JP4765442B2 - Lens barrel unit and imaging device - Google Patents

Description

  The present invention relates to a lens barrel unit and an imaging apparatus in which a plurality of members including a translucent member are fixed to a lens barrel.

  In the lens barrel unit, a plurality of optical members such as lenses are positioned and fixed inside the lens barrel so as to keep the position and angle of each other and the imaging surface such as an image sensor or a film surface appropriately. The Such positioning accuracy may not be a problem with general fitting, but especially in an electronic imaging apparatus or the like, position adjustment (so-called alignment) must be performed as the imaging element becomes smaller and the number of pixels increases. The number of cases that must not be increased.

  In order to adhere the optical member and the image sensor to the lens barrel while finely adjusting the optical member and the image sensor, it is necessary to prevent the adhesive from being cured before the fine adjustment of the optical member and the image sensor is completed. When an adhesive having a long curing time is used, it is necessary to hold the optical member or the image pickup device for a long time while being positioned with respect to the lens barrel.

Therefore, as described in Patent Document 1, the adhesive is not cured until fine adjustment of the optical member and the imaging element is completed by using a photocurable resin that is cured by light such as ultraviolet rays as an adhesive. In addition, when the positioning of the optical member and the image sensor is finished, the adhesive can be instantaneously cured to fix the optical member and the image sensor to the lens barrel.
JP 2005-45417 A

  The lens barrel is formed of a light-shielding material in order to prevent light from entering the lens barrel unit from other than a predetermined optical axis direction. For this reason, in order to fix the light-shielding member to the lens barrel, as described in Patent Document 1, the light-curing resin is not covered with the surface between the lens barrel and the member to be fixed. It is necessary to fill and harden. In this case, a space for placing the photocurable resin in the lens barrel is necessary, and there is a problem that the lens barrel unit cannot be reduced in size.

  In addition, as shown in FIG. 6, when a transparent lens 33 is fixed to the lens seat 32 of the lens barrel 31, the photo-curing property applied to the joint surface in the optical axis direction between the lens seat 32 and the first lens 33. The resin p <b> 1 can be cured by the ultraviolet ray R that has been irradiated with the ultraviolet ray R from the optical axis x direction and passed through the first lens 33. However, if an attempt is made to fix the light-shielding ball frame 35 that holds the second lens 34 to the first lens 33 thus fixed, the photocuring property applied to the first lens 33, the ball frame 35, and the bonding surface. The resin p2 can no longer be irradiated with ultraviolet rays. For this reason, in order to fix the lens frame 35 with high accuracy, the diameter of the lens barrel 31 must be increased so that the photocurable resin p can be built up. It was.

  In view of the above problems, it is an object of the present invention to provide a compact lens barrel unit and an imaging apparatus in which a light-transmitting member and a light-shielding member are overlapped and fixed to a lens barrel.

In order to solve the above-described problems, a lens barrel unit according to the present invention includes a light-shielding lens barrel having a lens seat protruding inward, and a first adhesive bonded to the lens seat with a photocurable resin in the optical axis direction. A first translucent member provided with an adhesive portion and a second translucent member are held , overlapped with the first translucent member in the optical axis direction, and a photocurable resin is disposed on the first translucent member. And a light-shielding holding frame provided with a second adhesive portion bonded in the optical axis direction, and at least one of the first adhesive portion and the second adhesive portion is a light projection hole provided in the lens barrel It is assumed that the first translucent member, which can be desired from the outside via the, is provided at a portion adjacent to an end surface in a direction perpendicular to the optical axis.

  According to this configuration, the light curable resin can be cured by the light transmitted through the first light transmissive member by irradiating light from the end face of the first light transmissive member. The light-shielding member can be bonded to the lens barrel or to the first light-transmitting member bonded to the lens barrel with a photocurable resin. For this reason, the first light-transmissive member and the light-shielding member can be aligned with respect to the lens barrel and fixed accurately without increasing the size of the lens barrel unit.

  In addition, the lens barrel unit of the present invention may include a light-shielding sealing member that seals the light projection hole. This prevents extra light from entering the optical path.

  In the lens barrel unit of the present invention, the light-shielding member may have a second light-transmissive member fixed thereto. As a result, the second translucent member can be accurately positioned and fixed.

  An imaging device having the lens barrel unit can be provided at a low cost while being small and highly accurate.

Further, according to the present invention, the first light transmissive member is fixed in the optical axis direction to the lens seat portion protruding inside the light-shielding lens barrel, and the second light transmissive member is attached to the first light transmissive member. A method of assembling a lens barrel unit in which a light-shielding holding frame for holding the lens is overlapped and fixed in the optical axis direction. A light projecting hole that can be desired from the outside is provided, and a photocurable resin is provided between the lens seat portion and the first light transmissive member, or between the first light transmissive member and the holding frame. Applying, aligning the holding frame so that the axis of the first translucent member or the axis of the second translucent member coincides with the optical axis, and the first translucent through the light projection hole It is set as the method of irradiating the end surface of a member with a light ray, and hardening | curing the said photocurable resin with the said light ray which permeate | transmitted the said 1st translucent member. It may be bonded to the holding frame to the first translucent member adhered to the lens seat, the first light-transmissive member in advance bonded to the holding frame may be bonded to the lens seat.

  According to this method, since the first light-transmissive member and the light-shielding member are aligned with respect to the lens barrel, the photocurable resin can be cured by irradiating the light beam from the light projection hole. In addition, the first light-transmissive member and the light-shielding member can be fixed with high accuracy.

  According to the present invention, since the lens barrel is provided with the light projection hole through which at least a part of the end surface of the first transparent member can be desired from the outside, light is applied from the end surface of the first transparent member to the photocurable resin on the adhesive surface. Can be cured by irradiation. For this reason, even if it cannot irradiate light to an optical axis direction with respect to a contact surface, a lens barrel and a 1st translucent member, or a 1st translucent member and a light-shielding member are fixed accurately. be able to.

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 shows a digital camera (imaging device) 1 according to a first embodiment of the present invention. The digital camera 1 is provided with a flash 3, a finder 4, and a lens opening 5 on the front surface of a main body 2, and a lens barrel unit 6 is provided inside the main body 2 so that a subject can be seen from the lens opening 5. .

  FIG. 2 is a longitudinal section of the lens barrel unit 6 portion of the digital camera 1. The lens barrel unit 6 constitutes a bending optical system that bends the optical axis x of the light incident from the subject by 90 °, and the first lens barrel 7 on the subject side (upper side) in the optical axis x direction and the second intermediate lens. The lens barrel 8 and the third lens barrel 9 on the image plane side (lower side) are integrally fixed.

  In the first lens barrel 7, a first lens group 10 including an optical member that bends light incident from a subject by 90 °, and a second lens group 11 that is a variable power lens movable up and down along the optical axis x. And are provided. A shutter unit 12 is fixed in a gap provided at a joint portion between the first lens barrel 7 and the second lens barrel 8.

  Inside the third lens barrel 9, a third lens group 13 into which light that has passed through the shutter unit 12 enters, a fourth lens group 14 that can move in the direction of the optical axis x inside the third lens barrel 9, Furthermore, on the lower side, the fifth lens group 15, a low-pass filter 16 that blocks high-frequency components of light that has passed through the fifth lens group 15, and an imaging element 17 that has an imaging surface on which light that has passed through the low-pass filter 16 forms an image. And are provided. The imaging device 17 is a CCD that converts an image formed on the imaging surface into an electrical signal. The imaging device 17 removes heat from the flexible substrate 18 that is a wiring board to be wired to the imaging device 17 and the imaging device 17, and in the surrounding air. The heat radiating member 19 to be diffused is bonded and fixed to the lower end of the third lens barrel 9 by a pressing member 20.

  FIG. 3 shows the third lens barrel 9 and the fifth lens group 15 in detail. The third lens barrel 9 has a lens seat portion 21 protruding inward, and the fifth lens group 15 is fixed to the lens seat portion 21. The fifth lens group 15 includes a translucent positive lens (first translucent member) 22 bonded to the lens seat portion 21 with a photocurable resin p1 that is cured by ultraviolet rays, and a photocurable resin p2 attached to the positive lens 22. And a negative lens (second translucent member) 24 fixed to the ball frame 23. In addition, the third lens barrel 9 is provided with three light projecting holes 25 (one is not shown) provided so that the end surface perpendicular to the optical axis x direction of the positive lens 22 is exposed. A light-shielding adhesive tape (sealing member) 26 for sealing the light hole 25 is attached.

  Further, FIG. 4 shows a first step when the fifth lens group 15 is fixed. First, the photocurable resin p <b> 1 is applied to a portion of the third lens barrel 9 that contacts the positive lens 22 of the lens seat 21 in the optical axis x direction, and the positive lens 22 is placed on the lens seat 21. The positive lens 22 is held in an aligned state so that the axis of the positive lens 22 coincides with the optical axis x, and as shown in the figure, the ultraviolet ray R is irradiated in parallel with the optical axis x and transmitted through the positive lens 22. The photocurable resin p1 is cured by the ultraviolet ray R (first adhesive portion 27).

  Subsequently, as shown in FIG. 5, a ball frame 23 to which a negative lens 24 is bonded in advance is placed on the positive lens 22. At this time, the photocurable resin p2 is applied to the portion adjacent to the end surface that can be desired from the outside through the light projection hole 25 on the surface of the positive lens 22 that contacts the lens frame 23 in the optical axis x direction. Then, the lens frame 23 is held in a state where the axis of the negative lens 24 is aligned with the optical axis x, and the ultraviolet ray R is irradiated from the light projection hole 25. In this way, the photocurable resin p2 is cured by the ultraviolet ray R transmitted through the positive lens 22, and the ball frame 23 is bonded to the positive lens 22 (second bonding portion 28). Finally, as shown in FIG. 3, an adhesive tape 26 is attached to the outside of the third lens barrel 9 so as to seal the projection hole 25.

  As described above, the lens barrel unit 6 to which the fifth lens group 15 is fixed has high optical accuracy because the positive lens 22 and the negative lens 23 are aligned and fixed. Moreover, since the ultraviolet ray R for hardening the photocurable resin p2 can be irradiated from the lateral direction of the third lens barrel 9 by providing the light projection hole 25, the third lens barrel 9 has an extra space in the radial direction. There is no need to provide it. Thereby, the lens barrel unit 6 has a small projection area in the optical axis x direction and is small.

  In the present embodiment, after fixing the positive lens 22 to the lens seat portion 21, the lens frame 23 having the negative lens 24 fixed to the positive lens 22 is fixed, but the lens frame 23 having the negative lens 24 fixed is positive. After the lens 22 is axially aligned and fixed, a photocurable resin p1 is applied to a portion (first adhesive portion 27) adjacent to the light projection hole 25 of the lens seat portion 21, and the positive lens 22 is attached to the lens seat portion 21. The positive lens 22 may be fixed to the lens seat 21 by curing the photocurable resin p <b> 1 by irradiating with ultraviolet rays R from the projection hole 25.

1 is a front view of a digital camera according to a first embodiment of the present invention. Sectional drawing in the optical axis of the digital camera of FIG. Sectional drawing of the 3rd lens barrel and 5th lens group of the digital camera of FIG. Sectional drawing which shows the 1st process of fixing the 5th lens group to the 3rd lens barrel of FIG. Sectional drawing which shows the 2nd process of fixing the 5th lens group to the 3rd lens barrel of FIG. Sectional drawing of the conventional lens barrel unit.

Explanation of symbols

1 Digital camera (imaging device)
6 Lens Unit 9 Third Lens Unit 15 Fifth Lens Group 21 Lens Seat 22 Positive Lens (First Translucent Member)
23 Ball frame (light-shielding member)
24 Negative lens (second translucent member)
25 Projection hole 26 Adhesive tape (sealing material)
27 1st adhesion part 28 2nd adhesion part p1 photocurable resin p2 photocurable resin

Claims (7)

A light-shielding lens barrel having a lens seat protruding inward;
A first translucent member provided with a first adhesive portion adhered to the lens seat portion in the optical axis direction with a photocurable resin;
A second adhesive member is provided that holds the second light transmissive member, is overlapped with the first light transmissive member in the optical axis direction, and is bonded to the first light transmissive member with a photocurable resin in the optical axis direction. A light-shielding holding frame ,
At least one of the first adhesive part and the second adhesive part is a direction perpendicular to the optical axis of the first translucent member that can be desired from the outside through a light projection hole provided in the lens barrel. A lens barrel unit provided in a portion adjacent to the end face of the lens.   The lens barrel unit according to claim 1, further comprising a light-shielding sealing member that seals the projection hole.   The lens barrel unit according to claim 1, wherein a second light transmissive member is fixed to the light shielding member.   An imaging apparatus comprising the lens barrel unit according to claim 1. A light-shielding holding frame that fixes a first light-transmissive member to the lens seat protruding inside the light-shielding lens barrel in the optical axis direction, and holds the second light-transmissive member on the first light-transmissive member. Is a method of assembling a lens barrel unit that is fixed by overlapping in the optical axis direction,
The lens barrel is provided with a light projecting hole through which a part of an end face in a direction perpendicular to the optical axis of the first light transmissive member can be desired from the outside.
Applying a photocurable resin between the lens seat and the first light transmissive member, or between the first light transmissive member and the holding frame ,
The holding frame is aligned so that the axis of the first translucent member or the axis of the second translucent member coincides with the optical axis,
A lens barrel unit that irradiates a light beam to the end surface of the first light transmissive member from the light projection hole and cures the photocurable resin by the light beam transmitted through the first light transmissive member. Assembly method. After the photocurable resin is applied to the lens seat, the first light transmissive member is disposed so as to overlap in the optical axis direction, and the light beam is irradiated through the first light transmissive member. Curing the photocurable resin between the lens seat and the first translucent member;
A photocurable resin is applied to the surface opposite to the optical axis direction of the first light transmissive member, and then the holding frame is disposed so as to overlap in the optical axis direction, and the axis of the second light transmissive member is arranged. In a state where the holding frame is moved and aligned so as to coincide with the optical axis, a light beam is irradiated from the light projecting hole to the end surface of the first light transmissive member, and the first light transmissive member is moved. 6. The method of assembling a lens barrel unit according to claim 5, wherein the photocurable resin between the first light transmissive member and the holding frame is cured by the transmitted light beam. The first translucent member and the holding frame are disposed so as to overlap in the optical axis direction via a photocurable resin, and the axis of the second translucent member is the axis of the first translucent member. In the state where the holding frame is moved and aligned so as to coincide with the first transmissive member, the light curable resin between the first translucent member and the holding frame is irradiated with light, and the first translucent resin is irradiated. Curing the photocurable resin between the adhesive member and the holding frame ,
After applying a photocurable resin to the lens seat, the first light transmissive member is placed on the lens seat, and the axis of the first light transmissive member is aligned with the optical axis. In the state where the first translucent member is moved and aligned, the end surface of the first translucent member is irradiated with light from the light projection hole, and the first translucent member is transmitted. 6. The method of assembling a lens barrel unit according to claim 5, wherein the photocurable resin between the lens seat portion and the first translucent member is cured by a light beam.

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