JP2007121848A - Imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device which saves the trouble at assembling, and decreases the number of components and can be improved in reliability. <P>SOLUTION: In the imaging device, a large cylindrical member 22A and a small cylindrical member 22B, made of conductive resin are insulated by an insulating member 22C, connected to the plus terminal and minus the terminal of a coil 33 respectively, and used for power supply so that lead wires are not needed to be specially provided, to save the trouble for assembling and decreasing the number of components, and further avoid troubles such as breaking of wires. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging apparatus, and more particularly to an imaging apparatus suitable for use in an imaging apparatus using a solid-state imaging device such as a CCD image sensor or a CMOS image sensor.

  2. Description of the Related Art In recent years, an image pickup apparatus equipped with an autofocus mechanism (hereinafter referred to as an AF mechanism) is mounted along with improvement in performance of an image pickup apparatus using a charge coupled device (CCD) type or a complementary metal oxide semiconductor (CMOS) type solid-state image pickup device. Mobile phones are becoming popular.

Patent Document 1 discloses a lens driving device in which an actuator is disposed around a lens and the lens can be driven in the optical axis direction.
JP 2004-280031 A

  By the way, in the lens driving device described in Patent Document 1, one lead wire of the coil of the actuator extends along the inner peripheral surface of the carrier, and is soldered to a metal spring on the upper portion thereof. The other lead wire extends along the bottom surface of the carrier and is soldered to a metal spring below the carrier wire. However, by arranging the lead wires on the carrier in this way, there is a problem that the labor and the number of parts at the time of assembling increase, and there is a possibility of causing problems such as disconnection.

  The present invention has been made in view of the problems of the related art, and an object of the present invention is to provide an imaging apparatus capable of reducing the labor and the number of parts at the time of assembly and improving the reliability.

An imaging apparatus according to claim 1 is provided.
A housing,
An imaging lens including at least one movable lens movable in the optical axis direction with respect to the housing;
A lens frame having conductivity at least in part and supporting the movable lens;
An actuator for moving the movable lens, wherein power is supplied to the actuator through the lens frame.

  According to the present invention, since electric power is supplied to the actuator through the lens frame having conductivity, it is not necessary to feed a lead wire to the lens frame, and the labor and the number of parts during assembly are reduced. In addition, problems such as disconnection can be avoided. In addition, a lens frame having at least a part of conductivity means that a part or all of the lens frame is a conductor (for example, conductive plastic: a product name “Sustec” marketed by JFE Techno-Research Corporation as an example). And coating / coating a conductive material on part or all of the lens frame. Further, the lens frame may be connected only to the minus terminal or the plus terminal of the actuator.

  According to a second aspect of the present invention, in the invention of the first aspect, the lens frame and the housing are connected by a metal spring member, and electric power is supplied to the actuator via the spring member. It is characterized by being supplied.

  According to a third aspect of the present invention, in the invention of the first or second aspect, the lens frame includes two conductive parts that are insulated from each other, and one of the parts is connected to a negative terminal of the actuator. The other component is connected to the positive terminal of the actuator. These two parts are preferably insulated from each other. Insulation can be performed by interposing an insulating material between the two parts, and coating / coating an insulating film on at least one of the two parts, but is not limited thereto.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the actuator is a voice coil motor having a coil attached to the lens frame, a magnet, and a yoke. It is characterized by that.

  According to the present invention, it is possible to provide an imaging device capable of reducing the labor and the number of parts during assembly and improving the reliability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an image pickup apparatus 50 including the image pickup apparatus according to the present embodiment. FIG. 2 is a cross-sectional view of the image pickup apparatus 50 shown in FIG. FIG.

  The imaging apparatus 50 includes a CMOS image sensor 51 as a solid-state imaging device having a photoelectric conversion unit 51a, an imaging lens 10 as an imaging lens that causes the photoelectric conversion unit 51a of the image sensor 51 to capture a subject image, and an image sensor. IR cut filter F disposed between 51 and imaging lens 10, substrate 52 having external connection terminal 54 (FIG. 1) for holding image sensor 51 and transmitting and receiving electrical signals, and imaging lens An assembly housing 20 to be supported and an actuator (also referred to as a focus actuator) 30 for driving a focusing lens are provided, and these are integrally formed. The height Δ in the optical axis direction of the imaging apparatus 50 is 10 mm or less.

  In the image sensor 51, a photoelectric conversion unit 51a as a light receiving unit in which pixels (photoelectric conversion elements) are two-dimensionally arranged is formed in the center of a plane on the light receiving side. A processing circuit (not shown) is formed. Such a signal processing circuit includes a drive circuit unit that sequentially drives each pixel to obtain a signal charge, an A / D conversion unit that converts each signal charge into a digital signal, and a signal that forms an image signal output using the digital signal. It consists of a processing unit and the like. A number of pads (not shown) are arranged near the outer edge of the plane on the light receiving side of the image sensor 51, and are connected to the substrate 52 via wires W. The image sensor 51 converts the signal charge from the photoelectric conversion unit 51 a into an image signal such as a digital YUV signal, and outputs the image signal to a predetermined circuit on the substrate 52 via the wire W. Here, Y is a luminance signal, U (= R−Y) is a color difference signal between red and the luminance signal, and V (= BY) is a color difference signal between blue and the luminance signal. Note that the image sensor is not limited to the above CMOS image sensor, and other devices such as a CCD may be used.

  The substrate 52 includes a support flat plate 52a that supports the image sensor 51 and the outer cylinder 21 on one plane, and a flexible substrate 52b (FIG. 1) having one end connected to the support flat plate 52a.

  The support flat plate 52a has a large number of signal transmission pads provided on the surface thereof, which are connected to the wires W from the image sensor 51 described above and to the flexible substrate 52b.

  As described above, one end of the flexible substrate 52b is connected to the support flat plate 52a, and the support flat plate 52a and an external circuit (for example, a host device on which an imaging device is mounted) are connected via an external connection terminal 54 provided at the other end. Control circuit), and a voltage and a clock signal for driving the image sensor 51 are supplied from an external circuit, and a digital YUV signal can be output to the external circuit. Furthermore, the intermediate portion in the longitudinal direction of the flexible substrate 52b is flexible or easily deformable, and the deformation gives freedom to the orientation and arrangement of the external output terminals with respect to the support flat plate 52a.

  An assembly housing 20 made of a light-shielding member is disposed so as to surround the image sensor 51, and is attached to a lower cylinder 21A in which a lower end is bonded to the substrate 52 using an adhesive B and an upper part of the lower cylinder 21A. The outer cylinder 21 including the short cylinder-shaped upper cylinder 21B is included.

  In FIG. 2, an IR cut filter F is attached to a flange portion 21a extending from the inner periphery of the lower cylinder 21A in the direction perpendicular to the optical axis.

  A movable cylinder (also referred to as a lens frame) 22 movably arranged with respect to the assembly housing 20 includes a large cylindrical member 22A made of a conductive resin and a small cylindrical member 22B made of a conductive resin arranged on the upper part thereof. And an insulating material 22C disposed between the large cylindrical member 22A and the small cylindrical member 22B, and a holding member 22D made of a conductive resin disposed below the large cylindrical member 22A. A small flange portion 22a is formed at the upper end of the small cylindrical member 22B, and the central opening is an aperture stop S.

  The movable cylinder 22 holds the fixed lens in the order of the first lens L1, the second lens L2, and the third lens L3 from the object side. A stopper SP is provided on the upper surface of the flange portion 21a of the lower cylinder 21A, and movement of the movable cylinder 22 is restricted by contacting the holding member 22D.

  The flange portion L1f of the first lens L1 is abutted and fitted so as to include the upper portion of the flange portion L2f of the second lens L2. Further, the flange portion L3f of the third lens L3 is abutted and fitted so as to contain the lower portion of the flange portion L2f of the second lens L2. The outer diameters of the first lens L1 and the second lens L2 are slightly smaller than the outer diameter of the third lens L3. Therefore, when the lenses L1 to L3 are assembled in the small cylindrical member 22B in the manner described later, the optical axis of the lens with respect to the movable cylinder 22 is the inner peripheral surface of the small cylindrical member 22B and the outer diameter of the third lens L3. The optical axis of the third lens L3 and the optical axes of the first lens L1 and the second lens L2 are accurately positioned by the fitting between the flange portions by fitting.

  On the other hand, since the flange portion L4f of the fourth lens L4 that is the most image side lens is abutted and fitted so as to be contained in the flange portion L3f of the third lens L3, the fourth lens L4 with respect to the moving cylinder 22 is thereby fitted. The optical axis can be accurately positioned. The holding member 22D is attached to the lower surface of the flange portion L4f of the fourth lens L4. The large cylindrical member 22A and the holding member 22D are bonded to each other by the conductive adhesive EB. When the non-conductive adhesive is used for bonding, the metal piece is bonded to the large cylindrical member 22A and the holding member. It is preferable to extend over 22D.

  A cylindrical actuator 30 is disposed outside the small cylindrical member 22B of the moving cylinder 22 in the direction perpendicular to the optical axis. The actuator 30 is bonded to the upper end of the large cylindrical member 22A of the movable cylinder 22, extends in the optical axis direction, and is wound around the optical axis in the circumferential direction. A magnet 32 arranged in a cylindrical shape so as to enclose the coil 33 at the upper side, and a cylinder that supports the magnet 32 and has a lower end attached to the upper cylinder 21B so as to cover from the upper side to the inner periphery of the coil 33. The yoke 31 is formed into a shape.

  The spring member 27 having a shape in which donut discs having different diameters are connected to each other by shifting the phase of the connection position is fixed to the vicinity of the lower end of the upper cylindrical portion 21B, and the inner periphery side is fixed to the lower surface of the holding member 22D. It is fixed. On the other hand, a spring member 28 having a shape similar to that of the spring member 27 has its outer peripheral side fixed to the upper surface of the yoke 31 and its inner peripheral side fixed to the upper end of the movable cylinder 22. The spring members 27 and 28 generate an urging force in response to the movement cylinder 22 moving in the optical axis direction.

  The plus terminal of the coil 33 of the actuator 30 is in contact with the surface of the large cylindrical member 22A of the movable cylinder 22, and the large cylindrical member 22A, the adhesive EB, and the holding member 22D are in contact with each other and have conductivity. The one end of the spring member 27 that comes into contact with the holding member 22D and the plus terminal of the coil 33 are conductively coupled. Further, the other end of the spring member 27 is connected to the substrate 52 through H + that penetrates the outer wall of the upper cylinder 21B and extends the outer wall of the lower cylinder 21A.

  Further, the negative terminal of the coil 33 is provided via a convex portion 22b (insulated from the large cylindrical portion 22A by the insulating material 21C) formed on the outer periphery of the lower end of the small cylindrical member 22B of the movable cylinder 22 having conductivity. Therefore, one end of the spring member 28 that contacts the small cylindrical member 22B and the negative terminal of the coil 33 are electrically coupled. Further, the spring member 28 is connected to the substrate 52 via H- extending the outer wall of the yoke 31, the upper cylinder 21B, and the lower cylinder 21A. The principle of driving the voice coil motor is well known and will be omitted. However, due to the magnetic force generated by supplying electric power to the coil 33 from the outside via the wirings H +, H−, the spring members 27 and 28 and the movable cylinder 22. The coil 33 can be displaced with respect to the magnet 32 according to the supplied electric power.

  The imaging lens 10 has, in order from the object side, an aperture stop S, a first lens L1 having a positive refractive power and a convex surface facing the object side, a second lens L2 having a negative refractive power, and a positive refractive power. The third lens L3 and the fourth lens L4 having negative refractive power are included. In the present embodiment, the lenses L1, L2, L3, and L4 constitute a focusing lens (also referred to as a movable lens). However, since the outer diameters of the lenses L1 to L3 are smaller than those of the lens L4, the outer diameters thereof. The large actuator 30 can be mounted using the difference.

  The imaging lens 10 is used to form a subject image on a solid-state imaging device using the aperture stop S and the lenses L1, L2, L3, and L4 as an optical system. The aperture stop S is a member that determines the F number of the entire imaging lens system.

  The IR cut filter F held by the flange portion 21a of the outer cylinder 21 between the imaging lens 10 and the image sensor 51 is a member formed in, for example, a substantially rectangular shape or a circular shape.

  Further, a light shielding mask SM is disposed between the first lens L1 and the second lens L2, between the second lens L2 and the third lens L3, and between the third lens L3 and the fourth lens L4. Thus, it is possible to prevent unnecessary light from entering the outside of the effective lens diameter close to the solid-state imaging device, and to suppress the occurrence of ghost and flare.

  A usage mode of the imaging apparatus 50 described above will be described. FIG. 3 is a diagram illustrating a state in which the imaging device 50 is installed in a mobile phone 100 as a mobile terminal. FIG. 4 is a control block diagram of the mobile phone 100.

  In the imaging device 50, for example, the object-side end surface of the outer cylinder 21 in the imaging lens is provided on the back surface of the mobile phone 100 (the liquid crystal display unit side is the front surface), and is arranged at a position corresponding to the lower side of the liquid crystal display unit. Established.

  The external connection terminal 54 of the imaging device 50 is connected to the control unit 101 of the mobile phone 100 and outputs an image signal such as a luminance signal or a color difference signal to the control unit 101 side.

  On the other hand, as shown in FIG. 4, the mobile phone 100 controls each unit in an integrated manner, and also supports a control unit (CPU) 101 that executes a program corresponding to each process, and inputs a number and the like with keys. An input unit 60, a display unit 70 for displaying captured images and videos in addition to predetermined data, a wireless communication unit 80 for realizing various information communication with an external server, and a mobile phone 100 By a storage unit (ROM) 91 that stores necessary data such as system programs, various processing programs, and terminal IDs, and various processing programs and data executed by the control unit 101, or processing data, or the imaging device 50 And a temporary storage unit (RAM) 92 that is used as a work area for temporarily storing imaging data and the like.

  When the photographer holding the mobile phone 100 directs the optical axis of the imaging lens 10 of the imaging device 50 toward the subject, an image signal is captured by the image sensor 51. For example, by performing image plane AF processing or the like, The focus shift can be detected. Since the control unit 101 supplies power to the actuator 30 so as to drive the lenses L1 to L4 in a direction to eliminate this defocus, the wirings H +, H− and the lens tube 22 are larger than the external connection terminal 54. Electric power is supplied to the coil 33 through the cylindrical member 22A and the small cylindrical member 22B. Since the generated magnetic force and the biasing force of the deformed spring members 27 and 28 are balanced, the lenses L1 to L4 can be moved and held together with the movable barrel 22 to the optimum focusing position. Autofocus operation can be realized. If the driving force of the actuator 30 disappears due to the interruption of the power supply, the movable cylinder 22 returns to the original position.

  When the photographer presses the button BT shown in FIG. 3 at a desired photo opportunity, release is performed, and the image signal is taken into the imaging device 50. The image signal input from the imaging device 50 is transmitted to the control system of the mobile phone 100 and stored in the storage unit 92 or displayed on the display unit 70, and further, video information is transmitted via the wireless communication unit 80. Will be transmitted to the outside.

  According to the present embodiment, the large cylindrical member 22A and the small cylindrical member 22B formed of conductive resin are insulated by the insulating member 22C, and connected to the positive terminal and the negative terminal of the coil 33, respectively. Therefore, it is not necessary to provide a lead wire separately, and it is possible to reduce labor and the number of parts at the time of assembling and avoid problems such as disconnection.

  FIG. 5 is a perspective view of a movable cylinder 22 'according to a modification of the present embodiment. In the present embodiment, the moving cylinder 22 ′ having the same shape as the above-described embodiment includes a half 22A ′ formed from a conductive resin and a half 22B ′ formed from a conductive resin. The insulating material 22C ′ is bonded to each other, but they can be formed at the same time with an insulating material interposed by two-color molding or the like. The positive terminal of the coil 33 (FIG. 2) of the actuator 30 is connected to the half part 22A ′, the negative terminal of the coil 33 is connected to the half part 22B ′, and power is supplied from the outside through these half parts 22A ′ and 22B ′. The actuator 30 can be operated by supplying.

  The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate. For example, the movable lens may be any one or more of the lenses L1 to L4, and the total number of lenses is not limited to four.

It is a perspective view of the imaging device 50 concerning this Embodiment. It is the figure which cut | disconnected the imaging device 50 of FIG. 1 by the surface containing an II-II line | wire, and looked at the arrow direction. It is a figure which shows the state equipped with the imaging device 50 in the mobile telephone 100 as a portable terminal. 3 is a control block diagram of the mobile phone 100. FIG. It is a perspective view of movable cylinder 22 'concerning the modification of this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Imaging lens 20 Assembly housing | casing 21 Outer cylinder 21A Lower cylinder 21B Upper cylinder 21a Flange part 21b Recessed part 22 Moving cylinder 22A Large cylindrical member 22B Small cylindrical member 22C Insulating member 22D Holding member 22a Small flange part 22b Convex part 27 Spring member 28 Spring Member 30 Actuator 31 Yoke 32 Magnet 33 Coil 50 Imaging device 51 Image sensor 51a Photoelectric conversion unit 52 Substrate 54 External connection terminal 60 Input unit 70 Display unit 80 Wireless communication unit 92 Storage unit 100 Mobile phone 101 Control unit EB Conductive adhesive B Adhesive BT Button F Cut filter H +, H- Wiring L1-L4 Lens S Aperture stop SP Stopper W Wire

Claims (4)

A housing,
An imaging lens including at least one movable lens movable in the optical axis direction with respect to the housing;
A lens frame having conductivity at least in part and supporting the movable lens;
And an actuator for moving the movable lens, wherein power is supplied to the actuator through the lens frame.   The imaging apparatus according to claim 1, wherein the lens frame and the housing are connected by a metal spring member, and electric power is supplied to the actuator via the spring member.   The lens frame includes two conductive parts that are insulated from each other, one part being connected to a minus side terminal of the actuator, and the other part being connected to a plus side terminal of the actuator. The imaging apparatus according to claim 1 or 2. The imaging apparatus according to claim 1, wherein the actuator is a voice coil motor having a coil attached to the lens frame, a magnet, and a yoke.

Images