JP5883260B2 - Lens barrel and imaging device - Google Patents

Description

  The present invention relates to a lens barrel and an imaging apparatus.

  Conventionally, as described in, for example, Patent Document 1 below, in a zoom lens having a two-group configuration, a cam cylinder is rotated with respect to a fixed cylinder, and both the first lens holding cylinder and the second lens holding cylinder are arranged. A configuration that moves in the optical axis direction is known.

JP-A-2005-352406

  However, the technique described in Patent Document 1 is configured to move the first lens holding cylinder in the optical axis direction with respect to the moving cylinder in order to adjust the focus. There was a problem that the manufacturing cost increased.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to be able to configure the lens barrel with a simple configuration and to easily adjust the focal position. It is an object of the present invention to provide a new and improved lens barrel and imaging device.

  In order to solve the above-described problems, according to an aspect of the present invention, a fixed cylinder that holds the first group lens and the second group lens so as to be movable in the optical axis direction, and is rotatable with respect to the fixed cylinder. And a rotating cylinder that moves the first group lens and the second group lens in the direction of the optical axis with rotation, and the rotating cylinder moves the first group lens in the direction of the optical axis. An angular position about the optical axis of the second rotating cylinder with respect to the first rotating cylinder, the first rotating cylinder and a second rotating cylinder that moves the second lens group in the optical axis direction There is provided a lens barrel including an adjustment unit for adjusting the angle.

  According to the above configuration, the rotating cylinder that moves the first group lens and the second group lens in the optical axis direction includes the first rotating cylinder that moves the first group lens in the optical axis direction, and the second group lens. The adjusting unit adjusts an angular position around the optical axis of the second rotating cylinder with respect to the first rotating cylinder. Accordingly, a zoom lens having a two-group configuration can be configured with a simple configuration without separately providing a focus adjustment tube.

  The second rotary cylinder is provided with an adjustment hole into which an eccentric pin is inserted for the adjustment, and the eccentric pin is located at a position corresponding to the adjustment hole of the first rotary cylinder. A groove into which the eccentric protrusion is inserted is provided. With this configuration, it is possible to adjust the angular position around the optical axis of the second rotating cylinder with respect to the first rotating cylinder by rotating the eccentric pin with respect to the adjustment hole.

  The second group lens is engaged with the fixed cylinder by a helicoid, and the second rotating cylinder rotates the second group lens to move in the optical axis direction as it rotates. With this configuration, the size in the vicinity of the second lens group can be minimized.

  A female helicoid is provided on the inner peripheral surface of the fixed cylinder, and the female helicoid is formed by straight-cutting a forming die. With this configuration, the accuracy of the angular position of the female helicoid with respect to the fixed cylinder can be greatly increased, and the interval between the first lens group and the second lens group can be defined with high accuracy.

  The second rotating cylinder includes a third rotating cylinder arranged on the outer periphery of the fixed cylinder and a fourth rotating cylinder arranged on the inner periphery of the fixed cylinder. With this configuration, it is possible to transmit the rotation of the fourth rotating cylinder to the second group lens even in a configuration in which the second group lens is engaged with the inside of the fixed cylinder.

  The adjusting unit adjusts an angular position around the optical axis of the third rotating cylinder with respect to the first rotating cylinder. With this configuration, the angular position around the optical axis of the third rotating cylinder relative to the first rotating cylinder can be adjusted, and as a result, the optical axis of the fourth rotating cylinder relative to the first rotating cylinder is centered. The angular position can be adjusted.

  The first group lens moves in the direction of the optical axis while rotating along the skew cam of the fixed cylinder as the first rotating cylinder rotates. With this configuration, since the positional accuracy in the optical axis direction of the first rotating cylinder with respect to the fixed cylinder can be relaxed, the manufacturing cost can be reduced.

  The lens barrel is applied to a pan focus zoom lens. With this configuration, it is possible to focus on a desired position by adjusting the angular position around the optical axis of the second rotating cylinder with respect to the first rotating cylinder.

  In order to solve the above-described problem, according to another aspect of the present invention, a fixed cylinder that holds the first group lens and the second group lens movably in the optical axis direction, and a rotation with respect to the fixed cylinder. A rotary cylinder that is movably provided and moves the first group lens and the second group lens in the direction of the optical axis with rotation, and the rotary cylinder has the optical axis of the first group lens. A first rotating cylinder that moves in the direction and a second rotating cylinder that moves the second lens group in the optical axis direction, and the optical axis of the second rotating cylinder with respect to the first rotating cylinder is the center. An imaging apparatus is provided that includes a lens barrel having an adjustment unit that adjusts an angular position and an imaging element having an imaging surface on which a subject image is formed by the first group lens and the second group lens. The

  According to the above configuration, the rotating cylinder that moves the first group lens and the second group lens in the optical axis direction includes the first rotating cylinder that moves the first group lens in the optical axis direction, and the second group lens. The adjusting unit adjusts an angular position around the optical axis of the second rotating cylinder with respect to the first rotating cylinder. Accordingly, a zoom lens having a two-group configuration can be configured with a simple configuration without separately providing a focus adjustment tube.

  The second rotary cylinder is provided with an adjustment hole into which an eccentric pin is inserted for the adjustment, and the eccentric pin is located at a position corresponding to the adjustment hole of the first rotary cylinder. A groove into which the eccentric protrusion is inserted is provided. With this configuration, it is possible to adjust the angular position around the optical axis of the second rotating cylinder with respect to the first rotating cylinder by rotating the eccentric pin with respect to the adjustment hole.

  The second group lens is engaged with the fixed cylinder by a helicoid, and the second rotating cylinder rotates the second group lens to move in the optical axis direction as it rotates. With this configuration, the size in the vicinity of the second lens group can be minimized.

  A female helicoid is provided on the inner peripheral surface of the fixed cylinder, and the female helicoid is formed by straight-cutting a forming die. With this configuration, the accuracy of the angular position of the female helicoid with respect to the fixed cylinder can be greatly increased, and the interval between the first lens group and the second lens group can be defined with high accuracy.

  The second rotating cylinder includes a third rotating cylinder arranged on the outer periphery of the fixed cylinder and a fourth rotating cylinder arranged on the inner periphery of the fixed cylinder. With this configuration, it is possible to transmit the rotation of the fourth rotating cylinder to the second group lens even in a configuration in which the second group lens is engaged with the inside of the fixed cylinder.

  The adjusting unit adjusts an angular position around the optical axis of the third rotating cylinder with respect to the first rotating cylinder. With this configuration, the angular position around the optical axis of the third rotating cylinder relative to the first rotating cylinder can be adjusted, and as a result, the optical axis of the fourth rotating cylinder relative to the first rotating cylinder is centered. The angular position can be adjusted.

  The first group lens moves in the direction of the optical axis while rotating along the skew cam of the fixed cylinder as the first rotating cylinder rotates. With this configuration, since the positional accuracy in the optical axis direction of the first rotating cylinder with respect to the fixed cylinder can be relaxed, the manufacturing cost can be reduced.

  The lens barrel is applied to a pan focus zoom lens. With this configuration, it is possible to focus on a desired position by adjusting the angular position around the optical axis of the second rotating cylinder with respect to the first rotating cylinder.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to comprise a lens barrel with a simple structure, the lens barrel and imaging device which can adjust a focus position easily can be provided.

It is a perspective view which shows the external appearance of a lens-barrel. It is a disassembled perspective view of a lens barrel. It is a schematic diagram which shows the cross section along the optical axis of a lens-barrel. It is a perspective view which shows the protrusion provided in the inner cylinder, and the rib provided in the 2nd group lens holding cylinder. It is a schematic diagram for demonstrating the function of a zoom lock pin. It is a schematic diagram which shows the case where a female helicoid is comprised with a 6-row helicoid. It is a schematic diagram which shows the case where a female helicoid is comprised with a 3 row | line | column helicoid. It is a perspective view which shows the eccentric pin used when adjusting a pan focus. It is a schematic diagram which shows a mode that pan focus adjustment is performed with an eccentric pin. It is a schematic diagram which shows a mode that pan focus adjustment is performed with an eccentric pin. It is a schematic diagram which shows the cross section in the position of the central axis of an eccentric pin in the state which inserted the eccentric pin. It is a schematic diagram which shows the cross section in the position of the central axis of an eccentric pin in the state which inserted the eccentric pin.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  First, a lens barrel 100 of an imaging apparatus according to an embodiment of the present invention will be described with reference to FIG. As an example, the lens barrel 100 according to the present embodiment can be used in an imaging device such as a surveillance camera.

  The lens barrel 100 is applied to a zoom lens having a two-group configuration. As an example, in the present embodiment, a case where the present invention is applied to a two-group configuration pan focus zoom lens will be described. A pan-focus zoom lens is a lens that can capture an image that is in focus from close to infinity, and has a wide focal length that is in focus from close to infinity. Can be changed from Tele to Tele.

  In the case of a varifocal zoom lens, when the focal length is moved by zooming, the focus is shifted. For this reason, when it is applied to a monitoring camera or the like, if zooming is performed after the camera is installed at a desired position, it is necessary to adjust the focus, and the work becomes complicated. On the other hand, in the case of a pan focus zoom lens, it is only necessary to perform zoom adjustment after installation of the camera, and since focus adjustment is not necessary, work at the time of installation can be greatly reduced.

  FIG. 1 is a perspective view showing the appearance of the lens barrel 100. FIG. 2 is an exploded perspective view of the lens barrel 100. FIG. 3 is a schematic diagram showing a cross section of the lens barrel 100 along the optical axis.

  As shown in FIGS. 1 to 3, the lens barrel 100 includes an outer cylinder 102, an intermediate cylinder 104, an inner cylinder 106, a fixed cylinder 108, a first group lens holding cylinder 110, and a second group lens holding cylinder 112. Configured. A first group lens 120 is attached to the first group lens holding cylinder 110. The second group lens holding cylinder 112 is equipped with a second group lens 122. The middle cylinder 104 is equipped with a zoom lock pin 118 that is held by a hand when the user rotates the outer cylinder 102 and locks the zoom position.

  As shown in FIG. 3, the middle cylinder 104 is engaged with the outer periphery of the fixed cylinder 108 so as to be rotatable. The outer cylinder 102 is fixed to the outer periphery of the middle cylinder 104 with screws 114, and the outer cylinder 102 and the middle cylinder 104 are integrated.

  As shown in FIGS. 2 and 3, three rectilinear grooves 104 a are provided on the inner peripheral surface of the middle cylinder 104. Further, three cam grooves 108a (oblique cams) are provided on the front side of the fixed cylinder 108.

  In the fixed cylinder 108, a first group lens holding cylinder 110 is inserted on the front side (subject side), and a second group lens holding cylinder 112 is inserted on the rear side. Three cam followers 110 a are provided on the outer periphery of the first group lens holding cylinder 110. The three cam followers 110 a are provided at positions corresponding to the three rectilinear grooves 104 a of the middle cylinder 104 and the three cam grooves 108 a of the fixed cylinder 108. Each of the three cam followers 110 a is inserted into a cam groove 108 a provided on the front side of the fixed cylinder 108, and is inserted into the three rectilinear grooves 104 a of the middle cylinder 104.

  The inner cylinder 106 is inserted behind the first group lens holding cylinder 110 in the fixed cylinder 108 and is rotatable with respect to the fixed cylinder 108. The fixed cylinder 108 is provided with three grooves 108b on the rear side of the cam groove 108a. Three screws 116 are inserted into the outer periphery of the outer cylinder 102, and each of the three screws 116 is inserted into the three grooves 108 b and fixed to the screw hole 106 a of the inner cylinder 106. Thereby, the outer cylinder 102 and the inner cylinder 106 are integrated by the screw 116. That is, the outer cylinder 102, the middle cylinder 104, and the inner cylinder 106 are integrated by the screw 114 and the screw 116. Since the screw 116 is inserted into a groove 108b formed to extend in the circumferential direction of the fixed cylinder 108, the outer cylinder 102, the middle cylinder 104, and the inner cylinder 106 rotate in an integrated state. can do.

  The inner cylinder 106 is provided with a protrusion 106a extending toward the rear side. The protrusion 106 a is engaged with a rib 112 a provided on the second group lens holding cylinder 112. A male helicoid 112 a is provided on the outer peripheral surface of the second group lens holding cylinder 112. The male helicoid 112a is engaged with a female helicoid 108c provided on the inner surface of the fixed cylinder 108 on the rear side. Thus, since the second group lens holding cylinder 112 is supported on the fixed cylinder 108 by helicoid, the outer diameter of the fixed cylinder 108 outside the second group lens holding cylinder 112 can be minimized. Accordingly, it is possible to reduce the outer diameter of the lens mount portion provided on the rear side of the lens barrel 100 (on the imaging element 130 side), and to achieve downsizing of the imaging apparatus.

  In FIG. 3, the imaging element 130 disposed on the rear side of the lens barrel 100 is shown together with the lens barrel 100. A subject image is formed on the imaging surface of the imaging element 130 by the first group lens 120 and the second group lens 122. The imaging apparatus according to the present embodiment includes a lens barrel 100 and an imaging element 130.

  FIG. 4 is a perspective view showing the protrusion 106 a provided on the inner cylinder 106 and the rib 112 a provided on the second group lens holding cylinder 112. As shown in FIG. 4, a groove 106 b is provided in the protrusion 106 a provided on the inner cylinder 106. The second group lens holding cylinder 112 is provided with a hole 112b, and a rib 112a is provided between the two holes 102b. The width of the groove 106b corresponds to the width of the rib 112a, and the groove 106b is inserted into the rib 112a and engaged with the rib 112a.

  FIG. 5 is a schematic diagram for explaining the function of the zoom lock pin 118. FIG. 5B is a schematic diagram showing a cross section of the lens barrel 100 at the position of the zoom lock pin 118, and shows a state in which the lens barrel 100 is viewed from the subject side. The cross section along -I 'is shown. As shown in FIG. 5B, the male screw 118 b provided on the zoom lock pin 118 is engaged with the female screw 104 b provided on the middle cylinder 104. When the user tightens the zoom lock pin 118, the tip of the zoom lock pin 118 comes into contact with the outer peripheral surface of the fixed cylinder 108, and the middle cylinder 104 is fixed to the fixed cylinder 108. On the other hand, when the user loosens the zoom lock pin 118, the tip of the zoom lock pin 118 is separated from the outer periphery of the fixed cylinder 108. Accordingly, by operating the zoom lock pin 118, the user can rotate the middle cylinder 104 and can rotate the outer cylinder 102 and the inner cylinder 106 integrated with the middle cylinder 104.

  FIG. 5B shows a cross section at a position where the projection 106 a of the inner cylinder 106 is inserted into the hole 112 b of the second lens group holding cylinder 112. As shown in FIG. 5, the protrusion 106a is inserted into the hole 112b, whereby the groove 106b is inserted into the rib 112a.

  In the above configuration, the user can rotate the integrated outer cylinder 102, middle cylinder 104, and inner cylinder 106 by loosening the zoom lock pin 118 and operating the zoom lock pin 118. When the middle cylinder 104 rotates, the rectilinear groove 104a of the middle cylinder 104 rotates about the optical axis, so that the three cam followers 110a of the first group lens holding cylinder 110 follow the cam grooves 108a of the fixed cylinder 108. Move. Accordingly, the first lens group holding cylinder 110 moves in the optical axis direction while rotating along the cam groove 108a.

  When the inner cylinder 106 is rotated, the groove 106b of the inner cylinder 106 is engaged with the rib 112a of the second group lens holding cylinder 112, so that the second group lens holding cylinder 112 rotates together with the inner cylinder 106. . Since the male helicoid 112a is engaged with the female helicoid 108c of the fixed cylinder 108, the second group lens holding cylinder 112 moves in the optical axis direction as it rotates. At this time, the inner cylinder 106 rotates without moving in the optical axis direction, and the second group lens holding cylinder 112 moves in the optical axis direction while rotating by the male helicoid 112a and female helicoid 108c. The relative position of the rib 112a in the optical axis direction changes.

  Therefore, according to the present embodiment, by rotating the zoom lock pin 118 of the outer cylinder 102 with a very simple configuration, the first group lens holding cylinder 110 and the second group lens holding cylinder 112 are moved in the optical axis direction. It is possible to move to. At this time, the movement amount in the optical axis direction of the first group lens holding cylinder 110 by the cam groove 108a and the movement amount in the optical axis direction of the second group lens holding cylinder 112 by the male helicoid 112a and the female helicoid 108c are different. The first group lens holding cylinder 110 and the second group lens holding cylinder 112 move in the optical axis direction while the relative positions in the optical axis direction change.

  Further, the cam follower 110a of the first group lens holding cylinder 110 moves along the cam groove 108a provided in the fixed cylinder 108, and is engaged with the rectilinear groove 104a for the rotating middle cylinder 104. Therefore, even if the middle cylinder 104 moves relative to the fixed cylinder 108 in the optical axis direction, the position of the first group lens holding cylinder 110 in the optical axis direction is accurately defined by the cam groove 108a. Similarly, the position of the second group lens holding cylinder 112 in the optical axis direction is defined by the angular position of the male helicoid 112a with respect to the female helicoid 108c, and even if the position of the inner cylinder 106 in the optical axis direction is moved by the backlash. The position of the second group lens holding tube 112 in the optical axis direction is accurately defined by the female helicoid 108c and the male helicoid 112a.

  Therefore, the integrated outer cylinder 102, middle cylinder 104, and inner cylinder 106 can be defined with a certain degree of margin in the position in the optical axis direction. Specifically, since the screw 116 passes through the groove 108b of the fixed cylinder 108, the positions of the integrated outer cylinder 102, middle cylinder 104, and inner cylinder 106 in the optical axis direction can be defined. The movement of the integrated outer cylinder 102, middle cylinder 104, and inner cylinder 106 in the optical axis direction does not affect the positions of the first group lens holding cylinder 110 and the second group lens holding cylinder 112. Accordingly, it is possible to provide a margin for the width of the groove 108b with respect to the screw 116, and it is not necessary to increase the accuracy regarding the position of the groove 108b, the position of the screw 116, etc. more than necessary, and the manufacturing cost can be reduced.

  Further, since the second group lens holding cylinder 112 is engaged with the fixed cylinder 108 by the male helicoid 112a, the outer diameter of the inner cylinder 106 is not engaged with the fixed cylinder 108, and high accuracy is not required. It becomes. Therefore, the manufacturing cost can be reduced.

  In the above configuration, the outer cylinder 102, the middle cylinder 104, and the inner cylinder 106 rotate together. Here, in the present specification and claims, the integrated outer cylinder 102, middle cylinder 104, and inner cylinder 106 are referred to as a “rotary cylinder”, and the intermediate cylinder 104 is referred to as a “first rotary cylinder”. The integrated outer cylinder 102 and inner cylinder 106 are referred to as a “second rotating cylinder”. Further, in the “second rotating cylinder”, the outer cylinder 102 is referred to as a “third rotating cylinder”, and the inner cylinder 106 is referred to as a “fourth rotating cylinder”.

  Next, the configuration of the female helicoid 108c of the fixed cylinder 108 will be described. 6 and 7 are cross-sectional views showing the configuration of the female helicoid 108c, showing a cross section along the optical axis. Here, FIG. 6 shows a case where the female helicoid 108c is constituted by six helicoids, and FIG. 7 shows a case where the female helicoid 108c is constituted by three helicoids. When the female helicoid 108c is composed of six helicoids as shown in FIG. 6, the helicoid start point and end point overlap at the angular position. Therefore, in order to form the helicoid of FIG. You have to unscrew the mold you want. In this case, the phase variation of the female helicoid 108c with respect to the cam groove 108a of the first group (the variation of the angular position with the optical axis as the center) becomes large. As a result, the first group lens holding cylinder 110 and the second group lens holding cylinder The error of the relative position of 112 becomes large.

  On the other hand, when the female helicoid 108c is composed of three helicoids as shown in FIG. 7, the helicoid start point P1 and end point P2 do not overlap at an angular position, so there is no need to rotate the mold and straighten the mold. Can be removed. As a result, the dimensional error of the female helicoid 108c with respect to the cam groove 108a can be minimized, so that if the lens has a deep focal depth, it is not necessary to adjust the pan focus. In addition, since the pan focus adjustment margin can be set small even with a lens having a shallow focal depth, the degree of freedom in designing the lens barrel can be greatly increased.

  Next, a method for adjusting the distance between the first group and the second group will be described. As described above, the lens barrel 100 of the present embodiment can be applied to a pan focus zoom lens, and can capture an image in a focused state in the entire region from close to infinity. On the other hand, the positions of the first lens group 120 and the second lens group 122 vary depending on component tolerances. Therefore, when the lens barrel 100 is assembled, the imaging lens 130 is in focus on the imaging surface. It is assumed that there is not. For this reason, the positions of the first lens group 120 and the second lens group 122 are adjusted so as to adjust the focus on the imaging surface.

  As described above, the outer cylinder 102, the middle cylinder 104, and the screw 114 are integrated. As shown in FIG. 1 and FIG. 5A, the screw 114 fixes the middle cylinder 104 to the outer cylinder 102 by the end flange being in close contact with the surface 104 c of the middle cylinder 104. Here, the size of the surface 104c is formed larger than the flange at the end of the screw 114, and is configured so that the position where the screw 114 is fixed on the surface 104c can be adjusted. Thereby, it is possible to relatively adjust the angular position around the optical axis of the middle cylinder 104 with respect to the outer cylinder 102.

  When the angular position of the middle cylinder 104 with respect to the outer cylinder 102 changes, the inner cylinder 106 is fixed with respect to the outer cylinder 102. As a result, the angular position of the middle cylinder 104 and the inner cylinder 106 about the optical axis changes. To do. The position of the first group lens holding cylinder 110 in the optical axis direction is defined by the angular position of the rectilinear groove 104a of the middle cylinder 104, and the position of the second group lens holding cylinder 112 is determined by the angular position of the groove 106b of the inner cylinder 106. Since the position in the direction is defined, if the relative angular position of the middle cylinder 104 and the inner cylinder 106 changes, the relative position in the optical axis direction of the first group lens holding cylinder 110 and the second group lens holding cylinder 112 Changes. Therefore, by adjusting the position where the screw 114 is fixed on the surface 104c, the relative positions of the first group lens holding tube 110 and the second group lens holding tube 112 in the optical axis direction can be adjusted.

  When applied to a pan-focus zoom lens as in the present embodiment, in order to obtain a focused state in all zoom ranges from close to infinity, the first group at a predetermined zoom position (for example, the wide end) The distance between the lens 120 and the second group lens 122 is set according to the design value, and the first group lens 120 and the second group lens 122 are arranged at the position according to the design value. On the other hand, each component that defines the position of the first group lens 120 and the second group lens 122 in the optical axis direction has a dimensional error in manufacturing, and therefore, the distance between the first group lens 120 and the second group lens 122. And the case where the position does not become the design value is assumed. Even in such a case, according to the lens barrel 100 of the present embodiment, the relative angular position of the middle cylinder 104 with respect to the outer cylinder 102 is adjusted by adjusting the position where the screw 114 is fixed on the surface 104c. Therefore, the first group lens 120 and the second group lens 122 can be adjusted to desired positions, and a pan focus state can be obtained in which the focal point is in the entire range from the nearest to infinity.

  As described above, the adjusting portion that adjusts the angular position around the optical axis of the middle cylinder 104 with respect to the outer cylinder 102 is provided by the screw 114 engaged with the outer cylinder 102 and the surface 104 c of the middle cylinder 104.

  In particular, with the increase in the number of pixels of the image sensor 130, higher accuracy is required for the distance between the first group and the second group. As an adjustment method, the position of the first group lens 120 is fixed to a predetermined position by the zoom lock pin 118, and then the second group lens 122 is adjusted to a predetermined position by the adjustment unit. Alternatively, after the position of the second group lens 122 is fixed to a predetermined position, the first group lens 120 may be adjusted to a predetermined position by the adjustment unit. As an example, the pan focus zoom lens of the present embodiment is configured so that when a 2 m subject is focused, the entire range from close to infinity is focused.

  In addition, by adjusting the positions of the first group lens 120 and the second group lens 122 by the adjustment unit, it is possible to perform focus adjustment even in a zoom lens other than the pan focus. Therefore, the lens barrel 100 of the present embodiment is not limited to application to a pan focus zoom lens.

  The pan focus adjustment method will be described in detail below. FIG. 8 is a perspective view showing the eccentric pin 200 used when adjusting the pan focus. At the tip of the eccentric pin 200, a protrusion 200a is provided at a position eccentric from the central axis. Further, an outer peripheral surface 200b having a predetermined diameter is provided at the tip of the eccentric pin 200.

  As shown in FIG. 1, the outer cylinder 102 is provided with an adjustment hole 102c into which the eccentric pin 200 is inserted. The inner diameter of the hole 102 c corresponds to the outer diameter of the outer peripheral surface 200 b of the eccentric pin 200. A groove 104d is provided at a position corresponding to the hole 102c on the outer peripheral surface of the middle cylinder 104.

  FIG. 9 and FIG. 10 are schematic diagrams showing how pan focus adjustment is performed by the eccentric pin 200. When adjusting the pan focus, as shown in FIGS. 9 and 10, the eccentric pin 200 is inserted into the adjustment hole 102c, and the protrusion 200a is engaged with the groove 104d. Then, in this state, the eccentric pin 200 is rotated to adjust the relative angular position around the optical axis of the outer cylinder 102 with respect to the middle cylinder 104.

  11 and 12 are schematic views showing a cross section at the position of the central axis of the eccentric pin 200 in a state where the eccentric pin 200 is inserted. Here, FIG. 11 shows a cross section along the optical axis (cross section along the alternate long and short dash line II-II ′ in FIG. 9), and FIG. 10 shows a cross section along the direction perpendicular to the optical axis (in FIG. A cross section taken along the alternate long and short dash line III-III ′ is shown. As shown in FIG. 9, when the eccentric pin 200 is inserted into the adjustment hole 102c, the outer peripheral surface 200b of the eccentric pin 200 engages with the adjustment hole 102c so as to be rotatable. When the eccentric pin 200 is rotated with the protrusion 200a of the eccentric pin 200 engaged with the groove 104d of the middle cylinder 104, the protrusion 200a of the eccentric pin 200 is eccentric with respect to the center of the hole 102c. Therefore, the position of the groove 104d moves relative to the hole 102c. Thereby, the middle cylinder 104 provided with the groove 104d can be rotated around the optical axis with respect to the outer cylinder 102 provided with the hole 102c.

  At the time of adjustment, the screw 114 is loosened, the eccentric pin 200 is rotated to adjust the angular position of the middle cylinder 104 with respect to the outer cylinder 102 to a desired position, and then the outer cylinder 102 is tightened by tightening the screw 114. The angle position of the middle cylinder 104 with respect to is fixed. During adjustment, an image pickup device (CCD sensor, CMOS sensor, or the like) on which a subject image is formed by the first group lens holding tube 110 and the second group lens holding tube 112 while rotating the eccentric pin 200 is used. ) Is detected on the imaging surface, and the screw 114 is tightened at the most focused position. Thereby, it is possible to adjust to a pan focus state in which the focus is in the entire range from the close range to infinity.

  The adjustment is not limited to the method using the eccentric pin 200, and various methods can be used as long as the relative angular position of the outer cylinder 102 and the middle cylinder 104 can be adjusted.

  As described above, according to the present embodiment, the lens barrel 100 can have a simple barrel structure, the assembly workability can be improved, and the manufacturing cost can be reduced. Further, the configuration in which the relative angular position of the outer cylinder 102 and the middle cylinder 104 can be adjusted makes it possible to finely adjust the distance between the first group lens 120 and the second group lens. Therefore, the position of the focal point can be adjusted with high accuracy, and the pan focus adjustment in the pan focus zoom lens can be easily performed.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

100 lens barrel 102 outer cylinder 102c hole 104 middle cylinder 104d groove 106 inner cylinder 108 fixed cylinder 108a cam groove 108c female helicoid 110 first group lens holding cylinder 112 second group lens holding cylinder 112a male helicoid 120 first group lens 122 first 2 group lens 200 Eccentric pin 200a Protrusion

Claims (16)

A fixed cylinder that holds the first group lens and the second group lens movably in the optical axis direction;
The provided rotatably relative to the fixed cylinder, and a rotary cylinder Before moving in the optical axis direction of the first lens group and the second lens group with the rotation,
The rotary cylinder includes a first rotary cylinder Before moving the first lens group in the optical axis direction with the rotation, the light of the first rotary cylinder and the second lens group rotates together and a second rotary cylinder Before moving axially,
A lens barrel, comprising: an adjustment unit that adjusts an angular position around the optical axis of the second rotating cylinder with respect to the first rotating cylinder. The second rotating cylinder is provided with an adjustment hole into which an eccentric pin is inserted for the adjustment,
2. The lens mirror according to claim 1, wherein a groove into which an eccentric protrusion of the eccentric pin is inserted is provided at a position corresponding to the adjustment hole of the first rotating cylinder. Tube.   The second group lens is engaged with the fixed cylinder by a helicoid, and the second rotating cylinder rotates and moves the second group lens in the optical axis direction as it rotates. The lens barrel according to claim 1. Female helicoid is provided on the inner peripheral surface of the fixed cylinder, the female helicoid is engaged with the male helicoid of the second lens group, characterized in that it is shaped by straight removal from the mold, according to claim 3 The lens barrel described.   The second rotating cylinder includes a third rotating cylinder disposed on an outer periphery of the fixed cylinder and a fourth rotating cylinder disposed on an inner periphery of the fixed cylinder. Item 5. The lens barrel according to any one of Items 1 to 4.   The lens barrel according to claim 5, wherein the adjustment unit adjusts an angular position around the optical axis of the third rotating cylinder with respect to the first rotating cylinder.   2. The first group lens according to claim 1, wherein the first group lens moves in an optical axis direction while rotating along a skew cam of the fixed cylinder as the first rotating cylinder rotates. Lens barrel.   The lens barrel according to claim 1, wherein the lens barrel is applied to a pan focus zoom lens. A fixed cylinder that holds the first group lens and the second group lens so as to be movable in the optical axis direction, and is provided so as to be rotatable with respect to the fixed cylinder. has a rotary cylinder Before moving the lens group in the optical axis direction, wherein the rotary cylinder has a first rotary cylinder Before moving the first lens group in the optical axis direction with the rotation, the first and a first rotating cylinder and the second rotary cylinder which rotates integrally Before moving the second lens group along the optical axis, the optical axis of the second rotary cylinder with respect to the first rotary cylinder A lens barrel having an adjustment unit for adjusting the angular position as a center;
An imaging element having an imaging surface on which a subject image is formed by the first group lens and the second group lens;
An imaging apparatus comprising: The second rotating cylinder is provided with an adjustment hole into which an eccentric pin is inserted for the adjustment,
The imaging apparatus according to claim 9, wherein a groove into which an eccentric protrusion of the eccentric pin is inserted is provided at a position corresponding to the adjustment hole of the first rotating cylinder. .   The second group lens is engaged with the fixed cylinder by a helicoid, and the second rotating cylinder rotates and moves the second group lens in the optical axis direction as it rotates. The imaging device according to claim 9. Female helicoid is provided on the inner peripheral surface of the fixed cylinder, the female helicoid is engaged with the male helicoid of the second lens group, characterized in that it is shaped by straight removal from the mold, according to claim 11 The imaging device described.   The second rotating cylinder includes a third rotating cylinder disposed on an outer periphery of the fixed cylinder and a fourth rotating cylinder disposed on an inner periphery of the fixed cylinder. Item 13. The imaging device according to any one of Items 9 to 12.   The imaging device according to claim 13, wherein the adjustment unit adjusts an angular position around the optical axis of the third rotating cylinder with respect to the first rotating cylinder.   10. The first group lens according to claim 9, wherein the first group lens moves in the direction of the optical axis while rotating along the skew cam of the fixed cylinder as the first rotating cylinder rotates. Imaging device.   The image pickup apparatus according to claim 9, wherein the lens barrel is applied to a pan focus zoom lens.

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