JP2787500B2 - Electric zoom lens barrel - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric zoom lens barrel in which zooming operation is powered.

"Prior art and its problems" In this type of electric zoom lens barrel, the clutch is switched by a lever or the like in order to switch between power zooming and manual zooming. However, since the lens barrel has operating members such as a focus ring and an aperture scale ring, it is difficult to provide such a switching lever and further provide a forward / reverse drive switch for the motor and a manual zoom operating ring. Met. Also, the operation becomes complicated. In order to further adjust the zoom speed, a separate volume is required.

[Object of the Invention] An object of the present invention is to provide an electric zoom lens barrel capable of switching between power and manual and controlling the direction of zooming with a zoom operation ring.
Still another object of the present invention is to provide a lens barrel that can control the zooming speed with the same zoom operation ring.

[Summary of the Invention] The present invention supports a zoom operation ring so that it can move not only in the rotation direction but also in the direction of the optical axis. When the manual zoom member is rotated via the operation ring, manual zooming is performed, and when the switch member is rotated, power zooming is performed.

That is, the electric zoom lens barrel according to the present invention is a zoom operation ring capable of performing a linear movement operation and a rotation operation in the optical axis direction, and is selectively operated in conjunction with the movement operation of the zoom operation ring in the optical axis direction. A manual zoom member and a switch member integrated with the zoom operation ring in the rotation direction, a manual zoom mechanism for performing zooming when the manual zoom member is rotated through the zoom operation ring, and a zoom operation ring. When the switch member is rotated through the motor member, the motor control circuit drives the zoom motor in the normal or reverse direction according to the rotation direction of the switch member, and zooming is performed by the normal or reverse rotation of the zoom motor by the motor control circuit. It is characterized by having a power zoom mechanism for performing the operation.

The motor control circuit is further provided with speed control means for controlling the rotation speed of the zoom motor depending on the magnitude of the rotation angle from the neutral position of the switch member, so that the zooming speed can also be controlled.

"Examples of the Invention" The present invention will be described below with reference to illustrated examples. In this embodiment, the present invention is applied to a two-group type electric zoom lens. The front group lens L1 is fixed to the front group frame 11, and the front group frame 11 is screwed to the helicoid ring 12 by the helicoid H. The front group frame 11 also has a straight guide projection 11a, which is fitted in a straight guide groove 13a formed in the focus ring 13 in the optical axis direction.

The rear group lens L2 is fixed to the rear group frame 14, and the rear group frame 14
The pin (not shown) implanted in the cam ring engages with a cam groove (not shown) provided in the cam ring 15. Similarly, a pin (not shown) implanted in the squeezing ring 16 is engaged with a cam groove (not shown) provided in the cam ring 15. The cam ring 15 is rotatably supported on the inner periphery of the fixed ring 17, and the rear group frame 14 and the squeezing ring 16 fitted on the inner periphery of the fixed ring 17 are located between the fixed ring 17. A linear guide mechanism (not shown) provided supports the linear guide mechanism so that only linear movement in the optical axis direction is possible. Therefore, when the cam ring 15 rotates, the rear group frame 14 and the aperture moving ring 16 move straight in the optical axis direction in a predetermined relationship determined by the cam groove provided therein. The diaphragm moving ring 16 has a diaphragm blade 18 and a light blocking ring 19, and the diaphragm blade 18 is opened and closed by a diaphragm lever 21 protruding rearward from the mount ring 20.

On the other hand, the helicoid ring 12 is provided with a cam groove (not shown), and a pin (not shown) set on the cam ring 15 is fitted into this cam groove. Therefore, when the cam ring 15 rotates, the front group frame 11 which moves straight by the straight guide groove 13a moves through the helicoid ring 12 in the optical axis direction. That is,
When the cam ring 15 rotates, the front lens group L1 and the rear lens group L2 move in the optical axis direction while changing the air gap in a predetermined relationship, and zooming is performed.

The cam ring 15 is rotationally driven together with the fixed ring 17 by a motor 22 fixed in the lens. The cam ring 15 can also be rotated by a manual lever 23 projecting in the radial direction.

The focus ring 13 is driven to rotate by the AF shaft 24.
The rear end joint portion 24a of the AF shaft 24 faces the mount ring 20, and receives rotation from the AF shaft on the camera body side. A gear 24b provided at the front end of the AF shaft 24 meshes with an internal gear 13b formed on the focus ring 13. Therefore, when the AF shaft 24 rotates, the focus ring 13 rotates, and the front group frame 11 is moved to the focus ring 1 by the fitting relationship between the straight guide groove 13a and the straight guide protrusion 11a.
Rotate with 3 When the front group frame 11 rotates, it moves in the optical axis direction according to the helicoid H, and focusing is performed.

Outside the focus ring 13, a fixed ring 25 is located. On the outer periphery of the fixed ring 25, a zoom operation ring 26, a switch ring 27, and a manual zoom ring 28 are rotatably supported.

The zoom operation ring 26 has two circumferential V-grooves A and B on its inner peripheral surface, and the fixed ring 25 has a click ball 29 that fits in the circumferential V-groove A or B, Ball 29
The plate spring 30 is provided for urging the outside outward (the second spring).
See figure). The zoom operation ring 26 is movable in the optical axis direction between two positions where the click ball 29 is fitted in the circumferential V-grooves A or B, and both positions are stable positions.

The switch ring 27 has a return column 31 (FIG. 1) and a brush pin 32 (FIG. 2) that protrude inward from the through hole of the fixed ring 25.

The return column 31 is a component of the neutral position return mechanism NR shown in FIGS. 6A and 6B. The return column 31 receives a symmetrical rotational urging force by a pair of neutral position return springs 33 supported on the fixed ring 25 side, and when no external force is applied to the switch ring 27, the return column 31 (that is, the switch ring 27) is Return to the neutral position N.
That is, the pair of neutral position return springs 33 symmetrically positioned with respect to the return column 31 each have its center coil portion 33a
And the legs 33b and 33c at both ends thereof are connected to the return column 31 and the pin 35.
It is hung on. At the same time, the leg 33b is hung on the neutral column 36 facing the return column 31. The pin 34, the pin 35, and the neutral pillar 36 are all fixed to the fixed ring 25.

The brush pin 32 has a brush 37 fixed to the inner end thereof, and the brush 37 is in contact with a code plate 38 fixed to the inner peripheral surface of the fixed ring 25. This brush 37 and code plate 38
Detects the turning direction of the switch ring 27 from the neutral position N and the turning angle (amount) thereof, and inputs the information to the motor control circuit 40 of the motor 22. Motor control circuit 40
Receives the input of the rotation direction and the rotation angle, and receives the motor 22 via the rotation direction control circuit 40a and the speed control circuit 40b.
The rotation direction and the rotation speed are controlled (FIG. 5).

The movement of the manual zoom ring 28 in the optical axis direction is restricted by a step portion of the fixed ring 25 and a cover ring 42 fixed to a rear portion of the fixed ring 25. On its inner surface, a linear groove 28a in the optical axis direction is formed, and the manual lever 23 is fitted in this linear groove 28a. The straight groove 28a is formed for assembly, and does not move the manual lever 23 and the manual zoom ring 28 in the optical axis direction.

As shown in FIG. 4, an alternative meshing mechanism (clutch mechanism) 44 is provided on the zoom operation ring 26, the switch ring 27, and the manual zoom ring 28. The alternative meshing mechanism 44 is provided with a projection 26a on the end face of the zoom operation ring 26 on the switch ring 27 side, and is provided with an evenly spaced groove 27a on the switch ring 27 in which the projection 26a can be disengaged. The equally spaced grooves 26b are provided on the end surface on the side of the manual zoom ring 28, and the manual zoom ring 28 is provided with projections 28b that can be fitted into any of the equally spaced grooves 26b. These projections and grooves do not engage with each other at the same time. When the zoom operation ring 26 is advanced and the click ball 29 is fitted into the circumferential V-groove B, the projections 26a engage with the equally-spaced grooves 27a, and the zoom operation is performed. When the click ball 29 is fitted into the circumferential V-groove A by retracting the ring 26, the equally-spaced groove 26b and the projection 28b
Are engaged.

Reference numeral 45 denotes a graduation scale ring located at the rear of the cover ring 42, 46 denotes a distance scale window formed in the fixed ring 25, and 47 (FIG. 3) denotes a cover ring.
Reference numeral 48 denotes a focal length window formed in the reference numeral 42, and reference numeral 48 denotes a rotation range restricting projection of the focus ring 13 fixed to the fixed ring 25. From the distance scale window 46, a distance scale 49 attached to the outer peripheral surface of the focus ring 13 can be viewed, and from the focal length window 47, a focal length scale 50 attached to the outer peripheral surface of the manual zoom ring 28 can be viewed. be able to. The rotation range restricting projection 48 fits into a circumferential groove 13c provided at a predetermined angle on the outer periphery of the focus ring 13 to restrict the rotation range of the focus ring 13.

Accordingly, in the electric zoom lens barrel having the above-described configuration, the zoom operation ring 26 is advanced, and the click ball 29 is fitted into the circumferential V groove B in the electric zoom mode.
In this state, the zoom operation ring 26 and the switch ring 27 are integrated in the rotation direction due to the fitting relationship between the projection 26a and the equally-spaced groove 27a. When the switch ring 27 is rotated from the neutral position N to one of the positions via the zoom operation ring 26, the brush 37 and the code plate 38 first detect the direction of rotation, and the motor control circuit 40
(The rotation direction control circuit 40a) drives the motor 22 in either the forward or reverse direction. That is, the tele-wide zooming direction is controlled by the rotation operation direction of the zoom operation ring 26. The brush 37 and the code plate 38 are simultaneously connected to the switch ring 27, that is, the zoom operation ring.
The rotation angle of the motor 26 is detected, and the motor control circuit 40 (the speed control circuit 40b) increases the speed of the motor 22 as the rotation angle increases. When the motor 22 is driven, the cam ring 15 rotates,
The front group lens L1, the rear group lens L2, and the stop moving ring 16 move in the optical axis direction in a predetermined relationship, and zooming is performed.

The change of the zoom speed may be continuous or stepwise. These can be freely set by setting the code of the code plate 38 or by signal processing.

When the zoom operation ring 26 is rotated from the neutral position N to forward or reverse, as shown in FIG.
Only one of them bends. When the operating force is released, the switch ring 27 returns to the neutral position N via the return column 31 by the force of the leg 33b of the neutral position return spring 33 that has been bent, and the motor 22 stops. When returning, neutral pillar 36
Prevents excessive deformation of the leg 33b and prevents the switch ring 27 from rotating beyond the neutral position N. The above-described return operation is the same regardless of whether the zoom operation ring 26 is rotated forward or backward (tele, wide).

FIG.6C shows another embodiment of the neutral position return mechanism NR, in which the coil spring 33 and the pin 34 are one, and a pair of legs 33d of the coil spring 33 are on both sides of the neutral column 36 and the return column 31. Is contacted. According to this embodiment, a similar neutral position return operation can be obtained.

Next, in the manual zoom mode, the zoom operation ring 26 is retracted, and the click ball 29 is fitted into the circumferential V-groove A. In this state, the equally-spaced grooves 26b mesh with the protrusions 28b. The zoom operation ring 26 and the manual zoom ring 28 are integrated in the rotation direction. Therefore, when the zoom operation ring 26 is rotated, the cam ring 15 is rotated via the linear groove 28a and the manual lever 23, and zooming is performed.

The difference between the electric mode and manual mode is that the cam ring
This is the difference between rotating the motor 15 via the motor 22 and the motor 15 via the manual lever 23. In either case, zooming is performed.

Note that, also in the electric zoom mode, the manual lever 23 rotates together with the cam ring 15 and the manual zoom ring 28 rotates, but there is no problem because the manual zoom ring 28 and the zoom operation ring 26 are not engaged.

In the above embodiment, the manual zoom ring 28 is interposed in order to transmit the rotation of the zoom operation ring 26 to the manual lever 23. However, when the zoom operation ring 26 is slid backward, the manual operation ring 28 can be omitted if the zoom operation ring 26 and the manual lever 23 are directly engaged to be integrated in the rotation direction. . It is clear that the present invention does not ask the configuration of the zooming mechanism itself. The motor is rotated by forward / reverse rotation of the switch ring 27.
The mechanism can be applied to any mechanism as long as zooming is performed by driving the motor 22 in the forward and reverse directions, and mechanical zooming is performed by the forward and reverse rotation of the manual lever 23.

[Effects of the Invention] As described above, according to the electric zoom lens barrel of the present invention, when the zoom operation ring is moved in one direction in the optical axis direction and is rotated in the forward or reverse direction, the zoom operation is performed in the other direction. If the camera is turned to, manual zooming can be performed.
Therefore, switching between power and manual can be performed without increasing the number of operation members. In addition, since the switching is performed by moving the zoom operation ring back and forth, it is possible to perform switching without discomfort in either vertical position shooting or horizontal position shooting.

According to the second aspect of the present invention, at the time of electric zoom, the zoom speed can be changed according to the magnitude of the rotation angle of the zoom operation ring.

[Brief description of the drawings]

1 and 2 show an embodiment of an electric zoom lens barrel according to the present invention. FIG. 3 is a sectional view on the wide-angle side and a telephoto side, respectively. FIG. 3 is a perspective view showing the same appearance. FIG. FIG. 5 is a control block diagram of the motor in the lens barrel. FIGS. 6A and 6B show an example of a switch ring neutral position returning device. FIG. 6A shows a neutral position and 6B. The figure is a developed plan view of a main part showing a state during zooming. FIG. 6C is a developed plan view showing another example of the neutral position return device of the switch ring. L1… front group lens, L2… rear group lens, 11… front group frame,
11a: straight guide projection, 12: helicoid ring, 13: focus ring, 13a: straight guide groove, 13b: internal gear, 14
… Rear group frame, 15… Cam ring, 16… Aperture moving ring, 17 …… Fixed ring, 18… Aperture blade, 19 …… Light shielding ring, 20 …… Mount ring, 21 …… Aperture lever, 22 ………………………………………………………………………………………………………………………………………………………………………………………………………………. 27a ... equidistant groove, 28 ... manual zoom ring (member), 28a ... linear groove, 28b ... protrusion, 29 ... click ball, 30 ... leaf spring, 31 ... return column, 33 ... neutral Position return spring, 34, 35… pin, 36… neutral pillar, 37…
Brush, 38 Code board, 40 Motor control circuit, 40a
…… Rotation direction control circuit, 40b …… Rotation speed control circuit, 42
... Cover ring, A, B... Circumferential V groove, H... Helicoid, N... Neutral position, NR... Neutral position return mechanism.

Claims (2)

(57) [Claims] 1. A zoom operation ring capable of performing a linear movement operation and a rotation operation in the optical axis direction; and interlocking with the movement operation of the zoom operation ring in the optical axis direction, the zoom operation ring is selected. A manual zoom member and a switch member integrated in the rotation direction; a manual zoom mechanism for performing zooming when the manual zoom member is rotated via a zoom operation ring; and the switch member via a zoom operation ring. A motor control circuit for driving the zoom motor in the forward or reverse direction according to the turning direction of the switch member; and a power zoom for performing zooming by the forward or reverse rotation of the zoom motor by the motor control circuit. An electric zoom lens barrel comprising a mechanism. 2. An electric zoom lens barrel according to claim 1, wherein said motor control circuit includes speed control means for controlling a rotation speed of said zoom motor according to a magnitude of a rotation angle from a neutral position of said switch member.