JPWO2015174393A1 - Array lens, compound eye optical system, imaging apparatus, measurement method, evaluation method, and manufacturing method - Google Patents

Abstract

Provided are an array lens, a compound eye optical system, an imaging device, a measuring method, an evaluation method, and a manufacturing method that can accurately measure the position of the optical surface of a lens unit and can be positioned with high accuracy with respect to an object. This array lens has a plurality of lens portions arranged with different optical axes, and a flange portion connecting the plurality of lens portions, and a measurement reference first for measuring the position of the lens portion. Two reference portions are formed at a predetermined interval on the flange portion, and the first reference portion is outside the range connecting the outer circumferences of the outermost lens portions when viewed in the optical axis direction. Located in.

Description

  The present invention relates to an array lens having a plurality of lens portions, a compound eye optical system, an imaging device, a measurement method, an evaluation method, and a manufacturing method.

  2. Description of the Related Art In recent years, mobile terminals with thin imaging devices such as smartphones and tablet personal computers are rapidly spreading. However, an imaging apparatus mounted on such a thin portable terminal is required to be thin and compact while having high resolution. In order to meet such demands, we have improved the manufacturing accuracy in response to the shortening of the overall length by the optical design of the imaging lens and the accompanying increase in error sensitivity. A configuration in which an image is obtained by a combination of an imaging lens and an imaging element is insufficient, and an optical system that is different from the conventional one is expected.

  On the other hand, an optical system called a compound eye optical system used in a compound eye imaging apparatus that performs final image output by dividing an imaging region of an imaging element, arranging lenses in each, and processing the obtained image is provided. In order to meet the demand for thinning, attention has been paid. In a compound-eye imaging device, since not so high optical performance is required for each lens, each lens can be formed small and thin, and a thin and small optical system as a whole can be obtained. Such an optical element in which a plurality of lenses are arranged in a matrix is called an array lens.

  By the way, it is preferable that the array lens is integrally formed by plastic injection molding using a mold because mass production is possible at low cost. However, when the array lens is molded by the mold, the mold is cooled from the mold temperature (100 ° C. to 130 ° C.) to the normal temperature (about 20 ° C.), so that plastic shrinkage is inevitable. Although the shrinkage rate varies depending on the type of plastic, it is generally about 0.3 to 0.8%. Therefore, before final commercialization, the lens position and surface accuracy of the array lens molded in the prototype are measured accurately, so that the lens position is optimized in a contracted state. It is necessary to correct the mold.

  Furthermore, since sufficient optical performance cannot be obtained with one lens, a plurality of lenses may be used. In such a case, if an array lens formed with a plurality of lenses is stacked, the plurality of lenses can be stacked in the optical axis direction at the same time, and there is an advantage that adjustment of individual lenses becomes unnecessary. However, if the shrinkage of the molded array lens is left unattended, problems such as decentering due to misalignment between individual lenses and improper distance between surfaces arise. Therefore, it is preferable to accurately measure the position of the lens even when the array lenses are stacked.

  On the other hand, Patent Document 1 discloses a technique for measuring the tilt, decentering, and surface accuracy of an optical axis of an array lens in which a plurality of lenses are arranged with a three-dimensional measuring machine (see FIG. 23 and the like).

JP 2008-2990 A JP 2012-78675 A

  By the way, according to Patent Document 1, the outer peripheral surface and the bottom surface of an array lens are pressed against a measurement reference sphere, and the coordinates are converted from the position of the measurement reference sphere to design the optical surface of the array lens in terms of eccentricity, inclination, and height. The deviation from the value is obtained. However, in this technique, since the outer shape of the array lens is used as a reference, it is necessary to press the array lens against the measurement reference sphere without any gap, for example, by a biasing force of a spring. However, since the array lens used in the compound eye optical system has a very thin shape, if the biasing force of the spring is applied in the direction perpendicular to the optical axis, the array lens is easily deformed, and an accurate measurement can be performed. There is no problem.

  In addition, when stacking array lenses used in a compound eye optical system, high decentration accuracy (for example, within 3 μm) and inter-surface distance accuracy are often required between opposing lenses. However, in the technique of Patent Document 1, since the measurement is performed based on the outer shape of the array lens, the measurement of the outer shape of the array lens and the individual lenses in the array lens can be performed. It is not possible to ensure the eccentricity accuracy and distance accuracy between individual lenses.

  On the other hand, Patent Document 2 discloses a technique for joining two array lenses using an alignment mark as a reference (see FIG. 4 and the like). However, since the positional relationship between the alignment mark and the optical surface is not defined in the technique of Patent Document 2, even though it can be said that the two array lenses can be joined to the defined position, the eccentricity accuracy and the inter-surface distance between the individual lenses. Accuracy cannot be ensured.

  The present invention has been made in response to such a problem of the prior art, and is capable of measuring the position of the optical surface of the lens unit with high accuracy and capable of positioning with respect to the counterpart with high accuracy, and a compound eye optical system. An object is to provide an imaging device, a measurement method, an evaluation method, and a manufacturing method.

  In order to achieve at least one of the above-described objects, an array lens reflecting one aspect of the present invention includes a plurality of lens units arranged with different optical axes and a flange unit that connects the plurality of lens units. And forming two first reference parts for measurement reference for measuring the position of the lens part at a predetermined interval on the flange part, and the first reference part comprises: When viewed in the optical axis direction, it is located outside the range connecting the outer circumferences of the outermost lens portions.

  According to this array lens, since two first reference portions for measuring reference of the array lens are formed at intervals in the flange portion, if the two first reference portions are measured using a three-dimensional measuring machine. Based on the result, the straight line connecting the two first reference portions is set in the X-axis direction, and the intermediate point between the two first reference portions is set as the origin as the reference position for measurement of the array lens. The reference position with respect to the lens can be clarified, and if the lens unit is measured using a three-dimensional measuring machine, the position of the lens unit with respect to the reference position can be obtained with high accuracy. If the position of the lens portion from the reference position can be determined for each array lens, the position of each lens portion in the array lens can be corrected with high accuracy. The “predetermined interval” means that the two first reference portions are apart from each other and have a predetermined positional relationship.

  Further, since the first reference portion is located outside the range connecting the outer periphery of the outermost lens portion when viewed in the optical axis direction, for example, referring to FIG. The range where the outer periphery of the lens unit is connected is indicated by a dotted line, but it becomes a substantially rectangular shape. By arranging the first reference unit outside this range, the measurement of the lens unit is not obstructed, and two The span of the first reference portion becomes long, and the reference position can be easily obtained with high accuracy. In addition, when the first reference portion is provided on the inner side of the above range, when the array lenses are stacked, it is common to provide a light shielding member between the array lenses, but the light shielding member is provided between the lens and the lens. Although the flange portion is provided so as to shield the light, the first reference portion interferes with the light shielding member.

  The compound-eye optical system is characterized in that the array lens is laminated.

  This imaging apparatus uses the compound eye optical system.

  In this measurement method, the first reference portion in the array lens is measured with a three-dimensional measuring machine, and the origin and the X-axis direction with respect to the array lens are determined based on the measurement result, and the position of the lens portion is evaluated. It is characterized by doing.

  By measuring the first reference portion of the array lens, the origin as the reference position and the X-axis direction can be obtained, which can be used as an evaluation reference.

  In this evaluation method, the first reference portion of the array lens is measured with a three-dimensional measuring machine, and based on the measurement result, the origin and the X-axis direction with respect to the array lens are determined, and the first reference portion is in contact with the counterpart member. A surface formed by the contact of the second reference portion is defined as an XY plane, a direction orthogonal to the XY plane and passing through the origin is defined as a Z-axis direction, and a direction intersecting the X-axis direction and the Z-axis direction is defined as Y. The position of the lens portion is evaluated by setting the axial direction.

  By measuring the first reference portion of the array lens, the origin as the reference position and the X-axis direction are obtained. Further, a surface formed by the contact of the second reference portion that is in contact with the mating member is defined as an XY plane, a direction orthogonal to the XY plane and passing through the origin is defined as a Z-axis direction, and the X-axis direction and the Z-axis By setting the direction intersecting the axial direction as the Y-axis direction, a three-dimensional coordinate system relating to the array lens can be determined, and the position of each lens unit with respect to the three-dimensional coordinate system can be determined uniquely with high accuracy.

  The method for manufacturing the array lens includes evaluating the array lens by the evaluation method, correcting the mold based on the evaluation result, and repeating the correction of the mold so that the array lens has a desired value. It is characterized by.

  According to this manufacturing method, the mold is corrected based on the evaluation result of the evaluation method, and the mold is corrected again by molding and the evaluation is repeated to obtain a desired value. Can be manufactured.

  ADVANTAGE OF THE INVENTION According to this invention, the position of the optical surface of each lens part in an array lens can be measured with a sufficient precision, and the array lens, compound eye optical system, imaging device, and measuring method which can be accurately positioned with respect to a counterpart An evaluation method and a manufacturing method can be provided.

It is a figure which shows typically the imaging device concerning this embodiment. It is sectional drawing of imaging unit LU. It is a flowchart which shows the manufacturing process of 1st array lens LA1. It is sectional drawing of the metal mold | die which shape | molds 1st array lens LA1. It is a figure which shows the image side surface of 1st array lens LA1 shape | molded using the metal mold | die of FIG. It is the figure which cut | disconnected the structure of FIG. 5 by the VI-VI line and looked at the arrow direction. It is sectional drawing of 1st reference | standard part LA1c. It is the figure which looked at alignment mark LA1d in the optical axis direction. It is a figure which shows the image side surface of 2nd array lens LA2. It is a figure which shows an example of the shift amount of the optical surface of the shape | molded array lens with respect to the optical surface of a design value. It is a figure which shows the state which laminates the array lenses LA1 and LA2. It is the figure (a) seen from the optical axis orthogonal direction which shows the modification of a 1st reference | standard part, and the figure (b) which shows the state observed with the camera in the state which laminated | stacked the array lens in the optical axis direction. It is the figure (a) seen from the optical axis orthogonal direction which shows the modification of a 1st reference | standard part and an alignment mark, and the figure (b) which shows the state observed with the camera in the state which laminated | stacked the array lens in the optical axis direction.

  First, an imaging apparatus having a compound eye optical system using the array lens according to the present embodiment will be described. A compound eye optical system is an optical system in which a plurality of lens systems are arranged in an array for one image sensor, and each lens system has a different field of view and a super-resolution type in which each lens system images the same field of view. Usually, it is divided into a field division type that performs imaging of the above. The compound eye optical system according to the present invention can be used for any type, but here super-resolution that outputs a single high-resolution composite image from a plurality of images of the same field obtained by a plurality of lens systems. The type will be described.

  FIG. 1 schematically shows an imaging apparatus according to the present embodiment. As illustrated in FIG. 1, the imaging device DU includes an imaging unit LU, an image processing unit 1 including a calculation unit 2, a memory 3, and the like. The imaging unit LU includes one imaging element SR and a compound-eye optical system LH that forms a plurality of images with substantially the same field of view on the imaging element SR. As the image sensor SR, for example, a solid-state image sensor such as a CCD image sensor or a CMOS image sensor having a plurality of pixels is used. Since the compound eye optical system LH is provided on the light receiving surface SS which is a photoelectric conversion unit of the image sensor SR so that an optical image of the subject is formed, the optical image formed by the compound eye optical system LH is captured. It is converted into an electrical signal by the element SR. The image composition unit 1a in the image processing unit 1 obtains one image data with higher resolution from a plurality of images based on electrical signals corresponding to a plurality of images sent from the image sensor SR. Execute the process.

  FIG. 2 is a cross-sectional view of the imaging unit LU. The compound-eye optical system LH includes a rectangular plate-shaped first array lens LA1 in which a plurality of (here, 16 pieces arranged in four rows and four columns) lens portions LA1a are integrally formed on the flange portion LA1b, and a plurality (here, four). A lens plate LA2a (16 pieces arranged in 4 rows and 4 columns) is laminated with a rectangular plate-like second array lens LA2 formed integrally with the flange portion LA2b. Details of the shape of the first array lens LA1 will be described later. The first array lens LA1 and the second array lens LA2 constitute a compound eye optical system.

  In FIG. 2, a first array lens LA1 and a second array lens LA2 that are integral with a thermoplastic resin are made of an integral body of translucent resin such as polycarbonate or acrylic resin, and a mold is used as will be described later. And obtained by injection molding. The optical axes OA of the lens part LA1a and the lens part LA2a coincide.

  In FIG. 2, a lens frame LF made of a light-shielding material such as black acrylic resin includes a rectangular frame-shaped side surface portion LF1 surrounding the compound eye optical system LH, and a top surface portion extending inward from the upper end of the side surface portion LF1. LF2. The top surface portion LF2 is formed with a plurality of openings LF2a (16 in this example arranged in 4 rows and 4 columns) as light transmitting portions centered on the optical axis.

  The lower end of the side surface portion LF1 of the lens frame LF is bonded to the upper surface of the substrate CT. An image sensor SR is formed on the substrate CT. It has a function of holding the cover glass CG so as to be disposed between the imaging element SR and the compound-eye optical system LH.

  In FIG. 2, a light shielding member SH made of a metal plate, a resin plate or the like is disposed between the first array lens LA1 and the second array lens LA2. The light shielding member SH is formed with a plurality of openings SHa (here, 16 pieces arranged in 4 rows and 4 columns) as light transmission parts with the optical axis as the center.

  Next, the manufacturing process of the compound eye optical system will be described. FIG. 3 is a flowchart showing manufacturing steps of the first array lens LA1. In FIG. 3, a mold for the first array lens LA1 is manufactured in step S101, and the first array lens LA1 is molded in step S102 using this mold. Further, the molded first array lens LA1 is measured in step S103, and the mold is corrected in step S104 based on the result (including a case of newly manufacturing). Thereafter, the first array lens LA1 is molded again in step S105 using the corrected mold, and measurement is performed again in step 106. In subsequent step S107, the measured value of the molded first array lens LA1 is compared with the design value. If the measured value is not within the allowable range (No), the process returns to step S104 again to correct the mold. On the other hand, if the molded first array lens LA1 is within the allowable range with respect to the design value (Yes), in step S108, the first array lens LA1, the separately molded light shielding member SH and the second array lens LA2 are laminated. Then, a compound eye optical system is manufactured. Hereinafter, the contents of each main process will be described more specifically.

  FIG. 4 is a cross-sectional view of a mold for molding the first array lens LA1. Plastic materials that can be used for array lenses are broadly classified into thermoplastic resins and energy curable resins, but they are generally manufactured from thermoplastic resins that can be manufactured by injection molding with excellent mass productivity and low cost. is there.

  In FIG. 4, an upper mold MD1 and a lower mold MD2 are provided. The upper mold MD has a transfer surface MD1a for transferring one optical surface of the lens portion LA1a of the first array lens LA1. The lower mold MD2 includes a transfer surface MD2a that transfers the other optical surface of the lens portion LA1a of the first array lens LA1, a transfer surface MD2b that transfers the first reference portion, and a transfer surface MD2c that forms the second reference portion. And a transfer surface MD2d for transferring the alignment mark. The transfer surfaces MD2a to 2d are processed using the same tool when being cut from the material of the lower mold MD2. Therefore, since a tool is not exchanged, a manufacturing error hardly occurs. The transfer surfaces of the upper mold MD1 and the lower mold MD2 are required to have a processing accuracy of 10 nm level in order to form an optical surface. Since general-purpose machine tools cannot achieve the level of machining accuracy, ultra-precision machine tools are often used for machining.

  After being molded by the mold, the array lens is cooled from the mold temperature (100 ° C. to 130 ° C.) to room temperature (about 20 ° C.), and thus shrinkage occurs. Although the shrinkage rate varies depending on the type of resin, it is generally about 0.3 to 0.8%. Therefore, it is necessary to make a mold for injection molding larger than the array lens design shape by a contraction rate.

  FIG. 5 is a diagram showing an image side surface of the first array lens LA1 molded using the mold of FIG. 6 is a view of the configuration of FIG. 5 taken along the line VI-VI and viewed in the direction of the arrow. In FIG. 5, the first array lens LA1 is opposed to the lens portion LA1a arranged in 4 rows and 4 columns between the second row and the third row and outside the first and fourth rows. A pair of first reference portions LA1c are formed at an equal distance from the side, and a pair of alignment marks LA1d are formed on the outside thereof. Since the first reference portion LA1c and the alignment mark LA1d are close to each other, the influence of contraction is equally exerted. Two second reference portions LA1e are formed outside the first row and the fourth column outside the fourth row of the lens portion LA1a, and outside the first row of the lens portion LA1a. One second reference portion LA1e is formed between the second row and the third row.

  Here, the first reference portion LA1c is a part of a spherical surface and has a maximum diameter of 0.2 mm or more. As shown in FIG. 7, the surface of the flange portion LA1b and the contact surface of the portion where the first reference portion LA1c contacts The angle θ formed with CP is 45 degrees or more. On the other hand, the second reference portion LA1e has a simple cylindrical shape. As shown in FIG. 8, the alignment mark LA1d has two circular portions formed on the end face of the cylinder. In the case of the alignment mark, the main purpose is to make it easy to recognize with an image, so two circular portions are provided in the cylinder.

  Next, measurement of the first reference portion LA1c and the second reference portion LA1e will be described. In FIG. 5, by using a three-dimensional measuring machine (not shown) to measure the two first reference portions LA1c of the first array lens LA1, the apex position P1 can be obtained. Since the first reference portion LA1c needs to be measured accurately in order to define the origin and the coordinate axis in the X-axis direction, it is desirable that the first reference portion LA1c has a shape that can be easily measured by a three-dimensional measuring machine. In the present embodiment, it is a hemisphere having a diameter of 0.2 mm or more, and since the angle formed between the contact surface of the portion in contact with the surface of the flange portion and the hemispheric surface is close to 90 °, the shape can be easily specified. Precise measurement is possible. Here, the midpoint of the line segment L1 connecting the two positions P1 is the origin O, and the direction of the line segment L1 is the X-axis direction.

  Next, by measuring the three second reference portions LA1e using the same three-dimensional measuring machine, as shown in FIG. 6, the XY plane PL formed at the three height positions can be found. Further, the difference Δ between the origin O and the XY plane can be known. A direction orthogonal to the XY plane PL and passing through the origin O is defined as a Z-axis direction. Further, the Z-axis direction and the direction orthogonal to the X-axis direction on the XY plane are defined as the Y-axis direction. Thereby, the three-dimensional coordinate system regarding the first array lens LA1 is determined. Then, using the same three-dimensional measuring machine, the apex (optical axis position) and height of the optical surface of each lens unit LA1a are measured, and converted to the obtained coordinates on the three-dimensional coordinate axis. Furthermore, the coordinate value after the coordinate conversion of the optical surface is fitted by the least square method so that the difference from the optical surface design value is minimized. Thereby, a difference from the design value (difference in the X-axis direction, Y-axis direction, and axis Z direction of the optical center, inclination in the X-axis direction and Y-axis direction, difference in optical surface shape, etc.) is obtained. As a result, the molded array lens can be evaluated. By appropriately evaluating the array lens, the mold can be corrected (step S104 in FIG. 3). More specifically, the height and position of the transfer surfaces MD1a and MD2a of the molds MD1 and MD2 shown in FIG. 4 are changed based on the amount of deviation between the axial position of the lens unit after molding and the design value. Rework. The actually molded array lens is often warped as a whole, and in such a case, it is desirable to individually correct the transfer surface of the mold. If rework is not possible, the mold is re-formed. For the evaluation in the Z-axis direction, correction is made so that the lens unit height is aligned or the inclination of the XY plane is corrected so that the Z-direction position of the lens unit is the same position in other lens units. The height of the second reference portion can also be corrected, and in the X and Y directions, each position of the lens portion can be corrected or the position of the first reference portion can be changed.

  In the second array lens LA2, similar molding is performed using a mold (not shown). FIG. 9 is a diagram illustrating the object side surface of the molded second array lens LA2. A first reference portion LA2c is formed opposite to the first reference portion LA1c of the first array lens LA1, and a second reference portion LA2e is formed opposite to the second reference portion LA1c of the first array lens LA1. An alignment mark LA2d is formed to face the alignment mark LA1d of the array lens LA1. However, when the alignment mark LA2d is aligned with the alignment mark LA1d, the two circles are shifted by 90 degrees as shown by the dotted line in FIG. On the other hand, the first reference portion and the second reference portion have the same shape.

  For the second array lens LA2, the same measurement is performed after molding, the vertex and height of each optical surface are obtained on the three-dimensional coordinate axis related to the second array lens LA2, and fitting is similarly performed by the least square method.

  In order to reduce the eccentricity of all the lens portions LA1a and LA2a between the two array lenses LA1 and LA2 to 2 μm or less, for example, the amount of deviation from the design position of the optical surface in one array lens should be halved to 1 μm or less. There must be. However, in an actually molded array lens, the optical surface may be displaced from the design position by about 5 μm due to shrinkage. An example of the deviation between the measured optical surface position of the lens unit and the designed position is shown in FIG. In this case, in the figure, the lower side (side closer to the gate) has a larger pitch, and the upper side (side far from the gate) has a smaller pitch. This is because the pitch is increased because the pressure closer to the gate is more likely to be applied by the injection molding machine.

  Regarding the height of the optical surface (Z-direction misalignment), the inclination of the optical surface, and the optical surface shape, it is difficult to satisfy the required accuracy required for the lens from the first molding as with the pitch. For this reason, it is necessary to perform mold correction processing using the measured data so as to cancel an error caused by molding. According to the present embodiment, since the three-dimensional coordinate axis is determined with high accuracy for each array lens, the optical surface can be measured with high accuracy, and based on the measurement result, the gold accuracy is satisfied so as to satisfy the required lens accuracy. Mold correction processing can be performed with high accuracy.

  By forming the first array lens LA1 and the second array lens LA2 again using the corrected mold, the shift amounts of the lens portions LA1a and LA2a are all within 1 μm. Therefore, as shown in FIG. 11, when the second reference portion LA1e of the first array lens LA1 and the second reference portion LA2e of the second array lens LA2 are brought into contact with each other with the light shielding member SH interposed therebetween. Both share the same XY plane PL. At this time, the camera CA arranged in the optical axis direction can align the relative positions by imaging the alignment marks LA1d and LA2d (the four circles of the alignment mark are arranged on the object). Using the first reference portions LA1c and LA2c and the second reference portions LA1e and LA2e as a reference, the XY positions of the optical surfaces of the lens portions LA1a and LA2a and the optical surface height with respect to the Z-direction reference surface are the above-described measurements. Therefore, the error between the eccentricity of the optical surfaces and the air gap can be suppressed with high accuracy. Thereafter, by applying an ultraviolet curable adhesive or the like between the first array lens LA1 and the second array lens LA2, the two are bonded and incorporated into the lens frame LF.

  The array lens can be used for a compound eye optical system of an imaging apparatus including a compound eye optical system such as a super-resolution type or a field division type. In the above-described embodiment, as a result of obtaining the visibility of the alignment mark, the first reference portion and the alignment mark are separated from each other, but may be integrated. For example, as shown in FIG. 12A, the first array lens LA1 is provided with a pair of small hemispherical first reference portions LA1c, and the second array lens LA2 is provided with a larger hemispherical first reference portion LA2c. A pair can be provided. By measuring the first reference portions LA1c and LA2c, the origins and X-axis directions of the respective array lenses LA1 and LA2 can be obtained. On the other hand, when the array lenses LA1 and LA2 are stacked and observed with the camera CA (FIG. 11) from the optical axis direction, the first reference portion LA2c and the first reference portion LA1c are arranged coaxially in the positioned state. Therefore, it can be seen that this is an appropriate position.

  In the separate example shown in FIG. 13A, an alignment mark LA1d that is a small-diameter annular portion is formed around the hemispherical first reference portion LA1c in the first array lens LA1, and the second array lens LA2 is formed. The alignment mark LA2d, which is a large-diameter annular portion, is formed around the hemispherical second reference portion LA2c. When the array lenses LA1 and LA2 are stacked and observed with the camera CA (FIG. 11) from the optical axis direction, the alignment mark LA2d and the alignment mark LA1d are arranged coaxially in the positioned state. It turns out that it is a position.

  Hereinafter, preferred aspects of the array lens of the present embodiment will be described together.

  In the array lens, it is preferable that the first reference portion has a rotationally symmetric shape. If the first reference portion has a rotationally symmetric shape, it is easy to measure the shape of the first reference portion when measuring with a three-dimensional measuring machine, so that the center position of the first reference portion can be obtained with high accuracy. As a result, the position of the lens portion can be easily obtained with high accuracy. The three-dimensional measuring machine may be a contact type using a probe or a non-contact type such as an interferometer.

  The first reference portion preferably has a maximum width of 0.2 mm or more when viewed in the optical axis direction. By having such a width, the first reference portion can be easily measured by a three-dimensional measuring instrument, and the coordinates of the first reference portion can be measured with high accuracy.

  Moreover, it is preferable that the said 1st reference | standard part is 45 degrees or more of the maximum angle which the contact surface of the site | part which contact | connects the surface of the said flange part, and the said surface. Accordingly, the first reference portion can be easily measured by a three-dimensional measuring instrument, and the coordinates of the first reference portion can be measured with high accuracy. If the maximum angle is 45 degrees or more, the difference in height between the convex portion or concave portion of the shape of the first reference portion and the flat portion around it tends to be clear, so the shape of the first reference portion is specified. It becomes easy.

  Moreover, it is preferable that the said array lens is resin integral molding. Thereby, an array lens can be manufactured at low cost. On the other hand, in the case of an integrally molded resin product, the lens part is displaced due to shrinkage after molding. However, according to the present invention, the shape and position of the lens part can be accurately measured. It can be done with high accuracy.

  The mold for transferring and forming the first reference portion is preferably the same member as the mold for transferring and forming the optical surface of the lens portion. As a result, the positional accuracy between the first reference portion and the lens portion is increased, so that the die correction processing can be performed with high accuracy.

  In addition to the first reference part, the flange part has three second reference parts so as to form a triangle, and the second reference part corresponds to a mating member on which the array lenses are laminated. It is preferable to contact.

  When the array lenses are stacked, the positional relationship with the mating member becomes a problem. According to the present embodiment, apart from the first reference portion, the flange portion has three second reference portions so as to form a triangle. In addition, a plane in a direction substantially orthogonal to the optical axis direction is specified, and when the layers are stacked, the positional relationship with the counterpart member can be accurately ensured by bringing the second reference portion into contact with the counterpart member. The “partner member” includes a light shielding member and a solid-state imaging element in addition to an optical element such as an array lens.

  In addition, the counterpart member is another array lens having the second reference portion, and it is preferable that the second reference portions are brought into contact with each other. When array lenses are stacked, a reference plane (for example, an XY plane) is determined at the three contact points by bringing the second reference portions into contact with each other. On the other hand, in each array lens, since the reference position is determined by the measurement of the first reference portion, the accuracy of the lens portion of each array lens with respect to the three-dimensional coordinate system determined from the reference position and the reference plane is determined. Since measurement can be performed well, it is possible to accurately stack the two array lenses formed by the corrected molds after correcting the molds with high accuracy.

  Moreover, it is preferable that both of the second reference portions that are in contact with each other have a flat surface. Thereby, the second reference portions can be brought into contact with each other simultaneously. However, it is preferable that the area of the second reference portion is small so that three points can be secured.

  In addition, it is preferable that one of the second reference portions in contact with each other has a flat surface and the other has a spherical surface. Thereby, the second reference portions can be brought into contact with each other simultaneously.

  The mold for transferring and forming the second reference portion is preferably the same member as the mold for transferring and forming the optical surface of the lens portion. As a result, the positional accuracy between the second reference portion and the lens portion is increased.

  In addition, it is preferable to form alignment marks in the vicinity of the first reference portion of the array lenses to be stacked.

  When the array lenses are stacked, the array lenses are positioned and stacked by visually recognizing the alignment mark. For example, the first reference portion may be used as an alignment mark, but depending on the shape of the first reference portion, it may not be suitable for imaging with a camera for visual recognition. In such a case, the array lens can be stacked with high accuracy by separately providing an alignment mark that is easily visible.

  The mold for transferring and forming the alignment mark is preferably the same member as the mold for transferring and forming the first reference portion. Thereby, the positional accuracy between the alignment mark and the first reference portion is increased.

  The present invention is not limited to the embodiments and modifications described in the present specification, and includes other embodiments and modifications based on the embodiments and technical ideas described in the present specification. It will be apparent to those skilled in the art.

DESCRIPTION OF SYMBOLS 1 Image processing part 1a Image composition part 2, Computation part 3 Memory CA Camera CG Cover glass CP Contact surface CT board | substrate DU Image pick-up device LA1 1st array lens LA1a Lens part LA1b Flange part LA1c 1st reference | standard part LA1d Alignment mark LA1e 2nd reference | standard Part LA2 Second array lens LA2a Lens part LA2b Flange part LA2c First reference part LA2d Alignment mark LA2e Second reference part LF Mirror frame LF1 Side face part LF2 Top face part LF2a Opening LH Compound eye optical system LU Imaging unit MD1 Upper mold MD1a Transfer surface MD2 Lower mold MD2a-2d Transfer surface O Origin OA Optical axis PL Flat surface SH Light shielding member Sha Opening SR Image sensor SS Light receiving surface

Claims (18)

In an array lens having a plurality of lens portions arranged with different optical axes, and a flange portion connecting the plurality of lens portions,
Forming two first reference parts for measuring reference for measuring the position of the lens part at a predetermined interval on the flange part;
The array lens according to claim 1, wherein the first reference portion is located outside a range connecting the outer circumferences of the lens portions located on the outermost side when viewed in the optical axis direction.   The array lens according to claim 1, wherein the first reference portion has a rotationally symmetric shape.   The array lens according to claim 1, wherein the first reference portion has a maximum width of 0.2 mm or more when viewed in the optical axis direction.   4. The array lens according to claim 1, wherein the first reference portion has a maximum angle of 45 ° or more between a contact surface of a portion in contact with the surface of the flange portion and the surface.   The array lens according to claim 1, wherein the array lens is an integrally molded product of resin.   The array lens according to claim 1, wherein the mold for transferring and forming the first reference portion is the same member as the mold for transferring and forming the optical surface of the lens portion.   Aside from the first reference part, the flange part has three second reference parts so as to form a triangle, and the second reference part comes into contact with a mating member on which the array lenses are stacked. Item 7. The array lens according to any one of Items 1 to 6.   The array lens according to claim 7, wherein the counterpart member is another array lens having the second reference portion, and the second reference portions are brought into contact with each other.   The array lens according to claim 8, wherein both of the second reference portions in contact with each other have a flat surface.   The array lens according to claim 9, wherein one of the second reference portions in contact with each other has a flat surface and the other has a spherical surface.   The array lens according to any one of claims 7 to 10, wherein a mold for transferring and forming the second reference portion is the same member as a mold for transferring and forming the optical surface of the lens portion.   The array lens according to claim 1, wherein an alignment mark is formed in the vicinity of the first reference portion of the array lens to be laminated.   The array lens according to claim 12, wherein a mold for transferring and forming the alignment mark is the same member as a mold for transferring and forming the first reference portion.   A compound eye optical system formed by laminating the array lens according to claim 1.   An imaging device using the compound eye optical system according to claim 14.   The first reference portion in the array lens according to any one of claims 1 to 13 is measured by a three-dimensional measuring machine, and based on the measurement result, an origin and an X-axis direction with respect to the array lens are determined, and the lens Measuring method to measure the shape of the part.   The first reference portion in the array lens according to any one of claims 7 to 11 is measured by a three-dimensional measuring machine, and based on the measurement result, an origin and an X-axis direction with respect to the array lens are determined, and the counterpart A surface formed by the contact of the second reference portion that is in contact with a member is defined as an XY plane, a direction orthogonal to the XY plane and passing through the origin is defined as a Z-axis direction, and the X-axis direction and the Z-axis direction are defined as An evaluation method for evaluating the position of the lens unit by setting the direction intersecting with the Y-axis direction.   The array lens according to any one of claims 7 to 11 is evaluated by the evaluation method according to claim 17, the mold is corrected based on the evaluation result, and the array lens has a desired value. A method of manufacturing an array lens in which mold correction is repeated

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