JP2018097248A - Imaging device, and imaging device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup apparatus capable of efficiently dissipating heat generated from an image pickup device or an image pickup element substrate to another member. An image pickup device of the present invention is an image pickup device that acquires a photographed image by forming a subject light on an image pickup element by a lens optical system, and is an image pickup element substrate and an image pickup element substrate on which the image pickup element and the image pickup element are mounted. It has an image sensor unit made of a heat-dissipating metal plate that supports the image sensor, and a lens mount for mounting the lens optical system. It has a main frame in which through holes of m rows and n columns are formed at positions overlapping with the image sensor unit, and thermal conductivity is provided between the main frame and the heat-dissipating metal plate around the through holes formed in the main frame. It is characterized by being filled with an adhesive. [Selection diagram] Fig. 1

Description

  The present invention relates to an imaging apparatus and a manufacturing method of the imaging apparatus, and more particularly to a heat dissipation structure of an imaging apparatus for effectively radiating heat generated in an imaging element or the like to other members.

  In recent years, apart from single-lens reflex digital cameras, where a quick return mirror is placed in the middle of focusing the light flux from the photographic lens onto the image sensor and the subject is observed with an optical viewfinder, the quick return mirror is not placed and the image sensor is connected. A mirrorless type digital camera that observes an image of a subject with an electronic viewfinder has appeared. A mirrorless type digital camera does not require a quick return mirror and does not require a mechanism such as a pentaprism for mounting an optical viewfinder.

  On the other hand, in a mirrorless type digital camera, since the subject image formed on the image sensor is observed with an electronic viewfinder, it is necessary to always operate the image sensor during exposure and during live view. There was a possibility that the heat generated from the element or the like would be a problem. In order to acquire image data with the image sensor, it is necessary to control the reading and transfer of image data from the image sensor, image signal processing, image display, etc., especially during live view or continuous shooting. Since it is necessary to repeat, heat generated in the image sensor and the image sensor substrate tends to increase.

  If heat generated from the image sensor or the image sensor substrate accumulates in the housing of the digital camera, there is a danger that the user may touch the high heat housing and get a low temperature burn. Even if the entire digital camera housing does not become hot, if the heat is not properly released from the image sensor or image sensor substrate, the circuit inside the digital camera will run out of heat or thermal noise will occur in the image data. Or the possible shooting time is limited for the purpose of preventing breakage due to heat.

  Conventionally, techniques for dissipating heat generated from an image sensor and an image sensor substrate of a digital camera to other members are disclosed in patent documents and the like. Patent Document 1 discloses a heat dissipation structure that dissipates heat from an image pickup device and an image pickup board on which the image pickup device is mounted to a housing. In particular, an urging force that causes flange back displacement with respect to an image sensor after flange back adjustment is disclosed. A non-working heat dissipation structure is disclosed.

Japanese Patent Laid-Open No. 2006-19005

  In the heat dissipating structure disclosed in Patent Document 1, heat from the image sensor and the image sensor substrate is radiated to the metal casing without affecting the flange back adjustment, so that the washer capable of adjusting the flange back of the image sensor unit. A heat radiating structure is constituted by employing a cum radiating member.

  However, in the heat dissipating structure disclosed in Patent Document 1, the heat transfer path between the washer / heat dissipating member and the front base which is the metal housing is configured by fastening with an adjusting screw and connection of a flexible heat conductive sheet. It is complex and limited. The heat transfer path is configured by sandwiching a heat conductive rubber between the image sensor unit and the washer / heat dissipating member, but the elastic rubber compresses and distorts the image sensor and image sensor substrate. There is a possibility that the image plane of the image sensor may be affected, and pressure is applied to the electronic components mounted on the substrate, which is not preferable.

  The present invention does not affect the position of the image sensor unit after the flange back has been adjusted, and the heat transfer path from the image sensor unit to the metal housing can have a wider cross-sectional area. An object of the present invention is to provide an imaging apparatus capable of efficiently dissipating heat generated from an imaging element or an imaging element substrate to another member.

  In order to solve the above-described problem, an imaging apparatus according to a first aspect of the present invention is an imaging apparatus that acquires a captured image by imaging subject light on an imaging element by a lens optical system. An image pickup device substrate on which an element is mounted, an image pickup device unit comprising a heat dissipating metal plate for fixing the image pickup device substrate, a lens cover for mounting a lens optical system, and a front cover for fixing the image pickup device unit; A front frame is fixed and a main frame in which through holes of m rows and n columns are formed at positions overlapping the image sensor unit when viewed from the optical axis direction of the image sensor, and the through holes formed in the main frame A space between the main frame and the heat radiating metal plate is filled with a heat conductive adhesive around.

  The image pickup apparatus according to a second aspect of the present invention is characterized in that thermally conductive clay is stuck to the heat radiating metal plate between the heat radiating metal plate and the main frame.

The imaging device according to a third aspect of the present invention is characterized in that m through n columns of through holes formed in the main frame satisfy the following conditions.
r <(2-√2) × l
However,
r: Diameter of the through hole l: Shortest distance among the distances between the through holes adjacent in the vertical direction or the horizontal direction

  According to a third aspect of the present invention, there is provided a manufacturing method of an imaging apparatus, an imaging element unit including an imaging element, an imaging element substrate on which the imaging element is mounted, a heat dissipation metal plate that fixes the imaging element substrate, and lens optics. A front cover having a lens mount for mounting the system, and fixing the image sensor unit; and fixing the front cover and having m rows and n columns in a position overlapping the image sensor unit when viewed from the optical axis direction of the image sensor. A method of manufacturing an imaging apparatus that obtains a captured image by imaging subject light on the imaging element by a lens optical system having a main frame in which a through hole is formed, wherein the imaging element unit is attached to the front cover. A first step of adjusting the flange back when fixing, a second step of fixing the front cover to the main frame, and The heat conductive adhesive is injected from the m-row and n-column through-hole formed in the in-frame so that the space between the main frame and the heat-dissipating metal plate is filled around the through-hole formed in the main frame. And a third step.

Perspective view of an interchangeable lens digital camera as seen from the front An exploded perspective view of a part of the member fixed to the front cover as seen from the back side Exploded perspective view of heat dissipation structure from the back Rear view of heat dissipation structure AA cross section of heat dissipation structure Schematic diagram regarding the arrangement of through-holes in m rows and n columns

  Embodiments of an interchangeable lens digital camera according to an imaging apparatus of the present invention will be described below.

  FIG. 1 is a perspective view of the interchangeable lens digital camera 100 (camera body) of this embodiment as seen from the front. In FIG. 1, reference numeral 101 denotes an image sensor, 105 denotes a front cover, and 106 denotes a lens mount.

  The camera body 100 of this embodiment is a so-called mirrorless type digital camera, and no quick return mirror is provided on the object side of the image sensor 101. In a mirrorless type digital camera, an EVF (electronic viewfinder) is used instead of the optical viewfinder used in the single-lens reflex type digital camera, and the user forms a subject image formed on the image sensor 101 during shooting. The live view image acquired from the above is observed in real time with an EVF or a monitor and photographed. Accordingly, a focal plane shutter (not shown) provided on the object side of the image sensor 101 is normally open, and the light receiving surface of the image sensor 101 is exposed to the object side.

  Various information for photographing such as focus information and photographing conditions can be superimposed and displayed on the live view image. In addition to the live view image, the EVF and the monitor can also display preview and playback after shooting and setting information of the camera body.

  The front cover 105 is a member provided on the front surface of the camera body, and is a member that serves as a basis for optically adjusting and fixing a lens mount and an image sensor unit, which will be described later, mainly.

  The lens mount 106 is a member serving as a base for mounting the interchangeable lens on the camera body 100, and has a bayonet mechanism for mounting the interchangeable lens.

  The mount surface 106a of the lens mount 106 is a surface perpendicular to the optical system of the interchangeable lens to be mounted and the optical axis of the image sensor 101, and serves as a reference surface when the interchangeable lens is mounted. The distance between the surfaces of the mount surface 106a and the image sensor 101 is referred to as a flange back. In order to obtain an appropriate captured image, it is necessary to make individual adjustments strictly so that the flange back is uniform throughout the image sensor 101. . The method of individual adjustment of the flange back will be described later.

  In this embodiment, an example of a lens mount in an interchangeable lens digital camera has been described. However, when the present invention is applied to a lens-integrated digital camera, a lens barrel that holds an optical system is used in the digital camera. The part to be fixed and used as a reference for adjusting the flange back is a lens mount.

  FIG. 2 is an exploded perspective view of a part of the member fixed to the front cover 105 as viewed from the back in the camera body 100 of the present embodiment. In FIG. 2, 101 is an image sensor, 102 is an image sensor substrate, 103 is a heat radiating metal plate, 104 is an image sensor unit, 105 is a front cover, 107 is a main frame, 108 is an image sensor base, and 109 is a thermally conductive clay. Show.

  The image sensor unit 104 includes an image sensor 101, an image sensor substrate 102, and a heat radiating metal plate 103.

  The image pickup device substrate 102 is made of a glass epoxy substrate, and a circuit for processing an image signal read from the image pickup device around the image pickup device 101 is mounted.

  The heat radiating metal plate 103 fixes the image sensor substrate 102 on which the image sensor 101 is mounted. The heat radiating metal plate 103 is made of an aluminum alloy having high thermal conductivity, and has a role of radiating heat generated from the image sensor 101 and the image sensor substrate 102 to other members. In addition, since the heat radiating metal plate 103 has higher rigidity than the imaging element substrate 102 and is difficult to be deformed, it also has a role for fixing the imaging element unit 104 to the front cover 105 with high accuracy.

  The back surface opposite to the surface on which the image pickup device 101 and the image pickup device substrate 102 are arranged in the heat radiating metal plate 103 is preferably a flat surface in order to easily and uniformly apply a heat conductive adhesive described later. In this embodiment, the heat conductive clay 109 is attached to the concave shape formed on the back surface of the heat radiating metal plate 103 to form a flat surface.

  A lens mount 106 is fixed to the front surface of the front cover 105, and an imaging element unit 104 with a flange back adjusted with respect to the mount surface 106a of the lens mount 106 is fixed to the rear surface. The image sensor unit 104 of the present embodiment is fixed in a state where the optical axis is adjusted with respect to the image sensor base 108, and the image sensor unit 104 and the image sensor base 108 are integrated with the front cover 105. It is fixed to the boss formed on the back with screws. In addition, the flange back is adjusted for each individual camera body 100 by sandwiching a washer having an appropriate thickness between the imaging element base 108 and the boss of the front cover 105.

  In adjusting the flange back of the image sensor unit 104, the thickness of the washer is obtained as follows. First, a temporary thickness washer serving as a reference value is sandwiched between the image sensor base 108 and a boss formed on the back surface of the front cover 105, and the image sensor unit 104 and the image sensor base 108 are integrated into the front using screws. Secure to the cover 105. In this state, the distance between the surfaces of the lens mount 106 with respect to the image pickup device 101 with respect to the mount surface 106a is measured, a difference between this distance and an appropriate flange back is calculated, and a washer for canceling the difference is calculated. Find the thickness.

  In this embodiment, the flange back is adjusted by sandwiching a washer having an appropriate thickness between the image sensor base 108 and the front cover 105. However, the image sensor unit or the image sensor base and the front cover It is also possible to adjust the flange back by adjusting the amount of tightening of the screw so that the compression coil spring is sandwiched between them and expanded or contracted to an appropriate thickness.

  The main frame 107 is made of a magnesium alloy having excellent rigidity per unit weight, and is a member serving as a basis for fixing each member constituting the camera body. A front cover 105 to which the image sensor unit 104 and the lens mount 106 are fixed is fixed to the main frame 107. A flat portion for heat dissipation is formed in the central portion of the main frame 107, and m rows and n columns through holes for injecting a heat conductive adhesive described later are formed in the flat portion.

  Next, the heat dissipation structure in the camera body 100 of this embodiment and the manufacturing method thereof will be described.

  FIG. 3 is an exploded perspective view of the heat dissipating structure in the camera body 100 of this embodiment as viewed from the back.

  To manufacture the heat dissipation structure, as a first step, the image sensor unit 104 and the image sensor base 108 are integrally fixed to the back surface of the front cover 105. At that time, the flange back of the image sensor unit 104 is adjusted with respect to the front cover 105. The adjustment of the flange back is performed via the image sensor base 108 to which the image sensor unit 104 is fixed. The image sensor base 108 is sandwiched between the image sensor base 108 and the front cover 105 with a washer 110 having an appropriate thickness. Is fixed to a boss 105 a formed on the back surface of the front cover 105 with a screw 111.

  As a second step, the front cover 105 to which the image sensor unit 104 is fixed is fixed to the main frame 107. The front cover 105 is fixed to the main frame 107 with screws 112.

  As a third step, a space sandwiched between the heat radiating metal plate 103 of the imaging element unit 104 and the flat portion 107a of the main frame 107 from the back side of the through hole 107b formed in the flat portion 107a of the main frame 107 is filled. Inject heat conductive adhesive into When injecting the thermally conductive adhesive into the through-holes of m rows and n columns formed in the flat portion 107a of the main frame 107, one may be injected at a time or a plurality may be simultaneously injected.

  The heat conductive adhesive is premised on having a sufficient thermal conductivity, but it is preferable to select it in consideration of curing conditions and shrinkage after curing. As for the curing conditions of the thermally conductive adhesive, it is possible to improve the assembly efficiency of the camera body by considering the curing method, temperature, and time. If the curing conditions do not match the work environment when assembling the camera body, the posture cannot be changed or moved in order to prevent the uncured thermal conductive adhesive from dripping to unnecessary places. The time required to move to the assembly process will be lost.

  In addition, by taking into account the shrinkage after curing, it is possible to ensure the accuracy of flange back adjustment. The flange back adjusted in the first step is fixed so as not to change easily. However, if the shrinkage stress after curing of the heat conductive adhesive is large, the imaging element unit 104 is attracted to the main frame 107 to capture an image. The element unit 104 may be bent and the flange back may change. Further, when the shrinkage amount of the heat conductive adhesive is large, the heat conductive adhesive is peeled off from the flat surface portion 107a of the image sensor unit 104 and the main frame 107, so that heat from the image sensor 101 and the image sensor substrate 102 is transferred to the main frame. There is a possibility that the efficiency of movement to 107 is lowered.

  Next, m through n columns of through holes formed in the flat portion 107a of the main frame 107 in the heat dissipation structure of the camera body 100 of the present embodiment will be described.

  4 is a rear view after assembling the members shown in the exploded perspective view of FIG. 3 with respect to the heat dissipation structure in the camera body 100 of the present embodiment. In FIG. 4, 113 indicates a heat conductive adhesive. As will be described later, the heat conductive adhesive 113 is injected around the through hole 107 a formed in the main frame 107 so as to fill the space between the flat portion 107 a and the heat radiating metal plate 103 of the imaging element unit 104.

  In this embodiment, through holes of 4 rows and 3 columns are formed in the flat portion 107a of the main frame 107, and in order to increase the area in which the thermally conductive adhesive injected from the through holes expands, they are added to these. Two through holes are formed. By setting the arrangement of the through holes to m rows and n columns, it is possible to configure an efficient heat dissipation path from the rectangular image sensor 101 and the image sensor substrate 102 serving as a heat source. In addition, the efficiency of the heat radiation path can be further improved by adding through holes to the periphery and inside of the m rows and n columns of through holes as in this embodiment. For example, it is also possible to increase the density of the heat radiation path by the heat conductive adhesive by forming a through hole in a staggered arrangement by adding a through hole to the inside with respect to the through hole of m rows and n columns.

  FIG. 5 is a cross-sectional view taken along the line AA of FIG. 4 showing the flow of the heat conductive adhesive 113 injected from the through hole 107a. FIG. 5B is a partially enlarged view of the flow of the heat conductive adhesive 113 taken along the line AA in FIG.

  When the heat conductive adhesive 113 in the liquid state is continuously injected from the through hole 107a, the through hole 107a is filled so as to fill a space between the heat radiating metal plate 103 of the image sensor unit 104 and the flat portion 107a of the main frame 107. It spreads concentrically as the center. In the surface of the heat radiating metal plate 103 of the image pickup device unit 104, the portion where the heat conductive clay 109 is attached to make this surface flat is sandwiched between the flat portion 107a of the main frame 107 and the heat conductive clay 109. The thermally conductive adhesive 113 is injected so that the filled space is filled. Since the thermally conductive adhesive 113 is injected in a liquid state, it does not affect the position of the image sensor unit 104 that has already been adjusted in the flange back in the first step. Further, it is not necessary to prepare and assemble a special member in order to thermally connect the distance between the image sensor unit 104 and the main frame 107 which are different for each camera body.

  When the diameter of the thermally conductive adhesive 113 injected from each through hole 107b increases to a distance corresponding to the distance between adjacent through holes 107b, the thermally conductive adhesive 113 injected from each through hole 107b becomes The heat dissipation metal plate 103 of the image sensor unit 104 and the flat portion 107a of the main frame 107 are configured to be thermally connected together.

  The heat conductive adhesive 113 is cured by reacting with moisture contained in the air or the member by leaving it after the injection is completed. The method of curing the heat conductive adhesive is not limited to this, and includes those by drying and those by ultraviolet irradiation.

  Next, the relationship between the diameters and intervals of the through holes 107b formed in the flat portion 107a of the main frame 107 will be described.

  FIG. 6 is a schematic diagram relating to the arrangement of m rows and n columns of through holes 107 b formed in the planar portion of the main frame 107. The schematic diagram of FIG. 6 shows an arrangement of through holes 107b of 2 rows and 2 columns for ease of explanation. In FIG. 6, the diameter of the through hole 107b is r, and the interval is l.

  The heat conductive adhesive 113 spreads concentrically so as to fill a space sandwiched between the heat radiating metal plate 103 of the imaging element unit 104 and the flat portion 107a of the main frame 107 with the through hole 107b as the center. The range in which the thermally conductive adhesive 113 spreads is determined by the injection time and speed.

  When filling the space between the heat radiating metal plate 103 of the image sensor unit 104 and the flat portion 107a of the main frame 107 with the heat conductive adhesive 113, the heat transfer efficiency is increased by maximizing the cross-sectional area of the heat radiating path as much as possible. It is preferable to fill as described above. For that purpose, it is preferable that the heat conductive adhesive 113 spreads concentrically up to half of the distance between the through holes 107b adjacent to each other diagonally at the maximum.

  On the other hand, in this case, there is a possibility that the heat conductive adhesive 113 injected from the through hole 107b flows backward from the adjacent through hole 107b and leaks to an unnecessary part inside the camera body. It is necessary to set the diameter r and the interval l to appropriate ranges. More specifically, in the through hole 107b of m rows and n columns, the distance between the through holes 107b diagonally adjacent to each other is ½ of the through hole 107b into which the heat conductive adhesive 113 is injected. It is necessary to make it shorter than the shortest distance among the distances from the center to the peripheral edge of the adjacent through hole 107b.

The above conditions can be expressed as follows.
√2 × l / 2 <l−r / 2
That is,
r <(2-√2) × l
However,
r: Diameter of the through hole l: Shortest distance among the distances between the through holes adjacent in the vertical direction or the horizontal direction

  By setting the diameter r and the interval l of the through holes 107b to appropriate ranges in the m rows and n columns of the through holes 107b formed in the flat surface portion 107a of the main frame 107, the unnecessary inside of the camera body is unnecessary. The heat conductive adhesive 113 does not leak into the portion, and the image sensor unit 104 and the main frame 107 can be thermally connected with a wider cross-sectional area.

  According to the present invention, an image sensor unit including an image sensor and an image sensor substrate serving as a heat source even if there is an individual difference in the adjusted flange back without affecting the adjusted flange back, and the main frame are more widely disconnected. It is possible to provide an imaging apparatus having a heat dissipation structure that can be reliably thermally connected with an area, and a method for manufacturing the imaging apparatus.

DESCRIPTION OF SYMBOLS 100 Camera body 101 Image pick-up element 102 Image pick-up element board 103 Heat sink metal plate 104 Image pick-up element unit 105 Front cover 105a Boss 106 Lens mount 106a Mount surface 107 Main frame 107a Plane part 107b Through-hole 108 Image pick-up element base 109 Thermally conductive clay 110 Washer 111 Screw 112 Screw 113 Thermally conductive adhesive

Claims (4)

In an imaging device that obtains a captured image by imaging subject light on an imaging device by a lens optical system,
An imaging element unit comprising an imaging element, an imaging element substrate for mounting the imaging element, and a heat dissipating metal plate for fixing the imaging element substrate;
A front cover having a lens mount for mounting a lens optical system and fixing the image sensor unit;
A main frame which fixes the front cover and has a through hole of m rows and n columns formed at a position overlapping the image sensor unit when viewed from the optical axis direction of the image sensor;
An image pickup apparatus, wherein a space between the main frame and the heat radiating metal plate is filled with a heat conductive adhesive around a through hole formed in the main frame.   The imaging apparatus according to claim 1, wherein thermally conductive clay is attached to the heat radiating metal plate between the heat radiating metal plate and the main frame. The imaging apparatus according to claim 1, wherein the through holes of m rows and n columns formed in the main frame satisfy the following condition.
r <(2-√2) × l
However,
r: Diameter of the through hole l: Shortest distance among the distances between the through holes adjacent in the vertical direction or the horizontal direction An imaging element unit comprising an imaging element, an imaging element substrate for mounting the imaging element, and a heat dissipating metal plate for fixing the imaging element substrate;
A front cover having a lens mount for mounting a lens optical system and fixing the image sensor unit;
Subject light is applied to the image sensor by a lens optical system having a main frame in which a through-hole of m rows and n columns is formed at a position overlapping the image sensor unit when viewed from the optical axis direction of the image sensor. A method of manufacturing an imaging device that acquires a captured image by forming an image,
A first step of adjusting a flange back when fixing the imaging element unit to the front cover;
A second step of fixing the front cover to the main frame;
Thermally conductive adhesive is filled between the main frame and the heat dissipation metal plate around the through hole formed in the main frame from the m row and n column through hole formed in the main frame. A method for manufacturing an imaging device, comprising a third step of injecting.

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