JP2009069694A - Image pickup apparatus and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup apparatus in which an image pickup lens system can be attached to an image pickup element with excellent positional precision even in the case where a part of the effective pixel area of the image pickup element is covered by an aperture. <P>SOLUTION: The image pickup apparatus 1 includes: a lens holder 21 that has the aperture 26 for holding an image pickup lens system 31; a sensor chip 11 that converts light passed through the image pickup lens system 31 to an electric signal; and a marker 18a which positions the lens holder 21. The lens holder 21 is designed so as to cover a part of the effective pixel area 12 of the sensor chip 11 through the aperture 26. In addition, at least a part of the marker 18a is disposed in the position where it can be viewed through the aperture 26 of the lens holder 21 and outside the effective pixel area 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging apparatus that captures an image of a subject using an imaging element, such as a digital camera and a digital video camera, and a manufacturing method thereof.

  An imaging apparatus such as a digital camera or a digital video camera converts light from a subject into an electrical signal, and forms image data of the subject based on the electrical signal. More specifically, the imaging apparatus normally includes an imaging unit (hereinafter referred to as an imaging unit) that recognizes light from a subject imaged by the imaging lens system, and the light recognized by the imaging unit is In the solid-state imaging device provided in the imaging unit, it is converted into an electrical signal and output. The output electrical signal is converted into image data in the processing unit of the imaging apparatus. In general, the imaging unit has a configuration in which a solid-state imaging device is provided in a unit case including a flat plate-like protective glass having a uniform thickness on the light incident side. The protective glass is formed of a material that does not prevent light from entering, and is a member for protecting solid-state imaging from adverse effects such as adhesion of foreign matter to the solid-state imaging device or damage due to a physical cause.

  In an imaging apparatus such as a general digital camera, in order to form a good image quality in a solid-state imaging device, the position adjustment (XY adjustment) and imaging between the effective pixel region center of the solid-state imaging device and the optical axis of the imaging lens system are performed. Focus adjustment is performed to adjust the focal point of the lens system with respect to the solid-state imaging device.

  Patent Document 1 discloses a method of acquiring position information by reading a marker provided in an imaging unit with an image processing camera or the like, and feeding back to the posture adjustment of the imaging lens system. The imaging unit disclosed in Patent Document 1 will be described with reference to FIGS. 16 (a) and 16 (b). As shown in FIGS. 16A and 16B, in the imaging unit described in Patent Document 1, a CCD chip 144 and a color separation filter 142 are arranged on a CCD package 141. Then, on the optical filter 142 positioned therebetween, markers 143A to 143D are provided at the outer peripheral corners of the imaging surface. Thus, XY adjustment and focus adjustment can be performed based on the position information detected by the image processing camera.

  However, in an imaging device that is miniaturized and thinned mounted on a portable device such as a cellular phone, the XY adjustment described above is hardly performed although it depends on a margin with respect to the positional deviation of the optical lens system that is configured. Instead, only focus adjustment is performed. In this way, in an imaging device that has not performed XY adjustment, light that has passed through the imaging lens system cannot be combined with the effective area of the solid-state imaging device with high positional accuracy, and thus an image with good peripheral light quantity can be obtained. I can't.

  In recent years, an imaging apparatus in which the number of lenses of the imaging lens system is reduced has been developed in order to reduce the size and thickness of the imaging apparatus. However, the smaller the number of imaging lens systems, the more difficult it is to correct incident light. Correction of incident light will be described below with reference to FIG. Note that an imaginary line O in FIG. 17 represents the central axis of the light transmitted through the imaging lens system. That is, the imaginary line O can be rephrased as the optical axis O.

  As shown in FIG. 17, the light transmitted through the imaging lens system reaches the solid-state imaging device 102 through the protective glass 101. Of the light incident on the solid-state image sensor 102, the light incident on a position away from the optical axis O has an angle that spreads outward from the optical axis O. That is, the light having an angle away from the optical axis O is incident toward the outside of the solid-state imaging element 102. Thus, if the incident light has an angle that leaves the optical axis O away from the outside, the efficiency of incidence on the solid-state imaging device 102 is reduced, making it difficult to efficiently convert the light into an electrical signal. become.

  Furthermore, when an imaging apparatus including a solid-state imaging unit having a protective glass as described above is reduced in size and thickness, light transmitted through the imaging lens inevitably widens. As a result, the difference in incidence efficiency between the central portion and the peripheral portion of the solid-state imaging device is further increased, and there arises a problem that the peripheral portion of the formed image becomes extremely dark.

  In addition, a CCD (Charge Coupled Device) and a C-MOS device that are generally used as a solid-state imaging device have a relatively wide wavelength (not only in the visible light region but also in the near infrared region (750 to 2500 nm). ) Light can be converted into an electrical signal. However, when used as a normal camera, the solid-state imaging device converts near infrared rays into an electrical signal, thereby causing degradation in image quality such as a decrease in resolution and image unevenness. For this reason, in a normal camera, colored glass or the like is inserted as an infrared cut filter to cut near infrared rays in incident light. In recent years, in order to reduce the cost and size of an imaging apparatus, a method of cutting (reflecting) near infrared light by forming an inexpensive dielectric multilayer film on a protective glass as an infrared cut filter has been widely employed.

  The dielectric multilayer film is inexpensive, but has an angle dependency in which the range of the wavelength of the reflected light changes depending on the angle of the incident light. That is, as the incident angle of light increases, the wavelength range of light that can be reflected by the dielectric multilayer film shifts to a shorter wavelength. Therefore, the dielectric multilayer film has a problem that, as the incident angle of light increases, it becomes easier to reflect light having a shorter wavelength than the near infrared wavelength. In other words, the larger the incident angle of light, the lower the function of the dielectric multilayer film as an infrared cut filter.

  In order to solve the above problems, for example, solid-state imaging units described in Patent Documents 2 and 3 are disclosed. As shown in FIG. 18, the imaging element unit (imaging unit) described in Patent Document 1 includes a lens portion 115b that is formed integrally with a glass plate 115a and does not have an imaging function. . As a result, the image sensor unit described in Patent Document 1 refracts light incident on the periphery of the sensor chip 114 so as to be substantially parallel to the optical axis O.

  In addition, as shown in FIG. 19, the solid-state imaging device (imaging unit) described in Patent Document 2 includes a dielectric multilayer film including a dielectric multilayer film 133 and a resin focusing lens 132 on a flat surface of a light-transmitting substrate 134. A filter 134 is provided. As a result, the solid-state imaging device described in Patent Document 2 allows light incident on the vicinity of the outer periphery of the sensor chip 135 via the path indicated by the arrow L2 to be more parallel to the arrow L0 on the incident surface of the resin focusing lens 132. It is refracted to become.

  As described above, in an imaging device in which an optical element such as the lens portion 115b or the resin focusing lens 132 is formed in the vicinity of the solid-state imaging device, the incident efficiency in the vicinity and the outer periphery of the sensor chip without increasing the number of imaging lens systems. Therefore, the number of lenses of the imaging lens system can be reduced, and the imaging device can be reduced in size and thickness.

However, in an imaging apparatus in which an optical element is provided in the vicinity of a solid-state imaging element, adjustment (XY adjustment) on the XY plane of the position of the imaging lens system and the newly provided optical element is required. However, in an imaging apparatus that has been reduced in size and thickness, an adjustment mechanism cannot be built in the imaging apparatus due to space limitations. Therefore, for example, after the orientation of the imaging lens system is directly adjusted with respect to the held imaging unit using an XYZ stage or the like, the solid-state imaging unit and the imaging lens system are bonded.
JP 60-207107 (released October 18, 1985) JP-A-11-97659 (published on April 9, 1999) JP 2005-234038 (published September 2, 2005)

  For example, in order to accurately position the imaging lens system using a positioning means such as a marker, it is most preferable to visually recognize the positioning means through the imaging lens system, but it is necessary to visually recognize the positioning means through an intense condenser lens. Is very difficult. Therefore, generally, a method is adopted in which a lens holder for mounting an imaging lens system is positioned with high accuracy using positioning means and then attached to the lens holder on which the imaging lens system is mounted.

  2. Description of the Related Art In recent years, an imaging device has been required to have high functionality by mounting an autofocus mechanism (hereinafter also referred to as an AF mechanism) and the like in addition to downsizing and thinning. For example, when an AF mechanism is mounted in a downsized and thin imaging device, an actuator used for the AF mechanism is generally arranged around the lens holder. Therefore, in order to secure a space for mounting the AF mechanism, it is necessary to reduce the lens diameter used in the imaging lens system, and accordingly, the size of the opening of the lens holder that holds the imaging lens diameter is large. It also gets smaller. Thus, as in the technique described in Patent Document 1, when a positioning unit is provided at a corner portion of a solid-state imaging device (hereinafter, also simply referred to as an imaging device), a high-performance imaging device equipped with an AF mechanism or the like The positioning means cannot be visually recognized through the lens holder using the image processing camera, and XY adjustment of the positions of the imaging lens system and the imaging unit becomes very difficult.

  As a result, a positional deviation occurs between the center of the effective pixel region of the image sensor provided in the imaging unit and the center of the lens holder diameter (that is, the optical axis of the imaging lens system). Therefore, the light incident on the position away from the optical axis of the imaging lens system forms an image outside the effective pixel region, and thus there is a problem that the amount of light in the peripheral portion of the imaging element is insufficient.

  Moreover, when the positioning means is provided at a portion other than the corner portion, the light that has passed through the marker reaches the aluminum electrode directly. An aluminum electrode is also provided for light shielding, but there are many defects because it is manufactured by vapor deposition. Accordingly, there is a problem that the light that has reached leaks from the defect and becomes smeared when entering the image sensor. In other words, the positioning means is preferably provided at the corner of the image sensor in order to avoid the appearance of image noise due to smear in the center.

  Furthermore, in the case of an image pickup apparatus in which an optical element for correcting the angle of incident light is provided in the vicinity of the image pickup element, the amount of light at the periphery of the image pickup element is not sufficient, but also due to aberrations in the optical system, etc. MTF (Modulation Transfer Function) decreases, and the performance as an imaging device cannot be exhibited.

  The present invention has been made in view of the above problems, and its main purpose is to capture an image even when a part of the effective pixel region of the image sensor is covered by the opening of the lens holder. An object of the present invention is to provide an imaging apparatus capable of attaching an imaging lens system to an element with high positional accuracy.

  Note that when an optical element is provided in the vicinity of the image pickup element, the positioning means cannot be visually recognized, so that the positions of the optical element and the image pickup lens system cannot be XY-adjusted. Furthermore, since the positioning means is not formed with high accuracy with respect to the optical element, it is difficult to accurately adjust the position of the optical element and the imaging lens system.

In order to solve the above problems, an imaging apparatus according to the present invention provides
An image pickup having a lens holder having an opening for holding an image pickup lens system, an image pickup element for converting light passing through the image pickup lens system into an electric signal, and positioning means for determining a position of the lens holder with respect to the image pickup element In the device
The opening of the lens holder is designed so that the lens holder covers a part of the effective pixel area of the imaging device,
The positioning means is characterized in that at least a part of the positioning means can be visually recognized through the opening of the lens holder and is provided outside the effective pixel region.

  According to said structure, when positioning a lens holder using a positioning means, a positioning means can be visually recognized through the opening part of a lens holder. Thereby, the position of the lens holder with respect to the image sensor can be determined with high accuracy. The position of the imaging lens system is determined by attaching it to the opening of the lens holder. In other words, accurately determining the position of the lens holder with respect to the image sensor is synonymous with accurately determining the position of the image lens system with respect to the image sensor. As a result, even when the lens holder covers a part of the effective pixel area of the image sensor, the imaging lens system is attached so that the optical axis of the imaging lens system substantially matches the center of the effective image area. Can do.

  Therefore, even if the light is incident at a position away from the optical axis of the imaging lens system, it can be imaged with high positional accuracy within the effective pixel region of the imaging element, so that a good image can be formed on the imaging element. There is an effect that can.

The imaging apparatus according to the present invention further includes an optical element that is provided between the imaging element and the imaging lens system, and that corrects light that has passed through the imaging lens system.
The positioning means is preferably provided in the optical element.

  According to the above configuration, since the position of the imaging lens system with respect to the optical element can be determined without considering the optical characteristics of the optical element, the position of the imaging lens with respect to the optical element can be accurately determined. In addition, since the optical element is accurately positioned with respect to the imaging element, the position of the imaging lens system with respect to the imaging element can be determined with high accuracy by accurately determining the position of the imaging lens with respect to the optical element. .

  That is, it is possible to accurately determine the position of the imaging lens system with respect to the optical element and the imaging element in the imaging device including the optical element. As a result, even in an imaging apparatus including an optical element, there is an effect that a good image can be formed.

  The positioning means is preferably provided in an effective area of the optical element.

  The positioning means is preferably provided within a projection area when the lens holder is projected onto the image sensor.

  In the imaging device according to the present invention, it is preferable that the positioning means is a protrusion or a groove.

  When the positioning means is a protrusion, that is, when it has a convex shape, the mold forming the positioning means has a concave shape. Since the concave mold can be formed by digging the mold raw material, the time required for the mold manufacture can be shortened, and the mold manufacturing cost can be suppressed. . Further, when the positioning means is a groove, that is, when it is concave, the reflectance of the positioning means with respect to other than the positioning means can be reduced. Thereby, there is an effect that the visibility by a camera or the like can be improved.

  In the imaging apparatus according to the present invention, it is preferable that the positioning means has a hemispherical shape, a cone shape, or a frustum shape.

  According to said structure, there exists an effect which can ensure releasability with the type | mold which shape | molds the positioning means, and when the positioning means is provided in the optical element, the scattering of light in an optical element There is an effect that can be sufficiently reduced.

  In the imaging apparatus according to the present invention, it is preferable that a plurality of the positioning means are provided.

  According to said structure, there exists an effect which can position a lens holder more accurately with respect to an image pick-up element.

  In the imaging apparatus according to the present invention, it is preferable that the positioning means is provided at a position that equally divides the circumference of a circle centered on the optical axis of the imaging lens system.

  According to said structure, in the calculation by image processing, there exists an effect which can recognize the center of an effective pixel area | region with a simple algorithm. Further, for example, when the positioning means is provided in the optical element, the internal strain to the optical element by the positioning means is evenly distributed as axial symmetry, so that the deformation of the optical element can be suppressed evenly and reliably. There is an effect that can.

  In the imaging device according to the present invention, in the optical element, a difference between a transmittance in a region where the positioning unit is formed and a transmittance in a region where the positioning unit is not formed is 4% or more. Preferably there is.

  According to said structure, when the positioning means is visually recognized through the lens holder, the positioning means can be easily recognized.

  In the imaging device according to the present invention, it is preferable that an antireflection layer is provided in a region of the optical element excluding the region where the positioning means is formed.

  According to the above configuration, there is an effect that a difference in transmittance can be easily generated between the positioning unit and the region excluding the region where the positioning unit is formed without impairing the characteristics of the optical element. Play.

In order to solve the above problems, the manufacturing method according to the present invention provides
An image pickup having a lens holder having an opening for holding an image pickup lens system, an image pickup element for converting light passing through the image pickup lens system into an electric signal, and positioning means for determining a position of the lens holder with respect to the image pickup element In the device
A lens holder forming step of designing the opening of the lens holder so that the lens holder covers a part of the effective pixel region of the imaging device;
And a positioning means forming step of forming at least a part of the positioning means at a position that can be visually recognized through the opening of the lens holder.

  According to said structure, there exists an effect similar to the imaging device which concerns on this invention.

In the manufacturing method according to the present invention, the formation step further includes:
A filling step of filling the transfer mold with a resin having fluidity;
And a curing step of curing the resin filled in the transfer mold.

  According to said structure, since a positioning means can be resin-molded, there exists an effect which can shape | mold the positioning means of a desired shape easily.

  In the manufacturing method according to the present invention, further, in the positioning means forming step, the positioning element is provided between the imaging element and the imaging lens system, and the optical element that corrects light passing through the imaging lens system is provided. It is preferable to form.

  In the imaging apparatus provided with the optical element, there is an effect that the imaging lens system, the optical element, and the imaging element can be accurately positioned.

  In the manufacturing method according to the present invention, it is preferable that the optical element and the positioning means are simultaneously molded in the positioning means forming step.

  According to the above configuration, the positioning means and the optical element can be molded easily and more accurately in terms of mold accuracy than after being bonded to the optical element. As a result, there is an effect that it is possible to form a positioning means with high positional accuracy with respect to the optical axis of the optical element.

  In the manufacturing method according to the present invention, the transfer mold preferably includes an optical element transfer portion for forming the optical element and a positioning means transfer portion for forming the positioning means.

  According to said structure, an optical element and a positioning means can be resin-molded simultaneously. As a result, there is an effect that an optical element including positioning means provided with high positional accuracy with respect to the optical axis of the optical element can be manufactured with high productivity and at low cost.

  Further, since not only the positioning means but also the optical element can be molded by resin molding, there is also an effect that an optical element having a desired shape can be easily molded.

  In the manufacturing method according to the present invention, it is preferable that the transfer mold is made of a material that transmits light.

  According to the above configuration, since the resin filled in the transfer mold and the transfer mold are transparent, the effective pixel region can be visually recognized through the transfer mold filled with the resin. As a result, there is an effect that the center of the effective pixel region and the optical axis of the optical element can be made to substantially coincide with each other.

  In the manufacturing method according to the present invention, it is preferable that the positioning means transfer portion is formed by patterning a surface of the optical element transfer portion.

  According to said structure, a positioning means transcription | transfer part can be formed easily and accurately. As a result, there is an effect that a transfer mold that needs to be formed with high accuracy can be manufactured more easily and inexpensively.

  In the production method according to the present invention, the resin is preferably an energy curable resin that is cured by at least one of light energy and thermal energy.

  According to said structure, there exists an effect which can shape | mold the optical element and positioning means which have a desired shape still more easily.

  In the production method according to the present invention, the resin is preferably a thermoplastic resin.

  According to said structure, there exists an effect which can manufacture an optical element and a positioning means in large quantities and cheaply.

The manufacturing method according to the present invention further includes a fixing step of fixing the optical element including the positioning unit to an imaging unit including the imaging element,
In the fixing step, it is preferable that the resin is cured after a resin made of a material that transmits light after curing is applied to the surface of the optical element or the imaging unit on which the optical element is fixed.

  According to said structure, there exists an effect which can provide an optical element in an imaging unit, without impairing the characteristic of an optical element.

  In the manufacturing method according to the present invention, it is preferable that in the fixing step, the resin is cured while visually confirming the positioning means through the lens holder.

  According to said structure, there exists an effect which can provide an optical element so that the center of an effective pixel area | region and the optical axis of an optical element may correspond substantially. In other words, the optical element can be provided with high positional accuracy with respect to the imaging element.

  It is preferable that the manufacturing method according to the present invention further includes an attachment step of attaching the lens holder to an image pickup unit including the image pickup device while visually checking the attachment means through the opening.

  According to the above configuration, since the position of the lens holder and the imaging unit can be finely adjusted while visually recognizing the positioning means through the lens holder, the lens holder and the imaging unit can be positioned with high accuracy.

  As a result, there is an effect that it is possible to manufacture an imaging device having performance as expected in the optical design. Moreover, the effect that the yield of an imaging device can be improved is also produced.

  In the manufacturing method according to the present invention, it is further preferable that the positioning means is recognized as a differential interference image in the attachment step.

  According to said structure, even if it is a case where it is difficult to visually recognize a positioning means through a lens holder, there exists an effect which can attach a lens holder with respect to an imaging unit accurately.

  As described above, the imaging apparatus according to the present invention has a lens holder in which the opening of the lens holder is designed so as to cover a part of the effective pixel region of the imaging device, and at least a part is visually recognized through the opening of the lens holder. And positioning means provided outside the effective pixel region.

  According to said structure, when positioning a lens holder using a positioning means, a positioning means can be visually recognized through the opening part of a lens holder. Thus, even when the lens holder covers a part of the effective pixel area of the image sensor, the optical axis of the imaging lens system held by the lens holder and the center of the effective pixel area of the image sensor The lens holder can be positioned so as to substantially match.

  Therefore, even if the light is incident at a position away from the optical axis of the imaging lens system, it can be imaged with high positional accuracy within the effective pixel region of the imaging element, so that a good image can be formed on the imaging element. There is an effect that can.

Embodiment 1
An embodiment of an imaging apparatus according to the present invention will be described below.

(Configuration of the imaging device 1)
The configuration of the imaging apparatus 1 will be described below with reference to FIGS. 1 (a) and 1 (b) and FIG. FIGS. 1A and 1B are diagrams showing the configuration of the imaging device 1, FIG. 1A is a cross-sectional view of the imaging device 1 showing a state where the imaging lens unit 30 is removed, and FIG. It is a top view of the imaging unit 10 when the imaging device 1 shown to a) is visually recognized through the opening part 26. FIG. FIG. 2 is a cross-sectional view of the imaging apparatus 1 showing a state where the imaging lens unit 30 is attached.

  As shown in FIGS. 1A and 1B and FIG. 2, the imaging apparatus 1 mainly includes three units of an imaging unit 10, a holding unit 20, and an imaging lens unit 30. These three units will be briefly described below.

(Configuration of the imaging unit 10)
The imaging unit 10 is a unit for receiving light that has passed through the imaging lens unit 30 and forming an image based on the received light. As shown in FIGS. 1A and 1B and FIG. 2, the imaging unit 10 includes a sensor chip (imaging device) 11, an effective pixel region 12, a sensor substrate 13, a transparent plate 14, and a unit case. 15, a bonding wire 16, an external connection terminal 17, an optical element 18, and a marker (positioning means) 18a.

  The sensor chip 11 that is electrically connected to the sensor substrate 13 converts the light received in the effective pixel region 12 into an electrical signal. The sensor chip 11 is specifically a solid-state image sensor, and a conventionally known solid-state image sensor such as a CCD or a C-MOS can be used. The converted electrical signal is output to the outside through the bonding wire 16 and the external connection terminal 17.

  In this specification and the like, the “effective pixel region” means a group of photodetectors that are actually used for imaging among a plurality of photodetectors arranged in a plane and converting light into an electrical signal. A group of photodetectors other than the effective pixel region is used to detect black and is called optical black.

  As long as the sensor substrate 13 is a flat substrate having an insulating property, the entire sensor substrate 13 may be made of an insulating material, or only the surface of the sensor substrate 13 may have an insulating property. . The material which comprises the sensor board | substrate 13 is not specifically limited, It can select from conventionally well-known materials, such as a ceramic and resin. Also, the method for imparting insulation to the surface of the sensor substrate 13 is not particularly limited, and a conventionally known method can be used.

  The unit case 15 includes a transparent plate 14 on the side facing the sensor substrate 13, that is, on the subject side, and an optical element 18 is formed on the transparent plate 14. That is, the space surrounded by the sensor substrate 11, the unit case 15, and the transparent plate 14 is a sealed space. The transparent plate 14 is damaged by the intrusion of dust or the like into the space and the effective pixel region 12 due to other members coming into contact with the effective pixel region 12 in manufacturing the imaging unit 10 or the imaging device 1. Is to prevent. The material of the transparent plate 14 is not particularly limited as long as it transmits light, and materials such as glass and resin can be used, for example.

  The optical element 18 and the marker 18a will be described in detail below.

(Configuration of holding unit 20)
The holding unit 20 is a unit for holding the imaging lens unit 30 and is attached to the imaging unit 10. As shown in FIGS. 1A and 2, the holding unit 20 mainly includes a lens holder 21, a focus adjustment screw portion 21 a, an actuator housing 25, an opening portion 26, and an autofocus (AF) mechanism 27. ing.

  The lens holder 21 has an opening 26 for attaching the imaging lens unit 30, and light passing through an imaging lens system 31 described below forms an image on the sensor chip 11 in the opening 26. A focus adjustment screw portion 21a for adjusting the position of the imaging lens unit 30 is provided. An actuator housing 25 is provided around the lens holder 21, and an AF mechanism 27 including a yoke 22, a magnet 23, and a coil 24 is built in the actuator housing 25.

  That is, since the AF mechanism 27 is provided around the imaging lens holding unit 21, the inner diameter of the opening 26, that is, the inner diameter of the focus adjustment screw portion 21 a is smaller than when the AF mechanism 27 is not provided. ing. As a result, as shown in FIG. 1B, when the effective pixel region 12 is viewed from the opening 26 side, the end portions (four corners) of the effective pixel region 12 are outside the inner diameter 21b of the focus adjustment screw portion. Become. Further, even if the optical element 18 is provided, it is outside the effective area 18 b of the optical element 18. Therefore, when the marker 18 a is provided in the vicinity of the four corners of the effective pixel region 12 as in Patent Document 1, for example, the marker 18 a cannot be visually recognized through the opening 26.

  In this specification and the like, the “effective area of the optical element” refers to the effective pixel area of the image sensor out of the light passing through the effective diameter that is the range that guides the light incident on the optical element to a desired position. It means an area through which light used for imaging passes.

(Configuration of the imaging lens unit 30)
The imaging lens unit 30 is a unit including an imaging lens system for forming incident light on the effective pixel region 12 of the sensor chip 11. As shown in FIGS. 1A and 2, the imaging lens unit 30 holds an imaging lens system 31 and an imaging lens system that form an image of light from a subject on the sensor chip 11, and also holds the imaging unit 30. An imaging lens system barrel 32 that can be attached to the focus adjustment screw portion 21a of the unit 20 is provided.

(Details of optical element 18)
Next, details of the optical element 18 will be described below.

  As shown in FIGS. 1A and 2, the optical element 18 formed on the transparent plate 14 is formed in a convex lens shape. As a result, the optical element 18 can correct the angle of the incident light so as to be close to parallel to the optical axis of the imaging lens system 31. In general, as the position incident on the imaging lens system 31 is further away from the optical axis (that is, the center of the effective pixel region 2), the angle incident on the effective pixel region 12 is further away from the vertical. The efficiency with which the effective pixel region 2 recognizes incident light and converts it into an electrical signal is highest when the angle of the incident light is perpendicular to the effective pixel region 12, and decreases as the distance from the vertical increases.

  Therefore, it is preferable to correct the angle of the incident light with respect to the effective pixel region 12 using the optical element 18 so as to be perpendicular to the effective pixel region 12. The optical element 18 preferably covers the entire surface of the effective pixel region 2 in order to increase the incident efficiency of light at the outer peripheral portion of the effective pixel region 2.

  The material of the optical element 18 is not particularly limited as long as the above-described correction can be realized. For example, as the material of the optical element 18, a photocurable resin that is cured by irradiation with ultraviolet rays, a thermosetting resin that is cured by application of thermal energy, and a thermoplastic resin can be used. The “energy curable resin” in this specification and the like is a general term for a photocurable resin and a thermosetting resin.

  In addition, when the reflow process that can reduce the mounting cost of the imaging unit 10 and is inexpensive and simple is adopted, as the material of the optical element 18, for example, at least one of an alkyl group and a phenyl group is used. Energy-curable resins such as silicon resin, silica-containing composite epoxy resin with hybrid carbon skeleton and silicon skeleton, modified acrylate resin, methacrylate composite resin, polysiloxane resin, silicone resin, silicone rubber, and transparent polyimide An energy curable resin having the heat resistance can be used.

  As described above, the optical element 18 can be easily formed into a desired shape by filling the mold with a resin and curing it, that is, by resin molding. The shape of the optical element 18 is not particularly limited as long as the light incident on the optical element 18 can be corrected so as to be substantially perpendicular to the effective pixel region 12. The optical element 18 may be either spherical or aspheric. For example, the optical element 18 may be formed as an aspherical lens having power, a lens having a Fresnel shape, or a diffractive lens having a fine relief shape. The resin molding of the optical element 18 will be described in detail in the second embodiment.

(Details of marker 18a)
Next, details of the marker 18a will be described below.

  The marker 18 a is a sign used mainly for determining the attachment position of the holding unit 20 when the holding unit 20 is attached to the imaging unit 21.

  In the imaging apparatus 1, when the holding unit 20 is attached to the imaging unit 10, usually, the markers provided at the four corners (corner portions) of the effective pixel area 12 are imaged with an image processing camera, and the effective pixel area 12 is processed. Recognize the center of Next, the inner diameter of the lens holder 21 is similarly imaged by another image processing camera, and the center of the inner diameter of the lens holder 65 is recognized. Then, after determining the relative positions of the two, the holding unit 20 is attached to the imaging unit 10.

  However, as described above, when the inner diameter of the lens holder 21 is reduced by providing the AF mechanism 27 and the like around the lens holder 21, the marker 18a is formed at the conventional position and the four corners ( The corner part) cannot be seen. Therefore, since adjustment by fine movement after the holding unit 20 is moved to the imaging unit 10 by coarse movement cannot be performed, positioning must be performed by an open loop.

  Therefore, a deviation of about 100 μm occurs between the center of the effective pixel region 12 and the center of the inner diameter of the lens holder 21, that is, the optical axis of the imaging lens system 31. If a deviation of about 100 μm occurs between the center of the effective pixel region 12 and the optical axis of the imaging lens system 31, the light incident on the peripheral end portion of the imaging lens system 31 protrudes from the effective image region 12. The peripheral light amount is reduced. Furthermore, when the image pickup apparatus 1 includes the optical element 18, not only the peripheral light amount is reduced but also the MTF is lowered due to the occurrence of aberrations in the optical system. Become.

  Therefore, in the present embodiment, as shown in FIG. 1B, the marker 18 a is a position where at least a part of the marker 18 a can be visually recognized through the opening 26 of the lens holder 21, and outside the effective pixel region 12. Is provided. In the present specification and the like, the “position that can be visually recognized through the opening 26” is a region within the range where the light beam that has passed through the opening 26 reaches in the member provided with the marker 18a. I mean. That is, for example, when the marker 18 a is provided on the optical element 18, it means that the optical element 18 is a region within a range where the light beam that has passed through the opening 26 can reach. Moreover, as long as the light passes through the opening 26, the angle of the light beam is not particularly limited, and may be a case where the light is irradiated from directly above the opening 26 or may be irradiated obliquely with respect to the opening 26. It may be the case.

  In the present embodiment, a case where light is irradiated to the image sensor 11 from the vertical direction will be described as an example. That is, the marker 18a has an inner diameter of a focus adjustment screw portion as shown in FIG. It is provided inside 21b. In the case of the imaging apparatus 1 provided with the optical element 18, as shown in FIG. 1B, the marker 18a may be provided at least partially within the effective area 18b of the optical element 18. Good.

  Since the marker 18a can be visually recognized through the lens holder 21 by providing the marker 18a at the position described above, the position of the holding unit 20 and the imaging unit 10 can be finely adjusted using the marker 18a. That is, when the holding unit 20 and the imaging unit 10 are attached, the deviation between the center of the effective pixel region 12 and the optical axis of the imaging lens system 31 can be suppressed within about 10 μm. Therefore, even if the light is incident at a position away from the optical axis of the imaging lens system 31, it can be imaged with high positional accuracy in the effective pixel region 12 of the sensor chip 11. Can be formed.

  Further, as shown in FIG. 1B, the marker 18 a is provided outside the effective pixel region 12. Therefore, even if the ambient light of the imaging lens system 31 is influenced by the marker 18a, the image quality does not cause a problem because it is a portion that is not originally recognized as an image.

  Furthermore, as shown in FIGS. 1A and 1B and FIG. 2, when the marker 18a is provided on the optical element 18, the optical characteristics of the optical element 18 such as refraction and reflection are not considered. The positions of the optical element 18 and the imaging lens system 31 can be determined with high accuracy. Further, since the optical element 18 is accurately positioned with respect to the sensor chip 11, even if the imaging device 1 includes the optical element 18, the light that has passed through the imaging lens system 31 can be used as the effective pixel area of the sensor chip 11. 12 can be imaged with high positional accuracy. That is, the imaging lens system 31, the optical element 18, and the sensor chip 11 can be accurately positioned. Therefore, a good image can be formed on the sensor chip 11 even in the imaging device 1 including the optical element 18.

  Of course, the marker 18 a is not necessarily provided on the optical element 18 as long as the marker 18 a is provided at a position that can be visually recognized through the lens holder 21. For example, as shown in FIG. 3, the marker 18 a may be provided on the transparent plate 14. At this time, since it is necessary to visually recognize the marker 18a through the optical element 18, it is preferable that the marker 18a is colored, for example, black to improve visibility. The marker 18 a provided on the transparent plate 14 masks the transparent plate 14 and then etches it with hydrofluoric acid or the like, or forms a groove structure on the transparent plate 14 using a grindstone, and a colored resin (for example, heat It can be formed by injecting a curable resin, a photocurable resin, or the like.

(Number of markers 18a)
The number of markers 18a is not particularly limited, but a plurality of markers 18a are preferably provided. When a plurality of markers 18 a are provided, the markers 18 a are preferably provided at positions that equally divide the circumference of a circle centered on the optical axis of the imaging lens system 31. Specifically, for example, when the number of markers 18a is two, the position where the circumference is evenly divided is a position where the markers 18a are spaced by 180 degrees with respect to the center of the optical axis. In this case, the positions are at intervals of 120 degrees. As a result, when the marker 18a is formed on the optical element 18, the internal strain of the marker 18a on the optical element 18 is evenly distributed as axial symmetry. Thereby, deformation of the optical element 18 can be suppressed uniformly and reliably. Furthermore, the center of the effective pixel region 12 can be recognized by a simple algorithm even in calculation by image processing. Note that the center of the effective pixel region 12 can also be referred to as the center of the optical element 18 when the optical element 18 is provided.

(Shape of marker 18a)
Next, the shape of the marker 18a will be described below with reference to FIGS. 4A to 4C are cross-sectional views schematically showing a cross section of the marker 18a, where FIG. 4A is a semicircular shape, FIG. 4B is a triangular shape, and FIG. 4C is a trapezoidal shape. It is. In FIGS. 4A to 4C, the hatching in the cross section is omitted.

  The shape of the marker 18a is not particularly limited. However, in the case of the imaging device 1 including the optical element 18, the shape of the marker 18a is a shape that gradually changes in order to reduce light scattering in the optical element 18 as much as possible. Preferably there is. The marker 18a is preferably resin-molded on the surface of the optical element 18 by the transfer mold 40 or 50 described in the second embodiment. Therefore, it is preferable that the shape of the marker 18a does not affect the releasability of the transfer mold 40 or 50.

  Therefore, the marker 18a preferably has a semicircular, triangular, or trapezoidal (rectangular) cross-sectional shape as shown in FIGS. That is, the three-dimensional shape is preferably a hemispherical shape, a cone shape, or a frustum shape. Thereby, scattering of light in the optical element 18 can be reduced as much as possible while ensuring releasability from the transfer mold 40 or 50 in resin molding. In addition, the shape of the bottom face of a cone and a frustum is not specifically limited. That is, it may be a circular cone or truncated cone with a bottom shape, or a polygonal pyramid or truncated pyramid.

  The cross-sectional dimensions of the marker 18a (the base width W and the height H in FIGS. 4A to 4C) are not particularly limited as long as they do not affect the molding of the optical element 18. . In order to obtain a dimension that does not completely affect the molding of the optical element 18, it is preferably smaller than the length of the shortest wavelength in the wavelength band to be used. That is, it is preferable to form the marker 18a as a fine structure. For example, when the wavelength band used is a visible light region (short wavelength side: 380 to 400 μm, long wavelength side: 750 to 800 μm), the base width W and the height H are 400 nm or less. However, this numerical value is further increased in consideration of a reduction in the light amount of the lens system due to the marker 18a.

  For example, when the optical element 18 is applied to a camera module using an imaging element, a lens having a diaphragm F3.4 and a focal length of about 4 mm is used, and an optical surface is located at a back focus of 300 μm from the imaging surface. The size of the base width W and the height H that cause a light amount decrease of about 2% that hardly affects is about 10 μm. Therefore, it is preferable that the numerical values of the bottom width W and the height H of the cross section of the marker 18a have an upper limit of about 1/5, which is a value having a sufficient margin with respect to 10 μm. That is, when the base width W and the height H are dimensions smaller than 2 μm, the marker 18 a does not affect the optical characteristics of the optical element 18. Further, the lower limit value is not particularly limited, but when the antireflection layer 19 described below is provided, the lower limit value needs to be larger than the thickness of the antireflection layer 19.

  In addition, when the marker 18a is observed using an image processing camera, the marker 18a may be hardly recognized with normal shading. In that case, it is preferable to change the phase change information to the intensity change information by taking an image of the marker image with an image processing camera through a differential filter or the like, or differentiating the image after taking an image using software.

  However, the low frequency component of the spatial frequency that is handled on the axis of the camera module may be affected by the influence of scattering by the marker 18a. In this case, as a result, the image quality is deteriorated such that the contrast of the image quality is lowered. In such a case, it is preferable to form the marker 18a in a region away from the optical axis of the imaging lens system 31.

(Relationship between marker 18a and optical element 18)
Moreover, when providing the marker 18a in the optical element 18, it is preferable that the difference of the transmittance | permeability of the marker 18a and the transmittance | permeability of the area | region of the optical element 18 in which the marker 18a is not formed is 4% or more. Specifically, as shown in FIGS. 5A and 5B, for example, by coloring only the marker 18a in black, the difference in transmittance can be set to 4% or more. As a result, a difference in transmittance between the marker 18a and the area other than the marker 18a appears greatly, so that the marker 18a is easily visible. Therefore, since image processing by normal photographing can be performed using an image processing camera, the yield of the sensor chip 11 can also be improved. Furthermore, the image processing system can be made inexpensive. 5A and 5B are diagrams illustrating the imaging unit 10 when the marker 18a is black, FIG. 5A is a cross-sectional view of the imaging unit 10, and FIG. 2 is a plan view of a unit 10. FIG.

(Modification of Embodiment 1)
On the optical element 18, an antireflection layer 19 may be formed as shown in FIG. FIG. 6 is a cross-sectional view showing the configuration of the optical element 18 on which the antireflection layer 19 is formed.

  The structure of the antireflection layer 19 may be a single layer structure or a multilayer structure. When the antireflection layer 19 has a single-layer structure, deformation (for example, cracking or peeling) of the antireflection layer 19 in a high temperature environment can be suppressed. In addition, an increase in internal stress can be prevented. Furthermore, the process time for film formation can be shortened, and the manufacturing process of the antireflection layer 19 can be simplified, so that the manufacturing cost can be reduced.

The antireflection layer 19 may be made of a material having a refractive index lower than that of the optical element 18 (synthetic resin applied to resin molding). In this case, as a material of the antireflection layer 19, for example, magnesium fluoride (MgF ₂ ) having a refractive index n = 1.38 can be used.

  A suitable temperature for depositing magnesium fluoride as the antireflection layer 19 is 200 ° C. or higher. Therefore, when the antireflection layer 19 having a single layer structure is formed, the synthetic resin used for the optical element 18 is preferably a material that can withstand high temperatures. Examples of such a resin include a heat-resistant resin such as a silicone resin having an alkyl group having a Si—O—Si silica bond and a phenyl group, or an inorganic / organic hybrid silicone resin in which a carbon skeleton and a silicone skeleton are hybridized. Can be mentioned.

  The film thickness (optical film thickness nd) varies in accordance with the optical characteristics and desired reflection characteristics of the optical element 18, but as one guideline, the refractive index n × the optical film thickness nd of the material of the antireflection layer 19. However, it is preferable to set so as to be 1/4 of the design wavelength λ.

Further, when the antireflection layer 19 has a multilayer structure, the reflectance can be significantly reduced. More specifically, a high refractive index layer made of a material having a refractive index higher than that of the optical element 18 (resin applied to resin molding) and a low refractive index made of a material having a low refractive index. By adopting a laminated structure in which the rate layers are alternately laminated, the antireflection characteristics can be further improved as compared with the case of the single layer structure. For example, in the wavelength band to which the optical element 18 is applied, excellent antireflection characteristics that can be applied even when it is necessary to have excellent antireflection characteristics as an extremely low reflectance of 1% or less are realized. be able to. As the high refractive index layer, for example, a high refractive index material mainly composed of titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), or a mixture thereof can be used. Further, the above-described magnesium fluoride can be used as the low refractive index layer.

  Each film thickness (optical film thickness nd) of the high refractive index layer and the low refractive index layer is the same as in the case of the single layer structure, and varies depending on the optical characteristics and desired reflection characteristics of the optical element 18. As one guideline, it is preferable to set the refractive index n × the optical film thickness nd of the material of the antireflection layer 19 to be ¼ of the design wavelength λ.

  A base layer (not shown) may be formed between the antireflection layer 19 and the surface of the optical element 18. The base layer made of an inorganic material having good adhesion to the material of the optical element 18 and excellent in chemical resistance and abrasion resistance firmly bonds the antireflection layer 19 and the optical element 18 together. Can be improved. Thereby, peeling of the antireflection layer 18 due to thermal expansion can be suppressed.

  As the material of the underlayer, the refractive index of the low refractive index material is in the range of the refractive index of the material used as the optical element 18 made of synthetic resin, and the low refractive index material is excellent in chemical resistance and wear resistance. It is preferable that the optical element 18 made of a synthetic resin has good adhesion and has a small amount of light scattering and light absorption when used as an underlayer. Specifically, a low refractive index material having a refractive index n = 1.49 to 1.59 mainly composed of silicon oxide (SiOx (2> x> 1)) can be given.

  Moreover, it is preferable that the film thickness of a base layer is about 200-300 nm. This makes it possible to obtain a highly reliable optical element 18 that is excellent in heat resistance, adhesion, wear resistance, and chemical resistance, and that does not deteriorate optical characteristics. When the base layer and the antireflection layer 19 are provided, the height H of the marker 18a needs to be slightly higher than the thickness of the base layer and the antireflection layer 19 laminated.

Since the antireflection layer 19 is formed by sputtering or vapor-depositing an inorganic oxide film, it hardly adheres to the marker 18a having an inclined surface. That is, a difference in reflectance can be easily generated between the marker 18a and a region other than the marker 18a. When the marker 18a is imaged by the reflectance difference, that is, the transmittance difference using an image processing camera, the recognition rate of the marker 18a can be improved. In the case of a single layer of magnesium fluoride (MgF ₂ ), the transmittance is only about 4% from the difference in refractive index, but the image processing can sufficiently improve the recognition rate.

(Additional notes)
Note that the imaging device 1 may include a microlens (not shown) on the effective pixel region 12. Since the microlens is provided on the effective pixel region 12, the angle of light incident on the effective pixel region 12 can be corrected, and the light incident on the effective pixel region 12 can be corrected to an optimum state.

  When the imaging unit 10 is applied to the photographing apparatus 1, the optical system (the optical element 18, the microlens and the photographing diagram, etc.) of the whole photographing apparatus 1 is also taken into consideration in consideration of the formation position of the microlens. It is preferable to perform (shape and arrangement).

  The imaging device 1 may include an infrared cut filter (not shown) between the transparent plate 3 and the optical element 18.

  As described above, when the imaging unit 10 is built in a photographing apparatus such as a normal camera or a video recorder camera, it is preferable to avoid that infrared rays unnecessary for image formation are incident on the sensor chip 11. In order to avoid the incidence of infrared rays on the sensor chip 11, it is necessary to reflect or absorb (cut) the infrared rays. In the present embodiment, a case where a dielectric multilayer film that reflects infrared rays is formed as an infrared cut filter between the transparent plate 3 and the optical element 18 will be described as an example.

  The dielectric multilayer film changes the wavelength range of reflected light according to the incident angle of light. For this reason, when a dielectric multilayer film is formed on a curved surface (for example, a lens or the like), the wavelength of the reflected light is different between the vicinity of the center and the vicinity of the end portion. Therefore, the dielectric multilayer film is preferably formed on the flat transparent plate 14. The dielectric multilayer film is preferably provided on the surface of the transparent plate 14 on the side where the optical element 18 is formed. This is to prevent the formed image quality from being deteriorated by adhering to the effective pixel region 12 when the dielectric multilayer film is peeled off.

  Further, when the dielectric multilayer film is formed only on one surface of the transparent plate 14, the transparent plate 14 is warped due to the film stress of the dielectric multilayer film. Therefore, it is preferable that the dielectric multilayer film formed on the transparent plate 14 is divided into small pieces by, for example, dicing. By dividing the dielectric multilayer film into small pieces, the film stress can be released (reduced). Thereby, it is possible to prevent the formed image quality from deteriorating.

  The dielectric multilayer film that reflects infrared light is preferably a multilayer film in which high refractive index layers and low refractive index layers are alternately formed. Such a dielectric multilayer film can be formed by a conventionally known film forming method such as sputtering or vapor deposition.

Specific examples of the material constituting the high refractive index layer include TiO ₂ (n = 2.4), Ta ₂ O ₅ (n = 2.1), and Nb ₂ O ₅ (n = 2.2). , And ZrO ₂ (n = 2.05). Moreover, as a material which comprises a low refractive index layer, specifically, SiO ₂ (n = 1.46), Al ₂ O ₃ (n = 1.63), and MgF ₂ (n = 1.38). ) And the like. Note that n in the parentheses indicates a refractive index with respect to light having a wavelength of 500 nm which a layer formed of a single material has. Note that the refractive index shown in parentheses varies depending on the wavelength of incident light.

  The high refractive index layer and the low refractive index layer in the dielectric multilayer film are preferably formed to have the same optical film thickness. If the design wavelength λ is near the center of the wavelength range of the light to be cut, the optical film thickness nd can be expressed as ¼λ. A high refractive index layer having an optical film thickness nd is represented by 1H, and a low refractive index layer having an optical film thickness nd is represented by 1L. In the case of “(0.5H, 1L, 0.5H) S”, there are two high refractive index layers having a thickness of 1 / 8λ, and a thickness of 1 / 4λ between the two layers. This means that there are one or more pairs in which the low refractive index layer having the above is formed. Note that “S” means the number of stacks, and indicates how many layers in the parentheses are stacked.

  Actually, the laminated dielectric multilayer film is composed of 2S + 1 layers, and as the value of S increases, the rising characteristic (steepness) that changes from reflection to transmission can be increased. The value of S is preferably selected from the range of 3-20.

  Light having a wavelength that can be cut can be determined from the refractive index and the rising characteristic of each layer constituting the dielectric multilayer film. The dielectric multilayer film for cutting (reflecting) infrared rays is preferably formed as a laminated structure of about 40 to 60 layers.

[Embodiment 2]
A method for manufacturing an imaging device according to the present invention will be described below as a second embodiment. In addition, about the member similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The manufacturing method of the imaging device according to the present embodiment includes a holding unit 20 (lens holder) forming step and a marker 18a (positioning means) forming step.

(Holding unit 20 forming step)
The holding unit 20 forming step is a step of designing the opening 26 of the lens holder 21 so that the lens holder 21 covers a part of the effective pixel region 12 of the sensor chip 11. That is, as described in the first embodiment, the holding unit 20 including, for example, the AF mechanism 27 is formed around the lens holder 21.

(Marker 18a formation process)
The marker 18a forming step is a step of forming at least a part of the marker 18a at a position where it can be visually recognized through the opening 26 of the lens holder 21. Thereby, when adjusting the position of the holding unit 20 and the imaging unit 10, the marker 18 a can be visually recognized through the lens holder 21. Therefore, even if the light is incident at a position away from the optical axis of the imaging lens system 31, it can be imaged with high positional accuracy in the effective pixel region 12 of the sensor chip 11. Can be formed.

  In the step of forming the marker 18a, in the case of the imaging device 1 including the optical element 18, it is preferable to form the marker 18a on the optical element 18. Moreover, when forming the marker 18a in the optical element 18, it is preferable to shape | mold the optical element 18 and the marker 18a simultaneously. By molding the optical element 18 and the marker 18a at the same time, the marker 18a can be molded more easily and more accurately in mold accuracy than molding the marker 18a separately from the optical element 18 and then bonding it to the optical element 18. . In addition, the optical element 18 including the marker 18a provided with high positional accuracy with respect to the optical axis of the optical element 18 can be manufactured with high productivity and at low cost. When the optical element 18 and the marker 18a are molded simultaneously, the marker 18a forming step preferably includes a filling step and a curing step described below.

(Filling process)
The filling process includes an optical element transfer surface (optical element transfer portion) 40b or 50b for forming the optical element 18, a transfer groove (marker transfer portion) 40a or a transfer protrusion (marker transfer portion) 50a for forming the marker 18a. The transfer mold 40 or 50 is made of a resin having fluidity.

  The resin that can be used for molding the optical element 18 and the marker 18a is not particularly limited as long as it has a property of transmitting light after curing. Specifically, it is preferable to use an energy curable resin or a thermoplastic resin such as a photocurable resin or a thermosetting resin. When energy curable resin is used, an optical element 18 having a desired shape (for example, an aspheric lens having power, a lens having a Fresnel shape, a diffractive lens having a fine relief shape, etc.) is easily formed. can do. Further, when a thermoplastic resin is used, a large amount of the optical element 18 on which the marker 18a is formed can be manufactured at a low cost.

  The details of the transfer mold 40 or 50 will be described in detail below.

(Curing process)
The curing step is a step of curing the resin filled in the transfer mold 40 or 50. The specific curing step is preferably set as appropriate depending on the type of resin used. For example, when using a photocurable resin, it is preferable to be a step of irradiating the resin with light such as ultraviolet rays, visible light, or infrared rays, and when using a thermosetting resin, it is a step of heating the resin. Preferably, when a thermoplastic resin is used, it is preferably a step of cooling the resin.

(Details of transfer molds 40 and 50)
The transfer molds 40 and 50 will be described below with reference to FIGS. 7 (a) and 7 (b). 7A and 7B are cross-sectional views schematically showing the shapes of the transfer molds 40 and 50, and FIG. 7A is a transfer mold for forming the marker 18a as a protrusion. ) Is a transfer mold for forming the marker 18a as a groove.

  The transfer mold 40 includes an optical element transfer surface 40b for forming the optical element 18 and a transfer groove 40a for forming the marker 18a. That is, for example, when the optical element 18 is an aspheric lens, the optical element transfer portion 40b has a relationship between the aspherical shape and the positive and negative, and similarly, the transfer groove 40a is transferred to the optical element 18 by the marker 18a. And positive / negative relationship.

  As the mold material of the transfer mold 40, a sintered material such as martensitic stainless steel, oxygen-free copper, or tungsten carbide can be used.

  Similarly to the transfer mold 40 shown in FIG. 7A, the transfer mold 50 includes an optical element transfer surface 50b that transfers and molds the optical element 18, and a transfer protrusion 50a that molds the marker 18a. That is, for example, when the optical element 18 is an aspherical lens, the optical element transfer surface 50b has a positive and negative relationship with the aspherical shape, and the transfer transfer protrusion 50a is similarly transferred to the optical element 18 as a marker. 18a and positive / negative relationship.

  Next, the transfer mold 50 is preferably made of a mold material that transmits light. Specific examples include glass materials such as quartz and BK7, and transparent resin materials such as transparent polycarbonate, acrylic, and ZEONEX. Since the transfer mold 50 is made of a mold material that transmits light, the effective pixel region 12 can be visually recognized through the transfer mold 50 filled with resin. As a result, the optical element 18 can be provided so that the center of the effective pixel region 12 and the optical axis of the optical element 18 substantially coincide with each other.

  By using the transfer molds 40 and 50 capable of transferring the marker 18a simultaneously with the optical element 18, the production efficiency can be improved as compared with the case where both are transferred separately.

  Further, it is not necessary to align the both, and the productivity of the optical element 18 provided with the markers 18a with high accuracy can be improved. Therefore, since the optical element 18 provided with the marker 18a can be manufactured by one molding process, the highly accurate optical element 18 can be molded at low cost.

(Method for manufacturing transfer molds 40 and 50)
Next, a method for manufacturing the transfer molds 40 and 50 will be described below. In general, the manufacture of molds requires very high precision and high definition technology. Similarly, the transfer dies 40 and 50 need to be manufactured with high precision and high definition. Further, since the transfer molds 40 and 50 are provided with the transfer groove 40a and the transfer protrusion 50a, they must be manufactured with higher accuracy and higher definition.

  A method for manufacturing the transfer mold 40 will be described below with reference to FIGS. FIGS. 8A to 8G are views showing an example of a method for manufacturing the transfer mold 40, FIG. 8A is a view showing a mold material 41, and FIG. 8B is a view showing the formation of an optical element transfer surface 40b. (C) is a view for forming the photoresist 43, (d) is a view for forming the photosensitive resist portion 44, (e) is a view for removing the photosensitive resist portion 44, (f) is a view for forming the transfer groove 40a, and (g) is a view for removing the photoresist 43. FIG.

  First, a mold material 41 for forming the transfer mold 40 is prepared (FIG. 8A). An optical element transfer surface 40b is formed by machining the prepared mold material 41 using an ultra-precision lathe or ultra-precision grinder (FIG. 8B).

  Next, a photoresist 43 is applied to the optical element transfer surface 40b and prebaked at a temperature of about 100 ° C. (FIG. 8C). Subsequently, the exposure light 45 is applied to the photoresist 43 to expose (expose) a part of the photoresist 43 corresponding to the transfer groove 40a. Then, a removable photoresist resist portion 44 is formed on the exposed photoresist 43 to form an exposure mask pattern (FIG. 8D). The photoresist 43 may be a positive type or a negative type. That is, it can be appropriately selected according to the exposure method and the shape of the exposure mask pattern corresponding to the transfer groove 40a. In the present embodiment, a case where a positive photoresist is used will be described as an example.

  After the exposure, the photoresist 43 (exposure mask pattern) is developed to remove the photosensitive resist portion 44 and form a resist mask 45 having an opening corresponding to the transfer groove 40a. After development, the resist mask 46 (unphotosensitive resist portion) is improved in corrosion resistance by rinsing with pure water and post-baking at a temperature of about 100 to 200 ° C. (FIG. 8E).

  Next, the surface of the mold material is etched (patterned) using an etching agent 47 using the resist mask 46 with improved corrosion resistance as a mask. Thereby, the transfer groove 40a can be formed (FIG. 8F). As a method for forming the transfer groove 40a, specifically, a method of immersing the metal material 41 in the etching agent 47 can be exemplified. The etching agent 47 can be appropriately selected according to the mold material 41 to be used. For example, when stainless steel or oxygen-free copper is used as the mold material 41, it is preferable to use a ferric chloride solution or the like.

  Finally, the resist mask 46 is removed using acetone or the like (FIG. 8G). Thereby, the transfer mold 40 can be formed. After removing the resist mask 46, gold (Au), chromium nitride (CrN), titanium nitride (on the optical element transfer surface 40b is formed on the optical element transfer surface 40b in order to improve releasability from the optical element 18 (molded product) to be formed. A release film (not shown) such as TiN) or diamond-like carbon (DLC) may be formed with a film thickness of about several nm to several tens of nm.

  As described above, in the method for manufacturing the transfer mold 40, the transfer groove 40a for forming the marker 18a is formed by patterning. Thereby, even if the shape of the optical element transfer surface 40b is a curved shape, the transfer groove 40a can be easily formed. Further, since machining is not used for forming the transfer groove 40a, the transfer groove 40a can be formed without causing distortion (damage, damage) or the like due to machining. That is, since the formation of the transfer groove 40a does not affect the shape of the optical element transfer surface 40b, the high-precision and high-definition transfer mold 40 can be manufactured easily and inexpensively.

  Next, a method for manufacturing the transfer mold 50 will be described below with reference to FIGS. 9 (a) to 9 (g) and FIGS. 10 (a) to 10 (c). FIGS. 9A to 9G are views showing an example of a manufacturing method of the master die 54 used for forming the transfer die 50, FIG. 9A is a view showing the mold material 51, and FIG. It is a figure which forms the optical element transfer surface formation surface 52, (c) is a figure which forms the photoresist 43, (d) is a figure which forms the photosensitive resist part 44, (e) is a photosensitive resist part. 44 (f) is a view for removing the marker 43, (f) is a view for forming the marker forming portion 53, and (g) is a view for removing the photoresist 43. FIG. That is, the manufacturing method of the master mold 54 shown in FIGS. 9A to 9G is the same as that shown in FIGS. 8A to 8G except that the optical element transfer surface forming surface 52 is formed in FIG. This is the same as the manufacturing method of the transfer mold 40 shown. Therefore, in the present embodiment, FIGS. 9A to 9G are not described in detail.

  FIGS. 10A to 10C are diagrams showing an example of a manufacturing method for forming the transfer die 50 using the master die 54 formed by the manufacturing method shown in FIGS. 9A to 9G. (A) is a figure which sets the preform 55 with respect to the master type | mold 54, (b) is a figure which shape | molds the preform 55 using the master type | mold 54, (c) is a figure which separates the master type | mold 54. FIG. FIG.

  First, after setting the master die 54 to the die set 56, the softening temperature (generally 400 to 600 ° C.) of the preform 55 (glass material) that uses the master die 54 as a material for the transfer die 50 together with the die set 56. ) Until the temperature rises. Then, the preform 55 is set on the master die 54 in the die set 56 with high accuracy. (FIG. 10 (a)).

  Next, the master die 54 is pressed against the preform 55, and the preform 55 is gradually subjected to high temperature and high pressure to form the shape of the transfer die 50 (FIG. 10B). When air remains in the marker forming portion 53 of the master die 54, the preform 55 does not enter the marker forming portion 53, and the shape of the transfer protrusion 50a of the transfer die 50 can be formed. Can not. Therefore, the step shown in FIG. 10B is preferably performed in a vacuum.

  Subsequently, when the shape of the transfer mold 50 is formed, the master mold 54 is released from the transfer mold 50, the transfer mold 50 is gradually cooled, and the internal stress accumulated during the molding of the transfer mold 50 is gradually increased. Open. Thereby, the transfer mold 50 can be formed (FIG. 10C).

  In addition, the manufacturing method of the transfer mold 50 is not limited to the above-described method, and a glass material or a transparent resin material may be directly processed using an ultraprecision lathe or an ultraprecision grinder. Which method is used is preferably selected as appropriate according to the environment surrounding the manufacturing at that time.

(Method of manufacturing optical element 18 using transfer mold 50)
Next, a method for forming the optical element 18 provided with the marker 18a using the transfer mold 50 will be described.

  11A to 11D are views showing an example of a method for forming the optical element 18 using the transfer mold 50, FIG. 11A is a view showing a filling process, and FIG. FIG. 4 is a diagram for aligning the transfer mold 50 and the effective pixel region 12, (c) is a diagram illustrating a curing process, and (d) is a diagram for releasing the transfer mold 50.

  Using the rod 60 of a mounter device (not shown), the imaging unit 10 is vacuum fixed (vacuum chucking) so that the transparent plate 14 faces downward. At the same time, the resin 61 having fluidity is filled in the depression (optical element transfer surface 50b) of the transfer mold 50 formed to transfer the surface shape of the optical element 18 (FIG. 11A). Here, in this embodiment, a case where a photocurable resin that is cured by irradiation with ultraviolet rays is used as a resin for molding the optical element 18 will be described as an example.

  Next, the image processing camera 62 is used to image the shape (planar shape, center position, etc.) of the effective pixel region 12 from the transfer mold 50 side. Then, the captured image of the effective pixel region 12 is processed by the image processing apparatus. Specifically, the center of the transfer mold 50 that has been recognized in advance by the image processing apparatus and the center of the effective pixel region 12 subjected to the image processing are aligned with at least one of the X-axis direction and the Y-axis direction (see FIG. 11 (b)).

  After the alignment is completed, the transfer mold 50 filled with the resin 61 is fixed in contact with the transparent plate 14. After fixing the transfer mold 50, the UV lamp 63 is turned on and the resin 61 filled in the transfer mold 50 is cured by irradiating ultraviolet rays (FIG. 11C).

  After the resin 61 is sufficiently cured, that is, after the optical element 18 is molded, the transfer mold 50 is released from the optical element 18 (FIG. 11D).

  Note that a silane coupling agent may be applied to the transparent plate 14 prior to the step shown in FIG. By applying a silane coupling agent to the transparent plate 14, the adhesive force between the resin 61 for molding the optical element 18 and the inorganic transparent plate 14 can be enhanced. The silane coupling agent applied to the transparent plate 14 is not particularly limited as long as it can improve the chemical adhesive force with the resin 61, and is appropriately selected from conventionally known silane coupling agents according to the properties of the resin used. That's fine.

  For example, when the resin 61 is a modified acrylate resin or a methacrylate composite resin, an amino or methacryloxy silane coupling agent can be used. In the case where the resin 61 is a polysiloxane resin, a silica-containing composite type epoxy resin, a silicone resin, a silicone rubber, and a transparent polyimide, amino-based and epoxy-based silane coupling agents can be used.

  Application of the silane coupling agent is preferably performed as follows. First, the silane coupling agent is diluted to about 1% with an organic solvent such as isopropyl alcohol. Next, the surface on which the diluted silane coupling agent is to be applied is dipped. After the dipped coated surface is dried, it is baked at a temperature of about 100 ° C. Thereby, a silane coupling agent can be applied. In addition to the method described above, a silane coupling agent may be applied using a conventionally known method.

  In addition, as shown in FIGS. 5A and 5B, the optical element 18 in which the difference between the transmittance of the marker 18a and the transmittance of the region other than the marker 18a is increased is shown in FIGS. After the optical element 18 is manufactured by the method shown in Fig. 1, it can be easily manufactured by applying a small amount of black energy curable resin to the marker 18a formed on the optical element 18 and then curing it by applying energy. .

(Method of manufacturing optical element 18 using transfer mold 40)
Next, a method of molding the optical element 18 using the transfer mold 40 will be described below with reference to FIGS. 12 (a) to 12 (e) and FIGS. 13 (a) to 13 (c).

  12A to 12E are views showing an example of a method for manufacturing the optical element 18 with the marker 18a using the transfer mold 40, and FIG. 12A shows a state where the die set 70 is opened. (B) is a figure which shows the state (filling process and hardening process) which clamped the die set 32 and inject | poured resin, (c) has completed resin shaping | molding and releases the optical element 18. FIG. It is a figure which shows a state, (d) is a figure which shows the state which forms an antireflection layer in the resin-molded optical element 18, (e) is a figure which shows the molded optical element 18. FIG.

  First, the die set 70 provided with the transfer mold 40 is opened (FIG. 12A). The die set 70 is composed of an upper mold 70a and a lower mold 70b for holding the transfer mold 40 for molding the optical element 18, and the upper mold 70a has a gate 71 for injecting resin. Yes.

  Subsequently, after the die set 70 is clamped, resin is injected from the gate 71 (FIG. 12B). There are various methods for injecting the synthetic resin, but it is preferable to use injection injection in consideration of molding accuracy and mass productivity.

  Here, when a thermoplastic resin is used as the resin, a molten resin of about 150 ° C. is injected into the die set 70 whose temperature is adjusted to about 80 ° C. The injected molten resin is cooled and solidified when it comes into contact with the transfer mold 40. Thereby, the optical element 18 and the marker 18a are molded. Further, when a thermosetting resin is used as the resin, a resin in a liquid state of 80 ° C. or less is injected into the die set 70 whose temperature is adjusted to 150 to 200 ° C. As a result, the injected liquid resin undergoes a polymerization reaction, and the optical element 18 and the marker 18a are molded.

  In FIG. 12B, the optical element 18 in a state where the gate mark 18 c is connected is molded from the structure of the die set 70.

  Next, when the resin molding by the die set 70 is completed, the molded optical element 18 is released from the die set 70 (FIG. 12C). Note that, after being released from the die set 70, the gate mark 18c is removed.

The optical element 18 whose shape has been adjusted by removing the gate mark 18c is placed in the vapor deposition chamber 72, and the antireflection layer 19 is formed by vapor deposition using the antireflection layer forming nozzle 73 (FIG. 12D). )). Specifically, after vacuum-depositing the deposition chamber 72, a vacuum state of about 1.0 × 10 ⁻⁴ Torr is maintained in a state where oxygen gas is introduced. Then, the antireflection layer target component 19a such as magnesium fluoride, titanium oxide, or zirconium oxide is appropriately heated by a resistance heating method or an electron beam heating method to be evaporated. Subsequently, the antireflection layer component 19a is applied to the optical element 18, and the antireflection layer 19 is formed (evaporated). After the antireflection layer 19 is formed, the vapor deposition chamber 72 is pressurized to atmospheric pressure, opened, and the optical element 18 is taken out.

  By forming the antireflection layer 19 by vapor deposition, the film thickness of the antireflection layer 19 can be accurately controlled. Thereby, the optical element 18 having high-precision optical characteristics can be obtained. As described above, since the antireflection layer 19 is hardly deposited on the marker, the transmittance difference between the marker 18a and the region other than the marker 18a can be 4% or more. Thereby, the optical element 18 as shown in FIG. 12E can be molded.

  Next, a method for fixing the extracted optical element 18 will be described below with reference to FIGS. FIGS. 13A to 13C are diagrams showing an example of a method for fixing the optical element 18 to the imaging unit 10. FIG. 13A is an adhesive resin 80 for bonding the optical element 18 and the transparent plate 14. (B) is a diagram for aligning the center of the optical element 18 and the center of the effective pixel region 12, and (c) is a diagram for curing the adhesive resin 80.

  First, using the rod 60 of a mounter device (not shown), the imaging unit 10 is vacuum fixed (vacuum chucking) so that the transparent plate 14 faces downward. At the same time, an adhesive resin 80 having fluidity is applied between the optical element 18 and the transparent plate 14 (FIG. 13A).

  Here, in the present embodiment, a photocurable resin that is cured by irradiation with ultraviolet rays is described as an example of the adhesive resin 80, but the present invention is not limited to this. For example, an energy curable resin such as a thermosetting resin that is cured by heat may be used.

  Next, the image processing camera 62 is used to image the shape (planar shape, center position, etc.) of the effective pixel region 12 from the optical element 18 side. Then, the captured image of the effective pixel region 12 is processed by the image processing apparatus. Specifically, the center of the optical element 18 recognized in advance by the image processing apparatus and the center of the effective pixel area subjected to image processing are aligned with at least one of the X-axis direction and the Y-axis direction (FIG. 13). (B)).

  As in the case of using the transfer mold 50 described above, a silane coupling agent may be applied to the transparent plate 14 prior to FIG.

  After the alignment is completed, the optical element 18 coated with the adhesive resin 80 is fixed in contact with the transparent plate 14. After the optical element 18 is fixed, the UV lamp 63 is turned on and ultraviolet irradiation is performed (FIG. 13C). Thereby, the optical element 18 can be attached to the imaging unit 10.

  It should be noted that by manufacturing the optical element 18 using the transfer mold 40 or 50 as described above, complicated aspherical lenses having power, lenses having a Fresnel shape, and diffractive lenses having a fine relief shape are used. The optical element 18 having a shape can be easily molded. Further, since the optical element 18 can be fixed while being positioned so that the center of the optical element 18 is accurately opposed to the center of the effective pixel region 12, an imaging apparatus capable of forming an image with a small reduction in peripheral light amount and high resolution. 1 can be provided.

(Attaching the holding unit 20)
Finally, a method for assembling the imaging device 1 by attaching the imaging unit 10, the holding unit 20, and the imaging lens unit 30 constituting the imaging device 1 will be described below. An attachment process for attaching the holding unit 20 to the imaging unit 10 will be described below with reference to FIGS. Further, the attachment process of attaching the holding unit 20 to the imaging unit 10 can be rephrased as the attachment process of attaching the lens holder 21 to the imaging unit 10.

  FIGS. 14A to 14C are diagrams showing an attaching process for attaching the holding unit 20 to the imaging unit 10, FIG. 14A is a diagram in which the holding unit 20 and the imaging unit 10 are imaged, and FIG. FIG. 7 is a diagram in which the unit 20 is aligned, and FIG.

  First, the actuator housing 25 of the holding unit 20 is chucked by using a rod 81 of a mounter device (not shown), and is used for focus adjustment provided in the opening 26 of the lens holder 21 by using an image processing camera 90b. The inner diameter of the screw portion 21a is imaged. Then, image processing is performed on the innermost diameter of the imaged opening 26 by the image processing device. Also, the position of the marker 18a provided on the optical element 18 is simultaneously imaged using the image processing camera 90a, and the optical axis of the optical element 18 is recognized from the position of the marker 18a using the image processing apparatus (FIG. 14 ( a)).

  Next, after confirming the relative position between the two and roughly moving the holding unit 20 on the imaging unit 10, the marker 18a provided on the optical element 18 and the focus adjustment screw are provided in real time using the image processing camera 90a. The inner diameter of the part 21a is imaged. Then, the optical axis of the optical element 18 and the center of the inner diameter of the focus adjustment screw portion 21a are finely moved in the X-axis direction and / or the Y-axis direction (FIG. 14B). Note that the optical axis of the imaging lens system 31, the optical axis of the optical element 18, and the center of the effective pixel region 12 are matched by aligning the optical axis of the optical element 18 with the center of the inner diameter of the focus adjustment screw portion 21a. Can be substantially matched.

  Subsequently, the holding unit 20 and the imaging device 10 that have been aligned are fixed (FIG. 14C)).

  Finally, as shown in FIG. 15, focus adjustment of the imaging lens system barrel 32 is performed with respect to the effective pixel region 12 of the imaging device 1. Thereby, the imaging lens unit 30 is attached to the imaging unit 10 to which the holding unit 20 is attached, and the imaging device 1 is completed. FIG. 15 is a diagram in which the imaging lens unit 30 is attached to the holding unit 20.

  As described above, by attaching the holding unit 20 to the imaging unit 10, the positions of the holding unit 20 and the imaging unit 10 can be finely adjusted while viewing the marker 18 a through the lens holder 21. Thereby, the holding unit 20 and the imaging unit 10 can be accurately positioned. In addition, since the imaging device 1 in which the holding unit 20 and the imaging unit 10 are accurately positioned can obtain the performance as expected in the optical design, the yield of the imaging device 1 can be improved.

  If the difference between the transmittance of the marker 18a and the transmittance of the region other than the marker 18a cannot be 4% or more due to a margin during production, and the marker 18a cannot be recognized, a differential interference image may be used. . Accordingly, even when the marker 18a is hardly visible, the holding unit 20 and the imaging unit 10 can be attached with high accuracy.

  Note that the optical element 18 is not necessarily provided, and may be an imaging device that does not include the optical element 18. In this case, the marker 18a is preferably formed on the sensor chip 1 by a conventionally known method.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

(Additional notes)
In addition, this invention can also be described as follows.

(First configuration)
A solid-state image pickup device in which an optical element is disposed at least in the vicinity of the solid-state image pickup device, and has a mounting positioning marker on the optical element.

(Second configuration)
The solid-state imaging device according to the first configuration, wherein at least a part of the marker exists outside the effective area of the solid-state imaging element and within the effective area of the optical element.

(Third configuration)
At least one portion of the marker is disposed on the solid-state imaging device and the structure holding the frame holding the imaging lens is present within a projection area of the frame holding unit with respect to the solid-state imaging device. The solid-state imaging device according to any one of the first and second configurations.

(Fourth configuration)
The solid-state imaging device according to any one of the first to third configurations, wherein the marker is a fine structure formed on a surface of an optical element.

(Fifth configuration)
The solid-state imaging device according to any one of the first to fourth configurations, wherein the fine structure is concave or convex.

(Sixth configuration)
The solid-state imaging device according to any one of the first to fifth configurations, wherein the marker is arranged symmetrically and / or concentrically with respect to the optical axis of the optical element.

(Seventh configuration)
The solid-state imaging device according to any one of the first to sixth configurations, wherein a difference in transmittance between the marker and a portion other than the marker is 4% or more.

(Eighth configuration)
The solid-state imaging device according to the seventh configuration, wherein an antireflection treatment is applied to a region other than the marker of the optical element.

(Ninth configuration)
The seventh and eighth configurations are characterized in that the shape of the cross section of the fine structure portion in a direction intersecting the length direction of the fine structure is any one of a semicircular shape, a triangular shape, and a trapezoidal shape. Solid-state imaging device.

(Tenth configuration)
An imaging device comprising the solid-state imaging device according to any one of the first to ninth configurations.

(Eleventh configuration)
A transfer mold for forming the optical element, comprising: a basic transfer portion for forming the optical element; and a transfer groove for forming the marker.

(Twelfth configuration)
A transfer mold manufacturing method for manufacturing a transfer mold, comprising: a basic transfer part that molds the optical element; and a transfer groove that molds the marker, and forms a basic transfer part corresponding to the optical element. And a transfer groove forming step of forming a transfer groove corresponding to the marker by patterning a surface of the basic transfer portion.

(13th configuration)
A method for manufacturing a solid-state imaging device according to any one of the first to ninth configurations, comprising a molding step for forming at least the optical element and the marker. .

(14th configuration)
The step of forming the optical element and the marker includes a process of filling the mold with a fluid curable resin having fluidity; and a process of curing the energy curable resin by applying light energy or thermal energy. A method for manufacturing a solid-state imaging device according to a thirteenth configuration.

(15th configuration)
The process of using a transparent mold as the transfer mold and curing the energy curable resin is performed while confirming the position where the optical element is to be formed through the transparent mold directly to the solid-state imaging device. 15. A method for manufacturing a solid-state imaging device according to any one of the thirteenth and fourteenth configurations.

(Sixteenth configuration)
14. The method of manufacturing a solid-state imaging device according to the thirteenth configuration, wherein the step of forming the optical element and the marker includes a process of cooling and hardening after filling the transfer mold with a heated thermoplastic resin.

(17th configuration)
The step of fixing the optical element having the marker to the solid-state imaging device includes applying the energy curable resin having fluidity on the optical element or the solid-state imaging device, and applying light or thermal energy to the energy curable resin. The method for manufacturing a solid-state imaging device according to any one of the thirteenth and sixteenth configurations, including a curing process.

(18th configuration)
18. The process according to any one of the thirteenth, sixteenth, and seventeenth aspects, wherein the process of curing the energy curable resin is performed while confirming a position where the optical element is to be disposed through an optical element having a marker. Manufacturing method of solid-state imaging device.

(19th configuration)
A method for manufacturing an imaging device according to a tenth configuration, wherein a fixing process of a lens holder for mounting an imaging lens is performed on the solid-state imaging device according to any one of the first to ninth configurations, A method for manufacturing an imaging device, wherein the method is performed while confirming the marker position through a lens holder.

(20th configuration)
A method for manufacturing an imaging device according to a tenth configuration, wherein a fixing process of a lens holder for mounting an imaging lens is performed on the solid-state imaging device according to any one of the first to ninth configurations, The method of manufacturing an imaging device according to the nineteenth configuration, wherein the marker position is confirmed as a differential interference image through a lens holder.

  The solid-state imaging unit according to the present invention can be suitably used in, for example, a digital camera and a digital video camera.

2A and 2B are diagrams illustrating a configuration of the imaging apparatus according to the first embodiment, in which FIG. 1A is a cross-sectional view of the imaging apparatus in a state where an imaging lens unit is removed, and FIG. 2B is a diagram illustrating the imaging apparatus illustrated in FIG. It is a top view of an imaging unit when it sees from. In the imaging device of Embodiment 1, it is sectional drawing which shows the state which attached the imaging lens unit. It is sectional drawing which shows the structure of the imaging device which provided the marker in the transparent plate. It is sectional drawing which shows the cross section of a marker typically. It is the figure which showed the imaging unit at the time of making a marker black, (a) is sectional drawing of an imaging unit, (b) is a top view of an imaging unit. It is sectional drawing which shows the structure of the optical element in which the reflection preventing layer was formed. It is sectional drawing which shows typically the shape of a transcription | transfer type | mold, (a) is a transcription | transfer type for forming a marker as a projection part, (b) is a transcription | transfer type for forming a marker as a groove | channel. It is a figure which shows the manufacturing method of the transfer type | mold which shape | molds a marker as a projection part, (a) is a figure which shows a mold raw material, (b) is the figure which formed the optical element transfer surface, (c) is (D) is a diagram in which a photosensitive resist portion is formed, (e) is a diagram in which the photosensitive resist portion is removed, (f) is a diagram in which a transfer groove is formed, (G) is the figure which removed the photoresist. It is a figure which shows the manufacturing method of the master type | mold used for formation of the transfer type | mold which shape | molds a marker as a groove | channel, (a) is a figure which shows a mold raw material, (b) is the figure which formed the optical element transfer surface. (C) is a view in which a photoresist is formed, (d) is a view in which a photosensitive resist portion is formed, (e) is a view in which the photosensitive resist portion is removed, and (f) is a view in which a marker forming portion is formed. It is the figure which formed, (g) is the figure which removed the photoresist. It is a figure which shows the manufacturing method which forms a transfer type | mold using the master type | mold formed by the manufacturing method shown to Fig.9 (a)-(g), (a) is the figure which set the preform with respect to the master type | mold. FIG. 6B is a diagram in which a preform is molded using a master mold, and FIG. 5C is a diagram in which the master mold is released. It is the figure which showed the method of shape | molding an optical element using the transfer type | mold which shape | molds a marker as a groove | channel, (a) is a figure of a filling process, (b) aligns a transfer type | mold and an effective pixel area | region. (C) is a figure of a hardening process, (d) is the figure which released the transfer type | mold. It is a figure which shows the method of manufacturing an optical element using the transcription | transfer type | mold which shape | molds a marker as a projection part, (a) is the figure which opened the die set, (b) is the die-clamping, resin (C) is a view in which the optical element is released, (d) is a view in which an antireflection layer is formed on the resin-molded optical element, and (e) is a molded optical element. It is a figure which shows an element. It is the figure which showed the method of fixing an optical element to an imaging unit, (a) is a figure which apply | coats the adhesive resin which adhere | attaches an optical element and a transparent board, (b) is the center of an optical element, and an effective pixel It is a figure which aligns with the center of a field, and (c) is a figure which hardens adhesive resin. It is a figure which shows the attachment process which attaches a holding unit to an imaging unit, (a) is a figure which images the lens holder of a holding unit, and the optical element of an imaging unit, (b) is a figure which aligns a holding unit. (C) is the figure which attached the holding | maintenance unit to the imaging unit. It is a figure which attaches an imaging lens unit to a holding unit. It is a figure which shows the structure of the conventional imaging device, (a) is a top view, (b) is sectional drawing. It is sectional drawing which shows the path | route of the light which injects into an image pick-up element. It is sectional drawing which shows the structure of the conventional imaging device. It is sectional drawing which shows the structure of the conventional imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging device 10 Imaging unit 11 Sensor chip (imaging element)
DESCRIPTION OF SYMBOLS 12 Effective pixel area 13 Sensor board 14 Transparent board 15 Unit case 16 Bonding wire 17 External connection terminal 18 Optical element 18a Marker (positioning means)
18b Effective area 20 Holding unit 21 Lens holder 21a Focus adjusting screw part 21b Inner diameter of focus adjusting screw part 22 Yoke 23 Magnet 24 Coil 25 Actuator housing 26 Opening part 27 AF mechanism 30 Imaging lens unit 31 Imaging lens system 32 Imaging lens System barrel 40, 50 Transfer mold 40a Transfer groove (positioning means transfer section)
50a Transfer protrusion (positioning means transfer portion)
40b Optical element transfer surface (optical element transfer part)
50b Optical element transfer surface (optical element transfer part)

Claims (23)

An image pickup having a lens holder having an opening for holding an image pickup lens system, an image pickup element for converting light passing through the image pickup lens system into an electric signal, and positioning means for determining a position of the lens holder with respect to the image pickup element In the device
The opening of the lens holder is designed so that the lens holder covers a part of the effective pixel area of the imaging device,
The imaging apparatus, wherein the positioning means is a position where at least a part of the positioning means can be visually recognized through the opening of the lens holder, and is provided outside the effective pixel region. An optical element that corrects light that has passed through the imaging lens system is further provided between the imaging element and the imaging lens system,
The imaging apparatus according to claim 1, wherein the positioning unit is provided in the optical element.   The imaging apparatus according to claim 2, wherein the positioning unit is provided in an effective area of the optical element.   The imaging apparatus according to claim 1, wherein the positioning unit is provided in a projection plane when the lens holder is projected onto the imaging element.   The imaging apparatus according to claim 1, wherein the positioning unit is a protrusion or a groove.   6. The imaging apparatus according to claim 5, wherein the positioning means has a hemispherical shape, a cone shape, or a frustum shape.   The image pickup apparatus according to claim 1, wherein a plurality of the positioning means are provided.   8. The imaging apparatus according to claim 7, wherein the positioning unit is provided at a position that equally divides a circumference of a circle having the optical axis of the imaging lens system as a center.   3. The optical element according to claim 2, wherein a difference between a transmittance of a region where the positioning unit is formed and a transmittance of a region where the positioning unit is not formed is 4% or more. The imaging device according to any one of 8.   10. The imaging unit according to claim 2, wherein an antireflection layer is provided in a region excluding the region where the positioning unit is formed in the optical element. 11. A method for manufacturing an imaging apparatus, comprising: a lens holder having an opening that holds an imaging lens system; an imaging element that converts light that has passed through the imaging lens system into an electrical signal; and positioning means that determines a position of the lens holder. In
A lens holder forming step for forming the lens holder in which the opening is designed so as to cover a part of the effective pixel region of the imaging element;
A positioning means forming step for forming at least a part of the positioning means outside the effective pixel area of the imaging element and at a position where the positioning means is visible through the opening of the lens holder. Production method. The positioning means forming step includes
A filling step of filling the transfer mold with a resin having fluidity;
The method for manufacturing an imaging device according to claim 11, further comprising: a curing step of curing the resin filled in the transfer mold.   The positioning means forming step is characterized in that the positioning means is formed on an optical element that is provided between the imaging element and the imaging lens system and corrects light that has passed through the imaging lens system. A method for manufacturing the imaging device according to 11 or 12.   13. The method of manufacturing an imaging apparatus according to claim 12, wherein in the positioning means forming step, the optical element and the positioning means are simultaneously molded.   15. The imaging according to any one of claims 12 to 14, wherein the transfer mold includes an optical element transfer unit that molds the optical element and a positioning unit transfer unit that molds the positioning unit. Device manufacturing method.   The method of manufacturing an imaging apparatus according to claim 15, wherein the transfer mold is made of a material that transmits light.   17. The method of manufacturing an image pickup apparatus according to claim 15, wherein the positioning unit transfer portion is formed by patterning a surface of the optical element transfer portion.   The method for manufacturing an imaging device according to claim 12, wherein the resin is an energy curable resin that is cured by at least one of light energy and thermal energy.   18. The method for manufacturing an imaging device according to claim 12, wherein the resin is a thermoplastic resin. A fixing step of fixing the optical element including the positioning unit to an imaging unit including the imaging element;
13. The fixing step includes applying a resin made of a material that transmits light after curing to a surface of the optical element or the imaging unit on which the optical element is fixed, and then curing the resin. 20. A method for manufacturing an imaging device according to any one of 19 above.   21. The method of manufacturing an imaging apparatus according to claim 20, wherein, in the fixing step, the resin is cured while visually confirming the positioning means through the lens holder.   12. An attachment step of attaching the lens holder formed in the lens holder formation step to an image pickup unit including the image pickup device while visually recognizing the attachment means through the opening of the lens holder. The manufacturing method of the imaging device of any one of 21.   23. The method of manufacturing an imaging apparatus according to claim 22, wherein in the attaching step, the positioning unit is confirmed as a differential interference image.

Images