JPH0486611A - Image pickup device - Google Patents

Abstract

PURPOSE:To facilitate the correction of the position of a master lens with simple constitution by correcting the position of a master lens by using a technique of interpolation computation from tracking data. CONSTITUTION:This device has means 26, 30, 36B for moving a variator lens, a means 32 which detects the position of the variator lens 4 and outputs the position detection data S3 thereof, and means 30, 36A which detect the position of the master lens 8 and output the position detection data thereof. Correction data TK is formed by subjecting the tracking data TK1 to TK5 to the interpolation computation in accordance with the position detection data S3 of the variator lens and the position detection data of the master lens and the master lens 8 is moved in accordance with the correction data TK. The constitution of a tracking data housing means 34 is simplified in this way and the constitution over the entire part is simplified.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A. Industrial field of application B. Overview of the invention C. Prior art (Figures 7 and 8) D. Problems to be solved by the invention, II (Figures 7 and 8) Ell! Means for solving (Figure 1) F action (Figure 1) G embodiment (Figures 1 to 6) (G1) First embodiment (Figures 1 to 5) (G2) Other Embodiments (FIG. 6) Effects of the Invention A Field of Industrial Application The present invention relates to an imaging device, and can be applied to, for example, a camera-integrated video tape recorder.

B. Summary of the Invention The present invention generates correction data using an interpolation calculation technique when moving a variator lens of an inner focus zoom lens to vary magnification in an imaging device.
By moving the master lens based on the correction data and preventing fluctuations in back focus, the overall configuration can be simplified.

C. PRIOR TECHNOLOGY Conventionally, the optical system of a camera-integrated video tape recorder uses a zoom lens, so that an image of a subject can be imaged by enlarging or reducing the image as necessary.

In other words, as shown in FIG. 7, in a zoom lens 1 (hereinafter referred to as a front-focus zoom lens) in which the focus is adjusted by moving the front lens, the front lens 2 placed on the subject side is indicated by an arrow. The focus is adjusted by moving it back and forth as shown by a.

Furthermore, a variator is placed at the rear of the front lens 2.
The lens 4 is moved back and forth as indicated by the arrows, thereby varying the magnification of the zoom lens 1.

Furthermore, as shown by arrow C, the compensator lens 6 is moved back and forth at the same time as the variator lens 4, thereby correcting fluctuations in back focus caused by varying magnification.

In this way, by varying the positions of the variator lens 4 and the convencator lens 6, the image of the subject formed through the master lens 8 can be enlarged or reduced.

On the other hand, as shown in FIG. 8, in a zoom lens 10 (hereinafter referred to as an inner focus zoom lens) in which the focus is adjusted by moving the master lens 8, the master lens 8 is used instead of the front lens 2. Adjust the focus by moving it forward or backward.

Further, the variator lens 4 is moved back and forth as shown by the arrow d to vary the magnification, and at the same time the master lens 8 is moved back and forth as shown by the arrow e to correct the back focus.

As a result, the inner focus zoom lens 10 can be made smaller overall than the front lens focus zoom lens 1, and can also focus on a nearby subject, making it easier to use the camera-type video tape recorder. can be improved.

D Problems to be Solved by the Invention By the way, in the zoom lens 1 with front focus, if the variator lens 4 and the compensator lens 6 are kept in a fixed positional relationship and moved, the back focus can be kept at a constant value. can.

Therefore, in the front focus zoom lens 1, a spiral groove is formed inside the lens barrel, and the variator lens 4
The zoom mechanism can be easily configured by simply configuring the compensator lens 6 to move along the groove.

On the other hand, in the inner focus zoom lens 10, depending on the distance to the subject to be focused on,
It is necessary to change the way the master lens 8 is moved relative to the variator L lens 4.

For example, when enlarging and imaging a distant object, the back focus can be maintained at a constant value by moving the variator lens 4 toward the master lens 8 side and the master lens 8 toward the variator lens 4 side.

On the other hand, when enlarging an image of a nearby subject,
The variator lens 4 is moved to the master lens 8 side, the master lens 8 is moved to the variator lens 4 side, and when the variator lens 4 approaches the master lens 8 side by a predetermined value or more, the moving direction of the master lens 8 is reversed. This makes it possible to maintain the back focus at a constant value.

Therefore, the inner focus zoom lens 10 has a problem in that it is difficult to easily construct a zoom mechanism.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose an imaging device that can easily configure an inner focus zoom lens.

E! ! Means for Solving the Problem In order to solve the problem, in the first invention, an inner focus zoom lens 22 that corrects the digit 1 of the master lens 8 according to the position of the variator lens 4 is used to obtain the desired image. In the imaging device 20 that images a subject, a variator lens moving means 26, 30, 36B that moves the variator lens 4, and a variator that detects the position of the variator lens 4 and outputs variator lens position detection data S3. A lens position detection means 32 and a master lens position detection means 3 that detects the position of the master lens 8 and outputs master lens position detection data.
0.36A and a variator for a subject at a predetermined distance.
Tracking data TKl, TK2, TK3, TK4, TK5 representing the positional relationship between the lens 4 and the master lens 8
and tracking data TKI, based on the variator lens position detection data S3 and the master lens position detection data.
The control means 30 generates correction data TK by interpolating TK2, TK3, TK4, and TK5, and moves the master lens 8 based on the correction data TK.

Furthermore, in the second invention, in an imaging apparatus 20 that images a desired subject using an inner focus zoom lens 22 that corrects the position of the master lens 8 according to the position of the variator lens 4, the variator lens 4 Variator-lens moving means for moving 26.3
0.36B and the position of the variator lens 4 is detected,
Variator lens position detection means 32 that outputs variator lens position detection data S3, and master lens 8
master lens position detection means 30.36A that detects the position of the variator lens 4 and outputs master lens position detection data, and tracking data TKI that represents the positional relationship between the variator lens 4 and the master lens 8 with respect to a subject at a predetermined distance.
, TK2, TK3, TK4, TK5, and tracking data TKI, TK2, TK3, T based on the variator lens position detection data S3 and the master lens position detection data.
Interpolate K4 and TK5 to generate correction data TK,
and a control means 30 that moves the master lens 8 based on the correction data TK, and the control means 30 is configured such that the variator-lens moving means 26, 30, and 36B move the variator lens 8.
When the variator lens position detection data S3 does not change even though the lens 4 has been moved, the variator
Detect the moving direction of the lens 4, and based on the detection result,
The value of the variator lens position detection data S3 is corrected to generate correction data.

Based on F action variator lens position detection data S3 and master lens position detection data, tracking data T
By interpolating KI, TK2, TK3, TK4, and TK5 to generate correction data TK and moving the master lens 8 based on the correction data TK, the configuration of the tracking data storage means 34 can be simplified. Therefore, the overall configuration can be simplified accordingly.

Furthermore, at this time, when the variator lens position detection data S3 does not change even though the variator lens 4 is moved, the moving direction of the variator lens 4 is detected, and the variator lens position is detected based on the detection result. If the value of data S3 is corrected to generate correction data,
Even when the resolution of the variator lens position detection data S3 is coarse, the master lens 8 can be moved smoothly, and the configuration of the variator lens position detection means 32 can be simplified accordingly.

G example An embodiment of the present invention will be described in detail below with reference to the drawings.

(G1) First Embodiment In FIG. 1, in which parts corresponding to those in FIG. The image sensor 24 captures an image of the subject.

The drive motors 26 and 28 are pulse motors that move the variator lens 4 and the master lens 8 in response to control signals 31 and S2, respectively, and thereby switch the magnification of the zoom lens 22 and adjust the focus. There is.

The analog-to-digital conversion circuit (A/D) 32 converts the output signal of the encoder attached to the variator lens 4 into a digital signal.
Lens position detection data S3 is generated and output to the control circuit 30.

This allows the analog-to-digital conversion circuit 32 to detect the position of the variator lens 4 based on the variator lens position detection data S3.

The memory circuit 34 is configured to store tracking data, and by moving the master lens 8 based on the tracking data, it is possible to correct fluctuations in back focus due to changes in magnification.

As shown in FIG. 2, the tracking data is data representing the positional relationship between the variator lens 4 and the master lens 8, and when the variator lens 4 is moved while focusing on a subject at a predetermined distance, It is designed to represent the position of the master lens 8 that can correct back focus fluctuations.

Further, at this time, in the tracking data, the position of the variator lens 4 is represented by the variator lens position detection data S3, whereas the position of the master lens 8 is represented by the number of pulses of the drive motor 26.

Furthermore, in this embodiment, the memory circuit 34 has a curve TKI
As shown by TK5, five types of tracking data are stored depending on the distance to the subject.

As shown in FIG. 3, when the power of the camera-integrated video tape recorder 20 is turned on, the control circuit 30 moves from step SPI to step SP2, and moves the master lens 8 to the initial position closest to the image plane. let

Subsequently, the control circuit 30 moves to step SP3, detects the position of the variator lens 4 based on the variator lens position detection data S3, and then moves to step SP4.

Here, when the focus adjustment operator 36A is turned on, a control signal S2 is sent to the drive motor 28 according to the amount of operation.
is output and the master lens 8 is moved.

Thereby, focus adjustment can be performed on a subject desired by the user.

Furthermore, at this time, in the control circuit 30, the drive motor 2
The position of the master lens 8 is detected by counting the number of pulses of the control signal S2 outputted to the master lens 8.

Subsequently, the control circuit 30 moves to step SP5 and detects the position of the track from the tracking data.

In other words, the position detection results of the variator lens 4 and the master lens 8 are represented by a curve TK as tracking data.
If the variator lens 4 and the master lens 8 are moved along the tracks TK1 to TK5 when located on any of the tracks TK1 to TK5 (hereinafter referred to as tracks),
It is possible to vary the magnification while preventing fluctuations in back focus.

Therefore, if tracking data is stored in the memory circuit 34 in advance for all possible positions of the variator lens 4 and the master lens 8, the magnification can be easily adjusted based on the tracking data.

However, if this is done, the size of the memory circuit 34 will inevitably increase.

Therefore, in this embodiment, five types of tracking data are stored in the memory circuit 34, and the remaining tracking data is generated from the tracking data using an interpolation calculation method.

That is, the control circuit 30 determines between which tracks (in this case, tracks TK4 and TK5) the intersection point O of the position detection results A and P of the variator lens 4 and master lens 8 is based on the tracking data stored in the memory circuit 34. Detect whether it is located at

Further, the control circuit 30 generates position data P (
K) and P(K±1) are detected.

As a result, the control circuit 30 obtains the position data P1 and P2 of the following formula % formula % (1), and obtains the position data P1 and P2 of the upper track TK4.
is stored in the register circuit along with identification data.

On the other hand, when the position detection results of the variator lens 4 and the master lens 8 are located on the tracks TKI to TK5, the position data P (K) and P of the tracks TKI to TK5 and the tracks TK2 to TK5 below it (K+1)
Based on the position data P1 and P of equations (1) and (2)
2 is obtained and stored together with the identification data of track TK4.

Subsequently, the control circuit 30 moves to step SP6 and determines whether the zoom operator 36B has been turned on. If a negative result is obtained here, step SP6 is repeated.

On the other hand, when the zoom operator 36B is turned on, an affirmative result is obtained, and the control circuit 30 moves to step SP7, outputs a control signal S1 to the drive motor 26 according to the operation amount, and controls the variator. - Move the position of the lens 4.

This allows the user to enlarge or reduce the image of a desired subject.

Next, the control circuit 30 moves to step SP8, detects the value of the variator-lens position detection data S3, and then determines whether the value of the variator-lens position detection data S3 has changed.

If a negative result is obtained here, the control circuit 30 moves to step SP9 and drives the master lens 8.

That is, the control circuit 30 detects a value N that internally divides the tracks TK4 and TK5 expressed by the following equation from the position data PI and P2.

Further, the control circuit 30 accesses the tracking data stored in the memory circuit 34 based on the identification data of the track TK4 and the value A1 of the variator-lens position detection data S3, and thereby tracks TK4 and TK5 corresponding to the value A1. Position data P (K)1, P (K
+1) Detects 1.

Furthermore, the control circuit 30 controls the position data P(K)1, P
After detecting the position data of a value P1 that is obtained by internally dividing (K+1)1 by the value N, the master lens 8 is moved based on the position data P1.

As a result, the master lens 8 can be moved along a virtual track TK that internally divides the tracks TK4 and TK5 based on the initially detected positional relationship between the variator lens 4 and the master lens 8, thereby simplifying the configuration. An inner focus zoom mechanism can be configured with this.

The control circuit 30 then proceeds to step 5P10, and determines whether the zoom operator 36B is still turned on. If a positive result is obtained here, the control circuit 30 returns to step SP6. As a result, the control circuit 30 Steps 5P7-3P8- are performed during the period in which the zoom operator 36B is turned on.
Repeating the loop of 3P9-3P 10-3P7, the master lens 8 is sequentially moved as the variator lens 4 moves.
The magnification of the zoom lens 22 can be varied by correcting the position of the zoom lens 22, thus preventing fluctuations in the back focus.

On the other hand, if a negative result is obtained in step SP''8, the control circuit 30 moves to step 5PII, where it corrects the value of the variator-lens position detection data S3.

That is, when correcting the position of the master lens 8 based on the value of the variator-lens position detection data S3 output from the analog-to-digital conversion circuit 32 in this way,
If the resolution of the variator lens position detection data S3 is coarse, as shown in FIG. 4, the master lens 8 will be moved intermittently with respect to the movement of the variator lens 4.

Therefore, in a captured image, focusing and defocusing are repeated, and the image quality changes unnaturally, making it unsightly.

Therefore, in this embodiment, steps 5P7-3P
8-3P9-3P When repeating the loop of 10-3P7, if the value of the variator lens position detection data S3 does not change in step SP8 even though the zoom operator 36B is turned on, step Moving to 5PII, the value of the detected variator lens position detection data S3 is corrected.

That is, as shown in FIG. 5, the control circuit 30 takes in the variator lens position detection data 33 (FIG. 5 (A)) at a predetermined period T (FIG. 5 (B)), and receives the variator lens position detection data S3. The value of A (N-1), A (N)
, A (N+1), . . . do not change, the value A is determined based on the moving direction of the variator lens 4.
(N-1), A (N), A (N+1), ...
・The following values A (N), A (N+1), ...
・Detect.

Furthermore, the control circuit 30 executes the arithmetic processing of the following formula (%) to obtain the average value of the continuous values, and generates the correction data DH (FIG. 5(C)).

If the value does not change two more times in a row, the control circuit 30
obtains the average value of the value of equation (4) and the following values, and generates correction data DH.

After generating the correction data D)I, the control circuit 30 moves to step SP9 and corrects the position of the master lens 8 based on the correction data 9DH, thereby effectively avoiding unnatural changes in image quality. You can zoom smoothly.

Therefore, the analog-to-digital conversion circuit 32 with a simpler configuration can be used, and the overall configuration can be simplified.

On the other hand, if the zoom operator 36B is not turned on, a negative result is obtained in step 5PIO, and the process moves to step 5PI2 to end the processing procedure.

Thus, in this embodiment, the drive motor 26, the control circuit 30, and the operator 36B constitute a variator-lens moving means for moving the variator-lens 4, whereas the analog-to-digital conversion circuit 32 moves the variator-lens 4. A variator-lens position detection means is configured to detect the position and output variator-lens position detection data S3.

On the other hand, the control circuit 30 and the operator 36A constitute a master lens position detection means that detects the position of the master lens 8 and outputs master lens position detection data, whereas the memory circuit 34 constitutes a master lens position detection means that detects the position of the master lens 8 and outputs master lens position detection data. Tracking data TKI, TK2, TK3, T representing the positional relationship of the variator lens 4 and master lens 8 with respect to the subject
A tracking data storage means for storing K4 and TK5 is configured.

Furthermore, the control circuit 30 generates tracking data TKI, TK2, TK3, TK4 based on the variator lens position detection data S3 and the master lens position detection data.
, TK5 to generate correction data TK and to move the master lens 8 based on the correction data TK.

In the above configuration, when the power of the camera-integrated video tape recorder 20 is turned on, the master lens 8 moves to the initial position in the immediate vicinity of the imaging surface, and then moves to the user's desired position in response to the operation of the operator 36A. Move to position.

This allows the control circuit 30 to detect the set position of the master lens 8.

On the other hand, when the zoom operator 36B is turned on, the variator lens 4 moves to a position desired by the user in response to the operation.

At this time, in the control circuit 30, the position of the variator lens 4 is detected based on the variator lens position detection data S3 outputted from the analog-to-digital conversion circuit 32.

As a result, the memory circuit 34 is accessed, and the track is detected based on the position detection results of the master lens 8 and the variator lens 4.

Further, based on the detection result, the tracking data is subjected to interpolation calculation processing, and based on the detection result, the master lens 8 is moved in accordance with the movement position of the variator lens 4, and the back focus is corrected so as not to change.

At this time, if the value of the variator lens position detection data S3 does not change despite moving the variator lens 4, the value of the subsequent variator lens position detection data S3 is referred to and the value of the variator lens position detection data S3 is By correcting the value of , and correcting the position of the master lens 4 based on the correction result, the subject can be smoothly enlarged or reduced.

According to the above configuration, by generating the remaining tracking data from five types of tracking data using an interpolation calculation method and correcting the position of the master lens 8,
An inner focus zoom mechanism can be configured with a simple configuration.

Furthermore, at this time, if the value of the variator lens position detection data S3 does not change even though the zoom operator 36B is turned on, the detected variator lens position detection data S3 does not change.
By correcting the value of the lens position detection data S3 and correcting the position of the master lens 8, the subject can be smoothly enlarged or reduced accordingly.

(G2) Other Embodiments Although the above-mentioned embodiments have described the case where the front lens, the variator lens, and the master lens constitute an inner focus zoom lens, the present invention is not limited to this. It can also be widely applied to the case where an inner focus zoom lens is configured by adding a lens.

In this case, as shown in FIG. 6, it is possible to reduce the movement distance of the master lens in response to a change in the position of the variator lens.

Further, in the above-described embodiments, a case has been described in which the present invention is applied to a camera-integrated video tape recorder, but the present invention is not limited to this, but can be widely applied to imaging devices such as television cameras and electronic still cameras. I can do it.

Effects of the Invention As described above, according to the present invention, the position of the master lens can be corrected with a simple configuration by correcting the position of the master lens from tracking data using an interpolation method. You can get the equipment.

Furthermore, at this time, if the value of the variator lens position detection data does not change even though the variator lens has moved, the position of the master lens is corrected by correcting the value of the detected variator lens position detection data. Accordingly, it is possible to obtain an inner focus imaging device that can smoothly enlarge or reduce a subject with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a camera-integrated video tape recorder according to an embodiment of the present invention, FIG. 2 is a characteristic curve diagram for explaining its operation, FIG. 3 is a flowchart for explaining its operation, and FIG. The figure is a characteristic curve diagram showing the movement of the master lens relative to the variator lens, FIG. 5 is a signal waveform diagram for explaining its operation, FIG. 6 is a characteristic curve diagram showing another embodiment, and FIGS. The figure is a route map showing a conventional zoom lens. 1.10.22...Zoom lens, 2...
...Front lens, 4...Variator lens, 8...Master lens, 26.28...
...Drive motor, 3゜...Control circuit, 32...
...Analog-digital conversion circuit, 34. Old...Memory circuit.

Claims (2)

[Claims] (1) In an imaging device that images a desired subject using an inner focus zoom lens that corrects the position of the master lens according to the position of the variator lens, a variator lens moving means that moves the variator lens; variator lens position detection means for detecting the position of the lens and outputting variator lens position detection data; master lens position detection means for detecting the position of the master lens and outputting master lens position detection data; and a subject at a predetermined distance. tracking data storage means for storing tracking data representing the positional relationship between the variator lens and the master lens; and interpolation calculation of the tracking data based on the variator lens position detection data and the master lens position detection data. an imaging apparatus, comprising: a control means for generating correction data based on the correction data, and moving the master lens based on the correction data. (2) In an imaging device that images a desired subject using an inner focus zoom lens that corrects the position of the master lens according to the position of the variator lens, a variator lens moving means that moves the variator lens; variator lens position detection means for detecting the position of the lens and outputting variator lens position detection data; master lens position detection means for detecting the position of the master lens and outputting master lens position detection data; and a subject at a predetermined distance. tracking data storage means for storing tracking data representing the positional relationship between the variator lens and the master lens; and interpolation calculation of the tracking data based on the variator lens position detection data and the master lens position detection data. control means for generating correction data based on the correction data and moving the master lens based on the correction data; When the detection data does not change, the moving direction of the variator lens is detected, and based on the detection result, the value of the variator lens position detection data is corrected to generate the correction data. Imaging device.