JP2008241838A - Compound lens and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound lens capable of facilitating the determination of an optical axis alignment, and to provide a method of manufacturing the same. <P>SOLUTION: The compound lens 1 is composed of a first lens 2 and a second lens 2. The first lens 2 is composed of a first lens effective part 11 and a first flange 12. The second lens 3 is composed of a second lens effective part 31, a second flange 32, and a cylindrical part 33. A first groove 16 serving as a first marker 15 is formed in the first flange part 12 of the first lens 2. A second groove 37 serving as a second marker 36 is formed in the cylindrical part 33 of the second lens 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a compound lens and a manufacturing method thereof, and more particularly to a compound lens in which another lens is bonded to one lens and a manufacturing method thereof.

  In recent years, with the enhancement of functions of optical devices and the like, various lenses have been required for lenses used in the optical system. One lens that meets such demand is a compound lens. The compound lens refers to a lens in which two or more lenses are joined or arranged with an air gap interposed therebetween. In such a composite lens, further accuracy is required for alignment (optical axis alignment) and tilt adjustment when assembling each lens due to miniaturization of optical elements.

Patent Document 1 is one of documents that disclose a method for manufacturing such a compound lens. In the manufacturing method disclosed in the same document, first, one of the two lenses has a cylindrical projecting portion on the outer peripheral portion thereof, and an inner projecting portion is formed on the inner peripheral surface of the projecting portion. Is formed. The other lens is formed with a cylindrical projecting portion that projects in a cylindrical shape on the outer periphery thereof. Then, a composite lens is manufactured by fitting and bonding the front end surface of the inner projecting portion of one lens to the outer peripheral surface of the cylindrical projecting portion of the other lens.
Japanese Patent No. 30627760

  However, the conventional compound lens manufacturing method has the following problems. In the manufacturing method disclosed in Patent Document 1, the compound lens is formed by fitting and bonding the front end surface of the inner projecting portion of one lens to the outer peripheral surface of the cylindrical protruding portion of the other lens. . After bonding, in order to determine whether or not the compound lens has predetermined optical characteristics, it is necessary to determine whether or not the optical axis of one lens matches the optical axis of the other lens. Done. That is, eccentricity measurement is performed.

  In the eccentricity measurement, a predetermined optical measuring instrument is used to irradiate predetermined light on one lens surface of one lens, reflect the light and collect the light, and apply predetermined light to the other lens surface. It is determined whether or not the position of light that is irradiated, reflected, and collected is on the same axis. That is, in the eccentricity measurement, it is necessary to perform measurement twice for one lens. Therefore, the compound lens has a problem that it takes time to measure the eccentricity as the number of lenses increases. Moreover, the optical measuring instrument for measuring eccentricity is expensive.

  The present invention has been made to solve the above-mentioned problems, and one object is to provide a compound lens that can easily determine the optical axis alignment, and the other object is to provide such a lens. It is to provide a method for manufacturing a compound lens.

  The compound lens according to the present invention is a compound lens in which a plurality of lenses are joined, and includes a first lens, a first marker, a second lens, and a second marker. The first lens has a first lens effective portion and a first outer peripheral portion formed on the outer periphery of the first lens effective portion. The first marker is formed in a predetermined region centered on the first optical axis of the first lens effective portion on either the incident side or the emission side in the first outer peripheral portion of the first lens. . The second lens has a second lens effective portion and a second outer peripheral portion formed on the outer periphery of the second lens effective portion. The second marker is formed in a predetermined region centered on the second optical axis of the second lens effective portion on one side of the second outer peripheral portion of the second lens, and the first lens and the second lens are joined. In this state, the first marker is located at a distance.

  According to this configuration, the first marker formed around the first optical axis of the first lens and the second marker formed around the second optical axis of the second lens are the first lens and the first lens. In a state where the two lenses are joined, they are positioned at a distance from each other on either the incident side or the emission side. Accordingly, by measuring the distance between the first marker and the second marker at a predetermined position in the circumferential direction, the positional deviation between the first optical axis of the first lens and the second optical axis of the second lens can be easily performed. Judgment can be made.

  As a more specific structure, it is preferable that the first outer peripheral portion on which the first marker is formed includes a first flange portion, and the second outer peripheral portion on which the second marker is formed is a first portion facing the first flange portion. 2 flange portions, extending from the second flange portion in the first optical axis direction, separating the second flange portion from the first flange portion, and spaced from the outer edge of the first flange portion from the circumferential direction. It is preferable to include a cylindrical portion positioned so as to face each other.

  In the first flange portion, the second flange portion, and the cylindrical portion, the second optical axis of the second lens is aligned with the first optical axis of the first lens in a state where the first lens is fixed to the predetermined holding portion. It is preferable that the first outer peripheral portion and the second outer peripheral portion are set to dimensions that do not interfere with each other based on the movement allowance of the second lens.

  As a result, when the second optical axis of the second lens is aligned with the first optical axis of the first lens, the second lens is buffered by the first lens, and the optical axis is already aligned with the predetermined holding portion. It is possible to prevent the first lens from being displaced.

  In order to easily measure the distance between the first marker and the second marker, the second marker is formed on one side of the cylindrical portion, and the first marker is formed on one side of the first flange portion. It is preferable.

  Furthermore, in order to measure the optical axis alignment between the first optical axis and the second optical axis more accurately, the first marker and the second marker are preferably annular.

  As a more specific structure of the first marker and the second marker, each of the first marker and the second marker is preferably formed as a groove having a side wall surface.

  In order to perform the optical axis alignment of the first optical axis of the first lens and the second optical axis of the second lens using the groove, the side wall surface is an inclined surface, and the inclined angle of the inclined surface is 45 ° or more. It is preferable that it is set.

  The first lens has a first inclined surface in a region different from the first marker so as to surround the first optical axis from the circumferential direction at a predetermined distance from the first optical axis. The second inclined surface is preferably formed in a region different from the second marker so as to surround the second optical axis from the circumferential direction at a predetermined distance from the second optical axis.

  Thereby, the optical axis alignment of the 1st optical axis of a 1st lens and the 2nd optical axis of a 2nd lens can be performed using a 1st inclined surface and a 2nd inclined surface.

  Further, in a portion of at least one of the first lens and the second lens facing the other lens, a predetermined adhesive that joins the first lens and the second lens is directed toward the center of the one lens. It is preferable that an inflow prevention portion for preventing the inflow is formed.

  Thereby, it can prevent that the quality of a 1st lens or a 2nd lens is impaired by an adhesive agent.

  The compound lens manufacturing method according to the present invention includes a first lens in which a first marker and a first inclined surface are formed around a first optical axis, and a second marker and a second inclined surface around a second optical axis. A method of manufacturing a compound lens by manufacturing a compound lens by bonding a plurality of lenses including the second lens formed with the following lens, and includes the following steps. The first lens is placed on the lower lens holding portion having a predetermined center axis. While either one of the lower lens holding portion and the upper lens holding portion disposed above the lower lens holding portion is in contact with the first inclined surface of the first lens, the first lens is moved from above by the upper lens holding portion. By pressing, the first optical axis of the first lens is aligned with the central axis (first alignment step). With the first optical axis aligned with the central axis, the first lens is held by the lower lens holding portion, and a predetermined adhesive for bonding to the second lens is applied to the first lens. The second lens is placed on the lower lens holding portion while the first lens is held on the lower lens holding portion, and either the lower lens holding portion or the upper lens holding portion is in contact with the second inclined surface of the second lens. Then, the second lens is pressed from above by the upper lens holding portion, so that the second optical axis of the second lens is aligned with the central axis (second alignment step). The first lens and the second lens are joined by curing the adhesive in a state where the second optical axis of the second lens is aligned with the central axis. The distance between the first marker and the second marker is measured at a plurality of predetermined positions in the circumferential direction of the joined first lens and second lens.

  According to this method, the first marker formed around the first optical axis of the first lens and the second optical axis of the second lens are formed at a plurality of predetermined positions in the circumferential direction of the lens. By measuring the distance to the second marker, it is possible to easily confirm the optical axis alignment between the first optical axis of the first lens and the second optical axis of the second lens.

  As one more specific method of aligning the first optical axis and the second optical axis, in the first alignment step, an inclined surface formed in a region different from the region where the first marker is positioned as the first inclined surface. In the second alignment step, an inclined surface formed in a region different from the region where the second marker is positioned is preferably applied as the second inclined surface.

  As another more specific method for aligning the first optical axis and the second optical axis, in the first alignment step, the inclined surface of the first groove formed as the first marker is applied as the first inclined surface. In the second alignment step, the inclined surface of the second groove formed as the second marker is preferably applied as the second inclined surface.

Embodiment 1
First, the compound lens 1 according to Embodiment 1 is shown in FIG. As shown in FIG. 1, the compound lens 1 is formed by a first lens 2 and a second lens 3. The first lens 2 includes a first lens effective portion 11 and a first flange portion 12, and the first flange portion 12 is formed on the outer periphery of the first lens effective portion 11.

  The second lens 3 includes a second lens effective part 31, a second flange part 32, and a cylindrical part 33. The second flange portion 32 is formed on the outer periphery of the second lens effective portion 31. The cylindrical portion 33 is formed so as to protrude from the outer edge portion of the second flange portion 32 in the direction of the optical axis 70.

  In this compound lens 1, the first lens 2 and the second lens 3 are joined to each other in such a manner that the first flange portion 12 of the first lens 2 is received in the inner region of the cylindrical portion 33 of the second lens 3. Yes. As will be described later, in order to determine, for example, with a microscope, whether or not the optical axis 70 of the first lens 2 and the optical axis 71 of the second lens 3 coincide with each other, the first marker 2 has a first marker. 15 is formed, and the second lens 3 is formed with a second groove 37 as a second marker 36.

  As shown in FIG. 2, the first groove 16 as the first marker 15 is formed along the outer edge on the end surface 13 (surface orthogonal to the optical axis) of the first flange portion 12 around the optical axis 70. (The front half is not shown). In the first groove 16, an inclined surface 16a having a predetermined angle is formed. As shown in FIG. 3, the second groove 37 as the second marker 36 is formed along the inner edge on the end surface 34 (surface orthogonal to the optical axis) of the cylindrical portion 33 with the optical axis 71 as the center. (The front half is not shown). In the second groove 37, an inclined surface 37a having a predetermined angle is formed.

  As shown in FIGS. 1 and 4, when the first lens 2 and the second lens 3 are joined, the outer peripheral surface 14 of the first flange portion 12 and the inner peripheral surface 35 of the cylindrical portion 33 are separated by a distance ( They are opposed to each other with a gap 50). The first groove 16 is located inside the gap 50, and the second groove 37 is located outside the gap 50. The distance L1 from the bottom of the first groove 16 to the outer peripheral surface 14 is, for example, about 200 μm, and the distance L2 from the bottom of the second groove 37 to the inner peripheral surface 35 is also about 200 μm.

  As will be described later, the optical axis alignment is confirmed by measuring the distance between the first groove 16 and the second groove 37 of the cemented compound lens 1. Further, by using the inclined surface 16a of the first groove 16 and the inclined surface 37a of the second groove 37, the optical axis of the first lens 2 is aligned with the central axis of the lower lens holding portion, or the light of the second lens 3 is used. When the axis is aligned with the central axis of the lower lens holding portion, the inclination angle θ of the inclined surfaces 16a and 37a is preferably 45 ° or more. This is because when the tilt angle θ is less than 45 °, the optical axis cannot be satisfactorily aligned.

  Further, as shown in FIG. 5, in order to prevent the adhesive 10 applied when the first lens 2 and the second lens 3 are joined from flowing out to the lens effective portion 11 to deteriorate the quality of the lens, The first lens 2 is provided with a first protrusion 17, and the second lens 3 is provided with a second protrusion 38. The first protrusion 17 and the second protrusion 38 are preferably formed over the entire circumference so as to surround the lens effective portion 11, but if the inflow of the adhesive 10 can be prevented, the adhesive 10 You may provide only in the predetermined | prescribed circumferential direction part apply | coated.

  Further, the first lens 2 and the second lens 3 are set to predetermined dimensions so as not to contact each other when the first lens 2 and the second lens 3 are joined. That is, as shown in FIG. 6, at each part of the first lens 2 and the second lens 3, the optical axis of the second lens 3 with respect to the optical axis 70 of the first lens 2 on a predetermined lens holding portion 5. The dimensions are set and arranged in consideration of the movement allowance (imaginary lines 61 and 62) of the second lens 3 at the time of matching.

  For example, the first protrusion 17 of the first lens 2 and the second protrusion 38 of the second lens 3 are formed so as to have different radial positions (distance from the optical axis 70). In addition, the length T1 of the tubular portion 33 is set so that the second flange portion 3 of the second flange portion 3 is not in contact with the first flange portion 12 so as to be separated from the first flange portion 12 by a predetermined distance S1. Has been. Furthermore, in order not to make the inner part of the cylindrical part 33 contact the outer peripheral part of the first flange part 12, the inner diameter T2 of the cylindrical part 33 is separated from the outer peripheral part of the first flange part 12 by a distance (distance D). Is set. The compound lens 1 according to the present embodiment is configured as described above.

  Next, an example of a method for manufacturing the above-described compound lens will be described. In this compound lens manufacturing method, optical axis alignment is performed using the inclined surface 16 a of the first groove 16 as the first marker 15 and the inclined surface 37 a of the second groove 37 as the second marker 36. First, alignment between the optical axis of the first lens and the central axis of the lower lens holding portion is performed. As shown in FIG. 7, annular protrusions 5 a and 5 b are formed on the upper surface of the lower lens holding portion 5. The protrusion 5a is formed with a predetermined radius with respect to the central axis 6 so that the protrusion 5a corresponds to the first groove 16 of the first lens 2 and the protrusion 5b corresponds to the second groove 37 of the second lens 3. ing.

  First, the first lens 2 is approximately aligned with the lower lens holding portion 5 so that the projection 5a fits into the first groove 16 of the first lens 2, and the first lens 2 is moved to the lower lens holding portion. Place on top of 5. Then, the protrusion 5 a comes into contact with the inclined surface 16 a of the first groove 16, and the first lens 2 is inclined with respect to the lower lens holding portion 5. Next, as shown in FIG. 8, the upper lens holding portion 7 is lowered and brought into contact with the first flange portion 12 of the first lens 2. At this time, since the first lens 2 is inclined with respect to the lower lens holding portion 5 (angle α1), the upper lens holding portion 7 is one of the entire circumferences of the first flange portion 12 as shown in FIG. It contacts only the part 12a.

  Actually, when the first lens 2 is inclined with respect to the lower lens holding portion 5, in FIG. 9, the upper lens holding portion 7 and the lower lens holding portion 5 with the first lens 2 as a reference (horizontal). Therefore, the upper lens holding part 7 and the lower lens holding part 5 are shown tilted with respect to the first lens 2 (angle α1). The same applies to FIGS. 11 and 13 described later.

  On the other hand, the annular protrusion 5 a comes into contact with a position corresponding to the inclination of the first lens 2 on the inclined surface 16 a of the first groove 16. A dotted line 80 indicates the contact portion. In the figure, a dotted line 81 indicates the position of the bottom 16b of the first groove 16, and is located at a certain distance from the optical axis 70 (center O) of the first lens 2. Depending on the state in which the first lens 2 is placed on the lower lens holding portion 5 or the inclination angle of the inclined surface 5a of the first groove 5, the protrusion 5a does not contact the entire circumference of the inclined surface 16a, and is partially In some cases, it is only in contact.

  Next, as shown in FIG. 10, the upper lens holding part 7 is gradually lowered. If it does so, the 1st lens 2 will be pressed from the upper part, the projection part 5a which was contacting the inclined surface 16a will slide relatively with respect to the inclined surface 16a, and the inclination of the 1st lens 2 will become loose. As shown in FIG. 11, when the inclination becomes gentle (angle α2 <α1), the portion 12b (circumferential portion) where the upper lens holding portion 7 contacts the first flange portion 12 increases.

  On the other hand, the annular protrusion 5 a comes into contact with a position corresponding to the more gentle inclination of the first lens 2 on the inclined surface 16 a of the first groove 16. A dotted line 80 indicates the contact portion. In FIG. 9, a two-dot chain line 85 indicates a relative inclination of the lower lens holding unit 5 or the upper lens holding unit 7 with respect to the first lens 2 in the state shown in FIG.

  Next, when the upper lens holding portion 7 is further lowered and the first lens 2 is pressed from above, the protrusion 5a that has been in contact with the inclined surface 16a slides relative to the inclined surface 16a, and the first lens The slope of 2 becomes even gentler. And finally, as shown in FIG. 12, the inclination of the 1st lens 2 is lose | eliminated. As shown in FIG. 13, when the inclination of the first lens 2 disappears, the upper lens holding portion 7 comes into contact over the entire circumference 12 c of the first flange portion 12.

  On the other hand, the annular protrusion 5 a comes into contact with the circumference of a predetermined distance from the center O on the inclined surface 16 a of the first groove 16. A dotted line 80 indicates the contact portion. In FIG. 9, a two-dot chain line 85 indicates a relative inclination of the lower lens holding unit 5 or the upper lens holding unit 7 with respect to the first lens 2 in the state shown in FIG. 9, and a two-dot chain line 86 is shown in FIG. The relative inclination of the lower lens holding part 5 or the upper lens holding part 7 with respect to the first lens 2 in the state shown in FIG. Thus, as shown in FIG. 14, the center axis 6 of the lower lens holding portion 5 and the optical axis 70 of the first lens 2 are aligned.

  Next, the first lens 2 is vacuum-adsorbed to the lower lens holding unit 5 in this state. Next, as shown in FIG. 15, the upper lens holding portion 7 is raised and a predetermined ultraviolet curing adhesive 10 is applied to the first flange portion 12 of the first lens 2. Next, alignment between the optical axis of the second lens 3 and the central axis of the lower lens holding portion 5 is performed.

  As shown in FIG. 16, first, as in the case of the first lens 2, the second lens 3 with respect to the lower lens holding portion 5 so that the protrusion 5 b fits into the second groove 37 of the second lens 3. The second lens 3 is placed on the lower lens holding portion 5. Then, the protruding portion 5 b comes into contact with the inclined surface 37 a of the second groove 37, and the second lens 3 is inclined with respect to the lower lens holding portion 5.

  Next, as shown in FIG. 17, the upper lens holding portion 7 is lowered and brought into contact with the second flange portion 32 of the second lens 3. Then, as in the case of the first lens 2, the upper lens holding portion 7 is gradually lowered, and after the same state as shown in FIGS. 9, 11, and 13, the upper lens holding portion 7 The two flange portions 32 come in contact over the entire circumference. Further, the annular protrusion 5 b comes into contact with the circumference of a predetermined distance from the center (optical axis 71) on the inclined surface 37 a of the second groove 37. Thus, as shown in FIG. 18, the optical axis 71 of the second lens 3 and the central axis 6 of the lower lens holding portion 5 are aligned.

  In this alignment step, as described above, the first lens 2 and the second lens 3 are set to predetermined dimensions so as not to contact each other, so that the second flange portion of the second lens 3 is set. 32 and the cylindrical portion 33 buffer the first flange portion 12 of the first lens 2 to prevent the already aligned first lens 2 from being displaced from the lower lens holding portion 5. it can.

  Next, as shown in FIG. 19, the adhesive 10 is cured by irradiating ultraviolet rays from above the second lens 3 to join the first lens 2 and the second lens 3 together. After the adhesive 10 is cured, the upper lens holding portion 7 is raised, and the joined first lens 2 and second lens 3 are removed from the lower lens holding portion 5. In this way, as shown in FIG. 20, the composite lens 1 in which the first lens 2 and the second lens 3 are cemented is completed.

  Next, it is evaluated whether or not the optical axis 70 of the first lens 2 and the optical axis 71 of the second lens 3 of the completed compound lens 1 coincide with each other. As shown in FIG. 21, the first groove 16 as the first marker and the second groove 37 as the second marker for, for example, four measurement points K <b> 1 to K <b> 4 in the circumferential direction of the entire circumference of the compound lens 1. The distances D1 to D4 are measured with a microscope. As the distance to be measured, for example, the distance between the bottom of the first groove 16 and the bottom of the second groove 37, the distance between the outer edge of the inclined surface of the first groove 16 and the inner edge of the inclined surface of the second groove 37, etc. Can be measured.

  As a result of the measurement, if the distances D1 to D4 are within a desired value range, the optical axis 70 of the first lens 2 and the optical axis 71 of the second lens 3 coincide with each other, and the optical axis alignment is performed well. To be judged. On the other hand, for example, as shown in FIG. 22, in the compound lens 1 in which the distance D1 of the measurement point K1 is larger than the desired value and the distance D3 of the measurement point K3 is smaller than the desired value, the optical axis 70 of the first lens 2 is obtained. And the optical axis 71 of the second lens 3 do not coincide with each other, and it is determined that the optical axis is not properly aligned.

  Thus, the compound lens 1 determined that the optical axis alignment of the first lens 2 and the second lens 3 has been satisfactorily performed is sent to the next process as a finished product. On the other hand, compound lenses that are determined not to have been optically aligned are rejected as defective products.

  In the compound lens manufacturing method described above, the first marker 2 is formed on the first lens 2 with the optical axis 70 as the center, and the second marker 3 is formed on the second lens 3 with the optical axis 71 as the center. In a state where the first lens 2 and the second lens 3 are joined, the distance between the first marker and the second marker at a predetermined position in the circumferential direction is measured with a microscope. As a result, it is possible to determine whether the optical axis alignment is good or not simply by determining whether or not each measured distance is within a predetermined value range. Therefore, it is not necessary to measure the condensing position using the optical measuring instrument, and it is possible to easily determine whether or not the optical axis is aligned.

  In addition, in a state where the first lens 2 and the second lens 3 are joined, in the vicinity of the gap between the first lens 2 and the second lens 3 (the gap between the first flange portion 12 and the cylindrical portion 33). The first lens 16 is formed with a first groove 16 as a first marker, and the second lens 3 is formed with a second groove 37 as a second marker so as to be positioned. Accordingly, the measurement points K1 to K4 can be observed with a microscope at a relatively high magnification, and the accuracy of optical axis alignment can be improved by increasing the distance measurement accuracy.

  Further, the first groove 16 is provided with an inclined surface 16a, the second groove 37 is provided with an inclined surface 37a, and the lower lens holding portion 5 has an annular protrusion 5a that contacts the inclined surfaces 16a, 37a, 5b is provided. As a result, the first lens 2 and the second lens 3 placed on the lower lens part holding part 5 are pressed by the upper lens holding part 7 from above in a mode of contacting the annular protrusions 5a and 5b. The annular protrusions 5a and 5b relatively slide on the inclined surfaces 16a and 37a, and the inclinations of the first lens 2 and the second lens 3 gradually become gentle, and finally the optical axis 70 of the first lens 2 and The center axis 6 of the lower lens holding part 5 can be matched, and the optical axis 71 of the second lens 3 and the center axis 6 of the lower lens holding part 5 can be matched.

  That is, by using the inclined surface 16a of the first groove 16 as the first marker and the inclined surface 37a of the second groove 37 as the second marker, the optical axes 70, respectively of the first lens 2 and the second lens 3, respectively. 71 and the central axis 6 of the lower lens holding portion 5 can be aligned.

  Further, at each part of the first lens 2 and the second lens 3, a movement allowance (imaginary line 61, imaginary line 61, 62) is set in consideration (see FIG. 6). Thus, when the optical axis 71 of the second lens is aligned with the central axis 6 of the lower lens holding unit 5, the optical axis 70 of the first lens 2 that has already been aligned is separated from the central axis 6 of the lower lens holding unit 5. It is possible to prevent the shift.

  The first lens 2 is provided with a first protruding portion 17 so as to surround the first lens effective portion 11 (or the second lens effective portion 31), and the second lens 3 is also provided with the second lens effective portion 31 ( Or the 2nd protrusion part 38 is provided so that the 1st lens effective part 11) may be surrounded. Thereby, the adhesive 10 applied when the first lens 2 and the second lens 3 are joined is prevented from flowing out to the lens effective portion 11, and the quality of the first lens 2 or the second lens 3 is impaired. Can be prevented.

Embodiment 2
Here, another example of a method of manufacturing a compound lens using the first lens and the second lens described above will be described. In this compound lens manufacturing method, as shown in FIG. 23, the optical axes 70 and 71 are aligned using the inclined surface 18 of the first lens 2 and the inclined surface 39 of the second lens 3. First, alignment between the optical axis 70 of the first lens and the central axis of the lower lens holding portion is performed.

  First, as shown in FIG. 24, the surface of the first flange portion 12 of the first lens 2 opposite to the surface on which the first marker is formed is in contact with the upper surface of the lower lens holding portion 5. One lens 2 is placed on the lower lens holder 5. This surface of the first flange portion 12 is in one plane, and the first lens 2 is placed on the lower lens holding portion 5 almost horizontally. Therefore, in this state, the optical axis 70 and the central axis 6 do not coincide with each other, but the first lens 2 and the lower lens holding part 5 are in an arrangement relationship in which the optical axis 70 and the central axis 6 are substantially parallel.

  Next, the upper lens holding part 7 is gradually lowered. The central axis 9 of the upper lens holding part 7 is aligned with the central axis 6 of the lower lens holding part 5 in advance. Then, as shown in FIG. 25, the upper lens holding portion 7 comes into contact only with a part of the inclined surface 18 of the first lens 2 on the side where the optical axis 70 is shifted with respect to the central axes 6 and 9. (Contact part 21). When the upper lens holding portion 7 is further lowered, the first lens 2 slides toward the side where the upper lens holding portion 7 is not in contact (arrow 22).

  As shown in FIG. 26, when the first lens 2 is slid, the circumferential portion where the upper lens holding portion 7 comes into contact with the inclined surface 18 of the first lens 2 increases (contact portion 21). When the upper lens holding portion 7 is further lowered, the first lens 2 further slides in the direction indicated by the arrow 22. When the upper lens holding portion 7 is further lowered, the upper lens holding portion 7 finally comes into contact with the inclined surface 18 of the first lens 2 over the entire circumference as shown in FIG. A state is reached (contact portion 21). Thus, the optical axis 70 of the first lens 2 is aligned with the central axis 9 of the upper lens holding portion 7 and the central axis 6 of the lower lens holding portion 5.

  Next, as shown in FIG. 28, in this state, the first lens 2 is vacuum-sucked to the upper lens holding portion 7, and the upper lens holding portion 7 is raised together with the first lens 2. Next, as shown in FIG. 29, the second lens 3 is placed on the lower lens holding portion 5 in such a manner that the inner end portion of the lower lens holding portion 5 contacts the inclined surface 39 of the second lens 3. To do. In this state, the optical axis 71 of the second lens 3 is not yet coincident with the central axis 6 of the lower lens holding portion 5, and the second lens 3 is tilted. Next, a predetermined ultraviolet curable adhesive 10 is applied to the second flange portion 32 of the second lens 3.

  Next, alignment between the optical axis 71 of the second lens 3 and the central axis 6 of the lower lens holding portion 5 is performed. First, as shown in FIG. 30, the upper lens holding portion 7 is lowered together with the first lens 2, and the upper lens holding portion 7 is brought into contact with the cylindrical portion 33 of the second lens 3. At this time, since the second lens 3 is inclined with respect to the lower lens holding portion 5 (angle β1), the upper lens holding portion 7 has the entire circumference of the cylindrical portion 33 of the second lens 3 as shown in FIG. It contacts only a part 33a. On the other hand, the lower lens holding unit 5 comes into contact with a position corresponding to the inclination of the second lens 3 on the inclined surface 39 of the second lens 3. A solid line 87 indicates the contact portion.

  Actually, when the second lens 3 is inclined with respect to the lower lens holding portion 5, in FIG. 31, the upper lens holding portion 7 and the lower lens holding portion 5 with the second lens 3 as a reference (horizontal). Therefore, the upper lens holding portion 7 and the lower lens holding portion 5 are shown tilted with respect to the second lens 3. The same applies to FIGS. 33 and 35 described later.

  Next, as shown in FIG. 32, the upper lens holding portion 7 is gradually lowered. Then, the second lens 3 is pressed from above, and the lower lens holding portion 5 that has been in contact with the inclined surface 39 slides relative to the inclined surface 39, so that the inclination of the second lens 3 becomes gentle. Become. As shown in FIG. 33, when the inclination becomes gentle (angle β2 <β1), the portion 33b (circumferential portion) where the upper lens holding portion 7 contacts the cylindrical portion 33 of the second lens 3 increases.

  On the other hand, the lower lens holding portion 5 comes into contact with a position corresponding to the more gentle inclination of the second lens 3 on the inclined surface 39 of the second lens 3. A solid line 87 indicates the contact portion. In the figure, a two-dot chain line 85 indicates a relative inclination of the lower lens holding portion 5 or the upper lens holding portion 7 with respect to the second lens 3 in the state shown in FIG.

  Next, when the upper lens holding portion 7 is further lowered and the second lens 3 is pressed from above, the lower lens holding portion 5 that has been in contact with the inclined surface 39 slides relative to the inclined surface 39, and 2 The inclination of the lens 3 becomes further gentle. As shown in FIG. 34, the inclination of the second lens 3 finally disappears. As shown in FIG. 35, when the inclination of the second lens 3 is eliminated, the upper lens holding portion 7 comes into contact over the entire circumference 33c of the cylindrical portion 33 of the second lens 3.

  On the other hand, the lower lens holding portion 5 comes into contact with the circumference of a predetermined distance from the center O on the inclined surface 39 of the second lens 3. A solid line 87 indicates the contact portion. In the figure, a two-dot chain line 85 indicates a relative inclination of the lower lens holding unit 5 or the upper lens holding unit 7 with respect to the second lens 3 in the state shown in FIG. The relative inclination of the lower lens holding part 5 or the upper lens holding part 7 with respect to the second lens 3 in the state shown in FIG. Thus, as shown in FIG. 36, the center axis 6 of the lower lens holding portion 5 and the optical axis 71 of the second lens 3 are aligned.

  In this alignment step, as described above, the first lens 2 and the second lens 3 are set to predetermined dimensions so as not to contact each other, so that the second flange portion of the second lens 3 is set. 32 and the cylindrical portion 33 buffer the first flange portion 12 of the first lens 2 to prevent the already aligned first lens 2 from being displaced from the lower lens holding portion 5. it can.

  Next, as shown in FIG. 37, the adhesive 10 is cured by irradiating ultraviolet rays from above the first lens 2 to bond the first lens 2 and the second lens 3 together. After the adhesive 10 is cured, the upper lens holding portion 7 is raised, and the joined first lens 2 and second lens 3 are removed from the lower lens holding portion 5. Thus, as shown in FIG. 38, the composite lens 1 in which the first lens 2 and the second lens 3 are cemented is completed.

  Next, it is evaluated whether or not the optical axis 70 of the first lens 2 and the optical axis 71 of the second lens 3 of the completed compound lens 1 coincide with each other. As shown in FIG. 39, for example, the four measurement points K1 to K4 in the circumferential direction of the entire circumference of the compound lens 1 can be measured between the first marker 15 and the second marker 36 by the same method as described above. The distance is measured with a microscope.

  As a result of the measurement, if the distances D1 to D4 at the measurement points K1 to K4 are within a desired value range, the optical axis 70 of the first lens 2 and the optical axis 71 of the second lens 3 coincide with each other, and the optical axis It is determined that the alignment is performed well (see FIG. 21). On the other hand, for example, in the compound lens 1 in which the distance D1 of the measurement point K1 is larger than the desired value and the distance D3 of the measurement point K3 is smaller than the desired value, the optical axis 70 of the first lens 2 and the second lens 3 It does not coincide with the optical axis 71, and it is determined that the optical axis is not aligned well (see FIG. 22).

  In the manufacturing method of the compound lens 1 described above, the first marker 15 formed with the optical axis of the first lens 2 as the center and the optical axis of the second lens 3 as the center, as in the method of manufacturing the compound lens described above. By measuring the distance at a predetermined position in the circumferential direction with respect to the formed second marker 36, it is possible to easily determine whether or not the optical axis is aligned as compared with the conventional measurement method.

  Further, the first marker 15 and the second marker 36 lens 3 are formed in the vicinity of the gap between the first lens 2 and the second lens 3 (the gap between the first flange portion 12 and the cylindrical portion 33). Thus, the measurement point can be observed with a microscope at a relatively high magnification, and the accuracy of optical axis alignment can be improved by increasing the distance measurement accuracy.

  Further, in the first lens 2 and the second lens 3, the dimensions of each part are set in consideration of the movement allowance (imaginary lines 61, 62) of the second lens 3 when the optical axis 71 of the second lens 3 is aligned. Thus, when the optical axis 71 of the second lens 3 is aligned with the central axis 6 of the lower lens holding unit 5, the optical axis 70 of the first lens 2 that has already been aligned is aligned with the upper lens holding unit 7. Deviation from the central axis 6 can be prevented.

  Then, the first and second projections 17 provided on the first lens 2 and the second projection 38 provided on the second lens 3 are applied when the first lens 2 and the second lens 3 are joined. It is possible to prevent the agent 10 from flowing out to the lens effective portion 31 and prevent the quality of the first lens 2 or the second lens 3 from being impaired.

  In the compound lens 1 described above, the method of joining the two lenses of the first lens 2 and the second lens 3 has been described as an example, but the number of lenses to be joined is not limited to two. As shown in FIG. 40 or FIG. 41, three lenses may be cemented. When three lenses are joined, the composite lens 1 can be manufactured by joining the first lens 2 and the second lens 3 and further joining the third lens 4. Even when the third lens 4 is joined, it is possible to easily determine whether or not the optical axis is aligned by measuring the distance between the third marker 41 of the third lens 4 and the second marker 36 of the second lens 3. Can do. Furthermore, the present invention is not limited to three, and can be applied to the case where four or more lenses are joined.

  In each embodiment, the structure shown in FIG. 4 has been described as the first marker or the second marker. The first marker or the second marker is not limited to this shape, and for example, a structure as shown in FIGS. 42 to 45 may be adopted. In order to use the inclined surface of these first marker or second marker for optical axis alignment, the inclination angle is preferably 45 ° or more.

  The embodiment disclosed this time is an example, and the present invention is not limited to this. The present invention is defined by the terms of the claims, rather than the scope described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the cross-sectional structure and planar structure of the compound lens which concern on Embodiment 1 of this invention. FIG. 3 is a cross-sectional perspective view of a first lens in the same embodiment. In the same embodiment, it is a section perspective view of the 2nd lens. In the same embodiment, it is a partial expanded sectional view showing the 1st marker, the 1st marker, and its neighborhood. In the same embodiment, it is the elements on larger scale which show the structure which prevents the inflow of the adhesive. In the same embodiment, it is the elements on larger scale which show the structure of the outer peripheral part of the compound lens. FIG. 3 is a cross-sectional view showing a step of the method of manufacturing the composite lens shown in FIG. 1 in the same embodiment. FIG. 8 is a partial cross-sectional view showing a step performed after the step shown in FIG. 7 in the same embodiment. FIG. 9 is a diagram showing a relative positional relationship between a lower lens holding portion and an upper lens holding portion with respect to the first lens in the step shown in FIG. 8 in the embodiment. FIG. 10 is a partial cross-sectional view showing a process performed after the process shown in FIGS. 8 and 9 in the embodiment. FIG. 11 is a diagram showing a relative positional relationship between a lower lens holding portion and an upper lens holding portion with respect to a first lens in the step shown in FIG. 10 in the embodiment. FIG. 12 is a partial cross-sectional view showing a process performed after the process shown in FIGS. 10 and 11 in the embodiment. FIG. 13 is a diagram showing a relative positional relationship between the lower lens holding unit and the upper lens holding unit with respect to the first lens in the step shown in FIG. 12 in the embodiment. FIG. 13 is a cross-sectional view in the step shown in FIG. 12 in the same embodiment. FIG. 15 is a cross-sectional view showing a step performed after the step shown in FIG. 14 in the same embodiment. FIG. 16 is a cross-sectional view showing a step performed after the step shown in FIG. 15 in the same embodiment. FIG. 17 is a cross-sectional view showing a step performed after the step shown in FIG. 16 in the same embodiment. FIG. 18 is a cross-sectional view showing a step performed after the step shown in FIG. 17 in the same embodiment. FIG. 19 is a cross-sectional view showing a step performed after the step shown in FIG. 18 in the same embodiment. FIG. 20 is a cross-sectional view showing a step performed after the step shown in FIG. 19 in the same embodiment. In the same embodiment, it is a top view for demonstrating the method to judge the quality of the optical axis alignment of the combined compound lens. In the same embodiment, it is another top view for demonstrating the method to judge the quality of the optical axis alignment of the compound lens joined. It is a figure which shows the cross-section of the compound lens which concerns on Embodiment 2 of this invention. FIG. 24 is a cross-sectional view showing a step of the method of manufacturing the composite lens shown in FIG. 23 in the embodiment. FIG. 25 is a diagram showing a relative positional relationship between the lower lens holding portion and the upper lens holding portion with respect to the first lens in a step performed after the step shown in FIG. 24 in the embodiment. FIG. 26 is a diagram showing a relative positional relationship between the lower lens holding portion and the upper lens holding portion with respect to the first lens in a step performed after the step shown in FIG. 25 in the embodiment. FIG. 27 is a diagram showing a relative positional relationship between the lower lens holding portion and the upper lens holding portion with respect to the first lens in a step performed after the step shown in FIG. 26 in the embodiment. FIG. 28 is a cross-sectional view showing a step performed after the step shown in FIG. 27 in the same embodiment. FIG. 29 is a cross-sectional view showing a step performed after the step shown in FIG. 28 in the same embodiment. FIG. 30 is a cross-sectional view showing a step performed after the step shown in FIG. 29 in the same embodiment. FIG. 31 is a diagram showing a relative positional relationship between a lower lens holding portion and an upper lens holding portion with respect to a second lens in the step shown in FIG. 30 in the embodiment. FIG. 32 is a cross-sectional view showing a step performed after the step shown in FIGS. 30 and 31 in the same embodiment. FIG. 33 is a diagram showing a relative positional relationship between a lower lens holding portion and an upper lens holding portion with respect to a second lens in the step shown in FIG. 32 in the embodiment. FIG. 34 is a cross-sectional view showing a step performed after the step shown in FIGS. 32 and 33 in the same embodiment. FIG. 35 is a diagram showing a relative positional relationship between a lower lens holding portion and an upper lens holding portion with respect to a second lens in the step shown in FIG. 34 in the embodiment. FIG. 36 is a cross-sectional view showing a step performed after the step shown in FIGS. 34 and 35 in the same embodiment. FIG. 37 is a cross-sectional view showing a step performed after the step shown in FIG. 36 in the same embodiment. FIG. 38 is a cross-sectional view showing a step performed after the step shown in FIG. 37 in the same embodiment. In the same embodiment, it is a top view for demonstrating the method to judge the quality of the optical axis alignment of the combined compound lens. It is sectional drawing which shows the structure of the compound lens which concerns on one modification. It is sectional drawing which shows the structure of the compound lens which concerns on another modification. It is a fragmentary sectional view showing the 1st modification of the 1st marker or the 2nd marker concerning each embodiment. It is a fragmentary sectional view showing the 2nd modification of the 1st marker or the 2nd marker concerning each embodiment. It is a fragmentary sectional view showing the 3rd modification of the 1st marker or the 2nd marker concerning each embodiment. It is a fragmentary sectional view showing the 4th modification of the 1st marker or the 2nd marker concerning each embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Compound lens, 2 1st lens, 3 2nd lens, 4 3rd lens, 5 Lower lens holding part, 6 Central axis, 7 Upper lens holding part, 9 Central axis, 10 Adhesive, 11 1st lens effective part, 12 1st flange part, 13 End face, 14 Outer peripheral surface, 15 1st marker, 16 1st groove | channel, 16a Inclined surface, 16b Bottom, 17 1st protrusion part, 18 Inclined surface, 21 Contact part, 22 Arrow, 31 2nd Effective lens portion, 32 second flange portion, 33 cylindrical portion, 34 end surface, 35 peripheral surface, 36 second marker, 37 second groove, 37a inclined surface, 37b bottom, 38 second protruding portion, 39 inclined surface, 41 3rd marker, 50 gap.

Claims (12)

A compound lens in which a plurality of lenses are joined,
A first lens having a first outer peripheral portion formed on an outer periphery of the first lens effective portion and the first lens effective portion;
A first marker formed in a predetermined region centered on the first optical axis of the first lens effective portion on either the incident side or the emission side of the first outer peripheral portion of the first lens When,
A second lens having a second outer peripheral portion formed on an outer periphery of the second lens effective portion and the second lens effective portion;
On the one side of the second outer peripheral portion of the second lens, the second lens is formed in a predetermined region centered on the second optical axis of the effective portion of the second lens, and the first lens and the second lens are A compound lens comprising: a second marker positioned at a distance from the first marker in a joined state. The first outer peripheral portion includes a first flange portion,
The second outer peripheral portion is
A second flange portion facing the first flange portion;
The second flange portion extends from the second flange portion in the first optical axis direction, and the second flange portion is spaced from the first flange portion, and is spaced from the outer edge of the first flange portion from the circumferential direction. And a cylindrical part positioned so as to face each other.   In the first flange portion, the second flange portion, and the cylindrical portion, the second optical axis of the second lens is aligned with the first optical axis of the first lens while the first lens is fixed to a predetermined holding portion. The compound lens according to claim 2, wherein the first outer peripheral portion and the second outer peripheral portion are set to dimensions that do not interfere with each other based on a movement allowance of the second lens when the optical axis is aligned with one optical axis. The second marker is formed on the one side of the cylindrical portion,
The compound lens according to claim 2 or 3, wherein the first marker is formed on the one side of the first flange portion.   The compound lens according to claim 1, wherein the first marker and the second marker are annular.   Each of the said 1st marker and the said 2nd marker is a compound lens in any one of Claims 1-5 formed as a groove | channel which has a side wall surface. The side wall surface is an inclined surface,
The compound lens according to claim 6, wherein an inclination angle of the inclined surface is set to 45 ° or more. In the first lens, a first inclined surface is formed in a region different from the first marker so as to surround the first optical axis from the circumferential direction at a predetermined distance from the first optical axis,
The second inclined surface is formed on the second lens so as to surround the second optical axis in a circumferential direction at a predetermined distance from the second optical axis in a region different from the second marker. The compound lens in any one of 1-7.   In a portion of at least one of the first lens and the second lens facing the other lens, a predetermined adhesive that joins the first lens and the second lens is directed toward the center of the one lens. The composite lens according to claim 1, wherein an inflow prevention portion that prevents the adhesive from flowing in is formed. A plurality of lenses including a first lens having a first marker and a first inclined surface formed with the first optical axis as a center, and a second lens having a second marker and a second inclined surface formed with the second optical axis as a center. A compound lens manufacturing method for manufacturing a compound lens by joining the lenses of:
Placing the first lens on a lower lens holding portion having a predetermined central axis;
While either one of the lower lens holding portion and the upper lens holding portion disposed above the lower lens holding portion is in contact with the first inclined surface of the first lens, the first lens is moved to the upper lens. A first alignment step of aligning the first optical axis of the first lens with the central axis by pressing from above with a holding unit;
With the first optical axis aligned with the central axis, the first lens is held by the lower lens holding portion, and a predetermined adhesive for bonding to the second lens is applied to the first lens. Process,
The second lens is placed on the lower lens holding portion in a state where the first lens is held on the lower lens holding portion, and one of the lower lens holding portion and the upper lens holding portion is placed on the second lens. A second alignment step of aligning the second optical axis of the second lens with the central axis by pressing the second lens from above with the upper lens holding portion while contacting the second inclined surface; ,
The step of bonding the first lens and the second lens by curing the adhesive in a state where the second optical axis of the second lens is aligned with the central axis. A method of manufacturing a composite lens, comprising: measuring a distance between the first marker and the second marker at a plurality of predetermined positions in the circumferential direction of the lens and the second lens. In the first alignment step, an inclined surface formed in a region different from the region where the first marker is positioned is applied as the first inclined surface,
11. The method of manufacturing a compound lens according to claim 10, wherein in the second alignment step, an inclined surface formed in an area different from an area where the second marker is located is applied as the second inclined surface. In the first alignment step, an inclined surface of the first groove formed as the first marker is applied as the first inclined surface,
11. The method of manufacturing a compound lens according to claim 10, wherein in the second alignment step, an inclined surface of a second groove formed as the second marker is applied as the second inclined surface.

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