Patent ID: 12250799

DETAILED DESCRIPTION

An imaging device according to the present disclosure will be described with reference to the drawings described below.

First Embodiment

A configuration of an imaging device100according to a first embodiment will be described with reference toFIGS.1to5.

FIG.1is an arrangement diagram of an example of the imaging device100according to the present embodiment. The imaging device100is mounted on a moving object200, for example. The moving object200is, for example, a vehicle, a ship, an aircraft, a drone, or the like. In the present embodiment, the form in which the moving object200is a vehicle will be described as an example. A portion where the imaging device100is mounted is not limited toFIG.1, and the imaging device100may be mounted on the front, rear, and side mirrors of the vehicle, for example. In the present example, an example of the imaging device100mounted on the vehicle is described as an example, but the imaging device100is not limited to the form in which the imaging device100is mounted on the vehicle. Furthermore, the imaging device100may be installed on a non-moving object.

FIG.2is an exploded view of the example of the imaging device according to the present embodiment. The imaging device100includes a lens barrel101, a front case103, a sensor board104, sensor board fixing screws105, a waterproof packing106, a rear case107, case fixing screws108, an air hole screw109, and a shield member112.

The lens barrel101and the sensor board104are examples of imaging optical units120. The imaging optical units120include a lens, an imaging element, and the like, and obtain an image signal by imaging an image. The lens is provided on the lens barrel101, for example. The imaging element is provided on the sensor board104, for example.

The lens barrel101is attached to the outside of the front case103. The sensor board104is attached to the inside of the front case103by the sensor board fixing screws105.

The front case103is an example of a first case. The front case103supports the lens barrel101and the sensor board104that are the imaging optical units120. The front case103is an electrically conductive member.

The rear case107is an example of a second case. The rear case107has an output mechanism107A that outputs a signal output from each of the imaging optical units120. The output mechanism107A is an electrically conductive connection portion through which an electrical cable or the like outputting an image signal that is the signal output from each of the imaging optical units120is connected.

The rear case107is attached to the front case103by the case fixing screws108. As described above, the sensor board104is attached to the front case103. As a result, the sensor board104is sandwiched between the front case103and the rear case107, and is in a supported state. For the purpose of improving waterproof properties, it is preferable to adopt a configuration in which the waterproof packing106made of rubber is provided between the front case103and the rear case107. Hereinbelow a structure formed by attaching the rear case107to the front case103may be referred to as a housing110.

The shield member112electrically connects the front case103and the output mechanism107A. In the present embodiment, the shield member112is provided between the rear case107and the front case103.

Main members constituting the imaging device100is described with more details.

Lens Barrel101

The lens barrel101is attached to the front case103through an adhesive102, and is a cylindrical member into which a lens is incorporated. The lens barrel101can be formed using a resin material, for example.

The lens incorporated into the lens barrel101is made of plastic, glass, or the like. The lens is disposed along an optical axis inside the lens barrel101and images light from a subject on the imaging element of the sensor board104.

Front Case103

The lens barrel101is attached to the front case103in such a manner that the lens barrel101is attached to the outside of the front case103, that is, the lens barrel101is attached to an opposite side to a side to which the rear case107is attached. It is preferable that a hole having the same shape as that of an end surface of the lens barrel101is formed on a surface of the front case103, to which the lens barrel101is attached. By fitting one end of the lens barrel101into the hole in the front case103, the lens barrel101is attached to the front case103.

A surface that is a peripheral edge of the hole in the front case103and is a surface with which the end surface of the lens barrel101comes into contact is coated with the adhesive102for fixing the lens barrel101. The housing110is fixed to the lens barrel101with the adhesive102in a state in which a relative positional relationship between the imaging element and the lens barrel101has been adjusted.

The adhesive102has at least curing properties by heat treatment. In order to attach the front case103to the lens barrel101with higher accuracy, the adhesive102preferably has a property of being temporarily cured by, for example, ultraviolet (UV) irradiation prior to the main curing by heat treatment. Examples of the adhesive102that is cured through such two steps include adhesive containing an epoxy resin. By curing the adhesive102with the UV irradiation in advance, the lens barrel101attached to the housing110is prevented from shifting its position until the adhesive102is cured by heat treatment.

As a material of the front case103, any electrically conductive member may be adopted. The material of the front case103can be, for example, a metal such as aluminum, an electrically conductive resin, or the like.

Sensor Board104

The sensor board104is a board on which the imaging element is mounted. The imaging element is, for example, a complementary MOS (CMOS) or a charge coupled device (CCD). The imaging element receives light that has passed through the lens in the lens barrel101and converts the light into an image signal.

Holes through which the sensor board fixing screws105pass are formed on edge portions of the sensor board104. The sensor board104is fixed to the front case103by the sensor board fixing screws105through the holes thereof. For example, a metal such as stainless steel can be used as a material of the sensor board fixing screws105. The sensor board104is fixed to the front case103by the sensor board fixing screws105to be electrically connected to the front case103through the sensor board fixing screws105.

Waterproof Packing106

The waterproof packing106is a sealing member to keep an inner space of the housing110airtight. The waterproof packing106is sandwiched between the front case103and the rear case107, and is pressed from both sides. As a result, the waterproof packing106seals a mating surface of the front case103and the rear case107, and the imaging device100has a waterproof function. Any elastic material, such as rubber for example, can be used as a material of the waterproof packing106.

Rear Case107

The rear case107will be described with reference toFIGS.2,3A, and3B.FIG.3Ais a perspective view of the rear case107, which is an example viewed from the output mechanism107A side.FIG.3Bis a perspective view of an example of the rear case107, which is an example viewed from the lens barrel101side.

The rear case107includes the output mechanism107A to output an image signal. As described above, the output mechanism107A is an electrically conductive connection portion through which an electrical cable outputting an image signal that is the signal output from each of the imaging optical units120is connected. Examples of the output mechanism107A include a coaxial (2-wire type) connector, a shield twisted quad wire (STQ) (4-wire type) connector, a STQ with CAN (6-wire type) connector, and the like.

An air hole111is formed in the rear case107. The air hole111is a hole through which the inner space of the housing110and the outer space of the housing110are connected to each other. The air hole111is sealed by the air hole screw109.

The rear case107may be any member as long as the output mechanism107A of the rear case107is electrically conductive. Portions of the rear case107other than the output mechanism107A may be or may not be electrically conductive. For example, a resin or a metal can be used as a material of the portions of the rear case107other than the output mechanism107A. From the viewpoint of moldability, it is preferable to be made of a resin, and from the viewpoint of heat dissipation, it is preferable to be made of a metal. The front case103and the rear case107may be made of the same material, or each may be made of a different material.

Shield Member112

Next, a configuration and function of the shield member112will be described with reference toFIGS.2,4, and5.FIG.4is a perspective view of an example of the shield member112.FIG.5is an enlarged cross-sectional view of the housing110.

The shield member112is electrically conductive. The shield member112electrically connects the front case103and the output mechanism107A provided in the rear case107.

As illustrated inFIGS.2and4, the shield member112has a protruding shape in which the central portion protrudes in a direction away from the lens barrel101and is formed to cover the sensor board104. The shield member112includes an opening portion on which the output mechanism107A is installed.

In the present embodiment, a protruding portion113is provided at an end portion of the shield member112.FIG.4illustrates, as an example, a configuration in which two protruding portions113are provided on each of the four sides of the rectangular-shaped shield member112. That is,FIG.4illustrates, as an example, a configuration in which eight protruding portions113are provided on the shield member112.

The protruding portion113is an example of a first protruding portion. As illustrated inFIGS.4and5, each of the protruding portions113is a member that protrudes in a direction toward the front case103. The shield member112is disposed to come into contact with the front case103through the protruding portions113.

A contact resistance between the protruding portions113and the front case103may have any predetermined resistance value capable of lowering a potential of the output mechanism107A to ground (GND) through the shield member112, the protruding portions113, and the front case103. The imaging device100of the present embodiment is mounted on the moving object200to be connected to an electrically conductive site on the housing or the like of the moving object200. Therefore, the output mechanism107A is grounded through the shield member112, the protruding portions113, and the front case103. Hereinbelow the predetermined resistance value may be referred to as a predetermined value of contact resistance. The predetermined value of the contact resistance between the protruding portions113and the front case103is, for example, equal to or less than 1Ω and is preferably equal to or less than 0.5Ω.

The protruding portion113is an elastic member. A shape of each of the protruding portions113may be a shape capable of achieving the amount of deflection, the maximum stress, and the minimum contact pressure against the front case103in order to reduce the contact resistance between the front case103and the protruding portions113to the above described predetermined value.

Materials of the shield member112and the protruding portions113may be any electrically conductive materials. For example, metals such as aluminum, electrically conductive resins, and the like can be used as materials of the shield member112and the protruding portions113. The materials of the shield member112and the protruding portions113may be any materials that are electrically conductive and satisfy the Young's modulus, Poisson's ratio, and the yield strength in order to achieve the above described predetermined value of the contact resistance between the protruding portions113and the front case103.

For example, it is assumed that two types of materials, SUS304-CSP 3/4H and SUS301-CSP H, are employed as materials of the shield member112and the protruding portion113. For example, SUS304-CSP 3/4H is used for the protruding portions113with a long spring length, and SUS301-CSP H is used for the protruding portions113with a short spring length. For example, it is assumed that the Young's modulus of the shield member112and the protruding portions113is 193000 MPa and the Poisson's ratio thereof is 0.3. For example, it is assumed that the yield strength of the shield member112and the protruding portion113is 665 MPa in a case of using SUS304-CSP 3/4H, and is 1030 MPa in a case of using SUS301-CSP H. Under these conditions, in a case in which a displacement of 0.1 mm is applied to the protruding portions113, and the contact resistance between the protruding portions113and the front case103is measured, a contact pressure is equal to or more than 0.3 N that is the minimum contact pressure for SUS301-CSP H, and is stable, thereby capable of achieving the contact resistance of equal to or less than 1Ω.

FIG.4illustrates an example in which eight protruding portions113are provided on the shield member112, as an example. However, the number and positions of the protruding portions113are not limited to the example illustrated inFIG.4. For example, the protruding portions113may be configured such that one protruding portion113is provided on each of the four sides of the rectangular-shaped shield member112. Specifically, for example, the protruding portions113may be configured such that four protruding portions113are provided on the shield member112.

Shapes, materials, quality of the materials, number, positions, and the like of the shield member112and the protruding portions113are not limited to the form described above, as long as the potential of the output mechanism107A can be lowered to ground through the shield member112, the protruding portions113, and the front case103.

FIG.4illustrates an example in which the plurality of protruding portions113having the same shape as one another are provided on the shield member112, as an example. However, the shapes of the plurality of protruding portions113provided on the shield member112may be the same as one another, or at least one or more of the plurality of protruding portions113may have a shape different from other protruding portions113. For example, a configuration in which protruding portions113with a long spring length and protruding portions113with a short spring length are provided in combination on each of the four sides of the rectangular-shaped shield member112may be adopted. In addition, a configuration in which the plurality of protruding portions113with the same spring length and different widths are provided on each side of the shield member112may be adopted. Furthermore, all of the shapes of the plurality of protruding portions113provided on the shield member112may be different from each other, depending on a shape of an area in contact with the front case103.

Next, an action of the imaging device100according to the present embodiment will be described.

In the present embodiment, the shield member112is electrically conductive and electrically connects the electrically conductive front case103and the electrically conductive output mechanism107A. In detail, the shield member112includes the protruding portions113and is disposed to come into contact with the front case103through the protruding portions113.

Therefore, the front case103, the output mechanism107A of the rear case107, the shield member112, and each of the protruding portions113are electrically connected. Thus, a potential of the front case103is approximately the same as that of the output mechanism107A of the rear case107, that is, the potential of the front case103is approximately the same ground (GND) potential of the output mechanism107A. That is, the output mechanism107A of the rear case107, the shield member112, each of the protruding portions113, and the front case103are electrically connected, so that the imaging device100can have a GND-reinforced structure.

As described above, the imaging device100of the present embodiment includes the front case103, the rear case107, and the shield member112. The front case103supports the imaging optical units120. The rear case107has the output mechanism107A that is electrically conductive and outputs a signal output from each of the imaging optical units120. The shield member112electrically connects the front case103and the output mechanism107A.

Therefore, the front case103, the output mechanism107A of the rear case107, and the shield member112are electrically connected, so that the imaging device100can have the GND-reinforced structure. That is, in the imaging device100of the present embodiment, the shield member112can sufficiently function as an electromagnetic wave shield. As a result, the imaging device100of the present embodiment can improve noise immunity against noise that is electromagnetic interference (EMI) and that is generated by signals in the external environment of the imaging device100, which are output from a radio, a television, and the like.

Therefore, the imaging device100of the present embodiment can improve the noise immunity.

Since the present embodiment can improve the noise immunity, it is possible to provide the imaging device100that satisfies high performance and high noise immunity to noise.

In addition, in the imaging device100of the present embodiment, the shield member112can improve the noise immunity of the imaging device100. Therefore, the imaging device100of the present embodiment can achieve miniaturization of the imaging device100in addition to the improvement of the noise immunity.

Second Embodiment

An imaging device according to a second embodiment will be described.

In the imaging device of the present embodiment, a configuration in which a plurality of boards104C are laminated in the housing110is adopted. The boards104C are an example of an electronic board.

The imaging device of the present embodiment has the same configuration as the imaging device100of the first embodiment, except for a configuration in which the plurality of boards104C are laminated. The same numerals are given to the same members as those in the first embodiment, and detailed explanations will not be repeated.

FIG.6is a schematic diagram of an example with an enlarged portion of the boards104C of an imaging device100B according to the present embodiment.FIG.7is a perspective view of an example of a sensor-side board104A and a camera interface-side board104B.

InFIGS.6and7, the sensor-side board104A and the camera interface-side board104B are illustrated as the boards104C. The imaging device100B may have a configuration in which three or more boards104C are laminated.

The sensor-side board104A is one board104C that is fixed to the front case103through the sensor board fixing screws105(seeFIG.1). The camera interface-side board104B is one board104C that includes a mounting board connector to be fit with the output mechanism107A and is integrated with the sensor-side board104A via a flexible circuit.

Shield members114are provided between the sensor-side board104A and the camera interface-side board104B. The shield members114are an example of the second shield member. The shield members114are electrically conductive and elastic members that connect the plurality of boards104C.

The shield members114may be any members that are electrically conductive and elastic.FIG.6illustrates a configuration in which a shield member114A and a shield member114B are provided between the sensor-side board104A and the camera interface-side board104B, as an example. The shield member114A and the shield member114B are an example of the shield members114.

FIG.8is a schematic diagram of an example of the shield member114A enlarged. The shield member114A is attached to the sensor-side board104A and is an electrically conductive component consisting of three components of a pin, a tube, and a spring. An electrically conductive plating layer is provided on the pin positioned at a distal end of the shield member114A. The electrically conductive plating layer is formed of, for example, gold plating.

Return toFIG.6to continue the explanation. The electrically conductive plating layer is also provided at a position on the camera interface-side board104B where the pin of the shield member114A comes into contact (hereinafter, referred to as a “land”). According to these configurations, the sensor-side board104A and the camera interface-side board104B are electrically connected through the pin of the shield member114A, the electrically conductive plating layer, and the land of the camera interface-side board104B. The land has, for example, a size of φ1.5 mm and a thickness of 0.1 mm, but the size and the thickness of the land are not limited thereto.

The pin positioned at the distal end of the shield member114A is spring-like and has a predetermined movement range and a spring pressure. Therefore, the shield member114A is elastic.

A contact resistance between the shield member114A and each of the sensor-side board104A and the camera interface-side board104B may have any predetermined resistance value capable of lowering a potential of the output mechanism107A to ground through the shield member112, the protruding portion113, the shield member114A, the shield member114B, and the front case103. The contact resistance between the shield member114A and each of the sensor-side board104A and the camera interface-side board104B is, for example, equal to or less than 1.5Ω, preferably equal to or less than 1Ω, and even more preferably equal to or less than 0.5Ω.

The shield member114A may have any shape and material having electrical conductivity and being capable of achieving contact resistance, with each of the sensor-side board104A and the camera interface-side board104B, equal to or less than 1.5Ω. For example, the movement range of the spring-like pin of the shield member114A is 0.9 mm, and the spring pressure is 1.08 N, but the movement range and the spring pressure are not limited thereto.

The shield member114B is a component that is attached to the camera interface-side board104B to reduce electromagnetic noise. The shield member114B has a sponge core and is surrounded by an electrically conductive fabric. Therefore, the shield member114B is electrically conductive and elastic.

The shield member114B is disposed to come into contact with the sensor board fixing screws105for fixing the sensor-side board104A. The sensor board fixing screws105are electrically conductive screws. According to these configurations, the sensor-side board104A and the camera interface-side board104B are electrically connected through the shield member114B and the sensor board fixing screws105.

The shield member114B may have any compression rate, compression load, shape, and material having electrical conductivity and being capable of achieving contact resistance, with each of the sensor-side board104A and the camera interface-side board104B, equal to or less than 1.5Ω. The material of the electrically conductive fabric of the shield member114B is, for example, a Sn—Cu polyimide film, but not limited thereto. For example, the shield member114B can achieve the contact resistance of equal to or less than 1.5Ω by being installed in contact to have a compression rate of about 25% and a compression load of equal to or more than 5 N.

Next, an action of the imaging device100B of the present embodiment will be described.

In the present embodiment, the shield member112is electrically conductive and electrically connects the electrically conductive front case103and the electrically conductive output mechanism107A. In detail, the shield member112includes the protruding portions113and is disposed to come into contact with the front case103through the protruding portions113. Therefore, the front case103, the output mechanism107A of the rear case107, and the shield member112are electrically connected.

In the present embodiment, furthermore, a shield member114is provided between the plurality of boards104C. The shield members114are an example of the second shield member. The shield member114is an electrically conductive and elastic member that electrically connects the plurality of boards104C.

Therefore, the front case103, the output mechanism107A of the rear case107, the shield member112, and the plurality of boards104C are electrically connected. Specifically, the camera interface-side board104B is electrically connected to the sensor-side board104A that is fixed to the front case103through the shield member114A and the shield member114B. Thus, a potential of the front case103is approximately the same as that of the output mechanism107A of the rear case107, that is, the potential of the front case103is approximately the same ground (GND) potential of the output mechanism107A. That is, the output mechanism107A of the rear case107, the shield member112, the plurality of boards104C, and the front case103are electrically connected, so that the imaging device100B can have a GND-reinforced structure.

Therefore, the imaging device100B of the present embodiment can further improve noise immunity in addition to the effect of the first embodiment described above.

Third Embodiment

In the second embodiment, the example of using the shield member114A and the shield member114B as the shield members114was described as an example. However, the shield members114may be any electrically conductive and elastic members that electrically connect the plurality of boards104C, and are not limited to the shield member114A and the shield member114B.

FIG.9is a schematic diagram of an example of the boards104C provided in an imaging device100C according to the present embodiment. The imaging device100C of the present embodiment has the same configuration as the imaging device100of the first embodiment, except for a configuration in which the plurality of boards104C are laminated. In addition, the imaging device100C of the present embodiment has the same configuration as the imaging device100B of the second embodiment, except that the imaging device100C is provided with a shield member114different from the shield member114A and the shield member114B. Therefore, the same numerals are given to the same members as those in the above described embodiments, and detailed explanations will not be repeated.

In the present embodiment, a configuration in which a shield member114C is provided between the sensor-side board104A and the camera interface-side board104B will be described. The shield member114C is an example of the shield member114.

FIG.10is a schematic diagram of an example of the shield member114C enlarged. As illustrated inFIGS.9and10, the shield member114C is a shield member114with a shape different from the shield member114A and the shield member114B.

The shield member114C is attached to the camera interface-side board104B and is a component to strengthen the ground between the plurality of boards104C. The shield member114C is formed using, for example, phosphor bronze for a spring and is plated with a Sn reflow plating on a surface thereof. A portion where the shield member114C comes into contact with the sensor-side board104A is subjected to a metal surface treatment. According to these configurations, the sensor-side board104A and the camera interface-side board104B are electrically connected through the shield member114C.

A contact resistance between the shield member114C and each of the sensor-side board104A and the camera interface-side board104B may have any predetermined resistance value capable of lowering a potential of the output mechanism107A to ground through the shield member112, the protruding portion113, the shield member114C, and the front case103. The contact resistance between the shield member114C and each of the sensor-side board104A and the camera interface-side board104B is, for example, equal to or less than 1.5Ω, preferably equal to or less than 1Ω, and even more preferably equal to or less than 0.5Ω.

The shield member114C may have any shape and material having electrical conductivity and being capable of achieving contact resistance, with each of the sensor-side board104A and the camera interface-side board104B, equal to or less than 1.5Ω.

Next, an action of the imaging device100C of the present embodiment will be described.

In the present embodiment, the shield member112is electrically conductive and electrically connects the electrically conductive front case103and the electrically conductive output mechanism107A. In detail, the shield member112includes the protruding portions113and is disposed to come into contact with the front case103through the protruding portions113. Therefore, the front case103, the output mechanism107A of the rear case107, and the shield member112are electrically connected.

In the present embodiment, furthermore, the shield member114C is provided between the plurality of boards104C. The shield member114C is the example of the second shield member. The shield member114C is an electrically conductive and elastic member that electrically connects the plurality of boards104C.

Therefore, the front case103, the output mechanism107A of the rear case107, the shield member112, and the plurality of boards104C are electrically connected. Specifically, the camera interface-side board104B is electrically connected to the sensor-side board104A that is fixed to the front case103through the shield member114C. Thus, a potential of the front case103is approximately the same as that of the output mechanism107A of the rear case107, that is, the potential of the front case103is approximately the same GND potential of the output mechanism107A. That is, the output mechanism107A of the rear case107, the shield member112, the plurality of boards104C, and the front case103are electrically connected, so that the imaging device100C can have a GND-reinforced structure. In a case in which the front case103and the output mechanism107A of the rear case107are electrically connected directly, the shield member112may not be employed.

Therefore, the imaging device100C of the present embodiment can further improve noise immunity in addition to the effect of the first embodiment described above.

The shield members114may be any electrically conductive and elastic members that electrically connect the plurality of boards104C, and are not limited to the shield member114A, the shield member114B, and the shield member114C.

For example, a configuration in which the shield member114A, the shield member114B, and the shield member114C are provided between the plurality of boards104C may be adopted. In addition, a configuration in which the shield member114A and the shield member114C are provided between the plurality of boards104C may be adopted. In this case, a material, shape, number, position, and the like that enable the contact resistance between the boards104C and the shield members114to be equal to or less than the above predetermined value may be selected.

The imaging device according to the present disclosure can improve noise immunity.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.