laser 8 are out of order. In order to prevent this, the transmittance of the optical disk 4 is made very small, and the transmitted light 30 is imaged by the microscope lens 3 (corresponding to the imaging optical system in the claims). The support 6a or 6b is rotated clockwise or counterclockwise around the rotation shaft 12a or 12b while observing this image formation (focused spot 31). At this time, the positions of the optical axis center 29 and the focused spot 31 deviate from each other for the reason described above. At this time, the support 6a
By linearly moving in the direction of the arrow 32a or in the direction of the arrow 33a orthogonal thereto, the center 29 of the optical axis and the focused spot 31 can be aligned again. By doing so, it becomes possible to remove the optical axis shift caused by the rotation adjustment. In this state, the focus signal 37 (see FIG. 4) is adjusted optimally. In this case, the optical disc 4 is moved in the tracking direction 15
The focus signal 37 is fixed and is adjusted so that the shake of the focus signal 37 is maximized when the optical disc 4 is moved only in the focus direction 14 with the focused spot 31 positioned on the plane portion of the optical disc 4.

In the rough adjustment of the focus signal 37, it is necessary that the optical disc 4 has no signal groove as described above. However, in order to optimize the focus signal 37, it is necessary to further reduce the groove crossing signal due to the signal groove. In this case, first, the support 6a that supports the semiconductor laser 8 and the photodetector 9 or the support 6b that supports the reflection hologram 5 is rotated so that the focus signal 37 becomes the best in the portion of the optical disc 4 where there is no signal groove. adjust. At this time, the adjustment is performed so that the shake of the focus signal 37 becomes maximum when the optical disc 4 is moved in the focus direction 14.

Next, the focus signal detector 22
By applying the focus signals 20 and 21 from a and 22b to the movable coil 17, the distance between the optical disk 4 and the objective lens 7 can be kept constant. After that, the support rod 18 or the optical barrel 19 is moved to move the optical disc 4
Move it to the groove. Then, a low-frequency voltage is applied to the tracking moving coil 34, and this time the moving coil portion (1
7, 34) in the tracking direction 15. As a result, the light spot crosses the track groove portion, and the groove crossing signal 35 (see FIG. 4) is added to the focus signal.
Occurs. While observing such a state with the oscilloscope 38, the support 6a or the support 6b is further rotated and adjusted so that the groove crossing signal 35 is minimized.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIG. 1, and the present invention will be described in detail. In the case of the embodiment of the present invention, an explanation will be given by using an adjustment example of an integrated drive type optical pickup optical system. An example of an integrated drive type optical pickup is shown in FIG. In the case of the integrated drive type as in this example, the semiconductor laser 8, the photodetector 9 for receiving light, the reflection hologram 5 and the objective lens 7 are incorporated into one optical barrel 19, and this optical barrel 19 is a driving coil. It is moved in the focus direction 14 and the tracking direction 15 (not shown in FIG. 6 and indicated by reference numeral 25 in FIG. 6), whereby the signal groove on the optical disk 4 can be accurately tracked, and the signal groove on the optical disk 4 is moved. It is possible to accurately read the engraved signal.

On the other hand, as another method, there is an optical pickup in which only the objective lens 7 is made to follow the groove of the optical disc 4. Such an optical pickup is called a lens drive type optical pickup. But reflective hologram 5
Since the same adjustment method is required in any of the cases described above, an integral drive type optical pickup, particularly spot size detection (hereinafter referred to as SSD method) as a focus signal detection method will be described in this description. The one used will be described, but the same applies to the case of an optical system using an optical pickup optical system configured by adopting the three-beam method as another tracking signal method and the SSD method as a focus signal detection method. .

In the case of the above embodiment, the optical barrel 19 is installed on the lower side of the optical disk 4, and the completely fixed microscope 2 is installed on the upper side of the optical disk 4 on the opposite side. The image created by this microscope 2 is the CCD camera 1
Is converted into an electric signal and displayed on the TV monitor 11. An enlarged image of this image is shown in FIG. As shown in FIG. 2, what is displayed on the screen is a mere focused spot 31. In particular, the reason why the CCD camera 1 is used is that the semiconductor laser 8 usually used as an optical pickup light source has an emission wavelength of about 790 nm, and the light is invisible.

First, a method of determining the optical axis center 29 in the microscope 2 will be described. First, the optical disc 4 is moved sufficiently in the tracking direction 15 so that the periphery of the objective lens 7 can be completely seen by the microscope 2. In this case, the center of the peripheral circle of the objective lens 7 becomes the optical axis center 29. However, depending on the magnification of the microscope lens 3, there are cases where the entire lens circumference 13 of the objective lens 7 cannot be seen. In such a case, the circumference center, that is, the optical axis center 29 is determined from the scale attached to the fine movement table or the like. can do. After the optical axis center 29 is determined in this way, the tracking direction 15 is again set.
The optical disk 4 is pulled back to. In this case, since the optical disc 4 is interposed between the microscope 2 and the objective lens 7, the lens circumference 13 can no longer be observed. Next, a current is applied to the semiconductor laser 8 to cause the semiconductor laser 8 to emit light. The light emitted from the semiconductor laser 8 is condensed by the objective lens 7. This condensed image can be formed on the CCD camera 1 by moving the microscope 2 up and down. Now this focused spot 31 and the optical axis center 2
If 9 does not match, they can be matched by moving the support 6a in the direction of the arrow 32a or the arrow 33a.

The semiconductor laser 8 and the photodetector 9 shown by FIG. 2 are not visible through the optical disc 4, but in essence what they appear to be. Therefore, as can be easily understood from this figure, it can be easily understood that when the support 6a is rotated in the rotation direction shown by the arrow 12c, the focused spot 31 moves. Therefore, when adjusting by the rotation method when using the SSD method, the support 6a is moved while moving the support 6a in the directions of the arrows 32a and 33a so that the focused spot 31 is constantly located at the optical axis center 29. By rotating with a jig, the deviation of the focused spot 31 from the optical axis center 29 can be corrected. Now, when the focused spot 31 is displaced from the optical axis center 29 when the support 6a is rotated, for example, the support 6a may be moved in the direction of the arrow 32a or the arrow 33a so as to cancel it. Easy to understand.

On the other hand, also when the support 6b for supporting the reflection hologram 5 is rotated, the focused spot 31 can be moved to the optical axis center 29 by moving the support 6a in the same manner. . As described in the conventional example, when the reflection hologram 32 is rotated for adjustment, the focus spot 31 moves because the inclination of the reflection hologram 5 changes. Therefore, in order to correct this, it is sufficient to add the tilt of the reflection hologram 5 in a direction to correct the tilt change caused by the rotation, or move the support 6a as described above, and thereby, the reflection hologram. It is possible to easily correct the displacement of the position of the focused spot 31 due to the slightest change in the inclination angle of 5.

Therefore, when the present invention is used, the focused spot 31 generated by rotating the support 6a supporting the semiconductor laser 8 and the photodetector 9 or the support 6b supporting the reflection hologram 5 and the optical axis center. By correcting the deviation of 29 by linearly moving the support 6a, it is possible to accurately adjust the rotation of the focus signal 37 to the best level.

The above description of the first embodiment corresponds to the contents of claim 1, and the following description of the second embodiment corresponds to claims 2 and 3. By the way, according to the present invention, it is possible to adjust the focusing signal to be the best while arranging the focused spot 31 on the optical axis center 29, but this does not mean that the adjustment by the SSD method is all completed. This will be described in detail with reference to FIGS. 3 and 4.

When the SSD method is used to detect the focus signal, as described above, the support 6a or the support 6a or the support 6a is used so that the amplitude of the focus signal 37 shown in FIG. Rotate 6b. The optical barrel 19 adjusted in this way is arranged as shown in FIG. In this case, the optical disk 4 is attached to the movable coil portion including the tracking movable coil 34 and the focus movable coil 17. The tracking movable coil 34 and the focus movable coil 17
The movable coil portion made of is fixed to the support rod 18 by a spring 39 or the like, and the optical disk 4 can be moved in the tracking direction 15 and the focus direction 14 by the current flowing in the tracking movable coil 34 and the focus movable coil 17. . The above structure constitutes the fine movement table in the claims. 16 is a permanent magnet.

In the optical barrel 19, the support 6a is adjusted so that the focus signal 37 shown in FIG. 4 is output as described above. Therefore, based on this focus signal 37, a current is supplied to the movable focus coil 17. Is flowed, the distance between the optical disk 4 and the objective lens 7 is kept constant. In this case, the signal state of the focus signal 37 in FIG. 4 can be confirmed by inputting the focus detection signals 20 and 21 in FIG. 3 to the oscilloscope 38.

In FIG. 4, the horizontal axis represents the distance between the optical disk 4 and the objective lens 7. The vertical axis represents the voltage generated in the photodetector 9 at this time. At this time, when the focus signals 20 and 21 are connected to the movable coil section, the focus movable coil 17 continuously outputs the focus signal 37 (20, 2).
1) is 0 volt, that is, the movable focus coil 17 moves in the focus direction 14 so that the objective lens 7 and the optical disc 4 have a constant spacing, so that the distance between the optical disc 4 and the objective lens 7 is kept constant. Be done. In this way, when the light is focused on the optical disk 4, the voltage is also applied to the tracking movable coil 34 to move the tracking movable coil 34 in the tracking direction 15, thereby moving the optical disk 4 in the tracking direction. It becomes possible to move the optical spot to the optical disk 4 by moving the optical spot to the optical disk 4 from the state in which the flat light reflecting surface 4a of the optical disc 4 is irradiated to the reflective surface 4b having a continuous track groove. The light spot will cross. The focus signal generated at this time is the groove crossing signal 35 in FIG. In the case of the adjustment up to this point, a wavy signal corresponding to crossing the track groove usually appears in the focus signal. This is because when a focus signal is detected by the SSD method, if there is a very slight displacement on the photodetector 9 or if there is an imbalance in the photodetector 9, such a groove crossing signal 35
Appears. Such a groove crossing signal 35 causes a focus error. That is, although the positional relationship between the optical disc 4 and the objective lens 7 must be constant, the focus signal changes in the state of the track groove, that is, the distance between the optical disc 4 and the objective lens 7 varies slightly. Therefore, when the optical disc 4 is read, the fluctuation component is added to the read signal, so that it is not a good signal. Therefore, in the embodiment of the present invention, the support 6a is rotated very slightly while detecting such a signal, and the support 6a is further rotated slightly so as to make the groove crossing signal 35 as close to 0 as possible. Done. Figure 4
The curve indicated by reference numeral 36 represents the focus signal after the groove crossing signal appearing in the focus signal when the light spot crosses the track groove is adjusted to be as close to 0 as possible.

[0032]

According to the optical pickup adjusting method of the first aspect of the present invention, the semiconductor laser and the light receiving element are provided.
It is possible to correct the deviation of the focused spot from the center of the optical axis caused by the rotation adjustment of at least one of the support and the second support provided with the reflection hologram, and the focus adjustment of the optical pickup can be performed. Can be performed with high accuracy, and an optical pickup having excellent characteristics can be manufactured. Therefore, the accuracy required for the first support provided with the semiconductor laser and the light receiving element can be reduced, and the cost can be reduced.

According to the optical pickup adjusting method of the second aspect, it is possible to perform more detailed focus adjustment when the SSD method is used for detecting the focus signal. When this method is used, it is possible to make adjustments without rotating the optical disc and without moving the optical pickup, so detailed and stable adjustments can be made for both the integrated drive optical pickup and the lens drive. It becomes possible to do.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of an optical pickup adjusting method of the present invention.

FIG. 2 is a schematic diagram showing an example of a microscope image in the first embodiment.

FIG. 3 is a schematic view showing a second embodiment of the optical pickup adjusting method of the present invention.

FIG. 4 is a waveform diagram showing a focus signal image by an oscilloscope.

FIG. 5 is a schematic view showing a positional relationship between a semiconductor laser and a photodetector and a light spot.

FIG. 6 is a schematic view of an integrated drive type optical pickup.

FIG. 7 is a schematic diagram showing an example of a reflection hologram.

[Explanation of symbols]

 1 CCD Camera 2 Microscope 3 Microscope Lens 4 Optical Disc 5 Reflective Hologram 6a, 6b Support 7 Objective Lens 8 Semiconductor Laser 9 Photodetector 10 Copper Block 11 TV Monitor 12a, 12b Rotation Axis 13 Lens Circle 14 Focus Direction 15 Tracking Direction 16 Magnet 17 Focus movable coil 18 Support rod 19 Optical lens barrel 20 21 Focus signal 22a 22b Focus spot 23a 23b Tracking spot 24a 24b Tracking signal detector 25 Drive coil 26 Moveable part 27a 27b Tracking part grating 28a 28b Focus part grating 29 Optical axis center 30 Transmitted light 31 Focused spot 34 Tracking movable coil 35 Groove crossing signal 38 Oscilloscope

Claims (3)

[Claims] 1. A second support body in which a semiconductor laser as a light source and a light receiving element are arranged on a rotatable first support body, and light emitted from the semiconductor laser is rotatable. After being reflected by the reflection hologram arranged above, it is condensed to the diffraction limit by the objective lens and irradiated as a light spot on the optical disc, and the reflected light from the optical disc is reflected by the reflection hologram. An optical pickup adjusting method for optimally adjusting the focus signal of an optical pickup in which reflected light is separated into tracking signal light and focus signal light, enters the light receiving element, and is converted into an electric signal by the light receiving element. Wherein an image of a focal point by the objective lens is formed by an imaging optical system arranged on the opposite side of the optical disc from the objective lens, and The optical disk for focus adjustment by adjusting the rotation of at least one of the first support and the second support while moving the first support so that the position of the image of the focal point is not moved. A method for adjusting an optical pickup, wherein the shake of the focus signal is maximized when the lens is moved in the focus direction. 2. A second support body in which a semiconductor laser serving as a light source and a light receiving element are arranged on a rotatable first support body, and light emitted from the semiconductor laser is rotatable. After being reflected by the reflection hologram arranged above, it is condensed to the diffraction limit by the objective lens and irradiated as a light spot on the optical disc, and the reflected light from the optical disc is reflected by the reflection hologram. An optical pickup adjusting method for optimally adjusting the focus signal of an optical pickup in which reflected light is separated into tracking signal light and focus signal light, enters the light receiving element, and is converted into an electric signal by the light receiving element. And preparing an optical disc having a second reflective surface having a flat first reflective surface in one part and a track groove in another part, Of the optical disk of the objective lens (hereinafter, referred to as a focus direction) and a direction (hereinafter, referred to as a tracking direction) orthogonal to the optical lens are mounted on a fine movement table, and the fine movement table is operated to operate the fine movement table. The optical disc is positioned so that the light spot is irradiated on the reflection surface of No. 1, and an image of a focal point by the objective lens is formed by an imaging optical system arranged on the opposite side of the optical disc from the objective lens. In addition, while rotating the first support so that the position of the image of the condensing point does not move, at least one of the first support and the second support is rotationally adjusted to obtain the optical disc. Is adjusted so as to maximize the shake of the focus signal when the focus signal is moved in the focus direction, and then the focus signal is supplied to the drive unit of the fine movement table to adjust the optical signal. The disk is driven in the focus direction to control the distance between the objective lens and the optical disk to be constant, and the fine movement table is operated to set the second reflection surface to the state where the light spot is irradiated. The optical disc is moved in the tracking direction, and the second
While rotating the optical disk so that the light spot traverses the track groove on the reflective surface of the optical disk, the first support is rotationally adjusted so that the shake of the focus signal is minimized. Pickup adjustment method. 3. The optical pickup adjusting method according to claim 1, wherein the focus signal is detected based on a difference in size of spot shapes on the photodetector.