JPH0552592A - Controlling device of object - Google Patents

Abstract

PURPOSE:To obtain a controlling device of an object which enables precise controlling of movement of the object body to be controlled, along with the movement of the object body to be controlled. CONSTITUTION:Cycle time from rise to fall of detection signal A of a detection device 203 is getting shorter according as speed of a rotation ring 101 is getting faster. A micro-computer 110 calculates the cycle time in order to set forth waiting time of the fourth lens group 106 before its halt, to be longer to appropriate amount than the cycle time, and then, when the rise and fall of the detection signal A are not detected, the fourth lens group 106 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object control device for driving a controlled object according to the movement of the measured object.

[0002]

2. Description of the Related Art Generally, when detecting a position change or movement of an object, the position change or movement of the object can be detected by, for example, irradiating the object with light and photoelectrically converting the reflected light. FIG. 6 shows the measuring method, and FIG. 7 shows the detection signal. As shown in FIG. 6, on the object to be measured (not shown), the reflection plates 301a to 301d have a predetermined pitch P.
The reflectors 301a to 301d are attached at equal intervals by
Have the same length in the moving direction of the measured object (left and right directions L and R in the drawing). The detection devices 302 and 303 have a light emitting portion and a light receiving portion, and are configured to irradiate the reflection plates 301a to 301d with light and output detection signals B and A of reflected light. Here, the detection devices 302 and 303 are the reflector 3
It is fixed with a predetermined phase difference with respect to the pitch P of 01a to 301d.

FIG. 7 shows, by way of example, reflectors 301a to 30a.
The length of 1d in the moving direction is P / 2, and the detection device 30
The detection signal A when the distance of 2,303 is 5P / 4,
B is shown. When the detection device 303 detects the reflected light from the reflection plate 301c and the detection signal A is at a high level, the reflection plate 3
01a to 301d move to the left L and the detection device 302
When the state where the reflected light from the reflection plate 301b is not detected is detected, the detection signal B changes from the low level to the high level, while the reflection plates 301a to 301 are detected.
d moves in the right direction R, and the detection device 302 moves the reflection plate 301.
When the state where the reflected light b is detected is changed to the state where it is not detected, the detection signal B changes from the high level to the low level.

Therefore, as shown in FIG.
When 01a to 301d are moved in the left and right directions L and R, the other detection signal B with reference to the detection signal A becomes signals BL and BR having different phases. For example, when the detection signal A tends to rise or fall. When the detection signal B detects a high level or a low level, the reflection plate 301
It is possible to detect the moving direction of the measured object to which a to 301d are attached. Further, the moving speed of the measured object can be detected by measuring, for example, the period from the rising edge to the falling edge of the detection signal A or B.

Since the moving direction and speed of the measured object can be measured, the reflectors 301a to 301d are used as command generators for other controlled objects, and the moving direction and speed of the controlled object are measured. Can be controlled. For example, in an inner focus type lens system, it is possible to detect the position of an electronic ring that moves a variable power lens as an object to be measured, and move the lens that corrects the movement of the focal plane as the object to be controlled.

As described above, when the movement of another object is controlled by the movement of the measured object, the following method is known. First, the rising timing of the detection signal A is used as a trigger to capture the level of the detection signal B at that time, and the falling timing of the detection signal A is used as a trigger to capture the level of the detection signal B at that time. And FIG.
As shown in, the moving direction of the object to be measured is discriminated by the levels of the detection signal B at the rising and falling edges of the detection signal A.

Next, the time T from the rise to the fall of the detection signal A is measured, and the drive speed of the controlled object is determined so as to be substantially inversely proportional to the time T, for example. And
When the level of the detection signal A does not change for a predetermined time, it is considered that the measured object has stopped, and the controlled object is stopped.

[0008]

However, in the above-mentioned conventional object control device, since it is considered that the object to be measured is stopped only when the level of the detection signal A does not change for a predetermined time, the following problems occur. There is. First, when the object to be measured moves at a relatively high speed and stops, it cannot be considered that the object to be stopped has stopped for a predetermined time. Therefore, there is a problem that the controlled object goes over the corresponding position.

Secondly, as for the input / output characteristics of the detection devices 302 and 303, as shown in FIG. 9, the output signals A and B have a finite delay with respect to the change of the input light quantity. Therefore, FIG.
As shown in, when the light quantity of the light receiving part changes in a fast cycle, the output signals A and B cannot follow this change, and the peak value gradually decreases and its rise, fall, level, etc. It will not be possible to accurately determine. In this case, since the control circuit malfunctions and the controlled object cannot be controlled accurately, in order to avoid such a malfunction of the control circuit, for example, the controlled object is stopped or the detection signals A and B are detected. However, the processing is delayed when the waiting time when the detection signal A does not change is set to be constant.

Further, in order to solve the above first and second problems, when the waiting time when the detection signal A does not change is set to be short, if the object to be measured moves at a relatively low speed, The controlled object is repeatedly driven and stopped, and the movement of the controlled object is jerky.

In view of the above-mentioned conventional problems, it is an object of the present invention to provide an object control device capable of accurately controlling the movement of a controlled object according to the movement of the measured object.

[0012]

In order to achieve the above object, the present invention has a plurality of detecting means whose output state changes periodically with the movement of the object to be measured. Of the above, in the object control device provided with the displacement measuring means, the phase of the output signal of the other detecting means with respect to the phase of the output signal of the predetermined reference detecting means is switched with regularity depending on the moving direction of the measured object, First means for obtaining the cycle of the state change of the output signal of the reference detecting means, second means for setting a first time associated with the cycle obtained by the first means, and the reference detecting means Means for measuring a second time from a time point when the state of the output signal of the device changes, and a second means set by the second means.
Of the second time measured by the third means, and the second time of the fourth time.
And a fifth means for determining that the moving state of the measured object has changed when the time coincides with or exceeds the time.

The second means sets the first time to a long time when the cycle obtained by the first means is short.

[0014]

According to the present invention, the waiting time (first time) is set shorter as the moving speed of the object to be measured is increased by the above construction, and the change state of the signal of the reference detecting means is not detected during this waiting time. In this case, it is determined that the moving state of the measured object has changed, and the controlled object stops, for example. Therefore, when the moving speed of the measured object is slow, the waiting time for stopping the controlled object is long, so that the controlled object moves smoothly without repeating driving and stopping, and the overshoot amount does not increase. Further, when the moving speed of the measured object is high, the waiting time until the controlled object is stopped is short, and therefore the overshoot amount of the controlled object does not increase. Furthermore, when the moving speed of the object to be measured is extremely high as shown in FIG. 10, the waiting time is sufficiently short to reach this state, so this state is detected in a short time and the controlled object is detected. You can stop.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a schematic configuration of a lens system to which an embodiment of an object control device according to the present invention is applied, FIG.
3 is a graph showing the relationship between the detection signal period of the detection device of FIG. 1 and the driving speed of the fourth lens group, and FIG. 3 is the detection signal period of the detection device of FIG. 1 and the fourth lens group is stopped. FIG. 4 is a graph showing the relationship with the waiting time before the operation, FIG. 4 is an explanatory view showing the relationship of FIG. 3, and FIG. 5 is a flow chart for explaining the operation of the lens system of FIG. In FIG. 1, the same components as those shown in FIG. 6 are designated by the same reference numerals.

In FIG. 1, this lens system is an inner focus type lens system used in, for example, a video camera, and has a fixed lens group 102 in a lens barrel 100 and an optical axis for changing the magnification. Has a second lens group 103 that can move in any direction, a diaphragm 104, a fixed lens group 105, a focus adjustment function, and a so-called competition function that corrects the movement of the focal plane due to zooming of the second lens group 103. It has a fourth lens group 106, and the fourth lens group 106 can be moved in the optical axis direction by an actuator (motor M) 112. Incidentally, these optical systems 102-
The image formed by 106 is picked up by, for example, a CCD on the image pickup surface 107.

A rotating ring 101 for driving the second lens group 103 is fitted in the lens barrel 100, and the rotating ring 101 has a plurality of reflections along its circumferential direction as shown in FIG. The plates 301 are attached at the same pitch P. Further, as in the case shown in FIG. 6, the detection devices 302 and 303 have a light emitting portion and a light receiving portion, and are configured to irradiate the reflecting plate 301 with light and output detection signals B and A of reflected light. ing.

The detection devices 302 and 303 are supplied with light emission power from the power amplification circuits 108 and 109, respectively.
The power amplifier circuits 108 and 109 are controlled by a microcomputer (μ-com) 110. Detection device 30
The detection signals B and A of Nos. 2 and 303 are captured by the microcomputer 110, and
Controls the motor drive circuit 111 to rotate the motor 112 and move the fourth lens group 106 in the optical axis direction to automatically adjust the movement of the focal plane. The microcomputer 110 is preset with a threshold value for determining the levels of the detection signals B and A, and is also provided with a timer for measuring time.

As shown in FIG. 2, the microcomputer 110 also has a fourth lens as the period Tsel from the rise to the fall of the detection signal A becomes shorter, that is, the speed of the rotating ring 101 becomes faster. A table is set in advance so that the driving speed V of the group 106 is increased. In this case, the driving speed V is the cycle T
When it is set so as to be completely inversely proportional to sel, the driving speed V diverges as the cycle Tsel approaches “0”, and when the cycle Tsel is very large, the driving speed V does not become “0”. Therefore, the period Tsel
The driving speed V is suppressed to a predetermined value when the driving speed V is reduced to a certain value, and the driving speed V is set to "0" when the period Tsel is increased to a certain value. When the period Tsel is between these two values, the driving speed V
Is set to be smooth without giving a feeling of strangeness in operation.

As shown in FIGS. 3 and 4, the microcomputer 110 is further preset with a waiting time Sjdg0 which is longer than the period Tsel from the rising to the falling of the detection signal A by an appropriate time. Standby time Sjdg0
Is the time until the fourth lens group 106 is stopped when the change of the detection signal A, that is, the rising and falling edges are not detected. Therefore, as the period Tsel becomes longer, that is, the speed of the rotating ring 101 becomes slower. The longer it gets.

Next, referring to FIG. 5, the operation of the above embodiment,
In particular, the operation of the microcomputer 110 will be described. Start executing this program in step 201,
In step 202, it is determined whether the detection signal A of the detection device 303 has risen. When the detection signal A rises, the process branches to step 203 and subsequent steps, and the detection signal A
The detection signal B of the detection device 302 when the
Of the timer value TA when the detection signal A rises in step 204.
Is stored, and the process returns to step 202.

If the detection signal A does not rise, the routine proceeds to step 205, where it is determined whether or not the detection signal A has fallen. When the detection signal A falls, the process branches to step 209, the level state BD of the detection signal B of the detection device 302 when the detection signal A falls is stored, and the detection signal A rises in step 210. The timer value TD when the value falls is stored. In the following step 211, the level B of the detection signal B of the detection device 302 when the detection signal A rises and when it falls.
U and BD are compared, and when BU = BD, it is considered that chattering has occurred in the detection signal A, and the fourth lens group 1
06 is stopped (step 208), and the process returns to step 202.

On the other hand, if BU ≠ BD in step 211, first, in step 212, the timer value T
The difference between A and TB is calculated to calculate the cycle Tsel of the detection signal A, and then, in step 3, the driving speed V of the fourth lens group 106 is determined by this cycle Tsel according to the curve shown in FIG. .. Then, in step 214,
Standby time Sjd for stopping the fourth lens group 106
g0 is selected according to the curve shown in FIG. 3, and this waiting time Sjdg0 is set in the counter area S in step 215.
It is set to jdg and this waiting time Sjdg0 is refreshed.

Next, at step 216, the detection signal A
Depending on the level BU of the detection signal B at the time of rising, the rotating direction of the rotating ring 101, that is, the left direction (step 2
17) or the clockwise direction (step 218),
The fourth lens group 106 is moved in the close-up direction or the ∞ direction according to the discriminating direction. The drive speed V is the speed selected in step 213.

On the other hand, when the detection signal A does not rise in step 202 and does not fall in step 205, it is one of the following three cases.
The rotating ring 101 is stopped. Rotating ring 101
Is rotating at super high speed. This is during the period when the rotating ring 101 is rotating and the detection signal A rises to falls. Therefore, in step 206, the counter Sjdg
Is decremented by one, and it is determined in step 207 whether Sjdg is "0". As a result, if Sjdg is not "0", it is not possible to determine which of the above three cases, so the process returns from step 207 to step 202 and this processing is repeated. Then, when the counter Sjdg becomes "0", which is the above or the case, the routine proceeds from step 207 to step 208, and the fourth lens group 106 is stopped.

According to the above embodiment, as shown in FIG. 4, the waiting time Sjdg0 until the fourth lens group 106 is stopped.
Is set to be longer than the period Tsel by an appropriate time, and by setting in this way, when the period Tsel is substantially equal, it is between the rising and falling of the detection signal A. It is possible to drive the fourth lens group 106 smoothly without stopping the fourth lens group 106. On the other hand, when the counter Sjdg becomes "0", the fourth lens group 106 is stopped, so that a quick stop response of the fourth lens group 106 can be realized.

That is, when the rotating ring 101 is slowly rotating, the waiting time Sjdg0 is long, so that the jerking of repeating driving and stopping of the fourth lens group 106 as in the conventional example is eliminated and smooth driving is performed. can do. In this case, since the fourth lens group 106 is slowly moving, the overshoot amount does not increase even if the waiting time Sjdg0 is long. On the other hand, when the rotating ring 101 is rotating at a high speed, the waiting time Sjdg0 is short, and therefore the overshoot amount of the fourth lens group 106 does not increase.

Considering the case where the rotating ring 101 rotates at an extremely high speed and the detection signal A is rounded as shown in FIG. 10, the rotating ring 101 makes a sudden transition from the stopped state to the high speed state. Instead, the rotation speed increases in a short time, so the waiting time Sjdg0 is set short. Therefore, even if the rising and falling edges of the detection signal A cannot be detected in the ultra-high speed state, the fourth lens group 106 can be stopped in a short time. Here, when the rotating ring 101 is manually rotated, uneven rotation occurs,
By setting the standby time Sjdg0 to be several times longer than the cycle Tsel in advance, it is possible to prevent the stop response from becoming too sensitive.

[0029]

As described above, the present invention has a plurality of detecting means whose output state changes periodically with the movement of the object to be measured. In the object control device provided with the displacement measuring means in which the phase of the output signal of the other detecting means with respect to the phase of the output signal of the reference detecting means is changed regularly with the moving direction of the measured object, First means for determining the cycle of the state change of the output signal, second means for setting a first time associated with the cycle determined by the first means, and status of the output signal of the reference detecting means. Changes from the point of change as the starting point to measure the second time, the second time set by the second means, and the third time.
Fourth comparing the second time measured by the means of
And the fifth means for determining that the moving state of the measured object has changed when the second time coincides with or exceeds the fourth time, the movement of the measured object Accordingly, the movement of the controlled object can be controlled accurately.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a lens system to which an embodiment of an object control device according to the present invention is applied.

FIG. 2 is a graph showing a relationship between a cycle of a detection signal of the detection device of FIG. 1 and a driving speed of a fourth lens group.

FIG. 3 is a graph showing a relationship between a cycle of a detection signal of the detection device of FIG. 1 and a waiting time until the fourth lens group is stopped.

FIG. 4 is an explanatory diagram showing the relationship of FIG.

5 is a flow chart for explaining the operation of the lens system of FIG.

6 is an explanatory diagram showing the detection device of FIG. 1. FIG.

7 is a timing chart showing a detection signal in FIG.

FIG. 8 is an explanatory diagram showing a movement direction determination operation based on the detection signal of FIG. 7;

9 is a waveform diagram showing input / output signals of the detection device of FIG.

10 is a waveform diagram showing input / output signals of the detection device when the rotating ring of FIG. 1 is fast.

[Explanation of symbols]

 101 rotating ring 106 fourth lens group 110 microcomputer 301 reflectors 302, 303 detection device

Claims (3)

[Claims] 1. A plurality of detecting means, the output state of which changes cyclically with the movement of the object to be measured, the other detecting means having a phase relative to an output signal of a predetermined reference detecting means. In the object control device provided with the displacement measuring means in which the phase of the output signal of the detecting means has a regularity depending on the moving direction of the object to be measured, the cycle of state change of the output signal of the reference detecting means is obtained. 1 means and the first
The second means for setting the first time associated with the cycle obtained by the means for measuring the second time and the third means for measuring the second time from the time when the state of the output signal of the reference detecting means changes as a starting point. Means, fourth means for comparing the second time set by the second means with the second time measured by the third means, and the second time for the fourth time. And a fifth means for determining that the moving state of the object to be measured has changed when the time coincides with or exceeds the time. 2. The object control device according to claim 1, wherein the second means sets the first time to a long time when the cycle obtained by the first means is short. 3. The object control device according to claim 1, wherein the first time period is longer than the cycle of the output signal of the reference detection means.