JP2007193248A - Camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera module that can switch a distance between a lens and an imaging device with a simple and inexpensive configuration. <P>SOLUTION: The camera module includes a lens barrel 1 holding the lens 4, and a holder 2 movably holding the lens barrel 1 in an optical axis direction of the lens 4. The holder 2 includes a first reference plane 23, and a second reference plane 24, which are perpendicular to the moving direction of the lens barrel 1, and which are directed in an opposite direction to each other. The lens barrel 1 includes a first abutment surface 13 abutting the first reference plane 23, and a second abutment surface 14 abutting the second reference plane 24 with the axial movement of the lens 4. The holder 2 is connected with the lens barrel 1 through a bimetal 7. Also, the lens barrel 1 is positioned with respect to the holder 2 by switching an abutting state of the first abutment surface 13 with the first reference plane 23, and an abutting state of the second abutment surface 14 with the second reference plane 24 depending on the operation of the bimetal 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a camera module having a mechanism capable of changing the distance between a lens and an image sensor stepwise, and more particularly to a camera module that moves a lens in an optical axis direction by bimetal.

In a small camera module, a mechanism for switching between a normal shooting mode and a close-up shooting mode is known. This mechanism switches the distance between the lens and the image sensor. Conventionally, a screw is provided in each of the lens barrel that holds the lens and the holder that holds the lens barrel and is equipped with the image sensor. The lens barrel is moved in the optical axis direction of the lens with respect to the holder. An example of such a camera module is disclosed in Patent Document 1.
JP-A-10-104491

  However, when the distance between the lens and the image sensor is switched by rotating the screw, a mechanism such as a motor is necessary to automatically switch the distance, which hinders downsizing of the camera module and increases the cost. It was the cause.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a camera module that can switch the distance between a lens and an image sensor with a simple and inexpensive configuration.

In order to solve the above problems, a camera module according to the present invention is a camera module including a lens barrel that holds a lens and a holder that holds the lens barrel so as to be movable in the optical axis direction of the lens.
The holder includes a first reference surface and a second reference surface that are perpendicular to the moving direction of the lens barrel and are opposite to each other, and the lens barrel is moved in the optical axis direction of the lens. A first contact surface that contacts the reference surface and a second contact surface that contacts the second reference surface,
The holder and the lens barrel are connected via a bimetal, and according to the operation of the bimetal, the contact state between the first contact surface and the first reference surface, and the second contact surface The lens barrel is positioned with respect to the holder by switching the contact state with the second reference surface.

  The camera module according to the present invention is characterized in that the bimetal is provided so as to be suspended between an inner peripheral surface of the holder and an outer peripheral surface of the barrel.

  Furthermore, in the camera module according to the present invention, the bimetal is provided over substantially the entire circumference between the inner peripheral surface of the holder and the outer peripheral surface of the barrel, and a heating element is provided on the surface in a ring shape. It is constituted by being made.

  Furthermore, in the camera module according to the present invention, the holder has a flange portion on an outer peripheral surface holding the lens barrel, and at least one of an upper surface or a lower surface of the flange portion is any one of reference surfaces. It is configured as.

  In the camera module according to the present invention, the lens barrel has a recess on the inner peripheral surface over the entire periphery, and at least one of the upper surface or the lower surface of the recess is a contact surface that contacts the reference surface of the flange portion. It is configured as a feature.

In the camera module according to the present invention, the lens barrel is held by the holder, and the lens barrel is held in the first lens barrel so as to be movable in the optical axis direction of the lens. A second lens barrel that holds
The first lens barrel includes a first reference surface, a second contact surface, and a third reference surface and a fourth reference surface that are perpendicular to the moving direction of the lens barrel and are opposite to each other. And the second lens barrel has a third contact surface that contacts the third reference surface and a fourth contact surface that contacts the fourth reference surface as the lens moves in the optical axis direction. And
The first lens barrel and the second lens barrel are connected via a second bimetal, and the third abutting surface and the third reference surface are operated according to the operation of the second bimetal. The second lens barrel is positioned with respect to the first lens barrel by switching between a contact state and a contact state between the fourth contact surface and the fourth reference surface. It is configured.

  According to the camera module of the present invention, the holder and the lens barrel are connected via the bimetal, and the contact state between the first contact surface of the lens barrel and the first reference surface of the holder according to the operation of the bimetal. And switching the contact state between the second contact surface of the lens barrel and the second reference surface of the holder and positioning the lens barrel with respect to the holder, whereby the bimetal is interposed between the holder and the lens barrel. Since the position of the lens in the optical axis direction can be switched simply by providing the lens, the distance between the lens and the image sensor can be switched with a simple and inexpensive configuration.

  Further, according to the camera module of the present invention, the bimetal is provided so as to be suspended between the inner peripheral surface of the holder and the outer peripheral surface of the lens barrel, so that the configuration of the bimetal can be simplified.

  Furthermore, according to the camera module of the present invention, the bimetal is provided over substantially the entire circumference between the inner peripheral surface of the holder and the outer peripheral surface of the lens barrel, and a heating element is provided in a ring shape on the surface. As a result, a force can be applied to the lens barrel over the entire circumference, so that the lens barrel can be moved stably.

  Furthermore, according to the camera module of the present invention, the holder has a flange on the outer peripheral surface that holds the lens barrel, and at least one of the upper surface or the lower surface of the flange is any one of the reference surfaces. The reference plane can be configured with a simple configuration.

  According to the camera module of the present invention, the lens barrel has a recess extending over the entire inner peripheral surface, and at least one of the upper surface or the lower surface of the recess is a contact surface that contacts the reference surface of the collar portion. Thus, the contact surface can be configured with a simple configuration.

  According to the camera module of the present invention, the lens barrel is held in the holder, and the lens barrel is held in the first lens barrel so as to be movable in the optical axis direction of the lens and holds the lens inside. The first lens barrel and the second lens barrel are connected via the second bimetal, and the third of the second lens barrel is operated according to the operation of the second bimetal. Contact state between the contact surface and the third reference surface of the first lens barrel, and contact between the fourth contact surface of the second lens barrel and the fourth reference surface of the first lens barrel By switching the state, the second lens barrel is positioned with respect to the first lens barrel, so that the lens barrel is duplicated and each is positioned by the operation of the bimetal and the reference surface and the contact surface. Four patterns can be set for the position of the lens in the optical axis direction.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a cross-sectional view of the camera module in the present embodiment. As shown in this figure, the camera module in this embodiment includes a lens barrel 1 in which a lens 4 is housed, and a holder 2 that holds the lens barrel 1 so as to be movable in the optical axis direction of the lens 4. The element 5 is arranged on the substrate 3 provided on the upper surface. In the holder 2, a filter 6 that blocks infrared rays is provided between the lens 4 and the image sensor 5.

  The lens barrel 1 is formed in a substantially cylindrical shape, and a lens 4 is held on the inner peripheral surface, and a concave portion 12 is formed below the entire periphery thereof. The lower surface of the recess 12 functions as a second contact surface 14 that contacts the second reference surface 24 of the holder 2 when the lens barrel 1 moves upward. Details thereof will be described later. Further, in the state of FIG. 1, the first contact surface 13 that is the lower surface of the barrel 1 is in contact with the first reference surface 23 that is the upper surface of the holder 2.

  The holder 2 includes a substantially cylindrical holding portion 25 that holds the lens barrel 1 and a base portion 26 provided around the holding portion 25 and downward. The upper surface of the holding portion 25 is a first portion of the holder 2. The first reference surface 23 is in contact with the contact surface 13. Further, a collar portion 22 is formed on the entire upper portion of the holding portion 25, and a lower surface thereof is a second surface that comes into contact with the second contact surface 14 of the holder 2 when the lens barrel 1 moves upward. The reference plane 24 is used.

  Both the first reference surface 23 and the second reference surface 24 face the direction perpendicular to the optical axis direction with respect to the lens 4 held by the lens barrel 1 and face opposite directions. Are formed to face each other. In the state of FIG. 1, the first reference surface 23 and the first contact surface 13 are in contact with each other. When the lens barrel 1 moves in the optical axis direction of the lens 4, the second reference surface 24 and the second contact surface 13 are in contact. Is switched to a contact state with the contact surface 14.

  The lens barrel 1 and the holder 2 are connected via a bimetal 7 so that the lens barrel 1 can move relative to the holder 2 by reversal of the bimetal 7. 2 shows a configuration diagram of the bimetal 7, FIG. 2A shows a perspective view of the bimetal 7, and FIG. 2B shows a cross-sectional view of the bimetal 7. As shown in FIG. 2 (b), the bimetal 7 as a whole has a shape obtained by cutting off a spindle-shaped top portion and constitutes a curved surface portion 30. Further, as shown in FIG. 2A, lens barrel side fixing claws 31 inserted into the lens barrel 1 are formed at four locations in the circumferential direction on the inner peripheral side of the curved surface portion 30, and on the outer peripheral side of the curved surface portion 30. The holder side fixing claws 32 inserted into the holder 2 are formed at four locations in the circumferential direction.

  A pair of electrodes 34 is provided on the upper surface of the curved surface portion 30, and a ring-shaped heating element 33 is provided over substantially the entire circumference of the curved surface portion. When the heating element 33 is energized through the electrode 34, the heating element 33 generates heat and raises the temperature of the bimetal 7. When the bimetal 7 reaches a predetermined temperature, the curved surface portion 30 performs a reverse operation. Further, when the energization to the heating element 33 is stopped from this state, the temperature of the bimetal 7 is lowered, and when the bimetal 7 becomes a predetermined temperature or less, the curved surface portion 30 performs a normal rotation operation.

  Since the curved surface portion 30 has a shape obtained by cutting off the top portion of the spindle shape, the bimetal 7 hardly deforms until reaching the predetermined temperature even when the temperature is increased by the heating element 33, and the moment when the temperature reaches the predetermined temperature. Can be reversed. The same applies to the forward rotation operation, and the forward rotation operation occurs at the moment when the temperature drops to a predetermined temperature.

  FIG. 3 is a cross-sectional view illustrating a state after the bimetal 7 is reversed. As shown in this figure, when the bimetal 7 reaches a predetermined temperature and reverses, the lens barrel 1 moves upward with respect to the holder 2, and the second contact surface 14 of the lens barrel 1 becomes the second of the holder 2. Stops when it comes into contact with the reference surface 24. Thereby, the contact state between the first contact surface 13 and the first reference surface 23 shown in FIG. 1 is switched to the contact state between the second contact surface 14 and the second reference surface 24. The lens 4 held in the lens barrel 1 is positioned. In the contact state between the second contact surface 14 and the second reference surface 24, the bimetal 7 is in a state in which the lens barrel 1 is urged upward, thereby stably stabilizing the position of the lens barrel. Can be held. When the bimetal 7 is lowered to a predetermined temperature or lower from this state, the bimetal 7 rotates forward and switches back to the contact state between the first contact surface 13 and the first reference surface 23.

  In this way, the lens barrel 1 moves in the optical axis direction of the lens 4 with respect to the holder 2 in accordance with the reversal operation and the normal rotation operation of the bimetal 7, thereby switching the contact state between each contact surface and the reference surface. The normal shooting mode and the close-up shooting mode can be switched by switching the distance between the lens 4 and the image sensor 5.

  Next, a second embodiment of the present invention will be described. FIG. 4 shows a cross-sectional view of the camera module in the present embodiment. As shown in this figure, the camera module according to the present embodiment is a camera module according to the first embodiment in which the lens barrel 1 is doubled and the lens barrels are connected via a bimetal 7.

  The lens barrel 1 is composed of a first lens barrel 1a held by a holder 2 and a second lens barrel 1b held by the first lens barrel 1a and having a lens 4 inside. The first lens barrel 1 a is formed with a first flange 22 a on the outer peripheral surface, and the upper surface thereof is a first contact surface 13. The lower surface of the first lens barrel 1a is a second contact surface 14. A first recess 12a is formed on the inner peripheral surface of the holder 2, and the upper surface thereof is a first reference surface 23 that contacts the first contact surface 13 of the first lens barrel 1a. Further, a second reference surface 24 is set on the upper surface of the substrate 3 so that the second contact surface 14 of the first lens barrel 1a contacts.

  Further, a second recess 12 b is formed on the inner peripheral surface of the first lens barrel 1 a, the lower surface thereof is a third reference surface 27, and the upper surface is a fourth reference surface 28. Similar to the first reference surface 23 and the second reference surface 24, the third reference surface 27 and the fourth reference surface 28 are perpendicular to the optical axis direction of the lens 4 and opposite to each other. It is arranged to face.

  The second lens barrel 1b has a second flange portion 22b formed on the outer peripheral surface, the lower surface of which is a third contact surface 17 that contacts the third reference surface 27, and the upper surface is a fourth surface. The fourth contact surface 18 is in contact with the reference surface 28.

  The first lens barrel 1a and the holder 2 are connected via a first bimetal 7a, and the first lens barrel 1a and the second lens barrel 1b are connected via a second bimetal 7b. Yes. The configuration of the first bimetal 7a and the second bimetal 7b is the same as that of the bimetal 7 in the first embodiment. FIG. 4 shows the state before the inversion operation of both the first bimetal 7a and the second bimetal 7b, and the inversion operations of the first bimetal 7a and the second bimetal 7b are opposite to each other. Has been placed.

  FIG. 5 is a cross-sectional view showing a state after the first bimetal 7a is reversed. As shown in this figure, when the first bimetal 7a is heated by the heating element 33 and reversed, the first lens barrel 1a moves downward, and the first reference surface 23 and the first contact surface are moved. 13 is released and the second contact surface 14 contacts the second reference surface 24 and stops. That is, when the first bimetal 7a is reversed, the contact state between the first reference surface 23 and the first contact surface 13 and the second reference surface 24 and the second contact surface 14 are reversed. The contact state is switched, and the position of the lens 4 moves downward by a vertical distance (A) between the first reference surface 23 and the second reference surface 24 as compared to the state of FIG.

  FIG. 6 is a cross-sectional view showing a state after the second bimetal 7b is reversed. As shown in this figure, when the second bimetal 7b is heated by the heating element 33 and reversed, the second lens barrel 1b moves upward, and the third reference surface 27 and the third contact surface are moved. The state of contact with 17 is released, and the fourth contact surface 18 contacts the fourth reference surface 28 and stops. That is, when the second bimetal 7b is reversed, the contact state between the third reference surface 27 and the third contact surface 17 and the relationship between the fourth reference surface 28 and the fourth contact surface 18 are reduced. The contact state is switched, and the position of the lens 4 is moved by the vertical distance (B) between the third reference surface 27 and the fourth reference surface 28 as compared with the state of FIG.

  FIG. 7 is a cross-sectional view showing a state after both the first bimetal 7a and the second bimetal 7b are reversed. As shown in this figure, when both the first bimetal 7a and the second bimetal 7b are heated by the heating element 33 and reversed, the first lens barrel 1a moves downward, and the second mirror Since the cylinder 1b moves upward, the position of the lens 4 moves by the difference between the movement distance A of the first lens barrel 1a and the movement distance B of the second lens barrel 1b. In the present embodiment, the distance B is made larger than the distance A. Therefore, the lens 4 moves upward, and the movement distance C is distance B−distance A.

FIG. 8 shows the relationship between the subject distance (X) and the distance between the lens and the image sensor (Y). These are expressed as follows using f which is a lens focal length.
1 / X + 1 / Y = 1 / f
As described above, four positions of the lens 4 can be set according to the operation or non-operation of the first bimetal 7a and the second bimetal 7b. The subject distance at each position of the lens 4 is as shown in FIG.

  That is, when both the first bimetal 7a and the second bimetal 7b are inactive, the distance between the lens and the image sensor is Y2, and the subject distance to be focused is X3. On the other hand, when only the first bimetal 7a is reversed, the distance between the lens and the image sensor is Y1 (= Y2-A), and the subject distance to be focused is X4. When only the second bimetal 7b is reversed, the distance between the lens and the image sensor is Y4 (= Y2 + B), and the subject distance to be focused is X1. Further, when both the first bimetal 7a and the second bimetal 7b are reversed, the distance between the lens and the image sensor is Y3 (= Y2 + B−A), and the subject distance to be focused is X2. .

  As described above, in addition to the configuration of the first embodiment, the lens barrel 1 is doubled and connected via the bimetal 7 so that four distances between the lens 4 and the image sensor 5 can be set. Since it is possible, mode setting from close to normal can be made more finely.

  As mentioned above, although embodiment of this invention was described, application of this invention is not restricted to these embodiment, It can apply variously within the range of the technical idea.

It is sectional drawing of the camera module in 1st Embodiment. It is a perspective view of a bimetal. It is sectional drawing of the camera module which showed the state after bimetal operation | movement. It is sectional drawing of the camera module in 2nd Embodiment. It is sectional drawing of the camera module which showed the state after the 1st bimetal operation | movement. It is sectional drawing of the camera module which showed the state after the 2nd bimetal operation | movement. It is sectional drawing of the camera module which showed the state after the 1st and 2nd bimetal operation | movement. It is the figure which showed the relationship between a to-be-photographed object distance and the distance between lenses and image sensors.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens barrel 2 Holder 3 Board | substrate 4 Lens 5 Image pick-up element 7 Bimetal 12 Concave part 13 1st contact surface 14 2nd contact surface 22 Gutter part 23 1st reference surface 24 2nd reference surface 30 Curved surface part 31 Mirror Cylinder side fixed claw 32 Holder side fixed claw 33 Heating element 34 Electrode

Claims (6)

In a camera module comprising a lens barrel that holds a lens, and a holder that holds the lens barrel so as to be movable in the optical axis direction of the lens,
The holder includes a first reference surface and a second reference surface that are perpendicular to the moving direction of the lens barrel and are opposite to each other, and the lens barrel is moved in the optical axis direction of the lens. A first contact surface that contacts the reference surface and a second contact surface that contacts the second reference surface,
The holder and the lens barrel are connected via a bimetal, and according to the operation of the bimetal, the contact state between the first contact surface and the first reference surface, and the second contact surface A camera module, wherein the lens barrel is positioned with respect to a holder by switching a contact state with a second reference surface.   The camera module according to claim 1, wherein the bimetal is provided so as to be suspended between an inner peripheral surface of the holder and an outer peripheral surface of the lens barrel.   The bimetal is provided over substantially the entire circumference between the inner peripheral surface of the holder and the outer peripheral surface of the lens barrel, and a heating element is provided in a ring shape on the surface. 2. The camera module according to 2.   The said holder has a collar part in the outer peripheral surface holding the said lens-barrel, At least one of the upper surface or lower surface of this collar part is any reference surface, The any one of Claims 1-3 characterized by the above-mentioned. The camera module according to item.   5. The lens barrel has a recess extending over the entire circumference on an inner peripheral surface, and at least one of an upper surface or a lower surface of the recess is an abutting surface that abuts on a reference surface of the flange portion. Camera module. The lens barrel includes a first lens barrel held by the holder, and a second lens barrel that is held in the first lens barrel so as to be movable in the optical axis direction of the lens and holds the lens therein. Become
The first lens barrel includes a first reference surface, a second contact surface, and a third reference surface and a fourth reference surface that are perpendicular to the moving direction of the lens barrel and are opposite to each other. And the second lens barrel has a third contact surface that contacts the third reference surface and a fourth contact surface that contacts the fourth reference surface as the lens moves in the optical axis direction. And
The first lens barrel and the second lens barrel are connected via a second bimetal, and the third abutting surface and the third reference surface are operated according to the operation of the second bimetal. The second lens barrel is positioned with respect to the first lens barrel by switching between a contact state and a contact state between the fourth contact surface and the fourth reference surface. The camera module according to any one of claims 1 to 5.

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