JPH06105207A - Image pickup device - Google Patents

Abstract

PURPOSE:To prevent an unintended change in a field angle due to the returning force of a telescopic end sensing switch. CONSTITUTION:In the image pickup device having magnification lens groups 7, 12, a manual operation zoom means 5 moving the lens groups 7, 12 in the optical axis direction, a power zoom drive means 23, and a telescopic end detection means 18 detecting it that the magnification lens groups 7, 12 reach the telescopic end, the manual operation zoom means 5 implements zooming and when the telescopic end detection means 18 detects it that the magnification lens groups 7, 12 reach the telescopic end, the power zoom drive means 23 is driven in the telescopic direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus for zooming by moving a zoom lens group (hereinafter referred to as a zoom lens) in the optical axis direction by a manually operated zoom means or a power zoom drive means. .

[0002]

2. Description of the Related Art Conventionally, in this type of image pickup apparatus, when a power zoom switch is turned on, a power zoom motor as a power zoom drive means is rotated and zoomed. During the zooming, a tele end detection means as a tele end detection means is provided. When the switch detects that the zoom lens has reached the telephoto end, the power zoom motor is stopped by the detection signal.

On the other hand, when the manually operated zoom knob as the manually operated zoom means is turned and zoomed without operating the power zoom motor, when the zoom lens reaches the tele end, it acts on the tele end detection switch and then rotates a little. By the way, it stops by contacting the mechanical end.

As the above-mentioned tele end detection switch, there are a non-contact type such as a photo interrupter and a contact type such as a leaf switch. However, the photo interrupter needs to constantly supply current, consumes a lot of power, increases cost, and has a large size. Therefore, a leaf switch is often used.

[0005]

However, in the above conventional example, when the leaf switch is used as the tele end detection switch, zooming is performed using the manually operated zoom knob, and when the zoom lens reaches the tele end, the zoom operation ring is used. Pushes the movable contact of the tele end detection switch, and when the manual operation zoom knob is released, the zoom operation ring is pushed back by the elastic restoring force of the movable contact of the tele end detection switch.

As described above, when the zoom operation ring is pushed back, the zoom magnification changes by the pushed back amount, and when the hand is released from the manually operated zoom knob, the photographed image changes. It was

It is an object of the present invention to obtain a photographing device which solves the above problems.

[0008]

According to the present invention, the manually operated zoom means for moving the zoom lens group in the optical axis direction, the power zoom drive means, and the zoom lens group reach the tele end. In an image pickup apparatus having a tele end detection switch for detecting that the zoom lens is zoomed by the manually operated zoom means, and when the tele end detection switch detects that the zoom lens reaches the tele end, By driving the power zoom drive means in the tele direction, the backlash of the power zoom drive means is eliminated in the tele end direction, and when the hand is released from the manually operated zoom knob, the zoom operation ring is elastic due to the movable contact of the tele end detection switch. It is not pushed back by the resilience.

[0009]

EXAMPLES Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view best showing the features of the present invention, and FIG. 2 is a horizontal sectional view of FIG. Figure 1,
In FIG. 2, 1 is a fixed lens barrel, 2 is a front lens barrel as a first lens barrel that holds the first lens group 3 and is helicoidally coupled with the fixed lens barrel 4, and 4 is the outer diameter of the fixed lens barrel 1. The zoom operation ring 5 is fitted in the shaft and regulated in the thrust direction, and zoom operation is possible by rotation about the optical axis.
A manual operation zoom knob as a manual operation zooming means used when manually operating the zoom lens 6, and a second zoom lens 6 which holds the second lens group 7 for zooming and is fitted to the bar 8 and whose rotation is restricted by the bar 9.
In this second lens barrel, the roller 10 of the second lens barrel is fitted to the lead cam of the zoom operation ring 4 and moves in the optical axis direction as the zoom operation ring 4 rotates. A third lens group 11 holds the third lens group 12 for zooming and is fitted to the bar 13 so that the roller 14 is fitted to the cam of the zoom operation ring 4 to move in the optical axis direction.
A lens barrel, 15 holds the fourth lens group 16, and is fitted into the inner diameter of the fixed lens barrel 1, a fourth lens barrel 17, 17 is a leaf switch base attached to the fixed lens barrel 1, and 18 is a zoom lens. A leaf switch for detecting that the second and third lens groups 7 and 12 for zooming reach the telephoto end by being pushed by the protrusion 19 on the operation ring 4, and 20 holds the fifth lens group 21. A fifth lens barrel which is fitted inside the fixed barrel 1 and screwed with a screw 22, and 23 is gear-coupled with the zoom operation ring 4, and is fixed to the fixed barrel 1 as power as a zoom driving means. It is a zoom motor.

Next, the operation of the first embodiment having the above structure will be described. The projection 24 of the zoom operation ring 4 is rotatable between the projections 25 and 26 of the fixed lens barrel, and when the manual operation zoom knob 5 is manually operated, the zoom operation ring 4 is rotatable between a and b. Therefore, the second lens barrel 7 and the third lens barrel 12 fitted to the cam of the zoom operation ring 4 move to change the magnification.

In this case, when the movable contact of the tele-direction switch or the wide-direction switch of the power zoom switch (not shown) is pressed, the power zoom motor 23 rotates, the zoom operation ring 4 rotates, and the manual operation zoom knob 5 operates. If the wide-direction switch is pressed, the zoom operation ring rotates up to b, and if the tele-direction switch is pressed, the leaf switch 18 for detecting the tele end is turned on in the position C. Stop at.

Leaf switch 18 for detecting the tele end
The operation when is entered will be described with reference to the flowchart of FIG. In step ST3-1, it is determined whether or not the leaf switch 18 is turned on. If NO, the operation is stopped as it is. If YES, that is, if the leaf switch 18 is turned on, the power zoom is performed in step ST3-2. It is determined whether the motor 23 is rotating, and if YES, it is left as it is, and if NO, that is, when the power zoom motor 23 is not rotating, it means that the zoom ring 4 is rotated by the manual zoom knob 5. Therefore, in step ST3-3, the power zoom motor 23 is rotationally driven to the tele side. As a result, the backlash of the gear portion of the power zoom motor 23 is blocked in the tele direction.

After the above operation, when the hand is released from the zoom operating ring, the zoom operating ring is pushed in the wide direction by the elastic restoring force of the movable contact of the leaf switch 18 for detecting the tele end, but the power zoom motor 23 Since the backlash of the gear is clogged, in order for the zoom operation ring 4 to rotate, it is necessary to rotate the stopped power zoom motor 23, and the pressing force by the elastic restoring force of the movable contact of the leaf switch 18 is required. Then, the power zoom motor 23 cannot be rotated to the wide side. Therefore, the disadvantage that the zoom operation ring 4 is pushed back and the zoom magnification is changed does not occur.

[0014]

As described above, according to the present invention,
When zooming to the tele end with the manual operation zoom means, the power zoom motor is rotationally driven in the tele direction by detecting that the zoom lens has reached the tele end with the leaf switch, eliminating the backlash of the gear part. Therefore, when you release your hand from the zoom operation ring at the telephoto end, the zoom operation ring will not rotate even if a rotating force is applied to the wide side due to the restoring force of the movable contact of the leaf switch. The effect is that changes can be reliably prevented.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an image pickup apparatus showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of FIG.

FIG. 3 is a flow chart for explaining the operation.

[Explanation of symbols]

 5 Manual operation zoom knob (manual operation zoom means) 7 Second lens group (variable magnification lens group) 12 Third lens group (variable magnification lens group) 18 Leaf switch (tele edge detection means) 23 Power zoom motor (power zoom) Drive means)

Claims (1)

[Claims] 1. A manual operation zoom means for moving the zoom lens group in the optical axis direction, a power zoom drive means, and a tele end detecting means for detecting that the zoom lens group has reached the tele end. In the image pickup device, zooming is carried out by the manually operated zoom means, and by the tele edge detection means,
An image pickup apparatus, characterized in that, when it is detected that the zoom lens group has reached the telephoto end, the power zoom drive means is driven in the telephoto direction.