JPH0436712A - Optical control device - Google Patents

Abstract

PURPOSE:To attain effective zooming even if the fixing position or opening/ closing position of a reset switch is not strictly controlled by providing the optical control means with an element for storing a distance between an origin and the reset switch, and at the time of producing the device, storing the measuring value of the distance. CONSTITUTION:A distance 114 between an origin position and a reset switch position 113 is previously measured in each lens system and stored in a memory 118. A focus lens 105 is moved at the time of turning on a power supply and stopped when the reset switch (SWR) is closed. At this point of time, a storage value corresponding to the distance 114 is read out and inputted to a lens position detecting counter. When the value of the counter entered into a normal operation range 117, normal operation is started. Since distance information between the fixing position of the SWR and the origin position starting the normal operation range is stored in the memory 118, the origin can be accurately set up in the moving range of the lens 105 and the rigid control of the fixing accuracy of the reset switch or the like can be made unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical control device, and more specifically, a lens position control device that adjusts a focus or changes magnification by moving a group of lenses. It is suitable for use in

[Prior Art] Looking at recent camera trends, in order to give the lens system distinctive performance and to make it more compact, lenses that adjust the focus by moving the rear lens, so-called Inner focus lenses are widely used.

FIG. 7 shows an example of the lens configuration of this inner focus type lens system. In the figure, 101 is a fixed first lens group, and 102 is a second lens group for variable magnification. (zoom lens), 103
701 is an aperture diaphragm, 104 is a fixed third lens group, 105 is a fourth lens group (focus lens) that also functions to adjust the focus and correct focal plane movement accompanying the magnification changing operation by the second lens group; is the imaging surface.

FIG. 8 shows the locus of the fourth lens group for obtaining a focused image on the imaging surface with respect to changes in focal length in this type of lens, using subject distance as a parameter. As mentioned above, the fourth lens group 105 has the functions of focus adjustment and focal shift correction associated with zooming, so it has a unique correction curve with respect to the subject distance. That is,
When zooming, it is necessary to select one of the correction curves shown in FIG. 8 according to the subject distance and move the fourth lens group 105 along this selection.

As a method of moving the lens group 105 shown in FIG. 7 during zooming along a correction trajectory specific to the subject distance, for example, Japanese Patent Application Laid-Open No. 1-280709 has been proposed.

According to this method, the group of trajectories shown in FIG. 8 is divided into a plurality of regions as shown in FIG. 9, each having a substantially equal slope, and one representative speed is assigned to each region. Assuming that the fourth lens group 105 is in the in-focus position with respect to the subject before the zoom operation starts, the ninth lens group 105
One divided area in the figure is determined, and at the same time as the start of the zoom operation, the representative speed of the fourth lens group to be driven, that is, the focus lens 105 is determined. When the zoom operation is started, the focal length and the position of the focus lens 105 change every moment, so the area shown in FIG. 9 changes each time, and the typical speed of the focus lens also changes.

By connecting the displacements corresponding to the changes in the representative speed, it is possible to obtain a curve that approximates the curve shown in FIG. 8, and it becomes possible to perform a zoom operation while patrolling.

According to the above method, the divided areas shown in FIG. 9 are correctly selected, and the focus lens 1
05 must be moved. Therefore, as the actuator for the focus lens 105, a stepping motor or the like that is easy to control the position and has a wide dynamic range of speed change is often used, and the position of the focus lens 105 is determined by counting the number of driving pulses of the motor. It is something.

Therefore, since the counter is an increment type position encoder, if an action that causes the contents of the counter to volatize, such as turning off the power, it is necessary to perform a reset operation to associate the position of the focus lens 105 with the contents of the counter. There is.

Therefore, as shown in FIG. 8 801, a reset switch is installed at a certain distance from the origin 802 of the graph, and when performing a reset operation, the focus lens 105 is temporarily moved to the position 801, and then the counter is set at a certain distance from the origin 802. A method of substituting the position of 801 can be used.

[Problems to be Solved by the Invention] However, in the above conventional example, the reset switch 80
1 and the origin 802 must be maintained accurately and accurately, it not only takes a lot of time and special equipment to position the reset switch 801 during manufacturing (but also prevents measurement errors from occurring in the process). Since a reset switch must be selected for each reset switch, there is a drawback that the cost increases significantly.

[Means for Solving the Problems] The present invention has been made with the aim of solving the above-mentioned problems, and is characterized by an object that changes its optical state by moving in a predetermined direction. a driving part, a detection means for detecting the position of the driven part, a storage means for storing information regarding a reference position of the driven part, and a reference position information stored in the storage means and an output of the detection means; Based on the invention, there is provided an optical control device including a control means for positioning the driven part to the reference position.

Other features of the present invention include: a driven part that changes its optical state by moving in a predetermined direction; a detection means that detects when the driven part is at a predetermined position near its reference position; a storage means for storing information indicating a relationship between the predetermined position and the reference position; and positioning the driven part to the reference position based on the information stored in the storage means and the output of the detection means. An optical control device comprising a control means.

[Function] Accordingly, when the present invention is applied to a lens system or a camera system, an element that stores the distance between the origins 802 and 801 is provided, the distance is measured during manufacturing, and this value is stored in the storage element. By storing the reset switch in the memory, it is possible to perform good zooming even without strictly controlling the mounting position of the reset switch and the opening/closing position of the reset switch.

[Example] Hereinafter, an example of the optical control device according to the present invention will be described in detail with reference to each drawing.

FIG. 1 is a block diagram showing the configuration of an embodiment of an optical control device according to the present invention.

In the same figure, 101.102.103.104 and 1
05 is an element of the optical system having the same function as that shown in FIG.

Reference numeral 106 indicates an actuating member made of an insulating material, which is fixed so as to move together with the focus lens 105, and which pushes in a reset switch, which will be described later, when the focus lens moves to the infinity end. Reference numerals 107 and 108 each constitute a leaf switch. 109 is a power supply, 110 is a resistor, 112 is a control microcomputer (hereinafter referred to as microcomputer), and 113 is a reset position corresponding to position 801 of the reset switch set to the ω end side in FIG. , 114 is the distance from the origin position 802 in FIG. 8 to the reset switch position 113, 115 is the movable range of the focus lens 105, 116 is each curve in FIG. 8 rearranged according to the arrangement of the lens groups, Reference numeral 117 indicates the range of movement of the focusing lens 105 in a normal use state, that is, a state in which the focusing lens moves together with the zoom lens and can perform zooming while keeping the focus.
118 is each zoom lens II! This is a non-volatile memory that stores information regarding the distance 114 according to the (divided area).

In the lens system shown in FIG.
When the adjustment of 01, that is, the front lens adjustment is completed, the first group lens, the second group lens, 101, 102 . The positional relationship of the aperture 103, the third lens group, and the fourth lens group 104405 corresponding to changes in focal length and subject distance is fixed.

That is, the position of the origin of each curve 116 is fixed with respect to the arrangement of the lens groups.

On the other hand, since the leaf switches 107 and 108 constituting the reset switch SWR are assembled without adjustment, the distance 114 ends up varying between individual lens systems. By measuring this distance 114 in each lens system and storing it in the memory 118, it becomes possible to omit the troublesome position adjustment of the reset switch as in the past.

FIG. 2 is a flowchart of a program for measuring the distance 114 between the origin of the focus lens position and the reset position and for inputting the measurement result into the storage element 118 and adjustment work.

In the figure, 201 is a step showing the start of program execution, 202 is a step showing lens assembly and attaching the reset switch SWR without adjustment as described above, 203 is a step for adjusting the front lens, and 204 is a step showing the zoom lens 102. 205 is a step of moving the focus lens 105 to the subject 1 placed at a predetermined subject distance to focus on the imaging surface; 206 is a step of focusing the focus lens 105 on the imaging surface; Step 207 writes the designed position of the focus lens 105 (the in-focus position at the wide end of the subject distance used in step 205) in the position detection counter, and starts counting from the value written in step 206. step 20 of moving the focus lens 105 to the reset switch SWR side while
8 is a step of determining whether the reset switch SWR is closed, 209 is a step of stopping the focus lens 105, and 210 is a step of storing the count value at the time of step 201 in the nonvolatile memory 118.

When the work is started in step 201, step 202
At step 203, each lens is assembled and the reset switch SWR is installed, and at step 203, the front lens is adjusted.

Next, the zoom lens 102 is moved to the wide end, and in step 205, the focus is set on a reference subject for adjustment at a predetermined subject distance. For example, if the reference subject distance is 1 m, the focal point will be at point A in FIG. 8 at the wide end. Therefore, if the focus is on the wide end, the value of the position detection counter of the focus lens 105 should correspond to point A, so in step 206 the value corresponding to A is substituted into the counter. do. For example, when a stepping motor is used as an actuator for the focus lens 105, the value corresponding to A is equivalent to the number of driving steps from the origin to the point A.

Next, in step 207, when the focus lens 105 is moved in the direction of the leaf switch as the reset switch SWR while executing the counter, the counter value is 0 when passing the origin, and the counter value is 0 on the leaf switch SWR side. It becomes a negative value.

The operation of step 207 is repeated until the leaf switch SWR is closed via step 208, and when the leaf switch is closed, the driving of the focusing lens 105 is stopped in step 209.

Furthermore, in step 210, the counter value at the time when the focus lens 105 stopped in step 209 is stored in the memory 118.
to be memorized. The counter has been set to a predetermined value in step 206, and the front lens adjustment has been completed, so when the focus lens 105 reaches the origin, the counter value is set to 05, and when the leaf switch SWR is reached, the leaf switch changes from the origin. The distance to is shown as a negative value.

Therefore, when resetting the counter next time, the focus lens 105 is moved toward the leaf switch SWR until the leaf switch SWR is closed, and when it is closed, the stored value is assigned to the counter, and the focus lens 105 is moved to the side opposite to the leaf switch SWR. The point where the counter becomes O is the origin. This situation is shown in the flowchart of FIG.

In FIG. 3, 301 is a step indicating the start of program execution, 302 is a step of determining whether the power is turned on, 303 is a step of moving the focus lens 105 to the reset switch SWR side, and 304 is a reset switch SWR 305 is a step of stopping the focus lens 105. 306 is a step of reading a stored value corresponding to the distance 114 from the memory 118. 307 is a step of reading out a stored value corresponding to the distance 114 from the memory 118. 308 is a step of moving the focus lens 105 to the close side; 309 is a step of determining whether the value of the counter is within the normal operating range 117 that allows the focus lens to follow the zoom lens 102; A step of determining, 310, is a step of performing normal photographing, and 311 is a block indicating the end of execution of the step.

Therefore, when execution of the program is announced in step 301, the process waits until the power is turned on in step 302. When the power is turned on, the focus lens 105 is reset in step 303. Move the switch to the SWR side, that is, to the end side. Reset switch SW
Step 30 moves the focus lens 105 to the R side.
The process continues until it is determined in step 4 that the reset switch SWR is closed, and when the reset switch SWR is closed, the focus lens 105 is stopped in step 305.

At this point, in step 306, the stored value corresponding to the distance 114 is read out and substituted into the position detection counter of the focus lens 105. After that, while continuing to count, reset the focus lens 105 with the switch S.
Drive to the closest side in the direction away from the WR, step 309
to confirm that the counter value is within the normal operating range of 117. In other words, when the counter value reaches O, 31
0 enters normal operation.

Even if the reset switch SWR is assembled into a lens unit without adjusting the position of the reset switch SWR using the control operations described above, its installation can be done accurately by storing information on the distance between the position and the origin where the normal operating area starts in memory. The origin shown in FIG. 8 can be set within the movement area of the focus lens 105.

In this embodiment, the case where the reset switch SWR is on the negative side from the origin in terms of the value of the counter has been described. However, even when the reset switch SWR is on the positive side from the origin, the focus lens 105 can be It is clear that the coordinates of the characteristic curve of FIG. 8 can be precisely fixed within the movement range of .

In addition, in this example, the subject was focused at the wide end and a predetermined value was assigned to the position detection counter of the focus lens, but there is no problem even if the same operation is performed at the tele end, and in the manufacturing process and adjustment process. It can be selected as appropriate.

FIG. 4 shows a second embodiment having features of the present invention,
Components having the same functions as those in FIG. 1 are given the same numbers. In FIG. 4, 401 is a non-contact switch equipped with a light emitting sensor section and a light receiving sensor section facing each other, and by moving the light shielding plate 402 between the light emitting sensor and the light receiving sensor in the optical axis direction, The gate of the light receiving section is opened and closed to change the output. 403 is a light shielding plate 40
2, and when the end 403 passes through the switch 401, the non-volatile memory 11 in FIG.
Writing and reading of the count value to and from 8 is executed.

Since the non-contact switch itself shown in this embodiment is well known, a detailed explanation will be omitted, and only a top view is shown in FIG. In Figure 5, 501 is switch 4
01 is a light receiving element, 502 is a phototransistor or other light receiving element, 503, 504 is a power source such as a battery,
505 is a resistor.

Writing to the nonvolatile memory 118 is basically the same as in the first embodiment. FIG. 6 shows a flowchart of the procedure for writing to 118. Steps having the same functions as those in the flowchart of FIG. 2 are given the same numbers in parentheses in FIG. In FIG. 6, 601 is a step indicating the start of program execution, and 602 to 606 are steps 2 in FIG.
Step 607 is to perform the same processing as steps 02 to 206.
a step of determining whether the block is blocked by the
608 is the focus lens 10 while counting.
608 is a program for moving the focus lens 105 to the ω side in the same manner, 6
10 is a step 605 of determining whether the output of the switch 401 (light receiving element 502) has changed, that is, whether the state has changed from light blocking to transmitting or from transmitting to light blocking;
is a step indicating the end of the program.

Therefore, when execution of the program is started in step 601, each lens and reset switch 401 are assembled in step 602, as in the first embodiment.

After the front lens adjustment is completed in step 603, step 60
Step 4: Set the zoom lens to the wide end (telephoto end) and focus on the subject at the specified subject distance. Furthermore, in step 606, a designed counter value for the in-focus position of the focusing 105 at the subject distance at the wide end (tele end) is substituted. Next, in step 607, it is determined whether or not light is currently being transmitted, and the switch 4.0
Step 602 or 609 is selected in order to move the focus lens 105 in the direction in which the end 403 of the light shielding plate 402 approaches the light shielding plate 402 (to the close side if it is transmitting, to the ω side if it is blocking) while counting. In step 610, it is determined whether the end 403 of the light shielding plate 402 has passed the switch 401 based on the change in the output of the light receiving element, and if it has not passed, the operation of step 608 or switch 609 is repeated.

When the end 403 passes the switch 401, the focus lens 105 is stopped in step 611, and the counter value at that time is stored in the memory 118 in step 612, as in the first embodiment.

By controlling as described above, the origin of the normal operating region can be accurately fixed even if the switch 401 is assembled without adjusting the position.

[Effects of the Invention] As explained above, according to the present invention, an element is provided that stores numerical values related to the position of the lens, and in actual use, the reference position for lens position measurement is set to a predetermined subject during assembly adjustment. A switch for determining the measurement reference position in the actual use state by measuring the focal position of the lens with respect to a subject placed at a distance as a reference and storing the measured value at the time of assembly adjustment in the storage element. etc., there is no need to strictly control accuracy, which has the effect of improving productivity and serviceability.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the optical control device according to the present invention, FIG. 2 is a flowchart showing a control algorithm during adjustment in the device according to the present invention, and FIG. 3 is a control algorithm during actual use in the device according to the present invention. FIG. 4 is a block diagram showing a second embodiment of the optical control device according to the present invention; FIG. 5 is a top view for explaining the focus lens reset position detection switch in FIG. 4; FIG. 6 is a flowchart for explaining the operation in the second embodiment of FIG. 4, FIG. 7 is a configuration diagram of a normal inner focus type lens system, and FIG. 8 is a zoom lens in the inner focus type lens system. FIG. 9 is a diagram showing a state where the characteristic curve of FIG. 8 is divided into a plurality of regions and a representative speed is set for each region.

Claims (3)

[Claims] (1) a driven part that moves in a predetermined direction to change its optical state; a detection means that detects the position of the driven part; a storage means that stores information regarding a reference position of the driven part; An optical control device comprising: control means for positioning the driven portion to the reference position based on the reference position information stored in the storage means and the output of the detection means. (2) a driven part that moves in a predetermined direction to change its optical state; a detection means that detects when the driven part is at a predetermined position near its reference position; and the predetermined position and the reference. A storage means for storing information indicating a relationship with a position; and a control means for positioning the driven part to the reference position based on the information stored in the storage means and the output of the detection means. An optical control device characterized by: (3) The optical control device according to claim (1) or (2), wherein the driven section is a lens that changes optical characteristics of a lens unit.