JPH07199034A - Zoom lens adjusting device - Google Patents

Abstract

PURPOSE:To provide a zoom lens adjusting device which makes assembly adjustments fast by saving data on a shift in optical origin on a memory. CONSTITUTION:A zoom lens 13 is driven in an inclined angle direction and once an inclined angle detection switch 15 turns ON, the driving of the zoom lens 13 is stopped. Then the zoom lens 13 is driven in a wide-angle direction and once the detection of a Z-phase output ends, the zoom lens 13 is stopped. The zoom lens 13 stops on a wide-angle side a little from the position of the Z-phase output, so the value of the deviation and offset data from a temporary origin read out of an EEPROM 11 to the optical origin are calculated to set an optical origin. Thus, the deviation data between the position of a lens position reference means and the specific reference position of the lens are saved to easily find the optical origin, and the complexity of assembly adjustments is eliminated. Even if a shift in the origin is caused, adjustments are completed in a short time, so maintenance efficiency is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens adjusting device used for adjusting optical instruments such as cameras and observation instruments.

[0002]

2. Description of the Related Art For example, when power is supplied to an optical device having a camera lens to initialize the lens position, the lens position is initially undefined, and therefore the optical origin is always set. There is a need. For this optical origin search, an incremental rotary encoder or the like is used as a position sensor. That is, align the Z phase of this rotary encoder with the position of the optical origin,
Perform assembly work to enable initial settings.

[0003]

However, as in the above-mentioned conventional example, the work of aligning the Z phase with the optical origin is extremely difficult and complicated, and therefore the assembly work requires a long time. There is a problem that work efficiency is extremely poor.

The object of the present invention is to solve the above-mentioned problems,
It is an object of the present invention to provide a zoom lens adjustment device capable of performing assembly adjustment at high speed by storing optical origin deviation data in a memory.

[0005]

A zoom lens adjusting device according to the present invention for achieving the above object is a zoom lens having a plurality of lenses which are independently driven by a focusing operation or a zooming operation. Lens position detecting means for detecting, end point detecting means for indicating the movement limit of the lens, lens position reference means for indicating one or more detection positions by the lens position detecting means, and the lens position in the vicinity of the end point detecting means. It further comprises a reference position offset data storage unit for storing displacement data between the position of the reference unit and the predetermined reference position of the lens.

[0006]

The zoom lens adjusting device having the above structure is
First, the lens is driven in one direction to detect the position of the end point detection switch, and then it is driven in the opposite direction to detect the position of the lens position reference means, and the position of the lens position reference means and the predetermined reference position of the lens are detected. The origin is set based on the deviation data.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a block circuit configuration diagram of this embodiment. A lens group 1 including a zoom lens and a focus lens is fixed on a base 2, and the base 2 is mounted on a ball screw 3 of a predetermined length. They are engaged with each other and can move along the ball screw 3 as the ball screw 3 rotates. The ball screw 3 is directly connected to the motor 4, and the motor 4 is connected to the rotary encoder 5. Further, end point detection switches 6 and 7 for detecting the moving end points of the lens group 1 are provided near both ends of the ball screw 3, respectively. The end point detection switch 6 detects an end point on the motor 4 side of the lens group 1,
The end point detection switch 7 detects the end point of the lens group 1 on the side opposite to the motor 4.

The output of the rotary encoder 5 is connected to a counter 8 which calculates the number of rotations thereof, and the motor 4 is connected to the output of a driver circuit 9 for driving. Further, the counter 8, the driver circuit 9, and the end point detection switches 6 and 7 are C
It is connected to the PU 10, and an EEPROM (non-volatile memory) 11 is connected to the CPU 10.

When a signal from the CPU 10 is input to the driver circuit 9 and the motor 4 is driven to rotate the ball screw 3, the lens group 1 on the base 2 horizontally moves linearly. The rotation of the motor 4 is transmitted in synchronization with the rotary encoder 5, and the rotary encoder 5 outputs the two-phase output and reference pulse of the incremental method to the counter 8, and the output of the counter 8 is input to the CPU 10.

The rotary encoder 5 outputs the outputs of the A phase, the B phase and the Z phase which is a reference pulse as a, b and z, respectively, as shown in FIG. Here, the outputs a and b have a phase difference, and the output z is one pulse output per one rotation.

Here, as an example, a case of adjusting a broadcasting camera as shown in FIG. 3 will be described. Camera 1
A zoom lens 13 is attached to 2 and a zoom demand signal g and a focus demand signal f for controlling zooming and focusing are connected to drive the zoom lens 13.

As shown in FIG. 4, when the lens group 1 in FIG. 1 is the zoom lens 13, the end point detection switch 6 is the narrow-angle end detection switch 15, and the end point detection switch 7 is the wide-angle end detection switch 16, the zooming operation is performed. As a procedure for performing the optical origin of the zoom lens 13 for performing the method, first, a temporary origin by the Z phase is detected and then the optical origin is adjusted.

In FIGS. 4 and 5, when the zoom lens 13 is driven from the narrow-angle direction to the wide-angle direction, the rotary encoder 5 rotates one rotation or more, so that the Z phase is z1, z2, z3 near the narrow angle end. Shall be output at the position. Also,
The position of the narrow-angle end detection switch 15 is t, and the optical origin of the zoom lens 13 is origin O.

The adjusting means will be described with reference to the flowchart of FIG. 6. In step 11, the zoom lens 13
Is driven in the narrow-angle direction, and in step 12, it waits for the narrow-angle end detection switch 15 to be turned on. When it is turned on, driving of the zoom lens 13 is stopped in step 13, and then in step 14, the counter 7 is set to a counter clear mode in which the counter value of the counter 8 is set to 0 every time the output z of the Z phase is detected.

That is, in FIG. 5, the narrow-angle end detection switch 1
When the zoom lens 13 at the position t of 5 is driven in the wide angle direction, the Z-phase output z2 is detected, and this position is set as the position of the temporary origin. At this time, the counter value becomes 0. Therefore, in step 15, the zoom lens 13 is driven in the wide-angle direction, the detection of the Z-phase output z2 is waited for in step 16, and when the detection ends, the zoom lens 13 is stopped in step 17. To do. Next, at step 18, the counter clear mode of the counter 8 is released.

Unless the counter clear mode is released, the Z phase is output each time the rotary encoder 5 makes one rotation while the zoom lens 13 is being driven, and each time the Z phase output z is detected. This is to prevent the counter value of the counter 8 from becoming 0. Here, the Z-phase output z2 is detected, the counter value of the counter 8 becomes 0, and C
Even if the PU 10 stops the motor 4, the zoom lens 13 stops at a position slightly wider than the position of the Z-phase output z2 due to a time delay, so this position is referred to as a lens stop position S. At this time, the value of the counter 8 becomes 0 once upon detection of the Z-phase output z2, but the counter value advances by the amount that the zoom lens 13 deviates from the position of the Z-phase output z2, so that value is set to Pc. With such an operation, the detection of the temporary origin is completed.

Next, offset adjustment is performed between the temporary origin and the optical origin. Step 2 of the flowchart shown in FIG.
Offset data Pg from temporary origin to optical origin 0 with 1
Is read from the EEPROM 11. This value is a value determined by the assembly adjustment and is the EEPR connected to the CPU 10.
It is written in the OM 11. Step 22
The current counter value Pc is read from the counter with and the counter value from the optical origin to the current position is read in step 23.
Pn is calculated by the calculation of Pn = Pg + Pc, the counter value Pn is set again in the counter 8, and the optical origin finding is completed in step 24.

Finally, in step 25, the counter value Pn is transmitted as the zoom demand signal g, and the position command value is adjusted by the zoom demand signal g.

In the above description, the case where the optical origin exists in the direction of the narrow angle end of the zoom lens has been taken as an example, but the same applies when the optical origin exists in the direction of the wide angle end, and also in the focus lens. The optical origin can be set in exactly the same manner.

[0020]

As described above, in the zoom lens adjusting apparatus according to the present invention, the optical origin can be easily found by storing the deviation data between the position of the lens position reference means and the predetermined reference position of the lens. As a result, the complexity of the assembly adjustment is eliminated, and the adjustment is completed in a short time even if the optical origin deviates due to a change with time, so that the maintenance efficiency is improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment.

FIG. 2 is an output timing chart of the encoder.

FIG. 3 is a configuration diagram applied to a broadcasting camera.

FIG. 4 is a control mechanism diagram of a zoom lens.

FIG. 5 is an explanatory diagram near the optical origin of the lens.

FIG. 6 is a flowchart of temporary origin detection.

FIG. 7 is a flowchart of optical origin alignment.

[Explanation of symbols]

 1 Lens 3 Ball Screw 4 Motor 5 Encoder 6 Driver 7 Counter 8, 9, 15, 16 End Point Detection Switch 10 CPU 11 EEPROM 12 Camera 13 Zoom Lens

Claims (1)

[Claims] 1. A zoom lens having a plurality of lenses independently driven by a focusing operation or a zooming operation, a lens position detecting means for detecting a position of the lens, and an end point detecting means for indicating a movement limit of the lens.
A lens position reference means indicating one or more detection positions by the lens position detection means, and a reference position for storing deviation data between a position of the lens position reference means near the end point detection means and a predetermined reference position of the lens. A zoom lens adjusting device comprising: an offset data storage means.