JP3704453B2 - Image lens displacement detection method and system, and displacement correction method and system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a focus correction system for adjusting the focus of an optical sensor mounted on an artificial satellite and observing the ground with high accuracy.
[0002]
[Prior art]
In an artificial earth observation system, in order to obtain high resolution characteristics, it is necessary to increase the resolution and brightness by increasing the size of the lens and to adjust the focal position of the large lens with high accuracy. This earth observation system is required to have extremely low thermal strain characteristics with respect to the environmental conditions of the orbit of the satellite.
Conventionally, when adjusting the focus on the trajectory, a method of moving the adjustment mechanism to find the best image position has been adopted. This method of detecting the focal position of the lens and always closing and controlling the automatic control loop so that the imaging sensor is always at the best image position has a complicated optical system and control system in the conventional configuration, and the size of the apparatus is large. In order to be accommodated in a satellite that is large and has a limited volume, it was necessary to sacrifice the mounting of other observation substrates.
There is also a method of fixing the focal point before launching the satellite, but this method prevents the focal point from changing due to disturbance such as thermal distortion caused by the bias of sunlight radiation in orbit. It is necessary to devise the structure, and for this reason, it is costly to select a special material with little thermal deformation and to design and manufacture a combination of materials with different temperature characteristics and a combination of structures, resulting in a very expensive system. It was.
[0003]
The so-called autofocus method, which is an automatic focus detection method and a focus correction method, is equipped with a light source that irradiates the subject with light, measures the amount of defocus and the distance to the subject from the reflected light from the subject, and forms an image. There are an active system that controls the position of the lens and a passive system that does not include a light source and detects a defocus from light from an object. In the case of satellites, the passive method must be adopted.
Typical error detection methods in autofocus are a contrast method and a phase difference detection method. In the contrast method, while moving either the object or the imaging lens in the optical axis direction, a contrast signal is acquired from the focus sensor, and the object or lens is always in the in-focus position where the contrast signal is maximized. Is often used in an optical apparatus such as a microscope or an exposure apparatus that can place an object on a stage or the like that can move in the optical axis direction. Since this method does not know whether the position of the object or the imaging lens is in front of or behind the focal point, it is necessary to move the lens and stage back and forth, and it takes time until the control system converges. There is a difficulty.
On the other hand, in the phase difference detection method, image light diverged again from the focal position of the imaging lens is re-imaged on two line sensors at different positions by the separate lens, and on the two line sensors before and after the focal position. Since the position (phase) of the maximum contrast of the image connected to is changed, the position of the imaging lens is controlled so as to have a predetermined phase relationship, and is generally used in cameras and the like. The line sensor is required and the system becomes complicated.
The focus correction system mounted on the earth observation system of an artificial satellite is desired to have a stable and highly reliable configuration with a small number of parts because the environmental conditions change greatly.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and an object thereof is to provide a stable and highly reliable focus correction system that solves the above-described problems by detecting and correcting defocus on the trajectory.
[0005]
[Means for Solving the Problems]
According to the imaging lens position shift detection method of the present invention, an image formed by the imaging lens is photoelectrically converted by an imaging linear sensor, and the imaging lens and the imaging linear sensor are mounted and orthogonal to the pixel arrangement direction of the linear sensor. In an imaging system that acquires a two-dimensional image to be imaged by moving in the direction of the image, a positional deviation different from the imaging linear sensor arranged so that the imaging plane of the imaging lens and the pixel array direction intersect In the detection linear sensor, the light receiving position coordinate at which the contrast of the image formed by the imaging lens is maximized within the light receiving surface, the light receiving position coordinate at which the contrast of the image formed by the imaging lens within the light receiving surface is maximized, and the above The light receiving position coordinate at which the contrast is maximized is detected from the difference between the pixel position coordinate of the point of intersection with the imaging surface of the imaging lens of the position detection linear sensor. If not, the light receiving position coordinate where the contrast between the scan lines that are acquired back in time with respect to the moved image in the direction orthogonal is maximum and the pixel arrangement direction, the linear sensor the positional deviation detection The amount of deviation from the optimal position on the optical axis for optimal imaging of the imaging lens on the imaging linear sensor is calculated from the difference between the coordinates of the pixel position of the point intersecting the imaging surface of the imaging lens. It is characterized by that.
In addition, the imaging lens positional deviation correction method of the present invention photoelectrically converts an image formed by the imaging lens by the imaging linear sensor, and mounts the imaging lens and the imaging linear sensor to change the pixel arrangement direction of the linear sensor. In an imaging system that moves in an orthogonal direction to acquire a two-dimensional image, positional deviation detection is separate from the imaging linear sensor arranged so that the imaging plane of the imaging lens and the pixel array direction intersect the use linear sensor, the light receiving position coordinates contrast of an image formed by the imaging lens in the light receiving plane is maximized, the position and light receiving position coordinates contrast is maximum of the image formed by the imaging lens in the light-receiving surface The light receiving position coordinate at which the contrast is maximized can be detected from the difference from the coordinate of the pixel position of the point intersecting the imaging surface of the imaging lens of the linear sensor for deviation detection. If no, the light receiving position coordinate where the contrast between the scan lines that are acquired back in time with respect to the moved image in the direction orthogonal is maximum and the pixel arrangement direction, the linear sensor the positional deviation detection The amount of deviation from the optimal position on the optical axis for optimal imaging of the imaging lens on the imaging linear sensor is calculated from the difference between the pixel position coordinates of the point intersecting the imaging surface of the imaging lens. The imaging lens is moved to an optimum position based on the calculated result.
In addition, the imaging lens misregistration detection system of the present invention photoelectrically converts an image formed by the imaging lens by the imaging linear sensor, and includes the imaging lens and the imaging linear sensor, and the pixel array direction of the linear sensor is In an imaging system that acquires a two-dimensional image by moving in an orthogonal direction, a position shift detection that is different from the imaging linear sensor arranged so that the imaging plane of the imaging lens and the pixel arrangement direction intersect each other With respect to the image of the linear sensor that moves in a direction perpendicular to the pixel array direction and deviates from the pixel array, where the contrast of the image formed by the imaging lens within the light receiving surface is maximum, or out of the pixel array Means for detecting one or both of the light receiving position coordinates at which the contrast between the scanning lines acquired at a maximum time is maximized, and the light receiving position at which the contrast is maximized The optimal position on the optical axis for the imaging lens to optimally form an image on the imaging linear sensor based on the difference between the mark and the coordinates of the pixel position at the point where it intersects the imaging surface of the imaging lens of the linear sensor for detecting displacement A means for calculating a deviation amount from the distance is provided.
In addition, the imaging lens positional deviation correction system according to the present invention photoelectrically converts an image formed by the imaging lens by the imaging linear sensor, and includes the imaging lens and the imaging linear sensor to change the pixel array direction of the linear sensor. Is different from an imaging linear sensor arranged so that the imaging plane of the imaging lens and the pixel arrangement direction intersect in an imaging system that acquires a two-dimensional image of the earth surface by moving in an orthogonal direction The first light receiving position coordinate at which the contrast of the image formed by the imaging lens within the light receiving surface of the linear sensor for position shift detection and the linear sensor for position shift detection is maximized, and the pixel arrangement direction are orthogonal to each other. means for detecting a second light receiving position coordinates contrast between scan lines are acquired back in time with respect to an image that has moved in the direction is maximum, the first or second The difference from the linear sensor imaging lens imaging the light receiving position coordinates select, selected receiving position coordinates and the coordinates of the pixel position of a point intersecting with the imaging plane of the imaging lens of the positional shift detection linear sensor And a means for calculating a deviation amount from the optimal position on the optical axis for optimal image formation, and a means for moving the imaging lens to the optimal position based on the calculated result.
In addition, a means for detecting the light receiving position coordinate at which the contrast is maximum is provided for each pixel between the photoelectrically converted image output signal of the positional deviation detection linear sensor and the image signal obtained by delaying the image output signal by a predetermined time. Means for obtaining a difference in signal amplitude and means for detecting a pixel arrangement position on the light receiving surface of the linear sensor of a pixel that gives the maximum difference value of the differenced signal may be provided.
In addition, the means for detecting the coordinates of the light receiving position where the contrast is maximum further detects a step having a gradation higher than a predetermined height in the image signal output by photoelectric conversion of the positional deviation detection linear sensor. And a means for connecting the output image signal of the linear sensor for detecting displacement to a means for obtaining a difference in signal amplitude for each pixel between the image signal and the image signal obtained by delaying the image output signal by a predetermined time. May be.
An image obtained by delaying the image signal and the image output signal by a predetermined time when a step having a gradation higher than a predetermined height is detected in the image signal output by photoelectric conversion of the position shift detection linear sensor. The means for connecting the output image signal of the positional deviation detection linear sensor to the means for taking the signal amplitude difference for each pixel from the signal is further converted into the image signal when there is an instruction input from the outside of the means. There may be provided means for starting detection of a step having a gradation higher than a predetermined height.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a defocus detection system in a focus correction system of the present invention incorporated in an imaging optical system of an earth observation system mounted on an artificial satellite. The imaging optical system of the satellite earth observation system is provided with a plurality of solid-state imaging sensors in order to perform high-resolution imaging. In FIG. 1, image information captured by the imaging lens 1 is converted into electrical signals by a plurality of one-dimensional licensors CCD2-4. The CCD 2 and the CCD 3 are line sensors for acquiring an image of an object on the ground, and these light receiving surfaces are arranged to face the lens 1 at right angles to the optical axis of the lens. On the other hand, the CCD 4 is a correction CCD for detecting a defocus, and its imaging surface is within the plane formed by the pixel array axis and the optical axis of the lens 1, and the pixel array axis and the lens optical axis. Are arranged at an angle from a right angle. For example, it is assumed that the central portion of the pixel array of the line sensor CCD 4 is installed on the focal plane of the lens 1. At this time, since the light receiving surfaces of the right and left pixels far from the vicinity of the center of the pixel array are shifted back and forth from the focal position, the sharpness of the acquired image of the CCD 4 is high in the center of the pixel array in the pixel line. It will have a unimodal distribution that decreases with increasing distance.
Adjustment of the imaging CCDs 2 and 3 to the focal position of the lens 1 is performed on the ground. At the same time, the focal position of the lens 1 on the pixel array of the CCD 4 disposed obliquely with respect to the focal plane is also measured in advance and stored. Further, the positional relationship between the CCDs is mechanically ensured so as not to fluctuate with respect to environmental changes on the orbit.
By adopting the configuration and arrangement as described above, even when the positions on the optical axis of the CCD 2 and the CCD 3 on the orbit are shifted from the focal position of the lens 1 that was initially adjusted by the movement of the lens 1, this is possible. The shift can be detected from the image of the CCD 4 and the defocus can be automatically detected.
[0007]
Next, the operation of the focus correction system that detects the focus position shift by the CCD 4 and corrects the lens position will be described.
FIG. 2 is a block diagram showing the configuration of an embodiment of the focus correction system of the present invention. In the focus correction system of the present invention, image information from a subject is converted into an electrical signal by the measurement CCD 6 and the correction CCD 7 via the lens unit 5. The output level of the electrical signal is output as the electrical signal level for each pixel in the image processing units 81 and 82. The output of the measurement CCD 6 is transmitted to the ground as an image signal 85.
The image signal obtained by the image processing unit 82 of the correction CCD 7 has a waveform with a peak at the focused position because the CCD 7 is mounted at an angle rather than perpendicular to the optical axis of the lens. . The peak position can be detected by the sharpness detection unit 83, and the current focal position of the lens can be detected. Then, in the focus adjustment circuit 84, the correct focus position information of the lens unit 5 on the pixel array of the CCD 7 stored in advance during the adjustment on the ground and the current focus position detection result output from the sharpness detection unit 83. Thus, it is possible to determine a correction value for returning to the correct focus position and adjust the focus of the lens unit 5 to the optimum value by the lens focus adjustment unit 9.
[0008]
FIG. 3 shows a more detailed configuration of the sharpness detection unit 83 that detects the focal position. The image signal of the correction CCD 7 output from the image processing unit 82 is input to the edge detection unit 86. The edge detection unit operates in two modes. One is a self operation, and the second is a remote operation from the ground. In the self operation, the image signal is automatically connected to the delay circuit 87 and the difference circuit 88 when a step having a gradation higher than a predetermined height in the image signal input by the edge detection unit 86 is detected. The gradation steps described above correspond to edge images with clear outlines, such as coastlines and rivers on the earth's surface. In remote operation from the ground, when it is confirmed that edge images with clear outlines such as coastlines and rivers on the earth surface cross over the correction CCD by monitoring at the satellite ground control station and orbit information of the satellite, After the edge detection unit 86 receives the focus correction instruction signal 92 from the ground, the edge detection unit 86 detects a step having a gradation higher than a predetermined height in the input image signal. Then, the image signal is connected to the delay circuit 87 and the difference circuit 88. The delay circuit 87 delays the image signal by one pixel to several pixels of the CCD 7. The difference circuit 88 calculates the difference between the non-delayed image signal and the delayed image signal. That is, the contrast between adjacent or separated pixels is extracted. The difference signal between the pixels is compared for all the pixels by the difference value comparison unit 89, and the maximum value of the difference is detected by the maximum value detection unit 90. The focal position detection unit 91 detects the position of the pixel of the CCD 7 where the difference is the maximum, that is, the focal position information on the CCD 7 and outputs it to the focal adjustment circuit 9. The focus adjustment circuit 9 compares the focus position information at this time point from the focus position detection unit 91 with the correct focus position information that has been stored in advance and has been adjusted in advance, and corrects it to return to the correct focus position. The value is calculated and output to the lens focus adjustment unit 9. The lens focus adjustment unit 9 controls the movement of the lens unit 5 on the optical axis based on the correction value. Information on the magnitude of defocus detected by the focus adjustment circuit 84 is also communicated to the ground control station.
[0009]
As described above, the focus correction system of the present embodiment has the array sensor disposed obliquely to the lens optical axis on the imaging lens focal plane, and further has a predetermined focal position reference. The positive or negative direction of the deviation can be discriminated, and the focus correction is immediately performed by one correction operation. Therefore, high-speed correction is possible. Further, unlike the phase difference detection type autofocus system of the camera, no special optical component for forming a subject image on each of the two line sensors is required. Therefore, high stability can be obtained against severe environmental fluctuations in outer space due to the low number of parts.
[0010]
In the above description, the edge detection unit 86 constituting the focus correction system has, in the input image signal, a gradation of a predetermined height or higher corresponding to an edge image having a clear contour such as a coastline or river on the earth surface. When the step is detected, the image signal is connected to the delay circuit 87 and the difference circuit 88, and the delay circuit 87 delays the image signal by one pixel or several pixels of the CCD 7. Here, the delay time of the delay circuit of the delay circuit is set to one pixel or several pixels, assuming that the edge image substantially intersects the pixel line of the CCD 7. However, an edge image with a clear outline such as a coastline or river on the surface of the earth may be parallel to the pixel line. In this case, the delay time of the delay circuit 87 is one line scan of the CCD 7. In this case, the difference circuit does not take the difference between the pixels of the CCD 7 but calculates the difference between the scanning lines. Whether the edge image intersects the pixel line or the parallel line segment can be automatically switched by the gradation step determination of the edge detection unit. That is, if a step having a gradation of a predetermined height or more between pixels of the input image signal cannot be detected, the edge detection unit instructs the delay circuit to change the delay time so as to perform a difference between lines. It may be configured.
[0011]
In the above description, a case has been described in which the focus adjustment circuit calculates the focus correction value and moves the lens to the correction position by one edge detection by the edge detection unit, whether the self operation or the remote operation. In other words, the operation of an open control system is described instead of the closed loop automatic control system.
However, for example, while the edge image of a coastline or river on the earth continues in time, it is possible to close the control system loop to make an automatic control loop. While the gradation step having a predetermined height is detected in the input image signal, the image signal is continuously output to the subsequent circuit unit, and the output of the focus adjustment circuit 84 always maintains 0. 3 operation modes may be set.
[0012]
The present invention is not limited to the above-described embodiment. For example, the CCD line sensor of this embodiment may be another one-dimensional sensor such as a CMOS linear array sensor. Further, the present invention can be applied not only to a solid-state imaging device but also to an apparatus using a two-dimensional image sensor including an imaging tube. Furthermore, the present invention can also be applied to an autofocus system of various optical apparatuses that constitute an automatic control system that detects a defocus and feeds back this to automatically correct the focus.
[0013]
【The invention's effect】
As described above, according to the focus correction system having a simple configuration of the present invention, it is possible to automatically adjust even if there is a disturbance such as an environmental condition on the orbit and the focus position is shifted, which is stable and high. It has the feature that it is highly reliable and contributes to the improvement of the operational efficiency of the earth observation system for artificial satellites.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a defocus detection system of a focus correction system of the present invention.
FIG. 2 is a block diagram showing a system configuration example of the focus correction system of the present invention.
FIG. 3 is a diagram showing a more detailed configuration of a sharpness detection unit constituting the focus correction system of the present invention.
[Explanation of symbols]
1 Lens 2 CCD
3 CCD
4 CCD
5 Lens unit 6 CCD for measurement
7 CCD for correction
DESCRIPTION OF SYMBOLS 9 Lens focus adjustment part 81 Image processing part 82 Image processing part 83 Sharpness detection part 84 Focus adjustment circuit 85 Image signal 86 Edge detection part 87 Delay circuit 88 Difference circuit 89 Difference value comparison part 90 Maximum value detection part 91 Focus position detection part 92 Focus correction instruction signal

Claims (10)

An image formed by the imaging lens is photoelectrically converted by an imaging linear sensor, and the imaging lens and the imaging linear sensor are mounted and moved in a direction orthogonal to the pixel arrangement direction of the linear sensor. In an imaging system that acquires a two-dimensional image,
An image formed by the imaging lens within a light receiving surface of a linear sensor for detecting displacement that is different from the imaging linear sensor arranged so that the imaging surface of the imaging lens and the pixel arrangement direction intersect. The imaging lens is optimal for the imaging linear sensor, based on the difference between the light receiving position coordinate where the contrast of the image becomes the maximum and the coordinate of the pixel position at the point where the imaging surface of the imaging lens of the positional deviation detection linear sensor intersects. When the amount of deviation from the optimal position on the optical axis for image formation on the optical axis is calculated and the linear sensor for position deviation detection cannot detect a gradation step of a predetermined height or more between the pixels, the pixel a light receiving position coordinate where the contrast is greatest between the scan lines that are acquired back in time with respect to the moved image in the direction perpendicular to the array direction, the imaging of the positional shift detection linear sensor From the difference between the coordinates of the pixel position of a point intersecting with the imaging plane of the lens, the imaging lens is calculated an amount of deviation from the optimum position on the optical axis for optimally imaged on the linear sensor the imaging,
A method for detecting a positional deviation of an imaging lens. An image formed by the imaging lens is photoelectrically converted by an imaging linear sensor, and the imaging lens and the imaging linear sensor are mounted and moved in a direction orthogonal to the pixel arrangement direction of the linear sensor to obtain a two-dimensional In the imaging system that acquires images,
An image formed by the imaging lens within a light receiving surface of a linear sensor for detecting displacement that is different from the imaging linear sensor arranged so that the imaging surface of the imaging lens and the pixel arrangement direction intersect. The imaging lens is optimal for the imaging linear sensor, based on the difference between the light receiving position coordinate where the contrast of the image becomes the maximum and the coordinate of the pixel position at the point where the imaging surface of the imaging lens of the positional deviation detection linear sensor intersects. When the amount of deviation from the optimal position on the optical axis for image formation on the optical axis is calculated and the linear sensor for position deviation detection cannot detect a gradation step of a predetermined height or more between the pixels, the pixel a light receiving position coordinate where the contrast is greatest between the scan lines that are acquired back in time with respect to the moved image in the direction perpendicular to the array direction, the imaging of the positional shift detection linear sensor Calculating the amount of deviation from the optimal position on the optical axis for optimal imaging of the imaging lens on the imaging linear sensor, from the difference between the coordinates of the pixel position of the point intersecting the imaging plane of the lens, An image pickup lens position shift correction method, wherein the image pickup lens is moved to the optimum position based on the calculated result. An image formed by the imaging lens is photoelectrically converted by an imaging linear sensor, and the imaging lens and the imaging linear sensor are mounted and moved in a direction orthogonal to the pixel arrangement direction of the linear sensor to obtain a two-dimensional In the imaging system that acquires images,
An image formed by the imaging lens within a light receiving surface of a linear sensor for detecting displacement that is different from the imaging linear sensor arranged so that the imaging surface of the imaging lens and the pixel arrangement direction intersect. The first light receiving position coordinates at which the contrast of the first image is maximized, and the second contrast at which the contrast between the scan lines acquired backwards with respect to the image moved in the direction orthogonal to the pixel array direction is maximized. Means for detecting light receiving position coordinates;
The first or second light receiving position coordinates are selected, and the difference between the selected light receiving position coordinates and the coordinates of the pixel position of the point intersecting with the imaging surface of the imaging lens of the positional deviation detection linear sensor, Means for calculating a deviation amount from an optimum position on the optical axis for the imaging lens to optimally form an image on the imaging linear sensor;
An imaging lens misalignment detection system characterized by the above.   The means for detecting the light receiving position coordinate at which the contrast is maximized is provided for each pixel between a photoelectrically converted image output signal of the positional deviation detection linear sensor and an image signal obtained by delaying the image output signal by a predetermined time. And a means for detecting a pixel arrangement position on the light receiving surface of the linear sensor for a pixel that gives the maximum difference value of the signal obtained from the difference. An imaging lens misregistration detection system as described.   When the means for detecting the light receiving position coordinate at which the contrast is maximized further detects a step having a gradation higher than a predetermined height in the image signal output by photoelectric conversion of the positional deviation detection linear sensor. And means for connecting the output image signal of the linear sensor for detecting displacement to a means for obtaining a difference in signal amplitude for each pixel between the image signal and the image signal obtained by delaying the image output signal by a predetermined time. The imaging lens position shift detection system according to claim 4, further comprising:   The image signal and the image output signal are delayed by a predetermined time when a step having a gradation higher than a predetermined height is detected in the image signal output by photoelectric conversion of the linear sensor for detecting misalignment. The means for connecting the output image signal of the positional deviation detection linear sensor to the means for taking the signal amplitude difference for each pixel from the image signal, and when there is an instruction input from the outside of the means, 5. The imaging lens position shift detection system according to claim 4, further comprising means for starting detection of a step having a gradation of a predetermined height or more in an image signal. An image formed by the imaging lens is photoelectrically converted by an imaging linear sensor, and the imaging lens and the imaging linear sensor are mounted and moved in a direction orthogonal to the pixel arrangement direction of the linear sensor to In an imaging system that acquires a two-dimensional image,
Within the light receiving surface of the positional deviation detection linear sensor different from the imaging linear sensor arranged so that the imaging plane of the imaging lens and the pixel arrangement direction intersect, and the positional deviation detection linear sensor The first light receiving position coordinates at which the contrast of the image formed by the imaging lens is maximized, and between scan lines acquired retrospectively with respect to the image moved in the direction orthogonal to the pixel arrangement direction Means for detecting a second light receiving position coordinate at which the contrast of
The first or second light receiving position coordinates are selected, and the difference between the selected light receiving position coordinates and the coordinates of the pixel position of the point intersecting with the imaging surface of the imaging lens of the positional deviation detection linear sensor, Means for calculating a deviation amount from an optimum position on the optical axis for the imaging lens to optimally form an image on the imaging linear sensor;
Means for moving the imaging lens to the optimum position based on the calculated result;
An image pickup lens position shift correction system comprising:   The means for detecting the light receiving position coordinate at which the contrast is maximized is provided for each pixel between a photoelectrically converted image output signal of the positional deviation detection linear sensor and an image signal obtained by delaying the image output signal by a predetermined time. 8. The apparatus according to claim 7, further comprising: means for taking a difference in signal amplitude; and means for detecting a pixel arrangement position on the light receiving surface of the linear sensor for a pixel that gives a maximum difference value of the signal obtained by taking the difference. Position correction system for imaging lenses.   The means for detecting the coordinates of the light receiving position where the contrast is maximized further detects a step having a gradation higher than a predetermined height in the image signal output by photoelectric conversion of the position deviation detection linear sensor. Means for connecting the output image signal of the linear sensor for detecting displacement to a means for obtaining a difference in signal amplitude for each pixel between the image signal and an image signal obtained by delaying the image output signal by a predetermined time 9. The imaging lens misalignment correction system according to claim 8, further comprising:   The image signal and the image output signal are delayed by a predetermined time when a step having a gradation higher than a predetermined height is detected in the image signal output by photoelectric conversion of the linear sensor for detecting misalignment. The means for connecting the output image signal of the positional deviation detection linear sensor to the means for taking the signal amplitude difference for each pixel from the image signal, and when there is an instruction input from the outside of the means, 9. The system for correcting misalignment of an imaging lens according to claim 8, further comprising means for starting detection of a step having a gradation greater than or equal to a predetermined height in the image signal.

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