JP2010181742A - Hybrid lens, method for manufacturing the same, and optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce, to the utmost, reflection of light at the boundary between glass and a resin in a hybrid lens composed of the glass and the resin. <P>SOLUTION: In the hybrid lens 1 composed of glass 3 and resins 5, 7, the boundary between the glass 3 and each of the resins 5, 7 is formed into an uneven shape having a period smaller than the wavelength of light. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hybrid lens, a method for manufacturing a hybrid lens, and an optical element, and relates to a lens composed of, for example, glass and resin.

  Currently, camera modules including lenses are being used for digital cameras, camera-equipped mobile phones, other surveillance cameras, and in-vehicle cameras in the future.

  Among the above applications, there is a great need for reducing the scale of optical systems in mobile products such as digital cameras and mobile phones. Therefore, it is necessary to integrate a plurality of optical elements in one device.

  For example, by producing a diffraction grating groove on the surface of the lens, a composite function of the diffractive optical element and the lens can be realized, the number of optical elements and storage space can be reduced, and the optical axis adjustment process of the two optical elements Can be omitted (see FIG. 21). Incidentally, the diffraction grating is an optical device that has irregularities on a flat surface or a lens surface, and changes the optical path length of light passing through the flat plate or inside the lens, thereby eliminating wavefront aberration and chromatic aberration. Since the beam cross section is generally circular, the diffraction grating device is provided with concentric grooves.

  However, in the case of a glass lens, such fine groove processing cannot be performed or is extremely difficult. Usually, a glass mold is manufactured from a super hard material having high heat resistance, but since it has high hardness, only grinding can be performed, and fine concentric grooves as described above are difficult or extremely difficult.

  On the other hand, the mold material used in plastic lens molding has a lower hardness than cemented carbide materials, and fine cutting with a cutting tool is possible, so that diffraction grating grooves can be processed. On the other hand, the range of use is limited because of material demerits such as “small variations in optical constants such as refractive index and Abbe number” and “poor heat resistance”.

  In order to eliminate such disadvantages of glass and plastic, a hybrid lens 201 is made. This is made of a composite material of glass 203 and resins 205 and 207. That is, a plastic (resin 205, 207) is used for a surface portion that requires a fine shape 209 such as a diffraction grating, and glass 203 is used inside (see FIG. 22).

  For example, an ultraviolet curable resin (UV curable resin) is used for the portions of the resins 205 and 207 in FIG. The resins 205 and 207 are usually low in viscosity like water and are cured by being irradiated with ultraviolet rays before being cured. Since the viscosity before curing is low, it is possible to sufficiently fill the fine grooves with the resins 205 and 207 by capillary action.

  By the way, as a technique related to the conventional hybrid lens 201, for example, Patent Document 1 can be cited.

JP 2000-180602 A

  However, as shown in FIG. 23, the optical constants such as the refractive index and the Abbe number are different between the resin 205 and 207 portions and the glass 203 portion. Reflection always occurs at interfaces having different optical constants (boundary surfaces between the resins 205 and 207 and the glass 203), and part of the light incident on the hybrid lens 201 as indicated by an arrow A11 is combined with the resins 205 and 207. The light is reflected at the interface with the glass 203 and returns to the light source side (see arrow A13). For this reason, the amount of light reaching the photosensitive portion (photosensitive side) is reduced, or the light returned to the light source side is re-reflected and re-enters the hybrid lens 201 again, resulting in deterioration of the obtained image, such as generation of stray light. cause.

  As the resins 205 and 207, a UV curable resin having the same refractive index as that of the glass 203 is also used. However, if the Abbe number is different, stray light is generated depending on the wavelength of light. Such a countermeasure is effective for monochromatic light as in optical communication, but in a normal camera module that handles light of various wavelengths, stray light is generated depending on the wavelength.

  It is very difficult to develop a plastic material in which both the refractive index and the Abbe number are the same as those of glass.

  As described above, the conventional hybrid lens 201 has a problem that stray light is generated to a greater or lesser extent, and a reduction in the amount of light on the photosensitive portion is unavoidable.

  The present invention has been made in view of the above problems, and in a hybrid lens composed of glass and resin, a method for manufacturing a hybrid lens, and an optical element, the reflection of light at the boundary between glass and resin is minimized. The object is to provide what can be reduced.

  According to the first aspect of the present invention, in the hybrid lens composed of glass and resin, the boundary between the glass and the resin is formed in a fine uneven shape having a period smaller than the wavelength of light. This is a featured hybrid lens.

  The invention according to claim 2 is a hybrid lens having a glass whose surface is configured in a moth-eye structure and a resin that is in close contact with the surface of the glass and covers the glass.

  In the invention according to claim 3, each surface perpendicular to the optical axis is formed in a fine uneven shape having a period smaller than the wavelength of transmitted light, and the glass is formed in a fine uneven shape. One surface that is in close contact with the glass and the first resin that is provided integrally with the glass, and the other surface of the glass that is formed in a fine uneven shape is in close contact with the glass And a second lens integrally provided on the glass.

  According to a fourth aspect of the present invention, there is provided a fine irregularity forming step for forming fine irregularities having a period smaller than the wavelength of light transmitted through the glass on the surface of the glass, and a resin molding die. And a resin installation step of providing a resin on a surface on which unevenness is formed.

  According to a fifth aspect of the present invention, in the optical element composed of a first material that transmits light and a second material that transmits light, the boundary between the materials is a period smaller than the wavelength of the light. It is an optical element formed in a fine uneven shape.

  Advantageous Effects of Invention According to the present invention, in a hybrid lens composed of glass and resin, a method for manufacturing a hybrid lens, and an optical element, there is an effect that reflection of light at the boundary between glass and resin can be minimized.

It is a figure which shows schematic structure of the hybrid lens 1 which concerns on embodiment of this invention. It is an enlarged view of the II section in FIG. 2 is a diagram showing an outline of a manufacturing process of the hybrid lens 1. FIG. FIG. 3 is a perspective view showing a schematic configuration of a conical protrusion 13 constituting fine irregularities 9 of glass 3. FIG. 5 is a view taken in the direction of arrow V in FIG. 4. FIG. 6 is a perspective view showing a schematic configuration of a modified example related to the arrangement of the conical protrusions 13. It is a VII arrow line view in FIG. FIG. 8 is a diagram corresponding to FIG. 5 and FIG. 7, and is a diagram illustrating a modification example related to the arrangement of the conical protrusions 13. FIG. 8 is a diagram corresponding to FIG. 5 and FIG. 7, and is a diagram illustrating a modification example related to the arrangement of the conical protrusions 13. FIG. 6 is a perspective view showing a schematic configuration of a modified example of a protrusion 13. It is a XI arrow line view in FIG. FIG. 12 is a diagram corresponding to FIG. 11, and is a diagram illustrating a modified example related to the arrangement of the quadrangular pyramid-shaped protrusions 13. It is a figure corresponding to FIG. 11 etc., Comprising: It is a figure which shows arrangement | positioning of the hexagonal pyramid-shaped protrusion 13. FIG. It is a figure which shows the cross section of the modification of the processus | protrusion 13. FIG. It is a figure which shows the cross section of the modification of the processus | protrusion 13. FIG. It is a figure which shows the cross section of the modification of the processus | protrusion 13. FIG. FIG. 6 is a perspective view showing a schematic configuration of a modified example of a protrusion 13. It is a XVIII arrow directional view in FIG. It is an expanded view of the protrusion 13 shown in FIG. It is a figure which shows the XXA-XXA cross section in FIG. 18, and a XXB-XXB cross section. It is a figure which shows schematic structure of the conventional lens which formed the diffraction grating groove | channel on the lens surface, and implement | achieved the composite function of a diffractive optical element and a lens. It is a figure which shows schematic structure of the conventional hybrid lens 201 comprised with resin and glass. It is a figure which shows the reflective state of the light in the conventional hybrid lens 201. FIG.

  FIG. 1 is a diagram showing a schematic configuration of a hybrid lens 1 according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a portion II in FIG.

  The hybrid lens 1 includes a glass 3 and resins 5 and 7.

  For example, an ultraviolet curable resin (UV curable resin) is used as the resins 5 and 7. Although the refractive index and Abbe number of the resins 5 and 7 are different from those of the glass 3, at least one of the refractive index and the Abbe number may be substantially equal to that of the glass 3. The resins 5 and 7 are provided in close contact with the glass 3 and laminated so that light (for example, visible light) passes through the glass 3 and the resins 5 and 7.

  The boundary between the glass 3 and the resin 5 is formed in a fine concavo-convex shape having a period (pitch P1 shown in FIG. 2) smaller than the wavelength of light transmitted through the hybrid lens 1. Similarly, the boundary between the glass 3 and the resin 7 is also formed in fine irregularities having a period smaller than the wavelength of light transmitted through the hybrid lens 1. That is, the hybrid lens 1 includes a glass 3 having a moth-eye structure (a fine concavo-convex structure with a submicrometer period) on the surface, and a resin 5 that is in close contact with the surface of the glass 3 and covers the glass 3. is doing.

  The hybrid lens 1 is a convex lens, and light travels from the left side of FIG. 1 to the right side as indicated by an arrow A1 shown in FIG. The hybrid lens 1 is formed in, for example, a circular shape when viewed from the light traveling direction (the optical path direction).

  The glass 3 is formed in a flat plate shape (for example, a circular flat plate shape), and is located on both sides of the glass 3 perpendicular to the optical axis of the hybrid lens 1 (on one side in the thickness direction of the glass 3). The surface and the surface located on the other side) are formed in a fine uneven shape (see FIG. 2). That is, on both surfaces of the glass 3 perpendicular to the optical axis, fine irregularities (unevenness integral with the main body portion of the glass 3) 9 having a period smaller than the wavelength of light to be transmitted are provided.

  The resin 5 is one surface in the optical axis direction of the glass 3 (one surface on which the fine unevenness 9 is provided), is in close contact with the glass 3 and is provided integrally with the glass 3, The other surface of the glass 3 in the optical axis direction (the other surface on which the fine unevenness 9 is provided) is in close contact with the glass 3 and provided integrally with the glass 3. When viewed from the traveling direction of light, the resins 5 and 7 are formed in a circular shape, for example, and the resin 5 and the resin 7 overlap each other. Further, the center of the resin 5 and the resin 7 and the center of the glass 3 (the center serving as the optical axis) coincide with each other, and the resin 5 and the resin 7 are provided at the center of the glass 3. Thereby, resin is not provided in the annular | circular periphery part of the glass 3, but the glass 3 is exposed.

  The height H1 (see FIG. 2) of the fine irregularities 9 at the boundary between the glass 3 and the resin 5 and at the boundary between the glass 3 and the resin 7 is often higher than the value of the wavelength of light, for example.

  The form of the boundary between the glass 3 and the resins 5 and 7 will be further described. The direction of the optical axis of the hybrid lens 1 (the left-right direction in FIGS. 1 and 2) is the height direction of a large number of fine irregularities 9, and the direction substantially orthogonal to the optical axis of the hybrid lens 1 (in FIGS. 1 and 2). The vertical direction (the direction perpendicular to the plane of FIG. 1 and FIG. 2) is the direction in which many fine irregularities 9 are arranged, that is, the direction of the period of the fine irregularities 9.

  The fine irregularities 9 in the glass 3 are a large number of fine protrusions standing from the base surface 11 of the glass 3 (the glass 3 and the resins 5 and 7 are raised at a height of H1 in the thickness direction of the glass 3 and the resin 3. 5 and 7 in a direction substantially orthogonal to the thickness direction, and a plurality of fine protrusions 13 arranged at a predetermined pitch P1. Here, the base surface 11 is a surface formed by connecting the valley bottoms 15 of a large number of fine irregularities 9 of the glass 3 (virtually developed in a direction substantially perpendicular to the thickness direction of the glass 3 and the resins 5 and 7. Flat surface).

  Each protrusion 13 is formed of a large number of fine cones standing up from the base surface 11 (cones standing up from the base surface 11 so that the bottom surface is in contact with the base surface 11) (FIGS. 4 and 5). reference). 4 and FIG. 5, only four protrusions 13 are shown, but in actuality, fine irregularities 9 are formed by a large number of protrusions 13.

  The heights H1 of the protrusions 13 are equal to each other. Further, resins 5 and 7 are provided so that no gap is generated between the glass 3 and the fine irregularities 9 (projections 13). That is, the resins 5 and 7 are provided so as to be in close contact with the glass 3 and fill in the fine irregularities 9 of the glass 3. As a result, a large number of fine irregularities are also formed on the resins 5 and 7. Further, at the boundary between the glass 3 and the resin 5 and the boundary between the glass 3 and the resin 7, the glass 3 and the resin 5 (glass 3 and the resin 7) in the direction in which the boundary is developed (the development direction of the base surface 11). Are interleaved with each other.

  By the way, each of the conical protrusions 13 shown in FIGS. 4 and 5 has the vertical direction and the bottom surfaces (circular bottom surfaces) in contact with each other when viewed from the direction orthogonal to the base surface 11. They are provided side by side at a predetermined pitch P1 in the horizontal direction. Thus, the relationship between the pitch P1 of each protrusion 13 and the radius R1 of the bottom surface of the protrusion 13 is “2 × R1 = P1”.

  Further, when viewed from a direction orthogonal to the base surface 11, the first straight line group in which the vertices 17 of the protrusions 13 are parallel to each other and drawn on the plane at a predetermined equal interval, It is orthogonal to one straight line group and is located on each intersection with the second straight line group drawn on the plane at the predetermined equal intervals. Furthermore, a part of the planar base surface 11 exists. 4 and 5, the protrusions 13 are in contact with each other, but the protrusions 13 (the bottom surfaces of the protrusions 13) may be separated by a predetermined distance.

  Further, as shown in FIGS. 6 and 7, the distance between the protrusions 13 may be made smaller than the state shown in FIGS. 4 and 5 so that the planar base surface 11 does not exist. In this case, the relationship between the pitch P1 of each protrusion 13 and the radius R1 of the bottom surface of the protrusion 13 is “2 × R1 = √2 × P1”.

  Further, as shown in FIG. 8, the distance between the protrusions 13 may be a value between the distance shown in FIGS. 4 and 5 and the distance shown in FIGS. In this case, the relationship between the pitch P1 of each protrusion 13 and the radius R1 of the bottom surface of the protrusion 13 is “√2 × R1 <P1 <2 × R1”.

  Further, in the embodiment shown in FIGS. 5, 7, and 8, the pitch of the protrusions 13 in the left-right direction of the drawing and the pitch of the protrusions 13 in the vertical direction of the drawing may have different values. .

  Furthermore, as shown in FIG. 9, when viewed from a direction orthogonal to the base surface 11, the protrusions 13 are arranged so that the bottom surfaces (circular bottom surfaces) of the protrusions 13 are in contact with each other. They may be provided side by side at a predetermined pitch P1 in an oblique direction. Accordingly, the relationship between the pitch P1 of each protrusion 13 and the radius R1 of the bottom surface of the protrusion 13 is “2 × R1 = P1”. Further, when viewed from a direction orthogonal to the base surface 11, the first straight line group in which the vertices 17 of the protrusions 13 are parallel to each other and drawn on the plane at a predetermined equal interval, One straight line group intersects at an angle of 60 ° and is located on each intersection with the second straight line group drawn at the predetermined equal interval on the plane. Furthermore, a part of the planar base surface 11 exists.

  In addition, you may change the aspect of installation of each protrusion 13 shown in FIG. 9 like what is shown in FIG.7 and FIG.8.

  4 to 9, the protrusion 13 is formed in a conical shape, but as shown in FIGS. 10 and 11, the protrusion 13 is formed in a quadrangular pyramid shape (for example, a pyramid shape; a regular quadrangular pyramid shape). Also good. In this case, similarly to the case shown in FIG. 5, the vertex 17 of each projection 13 is located at the intersection of each straight line group. A line segment indicated by a broken line in FIG. 11 is a ridge line of the protrusion 13.

  Also, as shown in FIG. 12, the regular tetragonal pyramidal projections 13 may be provided with a half-pitch offset. A line segment indicated by a broken line in FIG. 12 is also a ridge line of the protrusion 13.

  Furthermore, as shown in FIG. 13, each protrusion 13 may be formed in a regular hexagonal pyramid shape, or may be formed in another cone shape such as a regular polygonal pyramid shape. A line segment indicated by a broken line in FIG. 13 is also a ridge line of the protrusion 13.

  Further, as shown in FIG. 14, each protrusion 13 is raised from a base surface 11 such that a truncated cone or a regular polygonal frustum (a bottom surface which is a large diameter side surface is in contact with the base surface 11). 15 may be formed, and as shown in FIG. 15, each protrusion 13 may be formed of a columnar body such as a cylinder or a regular polygonal column. Furthermore, as shown in FIG. 16, each protrusion 13 may be formed in other shapes such as a bell shape.

  Furthermore, as shown in FIGS. 17-20, the form of the fine unevenness | corrugation 9 between the glass 3 and resin 5 (resin 7) may be provided with symmetry. That is, the fine unevenness 9 of the glass 3 and the fine unevenness of the resin 5 (resin 7) may be formed in the same shape, and the resin 5 (resin 7) may be installed on the glass 3 without a gap.

  Here, an example in which the shape of the fine unevenness 9 between the glass 3 and the resin 5 (resin 7) has symmetry will be described.

  The surface of the glass 3 (the surface on which the protrusions 13 are continuously provided at a predetermined pitch P1 with no gaps) is formed in a shape that combines the diamonds D1 (see FIG. 19). FIG. 19 is a development view of one protrusion 13 shown in FIG. 17 and FIG. 18.

  As shown in FIG. 19, one protrusion 13 can be developed into a shape in which four rhombuses (one rhombus L1 whose rhombus L1 is longer than the other diagonal L2) D1 are combined. Then, in FIG. 19, each dotted line L <b> 3 is folded in a mountain, and each side L <b> 4, L <b> 5 is joined to each other, thereby forming one projection (one quadrangular pyramid-shaped projection) 13 by four rhombuses D <b> 1. When viewed from a direction orthogonal to the basal plane 11, one protrusion 13 is square as shown in FIG. Further, the fine unevenness 9 on the surface of the glass 3 is formed in a shape in which one protrusion 13 that looks like a square is regularly connected in the vertical and horizontal directions.

  In FIG. 18, the point 17 is the apex of the protrusion 13 (the apex of the unevenness 9), and the point 19 indicates the valley point (the deepest point) of the fine unevenness 9 on the surface of the glass 3. In FIG. 18, a broken line indicates a ridge line of each protrusion 13, and a solid line indicates a valley line of each protrusion 13.

  In FIG. 18, each protrusion 13 looks square, but each protrusion 13 may be formed to look rectangular. That is, in FIG. 18, the vertical direction may be reduced at a certain rate.

  Next, the form of the surface of resin 5 (resin 7) (surface in contact with air) will be described.

  In the hybrid lens 1, a diffraction grating 21 may be provided on the surface (boundary surface with air) of the resin 5 (resin 7) located on the opposite side of the boundary with the glass 3 (see FIG. 1). ). The diffraction grating 21 is provided to eliminate wavefront aberration and chromatic aberration by changing the optical path length of the light passing through the inside of the hybrid lens 1. For example, a concentric micron-order fine groove centered on the optical axis. Or it comprises a protrusion.

  In addition to or in addition to the diffraction grating 21, the surface of the resin 5 (resin 7) (surface in contact with air) has a period smaller than the wavelength of the transmitted light in the same manner as the boundary between the resin 5 and the glass 3. Fine irregularities may be formed.

  Next, the manufacturing process of the hybrid lens 1 will be described.

  FIG. 3 is a diagram illustrating a manufacturing process of the hybrid lens 1.

  First, fine irregularities 9 having a period smaller than the wavelength of light transmitted through the glass 3 are formed on the surface of the glass 3 (both surfaces of the glass 3 perpendicular to the optical axis of the hybrid lens 1).

  Formation of the fine unevenness 9 on the glass 3 is performed by, for example, a photolithography process used in a semiconductor manufacturing process. It should be noted that fine irregularities are formed in a material such as amorphous carbon (glassy carbon) or silicon carbide (silicon carbide, chemical formula SiC) by a photolithography process, and a glass mold (mold) ), Fine irregularities 9 may be formed on the glass 3.

  Subsequently, the resin 5 (resin 7) is provided on the surface of the glass 3 on which the fine irregularities 9 are formed using a resin mold (mold) 23.

  That is, the glass 3 on which fine irregularities 9 are formed is placed on a mold 23 made of tool steel or the like (see FIG. 3A). The glass 3 is placed so as to close the recess 27 formed in the flat surface 25 of the mold 23. When the diffraction grating 21 or the like is formed on the surface of the resin 5 (resin 7) of the hybrid lens 1, the pattern of the diffraction grating 21 is formed on the surface of the concave portion 27 of the mold 23. In addition, in a state where the glass 3 is installed in the mold 23, the periphery of the glass 3 is in close contact with the flat surface 25 around the recess 27 of the mold 23, and one surface on which the fine unevenness 9 of the glass 3 is formed. A space 29 into which the resin 5 enters is formed by the surface of the recess 27 of the mold 23. Subsequently, the atmosphere of the mold 23 and the glass 3 is preferably set to a vacuum or a state close to a vacuum, and a UV curable resin before curing is supplied to the space 29 to fill the space 29 with the UV curable resin. The UV curable resin supplied inside is irradiated with ultraviolet rays as shown by an arrow A3 to cure the UV curable resin (see FIG. 3B).

  Subsequently, the glass 3 on which the cured resin 5 is formed on one side is separated from the mold (see FIG. 3C) and turned over, and the resin molding mold (mold; resin 5) made of tool steel or the like is turned over. It is the same mold as that used when providing the, but may be a different mold. This installation is also performed so as to block the recess formed in the plane of the mold. In the state in which the glass 3 is installed in the mold, the periphery of the glass 3 is in close contact with the surface around the concave portion of the mold, as in the state described above, and the fine irregularities 9 of the glass 3 are formed. A space is formed between the other surface and the surface of the recess of the mold. Subsequently, the resin before curing is supplied to the space, the space is filled with resin, and the resin supplied into the space is cured. Thereby, the resin 7 is installed on the other surface of the glass 3.

  The hybrid lens 1 will be further described.

  The outer diameter (diameter) of the hybrid lens 1 shown in FIG. 1 is 5 mm, and UV curable resins 5 and 7 having a lens surface shape are provided on both surfaces of a circular glass substrate (glass) 3 having a diameter of 5 mm. Yes. Note that the interface 1 and the interface 2 () between the glass substrate 3 and the UV curable resin layers 5 and 7 have pyramid-shaped fine irregularities 9 having a period (pitch P1) of about 350 nm and a height H1 of about 350 nm. Is provided.

  The concave portion 27 of the mold 23 has a predetermined optical surface shape. Since the UV curable resin before curing has a very low viscosity, care must be taken not to tilt the mold 23 when the space 29 is filled with the UV curable resin before curing.

  The irradiation of ultraviolet rays is performed from the surface of the glass 3 with a predetermined amount of light for a predetermined time. As a result, the UV curable resin between the mold 23 and the glass substrate (glass) 3 is cured, and thereafter, when the mold is released, a lens as shown in FIG. 3C is completed.

  However, since the shrinkage occurs when the UV curable resin is cured, the surface shape of the mold 23 and the surface shape of the molded product are shifted. Therefore, it is necessary to obtain the amount of shrinkage in advance and redesign and process the shape of the mold 23 so that a predetermined surface shape can be obtained with the molded product.

  When light was transmitted through the hybrid lens 1 and the reflection was measured, the reflectance could be reduced to 1/10.

  According to the hybrid lens 1, the boundary between the glass 3 and the resin 5 (resin 7) is formed in a fine uneven shape with a period smaller than the wavelength of light (because it has a moth-eye structure). The effective refractive index and Abbe number of the boundary portion smoothly change in the direction from the resin 5 to the glass 3 or from the glass 3 to the resin 7 (in the direction of the optical path that passes through the hybrid lens 1). Due to the smooth change of the refractive index and the Abbe number, the light incident on the hybrid lens 1 cannot determine the boundary between the resin 5 (resin 7) and the glass 3, and the resin 5 (resin 7). And reflection of light at the boundary between the glass 3 and the glass 3 are almost eliminated. The optical performance of the hybrid lens 1 is improved by preventing light reflection at the boundary between the resin 5 (resin 7) and the glass 3.

  Further, according to the hybrid lens 1, even when the refractive index and Abbe number of the glass 3 and the resin 5 (resin 7) are different from each other, light is reflected at the boundary between the resin 5 (resin 7) and the glass 3. Therefore, reflection of light at the boundary between the resin 5 (resin 7) and the glass 3 can be performed in a simple manner without newly developing a resin having the same refractive index and Abbe number as that of the glass 3. Therefore, the generation of stray light or the decrease in the amount of light reaching the photosensitive portion can be prevented.

  Further, since the hybrid lens 1 is composed of the glass 3 and the resin 5 (resin 7), the rigidity of the hybrid lens 1 is increased and the hybrid lens 1 is compared with the case where it is composed only of the resin. It becomes hard to break. In addition, the hybrid lens 1 can be easily assembled to a device such as a camera. That is, when the hybrid lens 1 is installed in a device such as a camera, the portion of the glass 3 of the hybrid lens 1 (the portion having higher rigidity and hardness than the resin 5 and the resin 7) is engaged with the device such as a camera. It becomes easy to install the hybrid lens 1 at a correct location of a device such as a camera.

  According to the hybrid lens 1, since the resins 5 and 7 are provided on both surfaces of the glass 3, the design freedom in the hybrid lens 1 can be increased.

  Further, in the hybrid lens 1, if the diffraction grating 21 is provided on the surfaces of the resins 5 and 7, wavefront aberration and chromatic aberration can be eliminated. Further, if fine irregularities having a period smaller than the wavelength of light to be transmitted are formed on the surfaces of the resins 5 and 7, light reflection on the surfaces of the resins 5 and 7 Reflection due to a difference in refractive index can be prevented.

  In the hybrid lens 1, if the height H1 of the fine irregularities 9 (each projection 13) is formed lower than the wavelength of light, light reflection can be further avoided.

  Moreover, if the glass 3 of the hybrid lens 1 has a flat plate shape, it is possible to easily form fine irregularities 9 on the glass 3. That is, since the glass 3 is formed in a flat plate shape, resist application, exposure, and the like in a photolithography process for forming fine irregularities 9 are facilitated. Further, since the glass 3 is formed in a flat plate shape, when the fine irregularities 9 are formed on the glass 3 using a mold (a mold different from the mold 23 shown in FIG. 3), the fine irregularities The glass 3 formed with 9 is easily separated from the mold, and the glass 3 can be easily released. That is, since the fine protrusions 13 stand substantially perpendicularly from the flat base surface 11 of the glass 3, the protrusions 13 and the fine uneven pattern of the mold interfere when the glass 3 is separated from the mold. The glass 3 can be easily released from the mold.

  Further, according to the hybrid lens 1, when the glass 3 provided with the resin 5 (resin 7) is separated from the mold 23, a force can be applied to the portion of the glass 3 having high rigidity and hardness. It is possible to easily release the glass 3 on which the resin 7) is installed (separation from the mold 23).

  Further, according to the hybrid lens 1, when the glass 3 is installed in the mold 23 or when the glass 3 having the cured resin 5 formed on one surface is turned over and installed in the mold 23, the rigidity or hardness of the lens 1 is increased. Since it is only necessary to engage the mold 23 with the high glass 3 portion as a positioning reference, the glass 3 can be placed on the mold 23 accurately and easily. The installation position of 7) can be made accurate.

  Further, since the mold 23 is for molding the resins 5 and 7 and placing them on the glass 3, the mold 23 can be made of tool steel or the like, and the mold 23 can be cut. In addition, it is easy to create the mold 23 in the case of forming micron-order fine grooves such as the diffraction grating 21.

  The hybrid lens 1 described above is provided with the resins 5 and 7 on both surfaces of the glass 3, but may be configured such that the resin is provided only on one surface of the glass 3. In this case, fine unevenness 9 may be formed on the other surface of the glass 3 on which no resin is provided, or the fine unevenness 9 is not formed and becomes a smooth surface (for example, a flat surface). It may be.

  Moreover, although the hybrid lens 1 is a biconvex lens, the hybrid lens 1 may be a planoconvex lens, a meniscus convex lens, a biconcave lens, a planoconcave lens, or a meniscus concave lens. Furthermore, in an optical element such as a filter, the boundary between the glass and the resin may be formed in a fine uneven shape having a period smaller than the wavelength of light.

  That is, the hybrid lens 1 includes a first material that transmits light and a second material that transmits light (a material different from the first material in optical characteristics such as a refractive index and an Abbe number). The optical element may be configured as an optical element in which the boundary between the materials is formed in a fine uneven shape having a period smaller than the wavelength of light.

1 Hybrid lens 3 Glass 5, 7 Resin 9 Concavity and convexity 23 Mold

Claims (5)

In the hybrid lens composed of glass and resin,
A hybrid lens, wherein the boundary between the glass and the resin is formed in a fine uneven shape having a period smaller than the wavelength of light. Glass whose surface is constructed in a moth-eye structure;
A resin that adheres to the surface of the glass and covers the glass;
A hybrid lens characterized by comprising: Glass in which each surface perpendicular to the optical axis is formed in fine irregularities with a period smaller than the wavelength of transmitted light;
A first resin that is in close contact with the glass and provided integrally with the glass on one surface of the glass that is formed in a fine concavo-convex shape;
A second resin that is in close contact with the glass and provided integrally with the glass on the other surface of the glass that is formed in a fine uneven shape;
A hybrid lens characterized by comprising: A fine unevenness forming step of forming fine unevenness on the surface of the glass with a period smaller than the wavelength of light transmitted through the glass;
Using a resin mold, a resin installation step of providing a resin on the surface on which fine irregularities of the glass are formed;
A method for manufacturing a hybrid lens, comprising: In an optical element composed of a first material that transmits light and a second material that transmits light,
The optical element is characterized in that the boundary between the materials is formed in a fine uneven shape having a period smaller than the wavelength of light.

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