JP7703353B2 - Lens barrel, lens device and imaging device - Google Patents

Description

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

Some broadcast lens devices have an autofocus function that uses a phase difference detection method. Patent Document 1 discloses a lens device that includes a spectroscopic prism and a phase difference detection sensor and has an autofocus function. The light beam that passes through the spectroscopic prism is incident on the imaging element in the camera, and the light beam reflected by the spectroscopic prism is incident on the phase difference detection sensor.

The position of the phase difference detection sensor in the optical axis direction can be adjusted by changing the thickness of a washer member attached to the member to be adjusted. In addition, in Patent Documents 2 and 3, an eccentric pin is used to adjust the position of the lens in the optical axis direction in a space-saving manner.

Patent No. 4850692 Japanese Unexamined Patent Publication No. 63-237012 Patent No. 3424217

In the structure disclosed in Patent Document 2, the lens can move due to play between the eccentric pin and the cylinder. In addition, in the structure disclosed in Patent Document 3, the lens barrel can become eccentric because the lens barrel is fixed in place by pressing it radially with a lock screw after it has been adjusted with the eccentric pin.

The present invention aims to provide, for example, a lens barrel that is advantageous for positioning optical elements.

In order to achieve the above-mentioned object, the lens barrel of the present invention comprises a housing, a holding member that holds an optical element, a first pressing member that brings a first contact portion of the holding member and a second contact portion of the housing into contact with each other and presses them together, a driving member that drives the holding member relative to the housing in the optical axis direction while the first contact portion and the second contact portion are brought into contact with each other and pressed by the first pressing member, and a fixing member that brings the first contact portion and the second contact portion into contact with each other, pressing them together and fixing them , and is characterized in that the first pressing member and the fixing member are separate members .

The present invention can provide, for example, a lens barrel that is advantageous for positioning optical elements.

FIG. 2 is a cross-sectional view of the imaging unit of the first embodiment. FIG. 2 is an exploded perspective view of the phase difference detection unit. FIG. 2 is a front view of the phase difference detection unit. FIG. 2 is a side view of the phase difference detection unit. FIG. 4 is a rear view of the phase difference detection unit. This is a cross-sectional view taken along line AA in FIG. This is a cross-sectional view taken along line B-B of FIG. FIG. 11 is a cross-sectional view of an imaging unit according to a second embodiment. FIG. FIG. This is a cross-sectional view taken along the line CC of FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
In addition, the drawings shown below may be drawn at a scale different from the actual scale in order to facilitate understanding of the present embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A lens barrel according to a first embodiment of the present invention, and a lens apparatus and an imaging system (imaging apparatus) having the lens barrel will be described below with reference to FIGS.
A zoom lens device (lens device) 101 and a camera device 102 (television camera, video camera, etc.) will be described with reference to FIG. 1. FIG. 1 is a cross-sectional view of an imaging system (imaging device) composed of the zoom lens device 101 and the camera device 102. The zoom lens device 101 is attached to the camera device 102 by engaging a mount unit 1 composed of the zoom lens device 101 with a supporter unit 2 composed of the camera device 102, thereby forming an imaging system. The focus lens group 3 composed of the zoom lens device 101 is movable in the optical axis direction, and changes the position of the image plane by moving in the optical axis direction by a drive unit (not shown) (i.e., performs focusing). The variable magnification lens group composed of the variable magnification lens 4 and the variable magnification lens 5 changes the focal length by moving in the optical axis direction. The light passing through these lenses is split into two light beams by a spectral prism (light splitting element) 6 arranged on the imaging optical path. One of the light beams (second light) transmitted through the spectral prism 6 passes through a relay lens 7 and enters an image sensor 9 such as a CCD sensor or a CMOS sensor mounted on a camera unit 8 of the camera device 102. The other light beam (first light) reflected by the spectral prism 6 is guided to a phase difference detection unit 103 for detecting the focus state of the focus lens group, and the focus is detected by a phase difference detection method. The phase difference detection unit 103 includes at least one of a light receiving element and a lens.

With the above configuration, the focus deviation detected by the focus detection means is used to control the drive unit via a CPU (control unit) (not shown) to change the position of the focus lens group 3, thereby realizing an autofocus function.

The phase difference detection unit 103 will be described with reference to FIGS.
Fig. 2 is an exploded perspective view of the phase difference detection unit 103. Fig. 3 is a front view of the phase difference detection unit 103, Fig. 4 is a side view, and Fig. 5 is a rear view. Fig. 6 is a cross-sectional view taken along the line AA in Fig. 3.
The housing 11 holding the lens 10 is fixed to the mirror body 13 by a fixing bolt (fixing member) 12. The holding member 15 holding the phase difference detection unit 14 is fixed to the housing 11 by a fixing bolt 16 that passes through an elongated hole in the housing 11, the elongated direction of which is the movement direction of the holding member 15. An eccentric pin (driving member) 17 having an eccentric shaft 17a that engages with the elongated groove 15a is rotatably held in the housing 11 by a metal plate 18 and a fixing screw 19. A plurality of plungers 20 (20a, 20b) including an elastic member provided on the housing 11 press the holding member 15, so that the holding member 15 is constantly pressed against and in contact with the two inner walls of the housing 11. The lid 21 is attached to the housing 11, making it possible to prevent dust from entering the housing 11.

With the above configuration, when the eccentric pin 17 is rotated with the fixing bolt 16 loosened, the holding member 15 moves along the inner wall of the housing 11 via the eccentric shaft 17a and the long groove 15a, making it possible to adjust the distance between the lens 10 and the phase difference detection unit 14. In other words, it becomes possible to adjust the focus of the phase difference detection unit 14.

Based on FIG. 7, the fixation of the phase difference detection unit 14 after adjustment will be described. FIG. 7 is a cross-sectional view taken along the line B-B of FIG. 3. The five plungers (first pressing members) 20a press the first surface (flat surface) (first contact portion) 15b of the holding member 15 against the second surface (flat surface) (second contact portion) 11a of the housing 11 to which the fixing bolt 16 is attached. On the other hand, the four plungers (second pressing members) 20b press the third surface (third contact portion) 15c of the holding member 15 against the fourth surface (fourth contact portion) 11b of the housing 11 perpendicular to the second surface 11a. In other words, the holding member 15 is pressed against the housing 11 by the plungers 20a and 20b, so that it is possible to move linearly in a direction parallel to the second surface 11a and the fourth surface 11b without any backlash. In addition, since there are more plungers 20a than plungers 20b, the force (pressure) that the first surface 15b receives from the plungers 20a is greater than the force (pressure) that the third surface 15c receives from the plungers 20b. Therefore, the first surface 15b of the holding member 15 fastened by the fixing bolt 16 is always in contact with the second surface 11a of the housing 11, so that the position of the holding member 15 does not change even if the holding member 15 is fixed to the housing 11 by tightening the fixing bolt 16. Furthermore, the holding member 15 receives a force from the plungers 20b in the direction of the fourth surface 11b so as to counter the rotational force when the fixing bolt 16 is screwed in, and the third surface 15c and the fourth surface 11b are in contact with each other, so that the holding member 15 can be prevented from tilting.

With the above configuration, even if the fixing bolt 16 is tightened after adjusting the phase difference detection unit 14, the position of the holding member 15 does not change relative to the housing 11, making it possible to fix the adjustment without degrading the optical performance.

As described above, according to this embodiment, it is possible to adjust the position of the phase difference detection unit 14 in the optical axis direction without degrading the optical performance. In addition, since the adjustment can be made by simply rotating the eccentric pin 17, there is no need to reserve space to replace the conventional washer, and a compact adjustment mechanism can be configured. Furthermore, since the only access to the parts during adjustment is through the eccentric pin 17 and the fixing bolt 16, which are arranged on the same side of the housing 11, adjustment is possible by making it accessible from one direction, and assembly workability is good.

In this embodiment, the configuration of the phase difference detection unit has been simplified and explained as a phase difference detection section 14. However, in reality, it also includes a phase difference detection lens that splits an incident light beam into two light beams, and an imaging element (a line sensor or a pixel sensor) that photoelectrically converts a pair of images formed by the two split light beams.

In this embodiment, the present invention is applied to adjusting the position of the phase difference detection unit 14. However, the present invention is not limited to this. The present invention can be applied to a wide range of spacing adjustments of optical elements (lenses, apertures, image sensors, filters, diffraction elements, reflective elements, phase difference detection units, etc.) that are arranged on the optical axis of a lens device, such as adjusting the spacing between lenses or between a lens and an image sensor.

Second Embodiment A lens barrel according to a second embodiment of the present invention, and a lens apparatus and an imaging system (imaging apparatus) having the lens barrel will be described below with reference to FIGS.
The zoom lens device 201 and the camera device 202 (television camera, video camera, etc.) will be described with reference to FIG.

Figure 8 is a cross-sectional view of an imaging system (imaging device) composed of a zoom lens device 201 and a camera device 202. The mount section 22 of the zoom lens device 201 and the support section 23 of the camera device 202 are engaged with each other, so that the zoom lens device 201 is detachably attached to the camera device 202, thereby forming the imaging system.

The focus lens 24 configured in the zoom lens device 201 changes the position of the image plane by moving in the optical axis direction (i.e., performs focusing). The variable magnification lens 25 and the variable magnification lens 26 change the focal length by moving in the optical axis direction. Light that passes through these lenses passes through the adjustment lens unit 203 and the relay lens 27 and is incident on an image sensor 29 such as a CCD sensor or a CMOS sensor mounted on the camera section 28 of the camera device 202.

The adjustment lens unit 203 will be described with reference to FIGS.
Fig. 9 is an exploded perspective view of the adjustment lens unit 203. Fig. 10 is a cross-sectional view of the adjustment lens unit 203. Fig. 11 is a cross-sectional view taken along CC in Fig. 10.

The housing 31 holding the lens 30 is fixed to the lens body 32. The lens barrel 34 holding the lens 33 is fixed to the housing 31 so that it does not move in the axial direction due to frictional force caused by the outer circumferential surface being pressed by a set screw (fixing member) 3. The eccentric pin 36 having an eccentric shaft 36a that engages with the long groove 34a is rotatably held in the housing 31 by a metal plate 37 and a fixing screw 38. The plungers 39 (39a, 39b) including elastic members provided at two different positions (90 degrees apart in this embodiment) around the axis of the housing 31 press the lens barrel 34, so that the lens barrel 34 is always in contact with the inner wall of the housing 31.

With the above configuration, when the eccentric pin 36 is rotated from the hole 32a of the body 32 with the set screw 35 loosened, the lens barrel 34 moves in the axial direction of the lens barrel 34 (housing 31) along the inner wall of the housing 31 via the eccentric shaft 36a and the long groove 34a. This makes it possible to adjust the distance between the lens 30 and the lens 33. In other words, it becomes possible to adjust the optical performance of the zoom lens device 201.

Based on FIG. 11, the fixing of the lens barrel 34 after adjustment will be described. FIG. 11 is a cross-sectional view taken along the CC line in FIG. 10. The lens barrel 34 has a notch 34b. The plunger (first pressing member) 39a, which is arranged in the same phase as the eccentric pin 36, presses the first contact portion 34c of the lens barrel 34 against the second contact portion 31a of the housing 31. The other plunger (second pressing member) 39b presses the third contact portion 34d, which is at a position 90 degrees around the axis relative to the first contact portion 34c, against the fourth contact portion 31b of the housing 31. In other words, the lens barrel 34 is pressed against the housing 31 by the plungers 39a and 39b, so that it can move linearly without any backlash. In addition, the force applied to the lens barrel 34 by the plungers 39a and 39b is set so that the force applied to the first contact portion 34c is greater than the force applied to the third contact portion 34d. As a result, the first contact portion 34c, which is in the direction in which the lens barrel 34 is pressed by the set screw 35, is always in a contact state following the fourth contact portion 31b of the housing 31. Therefore, even when the set screw 35 is attached, the contact state of the first contact portion 34c is released and does not separate, and the position of the lens barrel 34 does not change. Furthermore, the lens barrel 34 receives a force from the plunger 39b in the direction of the fourth contact portion 31b to counter the rotational force when the set screw 35 is screwed in, and the third contact portion 34d is in contact with the fourth contact portion 31b of the housing 31, so that the lens barrel 34 can be prevented from tilting.

With the above configuration, even if the set screw 35 is tightened after adjusting the lens 33, the position of the lens barrel 34 does not change relative to the housing 31, making it possible to fix the lens after adjustment without degrading the optical performance.

As described above, according to this embodiment, it is possible to adjust the position of the lens 33 in the optical axis direction without degrading the optical performance. In addition, since the adjustment can be made by simply rotating the eccentric pin 36, there is no need to secure space to replace the conventional washer, and the system is compact. Furthermore, since the only access to the parts during adjustment is through the eccentric pin 36 and the set screw 35 from the hole 32a, adjustment can be made by accessing from one direction, and assembly workability is good.

A lens device having the lens barrel of the present invention can be realized that achieves the effects of the present invention. Also, an imaging device having a lens device having the lens barrel of the present invention and an imaging element that captures an image formed by the lens device can be realized that achieves the effects of the present invention. Although preferred examples of the present invention have been described above, the embodiments of the present invention are not limited to these examples, and various modifications and variations are possible.

In addition, in each of the above embodiments, a zoom lens device that is attached to a camera is described, but the present invention can also be applied to a lens-integrated imaging device (optical equipment).

101: Zoom lens device
103: phase difference detection unit 11: housing 11a: second surface (second contact portion)
14: Phase difference detection unit 16: Fixing bolt (fixing member)
17, 36: Eccentric pin (driving member)
15, 34: Holding member 15b: first surface (first contact portion)
34c: first contact portion (first contact portion)

Claims (14)

A housing and
A holding member for holding an optical element;
a first pressing member that brings a first contact portion of the holding member and a second contact portion of the housing into contact with each other and presses them;
a driving member that drives the holding member relative to the housing in the optical axis direction in a state in which the first contact portion and the second contact portion are brought into contact with each other and pressed against each other by the first pressing member;
a fixing member that brings the first contact portion and the second contact portion into contact with each other and presses them to fix them ,
The lens barrel according to claim 1, wherein the first pressing member and the fixing member are separate members . 2 . The lens barrel according to claim 1 , wherein the first pressing member presses the first contact portion of the holding member against the second contact portion of the housing to which the fixing member is attached. 3. The lens barrel according to claim 1, further comprising a second pressing member that brings a third contact portion of the holding member, which is different from the first contact portion, and a fourth contact portion of the housing, which is different from the second contact portion, into contact with each other and presses them against each other. 4. The lens barrel according to claim 3 , wherein the pressing force of the first pressing member is greater than the pressing force of the second pressing member. 5. The lens barrel according to claim 1, wherein the driving member is rotatably held by the housing, and has an eccentric pin that engages with a long groove formed in the holding member. 6. The lens barrel according to claim 1 , wherein the drive member and the fixed member are disposed on the same surface of the housing. 7. The lens barrel according to claim 1, wherein the first pressing member includes an elastic member. 7. The lens barrel according to claim 1, wherein the first pressing member is made up of a plurality of elastic members. 5. The lens barrel according to claim 3 , wherein the second pressing member includes an elastic member. A lens barrel according to any one of claims 1 to 9 ,
A lens device comprising: a light dividing element that divides incident light into a first light beam directed toward the optical element and a second light beam different from the first light beam. The lens apparatus according to claim 10 , wherein the optical element includes at least one of a light receiving element and a lens. A lens barrel according to any one of claims 1 to 9 ,
a lens held by the holding member;
A lens device, wherein the position of the lens is adjusted by the driving member. A focus lens group is provided.
13. The lens apparatus according to claim 10 , wherein the optical element includes a light receiving element for detecting a focus state achieved by the focus lens group. 14. An imaging device comprising: a lens device according to claim 10 ; and an imaging element for capturing an image formed by the lens device.

Images