JP2008250285A - Optical member and imaging device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical member for preventing resin from entering an infrared wavelength cut film when a lens is formed, and suppressing separation of the lens caused by a difference in linear expansion due to fixation of the lens made of a resin to the infrared wavelength cut filter made of glass and preventing dust originated from the infrared wavelength cut film from falling onto an imaging device, and to provide an imaging device including the same. <P>SOLUTION: The infrared wavelength cut film 3 is formed on a light-transmitting substrate 1, and the lens 2 having a first flat surface 2a on the infrared wavelength cut film 3 is provided on the infrared wavelength cut film 3. The lens 2 is fixed to a light-transmitting substrate 1 outside a lens effective diameter R. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical member including an infrared wavelength cut film and a focusing lens used in a digital camera, a video camera, and the like, and an imaging device including the optical member.

  CCD (Charge Coupled Device) elements and CMOS (Complementary Metal Oxide Semiconductor) elements are often used as imaging elements for video cameras, digital cameras, and the like. These image sensors have sensitivity to light in a relatively wide wavelength range, and have good sensitivity not only to the visible light region but also to light in the near infrared region (750 to 2500 nm). However, in ordinary camera applications, light in the infrared region that is invisible to the human eye is not necessary, and near-infrared light that enters the image sensor may cause inconveniences such as reduced resolution and image unevenness. become. For this reason, an infrared cut filter such as colored glass is inserted in the optical system of the camera to cut near infrared light in the incident light.

  In recent years, there has been a growing demand for miniaturization and weight reduction in video cameras, digital cameras, especially camera modules mounted on mobile phones. In order to achieve miniaturization, there is a method of reducing the thickness of the entire optical system in the optical axis direction by shortening the focal length of the lens. However, when the distance from the lens to the image sensor becomes small due to the thinning of the entire optical system in the optical axis direction, the incident angle increases when the light beam passes through the periphery of the optical axis and enters the image sensor. End up.

  When the incident angle increases, the following two problems arise.

  The first problem is due to the incident angle dependence of the infrared wavelength cut filter. In other words, due to the incident angle dependence, light in the infrared wavelength region is sufficiently cut off at the center of the optical axis where the incident angle is small, but incident on the image sensor as the light beam goes from the center to the periphery of the optical axis. The angle increases, and as a result, light in the infrared wavelength region is not cut, and light in the red wavelength is cut. For this reason, an image obtained by converting the image sensor into an electrical signal has a tendency to become bluish as it goes from the center to the periphery. As a result, the larger the incident angle, the shorter the wavelength of light cut by the infrared wavelength cut filter, which causes screen color unevenness.

  The second problem is that the amount of light around the optical axis is less than the central part of the optical axis. That is, an image converted from an image sensor to an electrical signal tends to become darker as it goes from the central part to the peripheral part.

  For example, in Patent Document 1, an infrared wavelength cut film that is an infrared wavelength cut filter is provided on one flat surface of a plate-like light-transmitting substrate, and a resin focusing lens is directly placed on the infrared wavelength cut film. It is disclosed to form. Specifically, as shown in FIG. 15, an infrared wavelength cut film 103 is provided on a light transmissive substrate 101, and a lens 102 made of resin is further formed thereon. Although not shown, a light beam incident from the upper side of the drawing is refracted by the lens 102 and enters the infrared wavelength cut film 103. The incident light beam is cut by the infrared wavelength cut film 103 in the infrared wavelength region. Thereafter, the light beam passes through the light-transmitting substrate 101 and finally forms an image on the image sensor 107.

  When a light beam passing through the optical axis of the optical system enters the image sensor 107 through the center of the lens 102, the incident angle with respect to the infrared wavelength cut film 103 is 0 °. On the other hand, the light beam incident on the end of the image sensor 107 is refracted by the lens 102 so as to be focused toward the optical axis, and enters the infrared wavelength cut film 103 at an incident angle smaller than the incident angle without the lens 102. Then, the light passing through the infrared wavelength cut film 103 enters the image sensor 107. Thus, the lens 102 functions as a lens that reduces the incident angle.

In another conventional example, there is an imaging device shown in FIG. The difference from the above-mentioned Patent Document 1 is that the infrared wavelength cut film 203 is disposed on the package 207 side, and the lens 202 and the light transmitting substrate 201 are directly bonded. The lens 202 is an aspherical surface (not shown in the figure), and has an effect of reducing the incident angle around the optical axis. A technique is disclosed in which the lens 202 reduces the angle dependency of the infrared wavelength cut film and suppresses color unevenness in the image.
Japanese Patent Laying-Open No. 2005-234038 (published on September 2, 2005)

  However, the conventional technology has several problems described below.

  First, in the conventional structure shown in FIG. 15, the raw material of the lens 102 is made of a liquid resin, and a fixed lens is produced by curing the resin with ultraviolet rays or heat. Here, if the resin is cured on the infrared wavelength cut film 103, the resin enters the minute cracks of the infrared wavelength cut film 103, and the characteristics of the infrared wavelength cut film 103 deteriorate. In addition, volume shrinkage occurs when the resin is cured. For this reason, if the resin is cured while in contact with the infrared wavelength cut film 103 made of glass, the cured resin may be peeled off from the infrared wavelength cut film 103 made of glass.

  For this reason, it is necessary to harden the resin at a place different from that on the infrared wavelength cut film 103. In this case, the lens 102 produced by curing the resin is pasted on the infrared wavelength cut film 103. However, if the lens 102 is pasted over the entire plane of the lens 102, the lens 102 is easily peeled due to the difference in volume expansion coefficient. That is, since the linear expansion coefficient between the infrared wavelength cut film 103 and the resin is generally different by one digit or more, the temperature change causes the peeling of the lens 102 and the crack of the infrared wavelength cut film 103.

  Further, when the lens 102 is affixed on the infrared wavelength cut film 103, the adhesive is provided in the region through which the light passes, so that the demand for optical characteristics of the adhesive becomes severe, There is a possibility that sufficient adhesive force cannot be obtained due to the balance.

  On the other hand, in the configuration shown in FIG. 16 of the conventional example, the solid-state imaging device 206 is provided on the side where the infrared wavelength cut film 203 is formed. In this configuration, minute debris and dust that come out of the infrared wavelength cut film 203 fall on the solid-state image sensor 206, and a blot of an image converted into an electrical signal is generated.

  The present invention has been made in view of the above-described problems, and its purpose is to prevent the penetration of the resin into the infrared wavelength cut film during the formation of the lens, and the infrared comprising the resin lens and the glass. Optical member capable of suppressing peeling of lens due to difference in linear expansion due to fixation with wavelength cut filter, and preventing dust coming out of infrared wavelength cut film from falling on image pickup device, and image pickup device including the same Is to provide.

  In order to solve the above-described problems, the optical member of the present invention is provided with an infrared wavelength cut film on a light-transmitting substrate, and a lens having a first flat surface on the infrared wavelength cut film side above the infrared wavelength cut film. Is provided, and the lens is fixed to the light-transmitting substrate at an outer peripheral portion with respect to an effective diameter of the lens.

  According to the above configuration, since the infrared wavelength cut film is provided, it is possible to cut infrared wavelengths and remove inconveniences such as a decrease in resolution and image unevenness.

  Further, the lens is fixed to the light-transmitting substrate at the outer peripheral portion than the lens effective diameter. As a result, the lens is not fixed to the infrared wavelength cut film made of glass within the lens effective diameter. Therefore, when the lens made of resin is directly formed on the infrared wavelength cut film made of glass, or when the lens made of resin is attached to the infrared wavelength cut film made of glass, the lens and the infrared wavelength cut generated. Peeling due to the difference in linear expansion from the film can be suppressed. Further, since the lens and the light-transmitting substrate are not bonded on the entire surface but are fixed on the outer periphery of the lens, there is no influence due to the difference in linear expansion. Furthermore, when pasted within the lens effective diameter, the adhesive was limited to one having optical transparency, but the use of an adhesive that does not require optical properties because it is fixed at the outer periphery than the lens effective diameter. Therefore, it is possible to preferentially use a material having a large adhesive strength.

  Further, as in Patent Document 1 shown in FIG. 15, when the lens 102 made of resin is directly formed on the light-transmitting substrate 101, it is difficult to align the solid-state imaging device 106 and the lens 102. Then, it is easy to perform alignment while confirming the solid-state imaging device from the lens.

  Moreover, in the structure of this invention, it can be said that hardening of resin is not performed on an infrared wavelength cut film. This is because if the resin is cured on the infrared wavelength cut film, the infrared wavelength cut film made of glass and the lens are necessarily fixed within the effective lens diameter. That is, in the present invention, a lens formed in advance is used.

  Therefore, since the resin is not cured on the infrared wavelength cut film, damage to the infrared wavelength cut film due to the penetration of the resin into the infrared wavelength cut film is suppressed, and the characteristics of the infrared wavelength cut film are deteriorated. Can be suppressed.

  Furthermore, in the configuration of the present invention, since the infrared wavelength cut film is provided on the light transmissive substrate, dust from the infrared wavelength cut film may fall on the image sensor provided on the lower side of the light transmissive substrate. Absent.

  Therefore, it prevents the resin from penetrating into the infrared wavelength cut film when forming the lens, and prevents the lens from peeling off due to the difference in linear expansion between the resin lens and the glass infrared wavelength cut filter. It is possible to provide an optical member that can suppress and prevent the dust from the infrared wavelength cut film from falling on the image sensor.

  In the optical member of the present invention, the light transmissive substrate has a second flat surface on the lens side, while the infrared wavelength cut film is provided on the second flat surface of the light transmissive substrate. It is preferable that

  Thereby, by forming the infrared wavelength cut film on the second flat surface of the light transmissive substrate, manufacturing is easier than forming the infrared wavelength cut film on the three-dimensional surface of the light transmissive substrate. Thus, it is possible to provide a lower cost and higher performance optical member.

  In the optical member of the present invention, it is preferable that a first antireflection film is provided between the lens and the infrared wavelength cut film.

  That is, it is conceivable to use an adhesive, for example, in order to fix the lens to the light transmissive substrate at the outer peripheral portion than the lens effective diameter. In this case, an air layer is inevitably formed between the lens and the infrared wavelength cut film, and as a result, reflection based on a difference in refractive index occurs between the lens and the infrared wavelength cut film.

  In this regard, in the present invention, since the first antireflection film is provided between the lens and the infrared wavelength cut film, the reflected light from the lens surface can be removed, and the amount of light sufficient for imaging. It is possible to provide a high-performance optical member capable of obtaining the above.

  In the optical member of the present invention, it is preferable that the first antireflection film is provided on the first flat surface of the lens.

  Thus, by providing the first antireflection film on the first flat surface of the lens, various film formation methods such as vapor deposition, sputtering, and spin coating can be selected as appropriate to obtain a high-quality antireflection film. Can be used.

  In the optical member of the present invention, it is preferable that the first antireflection film is opposed to the infrared wavelength cut film through an air layer.

  As a result, the first antireflection film and the infrared wavelength cut film are not in direct contact with each other. As a result, scratches and deterioration of quality due to mutual contact can be prevented, so that a high-quality optical member can be provided.

  In the optical member of the present invention, the air layer is sealed with the infrared wavelength cut film, the first antireflection film, and an adhesive that bonds the infrared wavelength cut film and the lens. It is preferable that

  Thereby, the intrusion of water derived from moisture in the atmosphere can be prevented, and dew exposure to the lens can be suppressed, so that an optical member having environmental resistance can be provided. It is also possible to prevent dust and the like from adhering to the infrared wavelength cut film or the first antireflection film due to dust and the like in the atmosphere being mixed into the air layer.

  In the optical member of the present invention, the outer peripheral portion of the lens has an effective diameter that protrudes toward the infrared wavelength cut film, and between the infrared wavelength cut film and the first antireflection film. The outer peripheral projection part which provides an air layer may be formed so that it may contact | abut to this infrared wavelength cut film.

  That is, the outer peripheral protrusion is a part of the lens, and the height of the protrusion can be precisely controlled. For this reason, since the thickness can be controlled more easily than using a fixing material such as an adhesive, an inclination occurs between the first flat surface of the lens and the second flat surface of the light-transmitting substrate. This makes it difficult to maintain parallelism between the lens and the light transmissive substrate. Therefore, it becomes difficult for the optical axis to be displaced, so that the reliability of the optical system can be improved.

  In the optical member of the present invention, the air layer includes the infrared wavelength cut film, the first antireflection film, the outer peripheral protrusion, the outer peripheral protrusion, and the first antireflection film. It is preferable to be sealed with an adhesive that fixes the substrate.

  Thereby, the intrusion of water derived from moisture in the atmosphere can be prevented, and dew exposure to the lens can be suppressed, so that an optical member having environmental resistance can be provided. It is also possible to prevent dust and the like from adhering to the infrared wavelength cut film or the first antireflection film due to dust and the like in the atmosphere being mixed into the air layer.

  In the present invention, the lens is provided with an outer peripheral projection to reduce the bonding area between the infrared wavelength cut film and the lens. For this reason, it is possible to prevent peeling due to the difference in linear expansion between the lens made of resin and the infrared wavelength cut film made of glass.

  In this configuration, for example, the lens and the infrared wavelength cut film are sealed with a sealing resin outside the outer peripheral projection. Therefore, since the sealing resin and the infrared wavelength cut film do not come into contact with each other within the effective diameter of the lens, the damage to the infrared wavelength cut film caused by the seal resin due to scratches and erosion is suppressed, and a highly durable optical member is formed. Can be provided.

  In the optical member of the present invention, it is preferable that the lens is formed so that a cross section of a side surface opposite to the surface facing the light-transmitting substrate has an aspherical shape.

  Thereby, the incident angle of the light beam around the optical axis can be reduced, and the angle dependency of the infrared wavelength cut film can be suppressed. As a result, it is possible to suppress color unevenness in the obtained image. In addition, the aspherical shape of the lens can reduce the difference in the amount of light between the center of the lens and the periphery of the lens, and can also correct aberrations such as distortion. Can be provided.

  In the optical member of the present invention, the lens has an aspherical shape in which the cross section of the side surface opposite to the surface facing the light-transmitting substrate has a maximum thickness between the center of the optical axis and the outer periphery of the effective diameter of the lens. It is preferable that it is formed so that.

  In the optical member of the present invention, the lens has a cross section on the side opposite to the surface facing the light transmissive substrate having a maximum value at the center of the optical axis, and the outer periphery of the lens effective diameter and the lens outermost. It is preferable to form an aspheric shape having a minimum thickness between the outer periphery and the outer periphery.

  With the specific configuration of these lenses, the incident angle of the light beam around the optical axis can be reliably reduced, and the angle dependency of the infrared wavelength cut film can be suppressed.

  In the optical member of the present invention, a second antireflection film may be formed on the lens on the side surface opposite to the surface facing the light transmissive substrate.

  Thereby, reflection based on the difference in refractive index between the air layer outside the lens and the lens can be prevented.

  In the optical member according to the aspect of the invention, it is preferable that a plurality of the lenses are manufactured in a single-row sheet shape.

  In the optical member of the present invention, it is preferable that a plurality of the lenses are manufactured in an array.

  In this way, a large number of lenses can be manufactured at a time by manufacturing the lenses in a single row of sheets or arrays. As a result, the manufacturing time can be shortened and the manufacturing cost can be reduced, and an inexpensive optical member can be provided quickly.

  In the optical member of the present invention, it is preferable that the manufactured one row of sheet-like lenses are separated from each other after being provided on the light-transmitting substrate.

  In the optical member of the present invention, it is preferable that the manufactured array-shaped lenses are individually separated after being provided on the light-transmitting substrate.

  Thus, the cutting process can be reduced by cutting the sheet-shaped or array-shaped lens and the light-transmitting substrate together. Further, it can be produced without causing a deviation between the lens and the light-transmitting substrate, and an inexpensive and high-quality optical member can be provided.

  Moreover, in order to solve the said subject, the imaging device of this invention is an imaging device provided with the above-mentioned optical member, Comprising: On the opposite side to the said lens of the said light transmissive board | substrate in the said optical member A package having an opening on the light-transmitting substrate side; and a solid-state imaging device fixed to the package, the solid-state imaging device being covered in the package, and the opening being closed. And a light-transmitting dust-proof cover.

  According to said structure, the optical member is provided on the package which has a light-transmissive dustproof cover which covers a solid-state image sensor and obstruct | occludes an opening part.

  Therefore, the penetration of the resin into the infrared wavelength cut film during lens formation is prevented, and the peeling of the lens due to the difference in linear expansion due to the fixation between the resin lens and the glass infrared wavelength cut filter is suppressed. And the imaging device provided with the optical member which can avoid that the dust which comes out of an infrared wavelength cut film falls on an image sensor can be provided.

  In order to solve the above-described problems, the optical member of the present invention is provided with an infrared wavelength cut film on a light-transmitting substrate, and a lens having a third flat surface on the infrared wavelength cut film side above the optical wavelength cut film. And a resin is provided so as to be in contact with the side wall of the light-transmitting substrate, and the lens is fixed to the resin at the outer peripheral portion rather than the effective lens diameter.

  According to the above invention, the lens is not fixed to the infrared wavelength cut film made of, for example, glass within the lens effective diameter. Therefore, for example, when a lens made of resin is directly formed on an infrared wavelength cut film made of glass, for example, or when a lens made of resin is stuck on an infrared wavelength cut film made of glass, for example, Peeling due to the difference in linear expansion from the infrared wavelength cut film can be suppressed (peeling does not occur).

  Moreover, according to said structure, a lens is adhere | attached with resin outside a lens effective diameter. Therefore, comparing the case where the infrared wavelength cut film and the lens are bonded, the problem that the lens is simultaneously peeled from the light transmissive substrate by peeling the infrared wavelength cut film from the light transmissive substrate is solved. Can do.

  In the optical member of the present invention, the light transmissive substrate has a fourth flat surface on the lens side, while the infrared wavelength cut film is provided on the fourth flat surface of the light transmissive substrate. It is preferable that

  Thereby, by forming the infrared wavelength cut film on the fourth flat surface of the light transmissive substrate, manufacture is easier than forming the infrared wavelength cut film on the three-dimensional surface of the light transmissive substrate. Thus, it is possible to provide a lower cost and higher performance optical member.

  In the optical member of the present invention, the planar shape of the lens as viewed from the optical axis direction of the lens includes the planar shape of the entire light transmissive substrate and the planar shape of a part of the resin. It is preferable.

  In the optical member of the present invention, the planar shape of the lens as viewed from the optical axis direction of the lens includes a partial planar shape of the light-transmitting substrate and a partial planar shape of the resin. It is preferable that

  As a result, the lens is completely or substantially formed on the light-transmitting substrate, and the light can be refracted by its optical performance and guided to the solid-state imaging device through the light-transmitting substrate. In addition, it is possible to make a bonding location where the lens and the resin can be bonded except on the light transmissive substrate. As a result, the adhesive force of the lens can be increased as compared with the case of bonding to the light transmissive substrate, and a more reliable optical member can be provided.

  In the optical member of the present invention, the resin has a fifth flat surface parallel to the fourth flat surface of the light-transmitting substrate on the lens side, and the lens is made of the resin. It is preferable to be fixed to the fifth flat surface with an adhesive.

  Thus, the resin can be molded with the fourth flat surface of the light-transmitting substrate as a reference, and the fifth flat surface of the resin can be used as a reference for the optical system. Furthermore, by attaching the lens to the fifth flat surface, it is possible to perform adjustment with a small inclination with respect to the lens, and to improve the reliability of the optical system.

  In the optical member of the present invention, the fifth flat surface of the resin is present on the same plane as the fourth flat surface of the light transmissive substrate, or the lens is more than the fourth flat surface. It is preferable that it does not protrude to the side.

  In this configuration, the resin surrounds the light transmissive substrate. As a result, the light-transmitting substrate is positioned within the lens effective diameter, while the resin is positioned outside the lens effective diameter. Therefore, by bonding the lens and the resin outside the effective lens diameter, it is possible to provide an optical member that suppresses peeling of the light transmissive substrate with respect to the lens.

  In the optical member of the present invention, it is preferable that the fourth flat surface of the light-transmitting substrate is disposed closer to the third flat surface side of the lens than the fifth flat surface of the resin. .

  In this configuration, the fifth flat surface of the resin is lowered by one step from the fourth flat surface of the light transmissive substrate. Thereby, when the periphery of the light transmissive substrate is filled with resin, the problem that the resin wraps around the surface of the fourth flat surface of the light transmissive substrate can be solved.

  In the optical member of the present invention, the outer peripheral portion of the lens protrudes toward the fifth flat surface side of the effective diameter, and the third flat surface of the lens and the light transmissive substrate It is preferable that an outer peripheral protrusion portion that provides an air layer between the flat surface and the flat surface of 4 is formed so as to contact the fifth flat surface.

  That is, the outer peripheral protrusion is a part of the lens, and the height of the outer peripheral protrusion can be precisely controlled. For this reason, it becomes easier to control the thickness than using a fixing agent such as an adhesive, so that it is difficult to cause an inclination between the third flat surface of the lens and the fifth flat surface of the resin, Parallelism between the lens and the light transmissive substrate can be maintained. Therefore, since the optical axis is hardly displaced, the reliability of the optical system can be improved.

  Furthermore, since the air layer is provided, the lens and the light-transmitting substrate are not in direct contact with each other, and peeling of the light-transmitting substrate from the lens due to a difference in linear expansion and damage to the infrared cut film by the resin can be suppressed. .

  In the optical member of the present invention, it is preferable that a third antireflection film is provided on the third flat surface of the lens.

  Thereby, the Fresnel reflection by the difference in the refractive index of a lens and an air layer can be suppressed, and the flare light observed as an imaging system as a result can be suppressed.

  In the optical member of the present invention, the air layer is provided on the third antireflection film provided on the third flat surface of the lens, the outer peripheral protrusion, and the light transmissive substrate. It is preferable that sealing is performed by the infrared wavelength cut film and the fifth flat surface of the resin.

  Thereby, the intrusion of water derived from moisture in the atmosphere can be prevented, and dew exposure to the lens can be suppressed, so that an optical member having environmental resistance can be provided.

  Moreover, in order to solve the said subject, the imaging device of this invention is an imaging device provided with the above-mentioned optical member, Comprising: On the opposite side to the said lens of the said light transmissive board | substrate in the said optical member The solid-state imaging device is provided, and the solid-state imaging device is sealed with the resin.

  According to the above invention, an imaging device in which a lens is directly formed can be formed, and a thin and small imaging device can be provided.

  As described above, the optical member of the present invention is provided with an infrared wavelength cut film made of glass on a light-transmitting substrate made of an inorganic material, further provided with a lens made of resin, and The lens is fixed to the light-transmitting substrate at the outer peripheral portion than the lens effective diameter.

  In addition, as described above, the imaging device of the present invention is provided with the infrared wavelength cut film on the light-transmitting substrate, and on the upper side thereof, the lens having the third flat surface on the infrared wavelength cut film side. A resin is provided so as to be in contact with the side wall of the light-transmitting substrate, and the lens is fixed to the resin at the outer peripheral portion rather than the lens effective diameter.

  In addition, as described above, the imaging device of the present invention is an imaging device including the optical member described above, and the light transmitting substrate in the optical member has the light on the side opposite to the lens. A package having an opening on the transmissive substrate side is provided, and in the package, a solid-state imaging device fixed to the package, and a light transmission covering the solid-state imaging device and closing the opening A dustproof cover is provided.

  Moreover, as described above, the imaging device of the present invention is an imaging device including the optical member described above, and a solid-state imaging is provided on the side of the optical member opposite to the lens of the light transmissive substrate. An element is provided, and the solid-state imaging element is sealed with the resin.

  Therefore, it prevents the resin from penetrating into the infrared wavelength cut film when forming the lens, and prevents the lens from peeling off due to the difference in linear expansion between the resin lens and the glass infrared wavelength cut filter. There is an effect that it is possible to provide an optical member that can be suppressed and that dust from the infrared wavelength cut film can be prevented from falling on the image pickup device, and an image pickup device including the optical member.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to FIGS.

  First, the structure of the optical member 10 of this Embodiment is demonstrated based on FIG. FIG. 1 is a cross-sectional view showing the optical member 10.

  As shown in the figure, the optical member 10 includes a light-transmitting substrate 1, a polymer resin lens 2, an infrared wavelength cut film 3, an antireflection film 4, and a seal resin 8 as an adhesive. I have.

The light transmissive substrate 1 is formed in a plate shape made of an inorganic material such as glass, and has two flat surfaces 1a and 1b. An infrared wavelength cut film 3 is formed on the flat surface 1 a as the second flat surface on the lens 2 side in the light transmissive substrate 1. Infrared wavelength cut film 3 is composed of a dielectric multilayer film such as SiO ₂ or MgF _2, it is formed by general film formation by vapor deposition method. This infrared wavelength cut film 3 is a low-pass filter, and can selectively extract only the infrared wavelength in the incident light by using the light interference effect.

  In addition, the film formation method of the infrared wavelength cut film 3 is not limited to the film formation method described above, and for example, a sputtering method, a spin coating method, or the like can be used.

  The lens 2 is formed by using a liquid polymer resin as a raw material and curing the liquid polymer resin with ultraviolet rays (UV) or heat. The surface of the lens 2 is formed in an aspheric shape. Thus, by forming the surface of the lens 2 in an aspherical shape, the incident angle of incident light can be reduced at the outer peripheral portion of the lens 2 as will be described in detail later. In the present embodiment, a polymer resin is used as a raw material for the lens 2, but the present invention is not limited to this, and a glass-molded one may be used as long as the lens 2 has a simple shape. . If the lens 2 made of glass is used, it is not necessary to consider the influence of deformation of the lens shape. Thereby, the lens 2 may be either organic or inorganic.

  The lens 2 has a flat surface 2a as a first flat surface on the side opposite to the aspheric surface side, that is, on the light-transmitting substrate 1, and the first antireflection film is formed on the flat surface 2a. The antireflection film 4 is formed by vapor deposition.

  The film formation method of the antireflection film 4 is not limited to the vapor deposition film formation method, and it is also possible to use a method such as a spin coating method or a sputtering method.

  In addition, a seal resin 8 is formed between the lens 2 and the infrared wavelength cut film 3 on the outer peripheral portion of the lens effective diameter R. With this configuration, the air layer 5 is formed on the inner peripheral side of the lens 2 with respect to the lens effective diameter R. Here, the lens effective diameter R described above does not indicate the outer diameter of the lens 2 but indicates the outermost peripheral portion of the region through which the light beam passes.

  The sealing resin 8 may be formed in a range slightly larger than the lens effective diameter R in consideration of mounting accuracy and the like. As a result, the light transmitted through the lens 2 is not affected.

  With the above configuration, incident light passes through the lens 2, the antireflection film 4, and the air layer 5 in this order before reaching the infrared wavelength cut film 3. Here, assuming that the refractive index of the polymer resin is n1 and the refractive index of air is n0, generally, n1 >> n0, and the refractive index n1 of the lens 2 and the refractive index n0 of air are greatly different. As a result, incident light is reflected at the boundary between the lens 2 and the air layer 5, and light loss occurs due to a decrease in the amount of incident light. Therefore, in the present embodiment, by providing the antireflection film 4, the reflection of incident light is suppressed and the loss of light is reduced.

  That is, the antireflection film 4 suppresses reflection from the surface of the lens 2 by causing interference between light reflected on the surface of the thin film and light reflected through the thin film and reflected in the back in the visible light region. It can be done.

  In the present embodiment, the antireflection film 4 is provided as the first antireflection film on the flat surface 2a on the opposite side of the aspherical surface of the lens 2, but not limited to this. It is also possible to provide the antireflection film 4 on the aspherical side of the lens 2 as a second antireflection film.

  Thereby, reflection based on the difference in refractive index between the air layer outside the lens 2 and the lens 2 can be prevented.

  Next, the sealing resin 8 is made of, for example, a photocurable adhesive having adhesiveness to both the inorganic material and the organic material. In the present embodiment, the light transmissive substrate 1 made of glass is an inorganic material, and the lens 2 made of a polymer resin is an organic material. These two materials are bonded by the sealing resin 8. The adhesion is performed by irradiating with ultraviolet (UV) light. In the case where the lens 2 is made of glass, the seal resin 8 may be a photocurable adhesive having an adhesive property to an inorganic material.

  The seal resin 8 has a rectangular shape or a circular shape excluding the area of the lens effective diameter R, or has a rectangular shape, and is provided by attaching a plurality of sheets to the outer periphery of the lens effective diameter R.

  Here, an important point in the seal resin 8 is to keep the thickness uniform. If the thickness of the sealing resin 8 is not uniform, the flat surface of the light transmissive substrate 1 and the flat surface of the lens 2 are inclined. As a result, the optical axis of the optical system (not shown) is inclined, and the coma aberration due to the lens 2 is increased. Accordingly, by keeping the thickness uniform, the flat surface of the light-transmitting substrate 1 and the flat surface of the lens 2 can be kept parallel. The sealing resin 8 is not limited to the above-described photo-curable adhesive, and for example, a double-sided tape-like one in which an adhesive is formed on both sides of the sheet may be used.

  According to the configuration of the optical member 10 of the present embodiment, a minute gap due to the thickness of the seal resin 8 is generated between the lens 2 and the light-transmitting substrate 1 in the inner peripheral portion of the lens 2 having an effective lens diameter R. The air layer 5 that is the minute gap can prevent direct contact between the lens 2 and the inner peripheral portion of the lens effective diameter R of the light transmissive substrate 1.

  Here, moisture in the atmosphere flows into the air layer 5 and there is a risk of dew. Further, when dust or the like in the atmosphere is mixed into the air layer 5, there is a risk that the dust or the like adheres on the infrared wavelength cut film 3 or the antireflection film 4. For this reason, it is preferable that the sealing resin 8 bonding the lens 2 and the light transmissive substrate 1 be completely sealed.

  In the present embodiment, the lens 2 and the light transmissive substrate are not in direct contact with each other at the inner periphery of the lens effective diameter R due to the presence of the air layer 5. 1 is effective in preventing scratches caused by friction with 1 and preventing erosion of the resin to the infrared wavelength cut film 3. Here, the lens 2 is made of a polymer resin, and the light transmissive substrate 1 is made of an inorganic material such as glass. In the prior art, these two materials were bonded in a large area. The thermal expansion coefficients of these materials are generally different by an order of magnitude or more. Due to this difference, when the temperature changes, the larger the bonding area, the larger the expansion stress, and the easier the phenomenon of adhesive resin peeling or resin cracking occurs. In the present embodiment, the air layer 5 is provided by bonding at the outer peripheral portion of the lens effective diameter R of the lens 2. As a result, by reducing the adhesion area between the light transmissive substrate 1 and the lens 2, it is possible to solve the problems of peeling of the adhesive resin and resin cracking. Further, by using a soft seal resin 8, it is possible to cope with a deviation due to thermal expansion between the light-transmitting substrate 1 and the lens 2.

  Next, the configuration of the imaging device 20 of the present embodiment including the optical member 10 having the above configuration will be described with reference to FIG. FIG. 2 is a cross-sectional view illustrating a configuration of the imaging device 20 using the optical member 10 as a dustproof cover.

  The imaging device 20 is an image sensor that is used in a digital still camera, a digital video camera, or the like, and converts optical information of optical imaging into an electrical signal by using photoelectric conversion. The imaging device 20 includes a concave package 7 made of an insulating material such as ceramic or resin, and the package 7 includes an opening through which light collected in an optical system described later enters. A solid-state image sensor 6 such as a CCD or CMOS is fixed to the center of the bottom surface inside the package 7 with an adhesive. The solid-state imaging device 6 is electrically connected to an outer electrode by a bonding wire (not shown). Although not shown, the electrode passes through the package 7 and is connected to the outside.

  In the present embodiment, the optical member 10 is attached to the opening of the package 7 with the lens 2 disposed outside. As a result, the optical member 10 closes the opening as a dust-proof cover, the package 7 is sealed, and entry of dust and the like is prevented.

  Next, the surface shape of the lens 2 according to the present embodiment and the optical path thereof will be described in detail with reference to FIG. FIG. 3 is a diagram in which the lens 2 of the present embodiment is applied to an optical system. Here, in order to explain the lens 2 in detail, the relationship between the lens 2 and the solid-state imaging device 6 is emphasized.

  As shown in FIG. 3, first, the light beam that has passed through the aperture 21 passes through the first lens group 22 and the second lens group 23 and enters the optical member 10. The incident light beam is refracted by the lens 2 provided on the optical member 10, and then passes through the antireflection film 4, the air layer 5, the infrared wavelength cut film 3, and the light transmissive substrate 1 in this order. Finally, the light beam is imaged on the solid-state image sensor 6. Here, the light beam passing through the optical axis of the optical system passes through the center of the lens 2 and enters the infrared wavelength cut film 3 at an incident angle of 0 °, and then enters the solid-state imaging device 6. On the other hand, the light beam incident on the end of the solid-state imaging device 6 is refracted by the lens 2 so as to be focused toward the optical axis, and has an incident angle smaller than the incident angle when the lens 2 is not present, and the infrared wavelength cut film 3. The light that has passed through the infrared wavelength cut film 3 enters the solid-state imaging device 6.

  Here, as shown in FIG. 1, the lens 2 of the present embodiment has an aspherical outer surface. This aspherical shape has, for example, the maximum thickness between the optical axis center portion and the outer periphery of the lens effective diameter R in the inner peripheral portion of the lens effective diameter R, and the thickness of the optical axis central portion is the maximum thickness. Is smaller than

  In the aspherical lens 2, since the incident angle of incident light is small at the center of the optical axis, even if the lens 2 at the center of the optical axis has a concave shape, the incident red near the center of the optical axis. External light can be cut sufficiently. Further, by having the maximum thickness between the outer periphery of the lens effective diameter R and the center of the optical axis, the incident angle of incident light incident on the infrared wavelength cut film 3 in the outer peripheral portion of the lens effective diameter R can be set. Can be small.

  As a result, conventionally, since the incident angle to the lens is large, color unevenness due to the fact that the infrared light is not cut and the red light is cut occurs, but in the lens 2 of the present embodiment, Since the incident angle of the light to the infrared wavelength cut film 3 can be reduced, the performance of cutting the infrared light at the outer peripheral portion than the lens effective diameter R can be improved. As a result, it is possible to suppress the color unevenness caused by the red light being cut due to the incident angle at the outer peripheral portion being larger than the conventional lens effective diameter R, and to improve the optical performance. As a result, the optical characteristics of the imaging device 20 can be improved.

  Further, as described above, the lens 2 functions as a lens for reducing the incident angle, so that the incident angle can be prevented from increasing as it goes to the end side of the solid-state imaging device 6. As a result, the incident angle dependency of the infrared wavelength cut film 3 can be suppressed, the difference between the central color tone of the image converted by the solid-state imaging device 6 and the peripheral color tone of the image is reduced, and the color tone of the image is uniform. Can be

  Further, the lens 2 can not only reduce the incident angle with respect to the infrared wavelength cut film 3, but also can suppress a change in the amount of light that decreases as it goes to the end side of the solid-state imaging device 6. As a result, the difference in the amount of light between the center and the periphery of the image converted by the solid-state image sensor 6 can be reduced, the brightness of the image can be made uniform, and a high-performance, small-sized imaging device 20 can be provided. it can.

  In addition, since various aberrations can be favorably corrected by making the lens 2 aspherical, various aberrations such as distortion are suppressed, and a good image is obtained. Therefore, a high-performance imaging device 20 can be provided.

  In the present invention, the shape is not necessarily limited to the above-mentioned aspherical shape. For example, as shown in FIG. 4, a lens formed to have an aspherical shape having a maximum thickness at the center of the optical axis or a minimum thickness between the outer periphery of the lens effective diameter R and the outermost lens periphery. 2S is also possible. This also brings about the same effect, and also has the effect of securing the mechanical strength around the lens 2 to prevent the deformation of the lens 2 and securing the adhesion area.

  The optical system shown here is composed of three lenses 22, 23, 2, but the number of lenses may be appropriately determined as necessary. If the lens 2 having a plane shown in the present embodiment is used, the lens 2 can be disposed close to the surface of the solid-state imaging device 6, and the optical system has a larger number than the optical system having a normal number of lenses. The size and thickness can be reduced.

  Next, a method for manufacturing the lens 2 according to the present embodiment will be described with reference to FIGS. 5A and 5B are diagrams illustrating a method for manufacturing the lens 2, in which FIG. 5A is a plan view of the lens sheet 25, and FIG. 5B is a side view of the lens sheet 25. is there.

  As shown in FIGS. 5A and 5B, in the present embodiment, for example, a polymer resin that is a material of the lens 2 is molded into an arrayed lens sheet 25 by a stamper. The lens sheet 25 includes a plurality of lenses 2 and is formed in a planar shape. After molding, the lens sheet 25 is diced and divided into individual lenses 2. In the above description, a stamper is used as a method for molding a polymer resin into a sheet shape, but the present invention is not necessarily limited to this method, and a forming method using cutting, or a gray A formation method in which exposure is performed using a scale mask may be used.

  Next, individual lenses 2 are produced by dicing from the lens sheet 25 on which the lenses 2 are molded. Thereafter, the light-transmissive substrate 1 is bonded with the sealing resin 8.

  Here, the lens sheet 25 may not be diced immediately after being molded. A manufacturing method thereof will be described below with reference to FIGS. 6A and 6B are diagrams showing another method for manufacturing the lens 2. FIG. 6A is a plan view showing the lens sheet 26 and the light-transmitting substrate sheet 11, and FIG. FIG. 5 is a side view showing attachment of the lens sheet 26 and the light transmissive substrate sheet 11.

  As shown in FIGS. 6A and 6B, the polymer resin as the material of the lens 2 is molded into the lens sheet 26 by a stamper. Thereafter, the light transmissive substrate sheet 11 having the same size as the lens sheet 26 is placed below the lens sheet 26 without dicing the lens sheet 26 into individual lens sizes. That is, the light transmissive substrate sheet 11 is not diced to the lens size, but is bonded to the lens sheet 26, and the lens sheet 26 and the light transmissive substrate sheet 11 are diced together. Thereby, the integral thing of the lens 2 and the translucent board | substrate sheet | seat 11 is cut | disconnected separately.

  According to the above manufacturing method, the dicing process can be reduced by dicing the lens sheet 26 and the light-transmitting substrate sheet 11 together. In other words, a large number of lenses can be manufactured at one time by manufacturing the array. As a result, the manufacturing time can be shortened and the manufacturing cost can be reduced, and an inexpensive optical member can be provided quickly.

  In addition, since the arrayed lens 2 and the light transmissive substrate sheet 11 can be simultaneously cut as described above, the cutting process can be reduced, and the lens 2 and the light transmissive substrate sheet 11 can be further reduced. It can be manufactured without causing a shift, and an inexpensive and high-quality optical member can be provided.

  In the above description, the lens 2 is molded on the arrayed lens sheet 25, but the present invention is not limited to this. For example, as shown in FIGS. It is also possible to produce. 7A is a plan view showing the lens sheet row 27 and the light transmissive substrate sheet row 12, and FIG. 7B is a side view showing attachment of the lens sheet row 27 and the light transmissive substrate sheet row 12. FIG.

  As described above, a large number of lenses 2 can be manufactured at a time by manufacturing the lens sheet rows 27 in a single row. As a result, the manufacturing time can be shortened and the manufacturing cost can be reduced, and an inexpensive optical member can be provided quickly.

  In addition, according to the manufacturing method described above, since the one-row lens 2 and the light-transmissive substrate sheet row 12 can be cut simultaneously, the cutting process can be reduced, and further, the lens 2 and the light-transmitting light can be transmitted. It becomes possible to manufacture without causing a shift from the conductive substrate sheet row 12, and it is possible to provide an inexpensive and high-quality optical member 10.

[Embodiment 2]
Another embodiment of the present invention will be described below with reference to FIG.

  Configurations other than those described in the present embodiment are the same as those in the first embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of Embodiment 1 are given the same reference numerals, and explanation thereof is omitted.

  FIG. 8 is a cross-sectional view showing a schematic configuration of the optical member 30 of the present embodiment.

  As shown in FIG. 8, the optical member 30 of the present embodiment has an infrared wavelength cut at the outer peripheral portion of the lens effective diameter R of the flat surface (first flat surface) that is the opposite surface of the aspherical surface of the lens 32. A polymer resin lens 32 having a minute protrusion 39 as an outer peripheral protrusion projecting toward the film 3 side, and a seal resin 38 on the outer periphery of the lens 32 are provided. The minute protrusions 39 are in contact with the infrared wavelength cut film 3 on the light transmissive substrate 1. Further, the protruding microprojection 39 and the infrared wavelength cut film 3 are fixed by the sealing resin 38 from the outside of the microprojection 39.

  That is, in the lens 2 of the first embodiment, the outer peripheral portion is flatter than the lens effective diameter R on the opposite surface of the aspheric surface, whereas in the present embodiment, the lens 32 is opposite to the aspheric surface. The surface has a minute protrusion 39 protruding from the outer periphery of the lens effective diameter R. With this configuration, the air layer 5 surrounded by the lens 32 and the light transmissive substrate 1 is formed.

  The lens 32 is produced by molding a polymer resin by an injection molding method, and one surface has an aspherical shape, and a flat portion and a small protruding portion 39 projecting on the opposite surface. Therefore, the inside of the lens effective diameter R is a flat portion. Also, as shown in FIG. 8, the aspherical shape of the lens 32 has the same configuration as that of the aspherical surface of the lens 2 of the first embodiment, and a description thereof will be omitted.

  According to said structure, since the incident angle is reduced with respect to the infrared wavelength cut film 3, the lens 32 can improve the performance which cuts the infrared light of an outer peripheral part rather than the lens effective diameter R. . As a result, it is possible to suppress color unevenness caused by the red light being cut.

  The lens 32 has a flat surface (first flat surface) on the opposite side of the aspherical surface. Then, an antireflection film 4 is formed on the flat surface by vapor deposition so as to cover the flat surface.

  Here, when a mask is not used in the vapor deposition method when forming the antireflection film 4, the film is also formed on the outer peripheral portion of the lens effective diameter R other than the flat portion, that is, on the minute protrusion 39. However, the antireflection film 4 formed on the outer peripheral portion of the lens effective diameter R is so thin that the thickness of the antireflection film 4 can be ignored. Therefore, the thickness of the air layer 5 varies depending on the thickness of the antireflection film 4. In addition, it is considered that the parallelism between the flat portion of the light-transmitting substrate 1 and the flat surface of the lens 32 does not change.

  Thus, in the present embodiment, since the minute protrusion 39 of the lens 32 is provided, the air layer 5 that is a minute gap is formed between the light-transmitting substrate 1 and the lens 32. The minute protrusion 39 is a part of the lens 32, and the height of the protrusion can be precisely controlled. For this reason, there is an effect that the control of the thickness becomes easier than the sealing resin 8 used in the first embodiment. Therefore, it is difficult for an inclination to occur between the flat surface of the lens 32 and the flat surface of the light-transmitting substrate 1. That is, the parallelism between the lens 32 and the light transmissive substrate 1 can be maintained. As a result, the optical axis is less likely to be displaced, so that the reliability of the optical system can be improved.

  Further, by providing the lens 32 with the minute projection 39, the adhesion area between the light transmissive substrate 1 and the lens 32 is reduced, so that the linear expansion between the resin lens 32 and the glass light transmissive substrate 1 is reduced. Peeling due to the difference can be prevented. Further, as described above, since the sealing resin 38 and the infrared wavelength cut film 3 on the light-transmitting substrate 1 do not contact with each other at the inner periphery of the lens effective diameter R, the infrared wavelength caused by the resin adhesive Damage to the cut film 3 due to scratches and erosion can be suppressed, and a highly durable optical member 10 can be provided.

  Further, the lens 32 and the light transmissive substrate 1 are bonded by a sealing resin 38. The sealing resin 38 is a photo-curing adhesive having adhesiveness to inorganic materials and organic materials. The air layer 5 may be dewed when moisture in the atmosphere flows in. In addition, when dust or the like in the atmosphere is mixed into the air layer 5, dust or the like may adhere on the infrared wavelength cut film 3 or the antireflection film 4. Therefore, it is preferable that the lens 32 and the light-transmitting substrate 1 are completely sealed with the sealing resin 38 in order to prevent dust adhesion and dew condensation.

  Moreover, the optical member 30 of this Embodiment is used as a dust-proof cover of an image pick-up element package similarly to the optical member 10 of the said Embodiment 1. FIG.

  In the present embodiment, the lens 32 is provided with the minute protrusions 39. However, when glass is used as the lens material, or when the minute protrusions 39 cannot be formed by molding because the lens size is small, the lens 32 is minute. Instead of the protrusion 39, a metal or resinous spacer (not shown) may be used. The same effect can be obtained by arranging the light transmissive substrate 1 and the lens 32 with the spacer interposed therebetween, and then fixing the peripheral portion with the sealing resin 38 so as not to affect the thickness of the spacer. Further, by using a light shielding material such as black as a spacer, it is possible to suppress unnecessary light that causes flare and ghost generated in the camera module having the optical system shown in FIG.

[Embodiment 3]
The following will describe still another embodiment of the present invention with reference to FIG. The configurations other than those described in the present embodiment are the same as those in the first embodiment and the second embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of Embodiment 1 and Embodiment 2 are given the same reference numerals, and the description thereof is omitted.

  FIG. 9 is a cross-sectional view showing a schematic configuration of the optical member 40 of the present embodiment.

  The optical member 40 of the present embodiment does not have the antireflection film 4 as compared with the optical member 10 of the first embodiment, and is composed of the lens 2 and the infrared wavelength cut film 3 that are in contact with each other. However, the two contact surfaces are not bonded, and both are fixed by a seal resin 18 provided on the outer surface side of the lens 2 that is the outer peripheral portion of the lens effective diameter R.

  That is, as described in the first embodiment, in order to fix the lens 2 and the infrared wavelength cut film 3 in the optical member 10 of FIG. 1, a seal is provided between the lens 2 and the infrared wavelength cut film 3. Resin 8 is used. As a result, since the air layer 5 is formed, incident light is inevitably reflected at the boundary between the lens 2 and the air layer 5, and light loss is caused by a decrease in the amount of incident light. . Therefore, in the first embodiment, by providing the antireflection film 4, the reflection of incident light can be suppressed and the loss of light can be reduced.

  On the other hand, in the present embodiment, the lens 2 and the infrared wavelength cut film 3 are in contact with each other, and the sealing resin 18 is provided outside the lens 2 so that the lens 2 and the infrared wavelength cut film are cut. The membrane 3 is fixed.

  According to this configuration, no air layer is formed between the lens 2 and the infrared wavelength cut film 3, and the lens 2 and the infrared wavelength cut film 3 are brought into contact with each other, whereby the light transmissive substrate 1 is refracted. Since the relationship between the refractive index n2 and the refractive index n1 of the lens 2 is n1≈n2 (a slightly different degree), incident light is hardly reflected. Therefore, the antireflection film can be omitted.

  As a result, the number of parts can be reduced.

[Embodiment 4]
The following will describe still another embodiment of the present invention with reference to FIGS. Configurations other than those described in the present embodiment are the same as those in the first to third embodiments.

  FIG. 10 is a cross-sectional view illustrating a schematic configuration of an imaging device 70 including the optical member 50 of the present embodiment.

  The imaging device 70 according to the present embodiment includes a solid-state imaging element 56. In the present embodiment, a spacer 57 is disposed on the solid-state image sensor 56, and a light transmissive substrate 51 included in the optical member 50 is disposed thereon. With this configuration, the solid-state imaging device 56 and the light transmissive substrate 51 can be spaced without using the package 7 as described in the first embodiment. Moreover, since the space | interval of the solid-state image sensor 56 and the light transmissive board | substrate 51 can be controlled by the spacer 57, the distance of the light transmissive board | substrate 51 and the solid-state image sensor 56 can be shortened, and the space-saving image pickup device 70 is provided. Can be provided.

  In the present embodiment, in order to protect the light transmissive substrate 51 and the solid-state imaging device 56 from dust and moisture in the atmosphere, the periphery is sealed with a thermoplastic resin 55. Therefore, the resin 55 is in contact with the side wall 51 b of the light transmissive substrate 51.

  At this time, the resin 55 can be formed into a target shape by using a mold. Here, the surface of the resin 55 on the lens 52 side is preferably a flat surface 55a as a fifth flat surface. If the flat surface 55a is made parallel to the flat surface 51a as the fourth flat surface of the light-transmitting substrate 51, which is a reference surface for assembling and adjusting the optical system, it can be similarly used as the reference surface. Moreover, in order to use it as a surface which adhere | attaches the lens 52, it is preferable that it is a parallel and flat surface.

  Here, the flat surface 55a of the resin 55 can exist up to the same plane as the flat surface 51a of the light-transmitting substrate 51, but if possible, it should not be on the same plane, that is, the flat surface 55a is flat surface 51a. Is preferably lower. If they are on the same plane, when the resin 55 is molded, the resin 55 wraps around the flat surface 51a of the light-transmitting substrate 51, and the yield of the imaging device 70 is extremely reduced.

  An infrared wavelength cut film 53 is formed on the flat surface 51 a of the light transmissive substrate 51, and a lens 52 is provided on the upper side.

  The lens 52 has a flat surface 52a as a third flat surface on the infrared wavelength cut film 53 side. In addition, the lens effective diameter D of the lens 52 is equal to or smaller than the outer dimension of the light transmissive substrate 51, and all effective light beams pass through the light transmissive substrate 51 and are photoelectrically converted by the solid-state imaging device 56. The outer diameter of the lens 52 is larger than the outer dimension of the light transmissive substrate 51, and is a size that protrudes from the light transmissive substrate 51.

  Here, the lens 52 comes into contact with a part of the surface of the infrared wavelength cut film 53 provided on the flat surface 52a which is a reference surface, and the inclination is adjusted. Further, the position of the lens 52 is adjusted in the in-plane direction while being observed from a light incident direction by a camera (not shown). With the above adjustment, the position adjustment and tilt adjustment of the lens 52 are completed.

  The lens 52 is fixed outside the lens effective diameter D by a flat surface 55a of the resin 55 and a sealing resin 58 as an adhesive. At this time, the lens 52 and the infrared wavelength cut film 53 are in contact with each other, but are not bonded. For this reason, it is possible to suppress peeling of the lens 52 due to a difference in linear expansion due to fixation between the lens made of resin and the infrared wavelength cut film 53 made of glass. In addition, since the lens 52, the seal resin 58, and the resin 55 are all resins, the linear expansion coefficients are similar, and the lens is peeled off as compared with the case where it is formed on the infrared wavelength cut film 53 made of glass. hard. Moreover, since resin has good adhesiveness and adhesiveness, lens peeling can be prevented.

  FIG. 11 shows a plan view of the imaging device 70. For the sake of simplicity, only the outer shape of the lens 52 is shown. The light-transmitting substrate 51 is rectangular and all four corners are covered with lenses 52. The resin 55 is square when viewed from above, and is larger than the lens 52.

  Here, the lens 52 is fixed by the sealing resin 58 in the region 52b. That is, all the gaps caused by the step between the flat surface 52 a of the lens 52 and the resin 55 other than the surface in contact with the light transmissive substrate 51 are filled with the seal resin 58. Thereby, the lens crack and seal resin crack from a clearance gap can be eliminated.

  A modification of the imaging device 70 will be described. FIG. 14 is a plan view showing an imaging device 70 a which is a modification of the imaging device 70.

  In the imaging device 70a, the lens 62 (only the outer shape is illustrated) is formed small, and a part of the outer diameter overlaps the light-transmitting substrate 51 and a part overlaps the seal resin 58. In such a state, the lens 62 has the flat surface 52a on the light transmissive substrate 51 side, and the flat surface 52a and the infrared wavelength cut film 53 provided on the light transmissive substrate 51 are in contact with each other. Yes. Further, a gap is formed between the lens 62 and the resin 55 at a portion that is not in contact, that is, a portion indicated by a region 62b. Therefore, the lens 62 and the resin 55 are bonded together by filling the region 62b with the sealing resin 58.

  Thus, by reducing the outer diameter of the lens 62, the amount of resin that is a raw material of the lens 62 can be reduced, and a lower-cost imaging device 70a can be provided.

  Incidentally, the flat surface 51 a of the light transmitting substrate 51 and the flat surface 55 a of the resin 55 shown in FIGS. 11 and 12 are not on the same plane, and the outer diameters of the lenses 52 and 62 are larger than those of the light transmitting substrate 51. If it is too large or partially large, the resin for forming the lenses 52 and 62 cannot be directly cured on the light transmissive substrate 51.

  Therefore, in the present embodiment, it is conceivable to form the lenses 52 and 62 made of resin by the following method. A method for manufacturing the lenses 52 and 62 will be described with reference to FIGS. 12 and 13A and 13B. FIG. 13A shows the A-A ′ section of FIG. 12, and FIG. 13B shows the B-B ′ section of FIG. 12.

  As shown in FIGS. 13A and 13B, the resin for forming the lenses 52 and 62 is a photo-curing photo-curing resin 71, which is cured by irradiation with ultraviolet light. The glass mold 72 is a mold made of a light-transmitting inorganic substance such as borosilicate glass or quartz such as “BK7” manufactured by SCHOTT GLAS, and transmits ultraviolet rays. The glass mold 72 is filled with a photo-curing resin 71 up to the reference surface 72a of the mold, and the photo-curing resin 71 and the reference surface 72a of the glass mold 72 are on the same plane. After the reference surface 72a of the glass mold 72 and the light-transmitting substrate 51 are brought into contact with each other for alignment, the light curable resin 71 is cured by irradiating ultraviolet light from below the paper surface through the glass mold 72 and curing the light curable resin 71. The lens 52 * 62 which consists of is formed.

  However, actually, in this step, it is not possible to form the lenses 52 and 62 made of the photo-curing resin 71 on the light-transmitting substrate 51. That is, in the cross-section AA ′, the reference surface 72a of the glass mold 72 and the light-transmitting substrate 51 (exactly the infrared wavelength cut film 53) are in close contact with each other at the outer peripheral portion, but the cross-section BB In ', since the diameter of the glass mold 72 is larger than that of the light-transmitting substrate 51, a minute gap 73 between the photocurable resin 71 and the resin 55 is generated.

  At this time, the photo-curing resin 71 is not yet cured and flows because it is in a liquid state, and moves to the minute gap 73 by capillary action. For this reason, in the glass mold | type 72, the air corresponding to the moved photocurable resin 71 minutes flows in, and the subject that a lens shape cannot be formed arises.

  That is, when the flat surface 51a of the light transmissive substrate 51 and the flat surface 55a of the resin 55 are not on the same plane and the outer shape of the lenses 52 and 62 is larger than that of the light transmissive substrate 51, the photo-curing resin 71 is used. It cannot be formed directly. Therefore, in this embodiment, after the lenses 52 and 62 are separately formed in advance, the lenses 52 and 62 are bonded to the light-transmitting substrate 51 and the flat surface 55 a of the resin 55.

  As described above, in the optical member 50 of the present embodiment, the infrared wavelength cut film 53 is provided on the light transmissive substrate 51, and further, a lens having a flat surface 52a on the infrared wavelength cut film 53 side on the upper side. 52, and a resin 55 is provided so as to be in contact with the side wall 51b of the light transmissive substrate 51, and the lens 52 is fixed to the resin 55 at the outer peripheral portion rather than the lens effective diameter D.

  Accordingly, the lens 52 is not fixed to the infrared wavelength cut film 53 made of, for example, glass within the lens effective diameter D. Therefore, when the lens 52 made of, for example, the resin 55 is directly formed on the infrared wavelength cut film 53 made of, for example, glass, or the lens 52 made of, for example, resin is attached to the infrared wavelength cut film 53 made of, for example, glass Can be prevented from peeling due to the difference in linear expansion between the lens 52 and the infrared wavelength cut film 53 (no peeling occurs).

  Further, according to the above configuration, the lens 52 is bonded to the resin 55 outside the lens effective diameter D. Therefore, when compared with the case where the infrared wavelength cut film 53 and the lens 52 are bonded, the infrared wavelength cut film 53 is peeled off from the light transmissive substrate 51, so that the lens 52 is peeled off from the light transmissive substrate 51 at the same time. Can solve the problem.

  In the optical member 50 of the present embodiment, the light transmissive substrate 51 has a flat surface 51 a on the lens 52 side, while the infrared wavelength cut film 53 is provided on the flat surface 51 a of the light transmissive substrate 51. It is preferable that

  Thus, the infrared wavelength cut film 53 is formed on the flat surface 51 a of the light transmissive substrate 51, thereby producing the infrared wavelength cut film 53 on the three-dimensional surface of the light transmissive substrate 51. Therefore, the optical member 50 with lower cost and higher performance can be provided.

  In the optical member 50 of the present embodiment, the planar shape of the lens 52 when viewed from the optical axis direction of the lens 52 is the planar shape of the light-transmitting substrate 51 and the partial planar shape of the resin 55. It is preferable to include.

  Further, in the optical member 50 of the present embodiment, the planar shape of the lens 62 when viewed from the optical axis direction of the lens 62 is a part of the planar shape of the light transmissive substrate 51 and a part of the resin. It preferably includes a planar shape.

  Thereby, the lens 52 is completely formed on the light transmissive substrate 51, and the lens 62 is substantially formed on the light transmissive substrate 51. Therefore, the light can be refracted by the optical performance of the lenses 52 and 62 and guided to the solid-state image sensor 56 through the light-transmitting substrate 51. In addition, it is possible to create a bonding location where the lenses 52 and 62 and the resin 55 can be bonded except on the light-transmitting substrate 51. As a result, the adhesive force of the lenses 52 and 62 can be increased as compared with the case of bonding to the light transmissive substrate 51, and the optical member 50 with higher reliability can be provided.

  In the optical member 50 of the present embodiment, the resin 55 has a flat surface 55a parallel to the flat surface 51a of the light-transmitting substrate 51 on the lens 52/62 side. It is preferable that the flat surface 55a of the resin 55 is fixed with an adhesive.

  Accordingly, the resin 55 can be molded with the flat surface 51a of the light transmissive substrate 51 as a reference, and the flat surface 55a of the resin 55 can be used as a reference for the optical system. Furthermore, by attaching 52 and 62 to the flat surface 55a, the lens 52 and 62 can be adjusted with less inclination, and the reliability of the optical system can be increased.

  Further, in the optical member 50 of the present embodiment, the flat surface 55a of the resin 55 exists on the same plane as the flat surface 51a of the light transmissive substrate 51, or is closer to the lenses 52 and 62 than the flat surface 51a. It is preferable not to protrude.

  In this configuration, the resin 55 surrounds the light transmissive substrate 51. Thus, the light transmissive substrate 51 is positioned within the lens effective diameter D, while the resin 55 is positioned outside the lens effective diameter D. Therefore, by bonding the lenses 52 and 62 and the resin 55 outside the lens effective diameter D, it is possible to provide the optical member 50 in which peeling of the light transmissive substrate 51 with respect to the lenses 52 and 62 is suppressed.

  In the optical member 50 of the present embodiment, the flat surface 51 a of the light transmissive substrate 51 is preferably disposed closer to the flat surface 52 a of the lenses 52 and 62 than the flat surface 55 a of the resin 55.

  In this configuration, the flat surface 55 a of the resin 55 is lowered by one step from the flat surface 51 a of the light transmissive substrate 51. Thereby, when the periphery of the light transmissive substrate 51 is filled with the resin 55, the problem that the resin 55 wraps around the surface of the flat surface 51a of the light transmissive substrate 51 can be solved.

  Further, the imaging devices 70 and 70a of the present embodiment are imaging devices including the optical member 50 described above, and the optically transparent substrate 51 of the optical member 50 is disposed on the side opposite to the lenses 52 and 62. The solid-state image sensor 56 is provided, and the solid-state image sensor 56 is sealed with a resin 55.

  As a result, it is possible to form 70 and 70a in which the lenses 52 and 62 are directly formed, and it is possible to provide thin and small 70 and 70a.

[Embodiment 5]
The following will describe still another embodiment of the present invention with reference to FIG. Configurations other than those described in the present embodiment are the same as those in the first to fourth embodiments.

  FIG. 14 is a cross-sectional view illustrating a schematic configuration of an imaging device 90 including the optical member 80 of the present embodiment.

  The imaging device 90 has a flat surface 82a as a third flat surface on the opposite side of the aspherical surface of the lens 82, and minute protrusions as outer protrusions protruding toward the resin 55 at the outer periphery of the lens effective diameter D. A resin lens 82 having a portion 82 b and a sealing resin 88 as an adhesive are provided on the outer periphery of the lens 82.

  The minute protrusions 82 b are in contact with the flat surface 55 a of the resin 55. Further, the protruding microprojection 82b and the flat surface 55a of the resin 55 are fixed by the seal resin 88 from the outside of the microprojection 82b.

  In other words, in the lenses 52 and 62 of the fourth embodiment, the outer peripheral portion is a flat surface 52a rather than the lens effective diameter D on the opposite surface of the aspherical surface. The opposite surface of the spherical surface has a minute protrusion 82b protruding from the outer periphery of the lens effective diameter D. With this configuration, an air layer 85 surrounded by the lens 82 and the light transmissive substrate 51 is formed.

  The minute protrusion 82b is a part of the lens 82, and can accurately control the height of the protrusion. For this reason, there exists an effect that control of the thickness of the lens 82 becomes easy, and the reliability of an optical system can be improved.

  The flat surface 82a of the lens 82 is provided with an antireflection film 84 as a third antireflection film. Thereby, reflection of incident light caused by a difference in refractive index between the lens 82 and the air layer 85 can be suppressed. Therefore, it is possible to provide the optical member 80 with less flare light and the imaging device 90 including the same.

  The air layer 85 includes an antireflection film 84 provided on the flat surface 82 a of the lens 82, an infrared wavelength cut film 53 provided on the flat surface 51 a of the light transmissive substrate 51, and a minute protrusion of the lens 82. 82b and the sealing resin 88 are hermetically sealed. As a result, it is possible to prevent dust from entering the air layer 85 and to prevent dew from moisture components in the atmosphere.

  As described above, in the optical member 80 according to the present embodiment, the outer peripheral portion of the lens 82 than the lens effective diameter D protrudes toward the flat surface 55a of the resin 55, and the flat surface 82a of the lens 82 and the light transmitting substrate. A minute projection 82b that provides an air layer 85 between the flat surface 51a and the flat surface 51a is formed so as to contact the flat surface 55a.

  Therefore, since the optical axis is hardly displaced, the reliability of the optical system can be improved.

  Further, since the air layer 85 is provided, the lens 82 and the light transmissive substrate 51 are not in direct contact with each other, and the light transmissive substrate 51 is peeled off from the lens 82 due to a difference in linear expansion, or the infrared wavelength cut film 53 due to the resin 55. Damage to the can be suppressed.

  Further, in the optical member 80 of the present embodiment, it is preferable that an antireflection film 84 is provided on the flat surface 82 a of the lens 82.

  Thereby, the Fresnel reflection by the difference in the refractive index of the lens 82 and the air layer 85 can be suppressed, and the flare light observed as an imaging system as a result can be suppressed.

  Further, in the optical member 80 of the present embodiment, the air layer 85 includes the antireflection film 84 provided on the flat surface 82 a of the lens 82, the minute protrusion 82 b, and the red provided on the light transmissive substrate 51. The outer wavelength cut film 53 and the flat surface 55a of the resin 55 are sealed.

  Thereby, it is possible to prevent the intrusion of water derived from moisture in the atmosphere and the like, and to suppress the dew on the lens 82, so that the optical member 80 having environmental resistance can be provided.

  In addition, the imaging device 90 of the present embodiment is an imaging device including the optical member 80, and a solid-state imaging device 56 is provided on the side of the optical member 80 opposite to the lens 82 of the light transmissive substrate 51. The solid-state imaging device 56 is sealed with a resin 55 while being provided.

  Therefore, the imaging device 90 in which the lens 82 is directly formed can be formed, and a thin and small imaging device 90 can be provided.

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

  INDUSTRIAL APPLICABILITY The present invention is applied to an optical member in which an infrared wavelength cut film made of glass is provided on a light-transmitting substrate made of an inorganic material, and a lens made of resin is further provided thereon, and an imaging device including the same it can.

1 shows an embodiment of an optical member in the present invention, and is a cross-sectional view illustrating a schematic configuration of the optical member. It is sectional drawing which shows schematic structure of the image pick-up element device provided with the said optical member. It is sectional drawing which shows the optical path in the optical system of the said image pick-up element device. It is sectional drawing which shows the other aspherical shape of the lens in the said optical member. The manufacturing method of the said lens is shown, Comprising: (a) is a top view which shows a lens sheet, (b) is a side view which shows a lens sheet. The other manufacturing method of the said lens is shown, Comprising: (a) is a top view which shows a lens sheet and a transparent substrate sheet, (b) stuck the lens sheet and the transparent substrate sheet. It is a side view which shows a thing. The other manufacturing method of the said lens is shown, Comprising: (a) is a top view which shows a lens sheet row | line | column and a light transmissive substrate sheet row | line | column, (b) is a lens sheet row | line | column, a light transmissive substrate sheet row | line | column, It is a side view which shows what affixed. The other embodiment of the optical member in this invention is shown, and it is sectional drawing which shows the schematic structure of an optical member. FIG. 7 is a cross-sectional view illustrating a schematic configuration of an optical member according to still another embodiment of the optical member of the present invention. The optical member in this invention and other embodiment of an imaging device provided with the same are shown, It is sectional drawing which shows schematic structure of an optical member and an imaging device provided with the same. It is a top view which shows schematic structure of the said optical member and an imaging device provided with the same. It is a top view which shows schematic structure of the modification of the said optical member and an imaging device provided with the same. (A) is the sectional view along the A-A 'line in FIG. 12, and (b) is the sectional view along the B-B' line in FIG. The optical member in this invention and other embodiment of an imaging device provided with the same are shown, It is sectional drawing which shows schematic structure of an optical member and an imaging device provided with the same. It is a sectional view showing a conventional example and showing a schematic configuration of an imaging device. It is sectional drawing which shows another prior art example and shows the schematic structure of an imaging device.

Explanation of symbols

1 Light-transmissive substrate 1a Flat surface (second flat surface)
2 Lens 2a Flat surface (first flat surface)
2S lens 3 Infrared wavelength cut film 4 Antireflection film (first antireflection film)
5 Air Layer 6 Solid Image Sensor 7 Package 8 Sealing Resin (Adhesive)
DESCRIPTION OF SYMBOLS 10 Optical member 11 Light transmissive substrate sheet 12 Light transmissive substrate sheet row 18 Seal resin 20 Image sensor device 21 Aperture 22 First lens group 23 Second lens groups 25 and 26 Lens sheet 27 Lens sheet row 30 Optical member 32 Lens 38 Seal resin 39 Micro protrusion (outer peripheral protrusion)
40 Optical member 50 Optical member 51 Light transmitting substrate 51a Flat surface (fourth flat surface)
51b Side wall 52 Lens 52a Flat surface (third flat surface)
52b region 55 resin 53 infrared wavelength cut film 55a flat surface (fifth flat surface)
56 Solid-state image sensor 57 Spacer 58 Seal resin (adhesive)
62 Lens 62b Region 70 Imaging device 70a Imaging device 71 Photocurable resin 72 Glass mold 72a Reference surface 73 Gap 80 Optical member 82 Lens 82a Flat surface (third flat surface)
82b Minute protrusion (outer peripheral protrusion)
84 Antireflection film (third antireflection film)
85 Air layer 88 Seal resin (adhesive)
D Effective lens diameter

Claims (28)

An infrared wavelength cut film is provided on the light transmissive substrate, and further, a lens having a first flat surface on the infrared wavelength cut film side is provided on the upper side,
The optical member, wherein the lens is fixed to the light-transmitting substrate at an outer peripheral portion with respect to an effective lens diameter. While the light transmissive substrate has a second flat surface on the lens side,
The optical member according to claim 1, wherein the infrared wavelength cut film is provided on a second flat surface of the light transmissive substrate.   The optical member according to claim 1, wherein a first antireflection film is provided between the lens and the infrared wavelength cut film.   The optical member according to claim 3, wherein the first antireflection film is provided on a first flat surface of the lens.   5. The optical member according to claim 3, wherein the first antireflection film faces the infrared wavelength cut film through an air layer.   The air layer is sealed with the infrared wavelength cut film, the first antireflection film, and an adhesive that fixes the infrared wavelength cut film and the lens. Item 6. The optical member according to Item 5.   An outer peripheral protrusion that protrudes toward the infrared wavelength cut film side and has an air layer between the infrared wavelength cut film and the first antireflection film is provided on the outer peripheral part of the effective diameter of the lens. The optical member according to claim 6, wherein the optical member is formed so as to contact the infrared wavelength cut film.   The air layer is sealed with the infrared wavelength cut film, the first antireflection film, the outer peripheral protrusion, and an adhesive that fixes the outer peripheral protrusion and the first antireflection film. The optical member according to claim 7, wherein the optical member is formed.   9. The lens according to claim 1, wherein the lens is formed so that a cross section of a side surface opposite to the surface facing the light-transmitting substrate has an aspherical shape. Optical member.   The lens is formed such that a cross section of the side surface opposite to the surface facing the light-transmitting substrate has an aspherical shape having a maximum thickness between the optical axis central portion and the outer periphery of the lens effective diameter. The optical member according to claim 9.   In the lens, the cross section of the side opposite to the surface facing the light-transmitting substrate has a maximum value at the center of the optical axis, and has a minimum thickness between the outer periphery of the lens effective diameter and the outermost periphery of the lens. The optical member according to claim 9, wherein the optical member is formed in an aspherical shape.   12. The optical device according to claim 1, wherein a second antireflection film is formed on the lens on the side surface opposite to the surface facing the light transmissive substrate. Element.   The optical member according to claim 1, wherein a plurality of the lenses are manufactured in the form of a sheet of one row.   The optical member according to claim 13, wherein the manufactured single-row sheet-like lenses are individually separated after being provided on a light-transmitting substrate.   The optical member according to claim 1, wherein a plurality of the lenses are manufactured in an array.   The optical member according to claim 15, wherein the manufactured array-like lenses are individually separated after being provided on the light-transmitting substrate. An imaging device comprising the optical member according to any one of claims 1 to 16,
On the opposite side of the light transmissive substrate in the optical member from the lens, a package having an opening on the light transmissive substrate side is provided,
An imaging device comprising: a solid-state imaging device fixed to the package; and a light-transmitting dustproof cover that covers the solid-state imaging device and closes the opening. . An infrared wavelength cut film is provided on the light transmissive substrate, and a lens having a third flat surface on the infrared wavelength cut film side is provided on the upper side thereof, and is in contact with the side wall of the light transmissive substrate. Is provided with resin,
The optical member is characterized in that the lens is fixed to the resin at an outer peripheral portion rather than an effective lens diameter. While the light transmissive substrate has a fourth flat surface on the lens side,
The optical member according to claim 18, wherein the infrared wavelength cut film is provided on a fourth flat surface of the light transmissive substrate.   The planar shape of the lens as viewed from the optical axis direction of the lens includes the planar shape of the entire light-transmitting substrate and the planar shape of a part of the resin. Optical member.   The planar shape of the lens as viewed from the optical axis direction of the lens includes a partial planar shape of the light-transmitting substrate and a partial planar shape of the resin. 19. The optical member according to 19. The resin has a fifth flat surface parallel to a fourth flat surface of the light-transmitting substrate on the lens side,
The optical member according to claim 20 or 21, wherein the lens is fixed to the fifth flat surface of the resin by an adhesive.   The fifth flat surface of the resin exists on the same plane as the fourth flat surface of the light-transmitting substrate, or does not protrude to the lens side with respect to the fourth flat surface. The optical member according to claim 22.   23. The optical member according to claim 22, wherein the fourth flat surface of the light-transmitting substrate is disposed closer to the third flat surface of the lens than the fifth flat surface of the resin. .   The outer peripheral portion of the lens has an effective diameter that protrudes toward the fifth flat surface of the resin, and air between the third flat surface of the lens and the fourth flat surface of the light-transmitting substrate. 25. The optical member according to claim 23 or 24, wherein an outer peripheral protrusion portion on which the layer is provided is formed so as to abut on the fifth flat surface.   26. The optical member according to claim 25, wherein a third antireflection film is provided on the third flat surface of the lens.   The air layer includes a third antireflection film provided on a third flat surface of the lens, the outer peripheral projection, an infrared wavelength cut film provided on the light transmitting substrate, and the resin. The optical member according to claim 26, wherein the optical member is sealed with the fifth flat surface. An imaging device comprising the optical member according to any one of claims 18 to 27,
On the opposite side of the light transmissive substrate in the optical member from the lens, a solid-state imaging device is provided,
The solid-state imaging device is sealed with the resin, and the imaging device is characterized in that

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