JPS62267714A - Zoom lens - Google Patents

Abstract

PURPOSE:To prevent useless consumption of electric power, by providing a detecting means which detects the projection of a macro switching button at the time of switching between a zoom area and macro area and making a sensor unit settable to its off-state in the macro area by means of the detecting means. CONSTITUTION:A position control member 11 is provided with a switch 14 and, when switching from a zoom area to a macro area is made by operating a macro switching button, the switch 14 is actuated and a sensor unit 13 is set to its off-state. When the macro area is switched to the zoom area by operating an operation knob 9, on the other hand, the switch 14 is actuated and the sensor unit 13 is turned on. The switch 14 is provided at a stepped section of the boundary between the two end faces 11a and 11b of the position controlling member 11 on the wide side in the zoom area and, for example, the supply voltage to the sensor unit 13 can be supplied through the switch 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a zoom lens suitable for use in video cameras and the like.

[Conventional technology]

Some zoom lenses used in video cameras integrated with video tape recorders have not only a zoom function but also a close-up function. When performing a zoom action, the variator lens and compensator lens move in the optical axis direction by rotating the cam ring, and the focus lens moves in the optical axis direction by rotating the focus ring, allowing focus adjustment. It is done. Further, when performing close-up photography, only the compensator lens moves in the optical axis direction by rotation of the cam ring, and focus adjustment is performed. At this time, the focus lens has no effect. In this way, a zoom lens has an area for zooming and an area for close-up photography; the former is called a zoom area, and the latter is called a macro area, and operating the zoom lens in the macro area is called a macro operation.

An example of such a zoom lens is disclosed in Japanese Utility Model Publication No. 57-93909. A conventional zoom lens in which focus is automatically adjusted using a sensor will be described below with reference to FIG.

In the figure, a partially opened holding plate 4 is attached to the end of a fixed cylinder 6 having a partially opened bottom. , a cam ring 5, and rods 3a and 3b are held parallel to the optical axis. A variator lens L2 is attached to the rod 3a.
The holding frame l is slidably attached to the rod 3.
In b, a holding frame 2 holding a compensator lens L3 is shown.
is slidably mounted. The holding frame 1 is provided with a protrusion, and this protrusion fits into a spiral cam groove 5a provided in the cam ring 5. The holding frame 2 is also provided with a protrusion, and this protrusion is fitted into a spiral cam groove 5a provided in the cam ring 5. It fits into another spiral cam groove 5b provided in the ring 5.

A zoom ring 7 is rotatably provided on the outer surface of the fixed barrel 5, and the zoom ring 7 and the cam ring 5 are connected by a pin 8 passing through a through groove provided in the fixed barrel 6. Thereby, when the zoom ring 7 rotates, the cam ring 5 rotates, and the variator lens Lx and the compensator lens L3 move along the rods 3a and 3b (therefore, in the optical axis direction).

A focus ring 12 is attached to a part of the outer surface of the fixed barrel 6 via a helicoid screw (not shown), and the focus ring 12 allows the focus lens to
, is retained. When the focus ring 12 rotates,
The helicoid screw moves the focus ring 12 in the optical axis direction with respect to the fixed barrel 6, thereby moving the focus lens L to perform focus adjustment.

Such a zoom lens is provided with a motor 16 and a sensor unit 13 for automatic focus adjustment. The motor 16 is rotated by the output signal of the sensor unit 13 and rotates the focus ring 12, and the rotation axis of the motor 16 is provided on the outer periphery of the focus ring 12 and the gear portion 16a provided thereon. It is connected to the focus ring 12 by meshing with a gear.

As shown in FIG. 4, the sensor unit 13 includes a light-emitting element A that emits infrared rays, etc., a lens L that emits this infrared rays toward the subject, a lens L4 that makes infrared rays reflected from the subject enter, and a lens L4 that emits infrared rays reflected from the subject. A light receiving element B that receives infrared light is provided, and a signal corresponding to the infrared light receiving position of the light receiving element B is formed and supplied to the motor 16.

The light-receiving element B is held by a frame 18, which is slidably attached to the rod 17 and is also supported by a spring 1.
9, it is biased in the H direction along this rod 17. Further, the pin 20 is provided with a rotatable L-shaped arm C, one end of which abuts on a part of the frame 18 by means of a pin planted therein, and a pin 22 is also provided at the other end.
1 is planted, and this pin is the end surface 12a of the focus ring 12.
is in contact with. The arm C is biased by a biasing means (not shown) in the direction in which the pin 21 is pressed against the end surface 12a of the focus ring 12 (in the direction of arrow G). It is biased in the direction of arrow H via C. However, the position of the frame 18 with respect to the rod 17 (position in the arrow H, H' direction),
Therefore, the position of the light receiving element B is regulated by the state of the arm C. By the way, the state of arm C is its pin 2.
When the focus ring 12 moves in the optical axis direction, the arm C rotates in the direction of the arrow G or G', and therefore the light receiving element B moves in the direction of arrow H or H' force. In this way, the fixed barrel 6 of the focus ring 12
There is a one-to-one correspondence between the position of the light-receiving element B and the position of the light-receiving element B.

The light-receiving element B is composed of, for example, a two-split element, and the zoom lens is in the correct focus state when the light-receiving element B is in a position where a specific infrared light reception condition B (for example, the amount of light received by the two elements is equal) is achieved. The focus lens L1 is positioned as follows.

Therefore, if the light-receiving element B is not in this specific light-receiving state, a signal corresponding to the light-receiving state is formed by the negative output of the light-receiving element B, and this is used as an output signal of the sensor unit 13 to drive the motor 16 in FIG. supplied to Motor 1
6 is rotated by this signal, the focus ring 12 is rotated, and the focus lens L is moved in the optical axis direction. As the focus ring 12 rotates and moves in the optical axis direction, the arm C in FIG. 4 rotates in the direction of arrow G or G'.
The frame 18, and therefore the light receiving element B, moves in the direction of the arrow H or H'. At this time, the rotating direction of the motor 16 is the direction in which the light receiving element B is in the above-mentioned specific light receiving state, and the direction in which the light receiving element B
When the lens enters the above-mentioned specific light receiving state, the motor 16 is no longer supplied with a signal and stops, and the position setting of the focus lens L is completed and the correct focusing state is achieved.

In addition to the above configuration, there is further provided means for switching between the zoom range and the macro range and performing macro operations. This means includes an annular position regulating member 11 fixed to the outer periphery of the fixed barrel 6, an operating knob 9 fixed to the zoom ring 7, and a portion protruding from the operating knob 9, and a spring 9a.
and a macro switching button 10 which is biased outward (arrow 1') from the operating knob 9. Position regulating member 11
As shown in FIG. 5, the end portion has a two-stage structure, and two end surfaces 11a and 11b are formed. Further, a protrusion 10a is provided at the bottom of the macro switching button 10, and a spring 9
As shown in FIG. 5, due to the urging force of a, this protrusion 1
0a is in contact with either end surface 11a or 11b.

When the zoom lens is in the zoom range, the protrusion 10a of the macro switching button 10 is in contact with the recessed end surface 11a of the position regulating member 11. When the zoom ring 7 rotates, the protrusion 10a moves while contacting (or not contacting) the end surface 11a;
The range of movement of is limited by the stepped portion that is the boundary between the two end faces 11a and 11b. That is, in the zoom range, the protrusion 10a moves in the area of the end face 11a between these two step parts, thereby performing a zoom operation.

On the other hand, when performing a macro operation, the zoom ring 7 is turned all the way to the wide side of the zoom range, thereby moving the protrusion 10a to the end surface 11a''.

11b, then press the macro switch button 1.
0 against the biasing force of spring 9a! At the same time, the operation knob 9 is used to further rotate the zoom ring 7 toward the wide side. As a result, the protruding portion 10a of the macro switching button 10 comes into contact with the protruding end surface 11b of the position regulating member 11, and enters the macro area.

Thereafter, by operating the operating knob 9, the projection 10a of the macro switching button 10 moves while contacting the protruding end surface 11b of the position regulating member 11, and macro operation, that is, focus adjustment for close-up photography is performed.

In addition, the cam groove 5 of the cam ring 5 into which the protrusion of the holding frame 3a fits
In a, the part used in the macro area has an arc shape with respect to the optical axis, and the cam groove 5b into which the protrusion of the holding frame 3b fits has a spiral shape in the part used in the macro area. I am doing it. Therefore, in the macro range, the variator lens L2 is fixed, and only the compensator lens L2 moves to perform focus adjustment. The reason why focus adjustment is performed using the compensator lens L in this way is that even if the focus lens L is moved in the macro range, almost no effect can be obtained, and the focus state is detected by the automatic focusing device unit 13. This is because it becomes almost impossible.

As described above, automatic focus adjustment in the zoom range and manual focus adjustment in the macro range are possible.

[Problem that the invention seeks to solve]

By the way, in the above-mentioned conventional technology, the sensor unit 13 operates even in the macro range, and the drive current is supplied to the motor 16, making the focus lens L completely unnecessary.
1 will be driven.

For this reason, the light emitting element A in the sensor unit 13 emits light and wastes power, and the motor 16
The same applies to The power consumed by these devices is extremely large, and this poses a particularly serious problem for zoom lenses used in video cameras and the like that are powered by batteries.

SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens that solves these problems and can significantly reduce wasteful power consumption.

[Means for solving problems]

In order to achieve the above object, the present invention provides a zoom range/macro range switching and macro operation unit with a detection unit for detecting the protrusion of the macro switching button, and the detection unit allows the zoom range/macro range switching and macro operation unit to detect the protrusion of the macro switching button. , turns the sensor unit on and off.

[Effect]

When the detection means switches from the zoom range to the macro range, the sensor unit is turned off, and when the macro range is switched to the zoom range, the sensor unit is turned on.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram showing an embodiment of a zoom lens according to the present invention, in which 14 is a switch, and parts corresponding to those in FIG. 1 are given the same reference numerals and redundant explanations will be omitted.

In FIG. 1, the position regulating member 11 is provided with a switch 14, and when the macro switching button 1o is operated to switch from the zoom range to the macro range, the switch 14 is activated in accordance with this operation, and the sensor unit 13 is in the off state. Further, when switching from the macro range to the zoom range by operating the operating knob 9, the switch 14 is activated in accordance with this switching, and the sensor unit 13 is turned on.

As shown in FIG.
For example, the power supply voltage of the sensor unit 13 can be supplied via this switch 14. Switch 14 in this case
A known device that turns on and off each time it is operated can be used. However, the switch 14 itself does not turn on or off;
The switch between the power source and the sensor unit 13 may be turned on or off each time the switch 14 is operated by the macro switching button 1o. For the same reason, any sensor may be used instead of the switch 14.

〔Effect of the invention〕

As explained above, according to the present invention, the sensor unit is set to the OFF state in the macro range, so there is no power consumption by the motor for moving the sensor unit or focus lens, which is unnecessary. Power consumption can be prevented, and the life of the light emitting element and the motor in the acid sensor unit can be extended.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a zoom lens according to the present invention, FIG. 2 is an enlarged perspective view showing the main parts thereof, FIG. 3 is a block diagram showing an example of a conventional zoom lens, and FIG. 4 is a block diagram showing an example of a conventional zoom lens. FIG. 3 is a configuration diagram showing an example of the sensor unit, and FIG. 5 is an enlarged perspective view showing the zoom area/macro area switching means in FIG. 3. 5...Cam ring, 5a, 5b...Cam groove, 6...Fixed cylinder, 7...Zoom ring, 9
......Operation knob, 9a...Spring, 10
...Macro switching button, 10a...Protrusion,
11...Position regulating member, 11a, 11b...
...End face, 12...Focus ring, 13...
...Sensor unit, 14...Switch,
16...Motor, 16a...Gear part,
L...Focus lens, L2...
Variator lens, L3...Compensator lens. Figure 1 Section 2/4/II) Flute Figure 3

Claims (1)

[Claims] 1. An automatic focusing device that uses the output signal of a sensor unit consisting of a light emitting part and a light receiving part to drive a motor to move the focus lens to adjust the focus, and a macro operation fixed to the zoom ring. A macro switching button is attached to the operation knob for controlling the zoom ring, and the rotation range of the zoom ring is divided into a zoom range and a macro range by a protrusion provided on the macro switching button and a position regulating member fixed to a fixed barrel. In a zoom lens equipped with a zoom range/macro range switch and a macro operation means that enable switching from the zoom range to the macro range by operating the macro switch button, the zoom range/macro range A zoom lens comprising: a detection means for detecting a protrusion of the macro switching button at the time of switching, and configured such that the sensor unit can be set to an OFF state in the macro range by the detection means.