JP2011145505A - Lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel with which deterioration of quality of a captured image can be reduced, even if the surrounding environment such as temperature varies when a plastic lens and glass lens are used in the same lens group. <P>SOLUTION: An L9 lens 242 is adhesively fixed to an L9 lens fixer 500. An L8 lens fixer 502 and an L9 lens fixer 500 are constituted as a unit. The L9 lens fixer 500 includes at least three L9 lens outside diameter receivers 454 abutting against the radial end of an L9 lens 242 to regulate the outside diameter of the L9 lens 242. The L9 lens fixer 500 includes an L9 lens receiver 451 abutting on the optical axial direction end of the L9 lens integrally with the L9 lens outside diameter receiver 454 to regulate the height of the L9 lens 242. An L8 lens 241 and the L9 lens 242 are adhesively fixed by an adhesive 470 having the same linear expansion coefficient after curing. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lens barrel, and more particularly to a lens frame disposed inside a lens barrel.

  2. Description of the Related Art In recent years, an image pickup apparatus has been widely used in which incident light from a lens is picked up by using a solid-state image pickup device such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) and converted into an electric signal and then taken out as an image. It has been. In addition, along with the demand for miniaturization and high performance of portable devices such as interchangeable lens DSC (Digital Still Camera), fixed lens DSC, and movies, the size and weight of the lens barrel, which is the main component of the imaging device, is reduced. There is a further demand for reduction in thickness and thickness. In general, a lens barrel is composed of a plurality of lens groups, each of which has a plurality of functional units such as zoom and focus.

  By the way, in recent years, plastic is frequently used instead of glass as a lens material. Plastic lenses are excellent in processability and are less expensive than glass lenses. However, a plastic lens has a property that mechanical strength is lower than that of a glass lens, and distortion tends to occur when the lens is fixed to a lens barrel. Therefore, various proposals have been made as a method for fixing the plastic lens to the lens barrel.

  For example, Patent Document 1 discloses a technique for firmly bonding a plastic lens and preventing the distortion of the plastic lens. Specifically, the remaining gate portion is provided in the plastic lens. A large-diameter portion having a diameter that does not interfere with the remaining gate portion is formed in the lens barrel, and positioning of the plastic lens is performed by fitting the protruding portion of the cylindrical portion to the outer peripheral surface of the lens. Adhesive is supplied to the large diameter part to fix the plastic lens. The adhesive area is increased due to the area of the remaining gate portion, so that the adhesive force is increased. Since the adhesive layer is thick, the buffering action of the adhesive is large and the plastic lens is not distorted.

JP 7-159663 A

  Even when the plastic lens and the glass lens are used in the same lens group, it is important that the plastic lens is not distorted. Therefore, an adhesive having a relatively low adhesive strength (a relatively low tensile force during curing) is used for fixing the plastic lens. On the other hand, in order to support a glass lens having a mass larger than that of a plastic lens, an adhesive having a higher adhesive strength than an adhesive for supporting the plastic lens is used. That is, the physical properties of the adhesive fixing the plastic lens and the adhesive fixing the glass lens are different. Therefore, when the ambient environment such as temperature fluctuates, the expansion amount of the adhesive fixing the plastic lens and the adhesive fixing the glass lens is different, and the glass lens and the plastic lens are displaced from the optical center. Will occur.

  Conventionally, plastic lenses have been used as part of a lens group having a relatively large margin in optical design. Therefore, there are many cases where the shift of the optical center due to the change of the surrounding environment does not become a big problem. However, in recent years, a plastic lens is being used as a part of a lens group having a relatively small margin in optical design in order to reduce the cost of the lens barrel. In this case, there has been a problem that the deviation of the optical center due to changes in the surrounding environment deteriorates the quality of the captured image.

  The present invention has been made to solve the above-described problem. When a plastic lens and a glass lens are used in the same lens group, even if the ambient environment such as temperature fluctuates, the quality of the captured image is deteriorated. An object of the present invention is to provide a lens barrel capable of reducing the above.

  The lens barrel of the present invention has at least one lens group. The lens group includes a glass lens and a plastic lens. The glass lens is bonded and fixed to the glass lens fixing portion so that the lens center is aligned with the optical axis. The plastic lens is bonded and fixed to the plastic lens fixing portion. The glass lens fixing portion and the plastic lens fixing portion are integrally formed on the lens holding frame by resin molding. The plastic lens fixing portion includes at least three lens outer diameter regulating portions that come into contact with the radial end portion of the plastic lens so as to regulate the outer diameter of the plastic lens. Furthermore, the plastic lens fixing portion includes at least three lens height restricting portions that come into contact with the optical axis direction end portion of the plastic lens so as to restrict the height of the plastic lens. Furthermore, the plastic lens fixing portion includes at least three adhesive reservoir portions. The plastic lens fixing part is formed at a position close to the lens outer diameter restricting part, the lens height restricting part, and the adhesive reservoir. The glass lens and the plastic lens are bonded and fixed with an adhesive having the same linear expansion coefficient after curing.

  According to such a configuration, even if the ambient environment such as temperature fluctuates, the plastic lens and the glass lens are fixed with the adhesive having the same linear expansion coefficient, so that the optical centers of the plastic lens and the glass lens are misaligned. Can be reduced.

  Therefore, when the plastic lens and the glass lens are used in the same lens group, it is possible to provide a lens barrel capable of reducing deterioration of the captured image quality even if the ambient environment such as temperature fluctuates.

  Further, the adhesive reservoir portion may be composed of an adhesive portion having a narrow interval with the radial end portion of the plastic lens and a supply portion having a wide interval between the radial end portion of the plastic lens. According to such a configuration, the adhesive can be easily supplied to the adhesive reservoir using a nozzle or the like. Furthermore, the amount of adhesive at the bonded portion is reduced. Therefore, in addition to facilitating the manufacture of the lens barrel, it is possible to provide a lens barrel that can further reduce the degradation of the captured image quality even when the ambient environment such as temperature fluctuates.

  Further, when the entire circumference of the plastic lens is arbitrarily divided into two equal parts, at least one lens outer diameter restricting portion may be provided on each half circumference. According to such a configuration, the plastic lens can be further stably fixed. Therefore, it is possible to provide a lens barrel that can further reduce the degradation of the captured image quality even when the ambient environment such as temperature fluctuates.

  According to the present invention, when a plastic lens and a glass lens are used in the same lens group, a lens barrel capable of reducing deterioration in captured image quality even if the surrounding environment such as temperature fluctuates. Can provide.

Perspective view showing the appearance of a digital still camera The perspective view which shows the external appearance of the lens-barrel accommodated in the inside of the camera AA line sectional view in FIG. The perspective view which shows the detail of the moving mechanism of the 4th lens group in Embodiment 1. FIG. A perspective view showing details of the fourth lens group A perspective view of the fourth lens group as viewed from the opposite side in the Z-axis direction of FIG. 5A Perspective view of the L8 lens Plan view of the L8 lens Sectional view taken along line 1-1 in FIG. 6B The perspective view of L9 lens in an embodiment Perspective view of the L9 lens The top view seen from the L9 lens attachment surface side of the 4th lens group holding frame The top view seen from the L8 lens attachment surface side of the 4th lens group holding frame The figure which expanded a cross section of the 4th lens group holding frame partially The top view which shows the state which attached the L9 lens to the 4th lens group holding frame The top view which shows the state which attached the L8 lens to the 4th lens group holding frame The figure which expanded partially the sectional view of the state where the same L9 lens and L8 lens were attached to the 4th lens group holding frame AA line sectional view in FIG. 9A The top view seen from the L9 lens attachment surface side of the 4th lens group holding frame in Embodiment 2 The top view seen from the L8 lens attachment surface side of the 4th lens group holding frame

  Hereinafter, a lens barrel 111 according to an embodiment of the present invention will be described with reference to the drawings using a digital still camera as an example.

(Embodiment 1)
[1. Configuration of digital still camera]
As shown in FIG. 1, six surfaces serving as a casing of the digital still camera 100 are defined as follows. That is, the surface facing the subject side when photographing with the digital still camera 100 is a front surface portion 101, and the opposite surface is a back surface portion 102. Also, the vertical direction of the subject and the aspect ratio (the ratio of the long side to the short side) captured by the digital still camera 100 coincide with the vertical direction of the short side such as 3: 2, 4: 3, 16: 9, etc. When the image is taken, the surface facing the upper side in the vertical direction is the upper surface portion 103, and the opposite surface is the bottom surface portion 104. Further, a surface on the left side when viewed from the subject side is a left side surface portion 105, and a surface on the opposite side is a right side surface portion 106. The definitions of these surfaces are also applied to each component member arranged in the digital still camera 100.

  Further, as shown in FIG. 1, a three-dimensional orthogonal coordinate system having a Y axis orthogonal to the front surface portion 101 of the digital still camera 100 is defined. That is, the direction from the back surface portion 102 to the front surface portion 101 is the Y axis positive direction, the direction from the right side surface portion 106 to the left side surface portion 105 is the X axis positive direction, and is orthogonal to the X axis and Y axis. The direction toward the portion 103 is the positive Z-axis direction. Hereinafter, in each figure, it demonstrates on the basis of this XYZ coordinate system.

  A front lens 101 of the digital still camera 100 is provided with a first lens 211 that is an objective lens for a subject. The upper surface portion 103 is provided with a shooting mode switching button 107, a release button 108, a power switch 109, a zoom adjustment lever 110, and the like so that a photographer can perform shooting operations and the like. The release button 108 is a button for the photographer to input the exposure timing. The shooting mode switching button 107 is a button for the photographer to switch settings related to shooting operations. The power switch 109 is a switch for the photographer to operate the digital still camera 100 to turn on and off. The zoom adjustment lever 110 is a lever for the photographer to adjust the zoom magnification, and is configured to be rotatable within a predetermined angle range around the release button 108. In addition, the back surface portion 102 is provided with a liquid crystal monitor (not shown) that displays a captured image. Further, inside the digital still camera 100, a lens barrel 111 in which a lens group that forms an optical image of a subject is accommodated is disposed.

[2. Lens barrel configuration]
As shown in FIGS. 2 and 3, the lens barrel 111 includes a first lens group 210, a second lens group 220, a third lens group 230, a fourth lens group 240, a fifth lens group 250, and a sixth lens. A group 260 is arranged. Further, a shutter unit 270 is disposed between the third lens group 230 and the fourth lens group 240. The sixth lens group 260 is supported by a master flange 280, and an image sensor 290 is disposed on the master flange 280. As the image sensor 290, for example, a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) sensor is used.

  The first lens group 210 includes a first lens 211 serving as an objective lens, a reflecting prism 212 serving as a second lens, and a third lens 213, and these are bonded and fixed to a casing 214 constituting the lens barrel 111. It is fixed.

  The second lens group 220 is a zoom lens group, and the fourth lens 221, the fifth lens 222, and the sixth lens 223 are bonded and fixed and attached to the second lens group holding frame 224. The second lens group holding frame 224 is configured to move within the housing 226 of the lens barrel 111 by the second lens group driving means 225 disposed outside the lens barrel 111.

  The third lens group 230 includes a single seventh lens 231 and is supported and fixed to the housing 232.

  The fourth lens group 240 is a focus lens group, and includes an eighth lens 241 and a ninth lens 242 and is attached to the fourth lens group holding frame 243. The fourth lens group holding frame 243 is configured to move within the housing 245 of the lens barrel 111 by a fourth lens group driving unit 244 arranged outside the lens barrel 111.

  The fifth lens group 250 includes a single tenth lens 251 and is supported and fixed to the housing 252.

  The sixth lens group 260 is a camera shake correction lens group, is configured by the eleventh lens 261, and is attached to the sixth lens group holding frame 262. The sixth lens group holding frame 262 is configured to move within the housing 263 of the lens barrel 111 by sixth lens group driving means (not shown).

  Here, each of the casing 214, the casing 226, the casing 232, the casing 245, the casing 252, the casing 263, and the master flange 280 constituting the lens barrel 111 are arranged in the Z-axis direction shown in FIG. It is assembled so as to be parallel to the optical axis 300. In addition, you may comprise these housings integrally. An optical axis 310 shown in FIG. 3 is an optical axis in the Y-axis direction that is incident from the first lens 211 serving as an objective lens, and the optical axis 310 and the optical axis 300 intersect at a right angle on the same plane.

  Therefore, the light incident from the first lens 211 is the first lens group 210, the second lens group 220, the third lens group 230, the shutter unit 270, the fourth lens group 240, the fifth lens group 250, and further the sixth lens. The light passes through the group 260 and forms an image on the image sensor 290. At this time, the second lens group 220 moves on the optical axis 300 for zoom adjustment, and the fourth lens group 240 moves on the optical axis 300 for focus adjustment. Further, the sixth lens group 260 moves on the optical axis 300 and adjusts camera shake correction.

[3. Configuration of Moving Mechanism of Fourth Lens Group 240]
As shown in FIG. 4, the fourth lens group 240 is supported and fixed to the fourth lens holding frame 243. The fourth lens group holding frame 243 is integrally provided with a fourth lens group moving bearing portion 244. A guide shaft 420 is inserted into the fourth lens group moving bearing portion 244. The fourth lens group moving bearing portion 244 has a guide shaft 420 formed by a first bearing 244a provided in the upper portion (Z-axis negative direction) in the longitudinal direction and a second bearing 244b provided in the lower portion (Z-axis positive direction). Supported by the top. Thereby, the fourth lens group moving bearing portion 244 can slide on the guide shaft 420.

  The focus rack portion 410 is rotatably attached to and supported by the fourth lens holding frame 243 so that a predetermined angle can be taken. That is, a pinion (not shown) combined with the focus rack portion 410 is driven by the fourth lens group driving means 430 such as a stepping motor. Specifically, the focus rack portion 410 is biased to a pinion (not shown) by a spring (not shown). Therefore, the focus rack part 410 is combined with the pinion. In this way, the focus rack portion 410 moves up and down in the Z-axis direction. Further, the fourth lens group holding frame 243 moves up and down on the optical axis 300 in the Z-axis direction while being restricted in position by the guide shaft 420. In this way, focus adjustment is possible.

  A third bearing 245 is provided on the side surface of the fourth lens group holding frame 243 opposite to the fourth lens group moving bearing portion 244. The third bearing 245 is configured to be vertically movable in the Z-axis direction along a focus guide auxiliary shaft 422 that is integral with the housing of the fifth lens group 250 and provided along the Z-axis.

  As shown in FIG. 5A, the L8 lens 241 is bonded and fixed to the fourth lens group holding frame 243. In this embodiment, the L8 lens 241 is a lens made of glass.

  As shown in FIG. 5B, the L9 lens 242 is bonded and fixed to the fourth lens group holding frame 243. In this embodiment, the L9 lens 242 is a lens made of plastic. That is, the L9 lens 242 that is a plastic lens and the L8 lens 241 that is a glass lens are bonded and fixed so that the optical center (optical axis) is aligned with the fourth lens holding frame 243 that is the same lens frame.

  However, in such a lens group configuration, there is a case where an optical axis shift occurs between the glass lens and the plastic lens after the glass lens and the plastic lens are bonded and fixed. Also, optical axis misalignment may occur in performance tests under low temperature or high temperature environments. Such a shift of the optical axis between the lenses may cause a part of the subject image formed on the imaging surface of the imaging device 290 or a wide range of the resolution performance specification not being achieved. In other words, the quality of the captured image is degraded due to the deviation of the optical axis.

  Therefore, it is necessary to have a lens bonding configuration that can reduce the deviation of the optical axis.

[4. Lens adhesive configuration]
Next, main parts constituting the fourth lens group 240 will be described. The material of the L8 lens 241 shown in FIGS. 6A and 6B is glass. In the present embodiment, both surfaces of the L8 lens 241 are spherically processed. As shown in FIG. 6C, an L8 lens mounting surface 481 is formed at the radial end of the L8 lens 241.

  The material of the L9 lens 242 shown in FIGS. 7A and 7B is plastic. In this embodiment, both the L9 lens 242 are processed to be concave. The L9 lens 242 is formed by molding a plastic material for an optical lens using a mold. Therefore, there is a remaining gate portion 432 accompanying the outer diameter of the L9 lens 242. A pin abutting portion 431 for pushing the L9 lens 242 out of the mold is provided on the end surface in the positive direction of the Z axis of the L9 lens 242. More specifically, a lens attachment surface 433 is provided on the outer edge portion of the end surface of the L9 lens 242 in the negative Z-axis direction. Furthermore, the outer diameter end surface of the L9 lens 242 is configured by an L9 lens outer diameter contact surface 434 and an L9 lens outer diameter portion 435.

  The fourth lens group holding frame 243 shown in FIGS. 8A and 8B is formed of a polycarbonate containing glass fibers or a synthetic resin such as ABS. Further, as shown in FIG. 8C, the L9 lens receiving portion that is the lens height restricting portion, the L9 lens first adhesive reservoir 452, the L9 lens second adhesive reservoir 453, and the L9 lens that is the lens outer diameter restricting portion. An outer shape receiving portion 454 is provided, and the holding shapes of these L9 lenses 242 are provided in three places, and each is provided in the same phase. When the entire circumference of the L9 lens 242 is arbitrarily divided into two, at least one L9 lens outer diameter receiving portion 454 may be provided on each half circumference. According to such a configuration, the L9 lens 242 can be further stably fixed.

  As shown in FIG. 8B, three L8 lens attachment surface receiving portions 461 and three L8 lens adhesive reservoirs 462 are provided.

  Next, a method for bonding the L8 lens 241 and the L9 lens 242 to the fourth lens group holding frame 243 will be described.

  First, as shown in FIGS. 9A and 9C, the L9 lens 242 is disposed at a predetermined position of the fourth lens group holding frame 243. Next, the adhesive 470 is injected by a dispenser or the like into the L9 lens first adhesive reservoir 452, which is a supply portion having a wide interval from the radial end of the L9 lens 242. The adhesive 470 is an ultraviolet curable adhesive and desirably has a viscosity in the range of 1000 mPa · s to 100,000 mPa · s. The viscosity of the adhesive 470 is more preferably 40,000 mPa · s or more and 100,000 mPa · s or less. Here, in order to further facilitate the manufacture, it is desirable that the radial width of the adhesive reservoir 452 as viewed from the optical axis is larger than the tip diameter of the dispenser nozzle.

  Next, the adhesive 470 is a capillary tube in a space formed between the L9 lens second adhesive reservoir 453 and the L9 lens side surface portion 465, which is an adhesive portion having a narrow distance from the radial end portion of the L9 lens 242. Filled by phenomenon. The width of the L9 lens second adhesive reservoir as viewed from the optical axis 453 is preferably about 0.1 mm from the outer diameter portion 465 of the L9 lens. In this way, the L9 lens first adhesive reservoir 452 and the L9 lens second adhesive reservoir 453 constitute an adhesive reservoir.

  Next, the adhesive 470 is irradiated with ultraviolet rays, and the adhesive 470 is cured. In this manner, the L9 lens 242 is bonded and fixed to the fourth lens group holding frame 243.

  As shown in FIG. 9C, the position of the L9 lens 242 in the outer diameter direction is such that the L9 lens outer diameter receiving portion 454 and the L9 lens outer diameter contact surface 454 have a small gap of 0.01 mm or more and 0.03 mm or less. Open and fixed. The position of the L9 lens in the optical axis direction is fixed by bringing the L9 lens receiving portion 451 and the L9 lens mounting surface 433 into contact with each other.

  Here, since the adhesive 470 contracts due to ultraviolet curing, there is a possibility that the L9 lens 242 may be distorted. However, according to the present embodiment, the L9 lens receiving portion 451, the L9 lens first adhesive reservoir 452, the L9 lens second adhesive reservoir 453, and the L9 lens outer shape receiving portion 454 are integrally provided at the same position. (L9 lens fixing part 500). Therefore, volume shrinkage of the adhesive 470 due to ultraviolet curing is suppressed. Further, the external force acting on the L9 lens 242 due to the volume shrinkage of the adhesive 470 is caused by the L9 lens receiving portion 451 and the L9 lens outer diameter receiving portion 454 provided in the vicinity of the second adhesive reservoir 453 of the L9 lens. It is accepted. Therefore, distortion generated in the L9 lens 242 can be reduced.

  Further, the remaining gate portion 462 is inserted into a gate relief portion 455 provided in the fourth lens group holding frame 243. As a result, it is possible to prevent adhesion to the gate whose shape is not stable, and to stabilize the adhesion fixing accuracy and the adhesion strength.

  Next, as shown in FIG. 9B, the L8 lens attachment surface 481 is attached to the L8 lens receiving portion 461 of the fourth lens group holding frame 243, and the position of the L8 lens in the optical axis direction is fixed (L8 lens fixing portion). 502).

  Next, as shown in FIG. 9D, adhesive 472 is injected into three locations of the adhesive reservoir 462 of the L8 lens. The adhesive 472 is preferably the same as the adhesive 470. However, in view of the use of the digital still camera 100 in a high temperature or low temperature environment, the linear expansion coefficient after curing may be the same.

  Next, the position adjustment of the L8 lens 241 in the outer diameter direction is performed, and the relative position with the L9 lens 242 is adjusted to a predetermined specification. Thereafter, ultraviolet rays are irradiated to cure the adhesive 472. In this manner, the L9 lens 241 is bonded and fixed to the fourth lens group holding frame 243.

(Embodiment 2)
10A and 10B show a second embodiment.

  The L9 lens mounting surface 521 and the L8 lens adhesive reservoir 522 are integrally formed with respect to the angle in the lens circumferential direction of the L9 lens adhesive reservoir 512 formed integrally with the L9 lens mounting surface 511, and the optical axis The angle of arrangement in the lens circumferential direction is made to coincide with 300 when viewed from one incident light side. According to the present embodiment, in view of use of the digital still camera 100 in a high temperature or low temperature environment, an adhesive 472 injected into the L9 lens adhesive reservoir 512 after the L9 lens 242 and the L8 lens 241 are bonded and fixed, Due to the contraction of the adhesive 470 injected into the L8 lens adhesive reservoir 522, the movement directions of the L9 lens 242 and the L8 lens 241 are the same, so the amount of coaxial displacement between the lens centers of the L9 lens 242 and the L8 lens 241 is reduced. It has an effect of suppressing deterioration of optical performance such as resolution performance against temperature change.

[5. Summary]
The lens barrel 111 of the present embodiment has a fourth lens group 240. The fourth lens group 240 includes an L8 lens 241 and an L9 lens 242. The L8 lens 241 is bonded and fixed to the L8 lens fixing unit 502 so that the center of the lens is aligned with the optical axis. The L9 lens 242 is adhesively fixed to the L9 lens fixing unit 500 so that the lens center is aligned with the optical axis. The L8 lens fixing unit 502 and the L9 lens fixing unit 500 are integrally formed. The L9 lens fixing portion 500 includes at least three L9 lens outer diameter receiving portions 454 that come into contact with the radial ends of the L9 lens 242 so as to regulate the outer diameter of the L9 lens 242. Further, the L9 lens fixing portion 500 includes an L9 lens receiving portion 451 that is in contact with the end portion in the optical axis direction of the L9 lens so as to regulate the height of the L9 lens 242, and is integrally provided with the L9 lens outer diameter receiving portion 454. Further, the L9 lens fixing portion 500 includes an L9 lens first adhesive reservoir 452 integrated with the L9 lens outer diameter receiving portion 454. The L8 lens 241 and the L9 lens 242 are bonded and fixed with an adhesive 470 and an adhesive 472 that have the same linear expansion coefficient after curing.

  According to such a configuration, the L9 lens 242 and the L8 lens 241 are fixed by the adhesive 470 and the adhesive 472 having the same linear expansion coefficient even if the ambient environment such as temperature fluctuates. And the deviation of the optical center of the L8 lens 241 can be reduced.

  Therefore, when the plastic lens and the glass lens are used in the same lens group, it is possible to provide a lens barrel capable of reducing deterioration of the captured image quality even if the ambient environment such as temperature fluctuates.

(Other embodiments)
As described above, the embodiment of the present invention has been exemplified. However, the present invention is not limited to this. Therefore, other embodiments of the present invention will be collectively described below. In addition, this invention is not limited to these, It is applicable also to other embodiment modified suitably.

  In the embodiment, the example applied to the fourth lens group 240 having a focus function is shown. However, the present invention is not limited to this. For example, the present invention can be applied to the second lens group 220 having a zoom function. That is, in the same lens group, the present invention can be applied if a plastic lens and a glass lens are bonded and fixed to the same lens frame with their optical axes aligned. Therefore, the present invention can be applied to a straight-ahead optical system instead of the bending optical system as in the present embodiment.

  Furthermore, in the embodiment, the case where the plastic lens is a double D-cut lens has been exemplified. However, the present invention is not limited to this. The present invention can be applied regardless of the shape of the lens such as a D-cut lens or a circular lens.

  The lens barrel of the present invention is a lens that can reduce deterioration in image quality even when the surrounding environment such as temperature fluctuates when a plastic lens and a glass lens are used in the same lens group. A lens barrel can be provided. Therefore, the present invention is widely useful as a lens barrel of a portable device such as a lens interchangeable DSC (Digital Still Camera), a fixed lens DSC, or a movie, or a lens barrel of a television camera or a surveillance camera.

DESCRIPTION OF SYMBOLS 100 Digital still camera 101 Front part 102 Back part 103 Top part 104 Bottom part 105 Left side part 106 Right side part 107 Shooting mode switch button 108 Release button 109 Power switch 110 Zoom adjustment lever 111 Lens barrel 210 1st lens group 211 1st lens 212 Reflecting prism 213 3rd lens 214,226,232,245,252,263 Housing 220 2nd lens group 221 4th lens 222 5th lens 223 6th lens 224 2nd lens group holding frame 225 2nd lens group drive Means 230 Third lens group 231 7th lens 240 4th lens group 241 8th lens 242 9th lens 243 4th lens group holding frame 244 4th lens group driving means 250 5th lens group 251 10th lens 260 6th lens Group 261 11th lens 262 6th lens group holding frame 270 Shutter unit 280 Master flange 290 Image sensor 300, 310 Optical axis 410 Focus rack part 420 Guide shaft 422 Focus guide auxiliary shaft 431 Pin contact part 432 Gate escape part 433 L9 lens attachment Surface 434 L9 lens outer diameter contact surface 435 L9 lens outer diameter portion 451 L9 lens receiving portion 454 L9 lens outer diameter receiving portion 461 L8 lens mounting surface receiving portion 462 L8 lens adhesive reservoir 470, 472 Adhesive 481 L8 lens mounting surface 500 L8 lens fixing portion 502 L9 lens fixing portion 511 L9 lens mounting surface 512 L9 lens adhesive reservoir 513 Gate escape portion 521 L8 lens mounting surface 522 L8 lens adhesive reservoir

Claims (8)

A lens barrel having at least one lens group,
The lens group includes a glass lens, a plastic lens, and a lens holding frame,
The glass lens is adhesively fixed to the glass lens fixing portion so that the lens center is aligned with the optical axis,
The plastic lens is bonded and fixed to a plastic lens fixing portion,
The glass lens fixing part and the plastic lens fixing part are integrally formed on the lens holding frame by resin molding,
The plastic lens fixing portion includes at least three lens outer diameter regulating portions that come into contact with the radial end of the plastic lens so as to regulate the outer diameter of the plastic lens,
Furthermore, the plastic lens fixing portion includes at least three lens height regulating portions that come into contact with the optical axis direction end portion of the plastic lens so as to regulate the height of the plastic lens,
Furthermore, the plastic lens fixing portion includes at least three adhesive reservoir portions,
The plastic lens fixing part, the plastic lens outer diameter restricting part, the plastic lens height restricting part, and the adhesive reservoir part are formed close to each other,
The lens barrel, wherein the glass lens and the plastic lens are bonded and fixed to the lens holding frame with an adhesive. The lens barrel according to claim 1, wherein the adhesive that bonds and fixes the glass lens and the plastic lens uses the same adhesive. The lens barrel according to claim 1, wherein the adhesive that bonds and fixes the glass lens and the plastic lens uses an adhesive that has the same linear expansion coefficient after curing. The lens barrel according to claim 1, wherein the adhesive that bonds and fixes the glass lens and the plastic lens is an adhesive that has the same hardness after curing. The lens barrel according to claim 1, wherein an adhesive having the same contraction rate is used as the adhesive for bonding and fixing the glass lens and the plastic lens. 2. The lens barrel according to claim 1, wherein the adhesive reservoir portion includes an adhesive portion having a narrow interval with a radial end portion of the plastic lens and a supply portion having a wide interval between the radial end portions of the plastic lens. . 3. The lens barrel according to claim 1, wherein when the entire circumference of the plastic lens is arbitrarily divided into two equal parts, at least one lens outer diameter restricting portion is provided on each half circumference. 4. The adhesive reservoir for adhering and fixing the glass lens and the adhesive reservoir for adhering and fixing the plastic lens are each at least in the same lens circumferential direction when viewed from one entrance side with respect to the optical axis. The lens barrel according to any one of claims 1 to 7, wherein the lens barrel is integrally formed with the lens holding frame at three locations by resin molding.

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