JP2007174380A - Arrangement structure of camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an arrangement structure of a camera module having three components, i.e. a stepping motor, an image sensor and an ISP constituted compactly at a periphery of a module base supporting a lens holder. <P>SOLUTION: In constitution where the components of the camera module are arranged on respective surfaces of a nearly rectangular-parallelepiped block shape where the lens holder moving along an optical axis within a predetermined range is stored, the image sensor is arranged on a bottom surface as a focal plane perpendicular to the optical axis, the stepping motor in a flat shape is closely arranged on one flank of the module base, and the ISP is arranged in parallel to one surface of the module base. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a camera module arrangement structure. More specifically, the present invention relates to the mutual positional relationship occupied by a step motor, an image sensor, and an ISP, which are flat and relatively large main parts arranged around a module base.

  Recently, various ultra-small electronic camera modules intended to be incorporated in small electronic devices such as mobile phones have been developed. This module has, for example, a module base that has a function of supporting a lens holder (lens barrel) that holds the lens so as to be movable in the optical axis direction, an image sensor such as a C-MOS, and a lens that moves forward and backward for focusing. An integrated circuit called an ISP that controls the motor to be attached and an attached mechanism, image and color processing correction, and further controls the operation of peripheral hardware components for photographing. Since the main functions of the camera are integrated into a module, it is convenient to obtain a small electronic device in which the electronic camera is easily integrated.

  FIG. 7 is a side view (partially sectional view) of a conventional example. Reference numeral 1 denotes a module base, in which a lens holder 5 holding a lens 5a is supported so as to be slidable in the vertical direction (the optical axis direction of the lens). Reference numeral 3 denotes an image sensor, which is mounted on a circuit board (PC) 10 and placed at an imaging position of a lens. 4 is an ISP, which is also mounted on a PC. The ISP 4 is connected to a drive terminal of a cylindrical motor 11 that drives the image sensor 3 and the lens holder 5 on the PC 10.

  A drive mechanism for focusing the lens holder 5 in the conventional example will be described. The driving force is a cylindrical motor 11, and the motor shaft is placed thereon so as to be parallel to the circuit board PC10 (a support member is not shown). A worm 12 is attached to an output shaft protruding from the end of the motor 11, and a worm gear 13 meshing with the worm 12 is integrated with a cylindrical cam 14, and a common rotating shaft 15 of both is parallel to the sliding direction of the lens holder 5. The tip of the projection 17 protruding from the lens holder 5 is fitted in a spiral cam groove 16 dug in the cylindrical surface of the cylindrical cam 14. Accordingly, when the motor is rotated in the forward or reverse direction, the cylindrical cam 14 is driven by an angle proportional to the rotational speed, and the lens holder 5 is moved back and forth in the optical axis direction to the in-focus position. When focused, the drive is stopped by the ISP 4 which is a control circuit. The cylindrical cam 14 may be replaced with a screw, and the protrusion 17 of the lens holder 5 may be replaced with a nut screwed thereto.

Conventionally, as in this example, the image sensor 3 and the ISP 4 are arranged on the same plane on the same PC. Further, as shown in FIG. 7, the cylindrical motor generates a useless space around the cylindrical shape (oblique corner) of the motor case. Since the worm mechanism and the cylindrical cam also have an orthogonal axis, it is difficult to make a rational arrangement. Since the camera module is incorporated into the main electronic device, it is disadvantageous to arrange the related parts flatly or to have a cylindrical motor. The camera module is in close contact with the main module base. A compact arrangement is preferable because it is easy to reduce the size including the base unit, but the conventional structure does not satisfy this condition.

  An object of the present invention is to provide a camera module arrangement structure in which a step motor, an image sensor, and an ISP are compactly configured around a module base that supports a lens holder. A further object is to obtain a compact electronic device (master) that is easy to use and thereby compact.

In order to achieve the above object, the camera module arrangement structure of the present invention has the following features.
(1) In a configuration in which parts of a camera module are arranged on each surface of a substantially block-shaped module base containing a lens holder that moves within a predetermined range along the optical axis, a focus perpendicular to the optical axis An image sensor is disposed on the bottom surface, a flat step motor is closely disposed on one of the side surfaces of the module base, and an ISP is disposed in parallel with one of the module base surfaces. thing.

In order to achieve the above object, the camera module arrangement structure of the present invention may further include the following features.
(2) The step motor and the ISP are arranged separately on two side surfaces of the module base that form approximately 90 °.

  (3) The step motor and the ISP are arranged separately on two side surfaces of the module base that are substantially 180 ° to each other and that face each other.

  (4) The step motor and the ISP are arranged on one same side surface of the module base.

  (5) The image sensor and the ISP are arranged on the bottom surface of the module base.

  According to the present invention, the camera module can be configured compactly. In addition, the circuit board load due to the drop impact was reduced, and the reliability of the camera module was improved. In addition, it is easy to incorporate into an electronic device (master phone) such as a form telephone, and the master phone can be made compact.

  In the present invention, the module base supporting the lens holder is a substantially rectangular parallelepiped, the image sensor is arranged on the bottom surface (image formation position), and the step motor and ISP are selected by selecting four side surfaces around the module base. Arranged.

  1 is a front view of Embodiment 1 of the present invention, FIG. 2 is a sectional view thereof, and FIG. 3 is a plan view thereof. Reference numeral 1 denotes a module base, and the outer surface has a shape that fits in a substantially rectangular parallelepiped block. Although the optical axis is not shown, the direction is the vertical direction of the screen in FIGS. 1 and 2, and the direction perpendicular to the screen in FIG. Reference numeral 5 denotes a lens holder, which includes a cylindrical portion holding a photographing lens 5a (for example, a lens group having three lenses) and two tensions provided at the upper and lower end portions of the thickness. It has a protruding portion 5c.

  The cylindrical portion of the lens holder 5 is guided by a concave wall surface 1 a of the module base 1 that forms a concave surface that freely mates with the cylindrical portion. In addition, a guide post 6 planted in the notch 1b of the module base 1 is loosely fitted in the holes provided in the upper and lower projecting portions 5c, and the lens holder 5 is parallel to the optical axis in a predetermined range. Can slide into.

  A window 1b is provided at the bottom of the module base 1, which is the imaging surface of the lens 5a, and is held by an FPC, that is, a flexible circuit board 9, and faces an image sensor 8 such as a CMOS having many pixels. Further, the ISP 4 which is an integrated circuit for controlling images and photographing operations is mounted on the FPC 9 and is one of other side surfaces perpendicular to the side surface of the module base 1 to which the step motor 2 is fixed. The FPC 9 and the FPC 9 are disposed on the side surface located on the front side and fixed to the module base 1. The FPC 9 on which the image sensor 8 and the ISP 4 are mounted is a single body and is bent along two corners of the module base 1. A part of the FPC 9 is extended and connected to a terminal of the step motor 2 (assuming that it is on the lower surface side of FIGS. 1 and 2 which is one of the flat side surfaces of the motor).

  The step motor 2 fixed to the left side surface of the module base 1 in FIG. 1 has a flat shape instead of a generally cylindrical shape. This is an electromagnetic motor, which employs a planarly developed stator and coil, and a rotor mainly composed of a cylindrical permanent magnet, which are often used in watches, so that a flat shape can be achieved ( (The internal structure is not shown). The drive shaft 2a, which is an appropriately decelerated output end, protrudes in a direction perpendicular to the flat surface, and a flat-plate cam 8 is fixed to the tip. When a drive pulse generated from a control circuit (not shown) is supplied to the coil, the drive shaft 2a, and hence the cam 8, is rotated in the selected forward or reverse direction by an angle proportional to the number of pulses.

  A cam follower 5b, which is a pin planted on the side surface of the lens holder 5, is in contact with the outer periphery of the cam 8 from above as shown in FIGS. Reference numeral 7 denotes a coil spring compressed by a pressurizing spring. The upper end engages with the lower surface of the stepped portion 6a of the guide post 6 and the lower end engages with the upper surface of the protruding portion 5c on the lower side of the lens holder 5. Yes. That is, the lens holder 5 is always urged downward (in the direction toward the drive shaft 2 a) by the pressurizing spring 7 to give a necessary contact force to the cam follower 5 b and the cam 8.

  The outer periphery of the cam 8 is given a shape in which the radius changes spirally with the cam rotation angle, and the cam follower 5b is in contact with the cam follower 5b. Move in the direction of the optical axis). This movement is performed during the focus adjustment operation in the photographing preparation stage. However, when the control circuit ISP4 determines that the in-focus state has been achieved by the signal obtained from the image sensor 3, the drive signal of the step motor 2 is stopped and the lens holder 5 Maintains its position (autofocus operation complete), and the camera is ready for shooting operation (shutter release operation).

  In the first embodiment, the main components of the step motor 2, the image sensor 3, and the ISP 4 are densely arranged on the three surfaces around the module base 1, so that the camera module can be very compactly assembled. In addition, the circuit board exists only in the vicinity of the module base 1 and is light in weight with a small area. Therefore, even if the camera module receives an impact, the impact force load is small, the destruction resistance is increased, and the reliability is improved. did.

  4 is a front view of a camera module that is Embodiment 2 of the present invention, FIG. 5 is a sectional view, and FIG. 6 is a plan view. In this example, the inside of the module base 1 has the same structure as that of the first embodiment, and the same reference numerals are given to the corresponding members, so that unnecessary overlapping is not described. The difference from the first embodiment is that the ISP 4 is arranged so as to be parallel to the right side surface opposite to the left side surface where the step motor 2 of the module base 1 is provided, and the shape of the FPC 9.

  The step motor 2, the image sensor 3, and the ISP 4 are connected by a single FPC 9. In this example, since the terminal of the step motor 2 is assumed to be on the side where the drive shaft 2 a is located, the FPC 9 is arranged so as to be sandwiched between the step motor 2 and the module base 1. The FPC 9 holds the image sensor 3 on the lower surface side of the module base 1 and holds the ISP 4 on the right side surface side. The FPC 9 is further bent on the right side surface of the module base 1 so as to surround the ISP 4 and the end thereof extends, and this creates a space for inserting other parts, provides cushioning, and a connector for other circuits and power supplies. It is not particularly related to the arrangement (the flat step motor 2 and the ISP 4 are arranged on the opposite side surfaces of the module base) which is the purpose of the present invention. Also in this example, the compactness and high reliability of the camera module are maintained.

  Next, although not shown, the arrangement structure of the third embodiment will be described. In this example, the ISP 4 is arranged on the side surface of the module base 1 on the same side as the flat step motor 2. That is, the ISP 4 is arranged in parallel and in close contact with the outside of the step motor 2. The FPC 9 is connected by being appropriately bent. Also in this example, the camera module can be sufficiently improved in compactness and impact resistance.

  Further, although not shown, the arrangement structure of the fourth embodiment will be described. In this example, the ISP 4 is disposed so as to overlap the outside (lower side) of the image sensor 3. FPC9 is of course folded. Also in this example, the camera module can be sufficiently improved in compactness and impact resistance.

  According to the present invention, the compactness of the camera module, the compactness of the electronic device in which the camera module is incorporated, and the reliability of the camera module can be improved, and thus the industrial applicability is great.

It is a front view of Example 1 of the present invention. It is sectional drawing of Example 1 of this invention. It is a top view of Example 1 of the present invention. It is a front view of Example 2 of the present invention. It is sectional drawing of Example 2 of this invention. It is a top view of Example 2 of the present invention. It is a side view (partial sectional view) of a conventional example of the present invention.

Explanation of symbols

1 module base 1a concave wall 1b window 2 step motor 2a drive shaft 3 image sensor 4 ISP
5 Lens holder 5a Lens 5b Cam follower 5c Overhanging portion 6 Guide post 6a Stepped portion 7 Pressurizing spring 8 Cam 9 FPC
10 PC
11 Cylindrical motor 12 Worm 13 Worm gear 14 Cylindrical cam 15 Rotating shaft 16 Cam groove 17 Protrusion

Claims (5)

This is a focal plane perpendicular to the optical axis in the configuration in which the parts of the camera module are arranged on each surface of a block-shaped module base that forms a substantially rectangular parallelepiped containing a lens holder that moves within a predetermined range along the optical axis. An image sensor is disposed on the bottom surface, a flat step motor is closely disposed on one of the side surfaces of the module base, and an ISP is disposed in parallel with one of the surfaces of the module base. The camera module layout structure. 2. The camera module arrangement structure according to claim 1, wherein the step motor and the ISP are arranged separately on two side surfaces of the module base that form substantially 90 degrees. 2. The camera module arrangement structure according to claim 1, wherein the step motor and the ISP are arranged separately on two side faces of the module base that are substantially 180 [deg.] To face each other. 2. The camera module arrangement structure according to claim 1, wherein the step motor and the ISP are arranged to overlap each other on the same side surface of the module base. 2. The camera module arrangement structure according to claim 1, wherein the image sensor and the ISP are arranged to overlap with a bottom surface of the module base.

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