JP2974371B2 - Drive control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device suitable for use in a camera lens control device and the like.

[Related Art] In recent years, video equipment such as a video camera, an electronic still camera, and a camera-integrated VTR have been remarkably developed, and in particular, functions and operability have been enhanced, and reduction in size and weight has been achieved. Above all, with the rapid spread of camera-integrated VTRs,
A significant reduction in size and weight has been achieved by reducing the number of parts and changing the structure itself.

By the way, taking a camera-integrated VTR as an example, a lens unit requires a relatively large space and components.

FIG. 6 shows an example of a so-called inner focus type structure, in which the front lens is fixed, and the rear lens group performs zooming and focus adjustment, thereby making it possible to reduce the size of the lens group. It is known as a configuration.

In the figure, 101 is a fixed front lens, 102 is a variable power lens (zoom lens), 103 is a stop, 104 is a fixed third lens unit, and 105 is a function of correcting the movement of the focal plane due to the movement of the zoom lens. This is a fourth lens unit (focus lens) having both a (compensator function) and a focus function.

When zooming is performed by moving the zoom lens in the lens system configured as shown in FIG. 6, the fourth group lens performs an operation having both a compensator function and a focusing function as described above. This is shown in FIG.

FIG. 7 shows the positional relationship between the zoom lens and the focus lens using the object distance as a parameter, with the horizontal axis representing the zoom lens position and the vertical axis representing the focus lens position. As is clear from the figure, during the zoom operation, the focus lens can perform the zoom operation in focus without any blur if it moves along a specific locus with respect to each subject distance. If it deviates from the trajectory, blur will occur.

A method of moving the focus lens according to a specific trajectory according to the subject distance during the zoom operation has been proposed in, for example, Japanese Patent Application Laid-Open No. 1-280709. In this method, the locus of FIG. 7 is divided into regions having substantially equal inclinations as shown in FIG. 8, and one speed is given to each region as a representative speed. During the zoom operation, the positions of the zoom lens and the focus lens are changed. One of the regions is determined by the relationship, so that when there is a lens in that region, the focus lens is moved at the representative speed of that region.

However, in the above method, the representative speed of each area is
Since it is determined for one zoom lens moving speed, if the zoom lens moving speed fluctuates due to, for example, a variation in zoom motor, a temperature difference, or a posture difference due to a camera angle or the like, the locus in FIG. 7 will not be correctly followed. There was a problem.

On the other hand, for example, JP-A-1-319717 proposes a method of adjusting a focus lens driving speed during a zoom operation by adjusting a coefficient by which the representative speed is multiplied according to a change in an actual zoom speed. I have.

For example, the horizontal axis in FIG. 8 is divided into 16 equal parts. Now the zoom speed is designed at tele end (T) wide end (W)
If the speed is set to move in 7 seconds, the third
As shown in the figure, when passing through one zoom zone 301, NTS
In the case of the C method, 26 vertical synchronization periods (26 VSymc) are required. In the actual zoom operation, N [Vsym
c], the reference value of the zoom speed (TW 7
sec), the ratio R _ZS can be expressed by R _ZS = N / 26 (1). Therefore, during the zoom operation, the vertical synchronization period required to pass through the one zone is always measured, and 1 /
By multiplying the R _ZS in the representative speed, it becomes possible to perform the zooming at the moving speed of the focus lens in response to changes in the zoom speed without causing blur.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, since the measurement of the zoom speed and the calculation of the formula (1) are performed by the microcomputer, there are the following disadvantages.

If the measured values and calculation results are stored in a volatile memory such as RAM, the data will be lost when the power is turned off and cannot be used for subsequent control.

Even if data is stored in a non-volatile memory such as E ² PROM to compensate for the drawback of the above, the zoom speed may not be used for a long time, Is changed, the zoom operation starts at the wrong focus lens driving speed.

In connection with the problem of data loss, power
When the zoom operation is performed for the first time after being turned on, the zoom operation may start at a completely different focus lens speed without corresponding to the zoom operation until a stable measured value N is obtained.

Means for Solving the Problems The present invention has been made for the purpose of solving the above-mentioned problems, and the feature of the present invention is that the first lens and the movement of the first lens are provided. On the other hand, a second lens driven to follow based on predetermined characteristics, speed detecting means for detecting a driving speed of the first lens, and a detection result of the speed detecting means according to power supply. And a control unit for calculating and determining the drive speed of the second lens based on the drive speed.

Another feature of the present invention is that the first lens and the first lens
Measuring means for measuring the moving speed of the second lens, and the second means based on a predetermined relationship to the movement of the first lens.
And a driving unit that changes the moving speed of the second lens with respect to the driving speed of the first lens, based on a measurement result of the measuring unit according to power supply. A drive control device including: a calculating unit that determines a moving speed of the second lens; and a storing unit that stores a position of the first lens before the measuring of the moving speed of the first lens by the measuring unit. is there.

[Embodiment] An embodiment of a drive control device according to the present invention will be described below in detail with reference to the drawings.

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

In the figure, 101, 102, 103, 104 and 105 are elements of the optical system having the same functions as in FIG. 106, 107 and 108 are zoom lens 102, aperture 103 and focus lens 10, respectively.
Actuators 109, 110, 111, for example, by motors for driving 5 are actuators 106, 107, 108, respectively.
Drivers 112 and 113 are position encoders for detecting the positions of the zoom lens 102 and the focus lens 105, respectively, and 114 is an image sensor such as a CCD for converting an image formed by the lens into a video signal and outputting it. , 115 is an amplifier for amplifying the output signal of the image sensor 114, 11
6 is a band-pass filter that extracts only high-frequency components effective for detecting the focus state among the output signals of the amplifier 115,
117 performs focusing by moving the focus lens 105 in a direction in which the high-frequency component increases according to the output signal of the band-pass filter 116, or as described in the conventional example,
A lens drive control microcomputer 118 controls the zoom operation by moving the zoom lens 102 and the focus lens 105 at the same time. 118 measures the brightness of the subject based on the luminance level of the output signal of the amplifier 115, and opens the aperture 103. This is a diaphragm control device that keeps the brightness constant by adjusting the amount.

FIG. 2 shows a flowchart of an operation control program stored in the lens drive control circuit 117 for operating the control device according to the present invention.

In the figure, reference numeral 201 denotes a step indicating the start of a control program, 202 denotes a step of determining whether power is turned on, 203
Is the value of the zoom encoder 112, that is, the zoom lens 102
Reading a moving position of 204 horizontal axis step 205 that the zoom lens 102 from the value of Z _ES is divided as shown in FIG. 8 for storing the value of the zoom encoder read in step 203 in the memory as the Z _ZS calculates whether located in any region of the upper, or storing a Z _ES in the memory, 206 is a zoom lens 102 than the intermediate value Z _M of the zoom lens moving area is located to the wide side, tele It is a step of determining whether or not it is located on the side. Assuming that the zoom lens driving speed measurement section is divided into three regions in the horizontal axis direction as shown in FIG. 8, a step 207 calculates the measurement end point on the tele side from Z _ZS as Z _ZE , and 208 Step 209 is a step of resetting the value of a counter for measuring the driving speed of the zoom lens 102 to 0, 209 is a step of moving the zoom lens 102 to the tele side, and 210 is a step 20
5 a similar manner, and calculating whether the zoom lens is in which divided areas, the result storing in the memory as a Z _Z, 211 whether Z _Z exceeds or equal to Z _ZS +1, i.e. the step of the zoom lens from Z _ZS is started toward the telephoto side, beyond the start regions determines whether the entered next divided region, 212 O at step 208
Incrementing the counters reset by one,
213 step of determining whether Z _Z whether reaches the Z _ZE, ie the 3 regions were done by zooming a measurement interval, 214 step of determining whether or not the vertical synchronization signal is input, 215 is a program for stopping the zoom lens, 216 is a step for moving the zoom lens 102 in the wide direction, and 217 is a zoom lens in the same manner as in step 203.
Storing in a memory the output of the zoom encoder for detecting the read Z _E the position of 102, 218 whether i.e. zoom lens 102 Z _E falls below the Z _ES steps 203
219 is a program for calculating the measurement end area on the wide side from _ZZS for the same purpose as in step 207, and 220 is for moving the zoom lens to the wide side for the same purpose as in step 211. When moved, it is determined whether the zoom lens has entered the divided area next to _ZZS.Step 221 measures the speed when driving the zoom lens 102 to the wide side for the same purpose as in step 213 to measure the speed. Step of determining whether or not the section has been zoomed, 222
Is a step for determining whether or not the zoom position has returned to the original position for the same purpose as step 218, 223 is a program for calculating _RZS according to equation (1), and 224 is a step for ending the flow chart of FIG. . Second in step 201
When the program shown in the flowchart in the figure starts, it waits until the power is turned on in step 202. When the power is turned on, in steps 203 and 204, the current detected value Z _ES of the zoom encoder, that is, the zoom lens position is read and stored in the memory. Further obtains the divided region Z _ZS corresponding to the zoom lens position Z _ES in step 205.

Incidentally, in the measurement of the zoom speed, it is desirable to perform a zoom operation on a plurality of decomposed regions in consideration of the variation. At this time, if the measurement direction is set to one direction, there is a problem in that the end of the moving range is hit before the measurement is completed. Therefore, in step 206, the intermediate Z _M zooming movement range, the zoom lens, it is determined whether there for or the telephoto side in the wide side, to the wide side if the telephoto side, to select if the telephoto side to the wide side of the measurement direction .

If it is determined in step 206 that the zoom lens is on the wide side, first in step 207, a divided area _ZZE indicating the end of measurement is calculated.

In this embodiment, since the measurement area is set to 3, if Z _ZE is determined as in step 207, the Z _Z obtained in step 210 is obtained.
When it reaches _ZZE , it can be determined that it has passed the measurement area. Next, in step 208, the counter is reset, and in step 209, the zoom is driven toward the telephoto side.

In steps 203 and 210, it is sequentially calculated which divided area the zoom lens is in.

To accurately measure the transit time of the zoom lens in the three divided areas, step from the boundary of the area to the boundary.
You need to count at 212. However, at the stage of step 203, the zoom lens is not always on the boundary, but rather, it is more likely that the zoom lens is present in the divided area as shown by point A in FIG. Therefore, in step 211, when the zoom lens is located in the same divided area as when the zoom lens started to move, the flow returns to step 208, and the count value of the counter is not increased, and the state is maintained until the next divided area is entered. . Then, when entering the adjacent divided area, the program after step 212 is executed.

Each time step 212 is executed, the count value of the zoom mode measurement counter increases by one. After executing step 212, the position of the zoom lens is grasped in units of divided areas in steps 203 and 210, and it is determined in step 213 whether or not the lens has passed three divided areas. If it is determined in step 213 that it has not passed through the three divided areas, step 21
At step 4, the flow waits for the arrival of the vertical synchronization signal, and upon arrival, returns to step 212 to increment the count value of the counter by one. By doing so, the time required for the zoom lens to pass from the boundary between the three divided regions to the boundary can be measured as the number of vertical synchronization signals with almost no error. If it is determined in step 213 that the measurement is completed, the program after step 215 is executed to return the zoom lens to the position in step 203, and an operation for matching the angle of view at the time of power on is performed.

First, in step 215, the zoom lens is temporarily stopped.
Next, in step 216, the zoom lens is moved in the direction opposite to the above-described measurement, that is, toward the wide side as described above. Thereafter, Z _E encoder value at step 217
As in step 203, and
To determine if Z _E is equal to or less than Z _ES . If it is determined in step 218 that it has not returned to the original position, the process returns to step 216 and repeats this. If it is determined in step 218 that it has returned to the original position, zooming is stopped in step 215, an initial coefficient R _ZS is calculated in step 222 according to equation (1), multiplied by the representative speed, and the first time after the power is turned on. The start value of the focus lens speed for the zoom operation is determined.

With the above operation, the start speed of the focus lens can be determined under conditions close to the actual use condition, and the angle of view hardly changes (the zoom lens has the resolution accuracy of the zoom encoder. (Return to the original position), and it becomes possible to start shooting. The description of the present embodiment has been made on the case where the initial zoom position is on the wide side from the middle of the zoom movement area. If you are on the tele side, just move the above description symmetrically,
Since the concept is completely the same as the above description, the description is omitted.

FIG. 4 is a block diagram of a second embodiment of the lens control device according to the present invention, in which components having the same functions as those in FIG. 1 are denoted by the same reference numerals.

In FIG. 4, reference numeral 401 denotes a power supply, 402 denotes a ground potential, 403 denotes a zoom tele switch for driving the zoom lens to the tele side,
4 is a zoom wide switch for driving the zoom lens to the wide side, 405 is a resistor for a zoom tele switch, 406 is a resistor for a zoom wide switch, and 407 and 408 are 405 and 406, respectively.
Is a brush that slides. By pressing the switch 403 or 404, the potential of the brush 407 or 408 changes continuously. This potential is read by the drive control circuit 117, and the rotation speed of the actuator 106 is adjusted to change the speed at which the zoom lens 102 is moved.

FIG. 5 is a flowchart showing a control program in the drive control circuit 117 for executing the second embodiment with the configuration of FIG. 501 is a step indicating the start of a program, 502 is step 201 in FIG. 2 described in the first embodiment.
Step 503 for executing the program for performing the control operation shown in steps 224 to 224 is to set the potentials of the brushes 407 and 408 to A / D
Step brush 4 converted and taken into drive control circuit 117
Step 505 of determining whether the voltage of 07 or 408 is the zoom lens stopped state, 505 is a step of determining the zoom speed from the result of Step 503, 506 is a step of determining the speed determined in Step 505, 506 Is Step 5
Calculating the ratio of the speed determined in 05 and the standard zoom used to determine the focus lens driving speed in FIG. 8 or selecting from a memory prepared in advance, 50
7 is multiplied by the result of step 506 to R _ZS being determined at step 502, the step of changing the initial coefficient to match the given zoom speed, 508 is a step of indicating the end of execution of the control program.

When the program starts in 501, first, step 502
Then, the operation described in the first embodiment is performed to obtain _RZS .
Next, at step 503, the voltage of the zoom switch is A / D converted, and at step 504, the state is sensed. As a result, step 504
If it is determined to stop, the process returns to step 503 to repeat this. If it is determined in step 504 that the voltage of the zoom switch is at the zoom drive level, in step 505, a zoom speed corresponding to the voltage is selected. Further, in step 506, the ratio between the result of step 505 and the standard zoom speed is calculated or selected.
If _RZS is changed, the same effect as in the first embodiment can be obtained even if the camera system is provided with a variable speed zoom function.

[Effects of the Invention] As described above, according to the drive control device of the present invention, in the device for adjusting the movement speed of the second lens that follows the change in the movement speed of the first lens, the change in the movement speed of the first lens. hand,
By measuring the moving speed of the first lens in advance before actual use, after the power is turned on, the second lens can be accurately moved from the first moving of the first lens to the state of the device at that time. This makes it possible to adjust the moving speed of the lens, and to perform lens control with a stable performance without blurring and a good operational feeling.

Further, the position of the first lens before measuring the speed measurement of the first lens is stored, and after the measurement,
By returning the first lesbian to that position, there is also an effect that actual use becomes possible from the state when the power is turned on.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a drive control device according to the present invention, FIG. 2 is a flowchart showing a control operation in the first embodiment shown in FIG. 1, and FIG. FIG. 4 is a block diagram showing a second embodiment of the drive control device according to the present invention; FIG. 5 is a flowchart showing a control operation of the second embodiment of FIG. 4; FIG. 7 is a diagram showing an example of a conventional inner focus type lens structure. FIG. 7 is a characteristic diagram showing a positional relationship between a zoom lens and a focus lens using a subject distance as a parameter. FIG. 8 is a diagram showing a zoom lens position and a focus lens position. FIG. 7 is a diagram showing a state in which the relationship is divided into a plurality of regions and a representative speed of the focus lens is set for each divided region.

Claims (6)

(57) [Claims] A first lens, a second lens driven to follow the movement of the first lens based on a predetermined characteristic, and a driving speed of the first lens is detected. A drive control device comprising: speed detection means; and control means for calculating and determining a drive speed of the second lens based on a detection result of the speed detection means in accordance with power supply. . 2. A first lens, measuring means for measuring a moving speed of the first lens, and causing the second lens to follow the movement of the first lens based on a predetermined relationship. A driving unit that changes a moving speed of the second lens with respect to a driving speed of the first lens; and, based on a measurement result of the measuring unit, based on a power supply, for driving the second lens. A drive control device comprising: a calculation unit that determines a movement speed; and a storage unit that stores a position of the first lens before the measurement of the movement speed of the first lens by the measurement unit. . 3. The apparatus according to claim 2, further comprising: a unit for returning the first lens to a position stored in the storage unit after the measurement operation by the measurement unit is completed. Drive control device. 4. The method according to claim 2, wherein the driving speed of the first lens is equal to the measured moving speed when driving the first lens after measuring the moving speed of the first lens. If different, a drive control device comprising means for changing the moving speed of the second lens based on the moving speed measured by the measuring means. 5. The apparatus according to claim 2, further comprising: means for stopping the measurement operation when the first moving body moves while the measuring means measures the moving speed of the first moving body. A drive control device characterized by the above-mentioned. 6. The apparatus according to claim 2, further comprising a detecting unit configured to detect a position of the first lens before performing a measuring operation by the measuring unit, wherein the detecting unit detects the position of the first lens based on positional information obtained by the detecting unit. A drive control device configured to determine a moving direction of the first lens during operation.