JP2017073599A - Image processing apparatus, lens apparatus, imaging apparatus, and imaging apparatus manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing apparatus capable of acquiring a satisfactory image at low costs.SOLUTION: The image processing apparatus acquires evaluation data of a photographic image relating to a first zoom area S101, performs optical adjustment of a lens in the first zoom area S102 to acquire optical adjustment data, determines an image restoration filter relating to a second zoom area on the basis of the acquired evaluation data and optical adjustment data S103, and stores the image restoration filter in a storage part S104. Then, the apparatus uses the image restoration filter to restore the image photographed in the second zoom area.SELECTED DRAWING: Figure 19

Description

  The present invention relates to an image processing apparatus that performs image restoration processing.

  The captured image obtained by the imaging device contains a blur component of the image due to the influence of each aberration such as spherical aberration, coma aberration, field curvature, astigmatism, and light diffraction of the imaging optical system, and deteriorated. Yes. The blur component of the image due to such aberrations means that when there is no aberration and there is no influence of diffraction, the light beam emitted from one point of the subject spreads out on the imaging surface and should be collected again at one point. It is expressed by a point spread function PSF (Point Spread Function).

  An optical transfer function OTF (Optical Transfer Function) obtained by Fourier transforming the point spread function PSF is frequency component information of aberration and is represented by a complex number. The absolute value of the optical transfer function OTF, that is, the amplitude component is referred to as MTF (Modulation Transfer Function), and the phase component is referred to as PTF (Phase Transfer Function). The amplitude component MTF and the phase component PTF are the frequency characteristics of the amplitude component and the phase component, respectively, of image degradation due to aberration, and are expressed by the following equations with the phase component as the phase angle.

PTF = tan ⁻¹ (Im (OTF) / Re (OTF))
Here, Re (OTF) and Im (OTF) represent the real part and the imaginary part of the optical transfer function OTF, respectively. As described above, since the optical transfer function OTF of the imaging optical system deteriorates the amplitude component MTF and the phase component PTF of the image, the deteriorated image is in a state where each point of the subject is asymmetrically blurred like coma. Yes. Further, the chromatic aberration of magnification is generated by shifting the imaging position due to the difference in imaging magnification for each wavelength of light, and acquiring this as, for example, RGB color components according to the spectral characteristics of the imaging device. Accordingly, the image formation position is shifted between RGB, and the image formation position shift for each wavelength, that is, the spread of the image due to the phase shift also occurs in each color component.

  As a method for correcting the deterioration of the amplitude component MTF and the phase component PTF, a method of correcting using the information of the optical transfer function OTF of the imaging optical system is known. This method is called “image restoration” or “image restoration”. Hereinafter, processing for correcting deterioration of a captured image using information of an optical transfer function (OTF) of the imaging optical system is referred to as image restoration processing. Although details will be described later, as one of image restoration methods, there is known a method that convolves an input image with an image restoration filter having an inverse characteristic of an optical transfer function (OTF).

  Patent Document 1 discloses an image processing apparatus that performs image processing while holding a filter coefficient for correcting image degradation. Patent Document 2 includes an optical system adjustment step and a recovery step, and evaluates and classifies the image formation performance of the adjusted image, and performs an image processing for applying a recovery filter to the filter corresponding to the classification. A processing device is disclosed. In the image processing apparatus of Patent Document 2, a good image is obtained by performing an optical adjustment that displaces a part of the optical system and performing an image restoration process using an image restoration filter related to the optical system after the optical adjustment. Can do.

JP 2005-509333 A JP 2012-113690 A

  However, if image degradation after optical adjustment is evaluated for each zoom range and an appropriate image restoration filter is selected, the time required for optical adjustment of the imaging device increases, and the cost of the imaging device increases.

  Therefore, the present invention provides an image processing device, a lens device, an imaging device, and a manufacturing method of the imaging device that can obtain a good image at low cost.

  An image processing apparatus according to one aspect of the present invention is an image related to a second zoom range, which is determined based on evaluation data of a captured image related to the first zoom range and optical adjustment data of a lens in the first zoom range. Storage means for storing a recovery filter; and image recovery means for performing recovery processing on the image shot in the second zoom range using the image recovery filter.

  A lens device according to another aspect of the present invention is determined based on a lens that forms an optical image, evaluation data of a captured image related to the first zoom range, and optical adjustment data of the lens in the first zoom range. Storage means for storing the image restoration filter relating to the second zoom area, and image restoration means for performing restoration processing using the image restoration filter for the image photographed in the second zoom area.

  An imaging apparatus according to another aspect of the present invention includes an imaging element that photoelectrically converts an optical image formed via a lens and outputs image data, evaluation data of a captured image related to a first zoom range, and the first Storage means for storing an image restoration filter relating to the second zoom range determined based on optical adjustment data of the lens in the zoom range, and the image restoration for an image shot in the second zoom range Image restoration means for performing restoration processing using a filter.

  According to another aspect of the present invention, there is provided a method of controlling an imaging apparatus, the step of acquiring evaluation data of a captured image related to a first zoom range, the step of optically adjusting a lens in the first zoom range, and the evaluation data. Determining an image restoration filter for the second zoom range based on the optical adjustment data of the lens.

  Other objects and features of the invention are described in the following embodiments.

  According to the present invention, it is possible to provide an image processing device, a lens device, an imaging device, and a manufacturing method of the imaging device that can obtain a good image at low cost.

It is a block diagram of the imaging device in this embodiment. It is a flowchart of the image processing method in this embodiment. It is a block diagram of the image processing system in this embodiment. It is explanatory drawing of the image restoration filter in this embodiment. It is explanatory drawing of the image restoration filter in this embodiment. It is explanatory drawing of the point spread function PSF in this embodiment. It is explanatory drawing of the amplitude component and phase component of the optical transfer function in this embodiment. It is sectional drawing of the optical system (1st optical system) in this embodiment. It is sectional drawing of another optical system (2nd optical system) in this embodiment. In this embodiment, it is a longitudinal aberration diagram of the first optical system at the wide angle end. In this embodiment, it is a longitudinal aberration diagram of the first optical system at an intermediate position. In this embodiment, it is a longitudinal aberration diagram of the first optical system at the telephoto end. In this embodiment, it is a lateral aberration diagram regarding the error of the lens in the 2nd lens group of the 1st optical system in a telephoto end. In this embodiment, it is a lateral aberration diagram after optical adjustment of the lenses in the second lens group of the first optical system at the wide angle end. In this embodiment, it is a longitudinal aberration diagram of the second optical system at the wide angle end. In this embodiment, it is a longitudinal aberration diagram of the second optical system at an intermediate position. In this embodiment, it is a longitudinal aberration diagram of the second optical system at the telephoto end. It is a block diagram of the manufacturing apparatus of the imaging device in this embodiment. It is a flowchart which shows the manufacturing method of the imaging device in this embodiment. It is explanatory drawing of the manufacture error adjustment (optical adjustment) of the 1st optical system in this embodiment. It is explanatory drawing of the manufacture error adjustment (optical adjustment) of the 2nd optical system in this embodiment. It is explanatory drawing of the optical characteristic before and behind the optical adjustment of the 2nd optical system in this embodiment. It is explanatory drawing of the production | generation method of the image restoration filter after the optical adjustment of the 2nd optical system in this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, definitions of terms and image restoration processing (image processing method) described in the present embodiment will be described.

[Input image]
The input image is a digital image (photographed image) obtained by receiving light with an image pickup device via an image pickup optical system, and is deteriorated by an optical transfer function OTF due to aberration of the image pickup optical system including a lens and various optical filters. doing. The imaging optical system can be configured using not only a lens but also a mirror (reflection surface) having a curvature.

  The color component of the input image has information on RGB color components, for example. As the color component, other commonly used color spaces such as brightness, hue, and saturation expressed in LCH, luminance expressed in YCbCr, and color difference signals can be selected and used. As other color spaces, XYZ, Lab, Yuv, and JCh can be used. Further, a color temperature may be used.

  The input image and the output image can be accompanied by shooting conditions such as the focal length of the lens, aperture value, shooting distance, and various correction information for correcting this image. When the image is transferred from the imaging apparatus to another image processing apparatus and correction processing is performed, it is preferable to add information regarding shooting conditions and correction to the captured image as described above. As another delivery method of information regarding imaging conditions and correction, the imaging apparatus and the image processing apparatus may be directly or indirectly connected to be delivered.

[Image recovery processing]
Next, an outline of the image restoration process will be described. Degraded image (degraded captured image) is g (x, y), original image is f (x, y), and point spread function PSF which is a Fourier pair of the optical transfer function OTF is h (x, y). Then, the following equation (1) is established.

g (x, y) = h (x, y) * f (x, y) (1)
Here, * is convolution (convolution integration, sum of products), and (x, y) are coordinates on the captured image.

  Moreover, if Formula (1) is Fourier-transformed and converted into a display format on the frequency plane, Formula (2) represented by the product for each frequency is obtained.

G (u, v) = H (u, v) .F (u, v) (2)
Here, H is an optical transfer function OTF obtained by Fourier transforming the point spread function PSF (h), and G and F are obtained by Fourier transforming the degraded image g and the original image f, respectively. Function. (U, v) is a coordinate on a two-dimensional frequency plane, that is, a frequency.

  In order to obtain the original image f from the photographed degraded image g, both sides may be divided by the optical transfer function H as shown in the following equation (3).

G (u, v) / H (u, v) = F (u, v) (3)
Then, F (u, v), that is, G (u, v) / H (u, v) is subjected to inverse Fourier transform to return to the actual surface, whereby the original image f (x, y) is obtained as a restored image. can get.

When R is the result of inverse Fourier transform of H− ¹ , the original image f (x, y) is similarly obtained by performing convolution processing on the actual image as in the following equation (4). Can be obtained.

g (x, y) * R (x, y) = f (x, y) (4)
Here, R (x, y) is called an image restoration filter. When the image is a two-dimensional image, the image restoration filter R generally has a tap (cell) corresponding to each pixel of the image and has a two-dimensional filter value distribution. In general, the recovery accuracy improves as the number of taps (cells) of the image recovery filter R increases. Therefore, the number of taps that can be realized is set according to the required image quality, image processing capability, aberration characteristics, and the like. Since the image restoration filter R needs to reflect at least aberration and diffraction characteristics, the image restoration filter R is different from a conventional edge enhancement filter (high-pass filter) of about 3 taps each in horizontal and vertical directions. Since the image restoration filter R is set based on the optical transfer function OTF, it is possible to correct both the amplitude component and the deterioration of the phase component with high accuracy.

  In addition, since an actual image contains a noise component, using the image restoration filter R created by taking the complete inverse of the optical transfer function OTF as described above, the noise component is greatly amplified along with the restoration of the deteriorated image. It will be. This is because the MTF is raised so that the MTF (amplitude component) of the optical system is returned to 1 over the entire frequency in a state where the amplitude of noise is added to the amplitude component of the image. The MTF, which is amplitude degradation due to the optical system, returns to 1, but at the same time, the noise power spectrum also rises. As a result, the noise is amplified according to the degree to which the MTF is raised (recovery gain).

  Therefore, when noise is included, a good image cannot be obtained as a viewing image. This is expressed by the following formulas (5-1) and (5-2).

G (u, v) = H (u, v) .F (u, v) + N (u, v) (5-1)
G (u, v) / H (u, v) = F (u, v) + N (u, v) / H (u, v) (5-2)
Here, N is a noise component.

  For an image including a noise component, there is a method of controlling the degree of recovery according to the intensity ratio SNR between the image signal and the noise signal, for example, as in the Wiener filter expressed by the following formula (6).

Here, M (u, v) is the frequency characteristic of the Wiener filter, and | H (u, v) | is the absolute value (MTF) of the optical transfer function OTF. In this method, for each frequency, the smaller the MTF, the smaller the recovery gain (degree of recovery), and the larger the MTF, the larger the recovery gain. In general, since the MTF of the imaging optical system is high on the low frequency side and low on the high frequency side, this method substantially reduces the recovery gain on the high frequency side of the image.

  Subsequently, the image restoration filter will be described with reference to FIGS. 4 and 5. The number of taps of the image restoration filter is determined according to the aberration characteristics of the imaging optical system and the required restoration accuracy. The image restoration filter in FIG. 4 is, for example, an 11 × 11 tap two-dimensional filter. In FIG. 4, values in each tap are omitted, but a cross section of this image restoration filter is shown in FIG. The distribution of the values (coefficient values) of each tap of the image restoration filter has a function of returning a signal value or a pixel value (PSF) spatially spread due to aberration to an original one point ideally.

  Each tap of the image restoration filter is subjected to convolution processing (convolution integration, product sum) in the image restoration processing corresponding to each pixel of the image. In the convolution process, in order to improve the signal value of a predetermined pixel, the pixel is matched with the center of the image restoration filter. Then, the product of the signal value of the image and the value of each tap of the filter is calculated for each corresponding pixel of the image and the image restoration filter, and the sum is replaced with the signal value of the central pixel.

  Next, characteristics of the image restoration in the real space and the frequency space will be described with reference to FIGS. 6 and 7. 6A and 6B are explanatory diagrams of the point spread function PSF. FIG. 6A shows the point spread function PSF before image restoration, and FIG. 6B shows the point spread function PSF after image restoration. . FIG. 7 is an explanatory diagram of the amplitude component MTF (FIG. 7A) and the phase component PTF (FIG. 7B) of the optical transfer function OTF. In FIG. 7A, the broken line (A) indicates the MTF before image recovery, and the alternate long and short dash line (B) indicates the MTF after image recovery. In FIG. 7B, the broken line (A) indicates the PTF before image recovery, and the alternate long and short dash line (B) indicates the PTF after image recovery. As shown in FIG. 6A, the point spread function PSF before image restoration has an asymmetric spread, and the phase component PTF has a non-linear value with respect to the frequency due to this asymmetry. Since the image restoration process amplifies the amplitude component MTF and corrects the phase component PTF to be zero, the point spread function PSF after the image restoration has a symmetrical and sharp shape.

  As described above, the image restoration filter can be obtained by performing inverse Fourier transform on a function designed based on the inverse function of the optical transfer function OTF of the imaging optical system. The image restoration filter used in the present embodiment can be appropriately changed. For example, the above-described Wiener filter can be used. When using the Wiener filter, it is possible to create an image restoration filter in real space that is actually convolved with the image by performing inverse Fourier transform on Equation (6). Further, the optical transfer function OTF also changes in accordance with the image height (image position) of the imaging optical system even in one imaging state (imaging condition). For this reason, the image restoration filter is changed and used according to the image height.

  Next, with reference to FIG. 1, the imaging apparatus according to the present embodiment will be described. FIG. 1 is a configuration diagram of an imaging apparatus 100 in the present embodiment. The imaging apparatus 100 can generate a recovered image (output image) from a captured image (input image) by performing image recovery processing using an image recovery filter.

  In the imaging apparatus 100, a light beam from a subject (not shown) forms an image on the imaging element 102 via the imaging optical system 101. The imaging optical system 101 includes a variable power lens (not shown), a diaphragm 101a, and a focus lens 101b. By moving the zoom lens in the optical axis direction, zooming that changes the focal length of the imaging optical system 101 is possible. The aperture 101a adjusts the amount of light reaching the image sensor 102 by increasing or decreasing the aperture diameter. Since the focus lens 101b performs focus adjustment according to the subject distance, the position of the focus lens 101b in the optical axis direction is controlled by an unillustrated autofocus (AF) mechanism or manual focus mechanism.

  The imaging element 102 includes a CCD sensor, a CMOS sensor, and the like, photoelectrically converts a subject image (optical image) formed via the imaging optical system 101, and outputs image data (analog image signal). The subject image formed on the image sensor 102 is converted into an electrical signal and output to the A / D converter 103. The A / D converter 103 converts the input electric signal (analog image signal) into a digital image signal and outputs the digital image signal to the image processing unit 104.

  The image processing unit 104 (image processing unit) includes an image generation unit 104a and an image recovery / distortion correction unit 104b (image recovery unit and distortion correction unit). The image generation unit 104 a generates an input image (color input image) by performing various types of image processing on the digital image signal input to the image processing unit 104. The image recovery / distortion correction unit 104b performs image recovery processing and geometric transformation processing (distortion correction processing) on the input image. In the present embodiment, the configuration from the image sensor 102 to the image generation unit 104a (the image sensor 102, the A / D converter 103, and the image generation unit 104a) constitutes an imaging system.

  The image recovery / distortion correction unit 104b obtains information (imaging condition information) regarding the state (imaging state, that is, imaging conditions) of the imaging optical system 101 from the state detection unit 107. The imaging conditions include the focal length (zoom position) of the imaging optical system 101, the aperture diameter (aperture value or F number) of the stop 101a, the focus lens position (subject distance), and the like. The state detection unit 107 can acquire information related to shooting conditions (shooting condition information) from the system controller 110. Further, at least a part of the information related to the imaging condition can be acquired from the imaging optical system control unit 106 that controls the imaging optical system 101.

  The image restoration / distortion correction unit 104b selects an image restoration filter corresponding to the shooting condition from the storage unit 108 (storage means such as a memory), and performs image restoration processing on the input image. The image restoration / distortion correction unit 104b selects a geometric conversion condition corresponding to the shooting condition from the storage unit 108, and performs a geometric conversion process on the image that has undergone the image restoration process. The image processing apparatus according to the present embodiment includes, for example, a state detection unit 107, an image restoration / distortion correction unit 104b, and a storage unit 108.

  The output image (recovered image) processed by the image processing unit 104 is recorded on the image recording medium 109 in a predetermined format. The display unit 105 displays an image obtained by performing a predetermined display process on the image after the image processing in the present embodiment. Alternatively, an image subjected to simple processing for high-speed display may be displayed. A series of control in the imaging apparatus 100 is performed by the system controller 110. Further, mechanical driving of the imaging optical system 101 (the diaphragm 101a and the focus lens 101b) is performed by the imaging optical system control unit 106 based on an instruction from the system controller 110.

  In the present embodiment, the imaging optical system 101 is configured integrally with the imaging apparatus main body having the imaging element 102, but is not limited to this. The present embodiment can also be applied to an imaging apparatus having an imaging apparatus body and an imaging optical system (lens apparatus) that can be attached to and detached from the imaging apparatus body.

  Next, an image processing method according to this embodiment will be described with reference to FIG. FIG. 2 is a flowchart showing an image processing method (image restoration processing and geometric transformation processing) in the present embodiment. The image processing method of the present embodiment is mainly executed by the image processing unit 104 (an image processing device including the image restoration / distortion correction unit 104b). The image processing unit 104 is configured by an image processing computer and executes image processing according to a computer program.

  First, in step S <b> 1, the image processing unit 104 acquires an image (input image) generated based on the image data output from the image sensor 102. Subsequently, in step S <b> 2, the image processing unit 104 acquires shooting condition information from the state detection unit 107. In the present embodiment, the photographing conditions are three conditions, that is, the zoom position, the aperture diameter of the stop 101a, and the subject distance, but are not limited thereto. When a lens device (exchangeable lens) that can be attached to and detached from the imaging device main body (camera main body) is used, the shooting conditions include a lens ID and a camera ID. Information regarding the imaging conditions can be acquired directly from the imaging device, or can be acquired from information attached to the image.

  Subsequently, in step S3, the image processing unit 104 determines whether or not to perform a recovery process on the input image based on the imaging condition acquired in step S2. When the image processing unit 104 determines to perform the recovery process, the process proceeds to step S4. On the other hand, when the image processing unit 104 determines not to perform the recovery process, the process proceeds to step S7.

  In step S4, the image processing unit 104 selects or generates an image restoration filter corresponding to the photographing condition acquired in step S2. The image restoration filter is stored for each photographing condition based on the optical transfer function (OTF). The image restoration filter is stored for each position (image height position) in the input image. If necessary, the image processing unit 104 can generate an image restoration filter based on the optical transfer function (OTF). Subsequently, in step S5, the image processing unit 104 performs image restoration processing by convolving the image restoration filter determined in step S4 with respect to the input image. In step S6, the image processing unit 104 generates a restored image.

  Subsequently, in step S7, the image processing unit 104 performs various necessary processes other than the recovery process on the recovered image or the input image. Then, the image processing unit 104 outputs the recovered image or input image after processing as an output image.

  In the present embodiment, the storage unit 108 does not store image restoration filters for all shooting conditions (that is, the storage unit 108 stores only image restoration filters for a part of all shooting conditions). The image processing unit 104 does not perform a recovery process on an image (input image) captured under imaging conditions corresponding to an image recovery filter that is not stored in the storage unit 108. The image restoration filter is generated based on a point spread function (PSF) relating to each imaging condition of the imaging optical system. For example, in order to recover an asymmetrical aberration such as coma, it is necessary to perform a recovery process using a two-dimensional filter as an image recovery filter. For this reason, one-dimensional correction processing such as distortion correction cannot be performed, the data amount of the image restoration filter becomes enormous, and the storage capacity of the storage unit 108 needs to be increased. Also, it takes a lot of time to execute the recovery process. Accordingly, it is preferable that the image capturing filter is not stored in the storage unit 108 and the recovery process is not performed for a shooting condition that does not require the recovery process. However, for an imaging optical system that preferably performs recovery processing for all imaging conditions, the storage unit 108 may store image recovery filters for all imaging conditions.

  Further, if the optical performance is sufficiently corrected by the optical adjustment at the adjustment position in the manufacturing process (optical adjustment process) of the imaging apparatus 100 (or the lens apparatus), it is not necessary to hold the image restoration filter related to the adjustment position. That is, by holding the image restoration filter only for the non-adjustment position, the amount of data to be stored in the storage unit 108 can be reduced.

  Next, the image processing system in the present embodiment will be described with reference to FIG. FIG. 3 is a configuration diagram of the image processing system 300 in the present embodiment. In FIG. 3, an image processing apparatus 301 is a computer device equipped with image processing software 306 for causing a computer (information processing apparatus) to execute the image processing method of the present embodiment. The image processing apparatus 301 has the same functions as the image generation unit 104a, the image recovery / distortion correction unit 104b, and the storage unit 108 described with reference to FIG. The imaging device 302 is an imaging device such as a camera, a microscope, an endoscope, or a scanner. The storage medium 303 is a storage unit that stores captured images, such as a semiconductor memory, a hard disk, or a server on a network.

  Moreover, this embodiment is implement | achieved also by performing the following processes. That is, software (program) that realizes the functions of the above-described embodiments is supplied to and stored in a system or apparatus via various storage media 307 such as a network or a CD-ROM. Then, a computer (or CPU, MPU, etc.) of the system or apparatus reads and executes the program.

  The image processing apparatus 301 acquires captured image data from the imaging device 302 or the storage medium 303, and outputs image data (output image) subjected to predetermined image processing to any one of the output device 305, the imaging device 302, and the storage medium 303. Output to one or more. Further, the output destination can be stored in a storage unit built in the image processing apparatus 301. The output device 305 is a printer, for example.

  A display device 304 that is a monitor is connected to the image processing apparatus 301. Therefore, the user can perform the image processing work through the display device 304 and evaluate the corrected image. The image processing software 306 performs image restoration processing (image processing method) according to the present embodiment, and performs development and other image processing as necessary.

  In the present embodiment, the contents of data for performing image processing (correction information such as shooting conditions) and the exchange of data between devices are preferably attached to individual image data. By attaching necessary correction information to the image data, correction processing (image restoration processing) can be appropriately performed in any device equipped with the image processing apparatus of the present embodiment.

  For an optical system (imaging optical system) having no manufacturing error, it is conceivable to use an image processing filter created based on a design value at the time of image restoration processing. However, in an actual optical system, curvature of field and one-sided blur are caused by decentering or tilting of each lens group constituting the optical system, or by decentering or tilting between each lens group. For this reason, the actual optical system has an aberration different from the design value.

  When the aberration of the optical system is large, the image restoration process cannot be executed accurately. For this reason, there is known a method of reducing one-sided blur due to a manufacturing error by performing an optical adjustment for displacing a part of lenses constituting the lens group (for example, in a direction perpendicular to the optical axis). The lens to be displaced during the optical adjustment is usually a lens in which a lens (lens group) suitable for optical adjustment is placed upward on the tool and placed on the upper side of the tool in consideration of the simplicity of the optical adjustment process. By displacing the lens, optical adjustment with a tool can be performed at low cost.

  Since the lens used for optical adjustment is adjusted at a site different from the cause of production error, residual aberrations such as coma may occur due to optical adjustment. By correcting the aberration caused by the optical adjustment by the image restoration process, it is possible to improve the function of the optical system. However, if it is attempted to determine (select) an image restoration filter by evaluating image degradation after optical adjustment, a process for evaluating the image after optical adjustment is required, and time is required for optical adjustment.

  Therefore, in the present embodiment, at the time of optical adjustment, an image before optical adjustment is evaluated to estimate the cause of image degradation (acquisition data of the image is acquired), and an image restoration filter is determined. In this embodiment, instead of evaluating the image before optical adjustment, the optical adjustment data, that is, the optical adjustment amount (lens displacement amount) and the optical adjustment direction (lens displacement direction) are detected, and the image degradation is detected. The cause can also be estimated. As described above, in this embodiment, the image restoration filter determined based on the evaluation data of the image before the optical adjustment and the optical adjustment data is selected, and the image restoration for correcting the aberration causing the image deterioration is performed.

  Next, the configuration of the optical system (imaging optical system) in the present embodiment will be described with reference to FIGS. 8 and 10 to 12. FIG. 8 is a cross-sectional view of the optical system (first optical system) in the present embodiment. A), B), and C) in FIG. 8 respectively show the wide-angle end, the intermediate position, and the telephoto end. The configuration of the optical system (first optical system) in FIG. 8 is as shown in Numerical Example 1. 10, 11, and 12 are longitudinal aberration diagrams of the first optical system at the wide-angle end, the intermediate position, and the telephoto end, respectively. In each aberration diagram of FIGS. 10 to 12, Fno is an F value and ω is a half angle of view. From the left side of each figure, spherical aberration, astigmatism, distortion, and chromatic aberration (magnification chromatic aberration) are shown. Regarding spherical aberration, aberrations for d-line and g-line are shown. Regarding astigmatism, field curvatures at sagittal image surface ΔS and meridional image surface ΔM are shown. These points are the same for each aberration diagram described later.

  The first optical system has a zoom ratio of about 3 times, and particularly corresponds to a sensor larger than a normal compact digital camera. The first optical system includes three groups of a negative first lens unit L1, a positive second lens unit L2, and a negative third lens unit L3 in order from the object side to the image side. In zooming from the wide-angle end to the telephoto end, the first optical system has a locus on which the first lens unit L1 is convex toward the image side, and corrects image plane fluctuations due to zooming. The second lens unit L2 moves toward the object side and is responsible for main magnification. The third lens unit L3 draws a locus close to the second lens unit L2, but corrects the image plane variation in the intermediate region by changing the distance between the second lens unit L2 and air. By moving the third lens unit L3 toward the image side, a focusing operation on a short-distance object is possible. The stop SP is disposed between the second lens unit L2 and the third lens unit L3.

  The first lens unit L1 is composed of three lenses in order from the object side to the image side: a negative meniscus lens having a convex surface on the object side, a biconcave negative lens, and a positive meniscus lens having a convex surface on the object side. The second lens unit L2 is composed of four lenses in order from the object side to the image side: a positive lens having a strong convex surface on the object side, a cemented lens in which a positive lens and a negative lens are cemented, and a positive lens having a strong convex surface on the image side. ing. The third lens unit L3 includes, in order from the object side to the image side, a positive meniscus lens having a convex surface on the image side and a negative meniscus lens having a convex surface on the image side. Camera shake correction can be performed by displacing the entire second lens unit L2 in a direction substantially perpendicular to the optical axis OA. In this embodiment, adjustment of one manufacturing error (optical adjustment) is performed by displacing one positive lens closest to the object side of the second lens unit L2 in a direction substantially perpendicular to the optical axis OA. In actual optical adjustment, even if it is decentered in parallel with the optical axis OA, a tilt of about 5 minutes or less may occur with respect to the direction perpendicular to the optical axis. In particular, when the lens surface is decentered along the lens barrel holding portion, the lens surface may be decentered along with the curvature of the lens surface to be contacted, but even in this case, the tilt is configured to be within 5 minutes. The

  In the first optical system, the second lens group L2 is a group responsible for main image formation, and corrects spherical aberration and coma aberration in the entire zoom range. The positive lens arranged closest to the object side in the second lens unit L2 is converged with a divergent light beam emitted from the first lens unit L1 with a strong power and is emitted to the subsequent lens side. It has the property of greatly affecting coma aberration and field curvature when the lens is decentered. In the manufacturing process of the entire optical system, due to decentering and tilting of a plurality of lenses constituting the second lens unit L2, and decentering and tilting between the lens units, a piece caused by asymmetry such as spherical aberration, coma aberration, and field curvature Blur occurs.

  The leading lens of the second lens unit L2 is highly sensitive to aberrations. For this reason, since it is suitable for correcting the deterioration of the optical performance by adjusting the aberration generated in other parts of the entire optical system during the manufacturing process, it is possible to adjust the eccentricity. For example, an adjustment error generated in the second lens group L2 can be adjusted by performing adjustment on the tool before the second lens group L2 is incorporated into the optical system. Further, when the second lens group L2 is incorporated after the subsequent lens group (third lens group L3) of the second lens group L2 is incorporated, and the leading lens of the second lens group L2 is adjusted, the second lens group L2 It is possible to correct aberrations caused by decentering or tilting with the subsequent lens group.

  This adjustment includes a method for adjusting the imaging performance and contrast in the vicinity of the central portion, and a method for adjusting so that one side blur in the peripheral portion is reduced. With these adjustments, the optical performance can be improved at the zoom position where the optical adjustment is performed (first zoom range) because the optical adjustment is performed according to the degree of manufacturing degradation of the first zoom range.

  On the other hand, at a zoom position (second zoom range) other than the zoom range (first zoom range) for optical adjustment, the degree of image degradation due to eccentricity or tilting that causes an error is referred to as the adjustment zoom range (first zoom range). Is different. For this reason, an error remains even after optical adjustment. For example, when the center contrast at which the error due to the decentration component of the lens in the second lens unit L2 occurs at the telephoto end is corrected to near the design value, the central frame remains in the wide to middle range due to optical adjustment, Astigmatism may occur. The zoom range where the error occurs (second zoom range) is different from the zoom range where the optical adjustment is performed (first zoom range). For this reason, when the telephoto end is corrected to a value close to the design value, coma aberration occurs due to decentration due to optical adjustment in the wide to middle range, and the contrast of the peripheral portion may decrease as shown in FIG.

  Next, the configuration of the optical system (imaging optical system) in the present embodiment will be described with reference to FIGS. 9 and 15 to 17. FIG. 9 is a cross-sectional view of another optical system (second optical system) in the present embodiment. A), B), and C) of FIG. 9 show the states at the wide-angle end, the intermediate position, and the telephoto end, respectively. The configuration of the optical system (second optical system) in FIG. 9 is as shown in Numerical Example 2. FIGS. 15, 16, and 17 are longitudinal aberration diagrams of the second optical system at the wide-angle end, the intermediate position, and the telephoto end, respectively.

  The second optical system has a zoom ratio of about 4 times, particularly bright in the entire zoom range from the wide-angle end to the telephoto end, and has a small aperture value Fno. The second optical system includes, in order from the object side to the image side, a positive first lens unit L1, a negative second lens unit L2, a positive third lens unit L3, a negative fourth lens unit L4, and a positive first lens unit L4. It consists of five lens units L5. During zooming from the wide-angle end to the telephoto end, the first lens unit L1 moves toward the image side by a minute amount and then moves toward the object side. The second lens unit L2 moves to the image side. The third lens group L3 and the fourth lens group L4 move to the object side. The stop SP is disposed between the second lens unit L2 and the third lens unit L3, and moves so that the air gap between the stop SP and the third lens unit L3 decreases during zooming. The air space between the third lens unit L3 and the fourth lens unit L4 moves so as to increase during zooming. The fifth lens unit L5 moves nonlinearly by a minute amount.

  In the second optical system, the first lens unit L1 includes two lenses, a negative lens and a positive lens. The second lens unit L2 includes three lenses: a negative meniscus lens having a convex surface on the object side, a biconcave negative lens, and a positive meniscus lens having a convex surface on the object side. The third lens unit L3 includes five lenses including a biconvex positive lens, a cemented lens of a negative lens having a concave surface on the object side and a positive lens, and a cemented lens of a negative lens having a convex surface on the object side and a biconvex positive lens. Yes. The fourth lens unit L4 includes a positive lens having a convex surface on the object side and a negative lens having a concave surface on the image side. The fifth lens unit L5 includes one positive lens having a convex surface on the object side. An image stabilization mechanism (not shown) can correct camera shake by shifting the entire third lens unit L3 in a direction substantially perpendicular to the optical axis OA. Focusing can be performed by retracting the fourth lens unit L4 toward the object side or extending the fifth lens unit L5. In the present embodiment, the manufacturing error is adjusted (optical adjustment) by displacing the lens closest to the object side of the third lens unit L3 in a direction substantially perpendicular to the optical axis OA. In the second optical system, focusing is performed by the fourth lens unit L4 or the fifth lens unit L5, but a part of the first lens unit L1, the second lens unit L2, or the third lens unit L3 is used. You may go.

  Here, regarding the second optical system, generation of an image restoration filter after optical adjustment will be described. The second optical system is composed of five groups: positive, negative, positive, negative, and positive. In the second optical system, aberration correction is performed satisfactorily even with bright Fno, and therefore the number of lenses constituting the third lens unit L3 responsible for main image formation is large. In the manufacturing process of the entire optical system, due to the decentering and tilting of a plurality of lenses constituting the third lens unit L3 and the decentering and tilting between the lens units, a piece caused by asymmetry such as spherical aberration, coma aberration, and field curvature Blur occurs. The leading lens of the third lens unit L3 is highly sensitive to aberrations. For this reason, it is suitable for correcting the deterioration of the optical performance by adjusting the aberration generated in other parts of the entire optical system during the manufacturing process, and it is possible to adjust the eccentricity. For example, before the third lens group L3 is incorporated into the optical system, an assembling error occurring in the third lens group L3 can be adjusted by performing optical adjustment on the tool. Further, when the third lens group L3 is incorporated after the lens group subsequent to the third lens group L3 (fourth and fifth lens groups L4, L5) is incorporated, and the leading lens of the third lens group L3 is adjusted, the third lens It is possible to correct aberrations caused by decentering or tilting of the group L3 and the subsequent lens group.

  This adjustment includes a method of adjusting the imaging performance in the vicinity of the center so that the contrast is increased, and a method of adjusting so that one side blur in the peripheral portion is reduced. In the state to be adjusted by these adjustments, the optical performance can be improved because the adjustment is performed according to the degree of manufacturing deterioration of the state. In a zoom range (second zoom range) other than the zoom range (first zoom range) in which optical adjustment is performed, the degree of image deterioration due to eccentricity or tilting that causes an error differs from the adjustment position. For this reason, an error remains even after optical adjustment.

  FIG. 22 is an explanatory diagram of optical characteristics before and after optical adjustment with respect to the second optical system, and focus characteristics in the MTF before and after optical adjustment with respect to the second optical system at the wide-angle end (Wide) and the telephoto end (Tele). Is schematically shown. Here, regarding the decrease in the central MTF at the telephoto end, the central MTF is corrected by decentering the leading lens of the third lens unit L3 in the direction in which the central coma aberration is corrected. At this time, at the wide-angle end, the deterioration characteristics of the peripheral performance due to the error in the third lens unit L3 remain, and there is little change due to the optical adjustment, which is close to the characteristics before the optical adjustment.

  FIG. 23 is an explanatory diagram of a method for generating an image restoration filter after optical adjustment for the second optical system. Based on the characteristics before adjustment at the telephoto end, the characteristics after adjustment at the wide angle end are predicted to restore the image. It shows how to generate a filter. In the second optical system, the lenses in the third lens unit L3 are in a state containing a decentered component due to manufacturing errors. The third lens unit L3 includes five lenses. When the cemented lens on the image side is decentered, the center MTF is reduced due to central coma at the telephoto end, and one-sided blur occurs. On the other hand, at the wide-angle end, although there is little performance degradation at the center, lateral chromatic aberration occurs in one direction at the peripheral portion, so the MTF decreases at one image height. When the first lens of the third lens unit L3 is adjusted on the telephoto side, the optical performance is improved for both the center frame and the one-sided blur, but the one-sided blur before the optical adjustment is improved at the wide-angle end, but the chromatic aberration of one image height is Not improved. The performance after the optical adjustment at the wide angle end can be predicted by estimating the original cause of deterioration from the image before the optical adjustment at the telephoto end and the adjustment data (adjustment amount) of the adjustment lens.

  By applying the image restoration filter to the predicted image, an appropriate image restoration filter can be selected without evaluating the wide-angle end image. As a method of measuring the one-sided blur state at the telephoto end, a method of evaluating the asymmetric component of the PSF shape in the peripheral portion of the screen at an image height near 50% to 90% of the maximum image height equidistant from the center can be considered. Another method is to evaluate the direction and amount (color blur value) of color blur (chromatic aberration) at the periphery of the screen at an image height near 50% to 90% of the maximum image height equidistant from the center. The state of one-sided blur can be measured.

  In an imaging apparatus capable of color imaging, a color that does not originally exist around a bright portion of an image may be generated as a color blur due to chromatic aberration of an imaging optical system that forms an optical image of a subject on an imaging element. In visible light color imaging with an imaging device, color blur tends to occur in areas away from green, which is the central wavelength of the imaging optical system, and blue, red, or a purple artifact that is a mixture of both causes blur, and color blur or purple It is called fringe. When a manufacturing error occurs due to decentration of the lens or the like, chromatic aberration caused by decentration can be estimated by measuring the amount of color blur (high aberration) in the four directions on the periphery of the screen.

  Based on the estimated chromatic aberration, it can be estimated which lens is decentered (displaced), and the residual aberration due to the factor can be estimated over the entire zoom range. For example, in the case of the second optical system, it is conceivable to adjust the third lens unit L3 in a unit state. However, the third lens group L3 may be adjusted based on the one-side blur component measured and evaluated and the sensitivity due to the eccentricity of each lens in the design. It is possible to estimate the lens and the amount of decentration that caused the one-sided blur in the lens unit L3. As another method for estimating the cause of one-sided blur, a manufacturing error factor at the time of incorporation is generated at random, the residual aberration of 100 or more error lenses is calculated, and the lens that causes deterioration from the distribution of calculated evaluation values And the amount of eccentricity can be estimated. When the amount of eccentricity of the lens that caused the deterioration is known, when the lens is adjusted with the first lens in the third lens unit L3, the remaining lens at the other position remains due to the difference in sensitivity of each lens at each position. The type and amount of aberration can be estimated. A plurality of image restoration filters in which the residual aberration is patterned from a plurality of error lenses calculated in advance are prepared, and an image restoration filter is selected from an evaluation value such as a PSF shape in the manufacturing process to select which filter is to be applied. Can do.

  As described above, in the present embodiment, the image restoration relating to the wide angle end (second zoom range) is performed based on the image (image evaluation data) and the optical adjustment data (optical adjustment amount) acquired at the telephoto end (first zoom range). Select a filter. Thereby, it is possible to reduce the man-hours for optical adjustment and manufacture the lens at low cost.

  FIG. 13 is a lateral aberration diagram regarding the error of the lenses in the second lens group of the first optical system at the telephoto end. FIG. 14 is a lateral aberration diagram after optical adjustment of the lenses in the second lens group of the first optical system at the wide-angle end. For example, when the center contrast is corrected to near the design value at which the error due to the decentration component of the lens in the second lens unit L2 occurs at the telephoto end, the center frame remains in the wide to middle range by optical adjustment, Astigmatism may occur. Since the zoom state location for adjusting the state in which the error occurs is different, if correction is made to near the design value at the telephoto end, coma aberration occurs due to decentering in the wide to middle range, and as shown in FIG. The contrast of the part may be lowered. With respect to such a lens, a reduction in contrast due to optical adjustment can be compensated by performing an image restoration process. In this case, it is preferable to prepare a plurality of types of image restoration filters according to the residual aberration amount after optical adjustment, and selectively adapt which image restoration filter is used.

  In the present embodiment, as a first selection method for a plurality of types of image restoration filters, an image acquired at an optical adjustment location (first zoom range) is evaluated, and a zoom range (second range) other than the optical adjustment location is determined based on the remaining aberration. There is a method of selecting an image restoration filter by predicting a residual aberration related to the zoom range. As a second filter selection method, there is a method in which the displacement amount of the optical adjustment lens is measured, and the aberration remaining in the zoom region other than the adjustment portion is predicted and selected from the displacement amount. With this method, it is possible to select an image restoration filter that instantly adapts after optical adjustment, and it is possible to reduce the number of optical adjustment steps and reduce the manufacturing cost required for optical adjustment incorporation.

  FIG. 20 is an explanatory diagram of the manufacturing error adjustment (optical adjustment) of the first optical system, and in order from the object side to the image side, the negative first lens unit L1, the positive second lens unit L2, and the negative first lens unit. The adjustment method of the 1st optical system which consists of 3 lens group L3 is shown. In FIG. 20, the dotted line and the alternate long and short dash line indicate portions where one-sided blur and decentration coma are generated due to manufacturing errors, respectively. In the portion indicated by the dotted line, one-sided blur and peripheral coma aberration occur due to decentering or tilting when the lens group constituting the second lens group L2 is assembled. The portion indicated by the alternate long and short dash line indicates the entirety of the second lens unit L2 and the third lens unit L3, and it is also one piece due to relative decentration or tilting between the second lens unit L2 and the third lens unit L3. Blur occurs. These single-blurring errors can be adjusted to a state where there is little single-blurring by decentering (displacement) the leading lens indicated by the solid line in the second lens unit L2 in a direction substantially perpendicular to the optical axis OA.

  Next, with respect to the second optical system, a typical method for generating an image restoration filter in this embodiment will be described. The second optical system includes, in order from the object side to the image side, a positive first lens unit L1, a negative second lens unit L2, a positive third lens unit L3, a negative fourth lens unit L4, and a positive first lens unit L4. The zoom lens includes five lens units L5. During zooming from the wide-angle end to the telephoto end, each unit moves and the third lens unit L3 moves to the object side. In the second optical system, one positive lens closest to the object side of the third lens unit L3 is an adjustment lens (a lens to be optically adjusted). In this lens, a step of adjusting the third lens group L3 on the tool or adjusting the adjustment lens in a state in which the third to fifth lens groups L3 to L5 are incorporated can be considered. When adjusting the third lens unit L3 on the tool, it is possible to adjust the one-sided blur caused by errors due to decentering or tilting of a plurality of lenses constituting the third lens unit L3. On the other hand, when the optical adjustment is performed with the third to fifth lens groups L3 to L5 incorporated, in addition to the error in the third lens group L3, the relative decentration of the third to fifth lens groups L3 to L5. One-sided blur due to a manufacturing error due to tilting can be adjusted by the eccentricity of the leading lens of the third lens unit L3. With regard to the degradation component due to coma aberration after the decentering adjustment (optical adjustment) of the leading lens of the third lens unit L3, it is possible to obtain an optical system with improved performance by performing image processing by applying an image restoration filter. it can.

  FIG. 21 is an explanatory diagram of manufacturing error adjustment (optical adjustment) of the second optical system. Optical adjustment in an optical system having five groups of positive, negative, positive, negative, and positive in order from the object side to the image side. Shows how. In FIG. 21, a dotted line indicates a portion where one-sided blur and decentration coma are generated due to a manufacturing error. In the portion indicated by the dotted line, one-sided blur and peripheral coma aberration occur due to decentering or tilting when the lenses constituting the third lens unit L3 are assembled. By decentering (displacement) the leading lens indicated by the solid line in the third lens unit L3 in a direction substantially perpendicular to the optical axis OA, the reduction in the central MTF due to these single-blurring errors and decentration coma is reduced. Can be adjusted.

  FIG. 23 is an explanatory diagram of a method for generating an image restoration filter after optical adjustment for the second optical system, and shows a change in defocus characteristics of the MTF in the central portion and the peripheral portion due to the optical adjustment. FIG. 23A) shows the state of the design value at the telephoto end (Tele), where the MTF is sufficiently high at both the center and the periphery of the screen, and the field curvature at the center and the periphery is also in the + image height direction. There is no difference between the image height direction and the image height direction (small), and there is no one-sided blur. As described above, if there is a manufacturing error in the portion indicated by the dotted line or the alternate long and short dash line, as shown in FIG. 23B), a difference occurs in the image plane position in the + image height direction and the −image height direction. And the central MTF is lowered. By decentering one solid positive lens in a direction substantially perpendicular to the optical axis, the MTF reduction caused by the manufacturing error due to the center frame, etc., as shown in FIG. 23C), + image height direction and −image The center frame and one-sided blur can be adjusted by aligning the image plane positions in the high direction.

  However, at the wide-angle end (Wide), due to the difference in sensitivity to coma and chromatic coma due to manufacturing errors, from the design value shown in FIG. 23D), as shown in FIG. After the adjustment, one-sided blur due to chromatic coma or the like occurs. When optical adjustment is performed at the telephoto end, the one-blurring tendency is corrected even at the wide-angle end, but as shown in FIG. 23F), peripheral MTF reduction due to chromatic coma and coma remains.

  FIG. 23 shows a process of estimating the characteristics used for the image restoration filter from the series of optical adjustment steps shown in FIG. The MTF includes both a one-side blur change and a coma change due to optical adjustment. From the telephoto end characteristics shown in FIG. 23B), as shown in FIG. It is possible to estimate the blur component, and the one-side blur and coma aberration deterioration after optical adjustment. By creating an image restoration filter based on the characteristics shown in E) of FIG. 23 and applying it to the image after optical adjustment, it is possible to correct image degradation due to optical adjustment. In the optical adjustment method, the third lens group L3 is adjusted on the tool, and after the fourth and fifth lens groups L4 and L5 are assembled in the product state, the third lens group L3 is incorporated, and the third lens group L3 is assembled. Some adjustments may be made. In the former case, the error of the dotted line can be adjusted. In the latter case, it is possible to adjust both the dotted line and the dashed line error.

  The manufacturing error when mass-producing an optical system (lens) is different for each lens. For this reason, the one-side blur amount before optical adjustment differs depending on the error amount, and the displacement amount due to adjustment of the adjustment lens also differs. In the present embodiment, a plurality of types of predicted image restoration filters are prepared by predicting a deteriorated image at the wide-angle end or the intermediate region from the cause of deterioration estimated from the evaluation image at the telephoto end. A plurality of types of corresponding image restoration filters are prepared. As another method, optical adjustment data (displacement amount and displacement direction) is acquired from the adjustment displacement amount measuring means, and a plurality of image restoration filters that predict the cause of deterioration estimated from the information are prepared. In the present embodiment, an appropriate classification filter can be instantaneously selected from the image or the displacement amount in the adjustment state without analyzing the optically adjusted image in all zoom states. For this reason, it becomes possible to reduce the assembly man-hour required for optical adjustment.

  Next, with reference to FIG. 18 and FIG. 19, a method for manufacturing the imaging device according to the present embodiment (a method for determining an image restoration filter by performing optical adjustment of a lens) will be described. FIG. 18 is a configuration diagram of a manufacturing apparatus for the imaging apparatus 100 according to the present embodiment.

  As illustrated in FIG. 18, the manufacturing apparatus of the present embodiment includes an image evaluation unit 201, an optical adjustment unit 202, and an image restoration filter determination unit 203. The imaging optical system 101 includes a lens 101c to be optically adjusted. The image evaluation unit 201 evaluates an image (chart photographed image) obtained by photographing a predetermined subject such as a chart using the imaging optical system 101 before optical adjustment of the lens 101c. The optical adjustment unit 202 performs optical adjustment of the lens 101c with respect to a predetermined zoom range (first zoom range). Based on the data acquired from the image evaluation unit 201 and the optical adjustment unit 202, the image restoration filter determination unit 203 predicts an error state related to a zoom range (second zoom range) other than the zoom range where the optical adjustment has been performed. Determine an appropriate image restoration filter for that zoom range. The determined image restoration filter is stored in the storage unit 108 of the imaging apparatus 100 (image processing apparatus).

  In this embodiment, when the imaging optical system 101 is a lens device (an interchangeable lens) that can be attached to and detached from the imaging device main body having the imaging element 102, the image processing unit 104 and the storage unit 108 are provided inside the lens device. Also good.

  FIG. 19 is a flowchart illustrating a method for manufacturing the imaging device 100 according to the present embodiment. Each step in FIG. 19 is executed by each unit of the imaging apparatus manufacturing apparatus.

  First, in step S101, the image evaluation unit 201 acquires image evaluation data (evaluation value) regarding the first zoom range (for example, the telephoto end). Here, the image to be evaluated by the image evaluation unit 201 is a captured image acquired using the imaging optical system 101 before optical adjustment of the lens 101c. Preferably, the captured image is a chart captured image acquired in a state where the lens 101c is positioned in the first zoom range. At this time, the image evaluation unit 201 acquires evaluation data of the captured image related to the first zoom range based on the chart captured image acquired before the optical adjustment. Preferably, the evaluation data regarding the first zoom range is acquired by evaluating the shape of at least four PSFs around the screen. Preferably, the evaluation data relating to the first zoom range is acquired by evaluating at least four or more chromatic aberrations (color blur amounts) around the screen. Also preferably, the first zoom range includes the telephoto end of the imaging optical system 101 (lens 101c).

  Subsequently, in step S102, the optical adjustment unit 202 performs optical adjustment of the lens 101c in the first zoom range. The optical adjustment unit 202 acquires optical adjustment data (optical adjustment amount) of the lens 101c after optical adjustment. Preferably, the optical adjustment data includes a displacement amount of the lens 101c in the first zoom range. More preferably, the displacement amount of the lens 101c is a displacement amount along a direction (including a substantially perpendicular direction) perpendicular to the optical axis of the imaging optical system 101. Preferably, the optical adjustment data includes a displacement direction (for example, a direction perpendicular to the optical axis) of the lens 101c in the first zoom range. Preferably, the optical adjustment data includes a tilt amount of the lens 101c (also referred to as a tilt amount, an angle formed by the optical axis of the lens 101c and the optical axis of the imaging optical system 101) in the first zoom range. Preferably, the optical adjustment data includes a tilt direction of the lens 101c in the first zoom range.

  Subsequently, in step S103, the image restoration filter determination unit 203 determines an image restoration filter related to the second zoom range. Preferably, the image restoration filter is determined according to the residual aberration related to the second zoom range after the optical adjustment of the lens 101c, which is estimated based on the evaluation data and the optical adjustment data related to the first zoom range. Also preferably, the second zoom range includes the wide-angle end of the imaging optical system 101 (lens 101c).

  The image restoration filter determination unit 203 selects an appropriate image from a plurality of image restoration filters held in advance based on the evaluation data of the captured image regarding the first zoom range and the optical adjustment data of the lens 101c in the first zoom range. Select a recovery filter. The plurality of image restoration filters are classified in advance according to the optical adjustment data. Alternatively, the image restoration filter determination unit 203 may calculate an appropriate image restoration filter based on the evaluation data and the optical adjustment data.

  Subsequently, in step S104, the image restoration filter determination unit 203 stores the image restoration filter determined in step S103 in the storage unit 108 (memory) of the imaging apparatus 100. In this embodiment, the storage unit 108 is provided outside the image processing unit 104. However, the storage unit 108 is not limited to this, and is an internal memory of the image processing unit 104 (image processing apparatus) including a processor. Also good.

  As described above, in this embodiment, the image processing apparatus (imaging apparatus 100) includes a storage unit (a storage unit 108 such as a memory) and an image recovery unit (an image processing unit 104 such as a processor (an image recovery / distortion correction unit 104b). )). The storage unit stores an image restoration filter related to the second zoom range, which is determined based on the evaluation data of the captured image related to the first zoom range and the optical adjustment data of the lens in the first zoom range. The image restoration means performs a restoration process using an image restoration filter on an image shot in the second zoom range.

  Preferably, the image restoration unit performs a restoration process on an image shot in the first zoom range using an image restoration filter based on a design value of the imaging optical system 101 (lens 101c). Preferably, the image recovery means does not perform recovery processing on an image shot in the first zoom range. Preferably, the image restoration means performs a convolution process on the image using an image restoration filter having a filter value of a two-dimensional distribution based on the aberration information of the imaging optical system 101 (lens 101c). Perform recovery processing.

  According to the present embodiment, in the optical system including a manufacturing error, the second zoom range based on the evaluation data of the captured image acquired before the optical adjustment with respect to the first zoom range and the optical adjustment data in the first zoom range. An image restoration filter for can be determined. Thereby, the number of image evaluation processes is reduced (without acquiring evaluation data of a captured image related to the second zoom range), and an image processing device, a lens device, an imaging device, and An imaging device manufacturing method can be provided.

  Further, in order to reduce the size of the zoom lens or achieve a large aperture while maintaining the same size as the conventional one, it is necessary to increase the refractive power of each lens group constituting the zoom lens. At that time, the aberration sensitivity of each lens constituting the zoom lens increases, so that the optical adjustment is achieved by displacing the leading lens of the group that mainly forms one blur due to manufacturing errors in a direction substantially perpendicular to the optical axis. I do. Since image restoration is performed at a zoom position where optical adjustment is not performed, it is possible to ensure good optical performance over the entire area with a small lens having a strong refractive power in each group.

[Numerical Example 1]
Unit mm

Surface data surface number rd nd vd
1 105.495 0.50 1.91082 35.3
2 13.534 2.54
3 * -32.614 0.40 1.81000 41.0
4 * 382.536 0.29
5 15.186 1.68 2.00272 19.3
6 31.579 (variable)
7 * 7.246 2.09 1.58313 59.5
8 * -897.226 0.20
9 9.992 2.19 1.77250 49.6
10 -17.051 0.40 1.90366 31.3
11 7.319 0.89
12 -58.768 1.64 1.55332 71.7
13 * -11.359 (variable)
14 (Aperture) ∞ (Variable)
15 -20.186 1.47 2.00330 28.3
16 -9.642 0.75
17 * -6.874 0.30 1.81000 41.0
18 -24.709 (variable)
Image plane ∞

Aspheric data 3rd surface
K = 0.00000e + 000 A 4 = 1.60013e-004 A 6 = -4.54658e-007
4th page
K = 0.00000e + 000 A 4 = 2.22568e-004
7th page
K = 0.00000e + 000 A 4 = 1.61956e-005 A 6 = 2.10 100e-006
8th page
K = 5.16750e + 004 A 4 = 3.66194e-004 A 6 = -5.87897e-007
Side 13
K = 1.88643e + 000 A 4 = 4.34848e-004 A 6 = 3.12838e-005
17th page
K = 3.17908e-001 A 4 = 2.96339e-004 A 6 = 5.98863e-006
A 8 = 2.33686e-007

Various data Zoom ratio 2.85
Wide angle Medium Telephoto focal length 10.56 20.45 30.13
F number 2.88 4.22 5.55
Angle of view 32.47 21.36 14.87
Image height 6.72 8.00 8.00
Total lens length 42.93 37.35 39.50
BF 7.71 13.89 20.24

d 6 16.05 4.37 0.43
d13 0.50 0.50 0.50
d14 3.34 3.25 2.99
d18 7.71 13.89 20.24

Zoom lens group data group Start surface Focal length
1 1 -20.45
2 7 12.09
3 14 ∞
4 15 -38.46

[Numerical Example 2]
Unit mm

Surface data surface number rd nd vd
1 29.194 1.00 1.85478 24.8
2 22.456 4.62 1.69680 55.5
3 159.397 (variable)
4 47.728 0.80 1.88300 40.8
5 8.276 5.22
6 -26.153 0.80 1.60311 60.6
7 21.283 0.30
8 17.287 1.87 1.95906 17.5
9 65.570 (variable)
10 (Aperture) ∞ (Variable)
11 * 14.356 3.08 1.76802 49.2
12 * -34.617 0.80
13 -20.971 0.70 1.64769 33.8
14 -97.299 1.64 1.88300 40.8
15 -19.654 1.11
16 27.687 0.70 1.92286 18.9
17 8.581 4.21 1.49700 81.5
18 -15.335 (variable)
19 10.726 1.20 2.00272 19.3
20 18.520 0.39
21 174.532 0.60 1.77250 49.6
22 6.659 (variable)
23 * 19.229 1.77 1.85 135 40.1
24 -313.167 (variable)
25 ∞ 0.60 1.51633 64.1
26 ∞ (variable)
Image plane ∞

Aspheric data 11th surface
K = -4.84236e-001 A 4 = -4.94791e-005 A 6 = 3.16581e-008
12th page
K = 2.13838e + 000 A 4 = 1.06182e-004
23rd page
K = 0.00000e + 000 A 4 = 5.74439e-005 A 6 = 1.58141e-006

Various data Zoom ratio 3.43
Wide angle Medium telephoto focal length 6.15 16.85 21.08
F number 1.85 2.06 2.06
Angle of view 37.08 15.42 12.43
Image height 4.65 4.65 4.65
Total lens length 60.92 61.89 63.48
BF 3.96 3.96 3.96

d 3 0.35 12.07 14.35
d 9 16.98 4.93 2.05
d10 3.83 0.72 1.50
d18 0.50 3.49 4.10
d22 4.49 5.90 6.69
d24 1.82 1.82 1.82
d26 1.74 1.74 1.74

Zoom lens group data group Start surface Focal length
1 1 54.59
2 4 -9.91
3 10 ∞
4 11 11.60
5 19 -16.87
6 23 21.33
7 25 ∞

As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

104 Image processing unit (image processing apparatus)
104b Image recovery / distortion correction unit 108 Storage unit (storage unit)

Claims (17)

Storage means for storing an image restoration filter for the second zoom range determined based on the evaluation data of the captured image for the first zoom range and the optical adjustment data of the lens in the first zoom range;
An image processing apparatus comprising: an image recovery unit that performs a recovery process on the image captured in the second zoom range using the image recovery filter.   The image restoration filter is determined according to a residual aberration related to the second zoom range after optical adjustment of the lens, which is estimated based on the evaluation data and the optical adjustment data related to the first zoom range. The image processing apparatus according to claim 1.   The image processing apparatus according to claim 1, wherein the photographed image is a chart photographed image acquired in a state where the lens is positioned in the first zoom range.   4. The image processing apparatus according to claim 1, wherein the evaluation data related to the first zoom range is acquired by evaluating the shape of at least four PSFs around the screen. 5. .   The image processing apparatus according to claim 1, wherein the evaluation data related to the first zoom range is acquired by evaluating at least four or more chromatic aberrations around the screen.   The image processing apparatus according to claim 1, wherein the optical adjustment data includes a displacement amount of the lens in the first zoom range.   The image processing apparatus according to claim 1, wherein the optical adjustment data includes a displacement direction of the lens in the first zoom range.   The image processing apparatus according to claim 1, wherein the optical adjustment data includes an amount of inclination of the lens in the first zoom range.   The image processing apparatus according to claim 1, wherein the optical adjustment data includes an inclination direction of the lens in the first zoom range.   The image restoration means performs the restoration processing on an image photographed in the first zoom range by using an image restoration filter based on a design value of the lens. The image processing apparatus according to claim 1.   The image processing apparatus according to claim 1, wherein the image restoration unit does not perform the restoration process on an image shot in the first zoom range.   The image processing apparatus according to claim 1, wherein the first zoom range includes a telephoto end of the lens.   The image processing apparatus according to claim 1, wherein the second zoom area includes a wide-angle end of the lens.   The image restoration means performs the restoration process by performing a convolution process on the image using the image restoration filter having a two-dimensional distribution filter value based on the aberration information of the lens. The image processing apparatus according to claim 1, wherein the image processing apparatus is characterized in that: A lens that forms an optical image;
Storage means for storing an image restoration filter related to the second zoom range, which is determined based on evaluation data of the captured image related to the first zoom range and optical adjustment data of the lens in the first zoom range;
The lens apparatus further comprising: an image restoration unit that performs a restoration process using the image restoration filter on an image shot in the second zoom range. An image sensor that photoelectrically converts an optical image formed through a lens and outputs image data;
Storage means for storing an image restoration filter related to the second zoom range, which is determined based on evaluation data of the captured image related to the first zoom range and optical adjustment data of the lens in the first zoom range;
An image restoration device comprising: an image restoration unit that performs a restoration process using the image restoration filter on an image shot in the second zoom range. Obtaining evaluation data of a photographed image relating to the first zoom range;
Performing optical adjustment of the lens in the first zoom range;
And a step of determining an image restoration filter relating to a second zoom range based on the evaluation data and the optical adjustment data of the lens.