JP2007150988A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus with a compact configuration and mounted with an actuator capable of driving a lens. <P>SOLUTION: The dimension of the imaging apparatus 50 can be suppressed by arranging a driver circuit 40 whose profile is comparatively thin along an outer surface (side face) of a lower cylinder 21A for configuring a housing. Further, since the driver circuit 40 and a support flat plate 52a are electrically connected by a flexible board 41, even when the driver circuit 40 is arranged at an optional position along the outer surface of the lower cylinder 21A, the support flat plate 52a can supply power to the driver circuit 40 via the flexible board 41. <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) has been mounted along with the improvement in performance of an image pickup apparatus using a CCD (Charge Coupled Device) type or CMOS (Complementary Metal Oxide Semiconductor) type solid state image pickup device. Mobile phones are becoming popular. An example of such an imaging apparatus is shown in Non-Patent Document 1.
Hidemura Nishimura, 6 others "1 / 2.7 type 2 megapixel camera module LZOP3731 with autofocus function", April 2004, Sharp Technical Report, [searched on November 25, 2005], <URL: www .sharp.co.jp / corporate / rd / 23 / pdf / 88-18.pdf>

  By the way, an actuator is required to move one or a plurality of lenses in the optical axis direction. Here, in the case of a general voice coil motor or the like, a steady current is given through a driver circuit. Such a driver circuit is often provided, for example, around or on the back surface of a substrate on which an image sensor is arranged. However, since the driver circuit is relatively large, there is a problem in that the outer shape of the imaging device becomes large if it is provided around the substrate on which the imaging element is arranged or on the back surface.

  The present invention has been made in view of the problems of the prior art, and an object thereof is to provide an imaging apparatus having a compact configuration and equipped with an actuator capable of driving a lens.

An imaging apparatus according to claim 1 is provided.
An image sensor disposed on a substrate;
A housing disposed around the image sensor;
A photographic lens including at least one movable lens movable in the optical axis direction with respect to the housing;
An actuator for moving the movable lens;
A drive circuit for driving the actuator,
The driving circuit is arranged along an outer surface of the housing, and the driving circuit and the substrate are connected by a flexible substrate.

  According to the present invention, since the driving circuit such as a driver circuit is relatively thin, the size of the entire imaging apparatus can be suppressed by arranging the driving circuit along the outer surface of the casing. In addition, since the driving circuit and the substrate are connected by a flexible substrate, the driving circuit and the substrate can also be arranged from the substrate side when the driving circuit is disposed at an arbitrary position along the outer surface of the housing. Electric power can be supplied through the flexible substrate. The “drive circuit” means a circuit for driving the actuator, and is not necessarily limited to the driver circuit.

  The imaging device according to claim 2 is characterized in that, in the invention according to claim 1, the driving circuit is disposed in a recess formed in a side surface of the casing. The dimension in the direction perpendicular to the optical axis can be suppressed while maintaining the dimension in the height direction, which is a problem when the apparatus is mounted on a mobile phone or the like.

  According to a third aspect of the present invention, in the invention of the first or second aspect, the wiring for supplying electric power to the actuator is connected to the flexible substrate. Simplify.

  The imaging device according to claim 4 is characterized in that, in the invention according to any one of claims 1 to 3, a support member is disposed outside the flexible substrate, so that the rigidity of the flexible substrate is ensured. And protection can be achieved.

  The imaging device according to claim 5 is the imaging device according to any one of claims 1 to 4, wherein the substrate and the imaging are taken by a wire straddling each side of the imaging element when viewed in the optical axis direction. Since electrical connection is made between the elements, and the drive circuit is arranged along the outer surface of the housing close to the side having the smallest number of wires, Interference between the wire and the driving circuit can be avoided. Note that the “smallest number” includes zero.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the imaging device which has a compact structure and mounts the actuator which can drive a lens.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an imaging device 50 including the imaging device according to the present embodiment, and FIG. 2 is a diagram of the imaging device 50 of FIG. 1 viewed in a direction indicated by an arrow II. The metal plate 43 is deleted (drawn with a dashed line). 3 is a view of the configuration of FIG. 2 cut along arrow III-III and viewed in the direction of the arrow. FIG. 4 is a view of the configuration of FIG. 2 cut along arrow IV-IV and viewed in the direction of the arrow. FIG.

  In FIG. 4, the imaging device 50 includes a CMOS image sensor 51 as a solid-state imaging device having a photoelectric conversion unit 51a, and 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 IR cut filter F disposed between the image sensor 51 and the imaging lens 10, and a substrate 52 having an external connection terminal 54 (FIG. 1) that holds the image sensor 51 and transmits and receives electrical signals thereof. An assembly housing 20 that supports the imaging lens and an actuator (also referred to as a focus actuator) 30 that drives the focusing lens 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 shown in FIG. 3, the image sensor 51 has a rectangular shape when viewed from the optical axis direction, and the wires W are arranged so as to straddle the respective sides. The wires W are not arranged on the side (the number of wires W = 0), and the recesses 21b and 21c (described later) are provided on the outer wall of the lower cylinder 21A closest to the side. Is avoided.

  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.

  The assembly housing 20 made of a light-shielding member is disposed so as to surround the image sensor 51, and the cross section in the direction perpendicular to the optical axis formed by adhering the lower end to the substrate 52 using the adhesive B is substantially rectangular. It includes an outer cylinder 21 including a cylinder 21A and an upper cylinder 21B that is also rectangular and attached to the upper part of the lower cylinder 21A.

  As shown in FIG. 3, the lower cylinder 21A has a substantially rectangular cross section in the direction perpendicular to the optical axis, but is not a complete rectangular shape, but has a shape in which one side surface (the lower side surface in FIG. 3) is stepped. Have. Here, the first-stage depression is 21b, and the second-stage depression in the center is 21c. The lower portions of the recesses 21b and 21c bonded to the support flat plate 52a are open, but the upper portion is shielded by the upper wall 21d (see FIG. 4). Thus, a rectangular plate-like driver circuit 40 extends along the bottom surface of the recess 21c (the outer surface of the lower cylinder 21A) in the recess 21c that is isolated so that external light and foreign matter do not enter the assembly housing 20. Are arranged. However, the upper wall 21d is not necessarily provided. The driver circuit 40 for driving the actuator 30 may be bonded to the recess 21c. However, for example, a pair of claw portions may be provided in the recess 21c so that the opposite side surfaces can be gripped.

  As shown in FIG. 4, the flexible substrate 41 having one end electrically connected to the support flat plate 52a is bent into an L shape and mounted in the recess 21b. In this state, the electrical terminals of the driver circuit 40 are electrically connected to the terminal portion on the back surface side of the flexible substrate 41 by the ball solder 42. Further, on the surface side of the flexible substrate 41, a plus terminal portion 41+ and a minus terminal portion 41- for supplying a current from the drive circuit 40 to the actuator 30 are provided apart from the metal plate 43 ( (See FIG. 2). As shown in FIG. 3, when viewed in the optical axis direction, the driver circuit 40 is disposed closer to the optical axis with respect to a straight line connecting the two corners of the lower cylinder 21A adjacent to the driver circuit 40. For example, it may be provided at a corner of the assembly housing 20.

  Furthermore, one end of a metal plate 43 such as iron is fixed to the lower cylinder 21A. The metal plate 43 serving as a support member is mounted on the outside of the flexible substrate 41 so as to cover the recess 21b while being bent in an L shape similarly to the metal plate 43. The metal plate 43 has a function of maintaining the L-shaped shape of the flexible substrate 41 that is easily bent, and the flexible substrate 41 and the driver circuit when the imaging device 50 is inadvertently brought into contact with surrounding components during assembly. 40 for protection. The metal plate 43 and the flexible substrate 41 may be bonded at least partially, but are insulated from each other.

In FIG. 4, an IR cut filter F is attached to a flange portion 21a extending in the direction perpendicular to the optical axis from the inner periphery of the lower cylinder 21A.

  The movable cylinder 22 arranged so as to be movable with respect to the assembly housing 20 includes a large cylindrical portion 22a, a small cylindrical portion 22b connected to the upper end thereof, a small flange portion 22c formed on the upper end thereof, and a large cylinder. The first lens L1 and the second lens from the object side have a large flange portion 22d that connects the portion 22a and the small cylindrical portion 22b, and a holding member 22e that is bonded so as to close the lower end of the large cylindrical portion 22a. These are fixedly held in the order of L2, third lens L3, and fourth lens L4. A central opening of the small flange portion 22c is an aperture stop S.

  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 having different outer diameters between the upper portion and the lower portion is abutted and fitted so that the upper portion includes 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 smaller than the outer diameter of the third lens L3. Therefore, when the lenses L1 to L3 are assembled in the moving cylinder 22 so that the first lens L1 faces the large flange portion 22d, the optical axis of the lens (and the relative position in the optical axis direction) with respect to the moving cylinder 22 is It is positioned with high accuracy by abutting fitting between the inner peripheral surface of the small cylindrical portion 22b and the upper outer diameter of the flange portion L3f of the third lens L3, and by fitting between the flange portions, the optical axis of the third lens L3, The optical axes of the first lens L1 and the second lens L2 are accurately positioned.

  On the other hand, the flange portion L4f of the fourth lens L4, which is the most image side lens, is abutted and fitted so as to be included in the lower portion of the flange portion L3f of the third lens L3. The optical axis of the fourth lens L4 can be accurately positioned. The holding member 22e is attached to the lower surface of the flange portion L4f of the fourth lens L4. Not limited to the above example, the lenses L1 to L4 may be accommodated in a lens tube having the same outer diameter, and the actuator may be disposed on the outer side.

  A cylindrical actuator 30 is disposed outside the lenses L1 to L3 perpendicular to the optical axis. The actuator 30 is attached to the upper end of the large cylindrical portion 22a and extends in the optical axis direction. The actuator 30 supports the magnet 32 and the magnet 32 disposed so as to contain the coil 33 above the upper cylinder 21B. The yoke 31 has a lower end attached to the upper tube 21B so as to cover the inner periphery of the coil 33. The magnet 32 may be attached to the large cylindrical portion 22a, and the coil 33 may be attached to the upper tube 21B.

  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 by sandwiching the outer peripheral side between the upper cylinder 21B and the lower cylinder 21A and holding the inner peripheral side thereof. It is fixed to the lower surface of the member 22e. On the other hand, the spring member 28 having a shape similar to 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 surface of the flange member 22c. The spring members 27 and 28 generate a biasing force in response to the lenses L1 to L4 moving integrally in the optical axis direction.

  A plus terminal of the coil 33 of the actuator 30 is connected to the spring member 27 via a wiring H1 + extending along a groove formed in the outer wall of the large cylindrical portion 22a and the holding member 22e. Furthermore, the spring member 27 is connected to one end of the wiring H2 + that passes between the upper cylinder 21B and the lower cylinder 21A and goes to the outside. The other end of the wiring H2 + is soldered to the plus terminal portion 41+ of the flexible substrate 41 in the recess 21b of the lower cylinder 21A (see FIG. 2). In the above example, the positive side wiring (H1 +, H2 +) of the actuator 30 is connected to the spring member 27, and the negative side wiring (H1-, H2-) is connected to the spring member 28. For example, the spring member 27 (or 28) is divided into two parts and insulated from each other, and the plus side wiring (H1 +, H2 +) or the minus side wiring (H1-, H2-) is provided for each of the insulated divided parts. May be connected.

  Further, the negative terminal of the coil 33 is connected to the spring member 28 via a wiring H <b> 1 that extends on the outer wall of the movable cylinder 22. Further, the spring member 28 is connected to one end of H2- extending the outer wall of the yoke 31, and the other end of the wiring H2- is soldered to the plus terminal portion 41- of the flexible substrate 41 in the recess 21b. (See FIG. 2). The driving principle of the voice coil motor is well known and will be omitted. However, the driver circuit 40 supplies power to the coil 33 via the flexible substrate 41, the wirings H2 + and H2-, the spring members 27 and 28, and the wirings H1 + and H1-. The coil 33 can be displaced with respect to the magnet 32 according to the supplied electric power by the magnetic force generated by supplying.

  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 and L2 are smaller than those of the lenses L3 and L4, A large actuator 30 can be mounted using the difference in outer diameter.

  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. Thereby, it is possible to prevent unnecessary light from entering the outside of the effective diameter of the lens L4 close to the solid-state imaging device, and to suppress the occurrence of ghost and flare.

  According to the present embodiment, the dimensions of the imaging device 50 can be suppressed by arranging the relatively thin driver circuit 40 along the outer surface (side surface) of the lower cylinder 21A constituting the housing. Further, since the driver circuit 40 and the support plate 52a are electrically connected by the flexible substrate 41, the support plate is also provided when the driver circuit 40 is disposed at an arbitrary position along the outer surface of the lower cylinder 21A. Electric power can be supplied from the 52a side through the flexible substrate 41.

  A usage mode of the imaging apparatus 50 described above will be described. FIG. 5 is a diagram illustrating a state in which the imaging device 50 is installed in a mobile phone 100 as a mobile terminal. FIG. 6 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. 6, the mobile phone 100 controls each unit in an integrated manner, and supports and inputs a control unit (CPU) 101 that executes a program corresponding to each process, and 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. The control unit 101 sends a command to the driver circuit 40 from the support flat plate 52a via the flexible board 41 so as to drive the lenses L1 to L4 in a direction to eliminate this defocus. Then, the driver circuit 40 generates a current corresponding to the command and supplies the current to the coil 33 via the wirings H1 +, H2 +, H1-, H2-. At this time, the magnetic flux density is increased by the yoke 31 arranged around the magnet 32, and the electric power can be efficiently converted into a magnetic force. 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. 5 at a desired photo opportunity, the 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.

  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 driver circuit 40 may be arranged along the upper surface (subject side surface) of the assembly housing 20. Further, instead of providing the metal plate 43, the side wall of the lower cylinder 21A may be doubled, and the driver circuit 40 may be disposed therebetween. 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 looked at the imaging device 50 of FIG. 1 in the direction shown by arrow II. It is the figure which cut | disconnected the structure of FIG. 2 by the arrow III-III line, and looked at the arrow direction. It is the figure which cut | disconnected the structure of FIG. 2 by the arrow IV-IV line, 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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Imaging lens 20 Assembling case 21 Outer cylinder 21A Lower cylinder 21B Upper cylinder 21a Flange part 21b, 21c Depression 21d Upper wall 22 Moving cylinder 22a Large cylindrical part 22b Small cylindrical part 22c Small flange part 22d Large flange part 22e Holding member 27 Spring Member 28 Spring member 30 Actuator 31 Yoke 32 Magnet 33 Coil 40 Driver circuit 41 Flexible board 41+ Positive terminal part 41- Negative terminal part 42 Ball solder 43 Metal plate 50 Imaging device 51 Image sensor 51a Photoelectric conversion part 52 Substrate 52a Support flat plate 52b Flexible Substrate 54 External connection terminal 60 Input unit 70 Display unit 80 Wireless communication unit 92 Storage unit 100 Mobile phone 101 Control unit B Adhesive BT Button F IR cut filter H1 +, H1-Wiring H2 +, H2-Wiring 1~L4 lens L1f~L4f flange portion S aperture stop SM shading mask W wire

Claims (5)

An image sensor disposed on a substrate;
A housing disposed around the image sensor;
A photographic lens including at least one movable lens movable in the optical axis direction with respect to the housing;
An actuator for moving the movable lens;
A drive circuit for driving the actuator,
The drive circuit is disposed along an outer surface of the housing, and the drive circuit and the substrate are connected by a flexible substrate.   The imaging apparatus according to claim 1, wherein the driving circuit is disposed in a recess formed in a side surface of the casing.   The imaging apparatus according to claim 1, wherein a wiring for supplying electric power to the actuator is connected to the flexible substrate.   The imaging apparatus according to claim 1, wherein a support member is disposed outside the flexible substrate. When viewed in the optical axis direction, electrical connection is made between the substrate and the image sensor by wires straddling each side of the image sensor, and it is close to the side having the smallest number of wires. The imaging device according to claim 1, wherein the driving circuit is arranged along an outer surface of the casing.

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