KR20060112520A - Small form factor camera module with a mechanical iris and shutter - Google Patents

Abstract

A sub-miniature camera module with a mechanical iris and a mechanical shutter is provided to maintain the constant displacement of the mechanical iris and the mechanical shutter with low power. A latching structure is an elastic body(36), and an end thereof is additionally installed at a surface of a driving member or a fixing member(37). The elastic body is formed at a surface of a base plate positioned oppositely to a surface of a shutter driving plate. The elastic body is also formed at a surface of the shutter driving plate. The elastic body is preferably a leaf spring. A friction force with a constant level is acted between the base plate and the shutter driving plate by the elastic body. When a driving force(53) generated by a driving magnet and a driving coil is larger than the friction force, an iris member and the shutter driving plate are driven.

Description

Small Form Factor Camera module with a Mechanical Iris and Shutter

1 is a schematic diagram showing the structure of a general micro camera module.

Figure 2 is a perspective view of the light amount adjustment mechanism applied to the micro camera module of the present invention.

3 is an exploded perspective view of the light amount adjusting mechanism of FIG. 2;

Figure 4 is a conceptual view for explaining the operation of the light amount control mechanism in the compact camera module according to the present invention.

5 is a schematic view including a latching structure for maintaining a constant displacement of the mechanical aperture and the shutter according to the first embodiment of the present invention.

6a and 6b are schematic views including a latching structure for maintaining a constant displacement of the mechanical aperture and the shutter according to the second embodiment of the present invention.

7 is a schematic view including a latching structure for maintaining a constant displacement of the mechanical aperture and the shutter according to the third embodiment of the present invention.

8 is a schematic view including a latching structure for maintaining a constant displacement of the mechanical aperture and the shutter according to the fourth embodiment of the present invention.

9A and 9B are schematic views including a latching structure for maintaining a constant displacement of a mechanical aperture and a shutter according to a fifth embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

1,2: lens group assembly 3,4: optical component

10: case 20: cover plate

21: drive coil 23: through hole

24: aperture portion 25: opening hole

26: shutter drive plate 27: link slit

28: base plate 29: fastening hole

30: fastening link 31: driving magnet

32: shutter link 33: magnetic foil

34: Clasp 34a: Protrusion

35: clasp 35a: groove

36: elastic body 37, 38: drive part or movable part

39: electrostrictive or magnetostrictive

40: mechanism in which electromagnetic or electrostatic force is formed

51: normal force 52: friction

53: driving force 54: external driving force (electric or magnetic field)

100: image sensor 101: peripheral circuit portion

102: image sensor

The present invention relates to an ultra-compact camera module, and more particularly, includes a latching structure having a mechanical aperture and a shutter, and capable of maintaining a constant displacement of the mechanical aperture and the shutter. The present invention relates to a miniature camera module that can significantly reduce the volume of the entire system and be applicable to various applications requiring a miniature camera module including a portable terminal.

Recently, with the development of communication technology and digital information processing technology, portable terminal technology in which various functions such as information processing and arithmetic, communication, image information input and output are integrated is emerging.

Examples include PDAs equipped with digital cameras and communication functions, and mobile phones equipped with digital cameras and PDA functions. Due to the development of digital camera technology and information storage capability, high-end digital camera modules Mounting is becoming more and more common.

With the development of various technologies to support this, a mega pixel image sensor is used in a digital camera module mounted on a portable terminal, so that optical zoom and auto focus functions can be used. In addition, the importance of the mechanical shutter and the mechanical iris is becoming more important.

The CCD uses two types of scan modes, interlaced scan and progressive scan.

The interlaced method scans an image twice in a manner used in a conventional CCD for video. When the image is divided into two scans, light is continuously emitted until the second scan after one scan is performed. This will fall.

Therefore, in order to acquire a high quality image, the process of blocking light in two completely scanning steps using a mechanical shutter must be considered.

In contrast, in the days of 350,000-pixel digital cameras, a progressive scan method that scans all pixels at once was used. This method has the advantage that there are no errors due to time intervals, and therefore, there is no mechanical shutter. Control was possible only with the shutter.

However, in recent digital cameras with more than 3 million pixels, the interlaced scan method is being re-adopted to obtain more light at the same CCD size and expect better image quality.

In this case, as described above, the expected image quality cannot be obtained only by the electronic shutter. Therefore, the development of a technique for employing a mechanical shutter has been actively performed.

The mechanical shutter is a function that blocks the unnecessary light and upgrades the picture quality by actually blinking the screen when the picture is taken as if a person blinks the eye. The smear phenomenon, which appears as lines, is blocked by hardware rather than software, so that a clearer picture can be obtained.

When the mechanical aperture is adopted, it can be usefully used to obtain a clear picture with a suitable exposure value with a mechanical shutter by adjusting the amount of incoming light, and can adjust the depth of field, such as a general cameraman. Photographs of various moods that reflect the subjectivity of the camera can be obtained from the compact camera module.

In addition, the camera adopting a mechanical aperture structure has a function to reduce aberration caused by the difference between the light entering through the center of the lens and the light entering through the periphery. In addition, the light in the center of the lens is mainly used for the image, thereby obtaining a clear picture with low aberration.

Therefore, the adoption of a mechanical aperture has been studied as an essential component of a high-resolution mega pixel camera.

The application of mechanical shutters and apertures to ultra-compact digital camera modules requires a driver that takes up relatively small volume and can meet performance such as fast startup speed, low power consumption and large displacement.

In particular, there is a need for a driver that can cope with an increase in the required displacement as the size of the image increases. In the case of a conventional general magnetic actuator, a large number of parts are used, and thus there is a limitation in unit cost and size. There is a limit to increase, and using only the on / off drive is insufficient to implement the same function as the conventional mechanical aperture.

In addition, in the case of moving the moving part by a drive that rotates, such as a stepping motor (stepping motor), since the gears are used in the power transmission process, the number of parts and the structure is complicated.

In addition, the response speed is low, and there are disadvantages such as friction and noise of the gear part. In the case of the mechanical shutter and aperture driver employing the above-described method, it is difficult to manufacture a low-cost driver due to a complicated structure, and there is a limitation in size in miniaturization.

An object of the present invention devised to achieve the above object is to install a mechanical shutter and aperture using a linear actuator of VCM (Voice Coil Motor) method manufactured by fine precision machining technology or micromachining process, thereby improving the image quality. The present invention provides a camera module that can be manufactured in various structures according to a method of arranging a shutter and an aperture and an optical module.

Another object of the present invention is to integrate the ultra-small mechanical shutter and aperture to reduce the weight and size of the camera.

Still another object of the present invention is to maintain a constant displacement of the mechanical aperture and the shutter at low power by adding a latching function in the driving method.

In order to achieve the above object, the micro camera module of the present invention includes a base plate having a through hole formed therein; A shutter driving plate disposed on the base plate, the shutter driving plate including a predetermined opening hole, a driving magnet formed on one side of the opening hole, and one or more pairs of shutter links installed on both sides of the opening hole; An aperture part disposed between the base plate and the shutter driving plate to open and close the through hole by manipulating the shutter link; A cover plate coupled to the base plate and having a through hole formed at a position corresponding to the through hole of the base plate, wherein a drive coil is installed to generate a magnetic force in the drive magnet to displace the shutter drive plate; And a light amount adjusting mechanism including a latching structure for maintaining a constant displacement of the mechanical aperture and the shutter.

Magnetic force generation in the driving magnet is characterized in that the electric power is supplied from the power source.

The diaphragm may include a pair of diaphragm plates having a link slit connected to the shutter link.

The latching structure may be implemented in various forms. First, the latching structure is an elastic body fixed to one surface of a base plate or a shutter driving plate whose one end faces each other. Accordingly, a certain level of friction is applied between the base plate and the shutter drive plate by the elastic body, and the iris and the shutter drive plate are driven when the friction force is smaller than the drive force generated by the drive magnet and the drive coil. do.

The elastic body is preferably a leaf spring.

Secondly, the latching structure is a magnetic foil formed on one surface of the base plate facing the shutter drive plate. Accordingly, the attraction force generated between the driving magnet and the magnetic material foil generates a certain level of friction force between the driving magnet and the base plate, and when the driving force generated by the driving magnet and the driving coil is greater than the friction force, the aperture part and the shutter The drive plate is driven.

Thirdly, the latching structure is an electrostrictive or magnetostrictive element whose one side is attached to the base plate or the shutter driving plate, and the other side is in contact with the shutter driving plate or the base plate due to the frictional force. Accordingly, when the electric field or the magnetic field is applied, the electrostrictive element or the magnetostrictive element is deformed to remove the frictional force, thereby driving the aperture part and the shutter drive plate.

Fourthly, the latching structure is a mechanism in which an electromagnetic force or an electrostatic force is formed on one surface of the base plate facing the shutter driving plate and is formed in a row at a predetermined interval. Accordingly, when a force greater than the force hindering the driving is applied for a predetermined time from the outside, the movement of the aperture and the shutter driving plate can be adjusted only by the interval of the means for limiting the predefined movement.

Fifth, the latching structure is formed on one surface of the shutter driving plate or the base plate, one surface of which is formed on one surface of the base plate or the shutter driving plate and a female clasp which is formed with a plurality of continuous grooves. It comprises a clasp which is formed with one or more projections to fit in the groove of the clasp.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram showing a structural diagram of a general micro camera module.

A camera employing a general CMOS or CCD image sensor is composed of an image sensor 100 and a lens group assembly 1 composed of one or more lenses in addition to the peripheral circuit portion 101.

Therefore, as shown in the left side of FIG. 1, the lens group assembly 1, a case 10 for accommodating the lens group assembly 1, and a lower portion of the lens group assembly 1 are installed in the lens. The image sensor 100 receives an image received from the group assembly 1 and a peripheral circuit unit 101 connected to the image sensor 100 to grasp information of the image sensor 100.

Recently, as a mega pixel image sensor is used in a digital camera module mounted on a portable terminal, a plurality of lens group assemblies and an optical zoom are provided to add high quality images and additional convenience functions. (Optical Zoom) and the Auto Focus (Auto Focus) function of the integration of a number of optical components are increasingly being adopted.

Accordingly, as shown on the right side of FIG. 1, in addition to the lens group assembly 2, one or more optical parts 3 and 4 including another lens group assembly and / or an aperture and a shutter are included. At the bottom end, the image sensor 102 is installed.

However, in the compact digital camera module, the volume occupied by the camera module occupies a relatively small volume relative to the size of the entire device, but must satisfy performance such as fast starting speed, low power consumption, and large displacement. When the movable part is moved by a driver that performs a rotational motion such as a stepping motor, the number of parts and the structure thereof are complicated, and the volume is large due to the size of the motor.

2 is a perspective view of a light amount adjusting mechanism applied to the micro camera module of the present invention, and FIG. 3 is an exploded perspective view of the light amount adjusting mechanism of FIG. 2.

The light amount adjusting mechanism according to the present invention may be used as a part of the lens group assembly of FIG. 1 or as a part of the ultra-compact camera module structure to serve to adjust the amount of image light, and compared with a mechanical shutter and aperture structure using a conventional motor. It has the advantage of using fewer parts and taking up less volume.

As shown in Figures 2 and 3, the light amount control mechanism according to the present invention includes a base plate 28, the through hole 23 and the fastening hole 29 is formed; A shutter driving plate 26 having an opening hole 25 and a shutter link 32 provided with a driving magnet 31; An aperture portion 24 having a link slit 27; It includes a cover plate 20 having a coupling link 30, a through hole 23 and a drive coil 21 formed to be assembled with the base plate 28.

The through hole 23 is formed to correspond to the same position on the base plate 28, the aperture 24, and the base plate 28, and the shutter drive plate 26 has an area larger than the through hole 23. The rectangular opening of the opening 25 is formed, the lower portion of the opening hole 25 is provided with a drive magnet 31.

The fastening hole 29 of the base plate 23 is coupled to the fastening link 30 of the cover plate 20, the fastening hole 29 is formed in the cover plate 20, the fastening link 30 May be formed on the base plate 23.

Of course, it is also possible to fasten with a fastening means other than the fastening link 30, for example, rivets.

In one embodiment of the present invention, the fastening hole 29 and the fastening link 30 are formed at both upper sides of the base plate 23 and the cover plate 20 and below the through hole 23.

The shutter driving plate 26 and the upper both sides of the aperture 24 are chamfered so as not to be disturbed by the fastening link 30.

The shutter drive plate 26 has a shutter link 32, which is constrained to the link slit 27 of the aperture 24.

The driving magnet 31 installed in the shutter driving plate 26 is installed at a position where the magnetic force can act the greatest between the driving coil 21 of the cover plate 20.

The diaphragm 24 is formed by overlapping two diaphragm plates that are symmetrical with each other. When the gap between the two diaphragm plates is maximized, the through hole 23 is completely opened. When the interval between the minimum is the through-hole 23 is closed.

The adjustment of the interval between the two aperture plates is made by vertical movement of the shutter links 32 of the shutter drive plate 26 connected to the link slits 27 respectively formed on the two aperture plates.

As described above, the diaphragm plate may be configured not only in one pair but also in two or more pairs.

The vertical movement of the shutter link 32 is made by the driving magnet 31 and the driving coil 21.

The cover plate 20 has a through hole 23 formed at an upper portion thereof, and a driving coil 21 is installed at a lower portion thereof.

4 is a conceptual view for explaining a method of operating the light amount control mechanism in the compact camera module according to the present invention.

In the light amount adjusting mechanism of the present invention, the aperture 24 positioned around the through hole 23 opens and closes the through hole 23 by using an electromagnetic force generated between the driving coil 21 and the driving magnet 31.

That is, when a current is supplied to the drive coil 21, the shutter drive plate 26 linearly moves up and down by the electromagnetic force generated between the drive coil 21 and the drive magnet 31. Two aperture plates of the aperture part 24 positioned around the through hole 23 by the shutter link 32 and the link slit 27 which are axially assembled with the 26 close or open the through hole 23. .

Therefore, the light amount adjusting mechanism may act as a shutter and an aperture by controlling the amount of image light and controlling the time that the image is exposed to the image sensor by controlling a current to the driving coil 21.

The aperture and shutter structure of the present invention can be applied to any optical device that requires the control and control of the amount of light in addition to the compact camera.

In the present invention, various types of latching structures are formed to maintain a constant displacement of the mechanical aperture and the shutter. The description of the form of the latching structure is described in more detail by FIGS. 5-9B.

Hereinafter, in the present invention, the base plate and the cover plate may be referred to as 'fixing part', the shutter driving part and the aperture part as 'drive part'.

5 is a schematic diagram including a latching structure for maintaining a constant displacement of the mechanical aperture and the shutter according to the first embodiment of the present invention.

As shown in Fig. 5, the latching structure is an elastic body 36, one end of which is attached (fixed) to one surface of the driving part or the fixing part 37. For example, the elastic body 36 may be formed on one surface of the base plate 28 facing one surface of the shutter driving plate 26 or the shutter driving plate facing one surface of the base plate 28 ( It may be formed on one surface of 26).

Reference numeral 51 is a vertical drag.

The elastic body 36 is preferably a leaf spring.

Accordingly, a predetermined level of friction force 52 is applied between the base plate 28 and the shutter drive plate 26 by the elastic body 36, and is generated by the drive magnet 31 and the drive coil 21. When the driving force 53 is greater than the friction force 52, the aperture part and the shutter driving plate are driven.

6A and 6B are schematic views including a latching structure for maintaining a constant displacement of the mechanical aperture and the shutter according to the second embodiment of the present invention.

6A and 6B, the latching structure is a magnetic foil 33 formed on one surface of the base plate 28 facing the shutter drive plate 26. Accordingly, the attraction force generated between the driving magnet 31 and the magnetic foil 33 generates a predetermined level of friction force between the driving magnet 31 and the base plate 28, and the driving magnet 31 and the driving coil ( When the driving force generated by 21) is greater than the friction force, the aperture part and the shutter drive plate may be driven to maintain a constant displacement of the mechanical aperture and the shutter.

6B is a magnetic flux distribution diagram before the magnetic foil 33 of the present invention is formed, and the right diagram of FIG. 6B is a magnetic flux distribution diagram after the magnetic foil 33 of the present invention is formed. As shown in the right figure of FIG. 6B, when the magnetic foil 33 is provided, a force (human force) (vertical drag force) generated in the vertical direction from the driving magnet 31 to the magnetic foil 33 is generated, and the driving magnet is provided. The magnetic flux between the 31 and the magnetic foil 33 is distributed more than in FIG. 6A.

In the present invention, instead of the magnetic foil 33, by employing an electrode structure of a type capable of generating an electrostatic force may be implemented by using the electrostatic force generated when a voltage is applied between the electrode structures.

7 is a schematic diagram including a latching structure for maintaining a constant displacement of the mechanical aperture and the shutter according to the third embodiment of the present invention.

As shown in FIG. 7, the latching structure is a predistortion device or magnetostrictive device, one surface of which is installed in the driving unit or the fixing unit (not shown), and the other surface of the latching structure contacts the fixing unit or the driving unit 38 due to frictional force. (39).

The pre-distortion element or magneto-distortion element 39 is a device that changes the shape in a predetermined direction when placed in the electric or magnetic field, respectively, by using a latching structure that can limit the movement of the drive unit by adjusting the external electric or magnetic field Can be implemented.

Accordingly, when an electric field or a magnetic field is applied to the electrostrictive element or magnetostrictive element 39, the electrostrictive element or magnetostrictive element 39 is deformed to remove frictional force, thereby driving the aperture and the shutter driving plate.

That is, as shown in the left figure of FIG. 7, before the electric or magnetic field is applied, one surface of the electrostrictive element or magnetostrictive element 39 is a driving part or a moving part (not shown) (for example, the base plate of FIG. 3). The other surface of the electrostrictive element or magnetostrictive element 39 is in contact with the side of the movable portion or the drive portion 38 (for example, the shutter drive plate of Fig. 3) and is fixed due to the frictional force.

Then, as shown in the right figure of FIG. 7, when the electric or magnetic field is applied, the electrostrictive element or magnetostrictive element 39 is deformed to remove the friction force, thereby driving the aperture and the shutter drive plate do.

8 is a schematic view including a latching structure for maintaining a constant displacement of the mechanical aperture and the shutter according to the fourth embodiment of the present invention.

As shown in FIG. 8, the latching structure is a mechanism in which an electromagnetic force or an electrostatic force is formed on a surface of a plurality of fixed parts (not shown) (for example, the base plate of FIG. 3) formed in a row at predetermined intervals. to be. Accordingly, when a force greater than the force hindering the driving is applied for a predetermined time from the outside, the movement of the driving unit can be adjusted only by the interval of the means for limiting the predetermined movement, and the movement is controlled at a predetermined interval using the same. Means can be implemented. Reference numeral 51 is a vertical drag, 52 is a friction force, 53 is a driving force.

9A and 9B are schematic views including a latching structure for maintaining a constant displacement of a mechanical aperture and a shutter according to a fifth embodiment of the present invention.

As shown in FIGS. 9A and 9B, the latching structure is formed on one surface of a driving part or a fixing part (not shown) (for example, the base plate of FIG. 3), and one surface of the plurality of continuous grooves ( 35a) is formed on one side of the female clasp 35 and the fixed portion or the driving portion (not shown (for example, the shutter drive plate of Figure 3)), the one surface is formed in the groove (35a) of the female clasp It comprises a clasp 34 is formed one or more projections (34a) to be fitted.

As shown in FIG. 9B, the projection 34a of the clasp 34 crosses the groove 35a of the clasp 35 one by one to adjust the displacement of the mechanical aperture and the shutter step by step.

As described above, the present invention can minimize the power consumption by forming a latching structure to maintain a constant displacement of the mechanical aperture and the shutter.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

Unlike conventional electronic shutters, the ultra-compact camera module according to the present invention not only improves image quality by adjusting the amount of light entering an image sensor by a mechanical shutter and an aperture, but also implements the electronic system, thereby realizing the entire system. Significantly reduce the volume and can be applied to a variety of applications that require a small camera module, such as a portable terminal.

In addition, in the present invention, by adding a latching function in the driving method, it is possible to maintain a constant displacement of the mechanical aperture and the shutter at low power.

Claims (13)

A base plate having a through hole formed therein; A shutter driving plate disposed on the base plate, the shutter driving plate including a predetermined opening hole, a driving magnet formed on one side of the opening hole, and one or more pairs of shutter links installed on both sides of the opening hole; An aperture part disposed between the base plate and the shutter driving plate to open and close the through hole by manipulating the shutter link; A cover plate coupled to the base plate and having a through hole formed at a position corresponding to the through hole of the base plate, wherein a drive coil is installed to generate a magnetic force in the drive magnet to displace the shutter drive plate; And a light amount adjusting mechanism comprising a latching structure for maintaining a constant displacement of the mechanical aperture and the shutter. The ultra-compact camera module of claim 1, wherein the diaphragm comprises at least one pair of diaphragm plates having link slits connected to the shutter link. The ultra-compact camera module of claim 1, wherein the magnetic force is generated from the driving magnet by receiving electricity from a power source. The ultra-compact camera module according to any one of claims 1 to 3, wherein the latching structure is an elastic body whose one end is fixed to one surface of the base plate or the shutter driving plate facing each other. The method of claim 4, wherein a predetermined frictional force is applied between the base plate and the shutter drive plate by the elastic body, the aperture portion and the shutter drive plate when the friction force is smaller than the drive force generated by the drive magnet and the drive coil. Miniature camera module, characterized in that driven. The micro camera module of claim 5, wherein the elastic body is a leaf spring. The ultra-compact camera module according to any one of claims 1 to 3, wherein the latching structure is a magnetic foil formed on one surface of the base plate facing the shutter driving plate. 8. The diaphragm according to claim 7, wherein the attraction force generated between the driving magnet and the magnetic foil generates a certain level of friction force between the driving magnet and the base plate, and the driving part is generated when the driving force generated by the driving magnet and the driving coil is greater than the friction force. And the compact camera module characterized in that the shutter drive plate is driven. The latching structure according to any one of claims 1 to 3, wherein the latching structure is an electrostrictive or magnetostrictive element whose one side is additionally installed on the base plate or the shutter driving plate, and the other side is in contact with the shutter driving plate or the base plate due to the frictional force. Miniature camera module, characterized in that. The micro camera module of claim 9, wherein when the electric field or the magnetic field is applied, the electrostrictive element or the magnetostrictive element is deformed to remove the frictional force, thereby driving the aperture part and the shutter driving plate. The ultra-compact camera according to any one of claims 1 to 3, wherein the latching structure is a mechanism in which a plurality of latching structures are formed on one surface of the base plate facing the shutter driving plate so as to have an electromagnetic force or an electrostatic force formed in a line at a predetermined interval. module. 12. The movement of the aperture portion and the shutter drive plate according to claim 11, wherein, when a force greater than the force hindering the driving is applied for a predetermined time from the outside, the movement of the aperture and the shutter drive plate can be adjusted only by the interval of the means for limiting the predefined movement. Miniature camera module. The latching structure according to any one of claims 1 to 3, wherein the latching structure is formed on one surface of the shutter driving plate or the base plate, one side of which is formed a plurality of continuous grooves, and one surface of the base plate or the shutter driving plate. Is formed in, the one side of the micro camera module, characterized in that it comprises a clasp formed with one or more projections to be inserted into the groove of the clasp.

Images