JP2011002575A - Lens device and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve high magnification without an increase in size.SOLUTION: A two-group lens device 100 includes a front group 108 of negative refractive power, a diaphragm device 109 and a back group 110 having positive refractive power, these being sequentially arranged in this order from the object side. The back group 110 is moved on an optical axis from the wide-angle end to the object side, and the front group 108 is moved on the optical axis to the image side to perform variable magnification. The diaphragm device 109 is located at a fixed position from an image surface in a first range from the wide-angle end to a first intermediate focal distance state, and the diaphragm device 109 is moved on the optical axis to the image side integratively with the front group 108 in a second range from the first intermediate focal distance state to a second intermediate focal distance state, and then the diaphragm device 109 is moved on the optical axis, up to the fixed position to the object side, integratively with the front group 108, and the diaphragm device 109 is moved on the optical axis to the object side integratively with the back group 110 in a third range from the second intermediate focal distance state to the telephoto end.

Description

  The present invention relates to a two-group lens device in which a front group, a diaphragm device, and a rear group are arranged in order from the object side, and an imaging apparatus including the lens device.

  The zoom lens can freely change the focal length within a certain range without changing the focus position (with less change). Such a zoom lens is widely used, for example, when devising framing of a subject. Some zoom lenses that can freely change the focal length in this way are so-called varifocal lenses in which the focus position changes as the focal length changes.

  Conventionally, for example, it is constituted by a front group having negative refractive power as a whole, an aperture stop, and a rear group having positive refractive power as a whole, and changes the distance between the front group and the rear group in the optical axis direction. Many so-called two-group zoom lenses have been proposed in which the focal length is changed accordingly.

  In such a two-group zoom lens, in general, from the wide end, the rear group is moved to the objective side on the optical axis, and the front group is moved to the image side (eyepiece side) on the optical axis. I'm doing it.

  Specifically, there has been a technology that can provide a small, lightweight, and low-cost zoom lens that has a high optical performance of about 3 times with a simple configuration of two groups of zoom lenses and that has good optical performance. For example, see the following Patent Document 1.)

  Specifically, it is a conventional two-group zoom type zoom lens including a negative first lens group G1 and a positive second lens group G2 in order from the object side, for example. There is a technique that is fixed in the optical axis direction (see, for example, Patent Document 2 below).

JP-A-4-242709 JP 2004-221913 A

  Among the above-described conventional techniques, the technique described in Patent Document 1 is an effective technique for a zoom lens assumed to have a zoom magnification of about 3 times, and the technique described in Patent Document 2 has a zoom magnification of 4 times. This is an effective technique for a zoom lens that is assumed to be approximately, and when these techniques are used to achieve higher magnification (for example, about 5 times), it is necessary to increase the refractive power of each group.

  However, since aberration correction becomes difficult due to the increase in refractive power, aberration correction means is required. Specifically, for example, it is necessary to increase the number of lenses constituting each group or increase special optical elements such as aspherical lenses. For this reason, the above-described conventional technique has a problem that the total length of the optical system becomes long and lacks compactness. That is, the conventional techniques including the above-described Patent Documents 1 and 2 have a problem that it is difficult to realize high magnification without increasing the size of the optical system, such as increasing the optical path length or increasing the overall length. .

  SUMMARY OF THE INVENTION An object of the present invention is to provide a lens apparatus and an imaging apparatus capable of realizing a high magnification without increasing the size in order to solve the above-described problems caused by the prior art.

  In order to solve the above-described problems and achieve the object, a lens apparatus according to the present invention includes a front group having a negative refractive power, a diaphragm device that forms a diaphragm aperture, and a rear group having a positive refractive power. The two groups of lens devices are configured such that the front group, the diaphragm device, and the rear group are arranged in order from the object side, and the rear group is moved on the optical axis from the wide end toward the object side. In addition, zooming is performed by moving the front group to the image side on the optical axis, and the diaphragm device is positioned at a fixed position from the image plane in a first range from the wide end to the first intermediate focal length state. In the second range from the first intermediate focal length state to the second intermediate focal length state on the telephoto end side with respect to the first intermediate focal length, the aperture device is integrated with the front group as an optical axis. After moving the top to the image side, The aperture device is moved to the object side on the optical axis integrally with the front group to the position, and the diaphragm device is moved to the rear group within a third range from the second intermediate focal length state to the tele end. It is characterized by being configured to move integrally on the optical axis to the object side.

  In the lens device according to the present invention, in the above invention, the second range is a range in which the lateral magnification of the rear group with respect to the image position of the front group is -1 and the vicinity thereof. The range is a range larger than the lateral magnification defined by the second range, and the third range is a range smaller than the lateral magnification defined by the second range. And

  In the lens device according to the present invention, in the above invention, when the diaphragm device moves on the optical axis integrally with one of the front group or the rear group, the other of the front group or the rear group. Is capable of moving to a position overlapping with the moving range in the optical axis direction by zooming operation.

  The image pickup apparatus according to the present invention is characterized in that, in the above-described invention, a first elastic member that is supported so as to be elastically deformable in the optical axis direction and generates a first urging force toward the image side by elastic deformation; And a second elastic member that is supported so as to be elastically deformable and generates a second urging force toward the object side by elastic deformation, wherein the diaphragm device includes the first elastic member and the first elastic member in the optical axis direction. The second elastic member is supported by the first elastic member and the second elastic member in a state of receiving substantially the same first urging force and the second urging force. And

According to another aspect of the present invention, there is provided an image pickup apparatus comprising the above-described lens device and an image pickup element on which light that has passed through the lens device is incident.

  According to the above invention, the position of the diaphragm device between the front group and the rear group can be moved on the optical axis according to the positions of the front group and the rear group in the optical axis direction. This makes it possible to perform zooming by effectively using the space between the front group and the rear group.

  According to the lens apparatus and the imaging apparatus according to the present invention, the magnification can be changed by effectively using the space between the front group and the rear group. There is an effect that higher magnification can be realized.

It is explanatory drawing which shows the structure of the lens apparatus of Embodiment 1 concerning this invention. It is explanatory drawing which shows the operation state of the lens group at the time of zooming of the lens apparatus of Embodiment 1 concerning this invention, and an aperture_diaphragm | restriction. It is explanatory drawing (the 1) which shows the operation state of the lens apparatus of Embodiment 1 concerning this invention. It is explanatory drawing (the 2) which shows the operation state of the lens apparatus of Embodiment 1 concerning this invention. It is explanatory drawing which shows the general structure of the conventional 2 group type lens apparatus. It is explanatory drawing (the 1) which shows the structure of the lens apparatus of Embodiment 2 concerning this invention. It is explanatory drawing (the 2) which shows the structure of the lens apparatus of Embodiment 2 concerning this invention. It is explanatory drawing (the 1) which shows the operation state of the lens apparatus of Embodiment 2 concerning this invention. It is explanatory drawing (the 2) which shows the operation state of the lens apparatus of Embodiment 2 concerning this invention.

  Exemplary embodiments of a lens apparatus and an imaging apparatus according to the present invention are explained in detail below with reference to the accompanying drawings.

(Embodiment 1)
First, the configuration of the lens apparatus according to the first embodiment of the present invention will be described. FIG. 1 is an explanatory diagram showing the configuration of the lens apparatus according to the first embodiment of the present invention. FIG. 1 shows a cross section of the lens apparatus according to the first embodiment of the present invention, cut along a plane passing through the optical axis and parallel to the optical axis.

  In FIG. 1, a lens apparatus 100 according to the first embodiment of the present invention is fixed to, for example, an imaging apparatus main body (not shown) and constitutes an imaging apparatus together with the imaging apparatus main body. This imaging apparatus includes an imaging element (not shown) on which external light that has passed through the lens apparatus 100 enters. The imaging element is provided so that the light receiving surface, that is, the image surface is located at a position (position 101 in FIG. 1) where external light incident through the lens device 100 forms an image.

  Specifically, the imaging device can be realized by a solid-state imaging device such as a CCD image sensor (Charge Coupled Device Image Sensor) or a CMOS image sensor (Complementary Metal Oxide Semiconductor Image Sensor).

  The lens apparatus 100 includes a main lens barrel 102 and a rear lens barrel 103. Both the main barrel 102 and the rear barrel 103 have a substantially cylindrical shape and are connected in the optical axis direction. In the lens apparatus 100 according to the first embodiment, the main barrel 102 is provided on the objective side with respect to the rear barrel 103, and the rear barrel 103 is provided on the eyepiece side with respect to the main barrel 102.

  A focus operation ring 104 is provided on the outer peripheral side of the main barrel 102. The focus operation ring 104 is provided so as to be rotatable relative to the main barrel 102 around the optical axis of the main barrel 102, that is, the optical axis of the lens device 100. The rear barrel 103 is provided with a mount 105.

  The mount 105 is fixed to, for example, the imaging apparatus main body. A zooming operation ring 106 is provided on the outer peripheral side of the rear barrel 103. The zooming operation ring 106 is provided so as to be rotatable relative to the rear barrel 103 around the optical axis of the rear barrel 103, that is, the optical axis of the lens device 100.

  An aperture operation ring 107 is provided between the main barrel 102 and the rear barrel 103 in the optical axis direction and on the outer peripheral side of the main barrel 102 and the rear barrel 103. The aperture operation ring 107 is provided so as to be rotatable relative to the main lens barrel 102 and the rear lens barrel 103 around the optical axis of the main lens barrel 102 and the rear lens barrel 103, that is, the optical axis of the lens device 100. ing.

  A front group 108, an aperture device 109, and a rear group 110 are provided on the inner peripheral side of the main lens barrel 102 and the rear lens barrel 103. That is, the lens apparatus 100 according to the first embodiment is realized by a two-group zoom lens including two groups of the front group 108 and the rear group 110. The front group 108, the diaphragm 109, and the rear group 110 are arranged in the order of the front group 108, the diaphragm 109, and the rear group 110 from the objective side to the eyepiece side in the optical axis direction.

  The front group 108 is provided inside the main barrel 102 so as to be able to reciprocate in the optical axis direction. The configuration that enables the front group 108 to reciprocate in the optical axis direction inside the main barrel 102 can be easily realized by using various known techniques, and thus description thereof is omitted. The front group 108 includes a guide portion (reference numeral is omitted) facing the inner peripheral surface of the main barrel 102. This guide portion has a longitudinal shape whose longitudinal direction is the optical axis direction, and prevents the front group 108 moving on the optical axis from being inclined with respect to the optical axis.

  The rear group 110 is provided inside the rear barrel 103 so as to be able to reciprocate in the optical axis direction. The configuration that enables the rear group 110 to reciprocate in the optical axis direction inside the rear barrel 103 can be easily realized by using various known techniques, and thus the description thereof is omitted. The rear group 110 includes a guide portion (reference numeral is omitted) facing the inner peripheral surface of the rear barrel 103. This guide portion has a longitudinal shape whose longitudinal direction is the optical axis direction, and prevents the rear group 110 moving on the optical axis from being inclined with respect to the optical axis.

  FIG. 2 is a diagram illustrating the operating state of the aperture supported by the front group 108, the rear group 110, and the aperture device 109 during zooming from the wide end to the tele end of the lens apparatus according to the first embodiment of the present invention. FIG.

  In FIG. 2, the lens apparatus 100 moves the rear group 110 from the wide end position to the object side on the optical axis, and moves the front group 108 to the image plane side (eyepiece side) of the front group 108 on the optical axis. To change the magnification. When the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is larger than −1, the front group 108 is moved to the image plane side on the optical axis, and the rear group 110 is moved to the object side to change the magnification. Do it.

  In the lens apparatus 100, the diaphragm device 109 is provided so as to be movable in the optical axis direction. The aperture device 109 in the lens device 100 is positioned at a certain position from the image plane when the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is larger than −1 from the wide end position. That is, the aperture device 109 is located at a certain distance from the image plane that is the incident surface of the external light to the image sensor in the range where the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is larger than −1 from the wide end position. Is arranged. In this embodiment, the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is larger than −1 from the wide end, and the diaphragm device 109 is disposed at a position spaced apart from the image plane by a certain distance. Let the zoom range be the first range.

  Further, when the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is in the vicinity of −1, the diaphragm device 109 in the lens apparatus 100 is integrated with the front group 108 and moved to the image plane side along the optical axis. The aperture device 109 is integrated with the front group 108 and moves on the optical axis to a position separated from the image plane by a certain distance (initial position), and the rear group 110 moves on the optical axis to the object side. To do. In this embodiment, it is a range on the telephoto side relative to the first range, the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is in the vicinity of −1, and the aperture device 109 is in the front group 108. A zoom range that moves on the optical axis as a unit is taken as a second range. In this embodiment, the first range and the second range are the boundaries, and the diaphragm 109 can be moved on the optical axis by the front group 108 in a state where the diaphragm device 109 is disposed at a certain distance from the image plane. The boundary position with the correct state is defined as a first intermediate focal length.

  Further, the diaphragm device 109 in the lens apparatus 100 is integrated with the rear group 110 on the optical axis when the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is smaller than −1 (near the tele end). And the front group 108 moves on the optical axis to the object side. That is, after the diaphragm device 109 moves on the optical axis integrally with the front group 108 in the second range and is disposed again at a position (initial position) that is separated from the image plane by a certain distance, the front group 108. In a range where the lateral magnification of the rear group 110 with respect to the image position is smaller than −1 (near the tele end), the diaphragm 109 is integrated with the rear group 110 together with the front group 108 and separated to the tele end position on the optical axis. Is moved to the object side. Alternatively, after the diaphragm device 109 is separated from the front group 108 and positioned at a certain distance from the image plane for a while, the diaphragm device 109 is integrated with the rear group 110 to move the object side on the optical axis to the tele end position. The front group 108 moves to the object side on the optical axis. In this embodiment, the range from the second range to the telephoto end on the telephoto side is a range in which the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is smaller than −1, and the diaphragm 109 A zoom range including a range in which the lens unit moves together with the rear group 110 on the optical axis is defined as a third range. In this embodiment, the second range and the third range are the boundaries, and the boundary position between the state in which the diaphragm 109 can move on the optical axis by the front group 108 and the state separated from the front group 108 Is the second intermediate focal length.

  An elastic member 111 is provided on the object side of the aperture device 109 in the optical axis direction. An elastic member 112 is provided on the image plane side of the diaphragm device 109. Thereby, the aperture device 109 is held by the elastic members 111 and 112 from the object side and the image plane side. Accordingly, in the range where the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is larger than −1 from the wide end position, the diaphragm device 109 can be disposed at a position spaced apart from the image plane by a certain distance.

  Specifically, the elastic members 111 and 112 can be realized by, for example, a compression spring. The elastic member 111 applies an urging force to the diaphragm device 109 to urge the diaphragm device 109 from the object side toward the image plane side. The elastic member 112 applies a biasing force that biases the diaphragm 109 to the objective side from the image plane side.

  3 and 4 are explanatory diagrams showing the operating state of the lens apparatus 100 according to the first embodiment of the present invention. 3 and 4, the lens device 100 according to the first embodiment of the present invention is cut along a plane passing through the optical axis and parallel to the optical axis, and further cutting along a plane passing through the optical axis and orthogonal to the plane. A cross section is shown.

  FIG. 3 shows a state in which the front group 108 moves to the image plane side and is integrated with the diaphragm device 109, and the diaphragm device 109 moves to the image plane side. In FIG. 3, when the front group 108 moves to the image plane side and hits the diaphragm device 109, the front group 108 is integrated with the diaphragm device 109. Since the elastic member 112 is provided on the image plane side with respect to the diaphragm device 109, the diaphragm device 109 can move to the image plane side until the elastic member 112 is completely contracted. . Therefore, the front group 108 that has hit the diaphragm 109 can be moved further to the image plane side while pushing the diaphragm 109.

  When the front group 108 moves back to the object side from a state where the front group 108 moves toward the image plane while contracting the elastic member 112 after the front group 108 hits the diaphragm device 109, the diaphragm device 109 is moved to the elastic body. By the action of 111, it moves to the objective side in a state integrated with the front group 108. The aperture device 109 can move to the objective side up to a position separated from the image plane by a certain distance, that is, the original position (initial position). That is, the aperture device 109 moves to the image plane side so as to be pushed by the front group 108, and moves to the original position as the front group 108 pushing the aperture device 109 to the image plane side moves to the objective side. Move back to the object side.

  FIG. 4 shows a state in which the rear group 110 moves to the object side and is integrated with the diaphragm device 109, and the diaphragm device 109 moves to the object side. In FIG. 4, when the rear group 110 moves to the object side and hits the diaphragm device 109, the rear group 110 is integrated with the diaphragm device 109. Since the elastic member 111 is provided on the object side of the aperture device 109, the aperture device 109 can move to the object side until the elastic member 111 is completely contracted. For this reason, the rear group 110 that hits the diaphragm 109 can be moved further to the object side while pushing the diaphragm 109.

  When the rear group 110 moves back to the image plane side from the state where it moves to the object side while contracting the elastic member 111 after the rear group 110 hits the diaphragm device 109, the diaphragm device 109 moves to the elastic member. By the action of 111, it moves to the image plane side in a state integrated with the rear group 110. The aperture device 109 can move to the image plane side up to a position separated from the image plane by a certain distance, that is, the original position (initial position). That is, the aperture device 109 moves to the object side so as to be pushed by the rear group 110, and returns to the original position with the movement of the rear group 110 pushing the aperture device 109 to the object side toward the image plane side. Thus, it moves to the image plane side.

  FIG. 5 is an explanatory diagram showing a general configuration of a conventional two-group type lens device. In FIG. 5, the conventional two-group type lens device 400 does not include the elastic members 111 and 112 and the position of the diaphragm device 109 in the optical axis direction is fixed as compared with the lens device 100 described above. .

  In the conventional two-group zoom type lens device 400, the position of the diaphragm device 109 is fixed at a certain position from the image plane, and therefore the position of the rear group 110 at the telephoto end is limited by the position of the diaphragm device 109. . For this reason, in the conventional two-group type lens device 400, it has been difficult to achieve high magnification without changing (lengthening) the optical path length of the lens device.

  On the other hand, in the lens apparatus 100 according to this embodiment, when the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is in the vicinity of −1, the position of the diaphragm 109 is arranged at a position close to the front group 108. it can. That is, in the lens device 100 of the first embodiment, when the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is in the range of −1, the diaphragm device 109 is integrated with the front group 108 on the optical axis. Can be moved to the image plane side.

  Further, in the lens device 100 of this embodiment, the position of the diaphragm device 109 is close to the rear group 110 when the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is smaller than −1 (at the tele end). Can be placed. In other words, in the lens apparatus 100 of the first embodiment, when the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is in a range smaller than −1, the aperture device 109 is integrated with the rear group 110 and the optical axis. It is configured to be able to move up to the object side.

  For this reason, the amount of movement of the front group 108 and the rear group 110 in the optical axis direction can be increased, and further higher magnification can be realized while maintaining the same size (full length) as the conventional lens device 100. As a result, the lens apparatus 100 of this embodiment can achieve high magnification without increasing the size of the optical system. Specifically, according to the lens device 100 of the first embodiment, it is possible to provide a varifocal lens of about 5 times with a two-group zoom type.

  Further, in the conventional lens device 100, the rear group 110 is too close to the position of the diaphragm 109, and the entrance pupil position at the wide end is far from the front group 108 (particularly, the most object side lens in the front group 108). End up. In this case, the adverse effect of increasing the front lens diameter (the size of the front group 108) is assumed. Conversely, in the state where the front group 108 is too close to the position of the aperture device 109, there is a possibility that the size of the rear group 110 (the diameter of the lens constituting the rear group 110) increases.

  On the other hand, in the lens apparatus 100 according to the first embodiment, at the wide end, the position of the diaphragm device 109 is disposed at an appropriate position with respect to the front group 108 and the rear group 110 in terms of aberration correction, and Since the aperture device 109 moves integrally with the rear group 110 in the vicinity of the lateral magnification −1 of the rear group 110, it is possible to realize a high magnification while suppressing an increase in size of the front group 108 and the rear group 110. it can. As a result, a high magnification can be realized without increasing the size of the optical system.

  The lens apparatus 100 according to the first embodiment includes, in order from the object side, two groups of a front group 108 having a negative refractive power as a whole, a diaphragm device 109, and a rear group 110 having a positive refractive power as a whole. The rear group 110 is moved from the wide end position to the object side on the optical axis, and the front group 108 is moved to the image side on the optical axis to perform zooming, and the rear group with respect to the image position of the front group 108 is configured. When the lateral magnification of 110 is larger than −1, the diaphragm 109 is located at a fixed position from the image plane, and when the lateral magnification of the rear group 110 with respect to the image position of the front group 108 is around −1, the front group 108 and the diaphragm 109. Are moved together on the optical axis to the image side, and then the diaphragm 109 is moved to the object side integrally with the front group 108 to the object side to a certain position, and the image position of the front group 108 is Within the range where the lateral magnification of the rear group 110 is smaller than -1. And the throttle device 109 Oite rear group 110 is a point that is configured to move to the object side along the optical axis come together.

Specifically, the point is that the lens apparatus 100 of the first embodiment is configured to realize the following expressions (1) and (2).
WMb> -1 (1)
TMb <-1 (2)
WMb: Lateral magnification of the rear group with respect to the position of the front group image in the first range (wide end)
TMb: Lateral magnification of the rear group with respect to the front group image position in the third range (tele end)

  In the lens apparatus 100 described above, the case of using the manual diaphragm type diaphragm apparatus 109 is illustrated, but the diaphragm apparatus is not limited to the manual diaphragm type. For example, instead of a manual diaphragm type diaphragm apparatus, a DC iris type diaphragm apparatus may be used.

  As described above, according to the lens apparatus 100 of the first embodiment of the present invention, the diaphragm between the front group 108 and the rear group 110 according to the positions of the front group 108 and the rear group 110 in the optical axis direction. The position of the device 109 can be moved on the optical axis. Thereby, it is possible to perform zooming by effectively using the space between the front group 108 and the rear group 110. In addition, since the space between the front group 108 and the rear group 110 can be effectively used to perform zooming, higher magnification can be realized without increasing the size compared to the conventional lens device 100. Can do.

  In addition, according to the imaging apparatus including the lens apparatus 100 according to the first embodiment of the present invention, higher magnification can be realized without increasing the size as compared with the case where the conventional lens apparatus 100 is used. An imaging device that can be provided can be provided.

(Embodiment 2)
Next, the configuration of the lens apparatus according to Embodiment 2 of the present invention will be described. In the second embodiment according to the present invention, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  6 and 7 are explanatory views showing the configuration of the lens apparatus according to Embodiment 2 of the present invention. FIG. 6 shows a cross section of the lens apparatus according to the second embodiment of the present invention, cut along a plane passing through the optical axis and parallel to the optical axis. FIG. 7 shows an enlarged part of the lens device according to the second embodiment of the present invention. 6 and 7, a lens apparatus 500 according to the second embodiment of the present invention is fixed to, for example, an imaging apparatus main body (not shown) and constitutes an imaging apparatus together with the imaging apparatus main body.

  The aperture device 109 includes a protrusion 602 that can contact a cam surface 601 provided on the focus operation ring 104. The protrusion 602 hits a cam surface 601 provided on the focus operation ring 104 immediately before the front group 108 that moves in a direction approaching the aperture device 109 when the focus operation ring 104 is operated contacts the aperture device 109. After the projection 602 hits the cam surface 601 provided on the focus operation ring 104, the front group 108 and the diaphragm device 109 move integrally to the image plane side. The aperture device 109 that moves integrally with the front group 108 is movable within a range that does not interfere with the rear group 110.

  Further, the aperture device 109 includes a protrusion 604 that can contact a cam surface 603 provided on the variable magnification operation ring 106. The protrusion 604 is a cam surface 603 provided on the magnification change operation ring 106 immediately before the rear group 110 that moves in the direction approaching the expansion device 109 when the magnification change operation ring 106 is operated contacts the expansion device 109. It hits. After the projection 604 hits the cam surface 603 provided on the zooming operation ring 106, the rear group 110 and the aperture device 109 move integrally to the object side. The aperture device 109 that moves integrally with the rear group 110 is movable within a range that does not interfere with the front group 108.

  8 and 9 are explanatory diagrams showing the operating state of the lens apparatus 500 according to the second embodiment of the present invention. 8 and 9, the lens device 500 according to the second embodiment of the present invention is cut along a plane passing through the optical axis and parallel to the optical axis, and further cutting along a plane passing through the optical axis and perpendicular to the plane. A cross section is shown.

  In FIG. 8, by rotating the focus operation ring 104, the front group 108 moves to the image plane side, and an aperture integrated with the front group 108 via the cam surface 602 provided on the focus operation ring 104. The state where the apparatus 109 is moving to the image plane side is shown. In FIG. 8, by rotating the focus operation ring 104, the front group 108 moves to the image plane side via the cam surface 601 provided on the focus operation ring 104.

  When the front group 108 moves further to the image plane side, the front group 108 comes in front of the diaphragm device 109 and then comes through the cam surface 601 for moving the diaphragm device 109 provided on the focus operation ring 104 to the image plane side. The front group 108 hits the aperture device 109. After the front group 108 hits the aperture device 109, the front group 108 and the aperture device 109 are integrated, and the front group 108 that hits the aperture device 109 subsequently moves further to the image plane side while pushing the aperture device 109. It is possible to do.

  When the front group 108 moves back to the object side from the state where the front group 108 moves to the image plane side while contracting the elastic member 112 after hitting the diaphragm device 109, the diaphragm device 109 moves to the elastic member. By the action of 112, it moves to the object side in a state integrated with the front group 108. The aperture device 109 can move to the objective side to a position separated from the image plane side by a certain distance, that is, to the original position (initial position). That is, the aperture device 109 moves to the image plane side so as to be pushed by the front group 108, and returns to the original position as the front group 108 pushing the aperture device 109 to the image plane side moves to the object side. Move back to the object side.

  In FIG. 9, by rotating the zoom operation ring 106, the rear group 110 moves to the object side, and is integrated with the aperture device 109 via the cam surface 603 provided on the zoom operation ring 106. The state where the apparatus 109 is moving to the object side is shown. In FIG. 9, by rotating the zoom operation ring 106, the rear group 110 moves to the object side via the cam surface 603 provided on the zoom operation ring 106.

  When the rear group 110 further moves to the object side, the rear group passes through the cam surface 603 for moving the aperture device 109 provided on the magnification change operation ring 106 to the object side before the rear group hits the aperture device 109. Group 110 hits aperture device 109. After the rear group 110 hits the aperture device 109, the rear group 110 and the aperture device 109 are integrated, and the rear group 110 that hits the aperture device 109 subsequently moves further to the object side while pushing the aperture device 109. It is possible.

  When the rear group 110 moves back to the image plane side from the state where it moves to the object side while contracting the elastic member 111 after the rear group 110 hits the diaphragm device 109, the diaphragm device 109 moves to the elastic member. By the action of 111, it moves to the image plane side in a state integrated with the rear group 110. The aperture device 109 can move to the image plane side up to a position separated from the image plane by a certain distance, that is, the original position (initial position). That is, the aperture device 109 moves to the object side so as to be pushed by the rear group 110, and returns to the original position with the movement of the rear group 110 pushing the aperture device 109 to the object side toward the image plane side. Thus, it moves to the image plane side.

  As described above, according to the lens apparatus 500 of the second embodiment of the present invention, it is possible to shorten the range in which the movement range of the front group 108 and the rear group 110 does not overlap on the optical axis. As a result, a large amount of movement in the optical axis direction of the front group 108 and the rear group 110 can be ensured, so that further higher magnification can be realized while maintaining the same size (full length) as the conventional lens device 500. it can.

  In addition, according to the lens device 500 of the second embodiment, it is possible to achieve a high magnification while suppressing an increase in size of the front group 108 and the rear group 110, and thus a high magnification without increasing the size of the optical system. Can be realized. Furthermore, according to the imaging apparatus including the lens apparatus 500 according to the second embodiment of the present invention, higher magnification can be realized without increasing the size as compared with the case where the conventional lens apparatus 500 is used. An imaging device that can be provided can be provided.

  As described above, the lens device and the imaging device according to the present invention are useful for a zoom lens, and in particular, a two-group lens device in which a front group, a diaphragm device, and a rear group are arranged in order from the object side. And it is suitable for an imaging device provided with the lens device.

DESCRIPTION OF SYMBOLS 100 Lens apparatus 108 Front group 109 Aperture apparatus 110 Rear group 111,112 Elastic member 500 Lens apparatus 601 Cam surface 602 Protrusion 603 Cam surface 604 Protrusion

Claims (5)

A front group having a negative refractive power, a diaphragm device that forms a diaphragm aperture, and a rear group having a positive refractive power, wherein the front group, the diaphragm device, and the rear group are arranged in order from the object side. A two-group lens device configured,
From the wide end, moving the rear group on the optical axis to the object side and moving the front group on the optical axis to the image side,
In the first range from the wide end to the first intermediate focal length state, the diaphragm device is positioned at a certain position from the image plane,
In the second range from the first intermediate focal length state to the second intermediate focal length state on the telephoto end side from the first intermediate focal length state, the diaphragm device is integrated with the front group on the optical axis. And moving the diaphragm device to the object side on the optical axis integrally with the front group up to the position,
A lens apparatus configured to move the diaphragm device integrally with the rear group to the object side within a third range corresponding to the second intermediate focal length state to the telephoto end. . The second range is a range in which the lateral magnification of the rear group with respect to the image position of the front group is -1 and the vicinity thereof,
The first range is a range larger than the lateral magnification defined by the second range,
The lens apparatus according to claim 1, wherein the third range is a range smaller than the lateral magnification defined by the second range.   When the diaphragm device moves on the optical axis integrally with one of the front group or the rear group, the other of the front group or the rear group reaches a position where it overlaps the movement range in the optical axis direction due to zooming operation. The lens apparatus according to claim 1, wherein the lens apparatus is movable. A first elastic member supported so as to be elastically deformable in the optical axis direction and generating a first urging force toward the image side by elastic deformation;
A second elastic member supported so as to be elastically deformable in the optical axis direction and generating a second urging force toward the object side by elastic deformation,
In the optical axis direction, the diaphragm device includes the first elastic member and the second elastic member between the first elastic member and the second elastic member. The lens device according to claim 1, wherein the lens device is supported in a state of receiving a force and the second urging force. The lens device according to any one of claims 1 to 4,
An image sensor on which light having passed through the lens device is incident;
An imaging apparatus comprising:

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