KR100736486B1 - Aperture Shutter Device for Small Cameras - Google Patents

Abstract

An aperture shutter device of a miniature camera according to the present invention includes a lens assembly including one or more lenses for acquiring an image of a subject, an image sensor for converting the image passing through the lenses into an electrical signal, and the image sensor. A miniature camera comprising a peripheral circuit portion, the light passing hole is formed in the center of the light is formed, the base is attached to the coil for controlling the aperture and shutter operation on one side left / right; An aperture shutter driver mounted on an outer periphery of the light passing hole of the base and rotating on one side with a magnet facing the coil; A plurality of shutter membranes axially supported by the base and connected to the aperture shutter driver, the shutter membranes flowing in a staggered direction according to a rotational movement of the aperture shutter driver to open and close the light passing holes; Light passing hole is formed in the center, characterized in that it comprises a cover formed with a plurality of slits on the left / right.

Camera, shutter, aperture, camera module

Description

Iris and shutter apparatus of camera

1 is a block diagram showing a compact camera structure.

2 is a conceptual diagram for applying a plurality of optical systems to FIG.

Figure 3 is a perspective view of the aperture shutter device of a small camera according to an embodiment of the present invention.

4 is a coupled state of FIG. 3.

5 is an exploded perspective view of FIG. 3.

6 is a view showing an open state of the light passing hole of the aperture shutter device according to the present invention.

7 is a view showing a state in which the light passing hole of the aperture shutter device according to the invention is closed.

8 and 9 are views showing the opening and closing operation of the aperture shutter device according to the invention.

10 is a view showing another installation position of the magnetic material according to the present invention.

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

110 ... Base 111 ... Light Pass

115 ... fixed link 121,122 ... coil

130 Aperture shutter drive 131 Magnet

132 ... Link 141,142 ... Shutter curtain

150 ... cover 143,153 ... fixed link slit

144 movable link slit 152 movable link guide slit

The present invention relates to a small camera mounted on a portable terminal and the like, in particular by adjusting the amount of light by a mechanical shutter and aperture, thereby improving image quality, miniaturization and low power, and applying to a portable terminal. The aperture shutter device of the present invention.

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 (personal digital assistants) 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 capabilities, high-end digital camera modules (digital) Installation of camera modules is becoming more and more common. With the development of various technologies to support this, a mega pixel image sensor is used in a small digital camera mounted on a portable terminal, so that optical zoom and auto focus functions can be used. In addition, the importance of the mechanical shutter (mechanical shutter) and mechanical iris (mechanical iris) function is becoming more important.

1 is an exploded perspective view showing the structure of a general compact camera.

Referring to FIG. 1, a configuration includes a lens group assembly 10 including one or more lenses, a case 20, an image sensor 30, and a peripheral circuit board 40 including peripheral circuits.

The lens group assembly 10 includes one or more lenses therein and is assembled to the case 20. The image sensor 30 and the peripheral circuit board 40 are provided below the case 20. The image sensor 30 detects an electrical signal from an optical signal passing through the lens, and is composed of a CMOS or CCD image sensor.

However, with the recent use of megapixel image sensors in digital camera modules mounted on portable terminals, many lens group assemblies, optical zoom, and auto focus adjustments have been added to provide high quality image acquisition and additional convenience functions. The module which added the (auto focus control) function is employ | adopted. FIG. 2 is a configuration in which a plurality of optical systems 11 and 12 are disposed between the image sensor 30 and the lens group assembly 10 to perform optical zoom and autofocus functions.

In the smallest 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. In the case of moving the movable part such as the lens group by the driver for the rotational motion of the back, there are a number of parts, the structure is complicated, and the volume is large due to the size of the motor.

In the image sensor, two methods of operating a charge-coupled device (CCD) include an interlaced scan and a progressive scan. The interlaced method scans an image twice in a manner used in the 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 obtain 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, there is an active development of a technology for employing a mechanical shutter.

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

In addition, by adopting a mechanical aperture, it can be useful to obtain a clear picture with a suitable exposure value with a mechanical shutter by adjusting the amount of incoming light, it is possible to adjust the depth of field, photographers like ordinary cameras Photographs of various moods that reflect the subjectivity of the camera can be obtained from the compact camera module.

In addition, the camera adopting the 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, and by tightening the aperture, the camera prevents light from entering the periphery of the lens. By utilizing the light in the center of the lens mainly in the image, it is possible to obtain a clear picture with little 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.

A first object of the present invention is to provide an aperture shutter device of a small camera capable of providing a mechanical aperture and shutter function to the small camera.

It is a second object of the present invention to provide an aperture shutter device for a small camera that enables the mechanical aperture and shutter function to be applied to a small camera module optical system.

A third object of the present invention is to integrate a mechanical aperture and a shutter so that the camera module can be reduced in weight and size.

Aperture shutter device of a compact camera according to the present invention for achieving the above object,

A compact camera comprising a lens assembly comprising one or more lenses for acquiring an image of a subject, an image sensor for converting the image passing through the lenses into an electrical signal, and a peripheral circuit portion of the image sensor,

A base having a light passing hole through which light passes through the center portion, and having a coil attached to one side of the left and right side to control the aperture and shutter operation;

An aperture shutter driver mounted on an outer periphery of the light passing hole of the base and rotating on one side with a magnet facing the coil;

A plurality of shutter membranes axially supported by the base and connected to the aperture shutter driver, the shutter membranes flowing in a staggered direction according to a rotational movement of the aperture shutter driver to open and close the light passing holes;

Light passing hole is formed in the center, characterized in that it comprises a cover formed with a plurality of slits on the left / right.

Preferably, the base has a guide rib formed on the outer periphery of the light passing hole in the center to support one side of the aperture shutter drive unit; A seating groove in which the other side of the aperture shutter driving unit is seated; A fixed link formed at left and right sides of the light passing hole to axially support the shutter film; Coils are attached to one side of the left and right sides and include an open groove that enables rotation of the aperture shutter driver.

Preferably, the aperture shutter driving unit and the cylindrical head portion formed with a light passing hole in the central portion; A movable link formed on the left and right sides of the head portion for rotating the shutter film; And a tail part having a magnet attached to the other side so as to face the coil.

Preferably, the shutter film includes a movable link slit through which the movable link penetrates at a central portion thereof, and a fixed link slit through which the fixed link penetrates outside the movable link slit, and is symmetrically opposed to each other.

Preferably, a plurality of dimples are formed in the seating recess of the base to be spaced apart from the bottom surface according to the seating of the aperture shutter driver.

Preferably, the cover or base one side is characterized in that it comprises a magnetic material that is opposed to the magnet, and generates an attraction force with the magnet when the current is not supplied to the coil to stop the aperture shutter drive unit.

The small camera aperture and shutter device configured as described above will be described with reference to the accompanying drawings.

3 is a perspective view illustrating a camera aperture and shutter device according to a preferred embodiment of the present invention, and FIG. 4 is a combined state diagram of FIG. 3.

3 and 4, a light passing hole 111 in a central portion thereof and a fixing link 115 formed at left and right sides thereof, and a base 110 mounted with coils 121 and 122 at one left and right side thereof; An aperture shutter driver 130 having a movable link 132 for diaphragm and shutter functions and having a magnet 131 opposed to the coils 121 and 122 at one central portion thereof; The shaft 110 is supported by the fixing link 115 of the base 110 and is axially rotated by the movable link 132 of the aperture shutter driver 130. The plurality of shafts are alternately rotated in order to open and close the light through hole 111. A plurality of shutter films 141 and 142; It is a configuration including a cover 150 formed with a light passing hole 111 for light passing through the center.

Referring to the accompanying drawings, the operation of the aperture shutter device of the small camera according to the embodiment of the present invention as described above is as follows.

First, referring to FIG. 3, the base 110 and the camera module cover 150 are coupled to each other, and include a light passing hole 111 through which light passes through a central portion thereof. 121, 122 are mounted. Through the VCM method using the magnets (not shown) installed in the coil (121, 122) and the inner movable part to drive the aperture shutter drive unit (not shown) located on one side of the light passing hole 111, the light passing hole 111 Can be opened and closed. The aperture shutter device opens and closes the aperture shutter 111 by using an electromagnetic force generated between the coils 121 and 122 and a magnet (not shown). The aperture shutter driving device may be used as a part of the lens group assembly or as a part of an ultra-compact camera structure to play a role of controlling image light quantity and blocking an image, and to reduce the number of mechanical shutters and aperture structures using a conventional motor. It has the advantage of using parts and taking up less volume. The aperture shutter device of the present invention is applied to a portable terminal or the like.

5 is an exploded perspective view of FIG. 3.

Referring to FIG. 5, the cover 150 includes a base 110, an aperture shutter driver 130, and a plurality of shutter films 141 and 142. A light passing hole 111 is formed in the center of the base 110, the aperture shutter driver 130, and the cover 150.

A movable link guide slit 152 to which the movable link 132 is coupled to the left and right centers of the cover 150 is formed, and a fixed link slit to which the fixed link 115 is coupled to the outer side of the movable link guide slit 152 ( 153 is formed. In addition, the coil insertion holes 155 and 156 exposing the coils 121 and 122 are formed at one side left and right of the cover 150.

The base 110 is formed with a guide rib 112 for guiding the head portion 133 of the aperture shutter driver 130 on the outer periphery of the light passing hole 111, the head of the aperture shutter driver 130 A seating groove 113 on which the part 133 is seated is formed, and a plurality of dimples 114 are formed on the head seating groove 113. The fixing link 115 protrudes upward in the center left and right of the base 110, and the tail part 134 of the aperture shutter driver 130 flows on one side thereof and the coils 121 and 122 may be mounted. Open grooves 117 are formed.

The aperture shutter driver 130 is largely divided into a head part 133 and a tail part 134. The head part 133 is formed in a cylindrical shape and a movable link 132 protrudes from the left and right sides. The magnet 131 is mounted to the tail part 134 so as to face the coils 121 and 122.

The shutter membranes 141 and 142 are stacked on top of each other, and are composed of upper and lower shutter membranes 141 and 142, and fixed link slits 143 through which the fixed link 115 penetrates are formed at an end thereof, and the movable link is formed at the center thereof. A movable link slit 144 is formed through which 132 penetrates.

In the coupling structure of the aperture shutter device as described above, the coils 121 and 122 are attached to the left and right sides of the base 110, respectively, and the aperture shutter driving unit is disposed outside the peripheral guide rib 112 of the light passing hole 111. The head portion 133 of the 130 is seated. Accordingly, the bottom surface of the head portion 133 of the aperture shutter driver 130 is seated in the head seating groove 113, and is maintained at a predetermined distance by the dimple 114 formed in the seating groove 113. . At this time, the magnet 131 located in the tail portion 134 of the aperture shutter driver 130 is opposed to the coils 121 and 122.

The plurality of shutter films 141 and 142 are seated on the left and right sides of the base 110 and the aperture shutter driver 130, respectively. Accordingly, the fixed link 115 passes through the fixed link slit 143 of the shutter films 141 and 142, and the movable link 132 passes through the movable link slit 144 of the shutter films 141 and 142. The films 141 and 142 face each other with respect to the light passing hole 111.

Here, the base 110 has a step portion 116 in which the head mounting groove 113 and the shutter films 141 and 142 are seated, so that the shutter films 141 and 142 are axially rotated on the aperture shutter driver 130. do.

In addition, the cover 150 is rotatably guided through the movable link 132 through the movable link guide slit 152 formed at the left / right of the light passing hole 111 in the center, and the left / right of the movable link guide slit 152. The fixing link 115 passes through the fixing link slit 153 formed at the right side. In addition, the coils 121 and 122 are exposed to the coil insertion holes 155 and 156 formed at the left and right sides of the cover 150.

Referring to the operation of the aperture shutter device, the aperture shutter drive unit 130 rotates with respect to the center of the light passing hole 111 by the electromagnetic force generated between the coils 121 and 122 and the magnet 131. The movable link 132 formed on the left and right of the head of the shutter driver 130 is axially assembled with the movable link slit 144 formed on the shutter films 141 and 142 to generate a rotational movement of the shutter films 141 and 142. . In this case, since the shutter membranes 141 and 142 are axially coupled to the fixing link 115 provided in the base 110, which is a fixed portion, the shutter films 141 and 142 rotate around the fixing link 115. It adjusts the amount of image light and adjusts the time that the image is exposed to the image sensor, and serves as a shutter and an aperture.

6 and 7 illustrate an aperture shutter operation according to the present invention.

6 is a state in which the light passing hole 111 is opened, and when the current is not applied to the coils 121 and 122, the aperture shutter driver 130 is stopped and connected to the movable link 132 of the aperture shutter driver 130. And the lower shutter films 141 and 142 face each other while the light passing holes 111 are opened.

In this state, when the current flows through the coils 121 and 122, the light passing holes 111 are closed as shown in FIG. 7. That is, when a current is applied to the coils 121 and 122 in a predetermined direction, a predetermined size, and for a predetermined time, an electric magnetic force is generated between the coils 121 and 122 and the magnet 131, and the magnet 131 and the aperture shutter corresponding to the movable part are generated. The driver 130 rotates. At the same time, the upper and lower shutter films 141 and 142 connected to the movable link 132 of the iris shutter driver 130 rotate alternately with each other, thereby closing the light passing hole 111. In addition, by controlling the magnitude, time, and direction of the current flowing through the coils 121 and 122, the magnitude and direction of the force acting on the magnet 131 may be adjusted to control the opening and closing degree of the light passing hole.

In other words, the aperture shutter driver 130 rotates due to the electromagnetic force generated between the coils 121 and 122 and the magnet 131, and the shutter membranes 141 and 142 which are axially assembled with the aperture shutter driver 130 and the movable link are provided. According to the rotational movement of the aperture shutter driver 130, the rotational movements in opposite directions with respect to the fixing link 115 of the base are performed. Accordingly, the plurality of shutter membranes perform the aperture and shutter operations to symmetrically open and close the light passing holes 111.

Meanwhile, by adjusting the shaft assembly position between the aperture shutter driver 130, the movable link 132 of the shutter curtain, and the fixed link 115, the actual displacement of the aperture shutter driver 130 and the movable displacement of the end of the fixed link 115 are adjusted. The ratio can be adjusted based on the principle of the lever, and in the driving method, the degree of opening and closing of the light passing hole can be controlled by changing the magnitude, time, and direction of the current flowing through the driving coil.

The operation of the aperture shutter device having the above configuration will be described below.

In order to acquire an image of the subject in the camera apparatus, the aperture shutter apparatus opens all of the light passing holes 111 so that light passes well through the lens assembly so that the image sensor brightly captures the image of the subject.

At this time, the control unit (not shown) of the camera device does not apply current to the coils 121 and 122 wound on both sides of the base 110. In this case, the plurality of shutter films 141 and 142 are maintained in the open state of the light passing hole 111 as shown in FIGS. 6 and 8.

Meanwhile, when the image of the subject is photographed by the camera device, the aperture shutter driver 130 and the shutter films 141 and 142 are moved as shown in FIGS. 7 and 9 to close the light passing hole 111 to receive light incident on the lens group. It is blocked momentarily.

In this process, first, when a predetermined amount of power and a predetermined size are applied to the coils 121 and 122 from a controller (not shown), the magnets 131 may be formed by a total magnetic force generated between the magnets 131 and the coils 121 and 122. In addition, the aperture shutter driver 130 is operated in the rotational direction.

Accordingly, the shutter films 141 and 142 rotate in opposite directions along the movable link slit 144 and the guide slit 152 coupled to the movable link 132 of the aperture shutter driver 130, and the upper and lower shutter films ( 141 and 142 are collected at both sides of the light passing hole 111 to close the light passing hole 111.

In this manner, since the two shutter films 141 and 142 are simultaneously collected from both sides of the light passing holes 111, the light flowing into the light passing holes 111 is blocked at a high speed. The image quality of the still image of the camera depends on the speed of the aperture shutter device. Since the moving speed of the shutter unit is maximized due to the simple structure, the still image of the camera can be captured by the image sensor.

Meanwhile, reverse current is applied to the left and right coils 121 and 122 to open the light passing hole 111 after the photographing of the subject. Accordingly, a counter electromotive force is generated between the coils 121 and 122 and the magnet 131 so that the aperture shutter driver 130 rotates in the opposite direction together with the magnet 131.

Accordingly, the movable link 132 is pushed in the opposite direction along the movable link slit 144 of the pair of shutter films 141 and 142 and the guide slit 152 by rotating in the opposite direction about the fixed link 115. Accordingly, the pair of shutter films 141 and 142 open the light passing holes 111. When the light passage hole 111 is opened, the control unit blocks the current applied to the coils 121 and 122. At this time, the aperture shutter driver 130 is positioned along with the magnet 131 due to the attraction between the magnetic body 160 and the magnet 131.

In general, a driver using electromagnetic force between the coils 121 and 122 and the magnet 131 has a disadvantage in that it continuously consumes power by continuously applying current to maintain a constant displacement. As described above, the magnetic body 160 is added to a part of the aperture shutter device, and the magnet 131 and the aperture shutter driver 130 are driven by the attraction force generated between the magnetic body 160 and the magnet 131 even when a current is not applied to the coils 121 and 122. ) Contacts the cover 150 or the base 110, which are the fixed structures of the shutter films 141 and 142, and performs a latching operation to maintain a constant displacement by the contact frictional force.

As shown in FIG. 8, when no force is generated between the driving coils 121 and 122 and the magnet 131 because there is no applied current in the coils 121 and 122, an attraction force generated between the magnet 131 and the magnetic body 160 may be generated. The frictional force F3 is generated by F1). This adds a latching function that maintains the current position even without an applied current, and particularly provides a latching function that maintains the current position even when unwanted driving force F2 occurs due to disturbance such as gravity. In this case, when a current is applied to the coils 121 and 122, a driving force is generated by the coil and the magnet, and a driving force F4 is greater than the friction force F3 generated by the attraction force F1 between the magnet 131 and the magnetic body 160. In this case, the aperture shutter driver 130 moves, and the shutter membranes 141 and 142 cause a movement of opening and closing the light passing hole 111. In addition, the opening and closing displacement at this time can be controlled by adjusting the applied current magnitude and time, the opening and closing direction can be adjusted by changing the direction of the applied current.

Referring to FIG. 10, the magnetic body 161 for the latching function may be formed above the cover 150, which is an aperture structure, or under the base 110, thereby causing frictional force generated by the attraction force between the magnet and the magnetic body 161. The latching function can be performed to fix the position when no current is applied.

On the other hand, in the present invention, even if the installation position of the magnet and the coil are interchanged with each other, the aperture shutter driving unit functions the same.

So far, the present invention has been described with reference to the preferred embodiments, and those skilled in the art to which the present invention pertains to the detailed description of the present invention and other forms of embodiments within the essential technical scope of the present invention. Could be implemented. Here, the essential technical scope of the present invention is shown in the claims, and all differences within the equivalent range will be construed as being included in the present invention.

According to the aperture shutter device of a small camera according to the present invention, unlike the camera module that implements the shutter and aperture by a driver using a conventional step motor or an electromagnet, a linear driver of VCM (Voice Coil Motor) type is used. It is suitable for light weight.

In addition, the camera module according to the present invention can provide improved image quality by adding a latching function and adding a mechanical shutter and aperture function while occupying a minimum space in the existing micro camera module.

In addition, by opening a portion of the base to install the aperture shutter driver, there is an effect that can reduce the thickness of the camera module.

In addition, it is expected to be suitable for various portable devices such as PDA and mobile phone by adding a low power function by providing mechanical shutter and aperture.

Claims (6)

A compact camera comprising a lens assembly comprising one or more lenses for acquiring an image of a subject, an image sensor for converting the image passing through the lenses into an electrical signal, and a peripheral circuit portion of the image sensor, A base having a light passing hole through which light passes through the center portion, and having a coil attached to one side of the left and right side to control the aperture and shutter operation; An aperture shutter driver mounted on an outer periphery of the light passing hole of the base and rotating on one side with a magnet facing the coil; A plurality of shutter membranes axially supported by the base and connected to the aperture shutter driver, the shutter membranes flowing in a staggered direction according to a rotational movement of the aperture shutter driver to open and close the light passing holes; The aperture shutter device of the compact camera, characterized in that it comprises a cover formed with a light passing hole in the center, a plurality of slits formed on the left and right. The method of claim 1, The base may include a guide rib formed at an outer periphery of the light passing hole at the center to support one side of the aperture shutter driver; A seating groove in which the other side of the aperture shutter driving unit is seated; A fixed link formed at left and right sides of the light passing hole to axially support the shutter film; A coil is attached to one side of the left / right, the aperture shutter device of a small camera, characterized in that it comprises an open groove to enable the rotation of the aperture shutter drive unit. The method of claim 2, The aperture shutter driving unit and the cylindrical head portion formed with a light passing hole in the central portion; A movable link formed on the left and right sides of the head portion for rotating the shutter film; And a tail part having a magnet attached to the other side so as to face the coil. The method of claim 3, wherein The shutter film includes a movable link slit through which the movable link penetrates at a central portion thereof, and a fixed link slit through which the fixed link penetrates outside the movable link slit, and is symmetrically opposed to each other. The method of claim 2, The shutter of the compact camera, characterized in that a plurality of dimples are formed to be spaced apart from the floor according to the seating groove of the aperture shutter drive unit. The method of claim 1, One side of the cover or base is opposite to the magnet, when the current is not supplied to the coil to generate a attraction force with the magnet to stop the aperture shutter drive unit further comprises a magnetic shutter of the compact camera, characterized in that Device.

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