JP6465584B2 - Lens barrel and optical apparatus having the same - Google Patents

Description

  The present invention relates to a lens barrel and an optical apparatus having the same.

  Conventionally, there are optical devices in which a lens is mounted on a lens barrel such as a camera or a projector, but they are used in various states. For example, a camera lens or the like is also used to take a vertically long image after being rotated by 90 ° from a normal horizontally long shooting state. In addition, a considerable percentage of projectors are used in a state in which they are suspended from the ceiling (suspended from the ceiling) with the front and back reversed.

  When changing to such various states, the posture and position of the internal lens group may fluctuate to deteriorate image quality. In particular, both cameras and projectors have been improved in image quality, and even slight fluctuations in the internal lens group have become unacceptable. In order to solve this problem, there has been proposed a structure in which a moving barrel is moved away by a spring and a ball and a play is removed with respect to a fixed barrel (Patent Document 1).

  As another conventional technique, there is a projection lens of a general projector in which a cam ring is laid out inside a fixed barrel as an inner cam ring (inner cam structure).

JP 2011-017769 A

  However, in order to provide a side-by-side structure as in Patent Document 1, it must be provided between the lens barrels, and further, it must be disposed at a position that does not hinder the moving member that rotates or moves straight. This leads to an increase in the size of the device. Further, when assembling the one-sided spring, care must be taken so that interference does not occur, and there are some that cannot be partly aligned depending on the layout of the cam ring.

  Further, when the cam ring described above is laid out inside the fixed lens barrel, the backlash removal structure in this layout increases the size of the apparatus, and a structure for incorporating a leaf spring for shifting it away may be provided. It was difficult.

  An object of the present invention is to provide a lens barrel and an optical apparatus having the same that can suppress fluctuations in an internal lens group without increasing the size.

  In order to achieve the above object, a lens barrel according to the present invention includes a lens frame that holds a lens group, a fixed housing that holds the lens frame, an inner side of the fixed housing, and the lens frame. A cam member for controlling the advancement and retraction of the cam member in the optical axis direction, and the fixed housing has an extension part extending to the inside of the cam member, and the cam member is interposed between the extension part and the cam member. An urging member for urging the fixed housing side is provided.

  Further, another lens barrel according to the present invention includes a first lens frame that holds the first lens group, a second lens frame that holds the second lens group, and the first lens. A first fixed housing that holds the frame, a second fixed housing that holds the second lens frame, and the first and second fixed housings, and the lens group is positioned on the optical axis. A cam member that advances and retracts in a direction, and the first fixed housing has a first extending portion that extends to the inside of the cam member at one end in the optical axis direction of the cam member. The second fixed housing has a second extending portion extending to the inside of the cam member at the other end portion in the optical axis direction of the cam member, and the first extending portion, the cam member, A first urging member for urging the cam member toward the first fixed housing is provided between Wherein said providing the second biasing member for biasing the cam member to the side of the second fixed housing between the cam member and the.

  ADVANTAGE OF THE INVENTION According to this invention, the lens barrel which can suppress the fluctuation | variation of an internal lens group, and an optical apparatus having the same can be provided, without enlarging.

It is sectional drawing of a lens barrel provided with the lens unit which concerns on embodiment of this invention. It is a right view (back view) of a lens barrel provided with a lens unit according to an embodiment of the present invention. It is AA sectional drawing of a lens barrel provided with the lens unit which concerns on embodiment of this invention. It is BB sectional drawing of a lens barrel provided with the lens unit which concerns on embodiment of this invention. 1 is a block diagram of an optical system related to a projector apparatus as an optical apparatus using a lens barrel according to an embodiment of the present invention.

   Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(Optical equipment)
FIG. 5 is a block diagram of an optical system related to a projector apparatus as an optical apparatus using the lens barrel according to the embodiment of the present invention as a projection optical system. In FIG. 5, the projector apparatus 100 includes a light source 101, dichroic mirrors 102 and 103, a mirror 104, polarizing beam splitters 105, 106, and 107, and liquid crystal panel elements 108, 109, and 110. In addition, an X prism 111, a luminance wheel a112, a luminance wheel b113, and a projection lens system 114 as a projection optical system are provided.

The light source 101 is a light source that outputs white light, such as an ultra-high pressure mercury lamp or a xenon lamp. White light from the light source 101 is separated by the dichroic mirror 102 into green (hereinafter referred to as G) component light, red (hereinafter referred to as R), and blue (hereinafter referred to as B) component light. The R and B component lights are supplied to the dichroic mirror 103 and separated into R component light and B component light.
The separated G, R, and B component lights are supplied to polarization beam splitters 105, 106, and 107, respectively. The G, R, and B component lights are supplied from the polarizing beam splitters 105, 106, and 107 to the liquid crystal panel elements 108, 109, and 110, respectively.

  The polarization of the G, B, and R component lights is controlled by the respective liquid crystal panel elements according to the input video signal, and returns to the polarization beam splitters 105, 106, and 107 again. Then, the polarization beam splitters 105, 106, and 107 separate the component light supplied to the X prism 111 as projection light and the component returning to the light source direction according to the polarization state. The X prism combines the respective G, R, and B component lights and supplies them to the projection lens system 114 as synthesized light. The projection lens system 114 projects the supplied combined light onto a screen or the like and displays an image.

  Note that the luminance wheel a112 and the luminance wheel b113 in FIG. 5 have an area that transmits light and an area that blocks light, as known in Japanese Patent Application Laid-Open No. 2014-041227, and the projection light is transmitted and blocked by rotating. It is a shading rate adjusting member that creates a state.

(Lens barrel)
The projection lens system 114 in FIG. 5 will be described in detail below as a lens unit. FIG. 1 is a cross-sectional view of a lens barrel including a lens unit having a five-group configuration according to an embodiment of the present invention. Reference numeral 1 denotes a fixed group, 2 denotes a second group that advances and retreats in the optical axis direction, 3 denotes a third group that advances and retreats in the optical axis direction, 4 denotes a fourth group that advances and retreats in the optical axis direction, and 5 denotes a forward and backward movement in the optical axis direction. Group (final group).

  Reference numerals 6 to 10 denote lens frame bodies. Reference numeral 6 denotes a first group frame as a fixed frame for holding the first group. Reference numeral 7 denotes a second group frame for holding the second group. Reference numeral 8 denotes a third group frame for holding the third group. A 4-group frame for holding groups 10 is a 5-group frame for holding groups 5. Reference numeral 11 denotes a fixed barrel as a fixed housing for holding all the lens groups (1st group to 5th group), and 12 denotes a cam ring as a cam member for controlling advance and retreat of each of the 2nd group to 5th group in the optical axis direction. is there.

  A cam roller 15 as an engaging member corresponding to each of the four lens frame bodies shown in FIG. 1 includes a straight groove (not shown) in the optical axis direction provided in the fixed barrel 11 and light provided in the cam ring 12. It engages with a cam groove (not shown) that intersects in the axial direction. Then, by rotation of the cam ring 12, the second group frame 7, the third group frame 8, the fourth group frame 9, and the fifth group frame 10 as lens frames are controlled to advance and retreat in the optical axis direction. Reference numeral 16 denotes a corobis as a holding member for holding the lens frame body and holding the cam roller 15 so that the cam roller 15 does not fall out and loosen. The above-described cam rollers 15 and 16 are fixed to three each of the second group frame to the fifth group frame (120 degree intervals around the optical axis).

  Here, the cam ring 12 is disposed inside the fixed barrel 11 and forms an inner cam ring (inner cam structure). Reference numeral 13 denotes a focus ring for rotating the cam ring 12 from the front of the lens unit, and is held by the fixed barrel 11 so as to be able to rotate and slide. A focus pin 14 transmits the rotation of the focus ring 13 to the cam ring 12 and is fixed to the outer periphery of the cam ring 12.

  Reference numeral 17 denotes a biasing spring (described in detail later) as an urging member for urging the cam ring 12 toward the fixed barrel 11 as a fixed housing, and two pieces (between the fixed barrel 11 and the cam ring 12) ( The angle direction is 120 degrees around the optical axis. Reference numeral 18 denotes a first group auxiliary frame as a fixed frame for holding the first group frame 6, and reference numeral 18 a denotes an extending portion of the first group auxiliary frame 18 for holding the biasing spring 17.

(Aligned structure)
Hereinafter, the side-by-side structure in this embodiment using the side-by-side spring will be described in detail. First, as an assembling procedure, the cam ring 12 is inserted into the fixed barrel 11, the second group frame 7, the third group frame 8, the fourth group frame 9, and the fifth group frame 10, which are lens frames, are attached to the cam rollers 16 and the corobis 15. The first group auxiliary frame 18 is attached after this. In this state, since the cam ring 12 has a degree of freedom, the center of rotation is not determined. Then, as described later, after the one-side spring 17 is assembled, the first group frame 6 is assembled and the focus ring 13 is mounted.

  Next, a side-by-side structure when viewed from the optical axis direction will be described. FIG. 2 is a view of the lens unit as viewed from the fifth group side which is the final group. In the figure, the direction perpendicular to the paper plane, which is the optical axis direction, is represented as YC, the right direction within the paper plane is represented as XC, and the upward direction within the paper plane is represented as ZC.

  The fixed barrel 11 is provided with two openings 11b in an angular direction of 120 degrees around the optical axis, from which a biasing spring 17 can be inserted. The cam ring 12 is offset in the outer circumferential direction by assembling the offset springs 17 at two locations in the opening 11b opened at three equal intervals (120 degree intervals around the optical axis). The center of rotation is determined in one place.

  The length of the opening 11b in the optical axis direction is preferably longer than the length of the biasing spring 17 in the optical axis direction. This is because the one-sided spring 17 can be protected by being buried (not exposed) from the opening 11b.

  FIG. 3 shows a cross section AA in FIG. In FIG. 3, the bias spring 17 (first biasing member) is inserted into the opening 11b provided in the fixed barrel 11 (first fixed housing), and the inner diameter portion of the opposing cam ring 12 is It is a figure which understands the structure biased and biased to the 1st fixed housing | casing side.

  Here, reference numeral 11 a denotes an extending portion that extends from the fixed barrel 11 and extends to the inside from the cam ring 12. That is, in FIG. 3 showing the sectional view AA, the cam ring 12 has a fixed barrel 11 having an inner diameter larger than the outer diameter of the cam ring 12 and an outer diameter smaller than the inner diameter of the cam ring 12 when viewed from the optical axis direction. And the extension portion of the fixed lens barrel 11. Here, the position of the extending portion 11a in the optical axis direction is the end position (one end position) in the longitudinal direction (optical axis direction) of the cam ring 12, and the cam roller 16 is retracted in the optical axis direction. No (does not collide) in a surplus space (dead space).

  If the cam roller 16 is retracted to the extending part 11a, the cam groove is cut so far in the cam ring 12, so that the cam ring 12 has very low rigidity and no accuracy. Therefore, there is no such cam ring, and the position where the extending portion 11a is always provided is a position in the surplus space.

As described above, the one end position in the longitudinal direction (optical axis direction) of the cam ring 12 is provided with a side-by-side structure using the extending portion 11a, but the longitudinal direction (optical axis direction) of the cam ring 12 is provided. ) Is also provided with a side-by-side structure using the extending portion 18a.
That is, FIG. 4 shows a cross section BB in FIG. In FIG. 4, the one-sided spring 17 (second urging member) is inserted into an opening (not shown) provided in the first group auxiliary frame 18 (second fixed housing), and the opposite cam ring 12 is inserted. It is a figure which understands the structure which urges | biases the inner diameter part of this to the 2nd fixed housing | casing side, and is shifted.

  Here, 18 a is an extending portion extended from the first group auxiliary frame 18 and extends to the inside from the cam ring 12. That is, in FIG. 4 showing the cross section B-B, the cam ring 12 has a first group auxiliary frame 18 having an inner diameter larger than the outer diameter of the cam ring 12 and an outer diameter smaller than the inner diameter of the cam ring 12 when viewed from the optical axis direction. And the extended portion 18a of the first group auxiliary frame 18. Here, the position of the extending portion 18a in the optical axis direction is the end position (the other end position) in the longitudinal direction (optical axis direction) of the cam ring 12, and the cam roller 16 is retracted in the optical axis direction. No (does not collide) in a surplus space (dead space).

  Then, the cam ring 12 is assembled by assembling the biasing springs 17 at two locations in the opening (not shown) opened at three locations (120 degree intervals around the optical axis) in the first group auxiliary frame 18. Are shifted to the outer circumferential direction, and the rotation center of the cam ring 12 is determined at one place.

  Here, at both ends of the cam ring 12 in the longitudinal direction (optical axis direction), it is preferable that the shifting directions by the first and second urging members coincide when viewed from the optical axis direction.

  In this way, by assembling the bias springs 17 at both end positions in the longitudinal direction (optical axis direction) of the cam ring 12, the cam ring 12 is offset in the outer circumferential direction, and the rotation center of the cam ring 12 is Determined in one place. As a result, the accuracy of the fifth group frame 10, the fourth group frame 9, the third group frame 8, and the second group frame 7 in the advance and retreat in the optical axis direction improves.

(Effect of this embodiment)
As described above, according to the present embodiment, the cam ring side-by-side structure is constructed using the surplus space created at both ends of the cam ring, and a more accurate lens unit can be created. In particular, it has been considered difficult to construct a side-by-side structure in a lens unit of a type in which a cam ring is disposed inside a fixed barrel. However, it can be realized by adopting the structure of this embodiment. is there.

  According to the present embodiment, the elastic member as the back support means is arranged (inserted) further inside the inner cam ring and at both ends (in the lens optical axis direction) of the cam ring, so that the lens barrel Larger size can be avoided. That is, the cam follower of the moving group is not disposed inside the inner cam ring and at both ends of the cam ring, and becomes a dead space (excess space). For this reason, an increase in the size of the lens barrel can be avoided by disposing an elastic member (biasing member) as a biasing means in this dead space.

(Modification)
As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

(Modification 1)
In the above-described embodiment, the cam member has a side-by-side structure provided with extending portions at both ends in the optical axis direction of the cam member. However, the present invention is not limited to this, and the cam member has an optical axis direction in the optical axis direction. The present invention can also be applied to a structure having the above-described offset structure at only one end.

(Modification 2)
In the embodiment described above, the first extending portion 11a of the fixed barrel 11 as the first fixed housing is provided at one end in the optical axis direction of the cam member, and the second fixed housing is provided at the other end. The second extending portion 18a in the first group auxiliary frame 18 as a body was provided. However, the present invention is not limited to the case where the fixed housing and the extending portion thereof are different at both ends as described above, and the case where the fixed housing and the extending portion are the same at both ends in the optical axis direction of the cam member. The same applies to the above.

(Modification 3)
In the above-described embodiments, the projector apparatus has been described as an optical apparatus. However, the present invention is not limited to this, and can be applied to, for example, a single-lens reflex camera, a single-lens reflex electronic camera, a digital camera, and a video camera as a photographing apparatus. .

7 ·· 2 group frame, 8 ·· 3 group frame, 9 ·· 4 group frame, 10 ·· 5 group frame, 11 ·· Fixed barrel, 11a ·· Extension part, 12 ·· Cam ring, 17 ·· One-sided spring, 18 ·· 1 group auxiliary frame, 18a ·· Extension part

Claims (15)

A lens frame that holds the lens group;
A fixed housing for holding the lens frame;
A cam member that is disposed inside the fixed housing and controls the lens frame to advance and retreat in the optical axis direction;
Have
The fixed housing has an extending portion extending to the inside of the cam member,
A lens barrel characterized in that an urging member for urging the cam member toward the fixed housing is provided between the extending portion and the cam member.   The lens barrel according to claim 1, wherein the extending portion and the urging member are provided at both ends of the cam member in the optical axis direction.   The lens barrel according to claim 1, wherein the urging member is provided in two angular directions around the optical axis. The urging member is provided in two angular directions around the optical axis, and the direction of being biased by the urging member is viewed from the optical axis direction at both ends of the cam member in the optical axis direction. 3. The lens barrel according to claim 2 , wherein the lens barrels coincide with each other.   The lens barrel according to any one of claims 1 to 4, wherein the fixed casing has an opening for inserting the biasing member.   6. The lens barrel according to claim 5, wherein the opening is provided in each of three angular directions around the optical axis, and the biasing member is provided in two of the angular directions.   The lens barrel according to claim 5 or 6, wherein a length of the opening in the optical axis direction is longer than a length of the urging member in the optical axis direction. The fixed housing includes a rectilinear groove in the optical axis direction; the cam member includes a cam groove intersecting the optical axis direction; and the engaging member engaged with the rectilinear groove and the cam groove;
A holding member for holding the lens frame and holding the engaging member;
The lens barrel according to claim 1, comprising: A first lens frame holding a first lens group;
A second lens frame that holds the second lens group;
A first fixed housing for holding the first lens frame;
A second fixed housing for holding the second lens frame;
A cam member disposed inside the first and second fixed housings and configured to control the lens group to advance and retract in the optical axis direction;
Have
The first fixed housing has a first extending portion extending to the inside of the cam member at one end portion in the optical axis direction of the cam member,
The second fixed housing has a second extending portion extending to the inside of the cam member at the other end in the optical axis direction of the cam member,
A first urging member for urging the cam member toward the first fixed housing is provided between the first extending portion and the cam member;
A lens barrel characterized in that a second urging member for urging the cam member toward the second fixed housing is provided between the second extending portion and the cam member.   The lens barrel according to claim 9, wherein the first and second urging members are provided in two angular directions around the optical axis.   The direction in which the first and second biasing members are provided in the two angular directions respectively coincide with each other when viewed from the optical axis direction at both ends of the cam member in the optical axis direction. The lens barrel according to claim 10.   12. The lens mirror according to claim 9, wherein the first and second fixing housings each have an opening for inserting the first and second urging members. Tube.   The opening is provided in each of three angular directions around the optical axis, and the first and second biasing members are provided in two of the angular directions. Lens barrel.   14. The lens barrel according to claim 12, wherein a length of the opening in the optical axis direction is longer than a length of each of the first and second urging members in the optical axis direction.   An optical apparatus comprising the lens barrel according to claim 1.