JP4856971B2 - Lens device - Google Patents

Description

  The present invention relates to a lens apparatus.

  Various adjustments such as zoom adjustment, focus adjustment, and iris adjustment of the lens device are performed by manual control or electric control. For example, zoom adjustment is performed by manually or electrically rotating a zoom ring that drives a lens built in the lens device. When the zoom ring is manually rotated, precise zoom adjustment can be easily performed by increasing the torque resistance (zoom resistance) generated when the zoom ring is rotated. On the other hand, when the zoom ring is rotated electrically, the power and power transmitted to the zoom ring can be saved by reducing the zoom resistance.

A lens apparatus is disclosed in which a small zoom resistance is set separately during manual control and a large zoom resistance is set separately during electric control so as to satisfy the zoom resistance desired during manual control and electric control of zoom adjustment (Patent Document 1). .) More specifically, the lens device is provided with two types of torque generating members that rotate in conjunction with the zoom ring. By switching the torque generating members that rotate using a lock gear between manual control and electric control, It is possible to obtain different zoom resistances.
Japanese Patent No. 3403146

  However, when the rotating torque generating member is switched using the lock gear as described above, there is a problem in that a harmful effect based on backlash occurs. In other words, since there is play in the gear, the zoom resistance suddenly increases or decreases immediately after switching the torque resistance or reversing the sign of the rotation direction of the zoom ring, which may adversely affect the operation.

  The present invention has been made in view of the above problems, and an object of the present invention is to switch between manual control of various adjustments and electric control, and to reverse the rotation direction of various operation rings. It is an object of the present invention to provide a new and improved lens apparatus which can always operate as a whole and obtain a desired torque resistance when performing various adjustments.

In order to solve the above problems, according to an aspect of the present invention, a lens apparatus is provided that performs zoom adjustment by driving a lens. This lens device has a cam mechanism that regulates the driving of the lens, a lens barrel with a built-in lens and a peripheral portion on the outer peripheral surface, a peripheral portion and a contact surface, and slides in the optical axis direction. by, it changes the contact area of the contact surface, and a sliding section for generating a torque resistance of offsetting the change in torque resistance generated by the lens of the zoom adjustment at the cam mechanism, the zoom ring that rotates during zoom adjustment of lens And a guide mechanism that slides the sliding portion in the optical axis direction in conjunction with the operation . According to such a configuration, the sliding portion adds up the torque resistance (cam resistance) generated by the cam mechanism and the torque resistance (additional resistance) generated at the contact surface in order to reduce the torque change generated by the cam mechanism. The obtained torque resistance (zoom resistance) can be obtained stably.

  The lens device further includes a position switching unit that moves the sliding part between at least two positions, that is, an electric control position at the time of electric control of zoom adjustment and a manual control position at the time of manual control. The sliding part may be configured to be larger when in the manual control position than when in the electric control position. According to such a configuration, the sliding portion always rotates integrally during zoom adjustment, and the contact area with the peripheral portion is switched by the sliding portion sliding on the contact surface based on the operation of the position switching portion. If the contact area changes, the torque resistance generated on the contact surface also changes. Therefore, a larger torque resistance (zoom resistance) can be obtained during manual control than during electric control.

The sliding portion and the peripheral portion may each include a comb tooth portion, and the contact surface may be configured by contacting the top surfaces of the comb tooth portions. According to such a configuration, the contact area is obtained by the contact between the top surface of the comb tooth portion of the sliding portion and the top surface of the comb tooth portion of the lens barrel. The torque resistance can be maximized when the top surfaces coincide with each other, and the torque resistance can be minimized when the sliding surface and the top surface of the comb teeth of the lens barrel are displaced and the contact area is extremely small. Further, when such a contact area is changed, a sufficient increase / decrease in zoom resistance can be obtained simply by moving the sliding portion by the width of the top surface of the comb teeth along the optical axis.
The guide mechanism is fixed to the sliding portion and moves in conjunction with the operation of the zoom ring, and a restriction that restricts the movement of the moving member in the rotation direction and the optical axis direction during zoom adjustment of the lens. It is good also as a structure which has a mechanism and makes a sliding part slide to an optical axis direction, when a control mechanism controls the movement of an optical axis direction of a moving member .
The moving member is a guide screw that is screwed into the sliding portion, and the restricting mechanism is formed in the zoom ring, and is formed in a guide groove as a moving path of the guide screw and in an arc shape, and the guide screw is rotated. It is good also as a structure which has a guide rail in which the groove | channel which controls the position to perform and the position of an optical axis direction was formed.
The sliding portion may be configured to be covered with the zoom ring.

  As described above, according to the present invention, when performing various adjustments regardless of switching between manual control and electric control of various adjustments, and whether the rotation direction of various operation rings is reversed, the whole is always integrated. The desired torque resistance can be obtained by operating.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted. In addition to zoom adjustment, the lens apparatus can also perform focus adjustment and iris adjustment. However, in the following description, a case where the lens apparatus according to the present embodiment is mainly applied to zoom adjustment will be described as an example.

(First embodiment)
FIG. 1 is a cross-sectional view of the lens device 100 according to the present embodiment during manual zoom control. FIG. 2 is an exploded perspective view showing the configuration of each part of the lens device main body 200 of the lens device 100. FIG. 3 is an explanatory diagram showing the relationship between the zoom ring 240 and the sliding portion 270 of the lens apparatus 100. FIG. 4 is a schematic external view showing the relationship between the lens apparatus main body 200 and the drive unit 300. Hereinafter, the configuration of each part of the lens apparatus 100 according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 1, the lens device 100 includes a lens device main body 200 and a drive unit 300. The lens apparatus main body 200 incorporates lenses such as the first moving lens group 210 and the second moving lens group 220, and moves each lens group along the optical axis based on control from the drive unit 300 during electric control. Zoom adjustment.

  The drive unit 300 includes a guide rail 310, a switching gear 320, a position switching unit 330, a servo motor 340, and a first stage gear 350.

  The guide rail 310 is formed in an arc shape, and has a groove 314 in the circumferential direction for restricting the rotating direction of the guide screw 272 and the position in the optical axis direction. In addition, the position of the guide rail 310 changes along the optical axis in conjunction with the switching gear 320.

  The switching gear 320 has two gears having the same rotation axis. One meshes with the first gear 350 of the servo motor 340 during electric control, and the other meshes with the zoom ring 240 gear. Further, a transmission means for moving the guide rail 310 in the optical axis direction of the lens apparatus 100 in conjunction with the switching gear 320 is provided.

  The position switching unit 330 changes the position of the switching gear 320 along the optical axis. Details of the configuration and operation of the position switching unit 330 will be described later.

  As shown in FIG. 2, the lens apparatus main body 200 includes a first moving lens group 210, a second moving lens group 220, a cam barrel 230, a zoom ring 240, a lens barrel 260, and a peripheral portion 264. And a sliding portion 270.

  The first moving lens group 210 and the second moving lens group 220 include a concave lens or a convex lens, and cooperate as a variable power lens to adjust the magnification of the subject.

  The cam cylinder 230 is formed in a cylindrical shape, includes a first cam groove 216 and a second cam groove 226, and has a role as a cam mechanism. The shapes of the first cam groove 216 and the second cam groove 226 are determined by the optical system, but in FIG. 2, the first cam groove 216 is formed in a straight line and the second cam groove 226 is formed in an arc shape. It is shown. Three first cam grooves 216 and two second cam grooves 226 may be provided so that the outer peripheral surface (center angle) of the cam cylinder 230 is equally divided into three.

  Such a cam barrel 230 includes a first moving lens group 210 and a second moving lens group 220. More specifically, the first screw 212 passes through the first cam groove 216 and is screwed into the first lens group 210. At that time, the first screw 212 contacts the edge of the first cam groove 216 via the first roller 214. Similarly, the second moving lens group 220 is screwed with a second screw 222 that passes through the second cam groove 226. At that time, the second screw 222 contacts the edge of the second cam groove 226 via the second roller 224.

  The zoom ring 240 has a gear 244 that meshes with the switching gear 320 on the drive unit 300 side. In addition, the zoom ring 240 is a guide that serves as a movement path for a through hole (not shown) of a third screw 250 for screwing the zoom ring 240 and the cam cylinder 230 and a guide screw 272 screwed to the sliding portion 270. A groove 242 is provided.

  The lens barrel 260 has the cam barrel 230 fitted therein, and has a first moving groove 218 for moving the first screw 212 and a second moving groove for moving the second screw 222 on the inner periphery. 228. These moving grooves 218 and 228 can be provided in the same number as the cam grooves 216 and 226, for example, three each. Further, a first comb tooth portion (peripheral portion) 264 is provided on one side of the outer surface of the lens barrel 260. The first comb tooth portion 264 may be configured by providing a number of grooves in the optical axis direction.

  The sliding portion 270 is a cylindrical member located between the lens barrel 260 and the zoom ring 240. A second comb tooth portion 274 is provided on the inner peripheral surface of the sliding portion 270. Similarly to the first comb teeth portion 264, the second comb teeth portion 274 may be configured by providing a large number of grooves in the optical axis direction. The sliding portion 270 also has a screw groove 276 that is screwed with the guide screw 272.

  Such zoom ring 240, lens barrel 260, and sliding portion 270 are in a positional relationship as shown in FIG. That is, the sliding part 270 covers the lens barrel 260, and the zoom ring 240 further covers the sliding part 270. Of these, only the sliding portion 270 can slide in the optical axis direction of the lens device 100 by the guide screw 272. FIG. 3 shows a state in which the top surfaces of the comb teeth of the lens barrel 260 and the sliding portion 270 are displaced, and the contact area is small.

  Further, as shown in FIG. 4, the guide rail 310 restricts the moving direction of the guide screw 272, and the switching gear 320 and the zoom ring 240 mesh with each other, so that the lens apparatus body 200 and the drive unit 300 are physically connected. Connected to

  The guide rail 310 has a rectangular parallelepiped protrusion 312 on the outer periphery. The guide rail 310 can move in a sliding groove 360 provided in the drive unit 300 via the protrusion 312. The drive unit 300 includes a zoom seesaw 370, detects a zoom instruction from the operator, and drives the servo motor 340.

  Next, the operation of the lens apparatus 100 according to the present embodiment will be described with reference to FIGS. FIG. 5 is a cross-sectional view of the lens apparatus 100 during zoom electric control. FIG. 6 is an explanatory view showing a state of contact between the lens barrel 260 and the sliding portion 270.

  First, transmission of power in the lens apparatus 100 will be described.

  During the electric control, the servo motor 340 is driven and becomes a power source for zoom adjustment. Torque generated by driving the servo motor 340 is transmitted to the zoom ring 240 via the first gear 350 and the switching gear 320. During manual control, the operator becomes a power source for rotating the zoom ring 240. The subsequent operations during electric control and manual control are the same.

  When the torque is transmitted (loaded), the zoom ring 240 rotates the cam barrel 230 and the sliding portion 270 based on the torque. When the cam cylinder 230 rotates, the first moving lens group 210 and the second moving lens group 220 move in the cam cylinder 230 along the optical axis. Further, when the sliding portion 270 rotates, a torque resistance (additional resistance) is generated based on a contact area with the first comb tooth portion 264 of the lens barrel 260.

  Subsequently, the switching operation of the contact area between the electric control and the manual control will be described.

  During manual control, precise zoom adjustment can be easily performed by increasing the torque resistance (zoom resistance) generated when the zoom ring is rotated. On the other hand, during electric control, the power and power transmitted to the zoom ring can be saved by reducing the zoom resistance. From this point of view, according to an embodiment of the present invention, a lens device is provided that can increase the contact area during manual control and reduce the contact area during electric control.

  In order to realize the above operation, the lens apparatus according to the present embodiment includes a position switching unit 330. When the position switching unit 330 shown in FIG. 5 is rotated counterclockwise during the electric control, the pin 332 included in the position switching unit 330 pushes the switching gear 320 leftward in FIG. Then, as shown in FIG. 1, the meshing between the switching gear 320 and the first gear 350 is disengaged, and the control is switched to manual control. Further, since the guide rail 310 follows the movement of the switching gear 320, the sliding portion 270 whose position in the steel axial direction is regulated by the guide rail 310 also slides on the outer surface of the lens barrel 260 in the left direction in FIG. To do.

  When the switching gear 320 is rotated clockwise during the manual control shown in FIG. 1, the switching gear 320 needs to return to the electric control position shown in FIG. Therefore, the switching gear 320 may be elastically biased in the right direction in FIG.

  The contact area may be larger at the time of electric control than at the time of manual control, but may be changed as shown in FIG. 6, for example. FIG. 6 shows a cross-sectional view of the lens barrel 260 and the sliding portion 270. The lens barrel 260 and the sliding portion 270 are cylindrical, and the first comb teeth portion 264 on the outer peripheral surface of the lens barrel 260 is provided with a plurality of grooves along the optical axis. The second comb tooth portion 274 on the inner peripheral surface is also provided with a plurality of grooves along the optical axis. The top surfaces of the first comb teeth portion 264 and the second comb teeth portion 274 that are convex portions between the grooves are in contact with each other and serve as contact surfaces. 6A shows the state of the contact area during electric control, and FIG. 6B shows the state of the contact area during manual control.

  At the time of the electric control, as shown in FIG. 6A, the top surface of the comb teeth of the lens barrel 260 and the sliding portion 270 is shifted to reduce the contact area. On the other hand, at the time of manual control, as shown in FIG. 6B, the top surface of the comb teeth of the lens barrel 260 and the sliding portion 270 can be matched to increase the contact area.

  As described above, according to the first embodiment of the present invention, after switching between electric control and manual control or after reversing the rotation direction of the zoom ring 240, a sudden increase / decrease in zoom resistance is prevented and stable. Zoom resistance can be obtained. That is, it is possible to obtain a continuous zoom resistance after the switching or after the rotation direction is reversed.

  The mechanism of the lens device 100 according to the present embodiment can also be applied to focus adjustment, iris adjustment, and the like. In this case, a member that rotates around the optical axis of the lens apparatus 100 in conjunction with the focus operation ring, the iris operation ring, the master ring, or the like functions as the sliding portion 270.

(Second Embodiment)
Next, a lens apparatus according to the second embodiment will be described. As shown in FIG. 2, when torque is supplied to the zoom ring 240, the zoom ring 240 transmits the torque to the cam barrel 230 via the pin 250. The cam cylinder 230 rotates based on the transmitted torque, and torque resistance (cam resistance) is generated due to friction between the first screw 212 and the second screw 222 at that time. Hereinafter, the cam resistance will be described with reference to FIGS.

  FIG. 7 is an explanatory view showing an example of the outer surface of the cam cylinder 230. FIG. 8 is a graph showing the relationship between the rotational position of the cam cylinder 230 and the cam resistance.

  The first cam groove 216 can be formed in a linear shape as shown in FIG. 7, and the second cam groove 226 can be formed in an arc shape. At this time, the cam cylinder 230 can rotate in the direction of the arrow in FIG. The shape and number of such cam grooves vary depending on the optical system, and an example is shown here.

  The friction generated through the first roller 214 between the first screw 212 and the first cam groove 216 is affected by the magnitude of the normal force generated at the edge of the first cam groove 216. Since the angle at which the extending direction of the first cam groove 216 intersects with the rotation direction of the cam cylinder 230 is substantially constant, the vertical drag is substantially constant regardless of the position of the cam cylinder 230. Therefore, the torque resistance resulting from the friction between the first cam groove 216 and the first screw 212 is also substantially constant, as shown by the straight line B in FIG.

  On the other hand, the friction and torque resistance generated via the second roller 224 between the second screw 222 and the second cam groove 226 is not constant unlike the above case. This is because since the second cam groove 226 is formed in an arc shape, the vertical drag generated at the edge of the second cam groove 226 varies depending on the rotational position of the cam cylinder 230. That is, as the angle at which the extension direction of the tangent line of the second cam groove 226 intersects with the rotation direction of the cam cylinder 230 is closer to the vertical, a larger vertical drag is generated. Therefore, near the points P and R shown in FIG. Large vertical drag is generated. Further, since the perpendicular drag generated as the angle at which the extension direction of the tangential line of the second cam groove 226 intersects with the rotation direction of the cam cylinder 230 approaches 0 becomes smaller, it occurs near the point Q shown in FIG. The vertical drag is reduced. This situation is as shown by curve C in FIG.

  The value obtained by adding the torque resistance generated in the first cam groove 216 and the second cam groove 226 is the cam resistance, as shown by the curve A in FIG. As described above, the cam resistance varies depending on the rotational position of the cam cylinder 230.

  However, if the non-uniformity of the cam resistance as described above is reflected in the zoom resistance, there is a possibility that the zoom operation is stably performed. Therefore, according to an embodiment of the present invention, there is provided a lens apparatus 400 that can reduce non-uniformity in cam resistance using an additional resistance. Hereinafter, the configuration of the lens apparatus 400 capable of obtaining a zoom resistance with reduced cam resistance non-uniformity will be described with reference to FIGS.

  FIG. 9 is an external view showing the shape of the guide rail 410 that realizes the additional resistance as described above. FIG. 10 shows a change in the contact area between the sliding portion 270 and the lens barrel 260 in this embodiment to which the guide rail 410 is applied. FIG. 11 is a graph showing the relationship between the zoom resistance, additional resistance, and cam resistance in the present embodiment to which the guide rail 410 is applied.

  As shown in FIG. 9, the guide rail 410 according to the present embodiment is formed in an arc shape, and a guide groove for restricting the moving direction of the guide screw 272 is also formed in an arc shape. Therefore, when the cam barrel 230 rotates, the degree of contact between the sliding portion 270 and the lens barrel 260 changes as shown in FIG.

  10A to 10C show changes in the contact area during electric control. At the time of electric control, when the guide screw 272 is located at the point p in FIG. 9, there is almost no contact area, and FIG. When the guide screw 272 moves to the point q in FIG. 9, the sliding portion 270 moves to the right, and the top surface of the comb teeth of the lens barrel 260 and the sliding portion 270 contacts about half (FIG. 10B). ). When the guide screw 272 further moves to the point r in FIG. 9, the sliding portion 270 moves to the left, and the contact area is almost lost again (FIG. 10C).

  FIGS. 10D to 10F show changes in the contact area during manual control. During the electric control, when the guide screw 272 is positioned at the point p in FIG. 9, the lens barrel 260 and the top surface of the comb teeth of the sliding portion 270 are in contact with each other about half (FIG. 10 (d). )). When the guide screw 272 moves to the point q in FIG. 9, the sliding portion 270 moves to the right, and the lens barrel 260 and the top surface of the comb teeth of the sliding portion 270 come into contact with each other (FIG. 10E). ). When the guide screw 272 further moves to the point r in FIG. 9, the sliding portion 270 moves to the left, and the lens barrel 260 and the top surface of the comb teeth of the sliding portion 270 again come into contact with each other about half (FIG. 10 ( f)).

  As described above, by making the contact area variable depending on the position of the guide screw 272, the additional resistance changes as shown by the curve D in FIG. Here, the additional resistance during the electric control is illustrated as an example. That is, it is possible to obtain an additional resistance that is higher than the curve D during manual control and whose shape is shown by a curve similar to the curve D.

  A value obtained by adding the cam resistance and the additional resistance is a zoom resistance, which is expressed as a straight line E in FIG. Thus, according to the present embodiment, it is possible to obtain a zoom resistance that reduces the cam resistance non-uniformity.

  In addition, as shown in FIG. 10, the cam resistance non-uniformity is reduced by shifting the degree of contact of the comb teeth about half of the top surface of the comb teeth between the electric control and the manual control. It is possible to obtain a stable zoom resistance that is different between control and manual control. That is, as illustrated in the first embodiment, when the degree of contact of the comb teeth is shifted by one comb tooth top surface during electric control and manual control, the sliding portion 270 is moved in the right direction. When moved, the contact area increases at the time of electric control, and the contact area decreases at the time of manual control, which may generate torque resistance contrary to the desired additional resistance. The present embodiment also corrects such problems.

  In the present embodiment, the switching unit 330 has been described as an example in which the degree of contact between the comb teeth is shifted by about half of the top surface of the comb teeth between the electric control and the manual control. However, the switching unit 330 is provided. It's okay to not. That is, even if the guide rail 410 is formed in a predetermined circular arc shape and is fixed without being switched between the electric control and the manual control, the cam resistance non-uniformity that varies depending on the rotational position of the cam cylinder 230 can be reduced. Can be killed.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the first embodiment, the case where the contact area is switched only between the manual control and the electric control has been described. However, the contact area may be switched by providing further steps. That is, by configuring the switching unit 330 so that the contact area can be further adjusted stepwise or continuously during manual control, different zoom resistances can be obtained according to the user's preference and purpose.

  Further, the contact area can be moved in the radial direction without sliding the sliding part 270 in the optical axis direction, that is, the contact area between the sliding part 270 and the lens barrel is not large or small. The presence or absence of the contact surface may be reflected in the additional resistance.

It is sectional drawing at the time of zoom manual control of the lens apparatus 100 by this embodiment. FIG. 3 is an exploded perspective view showing the configuration of each part of the lens apparatus main body 200 of the lens apparatus 100. FIG. 6 is an explanatory diagram showing a relationship between a zoom ring 240 and a sliding portion 270 of the lens apparatus 100. 2 is a schematic external view showing a relationship between a lens apparatus main body 200 and a drive unit 300. FIG. FIG. 5 is a cross-sectional view of the lens apparatus 100 during zoom electric control. It is explanatory drawing which showed the mode of contact with the lens barrel 260 and the sliding part 270. FIG. 5 is an explanatory view showing an example of an outer surface of a cam cylinder 230. FIG. 3 is a graph showing the relationship between the amount of rotation of a cam cylinder 230 and cam resistance. FIG. 6 is an external view showing the shape of a guide rail 410. It is explanatory drawing which showed the mode of the change of the contact area in this embodiment to which the guide rail 410 is applied. It is the graph which showed the relationship between the zoom resistance in this embodiment to which the guide rail 410 is applied, an additional resistance, and a cam resistance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100,400 Lens apparatus 200 Lens apparatus main body 210 1st moving lens group 220 2nd moving lens group 230 Cam cylinder 240 Zoom ring 260 Lens barrel 264 Peripheral part (1st comb-tooth part)
270 Sliding part 300 Drive unit 310, 410 Guide rail 330 Position switching part

Claims (6)

A lens apparatus for adjusting a zoom by driving a lens,
A cam mechanism for restricting driving of the lens;
A lens barrel containing the lens and having a peripheral portion on the outer peripheral surface;
By having the peripheral portion and the contact surface and sliding in the optical axis direction, the contact area of the contact surface changes, and the change in torque resistance generated by the cam mechanism during zoom adjustment of the lens is reduced. A sliding part that generates torque resistance;
A guide mechanism that slides the sliding portion in the optical axis direction in conjunction with the operation of a zoom ring that rotates during zoom adjustment of the lens;
A lens apparatus comprising: And a position switching unit that moves the sliding part between at least two positions, that is, an electric control position at the time of electric control of the zoom adjustment and a manual control position at the time of manual control.
The lens device according to claim 1, wherein a contact area of the contact surface is larger when the sliding portion is in the manual control position than when the sliding portion is in the electric control position.   The said sliding part and the said surrounding part are each provided with the comb-tooth part, The said contact surface is comprised by the contact of the top surfaces of the said comb-tooth parts, The said 1 or 2 characterized by the above-mentioned. Lens device. The guide mechanism is fixed to the sliding portion and moves in conjunction with the operation of the zoom ring, and the rotation direction of the moving member and the movement in the optical axis direction during zoom adjustment of the lens Has a regulation mechanism to regulate
4. The device according to claim 1 , wherein the restricting mechanism restricts movement of the moving member in the optical axis direction to slide the sliding portion in the optical axis direction. 5. Lens device. The moving member is a guide screw screwed with the sliding portion;
The restricting mechanism is formed in the zoom ring and forms a guide groove serving as a movement path of the guide screw, and an arc-shaped groove that restricts the rotation direction of the guide screw and the position in the optical axis direction. The lens device according to claim 4, further comprising a guide rail.   The lens apparatus according to claim 5, wherein the sliding portion is covered with the zoom ring.

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