JP2007056678A - Air pump and camera module using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air pump in which a drive part is formed integrally with a drive source and a size is reduced. <P>SOLUTION: This air pump comprises a container 10 having an air flow passage 11 and at least two hole parts 12, 12 communicating with the outside and the drive part 20 installed in the container 10, sucking air from one hole part 12a, and discharging air from the other hole part 12b. The drive part 20 comprises a plurality of bag parts 21 installed on the inner surface of the container 10 and filled with a liquid 23 and heating elements 22 fitted to the lower parts of the bag parts 21. The bag parts 21 and the heating elements 22 are installed along the direction of the air flow passage 11. The heating elements 22 are heated in order from the hole part 12a side for sucking the air toward the hole part 12b side for discharging the air. Consequently, the corresponding bag part 21 is inflated by boiling in order the liquid 23 in the bag parts 21 to discharge the air in the flow passage 11 to the discharge hole part 12b side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air pump that sucks and discharges air and a camera module using the same, and more particularly to an air pump that drives using a boiling phenomenon due to heating and a camera module using the same.

2. Description of the Related Art Conventionally, driving devices that move a camera lens in the optical axis direction for automatic focus adjustment, zooming, and the like are known. One is a combination of gears and a motor that aligns the lens with high precision. In addition, there is also known a method in which the air chambers before and after the lens are sealed and the lens is moved by changing the air pressure of each air chamber by a driving source. In this case, an air cylinder, a diaphragm or a rotary pump is used as a drive source.
JP 2004-258111 A

  Particularly in recent years, there has been a strong demand for downsizing digital cameras and the like, and it is also necessary to downsize lens driving devices in cameras. However, all of the conventional lens driving devices require an external driving source, so that it is difficult to reduce the size of the device. Therefore, an air pump as a drive device in which a drive unit and a drive source are integrated has been desired.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an air pump that can be downsized by integrating a drive unit and a drive source, and a camera module using the air pump.

In order to solve the above problems, an air pump according to the present invention includes a container having at least two holes communicating with an air flow path and the outside, and sucks air from one of the holes provided in the container. An air pump including a drive unit that discharges air from the other hole,
The drive unit includes a plurality of bag portions provided on the inner surface of the container and filled with liquid, and heating elements respectively provided at the lower portions of the bag portions,
A plurality of the bag portions and heating elements are provided along the air flow path direction, and the heating elements generate heat in order from the hole suction side to the discharge hole side, The liquid is boiled in order to expand the corresponding bag portion, and is sent out to the hole portion side for discharging the air in the flow path.

  In addition, the air pump according to the present invention stops the heat generated in the bag portion by sequentially stopping the heat generation in the heat generating state from the hole portion side for sucking air toward the hole portion side for discharging air. The liquefaction is sequentially performed, the corresponding bag portion is contracted, and the air is sucked from the hole portion for sucking air into the flow path.

Further, in the air pump according to the present invention, the heating element sequentially generates heat from the hole side for sucking air toward the hole side to be discharged and inflates the corresponding bag part in order to perform an air discharging operation. Stop the heat generation of the heating element on the side of the hole that sucks in from the heating element that has started to generate heat, contract the corresponding bag part in order, and perform the air suction operation,
When the bag portion at the hole side end portion for discharging air is inflated, the heating element at the hole side end portion for sucking air generates heat, and when the bag portion at the hole side end portion for sucking air expands, the air is discharged. The heat generating body at the end portion on the hole side to be discharged is stopped, and the air discharge operation and the suction operation are restarted.

Furthermore, in the camera module according to the present invention, the lens is disposed in the lens chamber, and the lens chamber is divided into a first chamber and a second chamber sealed by the lens, and the first chamber and the second chamber are divided. In the camera module that moves the lens in the direction of the optical axis by the pressure difference,
The first chamber and the second chamber of the lens chamber communicate with the holes of the air pump according to any one of claims 1 to 3, and the first chamber and the second chamber are operated by the operation of the air pump. The lens is moved in the direction of the optical axis by generating a difference in atmospheric pressure.

  According to the air pump of the present invention, the air pump includes a plurality of bag portions provided on the inner surface of the container and filled with a liquid, and heating elements provided at the lower portions of the bag portions, respectively. A plurality of heating elements are provided along the flow path direction, and the heating element sequentially generates heat from the hole side for sucking air toward the hole part side for discharging, thereby boiling the liquid in the bag part in order to form the corresponding bag part. Since the air pump in which the drive unit and the drive source are integrated can be obtained by inflating and sending the air in the flow path to the side of the hole that discharges the air, the size can be reduced.

  Further, according to the air pump of the present invention, the heating element in a heat generating state stops the heat generation in order from the hole side for sucking air toward the hole side for discharging air, so that the gas boiled in the bag part is removed. The suction operation can be easily performed by sequentially liquefying and contracting the corresponding bag portion and sucking air from the hole for sucking air into the flow path.

  Further, according to the air pump of the present invention, the heating element generates heat in order from the hole side for sucking air toward the hole side for discharging, and inflates the corresponding bag part in order to perform the air discharging operation. The heat generation of the heat generating element on the hole side that sucks in from the heat generating element that has started to generate heat is sequentially stopped, the corresponding bag part is contracted in order, the air is inhaled, and the bag part on the hole side end that discharges air The heat generating element at the hole side end that sucks air in the expanded state generates heat, and when the bag part at the hole side end that sucks air expands, the heat generating element at the hole side end that discharges air In addition, the suction operation and the discharge operation can be performed simultaneously by restarting the air discharge operation and the suction operation, so that the amount of suction and discharge per hour can be increased and the space between the holes can be increased. Air is never opened Reverse flow can be prevented.

  Furthermore, according to the camera module of the present invention, the first chamber and the second chamber of the lens chamber communicate with the holes of the air pump, respectively, and the pressure difference between the first chamber and the second chamber is caused by the operation of the air pump. By causing the lens to move in the optical axis direction, the screw holder and the winding portion are not required in the lens holder and the size can be reduced as compared with the case where a stepping motor is used for driving the lens. it can. In addition, since the air pump does not require an external drive source, the entire lens module can be reduced in size.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of the air pump in the present embodiment, and FIG. 2 is a longitudinal sectional view of the air pump. As shown in FIG. 1, the air pump in this embodiment includes a container 10 having an air flow path 11 therein and a drive unit 20 provided in the flow path 11, and is formed in the container 10. Air is sucked from one of the two holes 12, 12 communicating with the outside, and air is discharged from the other.

  The driving unit 20 includes a plurality of bag portions 21 provided on the inner surface of the flow path 11 and filled with a liquid 23 inside, and heating elements 22 provided below the respective bag portions 21. The bag portion 21 is arranged in parallel along the direction of the flow path 11 and has substantially the same width as the width of the flow path 11.

  As shown in FIG. 2, each heating element 22 is embedded in the bottom surface of the flow path 11, and a bag portion 21 filled with a liquid 23 is provided so as to cover it. The heating element 22 is composed of a resistor that generates heat when energized, and the liquid 23 in the bag portion 21 can be heated and boiled by generating heat.

  Next, the operation of the air pump will be described. FIG. 3 is a longitudinal sectional view of the air pump, showing the air suction and discharge operations. The air pump operates in the order of FIG. 3A to FIG. 3F with time. In this example, the right hole 12 in the figure is an air inlet 12a, and the left hole 12 in the figure is an air outlet 12b.

  FIGS. 3A to 3C show the air discharge operation. First, as shown in FIG. 3 (a), the heating element 22a at the end on the suction port 12a side is energized, and the liquid 23 in the bag portion 21a corresponding thereto is heated and boiled to generate bubbles 24. As a result, the bag portion 21 a rapidly expands and closes the flow path 11. In this state, air in the flow path 11 on the discharge port 12b side of the inflated bag portion 21a is discharged toward the discharge port 12b in the following process.

  Next, as shown in FIG. 3B, the heating elements 22b, 22c, 22d, and 22e are energized in order from the suction port 12a side to the discharge port 12b side to generate heat, and the bag portions 21b, 21c, 21d, and 21e. Are inflated in order. Then, since the flow path 11 is closed in order from the suction port 12a side to the discharge port 12b side, the air in the flow channel 11 is sent out toward the discharge port 12b side.

  When all the bag portions 21 are inflated as shown in FIG. 3C, the air discharge operation from the flow path 11 is completed. At this time, in order to maintain the bubbles 24 in the bag portion 21, energization is continued as it is to each heating element 22, but the amount of heat generated for maintaining the bubbles 24 is the amount of heat generated for boiling the liquid 23. Therefore, the electric power supplied to the heating element 22 may be reduced after the liquid 23 in the bag portion 21 boils.

  Next, an air suction operation is performed. As shown in FIG. 3D, the energization to the heating element 22a at the end on the suction port 12a side is first stopped after the discharge operation is completed. As a result, the bubbles 24 in the bag portion 21 a corresponding to the heating element 22 a that has been de-energized liquefy and become the liquid 23. As a result, the bag portion 21 contracts rapidly and the state of closing the flow path 11 is released and the bag portion 21 is opened. Air is sucked into the portion where the channel 11 is opened from the suction port 12a.

  Further, as shown in FIG. 3 (e), energization of the heating elements 22b, 22c, 22d, and 22e is stopped in order from the suction port 12a side to the discharge port 12b side, and the bag portions 21b, 21c, 21d, and 21e are connected. Shrink in order. Then, since the flow path 11 is opened sequentially from the suction port 12 a side toward the discharge port 12 b side, air is guided into the flow path 11 from the suction port 12 a. Eventually, as shown in FIG. 3 (f), all the bag portions 21 are contracted and the state from the suction port 12a to the discharge port 12b is communicated. After this state, air can be continuously sucked and discharged by restarting the discharge operation as shown in FIG.

  Next, an operation example when performing the suction and discharge operations simultaneously will be described. FIG. 4 is a diagram showing air suction and discharge operations in this example. In this case, the operation is performed in the order of FIG. 4 (a) to FIG. 4 (f). Before operation, the state is the same as that shown in FIG. When the operation starts, first, as shown in FIG. 4 (a), the heating element 22a at the end on the inlet 12a side and the heating element 22b adjacent thereto are energized to generate heat, and the corresponding bag parts 21a and 21b are respectively Inflate.

  Subsequently, as shown in FIGS. 4B and 4C, the heating element 22 is sequentially heated toward the discharge port 12b, and at the same time, the energization of the heating element 22 on the suction port 12a side is sequentially released. . Accordingly, there are always two bag portions 21 that expand and block the flow path 11, so that the air is sucked into the flow path 11 on the suction port 12 a side and the flow path 11 on the discharge port 12 b side. The inside air is sent out, and the suction operation and the discharge operation are performed simultaneously.

  As shown in FIG. 4D, the air suction operation and the discharge operation are completed in the state in which the bag portion 21e at the end on the discharge port 12b side is inflated. If the bag portion 21e is contracted as it is, air flows backward from the discharge port 12b side to the suction port 12a side. Therefore, the bag portion 21a at the end portion on the suction port 12a side is inflated as shown in FIG. 11 is closed, and in this state, as shown in FIG. 4F, the bag portion 21e at the end on the discharge port 12b side is contracted. Thereafter, the operation returns to the state of FIG.

  Thus, by simultaneously performing the suction operation and the discharge operation of the air in the flow path 11, it is possible to increase the amount of suction and discharge per time. Further, since the flow path 11 is not opened from the suction port 12a to the discharge port 12b, backflow of air can be prevented.

  In the description of FIGS. 3 and 4, the right hole 12 in the drawing is the suction port 12a, and the left hole 12 in the drawing is the discharge port 12b. However, any hole 12 may be the suction port or the discharge port. . If the order of energization with respect to the heating element 22 is changed from the opposite side, the hole 12 on the left side in the drawing can be used as the suction port, and the hole 12 on the right side in the drawing can be used as the discharge port. In addition, the operation of the bag portion 21 is not necessarily performed in order from the end portion, and the operation may be started from the intermediate bag portion 21.

  Furthermore, in the present embodiment, the hole 12 is provided at both ends of the flow path 11, but the hole 12 is further provided at the intermediate part of the flow path 11, which is used as an inlet, and the left and right holes 12, 12. It is also possible to operate the bag portion 21 so as to selectively discharge the water.

  Next, a camera module using the air pump of this embodiment will be described. FIG. 5 shows a schematic diagram of a camera module using the air pump of the present embodiment. As shown in this figure, the camera module arranges the lens 3 in the lens chamber 2, and the lens chamber 2 is divided into a first chamber 2a and a second chamber 2b that are sealed by the lens 3, respectively. The second chamber 2b communicates with the holes 12 and 12 of the air pump 1, respectively.

  Further, the lens chamber 2 is provided with a cover glass 6 on the outer side, and an infrared blocking filter 7 is provided on the surface facing the cover glass 6. Further, an image sensor 8 is disposed on the optical axis of the lens 3 so that light from the cover glass 6 is imaged on the image sensor 8 through the lens 3.

  The lens 3 is held by a cylindrical holder 4. Grease 5 is provided between the holder 4 and the wall surface of the lens chamber 2, and the lens 3 held by the holder 4 is movable in the optical axis direction. It is said. As described above, since the first chamber 2a and the second chamber 2b of the lens chamber 2 are sealed and connected to the air pump 1, the air pump 1 causes a pressure difference between the first chamber 2a and the second chamber 2b. The lens 3 can be moved in the direction of the optical axis.

  The air pump 1 includes the drive unit 20 in the container 10 as described above, and the drive unit 20 includes a bag portion 21 and a heating element 22, and also serves as a drive source. There is no need to provide it separately, and the driving device for the lens 3 can be reduced in size. Further, since it is not necessary to provide a screw part or a winding part in the holder 4 as compared with the case where a stepping motor is provided, the lens chamber 2 can be reduced in size.

  In the present embodiment, the lens 3 is held by the holder 4, and the holder 4 is configured to move in the lens chamber 2 via the grease 5. However, the lens 3 has the air pressure in the first chamber 2a and the second chamber 2b. It suffices if it is configured to be movable in the optical axis direction according to the difference. For example, the lens 3 is fixed to the wall surface of the lens chamber 2 via a diaphragm, and the atmospheric pressure difference between the first chamber 2a and the second chamber 2b. Thus, the lens 3 may be moved by bending the diaphragm.

It is a perspective view of the air pump in this embodiment. It is a longitudinal cross-sectional view of an air pump. It is the figure which showed the operation example of the air pump in the case of performing suction | inhalation and discharge separately. It is the figure which showed the operation example of the air pump in the case of performing suction and discharge simultaneously. It is a schematic diagram of the camera module using the air pump in this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air pump 2 Lens chamber 3 Lens 4 Holder 5 Grease 10 Container 11 Flow path 12 Hole 12a Inlet 12b Outlet 20 Drive part 21 Bag part 22 Heating element

Claims (4)

A container having at least two holes communicating with the air flow path and the outside, and a drive unit provided in the container for sucking air from one hole and discharging air from the other hole An air pump,
The drive unit includes a plurality of bag portions provided on the inner surface of the container and filled with liquid, and heating elements respectively provided at the lower portions of the bag portions,
A plurality of the bag portions and heating elements are provided along the air flow path direction, and the heating elements generate heat in order from the hole suction side to the discharge hole side, An air pump characterized in that the liquid is boiled in order to expand the corresponding bag portion and send it out to the hole side for discharging the air in the flow path.   The heating element in the heat generating state stops heat generation in order from the hole side for sucking air toward the hole side for discharging, thereby liquefying the gas boiled in the bag part in order and shrinking the corresponding bag part 2. The air pump according to claim 1, wherein air is sucked into the flow path from a hole for sucking air. The heating element sequentially generates heat from the side of the hole for sucking air toward the side of the hole for discharging, and inflates the corresponding bag part in order to perform air discharging operation. Stop the heat generation of the heating element on the part side in order and contract the corresponding bag part in order to inhale air,
When the bag portion at the hole side end portion for discharging air is inflated, the heating element at the hole side end portion for sucking air generates heat, and when the bag portion at the hole side end portion for sucking air expands, the air is discharged. 2. The air pump according to claim 1, wherein heat generation from the heating element at the end of the hole to be discharged is stopped and the air discharge operation and the suction operation are restarted. 3. A lens is arranged in the lens chamber, and the lens chamber is divided into a first chamber and a second chamber sealed by the lens, respectively, and the lens is moved in the optical axis direction by a pressure difference between the first chamber and the second chamber. In the camera module
The first chamber and the second chamber of the lens chamber communicate with the holes of the air pump according to any one of claims 1 to 3, and the first chamber and the second chamber are operated by the operation of the air pump. A camera module, wherein an atmospheric pressure difference is caused to move the lens in the optical axis direction.

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