JP4856807B2 - Imaging apparatus, imaging system, and imaging method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
It is suitable for use with an electronic imaging apparatus having a means for adjusting the optical mounting state.
[0002]
[Prior art]
FIG. 9 shows a typical configuration diagram of the prior art, and an outline of the operation will be described. Focal length adjustment optical system L1 for adjusting the imaging angle of view, correction optical system L2 according to the movement of the focal length adjustment optical system L1, shift optical system L3 for camera shake correction, aperture mechanism Iris for adjusting the amount of incident light, focus A subject image is formed on the image sensor 1 by the image pickup optical system 8 including the focus position adjustment optical system L4 for adjustment. The formed image is photoelectrically converted by the image pickup device 1 and processed into a color video signal by the video camera signal processing means 3. The processed video signal is output and luminance information is mainly supplied to the exposure control (AE) means 4 and the focus adjustment (AF) means 2 to generate respective control signals.
[0003]
The exposure control unit 4 controls the accumulation time (shutter speed) and the iris mechanism Iris for each screen of the image sensor 1. The focus adjusting unit 2 controls the focus position adjusting optical system L4. The camera shake state is detected by the shake detecting means 7 such as an acceleration sensor, and the shift optical system L3 is driven by the shift optical system driving means (AS / IS) 6 to reduce the shake.
[0004]
When an operation instruction signal for adjusting the imaging angle of view is input to the angle of view adjustment (Zoom) means 5 as required by the user, an electronic cam curve is read from a memory (not shown), and the focal length adjustment optical system L1 Control is performed while the correction optical system L2 is interlocked.
[0005]
As described above, an extremely multi-functional and high-performance imaging system can be realized in a small size. For example, Japanese Patent Laid-Open No. 3-159377 discloses contents relating to an electric tilt control mechanism and multipoint AF evaluation.
[0006]
[Problems to be solved by the invention]
However, in the imaging system of the prior art, since the downsizing of the imaging device is rapidly progressing, extremely high accuracy has been required for mounting the imaging device. As shown in FIG. 10, the angle θ formed by the optical axis of the imaging optical system 8 and the imaging element 1 may be tilted from the vertical due to the manufacturing accuracy of parts, the mounting error in the manufacturing process, and the like. It was difficult to fit inside.
[0007]
The present invention has been made to solve such a problem, and an object of the present invention is to suppress deterioration in image quality due to the tilt of an image sensor in an image capturing apparatus having an angle of view adjusting means.
[0008]
[Means for Solving the Problems]
The image pickup apparatus of the present invention can be mounted with a lens apparatus having an image pickup optical system having an angle of view adjusting means and a first storage means for storing information related to the relative position of the image pickup optical system with respect to a reference value, An image pickup apparatus having photoelectric conversion means for photoelectrically converting an image formed by the image pickup optical system , wherein the first storage means stores information relating to a relative position of the photoelectric conversion means with respect to a reference value; and using the read information from the second storage means, transmitting and adjusting means of the relative position be adjusted according to the relative position in the angle of view of the imaging optical system, an instruction to change the angle to the lens device And receiving information related to the relative position of the imaging optical system with respect to the reference value corresponding to the angle of view to be changed, stored in the first storage means, and the imaging light with respect to the received reference value The inclination of the photoelectric conversion means based on the information on the relative position of the system and the information on the relative position of the photoelectric conversion means with respect to the reference value corresponding to the angle of view to be changed stored in the second storage means Control means for controlling the relative position adjusting means to adjust the relative position .
[0013]
The imaging system of the present invention, a lens replacement comprising a camera unit having a lens unit having an imaging optical system having a field angle adjusting means, the photoelectric conversion means to photoelectrically convert an image formed by the imaging optical system A first control unit that controls the lens unit, a second control unit that controls the camera unit, and the imaging optical system corresponding to a plurality of angles of view of the imaging optical system. A storage unit for storing information on a relative position between a system and the photoelectric conversion unit, and a relative unit that adjusts the relative position according to an angle of view of the imaging optical system, using the information read from the storage unit. Position adjusting means, and the storage means stores first storage means for storing information on the relative position of the imaging optical system with respect to a reference value, and information on the relative position of the photoelectric conversion means with respect to a reference value. Is composed of a second storage means for憶, the lens portion comprises said first storage means, viewing including the camera unit and the second storage means, said first control means, the second When an instruction to change the angle of view is received by the control means, information relating to the relative position of the imaging optical system with respect to the reference value corresponding to the angle of view to be changed is stored in the first storage means. The second control means stores information related to the relative position of the imaging optical system with respect to the reference value received from the first control means, and is stored in the second storage means. And controlling the relative position adjustment means to adjust the inclination of the photoelectric conversion means based on information on the relative position of the photoelectric conversion means with respect to the reference value corresponding to the angle of view to be changed. Toss .
[0016]
The imaging method of the present invention can be equipped with a lens device having an imaging optical system having an angle of view adjusting means and a first storage means for storing information relating to a relative position of the imaging optical system with respect to a reference value , An imaging method in an imaging apparatus having photoelectric conversion means for photoelectrically converting an image formed by the imaging optical system, the first step of detecting an angle of view of the imaging optical system, and an instruction to change the angle of view A second step of acquiring information relating to the relative position of the imaging optical system with respect to the reference value corresponding to the angle of view to be changed, and information relating to the relative position of the imaging optical system with respect to the acquired reference value; a third controlled to adjust the inclination of said photoelectric conversion means on the basis of the information about the relative positions of the photoelectric conversion means with respect to the reference value corresponding to the angle to said change And having a step.
[0019]
[Action]
According to the present invention, the angle θ formed by the optical axis of the imaging optical system and the imaging element is actively controlled by the relative position variable means. Therefore, the angle θ can be suppressed as small as possible. Particularly, by controlling the angle θ based on the angle of view of the imaging optical system, a good image can be obtained even when the angle θ varies according to the change in the angle of view. Obtainable.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Several embodiments of the present invention will be described below with reference to the drawings.
[0021]
(First embodiment)
First, the first embodiment will be described. FIG. 1 is a schematic diagram showing a basic concept of angle adjustment. As shown in FIG. 1, the angle adjustment needs to be performed in two vertical (Y-axis) (X-axis) and two horizontal axes with respect to the imaging screen. In the following description, components having the same functions as the components described in FIG. 9 are denoted by the same reference numerals as those in FIG.
[0022]
In FIG. 4, a circular area including an effective image formed by the imaging optical system 8 is within the effective image circle of FIG. 1, and the largest rectangular imaging area inscribed in the circle is area A, and 2 Area B is a safe area free from vignetting in consideration of the shaft adjustment work.
[0023]
In this embodiment, an effective imaging area in which each θ (θx, θy) formed by the optical axis of the imaging optical system 8 and the imaging device 1 described in FIG. 10 is adjusted with respect to each of the X axis and the Y axis. An imaging signal is formed and output as area B.
[0024]
A method of measuring an error from the reference value will be described with reference to FIG. When the imaging optical system 8 having the above-described configuration is a measurement target, a measurement test chart having frequency components of the X axis and the Y axis is used as a reference imaging in which the imaging optical system 8 is installed at the reference mounting position. An image is formed on the element 40, and this information is photoelectrically converted and output. The photoelectric conversion signal is converted into a color (or monochrome) video signal by the well-known video camera signal processing means 3 and supplied to the evaluation means 41 to evaluate the relative position between the optical system and the reference image sensor 40. As the imaging optical system 8, zoom lenses, particularly zoom lenses with a high zoom ratio, are becoming mainstream, and changes in zoom position or focal length and FNo. Changes greatly, and the depth of focus changes greatly. In addition, the number of zoom lenses with high sensitivity increases, and the tilt direction and angle of the ideal image plane may vary greatly due to manufacturing errors.
[0025]
Therefore, it is necessary to correct the fluctuation of the tilt angle of the image plane according to the zoom position of the imaging optical system 8 as needed. The zoom position of the imaging optical system 8 is tilted with respect to the X and Y axes at a plurality of points from the wide-angle end to the telephoto end, and the tilt angle with the highest frequency component is detected, and this angle (from the reference value) The error memory 42 provided in the imaging optical system unit 50 has a table for each zoom (view angle) position, and stores each parameter value.
[0026]
This memory is composed of a nonvolatile memory such as an EEPROM, for example, and is configured to be read from a system microcomputer on the camera side having the combined image sensor 40 when the image pickup system is assembled by combining the image pickup optical system 8 and the image pickup element 1. ing.
[0027]
Similarly, it is possible to measure the error of the mounting position of the reference image pickup device 40 based on the image pickup optical system 8 serving as a reference, and it is possible to provide storage means for storing error information of the image pickup device 40. In the interchangeable lens system, it is possible to construct an effective system by separately providing this storage means for each interchangeable lens.
[0028]
In order to further improve the accuracy, it is necessary to correct fluctuations in the tilt angle of the image sensor 40 due to temperature changes in the apparatus. Therefore, in order to store error values corresponding to a plurality of temperatures, a table is provided for each temperature. Each parameter value can be stored. For example, 5 to 6 measurement temperatures are stored in increments of 20 ° C., centering on 20 ° C. at normal temperature. For example, the measurement temperature is set to -20 ° C, 0 ° C, 20 ° C, 40 ° C, 60 ° C.
[0029]
FIG. 3 shows the concept of adjustment by two axes of XY. Mountain climbing control using a so-called TV signal is performed for the X axis and the Y axis to optimize the entire screen. For example, the Y-axis is fixed to an arbitrary value, and hill-climbing control is first performed so that the high-frequency component in the X-axis direction becomes the maximum value. Next, hill-climbing control of the Y-axis component is executed with the X-axis value fixed to the X-axis vertex, and the vertex value on the X-axis at this time and the inclination angle θx corresponding to the vertex value on the Y-axis Each θy is stored.
[0030]
Hereinafter, a configuration example of the imaging apparatus according to the first embodiment will be described with reference to FIG. In the first embodiment, the imaging optical system 8 and its various parameters are controlled using each control data by each processing means (AF, AE, AS / IS, Zoom, Iris).
[0031]
In the present embodiment, the adjustment based on the zoom (view angle) information is positively performed especially in the steady control. The system control means 9 first measures the temperature in the apparatus with the temperature sensor 61, and has a value closest to the measured temperature among the various parameter values for each temperature stored in advance in the error memory 42. Error information is read from the table, and simultaneously or thereafter, the zoom (view angle) position of the imaging optical system 8 is detected, and error information from the table closest to the zoom (view angle) position is read, and each value Relative position correction according to the value obtained by calculating is performed as needed according to the change in the zoom (view angle) position.
[0032]
As a correction method, the attachment inclination angles in the X direction and the Y direction of the image sensor 1 are adjusted by the drive units 11 and 12 shown in FIG. Thereby, the relative position of the imaging optical system 8 and the imaging device 1 can be adjusted.
[0033]
As the driving means 11 and 12, for example, an actuator such as a stepping motor, a voice coil motor, or a piezoelectric element can be used.
[0034]
The above adjustment procedure is shown as a flowchart for adjustment in FIG. Hereinafter, each step (S1-S8) of the flowchart of FIG. 5 will be described.
[0035]
First, in step S1, power-on is detected. When power-on is detected, the zoom position of the image pickup optical system is detected in step S2, and the adjustment of the tilt angle of the image pickup device 1 is started in step S3. In the next step S4, data is read from the error memory, and in step S5, X-axis adjustment is executed based on the read data. In the next step S6, Y-axis adjustment is executed based on the similarly read data.
[0036]
In the next step S7, it is detected whether or not the adjustment of both axes has been completed. When the adjustment is finished, the adjustment is finished in the next step S8. However, after that, the zoom position of the imaging optical system 8 is always monitored, and when the zoom position is changed, the process returns to step S2. Shooting is performed while performing the above operations.
[0037]
As described above, according to the first embodiment of the present invention, an error from the reference value of the optical system is stored in advance according to factors such as assembly accuracy, zoom position, temperature, and the like. In various combinations of the system 8 and the image pickup device 1, good characteristics can be realized even when the image pickup optical system 8 is inclined with respect to the image pickup device 1.
[0038]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the present invention is applied to an imaging system including an interchangeable lens video camera. The video camera according to the present embodiment is roughly divided into a lens part and a camera part, each having a microcomputer as system control means 16 and 18, and executing data communication between the microcomputers. Also in the second embodiment, components having the same functions as the components described in FIG. 9 and the respective drawings of the first embodiment are denoted by the same reference numerals, and a part of the description is omitted. .
[0039]
In the second embodiment, error memories 17 and 19 for detecting an error from the reference by the reference image pickup device 40 and the like and storing the error are provided in both the lens unit and the camera unit. Here, the data stored in the error memory 17 of the lens unit is data detected using the reference imaging device 40 as in the first embodiment, and the data stored in the error memory 19 of the camera unit is This is data detected by attaching the reference optical system to the camera unit by the same method.
[0040]
Prior to the steady operation, the system control means 16 of the lens unit first measures the temperature in the lens with the temperature sensor 81, and simultaneously detects the zoom (field angle) position of the imaging optical system 8 and stores it in the error memory 17. Read the error information based on the zoom (view angle) position using a table of values closest to the measured temperature from various parameter values stored in advance for each temperature. The information is transmitted from the means 16 to the system control means 18 of the camera unit.
[0041]
Almost simultaneously with this operation, the system control means 18 of the camera unit measures the temperature in the camera body with the temperature sensor 82, and various parameters for each of a plurality of temperatures stored in advance in the error memory 19 of the camera unit. Among the values, error information is read out using a table of values closest to the measured temperature, and is used together with the error information value transmitted from the lens unit to control the position of the image sensor 1 by a correction method described later. .
[0042]
By storing temperature sensors and error memory tables in both the camera unit and lens unit so that they can handle multiple temperatures, even when the temperature of the camera unit differs from the temperature of the lens unit, more appropriate correction is possible. Can be executed.
[0043]
Focal length adjustment optical system L1 for adjusting the imaging angle of view, correction optical system L2 according to the movement of the focal length adjustment optical system L1, shift optical system L3 for camera shake correction, aperture mechanism Iris for adjusting the amount of incident light, focus A subject image is formed on the image sensor 1 by the image pickup optical system 8 including the focus position adjustment optical system L4 for adjustment. The formed image is photoelectrically converted by the image sensor 1 and processed into a color video signal by the video camera signal processing means 3. The processed video signal is output, and luminance information is mainly supplied to the exposure control unit 4 and the focus adjustment unit 2 to generate respective control signals and input to the system control unit 18. Control data from the exposure control unit 4 and the focal length adjustment unit 2 is transmitted from the system control unit 18 of the camera unit to the system control unit 16 of the lens unit, and controls the iris mechanism Iris and the focal position adjustment optical system L4. The exposure control means 4 also controls the accumulation time for each screen of the image sensor 1 as necessary.
[0044]
The camera shake state is detected by the blur detection means 7 such as an acceleration sensor on the lens side, and the shift optical system L3 is driven by the shift optical system drive means (AS / IS) 6 to reduce the blur.
[0045]
Further, when an operation instruction signal for adjusting the imaging angle of view is input to the system control microcomputer 18 as required by the user, it is transmitted to the lens side microcomputer, and an electronic cam curve is read from a memory (not shown) provided on the lens side. Control is performed while the focal length adjusting optical system L1 and the correction optical system L2 are interlocked.
[0046]
The temperature information and the zoom position are always monitored. When an instruction to change the zoom position is received from the system control means 16 of the lens unit, the error information stored in the error memory 17 corresponding to the zoom position is read and the value is read. Is transferred to the system control means 18 of the camera unit, and the tilt position control of the image sensor 1 is performed at any time.
[0047]
Next, the correction method will be described in detail with reference to the error correction table of FIG. In FIG. 7, the X axis error is the error angle and shift amount from the reference position in the X axis direction, the Y axis error is the error angle and shift amount from the reference position in the YX axis direction, and the Z axis error is in the ZX axis direction. The error angle from the reference position and the shift amount are shown.
[0048]
First, (L1-C1), (L3-C3), and (L5-C5) are calculated. For the calculation results of {1-COS (L1-C1)}, {1-COS (L3-C3)}, {1-COS (L5-C5)}, (L2-C2), (L4- The correction data is calculated in consideration of C4) and (L6-C6).
[0049]
FIG. 8 is a flowchart showing an operation procedure of the system control unit 16 of the lens unit and the system control unit 18 of the camera unit. With reference to FIG. 8, the operation procedure of the system control unit 16 of the lens unit and the system control unit 18 of the camera unit will be described.
[0050]
First, lens loading is detected in step S11. If a lens is mounted, the zoom (view angle) position of the lens is detected in step S12, and error data stored in the error memory 17 on the lens side is transmitted to the camera side in step S13.
[0051]
On the camera side, the error data transmitted in step S21 is received. Then, in step S22, error data is read from the error memory 19 of the camera unit and integrated with the lens error data received in step S23 to generate each correction data as described above.
[0052]
Next, in step S24, X-axis adjustment is executed based on the generated correction data, and in step S25, Y-axis adjustment is executed based on the generated correction data. In step S26, if the adjustment is completed, the process ends. However, after that, the zoom position is always monitored, and when a change occurs, the process returns to step S12 to restart the process.
[0053]
As described above, according to the second embodiment of the present invention, in the interchangeable lens imaging system, the error memories 17 and 19 are provided in the lens unit and the camera unit, respectively, so that the lens is replaced. Even if it exists, it becomes possible to correct | amend deterioration of the image quality by the inclination of the image pick-up element 1, and a highly compatible system can be constructed | assembled. Furthermore, since the temperature sensors 81 and 82 and the error memories 17 and 19 are stored in both the camera and the lens in correspondence with a plurality of temperatures, even when the temperature of the camera unit and the temperature of the lens unit are different, more appropriate. Correction can be performed. Furthermore, in the zoom optical system, the tilt of the image sensor 1 can be optimally corrected as needed according to the zoom (view angle) position.
[0054]
【Effect of the invention】
According to the present invention, it is possible to correct image quality deterioration caused by the tilt of the image sensor. Therefore, it is possible to provide an imaging apparatus, an imaging method, and an imaging system that can obtain a high-quality image.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a basic concept of adjustment according to each embodiment of the present invention.
FIG. 2 is a schematic diagram showing a basic concept of measurement according to each embodiment of the present invention.
FIG. 3 is a schematic diagram showing a concept of adjustment according to each embodiment of the present invention.
FIG. 4 is a schematic diagram illustrating a configuration of an imaging apparatus according to the first embodiment of the present invention.
FIG. 5 is a flowchart showing a processing procedure according to the first embodiment of the present invention.
FIG. 6 is a schematic diagram illustrating a configuration of an imaging system according to a second embodiment of the present invention.
FIG. 7 is a schematic diagram showing an error table of the imaging system according to the second embodiment of the present invention.
FIG. 8 is a flowchart showing a processing procedure according to the second embodiment of the present invention.
FIG. 9 is a schematic diagram illustrating a configuration of a conventional imaging device.
FIG. 10 is a schematic diagram showing a basic concept of adjustment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image pick-up element 2 Focus adjustment means 3 Video camera signal processing means 4 Exposure control means 5 View angle adjustment means 6 Shift optical system drive means (AS / IS)
7 Shake detection means 8 Imaging optical system 9, 16, 18 System control means 11, 12 Driving means 17, 19, 42 Error memory 40 Reference imaging device 41 Evaluation means 50 Imaging optical system units 61, 81, 82 Temperature sensor L1 Focal length Adjustment optical system L2 Correction optical system L3 Shift optical system L4 Focus position adjustment optical system
Iris iris mechanism

Claims (9)

A lens apparatus having an imaging optical system having an angle-of-view adjusting unit and a first storage unit that stores information on a relative position of the imaging optical system with respect to a reference value can be mounted, and imaging is performed by the imaging optical system. An image pickup apparatus having a photoelectric conversion means for photoelectrically converting a captured image,
Second storage means for storing information relating to the relative position of the photoelectric conversion means with respect to a reference value;
Using the information read from the first and second storage means, and adjusting means of the relative position be adjusted according to the relative position in the angle of view of the imaging optical system,
An instruction to change the angle of view is transmitted to the lens apparatus, and information related to the relative position of the imaging optical system with respect to the reference value corresponding to the angle of view to be stored, which is stored in the first storage unit, is received. Information on the relative position of the imaging optical system with respect to the received reference value, and information on the relative position of the photoelectric conversion means with respect to the reference value corresponding to the angle of view to be changed stored in the second storage means And a control means for controlling the relative position adjusting means so as to adjust the inclination of the photoelectric conversion means based on the above . The imaging apparatus according to claim 1 , wherein the adjustment by the relative position adjustment unit is performed using information stored in the first and second storage units. The storage means stores information on relative positions of the imaging optical system and the photoelectric conversion means corresponding to a plurality of angles of view of the imaging optical system for each of a plurality of temperatures. Item 3. The imaging device according to Item 1 or 2 . A lens unit having an imaging optical system having a field angle adjusting means, a lens interchangeable imaging system consisting of a camera unit having a photoelectric conversion means to photoelectrically convert an image formed by the imaging optical system ,
First control means for controlling the lens unit;
Second control means for controlling the camera unit;
Storage means for storing information on relative positions of the imaging optical system and the photoelectric conversion means corresponding to a plurality of angles of view of the imaging optical system;
Using the information read from the storage means, the relative position adjustment means for adjusting the relative position according to the angle of view of the imaging optical system,
The storage unit includes a first storage unit that stores information on a relative position of the imaging optical system with respect to a reference value, and a second storage unit that stores information on the relative position of the photoelectric conversion unit with respect to a reference value. And
Wherein the lens unit includes a first storage unit, the camera unit is viewed contains the second storage means,
When the first control means receives an instruction to change the angle of view by the second control means, the first control means stores the reference value corresponding to the angle of view to be changed, which is stored in the first storage means. Sending information about the relative position of the imaging optical system to the second control means;
The second control unit is configured to change the angle of view stored in the second storage unit and information regarding the relative position of the imaging optical system with respect to the reference value received from the first control unit. The relative position adjusting means is controlled to adjust the inclination of the photoelectric converting means on the basis of the information on the relative position of the photoelectric converting means with respect to the corresponding reference value . The imaging system according to claim 4 , wherein the adjustment by the relative position adjusting unit is performed using information stored in the first and second storage units. The storage means stores information on relative positions of the imaging optical system and the photoelectric conversion means corresponding to a plurality of angles of view of the imaging optical system for each of a plurality of temperatures. Item 6. The imaging system according to Item 4 or 5 . A lens apparatus having an imaging optical system having an angle-of-view adjusting unit and a first storage unit that stores information on a relative position of the imaging optical system with respect to a reference value can be mounted , and image formation is performed by the imaging optical system. An imaging method in an imaging apparatus having a photoelectric conversion means for photoelectrically converting a captured image ,
A first step of detecting an angle of view of the imaging optical system;
A second step of receiving information on a relative position of the imaging optical system with respect to the reference value in response to an instruction to change the angle of view ;
The inclination of the photoelectric conversion means is determined based on information on the relative position of the imaging optical system with respect to the acquired reference value and information on the relative position of the photoelectric conversion means with respect to the reference value corresponding to the angle of view to be changed. And a third step of controlling to adjust . 8. The imaging method according to claim 7 , wherein, in the third step, adjustment of a relative position with respect to the imaging optical system is performed in each of the X-axis and Y-axis directions of the photoelectric conversion means. Wherein when the angle of view of the imaging optical system after the third step is changed, according to claim 7 or 8 returns to the first step, and carrying out the first to third step The imaging method described in 1.

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