JP6291651B2 - Lens device for optical equipment - Google Patents

Description

  The present invention relates to a lens apparatus of an optical apparatus including a focus adjustment mechanism that performs focus adjustment by displacing a predetermined lens group in the front-rear direction by operation of a focus adjustment operation unit.

  In general, a lens device of an optical apparatus includes a focus adjustment mechanism and a zooming adjustment mechanism. The focus adjustment mechanism has a function of focusing by displacing a predetermined lens group in the front-rear direction by operation of the focus adjustment operation unit. However, focus adjustment from the lens apparatus is only performed by focus adjustment by such a focus adjustment mechanism. Since the edge of the image is bent or blurred depending on the distance, it is necessary to perform finer adjustment, that is, image plane adjustment for the lens group in order to eliminate these phenomena.

  Conventionally, as a lens apparatus having a function of performing such image surface adjustment, a lens apparatus provided with a lens system control apparatus disclosed in Patent Document 1 and a zoom lens (lens apparatus) disclosed in Patent Document 2 are disclosed. Are known. The lens system control device disclosed in the document 1 is mounted on a camera or the like, and controls the position of a zoom lens and a lens for image plane correction and focus adjustment with an electronic control circuit, and in manual focus mode. The purpose is to prevent blur caused by changes in the subject distance. Specifically, when you want to zoom from one end of zooming to the other in manual focus mode, zoom from the opposite end to the other end. This is accomplished by storing the movement locus of the focus lens and tracing this movement locus in reverse, but if the focus lens moves away from the stored movement locus by a certain amount or more, the movement locus is followed thereafter. Is forbidden. The zoom lens disclosed in the document 2 is mounted on a camera or the like, and has a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a first lens having a positive refractive power from the object side. Consists of three lens groups. When zooming from the wide-angle end to the telephoto end, the second lens group moves from the object side to the image side, and the third lens group moves back and forth to correct the image plane during zooming. The objective of the present invention is to provide a compact zoom lens having a zoom ratio of about 3 times, a small distortion aberration, and a short overall lens length. The distance, the focal length of the first lens group, and the imaging magnification of the third lens group at the telephoto end satisfy a predetermined conditional expression.

Japanese Patent Laid-Open No. 5-134166 JP-A-9-236748

  However, the above-described conventional lens device (lens system control device, zoom lens) has the following problems.

  First, the image plane adjustment system is configured as an adjustment system independent of the focus adjustment system and adopts a configuration in which the lens is displaced by an electric drive system including a drive motor and a motion conversion mechanism. As the number of assembly steps increases, the overall structure becomes complicated (complex). Therefore, a significant cost increase including both the component cost and the manufacturing cost is caused, and the entire lens device is increased in size and weight.

  Second, the image plane adjustment system is constituted by an independent electric drive system, that is, an adjustment amount (correction amount) related to image plane adjustment is obtained by arithmetic processing, and a control amount related to the obtained adjustment amount is supplied to the drive motor. Then, since the lens is displaced, the time until the adjustment is completed becomes long and the response is difficult. In addition, basically, the focus adjustment and the image plane adjustment are performed independently without being synchronized with the focus adjustment system. Therefore, it cannot always be said that it is sufficient from the viewpoint of ensuring stability and smoothness.

  An object of the present invention is to provide a lens device for an optical apparatus that solves the problems existing in the background art.

  In order to solve the above-described problems, the present invention provides a focus adjustment mechanism 4 that performs focus adjustment by displacing the focus lens unit 3 in the optical axis direction Fc by operating at least the focus adjustment operation unit 2 provided in the lens barrel C. When configuring the lens apparatus 1 of the optical device P provided, the image surface is disposed so as to be displaceable in the optical axis direction Fc by screwing with the outer peripheral surface of the fixed cylinder portion Cc at the frontmost position Xf of the lens barrel C. The image plane adjustment lens unit 5 having the adjustment lens La, the intermediate cylinder Cm that is rotated by the operation of the focus adjustment operation unit 2, and the rotational displacement of the intermediate cylinder Cm are arranged behind the image plane adjustment lens unit 5. A link mechanism unit 12 for transmitting to the focus lens unit 3 and a motion conversion mechanism unit 13 for converting the rotational displacement of the focus lens unit 3 into a displacement in the optical axis direction Fc are provided. The focus adjustment mechanism 4, the link mechanism portion 14 that transmits the rotational displacement of the intermediate cylinder Cm to the image plane adjustment lens portion 5, and the rotational displacement of the image plane adjustment lens portion 5 is motion-converted into the optical axis direction Fc. And a motion conversion mechanism unit 15 for converting the image plane displacement, and the image plane adjustment lens unit 5 is displaced in the optical axis direction Fc by a displacement amount for adjusting the image plane corresponding to the operation amount of the focus adjustment operation unit 2. An image plane adjustment mechanism 6 that performs image plane adjustment, and the image plane adjustment lens unit 5 also serves as a hood of the image plane adjustment lens La, and the motion conversion mechanism unit 15 and the link mechanism unit in the image plane adjustment mechanism 6 4 is provided with a cylindrical cover 45 covering at least a part of 4.

  In this case, according to a preferred aspect of the invention, a fixed lens unit 11 having a fixed position can be disposed between the image plane adjustment lens unit 5 and the focus lens unit 3. Further, it is desirable to use a single aspherical lens Las as the image plane adjusting lens La. The optical device P can be applied to the projector Pp.

  According to the lens apparatus 1 of the optical apparatus P according to the present invention having such a configuration, the following remarkable effects can be obtained.

  (1) An image surface corresponding to the amount of operation of the image adjustment lens unit 5 having the image surface adjustment lens La disposed on the lens barrel C so as to be displaceable in the optical axis direction Fc, and the focus adjustment operation unit 2. The image plane adjustment lens unit 5 is displaced in the optical axis direction Fc by the amount of displacement to be adjusted, and the image plane adjustment mechanism 6 that performs image plane adjustment is provided. Therefore, the lens is driven by an electric drive system including a drive motor and a motion conversion mechanism. An independent image plane adjustment system such as displacement is not required, and the number of parts and the number of assembling steps can be reduced, and the overall configuration can be simplified (simplified). Therefore, it is possible to realize a significant cost reduction including both the component cost and the manufacturing cost, and to contribute to the reduction in size and weight of the entire lens apparatus 1.

  (2) Since the operation of the focus adjustment operation unit 2 is transmitted directly and directly to both the focus lens unit 3 and the image plane adjustment lens unit 5, adjustment timings for both focus adjustment and image plane adjustment are provided. Can always be synchronized. Therefore, the delay in image plane adjustment can be eliminated, the responsiveness can be improved, the speed of image plane adjustment can be increased, and an adjustment system with high stability and smoothness can be constructed.

  (3) Since the image plane adjustment lens unit 5 is screwed onto the outer peripheral surface of the fixed barrel portion Cc of the lens barrel C, the image plane adjustment lens portion 5 can be directly supported by the fixed barrel portion Cc of the lens barrel C. The mechanical strength of the adjustment system including the image plane adjustment lens unit 5 can be increased, and the image plane adjustment lens La can be supported with high accuracy and stability.

  (4) Since the image plane adjustment lens unit 5 is disposed at the frontmost position Xf of the lens barrel C, and the focus lens unit 3 is disposed at a position Xr behind the image plane adjustment lens unit 5, The focus lens unit 3 that is usually composed of a lens group including a plurality of lenses and is heavy is disposed at a rear position Xr that is separated from the foremost part of the lens barrel C, and the rear end of the lens device 1 is separated by one piece. In addition to contributing to a reduction in moment load applied to the supporting mechanism for holding and supporting, another lens, for example, a fixed lens unit 11 with a fixed position is disposed between the image plane adjustment lens unit 5 and the focus lens unit 3. For example, the functionality and diversity of the lens apparatus 1 can be enhanced.

  (5) The focus adjustment mechanism 4 includes an intermediate cylinder Cm that is rotated by the operation of the focus adjustment operation section 2, a transmission link mechanism section 12 that transmits the rotational displacement of the intermediate cylinder Cm to the focus lens section 3, and the focus lens section 3. In the embodiment of the present invention, the general-purpose focus adjustment mechanism 4 is used as it is, or a slight amount of the rotation displacement is converted into a displacement in the optical axis direction Fc. It can be used with modification, and can contribute to further reduction in size and weight and cost.

  (6) The image plane adjustment mechanism 7 includes a link mechanism unit 14 that transmits the rotational displacement of the intermediate cylinder Cm to the image plane adjustment lens unit 5, and a motion conversion of the rotational displacement of the image plane adjustment lens unit 5 to convert the optical axis. Since it is configured to include the motion conversion mechanism unit 15 that converts the displacement in the direction Fc, a part of the existing focus adjustment mechanism 4 can also be used, which can contribute to ease of implementation, further reduction in size, weight, and cost. .

  (7) According to a preferred embodiment, if one aspherical lens Las is used for the image plane adjustment lens La, the image plane adjustment lens unit 5 can be reduced in weight. Even when the lens is disposed at the foremost position Xf, a problem that the moment load applied to the support mechanism for cantilevering the rear end of the lens apparatus 1 can be avoided, and the focus adjustment operation unit 2 It is possible to avoid problems that increase the operating force.

  (8) According to a preferred embodiment, the optical device P is optimally applied to the projector Pp. That is, in the case of the projector Pp, the screen size projected onto the screen is large, and the curvature and blurring that occur in a part of the image are easily noticeable. Therefore, the projector Pp is optimally applied to the projector Pp from the viewpoint of effectively eliminating this problem. .

Sectional side view which extracts and shows the structure of the principal part of the lens apparatus which concerns on suitable embodiment of this invention, Cross-sectional side view of the lens device, Principle configuration diagram for explaining the function of the lens device, External plan view showing the entire lens device, Displacement characteristic diagram of the image plane adjustment lens with respect to the distance to the screen in the image plane adjustment mechanism of the lens device,

  Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.

  First, an overall schematic configuration of the lens apparatus 1 according to the present embodiment will be described with reference to FIGS.

  FIG. 4 shows an overall appearance configuration of the lens apparatus 1. The illustrated lens apparatus 1 is for a projector Pp (optical apparatus P), and is attached to a support mechanism inside the projector Pp by flange portions 21 and 21 provided on the outer peripheral surface Ccf of the fixed cylinder portion Cc constituting the lens barrel C. be able to. Thereby, the front end side of the lens apparatus 1 protrudes ahead from the front panel Ppf of the projector Pp. The lens device 1 according to the present invention (the present embodiment) is optimally used for such a projector Pp. That is, in the case of the projector Pp, the screen size projected on the screen is large, and the curvature and blurring generated in a part of the image are easily noticeable. Therefore, the projector Pp is optimally used for the projector Pp from the viewpoint of effectively eliminating this problem.

  Further, the focus ring 2r and the zoom ring 22 are rotatably mounted on the outer peripheral surface Ccf of the fixed cylinder portion Cc. The focus ring 2r and the zoom ring 22 have driven gears 2rg and 22g formed over the entire circumference. On the other hand, on the outer peripheral surface Ccf located on the left and right of the fixed cylinder portion Cc, the rotational drive portions 24 and 25 including the drive motor are attached, and the drive gears 24g and 25g attached to the output shafts of the rotational drive portions 24 and 25 are The driven gears 2rg and 22g are engaged with each other. The focus ring 2r constitutes the focus adjustment operation unit 2. Although the illustrated focus ring 2r is an electric system that is rotated by the rotation drive unit 24, it can also be configured by a manual system that rotates the focus ring 2r by hand.

  On the other hand, FIG. 2 shows the internal structure of the lens device 1. The lens barrel C in the lens apparatus 1 incorporates a plurality of lenses La, L1, L2,. The lenses La, L1, L2,... Constitute a lens group for each of one or more lenses. From the front, La is an image plane adjustment lens and constitutes the image plane adjustment lens unit 5, the next three lenses L1 to L3 constitute a fixed lens unit 11, and the next four lenses L4 to L7 are in focus. The lens unit 3 is configured, the next nine lenses L8 to L16 configure the zoom lens unit 26, and the next lens L17 configures the rear end lens unit 27 whose position is fixed. In FIG. 2, reference numeral 51 denotes an optical system inside the projector Pp, and light enters the rear end (rear end lens portion 27) of the lens device 1 from the optical system 51.

  Next, the configuration of the main part of the lens apparatus 1 according to the present embodiment will be specifically described with reference to FIGS.

  The lens apparatus 1 includes a focus adjustment mechanism 4 as a basic configuration. The focus adjusting mechanism 4 includes the above-described focus ring 2r, an intermediate cylinder Cm that is rotated by a rotation operation of the focus ring 2r, and a link mechanism unit that transmits the rotation displacement of the intermediate cylinder Cm to the focus lens unit 3. 12 and a motion conversion mechanism unit 13 using a helicoid screw mechanism that converts the rotational displacement of the focus lens unit 3 into a displacement in the optical axis direction Fc. In this case, the intermediate cylinder Cm is disposed such that the outer peripheral surface is in contact with the inner peripheral surface of the fixed cylinder portion Cc. Then, as shown in FIG. 1, the first transmission pin 31p having one end coupled to the vicinity of the front end of the focus ring 2r is passed through the fixed cylinder portion Cc, and the other end is coupled to the intermediate cylinder Cm. Therefore, a guide slit portion 31g through which the first transmission pin 31p passes is formed in the fixed cylinder portion Cc along the circumferential direction. Thereby, the displacement of the first transmission pin 31p in the circumferential direction is allowed. The guide slit portion 31g and the first transmission pin 31p constitute the first transmission portion 31. In the illustrated example, three first transmission portions 31 are arranged at equal intervals at three locations in the circumferential direction.

  On the other hand, the focus lens unit 3 includes a lens holding cylinder 32 that holds the four lenses L4 to L7. The focus lens unit 3 is a lens barrel that is located at a position Xr behind the image plane adjustment lens unit 5. Arranged at an intermediate position of C. Further, the outer peripheral surface of the rear portion of the lens holding cylinder 32 is screwed to the inner peripheral surface of the zoom interlocking cylinder 33 through the motion conversion mechanism 13 using a helicoid screw mechanism. The zoom interlocking cylinder 33 is displaced in the optical axis direction Fc in response to the rotation operation of the zoom ring 22. Further, a first restriction slit portion 35s that is parallel to the optical axis direction Fc is formed at a position other than the portion where the first transmission pin 31p is coupled in the intermediate cylinder Cm, and the lens is held in the first restriction slit portion 35s. The first engagement pin 35p provided at the front portion of the cylinder 32 is engaged. The first engagement pin 35p protrudes from the outer peripheral surface of the lens holding cylinder 32 in the radial direction. The first restriction slit portion 35s and the first engagement pin 35p constitute the first engagement portion 35. In the illustrated example, the three first engagement portions 35 are arranged at equal intervals at three locations in the circumferential direction. It is.

  As described above, the intermediate cylinder Cm that is rotated by the operation of the focus ring 2r, the link mechanism section 12 that transmits the rotation displacement of the intermediate cylinder Cm to the focus lens section 3, and the rotation displacement of the focus lens section 3 is converted into motion. Thus, the focus adjustment mechanism 4 including the motion conversion mechanism unit 13 that converts the displacement into the displacement in the optical axis direction Fc is configured. Therefore, when such a focus adjustment mechanism 4 is provided, the general-purpose focus adjustment mechanism 4 can be used as it is or with a slight change in implementing the present invention. There is an advantage that can contribute to the conversion.

  On the other hand, a second transmission pin 37p having one end coupled to the vicinity of the front end of the intermediate cylinder Cm is passed through the fixed cylinder Cc, and the other end is coupled to the transmission cylinder 38. Therefore, a guide slit portion 37g through which the second transmission pin 37p passes is formed in the fixed cylinder portion Cc along the circumferential direction, and displacement of the second transmission pin 37p in the circumferential direction is allowed. The guide slit portion 37g and the second transmission pin 37p constitute a second transmission portion 37. In the illustrated example, three second transmission portions 37 are arranged at equal intervals at three locations in the circumferential direction. Further, the transmission cylinder 38 has a shape in which a small-diameter cylinder part 38s that is in contact with the outer peripheral surface of the fixed cylinder part Cc and a large-diameter cylinder part 38m that is formed in a large diameter corresponding to the diameter of the fixed lens part 11 are integrally formed. The second transmission pins 37p are coupled to the small diameter cylindrical portion 38s.

  Further, as shown in FIG. 1, the image plane adjustment lens La disposed at the frontmost position Xf of the lens barrel C is held by a lens holding barrel 41. In this case, the image plane adjustment lens La is constituted by a single aspherical lens Las. When such a single aspherical lens Las is used, the image plane adjustment lens unit 5 can be reduced in weight, and therefore the image plane adjustment lens unit 5 is disposed at the position Xf that is the foremost part of the lens barrel C. Even so, it is possible to avoid the problem that the moment load applied to the support mechanism that cantilever-supports the rear end of the lens device 1 can be avoided and the problem that the operation force of the focus adjustment operation unit 2 can be avoided. is there.

  On the other hand, the three lenses L1 to L3 in the fixed lens portion 11 are fixed by the lens fixing tube 42, and the rear portion of the lens fixing tube 42 is coupled and fixed to the front end of the fixed tube portion Cc. Therefore, the lens fixing cylinder 42 substantially becomes a part of the fixing cylinder portion Cc. On the other hand, the rear inner peripheral surface of the lens holding cylinder 41 that holds the image plane adjustment lens La is screwed to the front outer peripheral surface of the lens fixing cylinder 42 via the motion conversion mechanism 15 using a helicoid screw mechanism. As a result, the image plane adjustment lens unit 5 is screwed into the fixed barrel portion Cc of the lens barrel C, so that the image plane adjustment lens portion 5 is directly supported by the fixed barrel portion Cc of the lens barrel C, and the image There are advantages that the mechanical strength of the adjustment system including the surface adjustment lens unit 5 can be increased and the image surface adjustment lens La can be supported with high accuracy and stability.

  A second engagement pin 43p protruding radially outward is fixed to the outer peripheral surface of the rear portion of the lens holding tube 41, and the large diameter tube portion 38m of the transmission tube 38 is parallel to the optical axis direction Fc. The second restriction slit 43s is formed, and the second engagement pin 43p is engaged with the second restriction slit 43s. The second restricting slit portion 43s and the second engaging pin 43p constitute the second engaging portion 43. In the illustrated example, the second engaging portions 43 are arranged at equal intervals at three locations in the circumferential direction. It is. Furthermore, a relatively large diameter cylindrical cover 45 that also serves as the hood of the image plane adjustment lens La is attached to the lens holding cylinder 41. As shown in FIG. 1, the cylindrical cover 45 is fixed to the front end of the lens holding cylinder 41, and has an overall shape so as to cover most of the large-diameter cylindrical part 38m by the rear part.

  The image plane adjustment mechanism 6 is configured by the above configuration. Therefore, the image plane adjustment lens unit 5 having the image plane adjustment lens La is disposed so as to be displaceable in the optical axis direction Fc with respect to the lens barrel C, and the image plane corresponds to the operation amount of the focus ring 2r. The pitch of the helicoid screw mechanism 34 and the optical characteristics of the image plane adjustment lens La are selected so that the image plane adjustment lens unit 5 can be displaced in the optical axis direction Fc by a displacement amount for adjusting the image plane adjustment lens La. In addition, as illustrated, the image plane adjustment mechanism 6 includes a link mechanism unit 14 that transmits the rotational displacement of the intermediate cylinder Cm to the image plane adjustment lens unit 5 and motion conversion of the rotational displacement of the image plane adjustment lens unit 5. If the structure is provided with the motion conversion mechanism 15 that converts the displacement into the optical axis direction Fc, a part of the existing focus adjustment mechanism 4 can be used together. There is an advantage that can contribute to cost reduction.

  By the way, the image plane adjustment lens unit 5 (image plane adjustment lens La) according to the present embodiment is a lens added according to the present invention, and at the forefront of the lens barrel C as shown in FIGS. Arranged at position Xf. The focus lens unit 3 is disposed at a position Xr behind the image plane adjustment lens unit 5. Therefore, if such a layout configuration is adopted, the focus lens unit 3 that is usually configured by a lens group including a plurality of lenses and has a large weight is located at a rear position Xr separated from the frontmost part of the lens barrel C. Therefore, it is possible to contribute to the reduction of the moment load applied to the support mechanism that cantilever-supports the rear end of the lens apparatus 1, and another lens is provided between the image plane adjustment lens unit 5 and the focus lens unit 3. For example, there is an advantage that the functionality and diversity of the lens device 1 can be enhanced, such as the fact that it is possible to dispose the fixed lens unit 11 whose position is fixed.

  Next, the operation (function) of the lens apparatus 1 according to the present embodiment will be described with reference to FIGS.

  Now, if a control signal (drive signal) is given to the rotation drive part 24, the drive gear 24g will rotate. This rotation is transmitted to the driven gear 2rg, and the focus ring 2r is rotationally displaced. That is, the focus ring 2r is rotated by an electric method. The rotational displacement of the focus ring 2r is transmitted to the intermediate cylinder Cm via the first connecting portions 31 ..., and the intermediate cylinder Cm is rotationally displaced. Then, the rotational displacement of the intermediate cylinder Cm is transmitted to the focus lens unit 3 through the first engagement portions 36, and the focus lens unit 3 is rotationally displaced. At this time, the lens holding cylinder 32 of the focus lens unit 3 is screwed to the zoom interlocking cylinder 33 via the motion conversion mechanism 15 using a helicoid screw mechanism, and the zoom interlocking cylinder 33 rotates in the circumferential direction. Since the displacement is restricted, the lens holding cylinder 32 of the focus lens unit 3 is displaced forward and backward relative to the zoom interlocking cylinder 33 in the optical axis direction Fc in accordance with the amount of rotational displacement of the focus holding lens 32. Thereby, focus adjustment, that is, focusing is performed.

  Further, if the intermediate cylinder Cm is rotationally displaced by the rotational operation of the focus ring 2r, this rotational displacement is simultaneously transmitted to the transmission cylinder 38 via the second connecting portions 37, so that the transmission cylinder 38 is rotationally displaced. To do. Further, the rotational displacement of the transmission cylinder 38 is transmitted to the lens holding cylinder 41 via the second engaging portions 43, so that the lens holding cylinder 41 is rotationally displaced. At this time, the inner peripheral surface of the lens holding cylinder 41 is screwed to the outer peripheral surface of the lens fixing cylinder 42 via the motion conversion mechanism 15 using a rehelicoidal screw mechanism, and the lens fixing cylinder 42 is fixed. Therefore, the lens holding cylinder 41 of the image plane adjusting lens unit 5 is moved forward and backward relative to the lens fixing cylinder 42 in the optical axis direction Fc in accordance with the amount of rotational displacement of the lens holding cylinder 41.

  In this case, the displacement direction and displacement amount in the optical axis direction Fc of the image plane adjustment lens unit 5 are image plane adjusted (image plane correction) with respect to the displacement amount of the focus lens unit 3 in the optical axis direction Fc described above. Thus, since the helicoid screw mechanism 43 and the image plane adjustment lens La are designed, a desired image plane adjustment corresponding to the focus adjustment is performed. That is, as shown in FIG. 3, when the focus lens unit 3 is displaced forward Fcf by the displacement amount Df, the image plane adjustment lens unit 5 is displaced by the displacement amount Dr corresponding to the rear Fcr. At this time, as the distance from the lens device 1 to the screen increases as the characteristic line Qs shown in FIG. 5, the image plane adjustment lens unit 5 is displaced to the rear Fcr, and the distance from the lens device 1 to the screen is shortened. As a result, the image plane adjustment lens unit 5 is displaced to the front Fcf, whereby focus adjustment (focusing) is performed by the focus adjustment mechanism 4 and image plane adjustment by the image plane adjustment mechanism 6 is also automatically performed. Phenomena such as a partial curvature or blurring of the image generated by the focal length are eliminated.

  Therefore, according to the lens apparatus 1 according to the present embodiment, the image plane adjustment lens unit 5 having the image plane adjustment lens La disposed in the lens barrel C so as to be displaceable in the optical axis direction Fc, the focus The image plane adjustment lens unit 5 is displaced in the optical axis direction Fc by a displacement amount that adjusts the image plane in accordance with the operation amount of the ring 2r, and thus includes an image plane adjustment mechanism 6 that adjusts the image plane. An independent image plane adjustment system such as displacing the lens by an electric drive system including a conversion mechanism or the like is not necessary, and the number of parts and assembly man-hours can be reduced, and the overall configuration can be simplified (simplified). . Therefore, it is possible to realize a significant cost reduction including both the component cost and the manufacturing cost, and to contribute to the reduction in size and weight of the entire lens apparatus 1. Since the operation of the focus ring 2r is simultaneously and directly transmitted to both the focus lens unit 3 and the image plane adjustment lens unit 5, the adjustment timings of both the focus adjustment and the image plane adjustment are always synchronized. Can be. Therefore, the delay in image plane adjustment can be eliminated, the responsiveness can be improved, the speed of image plane adjustment can be increased, and an adjustment system with high stability and smoothness can be constructed. In particular, as described above, in the case of the projector Pp, the screen size projected on the screen is large, and the bending phenomenon and blurring phenomenon that occur in a part of the image are easily noticeable. Therefore, from the viewpoint of effectively eliminating this problem, the projector It is optimal to apply to Pp.

  The preferred embodiment has been described in detail above, but the present invention is not limited to such an embodiment, and the detailed configuration, shape, material, quantity, and the like are within the scope not departing from the gist of the present invention. , Can be changed, added and deleted arbitrarily.

  For example, the lens apparatus 1 may be exchangeable with respect to the optical device P or non-exchangeable. In addition, the image plane adjustment lens La has been described as using a single aspherical lens Las, but it does not exclude the use of a compound lens or a lens group in which a plurality of lenses are combined. Furthermore, although the focus ring 2r has been exemplified as the focus adjustment operation unit 2, for example, a configuration in which the intermediate cylinder Cm is directly displaced by a linear drive unit may be employed. Therefore, in this case, the intermediate cylinder Cm also serves as the focus adjustment operation unit 2. Moreover, although the focus adjustment mechanism 4 illustrated the aspect using the existing (known) structure, it does not exclude various known structures other than the illustration.

  The lens device 1 according to the present invention can be used for various optical devices P including the exemplified projector Pp, a still camera, a video camera, and the like.

  DESCRIPTION OF SYMBOLS 1: Lens apparatus, 2: Focus adjustment operation part, 3: Focus lens part, 4: Focus adjustment mechanism, 5: Image surface adjustment lens part, 6: Image surface adjustment mechanism, 11: Fixed lens part, 12: Link mechanism part , 13: motion conversion function section, 14: link mechanism section, 15: motion conversion function section, 45: cylindrical cover, C: lens barrel, Cc: fixed cylinder section, Cm: intermediate cylinder, P: optical instrument, Pp: Projector, Fc: Optical axis direction, La: Image plane adjustment lens, Las: Aspheric lens, Xf: Front position of lens barrel, Xr: Position behind image plane adjustment lens section

Claims (4)

  In a lens apparatus of an optical apparatus including a focus adjustment mechanism that performs focus adjustment by displacing the focus lens unit in the optical axis direction by operating at least a focus adjustment operation unit provided in the lens barrel, the position of the foremost part of the lens barrel An image plane adjustment lens portion having an image plane adjustment lens disposed so as to be displaceable in the optical axis direction by being screwed to the outer peripheral surface of the fixed cylinder portion, and an intermediate cylinder rotated by the operation of the focus adjustment operation portion , A link mechanism for transmitting the rotational displacement of the intermediate cylinder to the focus lens disposed behind the image plane adjusting lens, and the motion of the rotational displacement of the focus lens to change the optical axis direction A focus adjustment mechanism having a motion conversion mechanism that converts the displacement into a displacement, and a link mechanism that transmits the rotational displacement of the intermediate cylinder to the image plane adjustment lens And a motion conversion mechanism that converts the rotational displacement of the image plane adjustment lens unit into a displacement in the optical axis direction, and adjusts the image plane according to the operation amount of the focus adjustment operation unit. And an image plane adjustment mechanism that adjusts the image plane by displacing the image plane adjustment lens unit in the optical axis direction by the amount of displacement to be performed, and the image plane adjustment lens unit also serves as a hood of the image plane adjustment lens A lens apparatus for an optical apparatus, comprising: a cylindrical cover that covers at least a part of the motion conversion mechanism section and the link mechanism section in the image plane adjustment mechanism.   2. The lens apparatus for an optical apparatus according to claim 1, wherein a fixed lens unit having a fixed position is disposed between the image plane adjustment lens unit and the focus lens unit.   The lens apparatus for an optical apparatus according to claim 1, wherein the image plane adjustment lens is a single aspheric lens.   4. The lens device for an optical device according to claim 1, wherein the lens device is applied to a projector as the optical device.

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