JP2005173414A - Lens barrel and camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel which allows play in a main body thereof to be eliminated while being made small-sized and low-cost. <P>SOLUTION: A lens barrel has; a first barrel member (1); a second barrel member (2) which is brought into contact with the first barrel member in the direction of an optical axis and can be rotated around the optical axis relative to the first barrel member; a first lens holding member (6) which is brought into contact with the first barrel in the direction of the optical axis; and an energizing member (4) having a fixed part fixed to the first barrel member, first energizing parts (402a to 402e) for energizing the second barrel member in such a direction that the second barrel member is brought into contact with the first barrel member, and second energizing parts (403a to 403c) for energizing the first lens holding member in such a direction that the lens holding member is brought into contact with the first barrel member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lens barrel suitable for a camera having a zoom function.

  Conventionally, as a structure for fixing a lens to a lens barrel, there is a structure in which a plastic lens is pressed and fixed to a lens barrel with a push ring having spring elasticity (for example, see Patent Document 1).

  Further, it eliminates backlash in the optical axis direction between the rectilinear cylinder that advances and retreats in the optical axis direction and the rotary cylinder that engages with the rectilinear cylinder and is rotatable with respect to the rectilinear cylinder and moves integrally in the optical axis direction. For this purpose, an elastic member such as a coil spring is disposed between the flange portion of the fixed cylinder and the end surface of the rotating cylinder, and the rotating cylinder is urged in the optical axis direction with respect to the fixed cylinder (for example, Patent Document 2). reference).

Further, there is a type in which a leaf spring-shaped elastic member is fixed to the tip of the cam barrel and is urged in the optical axis direction with respect to the barrel main body (see, for example, Patent Document 3).
JP-A-5-188253 (paragraph number 0018, FIG. 1) JP-A-9-329735 (paragraph number 0015, FIG. 1) JP 2000-180689 A (paragraph number 0010, FIG. 2)

  However, the lens fixing structure proposed in Patent Document 1 requires a dedicated elastic member (plate spring) for fixing the lens, which increases the number of parts and increases the cost. Will become larger.

  On the other hand, in the structures proposed in Patent Document 2 and Patent Document 3, since the width of the elastic member (the width in the radial direction) is less than the wall thickness of the cylinder, it is difficult to give a large pressing force to the elastic member. Further, since the spring constant becomes high, the pressing force of the elastic member varies due to variations in the dimensions of the lens barrels during production, and it becomes difficult to remove the play stably.

  Furthermore, in order to arrange the elastic member in the narrow width, it is necessary to bend the elastic member in the optical axis direction or to provide a protrusion, but in this case, the shape of the elastic member becomes complicated. This may increase the cost or increase the thickness in the optical axis direction and increase the size of the lens barrel.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a lens barrel capable of fixing a lens while reducing costs and downsizing without using new parts. . It is another object of the present invention to provide a lens barrel that can reduce the overall length (length in the optical axis direction) of the lens barrel.

  The lens barrel according to the first invention of the present application is in contact with the first lens barrel member and the first lens barrel member in the optical axis direction and around the optical axis with respect to the first lens barrel member. A second lens barrel member capable of rotating at the first lens holding member, a first lens holding member that comes into contact with the first lens barrel member in the optical axis direction, and a fixed portion fixed to the first lens barrel member The first urging portion for urging the second lens barrel member in the abutting direction with respect to the first lens barrel member and the first lens holding member in the abutting direction with respect to the first lens barrel member. And an urging member having a second urging portion for energizing.

  The lens barrel according to the second invention of the present application is in contact with the first lens barrel member and the first lens barrel member in the optical axis direction and around the optical axis with respect to the first lens barrel member. A second lens barrel member capable of rotating at the first position, a fixing portion fixed to the first lens barrel member, and a biasing force for biasing the second lens barrel member in the direction of contact with the first lens barrel member A biasing member having a biasing portion, and the first barrel member has a fixing surface with which the fixing portion of the biasing member abuts in the optical axis direction, and the biasing portion in the second barrel member The part which abuts protrudes to the urging | biasing part side rather than the fixed surface, It is characterized by the above-mentioned.

  The lens barrel of the present invention described above can be provided in a camera having an image sensor that photoelectrically converts light from the lens barrel.

  According to the first invention of the present application, the second lens barrel member is urged in the abutting direction with respect to the first lens barrel member by using one urging member, and the first lens holding member is Compared to the case where two urging members for urging each of the second lens barrel member and the first lens holding member are provided to urge the lens barrel member 1 in the contact direction, the number of parts is reduced. The lens barrel can be reduced in size and cost. If this lens barrel is provided in the camera, the camera can be reduced in size and cost.

  According to the second aspect of the present invention, the biasing member can be configured with a simple configuration by causing the portion of the second barrel member that the biasing portion abuts to protrude from the fixed surface toward the biasing portion. Can be given an urging force, and the backlash between the second lens barrel member and the first lens barrel member can be eliminated by this urging force.

  By making the urging member a plate-like spring whose optical axis direction is the thickness direction, the length of the lens barrel in the optical axis direction can be shortened.

  The abutting direction of the second lens barrel member to the first lens barrel member and the abutting direction of the first lens holding member to the first lens barrel member are the same direction, and the first and second If the urging portions generate urging forces in the same direction, the configuration of the lens barrel can be simplified.

  The urging member has a ring shape, and the first urging portion is provided on the outer peripheral side portion of the urging member, and the second urging portion is provided on the inner peripheral side portion of the urging member, whereby the second barrel member The urging member can be provided with the above-described two urging forces in correspondence with the configuration arranged on the outer side of the first barrel member.

  If the position of the first lens holding member can be adjusted in the direction perpendicular to the optical axis with respect to the first lens barrel member, the central axis of the lens holding member arranged in the lens barrel can be aligned. It is possible to prevent the deviation of the photographing optical axis.

  The first lens barrel member is provided with a fixing surface on which the fixing portion of the urging member abuts in the optical axis direction, and a portion of the second lens barrel member on which the first urging portion abuts is formed from the fixing surface. Further, by projecting toward the second urging portion, it is possible to give the urging force to the urging member with a simple configuration.

  As described above, the backlash in the second lens barrel member is eliminated by the biasing force of the biasing member, so that the second lens holding member disposed on the image plane side with respect to the first lens holding member can be The lens barrel member can be driven while maintaining the positional accuracy in the optical axis direction.

  In the configuration in which the first and second lens barrel members are movable in the optical axis direction integrally with the lens barrel main body, the first and second lens barrel members are applied by the biasing force of the biasing member described above. Can be driven without play.

  Examples of the present invention will be described below.

  FIG. 9 is a schematic cross-sectional view of a camera including a lens barrel that is Embodiment 1 of the present invention. In the figure, the camera body 20 is provided with a lens barrel 30 having a plurality of photographing lens groups. An imaging element 40 such as a CCD or CMOS image sensor is disposed in the camera body 20, and an optical image formed by a plurality of photographing lens groups in the lens barrel 30 is formed on the imaging element 40. To do.

  The image sensor 40 converts object light into an electrical signal by photoelectric conversion, accumulates this signal, and outputs the accumulated signal. The signal output from the image sensor 40 is subjected to predetermined signal processing by a signal processing circuit 50 provided in the camera body 20, and then output to the display unit 60 and displayed as a captured image on the display unit 60. The The output signal (image signal) of the signal processing circuit 50 is recorded on the recording medium 70.

  FIG. 8 is a cross-sectional view of the lens barrel in the present embodiment.

  A motor 11 serving as a driving source for the lens barrel is fixed to a fixed cylinder 10 fixed to the camera body 20, and a gear 12 press-fitted into the rotation shaft of the motor 11 is engaged with a gear 13 extending in the optical axis direction. ing.

  A helicoid is formed on the outer peripheral surface of the third rotating cylinder 14, and this helicoid is engaged with a helicoid formed on the inner peripheral surface of the fixed cylinder 10. The third rotating cylinder 14 meshes with the gear 13 on the outer periphery. In this configuration, the third rotating cylinder 14 rotates around the optical axis by receiving a driving force from the motor 11 via the gear 13. Here, since the third rotating cylinder 14 is engaged with the fixed cylinder 10 via the helicoid, the third rotating cylinder 14 moves in the optical axis direction while rotating around the optical axis.

  The third rectilinear cylinder 15 is engaged with the third rotating cylinder 14 in a state slidable around the optical axis and positioned in the optical axis direction. Thus, the third rectilinear cylinder 15 does not rotate even when the third rotating cylinder 14 rotates, and can move only in the optical axis direction together with the third rotating cylinder 14.

  The second rotating cylinder 16 is movable in the optical axis direction with respect to the third rotating cylinder while rotating around the optical axis by the engaging action of the third rotating cylinder 14 and the third rectilinear cylinder 15. The second rectilinear cylinder 17 is engaged with the third rotating cylinder 14 and is slidable with respect to the rotation of the second rotating cylinder 16 (that is, does not rotate around the optical axis). Together with the rotating cylinder 16, it can move integrally in the optical axis direction.

  The first rotating cylinder (second lens barrel member) 2 rotates around the optical axis by the engaging action of the second rotating cylinder 16 and the second rectilinear cylinder 17, and the optical axis with respect to the second rotating cylinder 16. It can move in the direction. As will be described later, the first rectilinear cylinder 1 (first lens barrel member) is engaged with the first rotating cylinder 2 and is slidable with respect to the rotation of the first rotating cylinder 2 (that is, It does not rotate around the optical axis) but can move integrally with the first rotating cylinder 2 in the optical axis direction.

  The third lens frame 18 that holds the photographing lens group is fixed to the rear portion (the end portion on the image plane side) of the first rectilinear barrel 1.

  In the above structure, when the motor 11 is rotated in one direction, this driving force is transmitted to the third rotating cylinder 14 via the gear 13, and the third rotating cylinder 14, the second rotating cylinder 16 and the first rotating cylinder 2 are transmitted. Each of these is extended in the optical axis direction. On the other hand, when the motor 11 is rotated in the other direction, this driving force is transmitted to the third rotating cylinder 14 via the gear 13, and the third rotating cylinder 14, the second rotating cylinder 16 and the first rotating cylinder 2 are optical axes. It will be carried in the direction. As a result, a multistage lens barrel is configured (known configuration).

  FIG. 1 is an exploded perspective view of a unit including a first rotating cylinder 2 and a first rectilinear cylinder 1 in the lens barrel of the present embodiment, and shows a state where some components are cut along a plane including an optical axis. ing.

  In FIG. 1, a plurality of bayonet portions 101 are formed in the circumferential direction at the rear end portion in the optical axis direction of the first rectilinear cylinder 1. These bayonet portions 101 are formed on the inner peripheral surface of the fixed cylinder 2 and are engaged with a groove portion 201 extending in the circumferential direction.

  In this configuration, when the first rotating cylinder 2 rotates around the optical axis, the first rectilinear cylinder 1 slides with respect to the first rotating cylinder 2 and therefore does not rotate around the optical axis. Since 101 is engaged with the groove 201 in the optical axis direction, it moves in the optical axis direction together with the first rotary cylinder 2.

  A second lens frame (second lens holding member) 3 disposed inside the rectilinear cylinder 1 holds the photographing lens 301 at the center. Further, the second lens frame 3 is provided with cam followers 302 at three positions at equal intervals of 120 degrees on the outer periphery, and these cam followers 302 are formed on the first rectilinear cylinder 1 and light The cam groove 202 formed on the inner peripheral surface of the first rotating cylinder 2 is engaged through the linearly extending groove 102 extending in the axial direction.

  The cam groove 202 is an address zoom type cam that alternately performs zooming and focusing. In the above configuration, when the first rotating cylinder 2 rotates around the optical axis with respect to the first rectilinear cylinder 1, the second lens frame 3 advances and retracts in the optical axis direction due to the engaging action of the cam groove 202 and the cam follower 302. In addition, zooming and focusing of the photographing optical system can be performed.

  In FIG. 2, the first lens frame (first lens holding member) 6 holds a lens group 601. When the first lens frame 6 is incorporated into the first rectilinear cylinder 1, flange portions 602a, 602b, and 602c (the flange portion 602c not shown) formed at three locations in the circumferential direction of the first lens frame 6 are Engage with the receiving recesses 103 a, 103 b, 103 c of the single rectilinear cylinder 1. Thereby, the position of the first lens frame 6 in the optical axis direction is determined.

  FIG. 7 is a front view of the urging member 4 incorporated in the lens barrel (first rectilinear barrel 1). In the figure, the urging member 4 is formed in a ring shape, is composed of a flat plate spring having a small thickness, and has elasticity.

  First urging portions 402 a to 402 e that protrude outward in the radial direction of the urging member 4 are formed at five locations on the outer periphery of the urging member 4. Among these first urging portions 402 a to 402 e, the first urging portion 402 b has a first urging portion 402 b that weakens this elastic force and is located substantially opposite to the first urging member 402 b across the center of the urging member 4. A slit portion 402b1 extending in the circumferential direction of the urging member 4 is formed in order to have an elastic force substantially equal to the elastic force of the urging members 402e and 402d.

  That is, the first urging portions 402a to 402e formed at five locations in the circumferential direction of the urging member 4 have an elastic force in a region substantially opposed across the center of the urging member 4 (corresponding to the optical axis). It is formed so as to be substantially equal. Thereby, as will be described later, the urging force for urging the first rotating cylinder 2 by the first urging portions 402a to 402e can be made substantially equal in the circumferential direction (around the optical axis) of the first rotating cylinder 2. .

  Further, second urging portions 403a, 403b, and 403c are formed at three locations on the inner periphery of the urging member 4. Of these second urging portions 403 a to 403 c, the second urging portions 403 b and 403 c are formed in a convex shape so as to extend in the circumferential direction of the urging member 4. Further, the urging member 4 is formed with fixing hole portions (fixing portions) 401e and 401f into which screws for screwing the urging member 4 to the first rectilinear cylinder 1 are inserted.

  Next, a method for fixing the urging member 4 to the first rectilinear cylinder 1 will be described with reference to FIGS. 1 to 3.

  First, the first lens frame 6 is fitted to the first rectilinear barrel 1 from the front of the lens barrel, and the flange portions 602a to 602c are engaged with the receiving recesses 103a to 103c of the first rectilinear barrel 1 in phase. Combine.

  Here, the length of the flange portions 602a to 602c in the optical axis orthogonal direction (the length in the radial direction of the first lens frame 6) is the length of the receiving recesses 103a to 103c in the optical axis orthogonal direction (the first rectilinear cylinder 1). (Length in the radial direction) is shorter by about 1 mm. The lengths of the flange portions 602a to 602c around the optical axis (the length in the circumferential direction of the first lens frame 6) are the lengths around the optical axis of the receiving recesses 103a to 103c (the circumferential direction of the first rectilinear cylinder 1). The length is less than 1 mm.

  Then, the fixing hole portions 401 e and 401 f of the urging member 4 are engaged with the pins 105 formed on the flat surface portion (end surface) 105 of the first rectilinear cylinder 1. Further, the four screws 5 are screwed to the tap holes 104 a to 104 d formed on the end face of the first rectilinear cylinder 1 through the fixing holes 401 a to 401 d of the urging member 4.

  Thereby, as shown in FIG. 3, the urging member 4 is fixed to the flat surface portion (end surface) 105 of the first rectilinear cylinder 1.

  A flat surface portion 203 extending inward in the radial direction of the first rotating cylinder 2 is formed on the inner periphery on the front end side of the first rotating cylinder 2. Since the flat surface portion 203 is located on the front end side of the lens barrel with respect to the flat surface portion 105 of the first rectilinear barrel 1, as shown in FIGS. 4 and 5 at the boundary between the flat surface portion 203 and the flat surface portion 105. , There is a step.

  For this reason, when the urging member 4 is incorporated in the first rectilinear cylinder 1, the first urging portions 402 a to 402 e provided at five locations on the outer periphery of the urging member 4 are connected to the flat surface portion 203 of the first rotating cylinder 2. The elastic deformation is caused by the contact (see FIGS. 4 and 5), and an urging force to the rear portion (image surface side) of the lens barrel is applied to the flat portion 203.

  Accordingly, the first rotating cylinder 2 is pushed into the image plane side relative to the first rectilinear cylinder 1, and the groove portion 201 formed on the inner peripheral surface of the first rotating cylinder 2 becomes the first rectilinear cylinder. One bayonet portion 101 comes into contact with the front surface of the lens barrel (subject side). Thereby, the play in the optical axis direction between the groove part 201 and the bayonet part 101 can be eliminated.

  Here, even if the first rotary cylinder 2 rotates around the optical axis relative to the first rectilinear cylinder 1, the flat portion 203 of the first rotary cylinder 2 is the first biasing portion of the biasing member 4. It moves while sliding with respect to 402a-402e, and receives the urging force from the urging member 4 continuously. Thereby, the 1st rotary cylinder 2 will be driven in the state without the backlash between the groove part 201 and the bayonet part 101. FIG.

On the other hand, in the state where the urging member 4 and the first lens frame 6 are assembled into the first rectilinear cylinder 1, the second urging portions 403a to 403c of the urging member 4 are, as shown in FIG. The flange portions 602a to 602c are urged toward the rear part (image surface side) of the lens barrel and pressed against the receiving recesses 103a to 103c (see FIGS. 4 and 5).
Here, since the flange parts 602a-602c and the receiving recessed parts 103a-103c are formed in the magnitude | size mentioned above, they are in the state with the clearance gap in the surface orthogonal to an optical axis.

  For this reason, when an external force is applied to the first lens frame 6, the first lens frame 6 (flange portions 602a to 602c) moves in a plane perpendicular to the optical axis while being in contact with the receiving recesses 103a to 103c of the first rectilinear cylinder 1. Will move. When the external force to the first lens frame 6 is lost, the first lens frame 6 (flange portions 602a to 602c) receives the urging force of the urging member 4 (second urging portions 403a to 403c). Then, the frictional force between the flange portions 602a to 602c and the second urging portions 403a to 403c stops at the position when the external force is lost.

  By displacing the first lens frame 6 in a plane perpendicular to the optical axis in this way, the center of the first lens frame 6 is set to the central axis of the first rectilinear cylinder 1 or the lens group 301 of the second lens frame 3. It is possible to adjust the position with respect to the central axis. If an adhesive is applied to the gap between the flange portions 602a to 602c and the receiving recesses 103a to 103c, the first lens frame 6 can be reliably fixed to the first rectilinear cylinder 1 in a state where the position is adjusted. it can.

  In the lens barrel of the present embodiment, in a simple configuration in which the urging member 4 is incorporated from the front end side of the lens barrel, the first urging portions 402a to 402e formed on the outer periphery of the urging member 4 perform the first straight advancement. The play in the optical axis direction of the first rotating cylinder 2 with respect to the cylinder 1 is prevented, and the play in the optical axis direction between the lens group 301 of the second lens frame 3 and the lens group 601 of the first lens frame 6 is suppressed.

  Further, as described above, the first lens frame 6 can be held movably within a plane orthogonal to the optical axis by the second urging portions 403a to 403c formed on the inner periphery of the urging member 4. The position of the first lens frame 6 can be adjusted with respect to the photographing optical axis.

  Further, since the biasing member 4 is formed in a ring shape and has a single plane that is continuous in the circumferential direction, variation in the biasing force with respect to the first rotating cylinder 2 and the first lens frame 6 can be reduced. it can. Moreover, since the urging member 4 is a plate member having a small thickness in the optical axis direction, the length of the lens barrel in the optical axis direction can be shortened (miniaturized).

1 is a cross-sectional view of a part of a lens barrel that is Embodiment 1 of the present invention. FIG. 3 is an external perspective view of a part of the lens barrel. FIG. 3 is an external perspective view showing an assembled state of a part of the lens barrel. Sectional drawing of a part of said lens barrel. 2 is a partially enlarged view of the lens barrel of Embodiment 1. FIG. 1 is a front view of a lens barrel of Example 1. FIG. The front view of a biasing member. 1 is a cross-sectional view of a lens barrel of Embodiment 1. FIG. 1 is a schematic cross-sectional view of a camera in Embodiment 1. FIG.

Explanation of symbols

1: first straight cylinder 101: bayonet portion 102: linear groove portions 103a, 103b, 103c: receiving recess 104: tapped hole portion 105: plane portion 2: first rotating tube 201: groove portion 202: cam groove portion 203: plane portion 3: First lens frame 301: Lens group 302: Cam follower (cam pin)
4: urging members 401a, 401b, 401c: fixing holes 402a, 402b, 402c, 402d, 402e: first urging portions 403a, 403b, 403c: second urging portions 5: screws 6: second lens frame 601 : Lens group 602a, 602b, 602c: Flange part 10: Fixed cylinder 11: Motor 12: Gear 13: Gear 14: Third rotating cylinder 15: Third rectilinear cylinder 16: Second rotating cylinder 17: Second rectilinear cylinder 18: Third lens frame

Claims (12)

A first lens barrel member;
A second lens barrel member that is in contact with the first lens barrel member in the optical axis direction and capable of rotating about the optical axis with respect to the first lens barrel member;
A first lens holding member that contacts the first lens barrel member in the optical axis direction;
A fixing portion fixed to the first lens barrel member, a first biasing portion for biasing the second lens barrel member in a contact direction with the first lens barrel member, and the first lens A lens barrel comprising: a biasing member having a second biasing portion that biases the holding member in a contact direction with respect to the first lens barrel member.   The lens barrel according to claim 1, wherein the biasing member is a plate-shaped spring whose thickness direction is the optical axis direction. The contact direction of the second lens barrel member to the first lens barrel member and the contact direction of the first lens holding member to the first lens barrel member are the same direction.
The lens barrel according to claim 1, wherein the first and second urging portions generate urging forces in the same direction. The second lens barrel member is disposed outside the first lens barrel member,
The biasing member has a ring shape;
The first biasing portion is provided on an outer peripheral side portion of the biasing member, and the second biasing portion is provided on an inner peripheral side portion of the biasing member. The lens barrel according to any one of the above.   5. The lens barrel according to claim 1, wherein the position of the first lens holding member can be adjusted in a direction orthogonal to the optical axis with respect to the first lens barrel member. 6. . The first lens barrel member has a fixing surface with which the fixing portion of the biasing member abuts in the optical axis direction,
The portion of the second barrel member with which the first urging portion abuts protrudes closer to the second urging portion than the fixed surface. The lens barrel according to any one of the above.   2. The apparatus according to claim 1, further comprising a second lens holding member that is disposed closer to the image plane than the first lens holding member and is driven in the optical axis direction by the rotation of the second lens barrel member. 6. The lens barrel according to any one of 6 above.   8. The lens mirror according to claim 1, wherein the first and second lens barrel members are movable in the optical axis direction integrally with the lens barrel main body. Tube. A first lens barrel member;
A second lens barrel member that is in contact with the first lens barrel member in the optical axis direction and capable of rotating about the optical axis with respect to the first lens barrel member;
A fixing portion fixed to the first lens barrel member, and a biasing member having a biasing portion that biases the second lens barrel member in a contact direction with respect to the first lens barrel member. ,
The first lens barrel member has a fixing surface with which the fixing portion of the biasing member abuts in the optical axis direction,
The lens barrel characterized in that a portion of the second lens barrel member that abuts against the urging portion protrudes toward the urging portion with respect to the fixed surface.   The lens barrel according to claim 9, wherein the biasing member is a plate-shaped spring whose thickness direction is the optical axis direction.   11. The lens barrel according to claim 9, wherein the first and second lens barrel members are movable in the optical axis direction integrally with the lens barrel main body. The lens barrel according to any one of claims 1 to 11,
An image pickup device that photoelectrically converts light from the lens barrel.

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