KR20110025512A - Camera lens assembly - Google Patents

Abstract

PURPOSE: A camera lens assembly is provided to prevent the malfunction of a camera lens assembly by removing foreign materials from the assembly or being easily replaced with another one. CONSTITUTION: A main frame has some portion which is open in an optical axis direction. An image sensor is formed at one end of the main frame, and is arranged in the optical axis direction. A lens assembly(103) reciprocates in the optical axis direction, and has at least one lens. A driving unit assembly reciprocates the lens assembly in the optical axis direction.

Description

Camera Lens Assembly {CAMERA LENS ASSEMBLY}

  The present invention relates to a camera lens assembly, and in particular, in the configuration of automatically adjusting the focal length of the lens in an optical device mounted on a digital camera or a mobile communication terminal, it is easy to miniaturize and can improve image correction performance. A camera lens assembly.

Recently, with the development of digital camera manufacturing technology, mobile communication terminals equipped with compact and lightweight camera lens assemblies are gradually eating into the compact digital camera market. As the mounting of the camera lens assembly to a mobile communication terminal and the like has become common, efforts are now being made to improve the performance of such a camera lens assembly. For example, an auto focusing function for correcting a focal blur caused by a shooting distance of a subject when capturing an image has been installed in an expensive mobile communication terminal, but it is gradually being installed in an entry-level terminal.

Although the performance of the camera lens assembly and the precision of its manufacturing technology are improved and the mobile communication terminal is gradually eating into the compact digital camera market, the main functions of the mobile communication terminal, that is, the maintenance and portability of the communication function, are considered. At this time, there is a limit to the performance of the camera lens assembly mounted on the mobile communication terminal to the same level as that of the digital camera.

That is, in the case of a general compact digital camera, an optical zoom function and an auto focus function are basically installed. In addition, some cameras are equipped with image stabilization. However, since mobile communication terminals have to take portability into consideration as a communication function as a main function, optical zoom function and auto focusing function and It is having a hard time with the camera shake correction function.

In other words, the optical zoom and image stabilization functions of the camera lens assembly mounted on the mobile communication terminal are extremely limited due to the difficulty in realizing the space and the performance of the camera lens assembly. This easy auto-focusing feature is being installed in camera lens assemblies embedded in mobile communication terminals.

However, the conventional camera lens assembly with an auto focusing function does not flexibly cope with the technological evolution of miniaturization and slimming of mobile communication terminals. In addition, in the performance implementation, it is virtually impossible to check whether the lens has been moved to a target position by using an open loop control method that moves the lens according to the intensity of the current applied from the image sensor assembly. The phenomenon of skipping a section occurs, which causes a limitation in providing a clear image to a user.

In addition, as the camera lens assembly becomes higher and higher in performance, the actuator mounted thereon has a higher resolution and a need for a product capable of shortening the auto focusing time as the auto focusing area is increased according to the high pixel. have. In addition, considering that the high-pixel camera lens assembly is expensive, there is a need for a product that can contribute to reducing the defect of the auto focus actuator and improving the yield of the camera lens assembly.

Accordingly, the present invention is to provide a camera lens assembly capable of precise resolution of the resolution by realizing high-precision position control, and can shorten the auto-focus adjustment time without the need for a separate damping member such as a spring.

In addition, the present invention is to provide a camera lens assembly that can improve the yield by reducing the defects caused by the foreign matters as the resolution defects and the size of the foreign matters that can affect the image is reduced according to the increase in the lens resolution sensitivity. .

In addition, the present invention, by arranging a magnetic material in the lens assembly, and a yoke in the drive assembly to support the lens assembly with the attraction force between them, and configured to be movable movable, when a failure of the camera lens assembly occurs An object of the present invention is to provide a camera lens assembly that can reduce the manufacturing cost by facilitating replacement of the lens assembly and contributing to the simplification of the manufacturing process.

Accordingly, the camera lens assembly according to the present invention,

A main frame at least partially open in the optical axis direction;

An image sensor disposed at one end of the main frame and aligned in the optical axis direction;

A lens assembly accommodated in the main frame and moving forward and backward in the optical axis direction, the lens assembly having one or more lenses; And

And a driving unit assembly for moving the lens assembly back and forth in the optical axis direction.

The driving unit assembly may include a magnetic body disposed on the lens assembly, a coil disposed on the main frame to face the magnetic body and generating an electric field as power is applied, and the coil being fixed on the main frame, between the magnetic body. And a yoke which is disposed to face the magnetic material,

When power is not applied to the coil, the lens assembly may be stopped at a predetermined position by the attraction force between the magnetic material and the yoke.

In this case, the other end of the main frame is provided as an open end, the camera lens assembly is preferably provided with a cover provided on the other end of the main frame.

In addition, the lens assembly moves forward and backward along the optical axis direction, and the cover limits the distance from the lens assembly to the image sensor within a predetermined distance.

The camera lens assembly may further include a binding piece extending from the cover, a binding hook formed by cutting a portion of the binding piece, a binding groove formed in the main frame, and a hook groove formed in a portion of the binding groove. When the cover is coupled to the main frame, the binding piece is engaged with the binding groove, the binding hook is engaged with the hook groove, respectively.

At this time, the binding piece is preferably formed so that a pair of facing each other at the edge of the cover.

Further, when no power is applied to the coil, the lens assembly stops at a position where the center of the magnetic body faces the center of the yoke,

When power is not applied to the coil, the lens assembly may move close to the image sensor by the attraction force between the magnetic material and the yoke, but may be stopped by interfering with a portion of the main frame.

At this time, the portion of the yoke is bent to extend to surround the coil, the attraction force between the bent portion of the yoke and the magnetic body can move the magnetic body and the lens assembly close to the image sensor.

In addition, by having a avoidance groove formed in the main frame it is possible to accommodate the bent portion of the yoke in the avoidance groove.

On the other hand, the camera lens assembly is provided in the drive unit assembly, the guide member extending along the optical axis direction, the support member provided in the lens assembly, extending along the optical axis direction, the guide member and the support member Further provided with balls (balls) between, the support member is disposed facing the guide member, it is preferable to maintain a state spaced apart from the guide member by the balls.

In addition, by further provided with a position detection sensor surrounded by the coil on the main frame, it is possible to detect the position of the magnetic material.

Camera lens assembly configured as described above is easy to assemble, separate the lens assembly from the main frame, the assembly is simplified, there is an advantage that can reduce the manufacturing cost. In addition, since the lens assembly can be easily separated from the main frame, even if a defect caused by a foreign material or the like can be easily removed by replacing the lens or removing a foreign material, the defect of the camera lens assembly itself is improved and the yield of the camera lens assembly is improved. Can contribute to

Furthermore, by using a position sensor such as a hall sensor, the position change of the magnetic material, and ultimately the position change of the lens assembly, may be detected, and thus the focus adjustment may be precisely controlled.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 to 8, the camera lens assembly 100 according to the preferred embodiment of the present invention enables the lens assembly 103 to be moved forward and backward on the main frame 101 where the image sensor 121 is installed. The lens assembly 103 is moved forward and backward by using the magnetic material 145 and the coil 147. At this time, by monitoring the position of the magnetic body 145 using a position sensor 149 such as a hall sensor, it is possible to detect a change in the position of the lens assembly 103 to generate a control signal necessary for focus adjustment. In addition, by providing a ball bearing structure, the lens assembly 103 can be moved back and forth smoothly.

The main frame 101 serves as a housing of the camera lens assembly 100, and the image sensor 121 is mounted at one end thereof, and the other end thereof is formed as an open end 113. In this case, one side of the main frame 101 may also be provided as an open end to install the driving unit assembly 104 for moving the lens assembly 103 forward and backward. In addition, the inner space of the main frame 101 has a cylindrical cylinder shape to accommodate the lens assembly 103. One end of the main frame 101 is formed with a first opening 111 corresponding to the image sensor 121 to provide a photographing path. Although not shown, an infrared filter is mounted in the first opening 111, and the image sensor 121 detects only an image incident through the infrared filter.

The image sensor 121 is supplied with power and mounted on a separate circuit board 123 to output an image signal of a photographed image, and is provided in the form of an assembly 102. The circuit board 123 is a power source. Or circuit patterns for providing a control signal and transferring the output image signal. In this case, the image sensor 121 may be connected to circuit patterns of the circuit board 123 by wire bonding. The circuit board 123 may be formed of a rigid circuit board, a flexible circuit board, or a combination thereof, and preferably includes a connector connected to a main board of a mobile communication terminal or a digital camera.

The lens assembly 103 includes at least one lens and is accommodated in the main frame 101 to move forward and backward in the optical axis direction of the image sensor 121. At this time, it is obvious that the lens provided in the lens assembly 103 should be aligned with the optical axis of the image sensor 121. The lens assembly 103 maintains an outer circumferential surface of the lens assembly 103 spaced apart from an inner circumferential surface of the main frame 101, which is caused by the driver assembly 104, which will be described in more detail below.

As mentioned above, the driver assembly 104 is for moving forward and backward of the lens assembly 103, and is mounted on the main body 101 and the magnetic material 145 mounted to the lens assembly 103. The coil 147 has a main configuration. The lens assembly 103 may be provided with a groove 131 for firmly fixing the magnetic body 145.

It is preferable that other components except the magnetic body 145 of the driving unit assembly 104 are installed in a fixed state in the main frame 101. At this time, when the driving unit assembly 104 is installed in the main frame 101, the open side of the main frame 101 is preferably closed. The drive unit assembly 104 includes a yoke 148, and thus, the electric field generated when the power is applied to the coil 147 and the magnetic field of the magnetic body 145 between the coil 147 and the magnetic body 145. I'm focused. In the present embodiment, the yoke 148 is installed to face the magnetic body 145 with the coil 147 interposed therebetween, and is fixed on the main frame 101. At this time, if power is not applied to the coil 147, an attraction force is generated between the magnetic body 145 and the yoke 148 to provide a force for bringing the lens assembly 103 into close contact with the driving unit assembly 104. Done. As a result, the lens assembly 103 may maintain a state in which the outer circumferential surface of the lens assembly 103 is spaced apart from the inner circumferential surface of the main frame 101 even without installing a separate support structure.

In addition, the driving unit assembly 104 may include a position sensor 149 attached to the yoke 148 and surrounded by the coil 147. The position sensor 149 is for monitoring the position of the lens assembly 103 and the change of the position. In this case, since the magnetic body 145 is installed in the lens assembly 103, the position of the lens assembly 103 may also be detected by detecting the position of the magnetic body 145. Hall sensor is useful as a possible device.

In addition, as the position sensing means 149, a separate light emitting diode and a photodiode are disposed on the yoke 148, and the lens assembly 103 reflects the light emitted from the light emitting diode in the direction of the photodiode. You may form a pattern. In this case, if the reflective pattern is able to change the intensity of the light emitted according to the position, the photodiode may detect the position of the lens assembly 103 by detecting it.

On the other hand, when the lens assembly 103 is in direct contact with the driving unit assembly 104 by the attraction force between the magnetic body 145 and the yoke 148, specifically, the magnetic body 145 is the coil 147 In close contact with the position sensor 149, a lot of driving force is required for the forward and backward movement of the lens assembly 103. Therefore, a predetermined distance is secured between the lens assembly 103 and the driver assembly 104, specifically, between the magnetic body 145 and the coil 147 or the position sensor 149 using a ball bearing structure.

In the present exemplary embodiment, the ball bearing structure includes guide members 141 provided on both sides of the yoke 148, a support member 143 provided on the lens assembly 103, and the guide member ( It consists of a number of balls 142 provided between the 141 and the support member 143.

The guide member 141 extends parallel to the optical axis direction of the image sensor 121, and at least one has a groove having a 'V' shape. Similarly, the support member 143 also extends parallel to the optical axis direction of the image sensor 121, and has a 'V' shaped groove. When the lens assembly 103 and the driver assembly 104 are installed in the main frame 101, the balls 142 are positioned in the grooves of the guide member 141 and the support member 143, respectively. In this case, each of the balls 143 is accommodated in the groove of the guide member 141, the other portion is received in the groove of the support member 143, the support member 143 to the guide member 141 It will have a diameter that is not in contact.

Through this ball bearing structure, a certain distance is secured between the lens assembly 103 and the driving unit assembly 104, specifically, between the magnetic body 145 and the coil 147 or the position detection sensor 149. When power is applied to the coil 147, the electric field by the coil 147 and the magnetic field of the magnetic body 145 interact with each other to move the lens assembly 103 back and forth. At this time, the balls 142 by rolling between the guide member 141 and the support member 143, thereby smoothly moving forward and backward of the lens assembly 103. Meanwhile, when the balls 142 perform rolling operations, noise or heat may be generated due to friction, and thus, lubricant may be injected into the grooves of the guide member 141 and the support member 143.

When the lens assembly 103 and the driver assembly 104 are installed in the main frame 101, the cover 105 is coupled to the other end of the main frame 101 to close the inner space. The cover 105 is provided with a second opening 151 penetrating in the optical axis direction to provide a photographing path and is fixed to the main frame 101 by providing at least one binding piece 153. In the present embodiment, the binding pieces 153 are formed at both edges of the cover 105 to face each other, and have a binding hook 155 formed by cutting a portion thereof. The binding hook 155 has a shape bent inward.

In order to couple the cover 105, the binding groove 115 is formed on the outer circumferential surface of the main frame 101, the hook groove 117 is formed in the binding groove 115 again. When the cover 105 is coupled to the main frame 101, the binding piece 153 is accommodated in the binding groove 115, and the binding hook 155 is engaged with the hook groove 117. As a result, the cover 105 is firmly bound to the main frame 101.

On the other hand, as the lens assembly 103 moves forward and backward, the range is limited by the main frame 101 and the cover 105. Specifically, at one end of the main frame 101, a mechanism provided around the first opening 111 may interfere with the lens assembly 103 and may no longer retreat close to the image sensor 121. At the other end of the main frame 101, the cover 105 may interfere with the lens assembly 103 and move further away from the image sensor 121. At this time, the lens assembly 103 to damp the noise or impact by installing a damper 159 (shown in FIG. 8) in the portion in contact with the mechanism around the first opening 111 or the cover 105. desirable.

When the assembly is completed, if no power is applied to the coil 147, the magnetic body 145 is in a direction in which its center (Mc; shown in FIG. 7) is aligned with the center (Yc) of the yoke 148. Will tend to move to. This is due to the attraction between the magnetic body 145 and the yoke 148. Accordingly, if the lens assembly 103 is capable of moving forward and backward without any interference, the center of the magnetic body 145 is the center of the yoke 148 when power is not applied to the coil 147. Will be moved to the position aligned with (Yc).

However, it is preferable to fix the lens assembly 103 before the center Mc of the magnetic body 145 is aligned with the center Yc of the yoke 148. This is to maintain a stable stop state when the lens assembly 103 remains stationary only by the attraction between the magnetic material 145 and the yoke 148 while the lens assembly 103 is capable of moving forward and backward before the camera lens assembly 100 operates. Because it is difficult to do.

6 and 7 illustrate the driving unit assembly 104 in the initial state of assembling the camera lens assembly 100 according to the present embodiment. In the present embodiment, in the state in which the camera lens assembly 100 is assembled, the lens assembly 103 is in a state of being interfered with an object around the first opening 111 and no longer toward the image sensor 121. Can't move. At this time, the magnetic body 145 is located above the yoke 148, and has a tendency to move downward, since the lens assembly 103 is already interfered with the mechanism around the first opening (111). The lens assembly 103 can no longer move downward and maintain a stable stationary state.

Meanwhile, in this initial state, a portion of the yoke 148 may be bent and extended to further stabilize the stationary state of the lens assembly 103. The bent portion of the yoke 148 is disposed to surround the coil 147, and the attraction force between the magnetic body 145 and the bent portion of the yoke 148 is a force to move the magnetic body 145 further downward. Will be generated.

In this case, the main frame 101 may be provided with a avoidance groove 119 to accommodate the bent portion of the yoke 148. This is to prevent the magnetic body 145 from coming into close contact with the bent portion of the yoke 148 before the lens assembly 103 interferes with the mechanism around the first opening 111. By preventing the magnetic body 145 from coming into direct contact with the bent portion of the yoke 148, it is possible to reduce the driving force required when initially driving the lens assembly 103.

When photographing an image, the camera lens assembly 100 determines whether the captured image is clear through a controller provided separately, and advances the lens assembly 103 by applying power to the coil 147 as necessary. Exercised. In this case, the controller may be installed in the assembly 102 on which the image sensor 121 is mounted. In addition, the controller compares a signal value for advancing and moving the lens assembly 103 with an actual position change value of the lens assembly 103 detected from the position sensor 149, and the lens assembly (if necessary). A signal for moving forward and backward 103 is generated again. Through such a control process, focusing of the camera lens assembly 100 may be precisely performed in the photographing process.

In the foregoing detailed description of the present invention, specific embodiments have been described. However, it will be apparent to those skilled in the art that various modifications can be made without departing from the scope of the present invention.

1 is a perspective view of a camera lens assembly according to a preferred embodiment of the present invention;

FIG. 2 is an exploded perspective view illustrating the camera lens assembly shown in FIG. 1;

3 is an exploded perspective view illustrating a camera lens assembly shown in FIG. 2 viewed from another direction;

4 is a perspective view illustrating a state in which the camera lens assembly illustrated in FIG. 2 is assembled;

5 is a cross-sectional configuration view showing the camera lens assembly shown in FIG. 1;

6 is a view for explaining a driving unit assembly of the camera lens assembly shown in FIG.

FIG. 7 is a three side view showing the drive assembly shown in FIG. 6;

FIG. 8 is a perspective view illustrating a state in which a lens assembly and a driving unit assembly of the camera lens assembly illustrated in FIG. 2 are combined; FIG.

Claims (10)

In the camera lens assembly, A main frame at least partially open in the optical axis direction; An image sensor disposed at one end of the main frame and aligned in the optical axis direction; A lens assembly accommodated in the main frame and moving forward and backward in the optical axis direction, the lens assembly having at least one lens; And And a driving unit assembly for moving the lens assembly back and forth in the optical axis direction. The driving unit assembly may include a magnetic body disposed on the lens assembly, a coil disposed on the main frame to face the magnetic body and generating an electric field as power is applied, and the coil being fixed on the main frame, between the magnetic body. And a yoke which is disposed to face the magnetic material, And when power is not applied to the coil, the lens assembly is stopped at a predetermined position by an attractive force between the magnetic material and the yoke. The camera lens assembly of claim 1, wherein the main frame has a second end thereof as an open end, and the camera lens assembly further includes a cover provided at the other end of the main frame. The camera lens assembly of claim 2, wherein the lens assembly moves forward and backward along the optical axis direction, and the cover limits the distance from the lens assembly to the image sensor within a predetermined distance. The method of claim 2, A binding piece extending from the cover; A binding hook formed by cutting a portion of the binding piece; Binding grooves formed in the main frame; And Further provided with a hook groove formed in a portion of the binding groove, And when the cover is coupled to the main frame, the binding piece is engaged with the binding groove and the binding hook is engaged with the hook groove, respectively. 2. The camera lens assembly of claim 1, wherein when no power is applied to the coil, the lens assembly stops at a position where the center of the magnetic body faces the center of the yoke. The lens assembly of claim 1, wherein when no power is applied to the coil, the lens assembly moves closer to the image sensor due to an attraction force between the magnetic material and the yoke, but is stopped by interfering with a portion of the main frame. Camera lens assembly. 7. The method of claim 6, wherein a portion of the yoke is bent to extend around the coil such that the attractive force between the bent portion of the yoke and the magnetic body moves the magnetic body and the lens assembly close to the image sensor. Camera lens assembly. 8. The camera lens assembly of claim 7, further comprising an evacuation groove formed in the main frame, wherein the bent portion of the yoke is received in the evasion groove. According to claim 1, A guide member provided in the driving unit assembly and extending along the optical axis direction; A support member provided in the lens assembly and extending along the optical axis direction; And Further comprising balls provided between the guide member and the support member, The support member is disposed facing the guide member, the camera lens assembly, characterized in that to maintain the spaced apart from the guide member by the balls. The camera lens assembly of claim 1, further comprising a position sensor installed on the main frame while being surrounded by the coil, wherein the position sensor detects a position of the magnetic material.

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