JP5476201B2 - Pickup device lens and method for inspecting the lens - Google Patents

Description

  The present invention relates to a lens for a pickup device and a method for inspecting the lens.

  A pickup device is used to read information from an optical disk or record information on an optical disk. The pickup device has a lens for condensing a light beam for reading or writing on an optical disk.

  In general, the lens is fixed to the holder of the pickup device with an adhesive. In fixing the lens to the holder of the pickup device, it is necessary to accurately position the lens so that the optical axis of the lens matches the optical axis of the optical member positioned on the light source side with respect to the lens. In order to position the lens with respect to the holder, it is necessary to detect the tilt of the lens. In order to detect the inclination of the lens, for example, a detection device described in Patent Document 1 is used.

  The detection device described in Patent Document 1 uses an edge reflection surface formed on a lens. The edge reflecting surface is a flat surface portion formed on one surface of a flange portion provided around the lens surface of the lens and perpendicular to the optical axis of the lens. The detection device for detecting the tilt of the lens is configured to reflect light parallel to the lens optical axis when the lens is accurately positioned at the edge reflecting surface of the lens and to make the return light enter the imaging lens. . An imaging camera is disposed at the focal position of the imaging lens. The imaging lens and the imaging camera are positioned such that when the lens is accurately positioned, a spot due to light from the imaging lens is displayed at a specific position in the image captured by the imaging camera. Therefore, when the lens is tilted from the position where it should be originally mounted, a spot is displayed at a position shifted from the specific position according to the direction and degree of tilt. Therefore, the direction and degree of lens tilt can be detected from the position of the spot in the image captured by the imaging camera.

Japanese Patent No. 3393039

  A lens used in a pickup device is a resin molded product that is generally molded by injection molding. That is, the lens is provided as a lens molded product integrated with the sprue and the gate at the time of molding, and the lens is separated from the lens molded body by cutting the gate in a later process. For this reason, a part of the gate is left in the lens, or a part of the lens is cut to completely remove the gate. In general, since the gate is formed on the cylindrical surface of the flange portion of the lens, a gate mark such as a part of the gate or the cutting portion is formed on the cylindrical surface of the lens flange portion. It will be.

  Since the lens for the pickup device is molded by injection molding, there is a possibility that a refractive index bias or directivity based on the flow direction of the resin during molding may occur. Therefore, it is desirable to position the lens with respect to the holder so that the gate traces are directed in a predetermined direction so as to minimize the influence of the refractive index bias and directivity. For example, a lens molded by resin molding may cause astigmatism, and in order to minimize the influence of the astigmatism in information reading or the like, the gate mark is in the radial direction of the optical disk. It is desirable to position the lens on the holder of the pickup device so that it is located in the middle of the tangential direction (that is, the gate mark is disposed at a position inclined about 45 ° from the radial direction).

  Further, coma aberration occurs and remains in these lenses at the time of molding. This coma aberration is measured after being set in the measuring device so that the gate trace of the lens faces a predetermined direction. That is, the measured coma aberration direction is based on the direction from the optical axis of the lens to the gate mark (that is, the coma aberration direction is defined as a relative angle with respect to the direction from the optical axis to the gate mark. Is). The coma aberration is compensated by an actuator inclination adjusting mechanism or the like that is separately attached to the pickup device. In order to compensate for the coma aberration, the direction of the coma aberration on the holder needs to be known. For this purpose, the lens is mounted in a predetermined direction with respect to the gate direction. Thus, in order to compensate for coma, it is desirable that the lens be attached to the holder so that the gate faces a predetermined direction.

  SUMMARY OF THE INVENTION In view of the above problems, the present invention is directed to a pickup device lens and lens holder capable of detecting the direction of the gate trace of the lens with the optical axis of the lens as the origin and positioning the gate trace at a desired position of the holder of the pickup device. An object of the present invention is to provide a method for inspecting a lens for positioning the lens.

  In order to achieve the above object, the lens for the pickup device of the present invention is configured such that incident light that is incident on the first lens surface side of the flange portion is inclined with respect to the optical axis of the lens and is parallel to the optical axis. Is formed on a circumference centering on the optical axis of the lens. A gate mark region that does not reflect incident light incident in parallel to the optical axis in the reflection direction is formed at a predetermined position with respect to the gate trace of the lens in the circumferential direction on the circumference.

  Parallel light is incident on the first lens surface side of the lens having the above-described configuration, reflected light reflected on the first lens surface side surface of the flange portion of the lens is incident on the imaging lens, and an image formed by the reflected light is obtained. An image of the reflected light reflected by the first lens surface side surface of the flange portion of the lens imaged by the imaging means disposed at the imaging position of the imaging lens is displayed on the monitor screen. When displayed, the light reflected by the edge reflecting slope portion becomes an image (light spot, halo, etc.) having a predetermined shape. In addition, the gate mark region (for example, a surface that does not reflect light or a surface that reflects light in a direction different from the edge reflection slope) has a characteristic shape in the image reflected by the edge reflection slope. Add a part (for example, a notch formed in the halo). The position of the characteristic shape portion is determined by the position of the gate mark region with respect to the gate mark. The gate mark area is formed at a predetermined position with respect to the gate mark of the lens (that is, the position of the gate mark area with respect to the gate mark is known). Therefore, the direction of the gate mark relative to the optical axis, that is, the rotation angle around the optical axis of the lens can be determined from the position of the characteristic shape portion.

  Further, an edge reflection plane portion that is a plane perpendicular to the optical axis of the lens surface may be formed on the surface of the flange portion on the first lens surface side.

  The parallel light is incident on the first lens surface side of the lens having such a configuration, the reflected light reflected by the first lens surface side surface of the flange portion of the lens is incident on the imaging lens, and an image by the reflected light is input. Is picked up by the image pickup means arranged at the image forming position of the image forming lens, and an image of the reflected light reflected by the first lens surface side surface of the flange portion of the lens picked up by the image pickup means is displayed on the monitor screen. In this case, the light incident on the edge reflection plane portion is shown as a light spot on the monitor screen. And the direction with respect to the optical axis of a gate mark can be discriminate | determined from the relative position with respect to the said light spot of the image by the light which injected into the edge reflective slope part.

  The flange portion is formed with a conical surface centered on the optical axis of the lens, and the gate mark region is formed over the entire radial direction of a portion of the conical surface. It is good also as a structure by which the edge reflection slope part is formed in parts other than a mark area | region.

  With such a configuration, the image on the screen of the monitor by the light incident on the edge reflecting slope portion is an annular image in which a characteristic shape (notch or the like) appears in a portion corresponding to the gate mark region. Therefore, in which direction the gate mark area is located with respect to the optical axis of the lens, based on the relative position between the light spot reflected by the edge reflection plane and the image reflected by the edge reflection slope. Thus, the direction of the gate mark relative to the optical axis, that is, the rotation angle around the optical axis of the lens can be determined.

  In particular, when the gate mark region is formed at a position close to the gate trace of the lens, it is characteristic in the image of the light spot reflected by the edge reflection plane part and the light reflected by the edge reflection slope part. The relative position with the shape portion indicates the position and direction of the gate mark with respect to the optical axis.

  Further, the gate mark region is, for example, a non-reflective portion that does not substantially reflect light incident on the gate mark region.

  Moreover, it is good also as a structure where the edge reflection slope part is a planar slope formed in multiple numbers along the periphery in which the edge reflection slope part was provided.

  With such a configuration, the light reflected by the plurality of edge reflection slopes is displayed on the monitor screen at different positions on the circumference around the light spot by the light reflected by the edge reflection flat part. It becomes a light spot. Then, from the relative position of the light spot reflected by the edge reflection plane part and the plurality of light spots reflected by the edge reflection slope part, the position of the gate trace relative to the optical axis, that is, the rotation angle around the optical axis of the lens Can be determined.

  Here, the plurality of edge reflection slope portions are formed at positions shifted by a predetermined angle around the optical axis of the lens from the position close to the lens gate trace on the circumference where the edge reflection slope portion is provided. The gate mark region reflects incident light parallel to the optical axis in a direction other than the reflection direction, which is formed at a position where the edge reflection slope portion is not formed, including a position close to the gate trace of the lens. It is preferable to adopt a configuration that is a portion to be used.

  With such a configuration, on the monitor screen, the plurality of light spots reflected by the edge reflection slope portion are on the vertices of a regular polygon centered on the light spot reflected by the edge reflection plane portion. The direction of the vertex of the regular polygon where the light spot is not displayed among the vertices of the regular polygon with respect to the light spot by the light reflected by the edge reflection plane portion indicates the position and direction of the gate trace of the lens. It will be.

  Further, the gate mark region is, for example, a flat portion perpendicular to the optical axis of the lens.

  Moreover, it is preferable that the edge reflection slope portion is an inward slope whose reflection direction is the direction toward the optical axis. In this configuration, the image of the edge reflection slope portion becomes a normal image of the edge reflection slope portion, and therefore it is easy to adjust the position of the lens.

  Alternatively, the edge reflection slope portion may be an outward slope whose reflection direction is away from the optical axis.

  The first lens surface is a lens surface located on the optical disc side where information is read or recorded by the pickup device.

  In the lens inspection method of the present invention, parallel light is incident on the first lens surface side of any one of the above lenses, and the reflected light reflected by the first lens surface side surface of the flange portion of the lens is formed as an imaging lens. The image of the reflected light is picked up by the image pickup means arranged at the image forming position of the image forming lens, and reflected by the surface on the first lens surface side of the flange portion of the lens picked up by the image pickup means An image of reflected light is displayed on a monitor screen.

  As described above, according to the present invention, the lens for the pickup device and the lens holder capable of detecting the direction of the gate trace of the lens with the optical axis as the origin and positioning the gate trace at a desired position of the holder of the pickup device. A positioning method with respect to is realized.

FIG. 1 is a top view of a lens according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a block diagram of the lens fixing device according to the first embodiment of the present invention. FIG. 4 shows an example of display contents on the monitor screen of the lens fixing device according to the first embodiment of the present invention. FIG. 5 is a top view of a lens according to the second embodiment of the present invention. FIG. 6 shows an example of the display content of the monitor screen of the lens fixing device according to the second embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a top view of a lens according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. As shown in FIG. 2, the lens 1 is formed in a lens shape 10 in which a first lens surface 11 and a second lens surface 12 are formed on both front and back surfaces, and in a flange shape on the outer edge of the lens portion 10. And a flange portion 20. The lens of this embodiment is attached to a pickup device, the first lens surface 11 is a lens surface on the optical disc side where information is read or recorded by the pickup device, and the second lens surface 12 is a light source side. This is the aspect.

Concentric annular surfaces 21, 22 and 23 centering on the optical axis ax ₁ of the lens 1 are formed on the surface of the flange portion 20 on the first lens surface 11 side. The innermost surface 21 is an optical axis ax ₁ perpendicular plane (edge reflection plane portion). The edge reflection flat part 21 reflects incident light with high reflectivity.

Further, the surface 22 adjacent to the edge reflection flat surface portion 21 is a truncated cone surface (edge reflection inclined surface portion) forming a part of a conical surface having an arbitrary point on the second lens surface 12 side on the optical axis ax ₁ as a vertex. is there. When incident light parallel to the optical axis ax ₁ is incident on the edge reflection inclined surface portion 22, the reflected light after the incident light is reflected on the edge reflection inclined surface portion 22 is at one point on the optical axis ax _1. Head. That is, the angle of the reflected light with respect to the optical axis ax ₁ is constant regardless of the incident light incident on any position on the edge reflection inclined surface portion 22. Further, the outermost surface 23 is a plane substantially perpendicular to the optical axis ax ₁ (outer flat portion).

  The lens 1 of the present embodiment is formed by injection molding. After the lens molded product having a shape in which the lens is connected to the sprue via the gate is molded, the lens 1 is separated from the lens molded product by cutting the gate. Therefore, as shown in FIGS. 1 and 2, a part of the gate is left as a gate mark 31 in a part of the outer peripheral cylindrical surface 24 of the flange portion 20.

  As shown in FIGS. 1 and 2, a non-reflective portion K is formed on the flange portion 20 adjacent to the gate mark 31 from the edge reflection flat portion 21 to the outer edge flat portion 23. The non-reflective portion K is a region in which the edge reflection flat surface portion 21, the edge reflection inclined surface portion 22 and the outer edge flat surface portion 23 are painted black with a paint or the like, and hardly reflects incident light. Or it is good also as a structure which forms the rough surface in the non-reflective part K so that the quantity of the light to reflect may become small enough.

  An inspection method for aligning the lens of the present embodiment described above will be described below. FIG. 3 is a block diagram showing an outline of a lens fixing device for fixing the lens 1 to the holder 50 of the pickup device.

  As shown in FIG. 3, the lens fixing device 100 includes a holder holding unit 110 that holds the holder 50, and a detection unit that detects the inclination of the optical axis of the lens 1 with respect to the holder 50 and the rotation angle around the optical axis of the lens 1. 120, a moving part 130 for moving the lens 1 on the holder 50, an adhesive part 140 for supplying an adhesive to the gap between the holder 50 and the lens 1 to fix the lens 1 to the holder 50, and a detecting part 120, moving An operation computer system 150 for operating the unit 130 and the bonding unit 140.

  The detection unit 120 includes a light source unit 121 that generates parallel light, a half mirror 122, an imaging lens 123, and an imaging camera 124.

The parallel light generated from the light source unit 121 enters the half mirror 122. The parallel light until it enters the half mirror 122 is defined as the first light P1. The half mirror 122 bends the incident first light P <b> 1 by 90 ° in the direction toward the lens 1. Light that is bent by the half mirror 122 and travels toward the lens 1 is defined as second light P11. The traveling direction D of the second light P11 is parallel to the optical axis ax ₁ (FIGS. 1 and 2) of the lens 1 when the lens 1 is correctly attached to the holder 50.

The second light P <b> 11 is reflected by the edge reflection flat surface portion 21 and the edge reflection inclined surface portion 22 of the lens 1. The light reflected by the lens 1 is defined as the third light P21. The third light P21 passes through the half mirror 122. The light after passing through the half mirror 122 is defined as the fourth light P2. The fourth light P <b> 2 is collected by the imaging lens 123 and enters the imaging camera 124. Here, the imaging lens 123, so that the optical axis parallel light parallel to the ax _i is condensed on the imaging surface of the imaging camera 124 is positioned relative to the imaging camera 124.

  The operation computer system 150 includes a computer main body 151, a monitor 152, and an operation unit 153 such as a keyboard and a mouse. The image output terminal of the imaging camera 124 is connected to the computer main body 151 of the operation computer system 150.

  The computer main body 151 processes the video signal transmitted from the imaging camera 124 and displays an image captured by the imaging camera 124 on the screen 152 a of the monitor 152. The light reflected by the edge reflection plane portion 21 of the lens 1 is displayed as a light spot S11 on the dark field on the screen 152a. Further, the computer main body 151 displays an inclination detection mark M on the screen 152a. The inclination of the optical axis of the lens 1 appears as a positional deviation between the mark M and the light spot S11.

  Further, the computer main body 151 can control the moving unit 130, and the operating unit 153 is operated to tilt the lens 1 by the moving unit 130 so that the light spot S 11 overlaps the mark M. The optical axis can be adjusted to the correct position.

  Further, the light reflected by the edge reflection inclined surface portion 22 of the lens 1 is displayed as a light ring S12 appearing around the light spot S11 on the screen. An example of the display content of the screen 152a is shown in FIG. In FIG. 4, the mark M in FIG. 3 is omitted.

As shown in FIG. 4, the halo S12 is a ring centered on the light spot S11, and a notch N is provided in a part thereof. This notch N corresponds to the non-reflecting portion K (FIGS. 1 and 2) of the lens 1. That is, from the notch N, the direction of the non-reflecting portion K from the optical axis ax ₁ (FIGS. 1 and 2) of the lens 1, in other words, the direction of the gate mark 31 relative to the optical axis ax ₁ can be determined. That is, the reflection portion K functions as a so-called gate mark region. Then, by operating the operation unit 153, the lens 1 is rotated around the optical axis by the moving unit 130 so that the notch N faces a predetermined direction (for example, upward in the drawing) with respect to the light spot S11. The gate mark 31 can be adjusted so that it faces the correct direction.

In order to the size of the on luminance and screen 152a of halo S12 and suitable are 3-10 minutes the slope of the edge reflection inclined plane portion 22 with respect to a plane perpendicular to the optical axis ax _1, preferably about 5 Minutes. Further, the outer edge plane part 23 is a plane perpendicular to the optical axis ax ₁ like the edge reflection plane part 21 so that the image by the reflected light at the outer edge plane part 23 becomes the light spot S11 or the outer edge plane part. 23 is a rough surface with relatively low reflectance, and the image by the outer edge plane portion 23 is displayed sufficiently darker than the light spot S11 and the light wheel S12.

  The computer main body 151 can control the bonding unit 140, and after positioning the lens 1 with respect to the holder 50 by the above operation, the operation unit 153 is operated to bond the positioned lens 1 to the holder 50. Can be fixed.

  As described above, according to the present embodiment, by forming a plurality of surfaces having different properties on the flange portion 20, the lens 1 can be properly positioned after the direction of inclination of the lens 1 and the rotation angle around the optical axis are correctly positioned. Can be fixed to the holder 50.

In the present embodiment, the non-reflective portion K (FIGS. 1 and 2) of the lens 1 is formed from the edge reflection flat portion 21 to the outer edge flat portion 23 of the lens 1. In order to perform positioning around the optical axis, it is only necessary that the non-reflective portion K is formed only at least on a part of the edge reflection slope portion 22. Further, in the present embodiment, the non-reflective portion K is formed by black-painting a part of the edge reflection slope portion 22, but the non-reflective portion K is formed as a rough surface that irregularly reflects light. At best, or a non-reflective portion K, it may be configured to form a plane perpendicular section to the optical axis ax _1.

Further, the non-reflective portion K does not necessarily need to be in a position close to the gate mark 31 and the positional relationship between the non-reflective part K and the gate mark 31 is clear (for example, the non-reflective part K and the gate mark 31 are 180 ° about the optical axis ax _1, 90 °, if there etc.) of the positional relationship between the 45 ° and the like, may be another position. Further, edge reflection inclined surface portion 22, the distance from the optical axis ax ₁ to edge reflection inclined plane portion 22 [delta] _{1 (FIG.} 2) a point on the second lens surface 12 in accordance with increases, for example, the second lens surface 12 and the optical axis The distance δ _{2 in} the direction along the optical axis ax ₁ from the point σ ₁ (FIG. 2) where the ax ₁ intersects (the surface and the edge perpendicular to the optical axis ax ₁ passing through one point on the second lens surface 12) This is an inwardly inclined surface with a large distance). In other words, the edge reflection inclined surface portion 22 is an inclined surface that reflects incident light parallel to the optical axis ax ₁ in a direction toward the optical axis. However, the present invention is not limited to the above-described configuration, and is along the optical axis ax ₁ from one point on the second lens surface 12 as the distance from the optical axis ax ₁ to the edge reflection inclined surface portion 22 decreases. An outwardly inclined surface (for example, a truncated cone surface forming a part of a conical surface having an arbitrary point on the first lens surface side on the optical axis ax ₁ as a vertex) on which the distance in the direction becomes large, that is, the optical axis It may be an inclined surface that reflects incident light parallel to ax ₁ in a direction away from the optical axis. However, when the edge reflection inclined surface portion 22 has an outward inclined surface, the halo S12 moving to the screen 152a becomes an image obtained by rotating the edge reflection inclined surface portion 180 by 180 degrees, and the lens 1 is rotated by the moving portion 130. The rotation direction of the lens 1 is opposite to the rotation direction of the optical ring S12. Therefore, the settings of the operation computer system 150 may be changed and adjusted as appropriate.

  In the first embodiment of the present invention described above, the edge reflection inclined surface portion 22 for detecting the position of the gate mark 31 is formed over the entire circumference in the circumferential direction of the lens 1 except for the vicinity of the gate mark 31. Has been. However, the present invention is not limited to the above-described configuration, and the edge reflection inclined surface portion may be formed only on a part of the lens 1 as in the second embodiment of the present invention described below. Good.

  FIG. 5 is a top view of the lens according to the second embodiment of the present invention viewed from the first lens surface side. Similar to the first embodiment, the lens 201 of the present embodiment includes a lens portion 210 and a flange portion 220 formed in a flange shape on the outer edge of the lens portion 210.

The surface of the flange portion 220 on the first lens surface 211 side is divided into an inner reflection side flat portion 221 (that is, adjacent to the first lens surface 211) and an outer peripheral flat portion 223 on the outer peripheral side. The edge reflection plane part 221 is formed in a plane shape perpendicular to the optical axis ax ₂ of the lens 201 as in the first embodiment, and reflects light incident on the edge reflection plane part 221 with a high reflectance. It is supposed to let you.

The outer edge plane part 223 is formed in a planar shape substantially perpendicular to the optical axis ax ₂ of the lens 201. Further, as shown in Figure 5, the outer flat portion 223, 90 ° clockwise around the optical axis ax ₂ with respect to the gate mark 231 formed on a portion of the outer cylindrical surface 224 of the flange portion 220, 180 Edge reflection slope portions 222a, 222b, and 222c are formed at positions of an angle of ° and 270 °, respectively. Each edge reflection inclined plane portion 222a, 222b, 222c are formed on a circumference around the optical axis ax _2.

Edge reflection inclined plane portion 222a, 222b, 222c are respectively the distance from the optical axis ax _2, the optical axis ax from a point on the second lens surface of the lens portion 210 (the lens surface is formed on the back side of the first lens surface) distance in _two directions, such as increases (i.e., the distance from the optical axis ax _2, the interval between the plane perpendicular to the optical axis ax ₂ passing through a point above that increases), an inclined plane. Further, edge reflection inclined plane portion 222a, 222b, of 222c, the inclination angle with respect to the optical axis ax ₂ are equal. Therefore, edge reflection inclined plane portion 222a, 222b, s husband 222c, when light is incident axis ax ₂ incident light parallel to, the edge reflection inclined plane portion 222a, 222b, the light reflected by the s husband 222c, light The angle with respect to the axis ax ₂ is constant.

  In order to fix the lens 201 described above to the holder of the pickup device, the lens fixing device 100 (FIG. 3) used in the first embodiment is used. When the lens 201 and the holder of this embodiment are attached to the lens fixing device 100, an image as shown in FIG. 6 is displayed on the screen 152a (FIG. 3) of the monitor 152 of the operation computer system 150.

Also in the present embodiment, the light reflected by the edge reflection flat portion 221 (FIG. 5) is displayed as a light spot S21 (FIG. 6) on the screen 152a (FIG. 3). Spot S21 is similar to the light spot S11 (FIG. 4) in the first embodiment, is used to detect the inclination of the optical axis ax ₂ of the lens 201. That is, when the optical axis ax ₂ not inclined, the light spot S21 is displayed (the position mark M is displayed in other words 3) position, whereas, if the inclined optical axis ax _2, the inclination Depending on the direction and degree, the light spot S21 is displayed at a position away from the predetermined position.

In addition, the light reflected by the edge reflecting slopes 222a, 222b and 222c (FIG. 5) is displayed as light spots S22a, S22b and S22c on the screen 152a (FIG. 3), respectively. As shown in FIG. 6, the light spots S22a, S22b, and S22c are in the same direction as the arrangement order of the edge reflection slope portions 222a, 222b, and 222c, that is, 90 clockwise on the circumference centered on the light spot S21. Arranged every °°. The light spot S22a, in a virtual square Q whose vertices S22b and S 22 c, the vertex _{The T g} spot is not displayed, is used to indicate the orientation of the gate mark 231 (FIG. 5). That is, the direction from point S21 to the vertex The _{T g} equal to the direction toward the gate remain 231 from the optical axis ax ₂ of the lens 201 (FIG. 5).

As described above, in this embodiment as well, as in the first embodiment, the inclination of the optical axis ax ₂ of the lens 201 and the position of the gate mark 231 around the optical axis ax ₂ can be detected. Based on this, it is possible to fix the lens 201 to the holder of the pickup device after correctly positioning the tilt direction of the lens 201 and the rotation angle around the optical axis.

Here, the outer edge plane part 223 is a plane perpendicular to the optical axis ax ₂ like the edge reflection plane part 221. That is, when the incident light parallel to the optical axis ax ₂ is incident on the outer edge plane portion 223, the direction of the reflected light (that is, the angle of the reflected light with respect to the optical axis ax ₂ ) is the same direction. The direction of the reflected light is different from that when the light is incident on 222a, 222b and 222c. In this case, the image by the reflected light at the outer edge plane portion 223 becomes the light spot S21.

  Alternatively, the outer edge plane portion 223 is configured as a rough surface with relatively low reflectance so that the image by the outer edge plane portion 223 is displayed sufficiently darker than the light spots S21, S22a, S22b, and S22c.

As in the first embodiment, the light spot S22a, in order to S22b and (Distance from point S21) position on brightness and screen 152a of S22c a suitable are perpendicular to the optical axis ax ₂ The inclination of the edge reflection slopes 222a, 222b and 222c with respect to a flat surface is 3 to 10 minutes, preferably about 5 minutes.

The edge reflection slope portions 222a, 222b, and 222c may be arranged at other positions where the position of the gate mark 231 can be detected from the light spot by the edge reflection slope portion, and the number thereof can be set as appropriate. . For example, the edge reflection slope portion may be formed only in the vicinity of the gate mark 231. Further, edge reflection inclined plane portion 222a, 222b and 222c pass through the optical axis ax ₂ direction of distances (the one point from a point on the second lens surface of the lens 201 according to the distance from the optical axis ax ₂ increases the light distance between a plane perpendicular to the axis ax ₂₎ such increase, but an inclined surface inwardly, the present invention is not limited to the above configuration, the distance from the optical axis ax ₂ is reduced Accordingly, an outwardly inclined surface that increases the distance from one point on the second lens surface may be used. However, if the edge reflection slopes 222a, 222b, and 222c are outwardly inclined surfaces, the light spots S22a, 22b, and 22c moving to the screen 152a (FIG. 3) are images obtained by rotating the corresponding edge reflection slopes by 180 °. Thus, when the lens 1 is rotated by the moving unit 130 (FIG. 3) of the lens fixing device 100, the rotation direction of the lens 1 and the rotation direction of the optical ring S12 are reversed. Therefore, the settings of the operation computer system 150 may be changed and adjusted as appropriate.

DESCRIPTION OF SYMBOLS 1 Lens 21 Edge reflection plane part 22 Edge reflection slope part 31 Gate trace 100 Lens fixing device 120 Detection part 201 Lens 221 Edge reflection plane part 222a, 222b, 222c Edge reflection slope part 231 Gate trace

Claims (12)

A lens for a pickup device formed by injection molding,
A lens part having a first lens surface and a second lens surface formed on the front and back;
A flange portion protruding in a flange shape from an edge portion of the lens portion;
Have
On the surface of the flange portion on the first lens surface side, incident light that is inclined with respect to the optical axis of the lens and is incident in parallel to the optical axis is reflected at a constant angle with respect to the optical axis. The edge reflection slope part that reflects is formed,
The edge reflection inclined surface portion is provided on a circumference centering on the optical axis of the lens, and on the circumference and at a predetermined position with respect to the gate trace of the lens, in parallel with the optical axis. A gate mark region that does not reflect incident light in the reflection direction is formed ,
On the surface of the flange portion on the first lens surface side, an edge reflection plane portion that is a plane perpendicular to the optical axis of the lens surface is formed.
Lens for pickup device. A lens for a pickup device formed by injection molding,
A lens part having a first lens surface and a second lens surface formed on the front and back;
A flange portion protruding in a flange shape from an edge portion of the lens portion;
Have
On the surface of the flange portion on the first lens surface side, incident light that is inclined with respect to the optical axis of the lens and is incident in parallel to the optical axis is reflected at a constant angle with respect to the optical axis. The edge reflection slope part that reflects is formed,
The edge reflection inclined surface portion is provided on a circumference centering on the optical axis of the lens, and on the circumference and at a predetermined position with respect to the gate trace of the lens, in parallel with the optical axis. A gate mark region that reflects incident incident light in a direction different from the reflection direction is formed ,
Lens for pickup device. The flange portion is formed with a conical surface centered on the optical axis of the lens,
The gate mark region is formed over the entire radial direction of a part of the conical surface,
The edge reflection slope portion is formed in a portion other than the gate mark region of the conical surface .
A lens for a pickup device according to claim 1 or 2. The gate mark region is formed at a position close to the gate mark of the lens ,
Lens for pickup apparatus according to any one of claims 1 to 3. The gate mark region is a non-reflective portion that does not substantially reflect light incident on the gate mark region .
The lens for a pickup device according to claim 3 or 4 , wherein the lens according to claim 1 is cited . A lens for a pickup device formed by injection molding,
A lens part having a first lens surface and a second lens surface formed on the front and back;
A flange portion protruding in a flange shape from an edge portion of the lens portion;
Have
On the surface of the flange portion on the first lens surface side, incident light that is inclined with respect to the optical axis of the lens and is incident in parallel to the optical axis is reflected at a constant angle with respect to the optical axis. The edge reflection slope part that reflects is formed,
The edge reflection slope is provided on a circumference centered on the optical axis of the lens, and a predetermined position on the circumference with respect to the gate trace of the lens (excluding a position close to the gate trace). ) Is formed with a gate mark region that does not reflect the incident light incident parallel to the optical axis in the reflection direction .
Lens for pickup device. A lens for a pickup device formed by injection molding,
A lens part having a first lens surface and a second lens surface formed on the front and back;
A flange portion protruding in a flange shape from an edge portion of the lens portion;
Have
On the surface of the flange portion on the first lens surface side, incident light that is inclined with respect to the optical axis of the lens and is incident in parallel to the optical axis is reflected at a constant angle with respect to the optical axis. The edge reflection slope part that reflects is formed,
The edge reflection inclined surface portion is provided on a circumference centering on the optical axis of the lens, and on the circumference and at a predetermined position with respect to the gate trace of the lens, in parallel with the optical axis. A gate mark region that does not reflect incident light in the reflection direction is formed ,
A plurality of the edge reflection slope portions are formed along a circumference provided with the edge reflection slope portion.
A flat slope,
The plurality of edge reflection slope portions are formed at positions shifted by a predetermined angle around the optical axis of the lens from a position close to a gate trace of the lens on a circumference where the edge reflection slope portion is provided. And
The gate mark region is formed at a position including the position close to the gate mark of the lens and where the edge reflection slope portion is not formed, and incident light parallel to the optical axis is directed in a direction other than the reflection direction. The part that reflects,
Lens for pickup device. The gate mark region is a plane portion perpendicular to the optical axis of the lens ,
The lens for a pickup device according to claim 7. The edge reflection slope portion is an inward slope whose reflection direction is a direction toward the optical axis .
What Re or lens for pick-up apparatus described in one of claims 1 to 8. The edge reflection slope portion is an outward slope whose reflection direction is away from the optical axis .
What Re or lens for pick-up apparatus described in one of claims 1 to 8. The first lens surface is a lens surface located on the optical disc side where information is read or recorded by the pickup device .
What Re or lens for pick-up apparatus described in one of claims 1 to 10. What Re or is incident parallel light to the first lens surface of the lens according to one of claims 1 to 11,
The reflected light reflected by the first lens surface side surface of the flange portion of the lens is incident on the imaging lens, and an image by the reflected light is captured by an imaging unit disposed at the imaging position of the imaging lens,
Displaying an image of the reflected light reflected by the surface of the flange portion of the lens on the first lens surface side imaged by the imaging means on the screen of the monitor ;
Lens inspection method.

Images