JPH03260637A - Photographing mode switching device in lens device - Google Patents

Abstract

PURPOSE:To adjust the position of a lens by interlocking with switching of a mode by locking a front lens group to a reference position at the time of AF mode and executing an AF operation, and automatically resetting a rear lens group to the reference position after the lock is released. CONSTITUTION:The lens system is constituted of a front lens group 2, a zoom lens group 3 and a rear lens group 4, and at the time of manual mode, focusing is executed by the front lens group 2, and at the time of AF mode, focusing is executed by the rear lens group 4. In such a state, at the time of AF mode, by locking the front lens group 2 to a reference position, an AF operation is executed, and by releasing the lock, the rear lens group 4 is reset to the reference position and the manual mode can be executed. In such a way, the position adjustment of the rear lens group or the front lens group 2 can be executed by interlocking with a switching operation of a photographing mode, and the mode can easily be switched.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention is directed to a lens device mounted on a television camera or the like, in which there is a difference between a manual focus shooting mode and an autofocus shooting mode as shooting modes of the lens device. The present invention relates to a photographing mode switching device that allows switching.

[Prior Art] In recent years, lens devices attached to television cameras and the like have been equipped with so-called autofocus mechanisms that automatically adjust the focus according to the distance from the lens to the subject. developed and put into practical use. In addition to this autofocus shooting mode, the photographer can also shoot using manual focus, which allows the photographer to adjust the focus without looking at the viewfinder or monitor.
mode) and manual focus shooting mode (
There has also been proposed a configuration that allows switching between the two modes (hereinafter referred to as manual mode).

In this way, in order to enable photography in the two shooting modes 1 to 1, the lens assembly consisting of the front lens group for the focus system, the zoom lens group for the variable magnification system, and the rear lens group for the correction system, which constitute the lens device. In addition to the front lens group, the rear lens group also has a focus adjustment function.When manual mode is selected, the front lens group adjusts the focus, and when AF mode is selected, the rear lens group adjusts the focus. There is a type that allows you to adjust the focus.

[Problem to be Solved by the Invention 1] By the way, as mentioned above, when the lens device is provided with two shooting modes, the rear lens group cannot be moved to a predetermined reference position while shooting in the manual mode. When shooting in AF mode, the front lens group must be set at the reference position. Therefore, when shooting in manual mode,
When switching to a state for photographing in F mode, the position of the front lens group must be adjusted, and when starting photographing in manual mode, the position of the rear lens group must be adjusted. Since there are still unresolved issues such as how to adjust the lens position when switching modes, it is true that a lens device capable of switching between these two modes has not yet been put into practical use.

The present invention has been made in view of the above points, and an object of the present invention is to adjust the position of the rear lens group or the front lens group in reliable synchronization with the switching operation of the shooting mode. It is an object of the present invention to provide a photographing mode switching device for a lens device, which allows the photographing mode to be easily switched.

[Means for Solving the Problems 1] In order to achieve the above-mentioned object, the present invention provides a locking means for locking the front lens group at a reference position when an autofocus shooting mode is selected, and a locking means in which the locking means is in a locking state. a switching detection means that detects this and activates an autofocus mechanism when the locking means is released; and a switching detection means that displaces the rear lens group to a reference position based on a signal from the switching detection means when the locking means is unlocked. A feature of the camera is that it includes a reference position return mechanism that enables photographing in different modes.

[Operation] By adopting such a configuration, the AF mode can be selected by operating the locking means.
The front lens group can be fixed at the reference position by the locking means, and the autofocus mechanism can be operated. Furthermore, when the front lens group is released from being fixed by the locking means, the reference position return means is activated and the rear lens group is automatically returned to the reference position, making it possible to take pictures in manual mode.

[Embodiment 1] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

First, FIG. 1 schematically shows a schematic configuration of a lens device.

In the figure, ■ indicates a lens barrel, and the lens barrel 1
Inside, three lens groups are built in, consisting of a front lens group 2, a zoom lens group 3, and a rear lens group 4 from the subject side. These lens groups 2, 3.4 are moved by moving frames 5, 6.4, respectively, which are moved in the optical axis direction by external operation.
7, and as each moving frame 5, 6.7 moves, the front lens group 2. The zoom lens group 3 and rear lens group 4 can be moved in the optical axis direction.

Each of the moving frames 5, 6.7 is operatively connected to an actuating ring 50, 60, 70 that rotates around the optical axis so as to linearly interlock the moving frames 5, 6, 7 along the optical axis direction. Each of the actuating rings 50, 60, 70 is provided with a ring gear 5a, 6a, 7a, and each of the ring gears 5a, 6a, 7a is connected to a motor 8, 9, 10, respectively, as shown in FIG. The attached drive gears 8a, 9a, and 10a are meshed and connected.

By operating these motors 8, 9, 10 and rotating the drive gears 8a, 9a, 10a,
By moving the moving frames 5, 6.7, the front lens group 2.
Zoom lens group 3. The rear lens group 4 can be moved in the optical axis direction.

Furthermore, an actuation ring 50 operatively connected to the movable frame 5 in the front lens group 2 can be manually rotated. The aforementioned motors 8, 9,
A lens 10 is attached to the side surface of the lens barrel 1, and is attached to a clip house shifter 11.

Here, the zoom lens group 3 has a variable power system, and focus adjustment, that is, focusing, is performed by the front lens group 2 and the rear lens group 4. When shooting in manual mode, focus can be adjusted using the front lens group 2, and when shooting in AF mode,
Focus adjustment is performed by the rear lens group 4. For this reason, when shooting in manual mode, the rear lens group 4 must be fixed at a predetermined position, that is, the reference position, and when shooting in AF mode, the front lens group 2 must be fixed at the reference position. No.

When selecting the AF mode, the front lens group 2 is fixed at a predetermined position determined in advance in the design, or a locking mechanism 20 is provided for this purpose, and by operating this lock mechanism a20, The front lens group 2 is fixed at a predetermined position. Furthermore, when the locking mechanism 20 releases the front lens group 2, the reference position return means 40 automatically moves the rear lens group 4 to a predetermined position predetermined in design-E.

As shown in FIGS. 3 and 4, the locking mechanism 20 includes:
In order to move the front lens group 2 in the optical axis direction, a locking member 21 engages with an engagement groove 50b formed in an actuating ring 50 that is operatively interlocked with the moving frame 5 to rotate around the optical axis. , an operating member 22 for pushing and operating the locking member 21, and a pressing member 23 for elastically transmitting the pushing force to the locking member 21 when the operating member 22 is pushed. be done.

The locking member 21 is a support cylinder 24 protruding from the lens barrel 1.
It consists of a cup-shaped member with a bottom that is slidably attached to the front lens group 2, and a protrusion 25 that engages with an engagement groove 50b formed in the actuating ring 50 of the front lens group 2 is formed at the bottom of the member. When the protrusion 25 is inserted into the engagement groove 50b, it also engages into the groove 12a formed in the fixed ring 12 adjacent to the operation ring 50 in order to accurately position the operation ring 50. It is supposed to be done. A first spring 26 acts on the locking member 21 to bias the protrusion 25 in the direction of disengaging from the engagement groove 50b, and normally, the locking member 21 has a bottomed groove 21a provided therein.
A stopper holder 27 screwed into the support cylinder 24 is engaged with the stopper holder 27, and the stopper holder 27 is brought into contact with the groove end wall of the bottomed groove 21a, thereby regulating its uppermost position.

The pressing member 23 is slidably fitted within the locking member 21. A second spring 28 is elastically mounted between the bottom surface of the locking member 21 and a stepped portion 23a provided on the pressing member 23, and the pressing member 23 is pushed against the locking member 23 by the action of the second spring 28. It is biased in the direction that it protrudes from. The pressing member 23 is also provided with a bottomed groove 23b, a stopper bolt 29 is engaged with the bottomed groove 23b, and the stopper bolt 29 is brought into contact with the groove end wall of the bottomed groove 23b. By doing so, the top position is regulated.

The operating member 22 has an operating knob 30 that is provided on the outside of the lens clip housing 11 and can be manually operated by the photographer.
A lever 32 is attached to the tip of the rotating shaft 31. Then, when the operating knob 30 is rotated, the lever 32 or the pressing member 23 is pressed against the second spring 25.
It is configured so that it can be pushed in a direction that resists the movement.

When photographing in manual mode, the operating knob 30 constituting the operating member 22 is held in a state where the lever 32 connected via the rotation shaft 31 is separated from the pressing member 23. As a result, the locking member 21 of the locking member 21 is disengaged from the engagement groove 50b of the operating ring 50, and the operating ring 50 is rotated by the motor 8 or manually, and the focus is adjusted by the front lens group 2. You will be able to write.

On the other hand, when photographing in AF mode, the operation knob 30 is rotated. As a result, the lever 32 or the pressing member 23 is pressed. However, the protrusion 25 on the locking member 21 is not necessarily located at a position corresponding to the engagement groove 50b on the actuating ring 5°. For this purpose, the locking member 21 is activated by the biasing force of the second spring 28 that is elastically mounted between the locking member 21 and the pressing member 23, so that the protrusion 25
is pressed by the actuating ring 5o. Then, by operating the motor 8 or rotating the operating ring 5o manually, when the engagement groove 50b of the operating ring 5o is brought into a position where it matches the protrusion 25 of the locking member 21, The protrusion 25 engages with the engagement groove 5ob, and the actuation ring 5o is locked in that position. Therefore, the spring force of the second spring 28 is set to be stronger than the spring force of the first spring 26 at least when pressed by the pressing member 23 or the lever 32.

When the protrusion 25 of the locking member 21 engages with the actuation ring 50 as described above, the actuation ring 50 is positioned and fixed at the reference position to enable photography in the AF mode, or When photographing, the selection of this AF mode must be detected and the motor 10 that drives the rear lens group 2 must be controlled by a well-known AF control circuit. For this purpose, the lock mechanism 20 described above is provided with a switching detection means. This switching detection means is composed of a switch 33 and a switch operating piece 34 attached to the locking member 21 of the locking mechanism 20 in order to turn the switch 33 ON and OFF. Due to the displacement of the locking member 21 when the lock member 25 engages with the engagement groove 50b of the actuation ring 50, the switch actuation piece 34
The switch 33 is turned on by pressing the switch 33. by this.

The AF control circuit comes into operation.

Furthermore, when photographing in this AF mode, focus adjustment is performed by moving the rear lens group 4 in the optical axis direction. For this reason, when switching from AF mode to manual mode, it is necessary to return the rear lens group 4 to a predetermined reference position. Therefore, when the operating member 22 in the locking mechanism 20 is operated to separate the lever 32 from the pressing member 23, the pressing member 23 is projected by the action of the second spring 28, and the locking member is attached to the groove end wall of the bottomed groove 23b. It abuts against the stopper bolt 29 of 21. As a result, the force of the second spring 28 no longer acts between the pressing member 23 and the locking member 21, and the locking member 21 is displaced in the direction away from the operating ring 7° by the action of the first spring 26. As a result, the switch actuating piece 34 is separated from the switch 33 and the switch actuating piece 34 is moved away from the switch 33 or the leaf F.
The state will be as follows. As a result, the reference position return mechanism 40 operates and the rear lens group 4 returns to the reference position.

Therefore, the configuration of the reference position return mechanism 40 for the rear lens group 4 will be explained with reference to FIG.

This reference position return mechanism 40 consists of a potentiometer, an encoder, etc. attached to the drive gear [Oa] of the motor 10 that drives the actuation ring 70 of the rear lens group 4, and rotates to output a voltage signal corresponding to the position of the drive gear 10a. Compare the signal levels of the position detection means 41, the reference position signal output means 42 that outputs a voltage signal corresponding to a position signal of a preset reference position, and the rotational position detection means 41 and the reference position signal output means 42. and a comparator 43.

The output signal from this comparator 43 is input to a mode switch 44. This mode switch 44 switches the drive circuit 45 of the motor lO to the AF control circuit 46.
a drive state in the AF mode in which the drive is controlled based on a signal from the AF mode, a return operation state in which the rear lens group 4 is returned to the reference position when manual mode is selected, and a stop state in which the drive of the motor 1o is stopped when the rear lens group 4 is returned to the reference position. It is configured so that it can be switched between three states.

Therefore, when the manual mode is selected, as described above, the switch operation piece 34 is separated from the switch 33 and the switch 33 is turned on, and the switch 44 is switched to the mode 1 return operation state. As a result, the output signal from the rotational position detection means 41 and the force signal from the reference position signal output means 42 are compared in the comparator 43, and if there is a difference between the two signals, the motor drive signal is sent to the drive circuit 45. In response to this input, the motor 1o is operated, and the operating ring 70 is driven to rotate so that the rear lens group 4 is at the reference position. When the actuation ring 70 is displaced to the reference position of the lens group 4, the drive circuit 45 is switched to a stopped state. Here, if the reference position of the rear lens group 4 is the -blade side moving stroke end position, then the comparator 4
3 outputs a difference signal between the output signal from the rotational position detection means 41 and the reference position signal output means 42, the motor 10 only needs to be rotated in one direction.
There is no need to provide a separate mechanism for detecting the direction in which 0 should be rotated.

Meanwhile, operate the operating member 22 of the lock mechanism 20.

When the AF mode is selected, the switch 33 is turned OFF.
This switch OFF signal or mode switch 4
4, the drive circuit 45 is controlled based on the signal from the AF control circuit 46, and focus adjustment is automatically performed.

The present embodiment is constructed as described above, and its operation will be explained next.

First, in order to switch the photographing mode to the manual mode while the lens device is in the AF mode, the operating knob 30 of the operating member 22 of the locking mechanism 20 is operated to separate the lever 32 from the pressing member 23. As a result, the protrusion 25 of the locking member 21 is disengaged from the engagement groove 50b of the actuation ring 50, and the actuation ring 50 becomes unlocked, and the actuation ring 5o becomes rotatable.

Therefore, the photographer presses the activation switch (not shown) for the motor 8.
By manually operating the lens, the focus can be adjusted by rotating the actuating ring 50 and moving the front lens group 2 in the optical axis direction. Furthermore, by manually turning the tip of the lens barrel l, the operating ring 5o can be rotated, and the focus of the front lens group 2 can be adjusted.

Thus, when performing the focus adjustment using the front lens group 2 described above, the rear lens group 4 is fixed at a predetermined position. For this reason, the switch 33 is turned off by the displacement of the locking member 21, and this signal is input to the mode switch 44.

Therefore, the rear lens group 4 in the rotational position detection means 41
The position signal is input to the comparator 43, and this signal is compared with the output signal from the reference position signal output means 42. As a result, if there is a difference between the two sexes, this signal is sent to the drive circuit 45.
is input, the motor 10 is operated to rotate the operating ring 70, and the rear lens group 4 is moved to a predetermined position, and when this position is reached, the motor 10 is stopped.

On the other hand, when shooting in AF mode, the
) The operating knob 30 of the operating member 22 in the locking mechanism 20 is switched to a state in which the lever 33 or the pressing member 23 is pressed. As a result, Figure 3 (b
), the locking member 21 is caused by the action of the second spring 28 to cause its protrusion 25 to fit into the groove 1 of the fixing ring 12.
2a and is pressed against the surface of the actuating ring 50. The actuating ring 50 is then rotated by driving the motor 8 or by manual operation. When the actuating ring 50 is rotated in this way, the protrusion 25 slides along the surface of the actuating ring 50, and the actuating ring 50
When the engagement groove 50b or the protrusion 25 is brought into the position facing the protrusion 25, the protrusion 25 or the engagement groove 50b will fall into the engagement groove 50b, as shown in FIG. It will be positioned at the reference position.

At the same time, the switch operating piece 34 attached to the locking member 21 is activated to turn on the switch 33, and this switch ON signal is input to the mode switch 44, and a signal from the AF control circuit 46 is output. The operation of the motor 10 is controlled based on this, and the focus is automatically adjusted according to the distance of the subject.

In this way, by operating the operating knob 30 of the operating member 22 in the locking mechanism 20, it becomes possible to switch between the AF mode and the manual mode, making the mode selection operation extremely easy.

[Effects of the Invention] As explained above, the present invention enables, when either the auto focus shooting mode or the manual focus shooting mode is selected, the front lens group or the rear lens group is adjusted depending on the mode selection. Since the lens is configured to be displaced to a predetermined reference position, the position of the rear lens group or the front lens group can be reliably adjusted in conjunction with the simple operation of switching the photographing mode.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic configuration diagram of a lens device, FIG. 2 is a configuration explanatory diagram showing a drive mechanism for each lens group constituting the lens device, and FIG. 3 (a
) is a sectional view of the locking mechanism, FIG. 4(b) and FIG.
The sectional view and FIG. 5 are explanatory views of the configuration of the reference position return mechanism. 1: Lens barrel, 2: Front lens group, 3: Zoom lens group, 4: Rear lens group, 5, 6, 7: Moving frame, 8,
9゜10: Motor, 20: Lock mechanism, 21: Lock member, 22: Operation member, 23: Pressing member, 25: Projection, 3
o: Operation knob, 32 Nilever, 33: Switch, 34
: Switch actuation piece, 40: Reference position return mechanism, 411 Rotational position detection means, 42: Reference position signal output means, 43:
Intimidation device, 44: Mode switch, 45: Drive circuit, 46.
AF ffjl control circuit, 50.60.70: operating ring, 50b: engagement groove.

Claims (4)

[Claims] (1) A manual focus shooting mode in which the front lens group, variable power lens group, and rear lens group are arranged from the subject side, and the front lens group is moved to adjust the focus, and the rear lens group is moved to adjust the focus. In the lens device capable of switching to an autofocus shooting mode, the lens device includes a locking means for locking the front lens group to a reference position when the autofocus shooting mode is selected, and a locking means for detecting that the locking means is in a locking state. A switching detection means for operating an autofocus mechanism, and a standard for displacing the rear lens group to a reference position based on a signal from the switching detection means when the locking means is unlocked to enable photography in a manual focus photography mode. What is claimed is: 1. A photographing mode switching device for a lens device, comprising a position return mechanism. (2) The locking means includes an engagement groove provided in a movable ring that supports the front lens group, a locking member that can be engaged with and detached from the engagement groove, and a direction in which the locking member is always disengaged from the engagement groove. a biasing means for biasing the biasing member; an operating member for pressing the locking member in a direction to engage the engagement groove against the biasing member; and a space between the operating member and the locking member. 2. The photographing mode switching device in a lens device according to claim 1, further comprising a pressing means that is elastically connected. (3) The switching detection means is turned on or off depending on the state of engagement and disengagement of the locking member in the locking means with respect to the engagement groove.
A claim characterized in that the switch is configured with an FF switch (
2) Photography mode switching device in the lens device. (4) The reference position return mechanism includes rear lens position detection means for detecting the position of the rear lens group, reference position signal output means for outputting a position signal of the movable stroke end position of the rear lens group, and rear lens position detection means. and a comparison means for comparing the signal from the reference position signal output means with the signal from the reference position signal output means, and when the switching detection means detects that the manual focus shooting mode has been selected, the comparison means compares the signal from the reference position signal output means. Claim (1) characterized in that the rear lens group is moved to a state where the position signal of the rear lens group coincides with the reference position signal.
1) A photographing mode switching device in the lens device.