JP4565115B2 - Multifocal imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus, and more particularly to a multifocal imaging apparatus that can acquire images focused on a plurality of perspective positions on an imaging target by a single imaging operation.

  Currently, imaging devices are used in combination with image recognition devices, including manufacturing industries such as product inspection, quality control, manufacturing process management, image acquisition for information presentation, building It is used in various forms such as management.

  For example, in products used in the manufacturing process, products generally have a three-dimensional shape, but when performing inspection of minute parts, in order to perform more accurate inspection, an image pickup lens having a high NA is used. It has become like this. By using an imaging lens with a high NA, a large amount of light is captured, and the situation of fine parts becomes clearer. On the other hand, the depth of field is shallow, and the perspective position other than the focal point of the subject Then it will be blurred. Therefore, if you want to see not only a specific perspective position of the part but also the overall situation, it is necessary to refocus on another perspective position. It is difficult to do exactly.

  In order to obtain a stereoscopic image with a microscope, it is necessary to synthesize images at a plurality of focal positions. This means that images at different focal positions are acquired and synthesized in several times, and a single imaging operation is performed. Such an image cannot be acquired. There is also a technique that uses deconvolution by image processing. However, it is necessary to obtain a point response function, which results in a complicated image processing process and a long processing time. Therefore, a three-dimensional image can be easily obtained. It does n’t mean you can.

Multifocal image formation is disclosed in the following documents.
JP-A-6-70212 JP-A-4-329775 JP 11-311832 A Japanese Patent Laid-Open No. 10-254055 In Japanese Patent Laid-Open No. 10-260471, a change amount of image data is detected for each pixel or region of a plurality of original images having different focus positions in the same image frame, and this change amount is used as a reference. The present invention relates to an image processing apparatus that selects focused image data and generates a focused composite image as a whole screen using the image data. However, it does not specifically disclose how to acquire a plurality of images with different focus positions as an imaging device, and as a general imaging means, imaging is performed a plurality of times. This is an image processing method based on the above, and does not give a new feature as an imaging device for acquiring a plurality of multi-focus images.

  In Patent Document 2, light from the same subject is guided through an optical system, the light is divided into a plurality of light by a spectroscopic means, and photographing conditions such as an exposure amount and a focal position are made different from each other. The present invention relates to a solid-state imaging device that stores images simultaneously and stores images obtained by a solid-state imaging device arranged in each spectral path, and combines a plurality of images according to imaging conditions. However, among these imaging conditions, although the exposure amount is different for each spectral path and imaging can be performed simultaneously, the same optical system (objective lens) is used. Multiple images with different positions cannot be captured at the same time, and if a general imaging method is used, multiple images must be captured by adjusting the objective lens for each focal position, etc. There is nothing.

  Furthermore, as multifocal imaging devices for acquiring images focused on a plurality of perspective positions, there are those disclosed in Patent Documents 3 to 5, but in order to obtain images of different perspective positions, A plurality of objective lenses are provided, and imaging is performed by changing the focal position for each imaging lens. Any one of the plurality of objective lenses is selected, and imaging with a desired objective lens is performed. Therefore, the imaging apparatus is configured to include a plurality of objective lenses, and does not simultaneously capture images at different perspective positions.

  As described above, a conventional imaging apparatus or image forming apparatus that acquires images at different perspective positions uses a normal imaging apparatus, performs imaging multiple times at different perspective positions, and synthesizes images based on the imaging. One that performs image processing such as performing, or having a plurality of objective lenses for obtaining images at different perspective positions in one imaging device, and obtaining an image at a desired perspective position by selectively using the imaging lens There were things.

  In the case of image processing, in addition to taking time and manpower to obtain images at a plurality of perspective positions, such as performing image processing after performing multiple imaging, hardware for image processing and It is necessary to provide software means.

As in Patent Documents 3 to 5, a device having a plurality of objective lenses in one image pickup device is substantially similar to a combination of a plurality of image pickup devices, and the device becomes large-scale and perspective. In order to obtain a plurality of images having different positions, it was necessary to perform imaging a plurality of times.
As in Patent Document 2, even in the case of splitting light from one objective lens, if there is only one objective lens, it is necessary to perform imaging a plurality of times in order to select images at different perspective positions. It was.

  As described above, the conventional method and apparatus for obtaining a multifocal image cannot obtain images at different perspective positions by one imaging, and the scale of the imaging apparatus and the image processing apparatus is increased. Therefore, there has been a demand for providing an imaging apparatus that can obtain a plurality of images at different perspective positions by one imaging operation, and that can be reduced in cost with a simple configuration.

  The present inventor has filed as Japanese Patent Application No. 2006-121497 for an invention of a multifocal imaging device that has one objective lens and simultaneously captures a plurality of images at different perspective positions. In the present invention, the light transmitted through the objective lens is split by the beam splitter, and the optical path length changing means is provided in each of the split optical paths so that a plurality of images at different perspective positions can be captured simultaneously. There is a problem that the adjustment of the optical path length in the apparatus is not so easy.

The present invention has been made to solve the above-described problems, and a multifocal imaging device according to the present invention includes an objective lens; an angle inclined with respect to the direction of light passing through the objective lens and traveling through the first optical path. And a first splitter disposed with a first filter interposed in a plane perpendicular to the direction of the light reflected by the beam splitter and traveling on the second optical path. and mirror, and a second mirror disposed interposed the second filter between the plane perpendicular to the beam third direction of light traveling a light path through the spectral plane of the splitter Both the light reflected by the first mirror and transmitted through the spectral plane of the beam splitter and the light reflected by the second mirror and reflected by the spectral plane of the beam splitter are the same. A separation optical system configured to form an image on an image plane; And the first filter and the second filter transmit light of different color components, respectively, and at least one of the first mirror and the second mirror is in the direction of the optical path. The optical path length of the optical path from the objective lens through the first and second optical paths to the imaging plane and the first and third optical paths are used. By adjusting the optical path length of the optical path to the imaging plane to be different, an image focused on different positions of the imaging target can be captured by a single imaging operation.

  An objective lens; a first beam splitter having a first spectroscopic surface that forms an angle with respect to a direction of light traveling through the objective lens and on the first optical path; and a first beam splitter of the first beam splitter. A first mirror disposed with a first filter interposed in a plane perpendicular to the direction of light reflected on one spectral plane and traveling on a second optical path; and the first beam splitter A second beam splitter having a second spectral plane that is inclined with respect to the direction of light passing through the first spectral plane and traveling on the third optical path, and is reflected by the second beam splitter and is reflected by the fourth beam splitter. A second mirror disposed with a second filter interposed in a plane perpendicular to the direction of light traveling in the optical path, and the second spectral plane of the second beam splitter. A third filter is interposed in a plane perpendicular to the direction of light traveling along the fifth optical path. A third mirror disposed on the first beam splitter, reflected by the first mirror and transmitted through the first spectral plane of the first beam splitter, and reflected by the second mirror. Light reflected by the second spectral plane of the second beam splitter and further reflected by the first spectral plane of the first beam splitter and the second mirror of the second beam splitter reflected by the third mirror A separation optical system configured to form an image on the same imaging plane with light transmitted through the spectral plane and reflected by the first spectral plane of the first beam splitter. And the second filter and the third filter transmit light of different color components, respectively, and at least two of the first to third mirrors can move in the direction of the optical path Arranged in front of the objective lens The optical path length of the optical path reaching the imaging plane via the first optical path and the second optical path, and the imaging plane via the first optical path, the third optical path, and the fourth optical path By adjusting the optical path length of the optical path and the optical path lengths of the optical paths passing through the first optical path, the third optical path, and the fifth optical path to be different from each other, the plurality of positions of the imaging target are focused. The captured image may be captured by a single imaging operation.

  In addition, a beam splitter having a spectral plane that forms an angle with respect to the direction of light traveling through the first optical path, which is an incident optical path from the object to be imaged, and the light reflected by the beam splitter and traveling through the second optical path A first mirror disposed with a first filter interposed in a plane perpendicular to the direction, and a direction of light passing through the spectral plane of the beam splitter and traveling on the third optical path A second mirror disposed in a vertical plane with a second filter interposed therebetween, and the light reflected by the first mirror and transmitted through the spectral plane of the beam splitter; A separation optical system in which both the light reflected by the second mirror and the light reflected by the spectral plane of the beam splitter are combined; the light combined by the separation optical system is incident and the imaged object An objective lens for forming an image of the same image on the same image plane. The first filter and the second filter transmit light of different color components, and at least one of the first mirror and the second mirror moves in the direction of the optical path. An optical path length of an optical path from the imaged body through the first and second optical paths to the objective lens, and the first and third optical paths from the imaged body. By adjusting so that the optical path length of the optical path to the objective lens via the path differs, an image focused on a different position of the imaging target may be captured by a single imaging operation.

  In addition, a first beam splitter having a first spectral plane that forms an angle with respect to the direction of light traveling through the first optical path that is an incident optical path from the imaging target, and the first beam splitter of the first beam splitter. A first mirror disposed with a first filter interposed in a plane perpendicular to the direction of light reflected on one spectral plane and traveling on a second optical path; and the first beam splitter A second beam splitter having a second spectral plane that forms an angle with respect to the direction of light that passes through the first spectral plane and travels along the third optical path, and is reflected by the second beam splitter and reflected by the second beam splitter. A second mirror disposed with a second filter interposed in a plane perpendicular to the direction of light traveling in the optical path 4, and transmitted through the second spectral plane of the second beam splitter And a third filter is interposed in the plane perpendicular to the direction of the light traveling along the fifth optical path. A third mirror disposed, the light reflected by the first mirror and transmitted through the first spectral plane of the first beam splitter, and reflected by the second mirror and the first mirror. Light reflected by the second spectral plane of the second beam splitter and further reflected by the first spectral plane of the first beam splitter, and reflected by the third mirror and the second spectral of the second beam splitter. A separation optical system in which three lights, which are transmitted through the surface and reflected by the first spectral surface of the first beam splitter, are combined; and the light combined by the separation optical system is incident and An objective lens for forming an image of the imaged object on the same imaging plane, and the first filter, the second filter, and the third filter are different from each other. Of the first and third mirrors. At least two mirrors are arranged so as to be movable in the direction of the optical path, and the optical path length of the optical path from the imaging target to the objective lens via the first optical path and the second optical path, The optical path length of the optical path that reaches the objective lens via the first optical path, the third optical path, and the fourth optical path, and the optical path of the optical path that passes through the first optical path, the third optical path, and the fifth optical path By adjusting the length so as to be different from each other, an image focused on a plurality of positions of the imaging target may be captured by a single imaging operation.

  The image pickup device may further include an image pickup device disposed on the image formation surface, and an image signal obtained by the image pickup device may be taken out and processed by an external processing device. The image pickup device may be further provided with an image pickup control unit that performs processing for decomposing an image including a plurality of color component images obtained by the image pickup device into a plurality of color component images. Further, the image pickup control unit may perform image processing for combining an image separated into a plurality of color component images into one image.

  The multifocal imaging device of the present invention includes: an objective lens; a beam splitter having a spectral plane that forms an angle with respect to the direction of light that passes through the objective lens and travels along the first optical path; A first mirror disposed with a first polarizing plate interposed in a plane perpendicular to the direction of light reflected by the surface and traveling on the second optical path, and transmitted through the spectral plane of the beam splitter And a second mirror disposed with a second polarizing plate interposed in a plane perpendicular to the direction of the light traveling on the third optical path, the first mirror Both the light reflected and transmitted through the spectral plane of the beam splitter and the light reflected by the second mirror and reflected by the spectral plane of the beam splitter are imaged on the same imaging plane. A separation optical system; a first polarization direction and a second polarization with different polarization directions And light emitting means for sequentially illuminating the imaging target with predetermined light at a predetermined time, and the first polarizing plate in the separation optical system transmits light in the first polarization direction by the light emitting means. And the second polarizing plate transmits light in the second polarization direction, and at least one of the first mirror and the second mirror is arranged to be movable in the direction of the optical path. An optical path length from the objective lens to the imaging plane via the first and second optical paths and to the imaging plane via the first and third optical paths. After adjusting so that the optical path length of the optical path is different, the light with one polarization direction reaching the imaging plane via the first and second optical paths by the first light emission by the light emitting means. The first and third by imaging and second light emission by the light emitting means It is also possible to perform imaging with light of the other polarization direction that reaches the imaging plane via a path, and to capture images in focus at different positions on the imaging target by a series of imaging operations. Good.

  A beam splitter having a spectral plane that forms an angle with respect to the direction of the light traveling in the first optical path, which is an incident optical path of light from the imaging target, and the second beam reflected by the spectral plane of the beam splitter; A first mirror disposed with a first polarizing plate interposed in a plane perpendicular to the direction of light traveling in the optical path and the spectral plane of the beam splitter are transmitted through the third optical path. A second mirror disposed in a plane perpendicular to the direction of light with a second polarizing plate interposed therebetween, reflected by the first mirror, and spectrally separated by the beam splitter. A separation optical system in which both the light transmitted through the surface and the light reflected by the second mirror and reflected by the spectral surface of the beam splitter are combined; and the light combined by the separation optical system An objective lens for forming an image of the imaged object on the same image plane; Light emitting means for sequentially illuminating the imaging target with light of a first polarization direction and a second polarization direction that are different from each other at a predetermined time, and the first polarizing plate in the separation optical system Transmits the light in the first polarization direction by the light emitting means, and the second polarizing plate transmits the light in the second polarization direction. The first mirror, the second mirror, At least one of the mirrors is disposed so as to be movable in the direction of the optical path, and the optical path length of the optical path from the imaging target to the objective lens via the first and second optical paths, and the first and second After adjusting so that the optical path length of the optical path leading to the objective lens via the third optical path is different, the first and second optical paths due to the first light emission by the light emitting means are Imaging with light in one polarization direction to the image plane , Imaging with light of the other polarization direction that reaches the imaging plane via the first and third optical paths by the second light emission by the light emitting means, and focuses at different positions on the imaging target You may enable it to image a suitable image by a series of imaging operations.

An objective lens; a polarization beam splitter having a polarization separation surface that forms an angle with respect to the direction of light passing through the objective lens and the first optical path; and reflected by the polarization separation surface of the polarization beam splitter And a first mirror disposed in a plane perpendicular to the direction of light traveling in the second optical path, and the direction of light traveling through the polarization separation plane of the polarization beam splitter and traveling through the third optical path. And a second mirror disposed in a vertical plane, the light reflected by the first mirror and transmitted through the polarization separation surface of the polarization beam splitter, and reflected by the second mirror A separation optical system in which both the light reflected by the polarization separation surface of the polarization beam splitter forms an image on the same image formation surface; a first polarization direction and a second polarization direction different from each other ; Hold the object to be imaged for a predetermined time with the polarized light. Light emitting means for successively illuminating; it includes a said separating optical system polarization separation surface while the other both perpendicular thereto to transmit light in the polarization direction of the polarization of the polarization direction orthogonal in polarizing beam splitter Direction light is reflected , and at least one of the first mirror and the second mirror is arranged so as to be movable in the direction of the optical path, and the first and first mirrors from the objective lens. After adjusting so that the optical path length of the optical path reaching the imaging plane via two optical paths and the optical path length of the optical path reaching the imaging plane via the first and third optical paths are different, Imaging with light of one polarization direction reaching the imaging plane via the first and second optical paths by the first light emission by the light emitting means, and the second light emission by the light emitting means. The imaging through the first and third optical paths Perform the imaging in the other polarization direction of light reaching the, it may be an image-focus in different positions in the imaged subject can be imaged by a series of imaging operations.

In addition, a polarization beam splitter having a polarization separation surface that forms an angle with respect to the direction of light traveling along the first optical path that is an incident light path from the imaging target, and the light reflected by the polarization separation surface of the polarization beam splitter. A first mirror disposed in a plane perpendicular to the direction of the light traveling on the second optical path, and the direction of the light transmitted through the polarization separation surface of the polarization beam splitter and traveling on the third optical path A second mirror disposed in a vertical plane, and the light reflected by the first mirror and transmitted through the polarization separation surface of the polarization beam splitter and reflected by the second mirror. A separation optical system in which both the light reflected by the polarization separation surface of the polarization beam splitter and the light combined by the separation optical system are incident, and the image of the object to be imaged is the same An objective lens for forming an image on the imaging plane; Light emitting means for illuminating the object to be imaged sequentially at a predetermined time respective in light of different first polarization direction and the second polarization direction Re; be provided with, in the polarization beam splitter of said separating optical system The polarization separation surface transmits light in one of the orthogonal polarization directions and reflects light in the other polarization direction perpendicular thereto , and the first mirror, the second mirror, At least one of the mirrors is disposed so as to be movable in the direction of the optical path, and the optical path length of the optical path from the imaging target to the objective lens via the first and second optical paths, and the first and second After adjusting so that the optical path length of the optical path leading to the objective lens via the third optical path is different, the first and second optical paths due to the first light emission by the light emitting means are With light in one polarization direction that reaches the image plane Different positions on the imaged object are obtained by imaging and imaging with light of the other polarization direction that reaches the imaging plane via the first and third optical paths by the second light emission by the light emitting means. An image that is focused on may be captured by a series of imaging operations.

  The image pickup device may further include an image pickup device disposed on the image formation surface, and an image signal obtained by the image pickup device may be taken out and processed by an external processing device. An image pickup device provided, a memory for storing and holding an image obtained by the image pickup device, and an image pickup control unit; and focusing on different positions in the object to be picked up obtained by the image pickup device by a series of image pickup operations. A plurality of images that match each other may be stored and held separately, and the imaging control unit may perform image processing for combining the plurality of images stored and held separately as one image. Good.

  A motor serving as a drive source for moving one of the first mirror and the second mirror in the direction of the optical path, and the optical path by the movement of the mirror from the rotation angle of the motor in the imaging control unit; The amount of change in the length is obtained, and from the amount of change in the optical path length, a calculation is performed to obtain the height as a difference in position on the imaged object before and after the change of the optical path length. You may enable it to measure the height in a to-be-photographed object while performing the imaging of the focused image by one time or a series of imaging operation.

  In the multifocal imaging device of the present invention, the optical path lengths are made different in a plurality of optical paths dispersed by the beam splitter, and then imaged on one imaging element, so that a plurality of different ones are obtained by one imaging operation. One image focused on the position can be obtained, and the one image can be decomposed into a plurality of images, and can be combined as one image by performing image processing and image composition processing. By using a Michelson interferometer type separation optical system, the optical path length can be easily adjusted. In addition, the height of the imaging target can be measured together with the imaging of the imaging target from the amount of change in the optical path length.

  In the multifocal imaging device according to the present invention, light is split into a plurality of optical paths in the imaging optical system, and the optical path lengths of the split optical paths are made different from each other, and then combined into one optical path and guided to the imaging device. There are cases where a separation optical system is provided and an objective lens is provided on the front side of the separation optical system, and an objective lens is provided between the separation optical system and the image sensor. A Michelson interferometer type is used as the separation optical system.

  FIG. 1 shows an example of a form having an objective lens on the front side of a separation optical system. The imaging unit of the multifocal imaging device A makes an angle of, for example, 45 ° with respect to the direction of light passing through the objective lens 1. None A beam splitter 2 having a spectral plane that reflects some light and transmits other light, and a filter 4a interposed in a plane perpendicular to the direction of the light reflected by the spectral plane of the beam splitter 2 The mirror 3a disposed in a plane, the mirror 3b disposed in the plane perpendicular to the direction of the light transmitted through the spectral surface of the beam splitter 2 with a filter 4b interposed therebetween, and reflected by the mirror 3a. The imaging device 7 is disposed on the imaging plane of both the light transmitted through the spectral surface of the beam splitter and the light reflected by the mirror 3 b and reflected by the spectral surface of the beam splitter 2.

  Reference numeral 14 denotes an image pickup control unit, 15 denotes a memory for holding image data generated by the image pickup device 7, and 16 denotes a monitor unit for displaying an image. The imaging control unit 14 controls the imaging operation, and controls the image to be decomposed into a plurality of images by color components, and each image data is held in the memory 15 and displayed on the monitor 16. Although an example in which an angle of 45 ° is formed with respect to the light incident on the spectral plane of the beam splitter 2 is shown, other inclination angles may be appropriately set without being particularly 45 °. In addition, in the optical system of the image pickup unit, a fixed distance from the objective lens 1 to the image sensor 7 is basically considered, and a microscope-type image forming optical system that performs focus position adjustment by changing the distance between the image pickup unit and the imaging target. It is a system. As means for illuminating the object to be imaged with such an optical system, epi-illumination means (not shown) for providing illumination light in the direction of the optical axis of incident light to the object to be imaged may be provided at the front part of the imaging unit. Good.

  The mirror 3a is a fixed mirror, and the mirror 3b is attached to a stage that can move in the direction of light, and the position of the mirror 3b can be adjusted in the direction of light by means of a screw 6, which serves as an optical path length changing means. The optical path length of the optical path from the objective lens to the image sensor 7 can be adjusted by moving the mirror 3b in the light direction. For example, the filter 4a is a filter that transmits R component light, and the filter 4b is a filter that transmits G component light.

In the imaging unit having such an optical system, light from the position P ₀ of the imaging target B passes through the objective lens, and the R component light reflected by the spectral surface of the beam splitter 2 and reflected by the mirror 3a is reflected by the beam splitter. The position of the imaging unit and the imaging target is adjusted so as to form an image on the imaging device 7 between the imaging unit and the imaging target through the two spectral planes, and the position of the mirror 3b is adjusted by the screw 6. Thus, light from the position P ₀ of the imaging target B is imaged on the imaging element 7. This image formation state can be confirmed while viewing the color component separation image of the R component and G component light on the monitor 16.

In this state, the optical path length of the light that reaches the image sensor 7 after being reflected by the mirror 3b is the same as the optical path length of the light that is reflected by the mirror 3a and reaches the image sensor 7. When this relative position the position of the mirror 3b the position of P ₀ is formed on the image sensor 7 of the imaged subject B, the mirror 3b moves in the direction away from the beam splitter 2 by screws 6, the position P of the object to be imaged The light from ₁ forms an image on the image sensor 7. When the mirror 6 is moved in the direction approaching the beam splitter 2 by the screw 6, the light from the position P _{2 of the} imaging target is imaged on the imaging element 7.

Thus after having moved modulating mirror 3b from the reference position, when the imaging operation by the imaging control unit 14, and the image of the R component light focused on the position of P ₀ of the imaged subject B, P ₁ or an image of the G component light focused in a different perspective position as P ₂ is imaged simultaneously. The two color component images are decomposed by the color component in the imaging control unit 14 so that the R component image focused on the position P ₀ and the G component image focused on the position P ₁ or P _2. Are decomposed into two images. Furthermore, if necessary, the image of each of the R and G component lights may be converted into a black and white image. In addition, although the mirror 3b is shown as being movable adjustable as the optical path length changing means, both the mirror 3a and the mirror 3b may be adjustable.

  FIG. 2 shows an image pickup apparatus having a separation optical system in which a beam splitter is added so that an image focused at three positions can be obtained. The image pickup apparatus includes an objective lens on the front side of the separation optical system. ing. The imaging unit of the multifocal imaging device A in FIG. 2 has a beam splitter having a spectral plane that forms an angle of, for example, 45 ° with respect to the direction of light passing through the objective lens 1 and reflects some light and transmits other light. 2a, a mirror 3a disposed in a plane perpendicular to the direction of light reflected by the spectral plane of the beam splitter 2a, with a filter 4a interposed therebetween, and light transmitted through the spectral plane of the beam splitter 2a. For example, a beam splitter 2b having a spectral plane that forms an angle of 45 ° with respect to the direction and reflects some light and transmits other light, and is perpendicular to the direction of the light reflected by the spectral plane of the beam splitter 2b A mirror 3b disposed in the plane with a filter 4b interposed therebetween, and a plane perpendicular to the direction of light transmitted through the spectral surface of the beam splitter 2b with a filter 4c interposed therebetween. With mirror 3c and mirror 3a The light reflected and transmitted through the spectral plane of the beam splitter 2a, the light reflected by the mirror 3b and reflected by the spectral plane of the beam splitter 2b and the spectral plane of the beam splitter 2a, and the spectral plane of the beam splitter 2b reflected by the mirror 3c. And an image pickup device 7 disposed at a position where an image of light transmitted through and reflected by the spectral surface of the beam splitter 2a is imaged. Although an example in which the spectral planes of the beam splitters 2a and 2b are each at an angle of 45 ° with respect to the incident light has been shown, other angles may be appropriately formed.

  Reference numeral 14 denotes an imaging control unit including a memory that controls the imaging operation and separates the image into a plurality of images by color components and holds data of each image, and 16 is a monitor unit that displays the image.

  At least two of the mirrors 3a to 3c are attached to a stage that can move in the direction of light (in FIG. 2, the mirrors 3b and 3c are movable), and the mirrors 3b and 3c are respectively lighted by screws 6b and 6c. The position can be adjusted in the direction of. By moving the mirror 3b and the mirror 3c in the direction of light, the optical path length of the optical path reflected from the objective lens by the respective movable mirrors and reaching the image sensor 7 can be adjusted. For example, the filter 4a is a filter that transmits R component light, the filter 4b is a filter that transmits G component light, and the filter 4c is a filter that transmits B component light.

In the imaging unit having such an optical system, the light from the position P ₀ of the imaging target B passes through the objective lens, the R component light reflected by the spectral surface of the beam splitter 2a and reflected by the mirror 3a is captured by the imaging device. 7, the position of the imaging unit and the object to be imaged is adjusted, and then the position of the mirror 3 b is adjusted by the screw 6 b, and the mirror 3 b out of the light from the position P ₀ of the object B to be imaged. The reflected G component light forms an image on the image sensor 7, and the position of the mirror 3 c is adjusted by the screw 6 c, so that the B component light out of the light from the position P ₀ of the imaging target B is applied to the image sensor 7. Let them image. Confirmation of these imaging states can be performed by viewing the decomposed images of the R component, G component, and B component light on the monitor unit 16. Thus, the optical path lengths of the light beams that are reflected by the mirror 3a, the mirror 3b, and the mirror 3c and reach the image sensor 7 are the same with the positions of the mirrors 3b and 3c adjusted.

Mirror 3b the position of P ₀ of the object to be imaged B is formed on the imaging device 7, as a reference position a position of the mirror 3c, by the mirror 3b moves adjusted by screws 6b, for example, the position P ₁ of the object to be imaged The light from the light is imaged on the image sensor 7. Similarly, by the mirror 3c moves adjusted by screws 6c, the light from the position P ₂ of the object to be imaged is cause to image on the imaging element 7.

Thus mirror 3b, by moving adjusting the mirror 3c from the reference position, the image of the R component light-focus to the position of P ₀ of the imaged subject B, G component-focus to the position of P ₁ One image is obtained in which the light image and the B component light image focused on the position of P ₂ are simultaneously formed. If degradation by each color component of the three color component images by the function of the imaging control unit 14, P R component light image-focus at the position of _0, the image of the G component light focused on the position of P ₁ decomposition of the image of the B component light focused on the position of P ₂ is made. Furthermore, the R, G, and B component light images may be converted into black and white images as necessary. Furthermore, it is possible to perform image processing on each decomposed image and combine them as one image.

  3A and 3B show the configuration of the optical system of the imaging unit. In the image pickup unit of the image pickup apparatus shown in FIG. 1, the light from the objective lens 1 is divided into two by the beam splitter 2a, reflected by the mirror 3a and the mirror 3b, and then transmitted or reflected by the spectral plane of the beam splitter 2a and united. When the portion including the beam splitter 2a, the mirror 3a, and the mirror 3b is viewed as the separation optical system SP, it is as shown in FIG. In this case, the optical path length in the image space is adjusted by the optical path length changing means in the optical path of the separation optical system. In FIG. 3B, the light is separated and united by the separation optical system SP, and then passes through the objective lens and reaches the image sensor. In this case, the optical path length in the object space is adjusted by the optical path length changing means in the optical path of the separation optical system.

  As a configuration of the imaging device, as shown in FIGS. 3A and 3B, the objective lens 1, the separation optical system SP, the imaging device, and the control unit are formed as an integrated device. As shown in (c), the objective lens 1 and the separation optical system SP may be formed as a unit and attached to the body of a single-lens reflex imaging camera including an imaging device and a control unit. In addition, an attachment type configuration that is mounted on a screw mount of an imaging camera including an objective lens as a unit having only the elements of the separation optical system SP may be employed. In addition, the image pickup apparatus performs image processing such as color separation and black-and-white conversion on an image obtained by combining the image components after separation into color components in the separation optical system as shown in FIGS. Although it is necessary, the imaging control unit 14 may include a processing circuit for performing a processing device therefor, or may be performed as a function of a general-purpose personal computer.

  The image pickup apparatus is described as having a configuration in which an image pickup element is disposed on an image formation surface of light from an object to be picked in an optical system of an image pickup unit including an objective lens and a separation optical system. Here, the image sensor converts the formed image into image data, performs focus position adjustment, adjustment of the optical path length, etc. while looking at the monitor screen, and further stores the image data in a memory. However, it is only necessary to be able to confirm the image that is being imaged for operations such as focusing and adjusting the optical path length.For example, a display surface such as a matte surface is provided at a position conjugate to the imaging surface. It is also made with an optical viewfinder. Therefore, in the present invention, disposing an image sensor on the image plane is considered as an embodiment and is not indispensable.

  FIG. 4 shows a configuration in which a polarizing plate is used instead of a filter in the configuration of the optical system as shown in FIG. 1 differs from FIG. 1 in that a polarizing plate 5a is provided in place of the filter 4a, a polarizing plate 5b is provided in place of the filter 4b, and the illumination device 10 is provided with light having a different polarization direction. The imaging control unit 14 controls the imaging operation in synchronization with the light emission of the light emitting means of the illumination device 10, and is otherwise the same as in the case of FIG. The polarizing plate 5a and the polarizing plate 5b are in a relationship in which the polarization directions of light to be transmitted are orthogonal to each other, and the illumination device 10 has two equivalent light emitting elements 11a and 11b and a light emission driving unit 12, and the light emitting element 11a has a polarization. A plate 13a is attached to the light emitting element 11b, and a polarizing plate 13b is attached to the light emitting element 11b. The polarizing plates 13a and 13b are in a relationship in which the directions of polarization of light to be transmitted are orthogonal to each other. Give illumination light in different directions. The light emission driving unit 13 drives and controls the imaging operation of the imaging apparatus so that the light emitting elements 11a and 11b emit pulsed light with a time difference according to a signal from the imaging control unit 14. This time difference is assumed to be larger than at least the time interval required for the preceding and following imaging operations in the imaging device 7.

When an image focused at a different position is picked up by the image pickup apparatus having the configuration shown in FIG. 4, as in the case of FIG. 1, the focus is set at the position P ₀ of the object to be picked up by the optical path reflected by the mirror 3a. The position interval between the imaging unit and the imaging target is adjusted so that they match, and the mirror 3 b is adjusted by the screw 6 so that the same position P ₀ of the imaging target B is in focus. When adjusting the focus and adjusting the mirror 3b, the illumination device 10 is used to illuminate the object to be imaged and the display image on the monitor 16 is viewed. As the position reference position of the thus adjusted mirror 3b, by operating the screw 6, so that in focus on the position of P ₁ or P ₂ of the imaged subject by light towards the reflecting mirror 3b. After that, when the light emitting element 11a emits light according to the signal from the imaging control unit 14, an image is formed on the imaging element 7 in the optical path passing through the polarizing plate that transmits this light, with a time difference. When the light emitting element 11b emits light, an image is formed on the imaging element 7 in an optical path that passes through the polarizing plate that transmits this light. The imaging control unit 14 performs control so that both images are sequentially held in the memory 15.

  In the multifocal imaging device of FIG. 4, data of images focused on different positions of the imaging target obtained by sequentially illuminating the imaging target with light having different polarization directions are sequentially stored and held in the memory 15. . Images focused on the different positions can be taken out separately, and further image processing can be performed to combine them as one image. As the imaging device, the imaging control unit may have an image processing circuit for synthesizing a plurality of images for that purpose, or image data can be transmitted and image processing is performed by a general-purpose personal computer as an external device. Also good.

  The optical system of the image pickup apparatus of FIG. 4 is in the form of FIG. 3A, and the objective lens 1 is disposed on the front side of the separation optical system SP. However, as shown in FIG. The objective lens 1 can also be arranged between the two. In the configuration using a polarizing plate as shown in FIG. 4, a filter that separates the color components is not used, and therefore an image focused on different positions of the imaging target using a monochrome type (black and white type) imaging device. Can be imaged. In addition, after adjusting the optical path length so that different positions on the imaging target are in focus, imaging is performed as a series of operations by the first light emission by the light emitting means and the second light emission after a predetermined time. The

  In FIG. 4, a polarizing plate 5a and a polarizing plate 5b in which the polarization directions of light transmitted through the light path through which the light from the objective lens 1 is reflected and transmitted through the beam splitter 2a are orthogonal to each other are disposed. However, the beam splitter 2a may be a polarizing beam splitter that transmits light in one polarization direction and reflects light in the other polarization direction whose polarization direction is perpendicular thereto. In this case, no polarizing plate is provided in the bisected optical path in FIGS.

  FIG. 5 shows an example in which the imaging apparatus having the optical system of FIG. 1 is provided with a function of measuring the height of an object to be imaged. The configuration of FIG. 5 differs from that of FIG. 1 in that a pulse motor 9 for moving the mirror 3b is provided instead of using the screw 6 for moving the mirror 3b to adjust the optical path length. 9 is transferred to the imaging control unit 14, and based on the signal from the encoder 9a, the imaging control unit 14 calculates the change amount of the optical path length from the rotation amount of the pulse motor 9 to the moving distance of the base 8b. That is to calculate and obtain.

とし、光路長の変化量を±ｃ（ｃ＞０）とした時にａが（ａ＋Δａ）になったとすると、

の関係式になる（＋ｃは光路長が長くなる場合、−ｃは光路長が短くなる場合）。ｆ、ｂは撮像装置において既定の値であるので、式（１）、（２）から光路長の変化ｃに対する被撮像体における位置の差Δａが求められる。Δａが＋の値であれば図でＰ_１はＰ_０より上側、Δａが−の値であればＰ_１はＰ_０より下側の位置である。ｂの値は最初に被撮像体に基準の位置に焦点を合わせる時の光路長を基準としてｂの値とし、図１の場合のようにミラー３ａを固定とした場合、固定されたミラー３ａで反射する方の光路ではｂの値は対物レンズから撮像素子に至る光路長であるが、ミラー３ａ、３ｂをともに移動可能にして両方の光路の光路長を可変とした場合には、パルスモータの回転角により対物レンズから撮像素子までの距離が割り出せる形にしておき、最初に被撮像体の基準位置に焦点を合わせた時の対物レンズから撮像素子までの距離をｂの値とする。制御部１４では式（１）、（２）とパルスモータの回転角から得られたｃの値とからΔａの値を求める計算をし、結果をモニター１５に表示する。一方で、撮像装置としては、一方の光路が被撮像体のＰ_０の位置に、他方の光路がＰ１の位置に焦点が合う状態になっており、１回の撮像操作でそれぞれ異なる位置に焦点の合った画像が撮像される。このように、図５に示す構成とすることにより、被撮像体の異なる遠近位置に焦点が合った画像が得られるとともに、その位置間の距離としての高さが求められる。 When the imaging apparatus having the configuration shown in FIG. 5 captures an image focused on different perspective positions of the imaging target B and measures the height thereof, each of the images is first separated on the spectral plane of the beam splitter 2 in FIG. The positional relationship between the imaging device and the imaging object is set so that the image on the optical path of the imaging object is in focus on the position of P ₀ of the imaging object B, and the position of P ₀ is used as a height reference. To do. Thereafter, by moving the mirror 3b by rotating the pulse motor 9 to change the optical path length of the optical path of the right image in the optical path towards the reflection it is assumed that there is a focus on the position of P ₁ by the mirror 3b Like that. The operation of focusing on the positions of the reference positions P ₀ and P ₁ is performed while checking images on the respective optical paths on the monitor 16. The imaging control unit obtains the rotation angle of the pulse motor 9 at this time based on a signal from the encoder 9a attached to the pulse motor 9, and determines the optical path length due to the movement of the mirror 3b from the rotation angle of the pulse motor 9. The amount of change is obtained, and the distance from P ₀ to P ₁ in the image pickup object B is calculated as the height from the amount of change in the optical path length. The calculation of the height includes the focal length f of the objective lens 1, the distance a from the point on the image pickup object B to the objective lens 1, and the distance b from the objective lens 1 to the imaging plane (the surface of the imaging device 7). The relation between

Suppose that a becomes (a + Δa) when the change amount of the optical path length is ± c (c> 0).

(+ C is when the optical path length is long, -c is when the optical path length is short). Since f and b are predetermined values in the imaging apparatus, a difference Δa in position on the imaging object with respect to the change c of the optical path length is obtained from the equations (1) and (2). P ₁ in FIG. If the value of .DELTA.a is + is above the P _0, .DELTA.a is -, P ₁ If the value of the position of the lower side of the P _0. The value of b is the value of b based on the optical path length when the object is first focused on the reference position, and when the mirror 3a is fixed as in FIG. 1, the fixed mirror 3a is used. In the reflecting optical path, the value b is the optical path length from the objective lens to the image sensor. However, when both the optical paths of the mirrors 3a and 3b are movable and the optical path lengths of both optical paths are variable, The distance from the objective lens to the image sensor is determined by the rotation angle, and the distance from the objective lens to the image sensor when the focus is first set on the reference position of the object to be imaged is a value b. The control unit 14 calculates the value of Δa from the expressions (1) and (2) and the value of c obtained from the rotation angle of the pulse motor, and displays the result on the monitor 15. On the other hand, as an imaging device, one optical path is in focus at the position P ₀ of the imaging target, and the other optical path is in focus at the position P 1. A suitable image is captured. As described above, with the configuration shown in FIG. 5, an image focused on different perspective positions of the imaging target is obtained, and the height as the distance between the positions is obtained.

の形になり、光路長がｃだけ変化したとすれば、この変化分は被撮像体における高さΔａになっている。パルスモータの回転角に応じて求められた光路長の変化量±ｃに対して、制御部において式（１）、（３）を用いて被撮像体における位置の差としての高さΔａを求める演算がなされ、モニターでの表示がなされる。 Expression (2) is a case of the imaging optical system in the form of FIG. 3A, and measures the height of the imaging target by adjusting the optical path length in the image space. Similarly, in the case of the imaging optical system of the shape, it is possible to measure the height of the object to be imaged. In this case, the only difference from the imaging optical system in FIG. 4 is that the objective lens is disposed on the rear side of the separation optical system, and the separation optical system adjusts the optical path length in the object space. . At that time, the expression representing the imaging relationship is

If the optical path length changes by c, the amount of change is the height Δa in the imaged body. With respect to the optical path length variation ± c obtained according to the rotation angle of the pulse motor, the control unit obtains the height Δa as the difference in position on the image pickup body using the equations (1) and (3). Calculations are made and displayed on the monitor.

It is a figure which shows one form of the multifocal imaging device by this invention. It is a figure which shows the other form of the multifocal imaging device by this invention. It is a figure which mainly shows the form of the optical system of an imaging part. It is a figure which shows the further another form of the multifocal imaging device by this invention. It is a figure which shows the example of the imaging device provided with the function to measure the height in a to-be-photographed body.

Explanation of symbols

A Imaging device B Object 1 Objective lens
2, 2a, 2b Beam splitter 3a, 3b, 3c Mirror 4a, 4b, 4c Filter 5a, 5b Polarizing plate 6, 6b, 6c Screw 7 Imaging element 9 Pulse motor 10 Illumination device 11a, 11b Light emitting element 12 Light emitting drive part 13a, 13b Polarizing plate 14 Imaging control unit 15 Memory 16 Monitor

Claims (15)

An objective lens;
A beam splitter having a spectral plane inclined at an angle with respect to the direction of light passing through the objective lens and traveling on the first optical path, and perpendicular to the direction of light reflected by the beam splitter and traveling on the second optical path a first mirror disposed by interposing a first filter between the plane, in a plane perpendicular to the direction of the transmitted through the spectral plane of the beam splitter third light traveling the optical path A second mirror disposed with a second filter interposed therebetween, and the light reflected by the first mirror and transmitted through the spectral plane of the beam splitter and the second mirror A separation optical system in which both the light reflected and reflected by the spectral plane of the beam splitter are imaged on the same imaging plane;
The first filter and the second filter transmit light of different color components, respectively, and at least one of the first mirror and the second mirror is Arranged so as to be movable in the direction of the optical path, the optical path length of the optical path from the objective lens through the first and second optical paths to the imaging plane and the first and third optical paths The optical path length to the imaging plane is adjusted to be different so that images focused on different positions of the imaging target can be captured by one imaging operation. Focus imaging device.
An objective lens;
A first beam splitter having a first spectroscopic surface that forms an angle with respect to the direction of light traveling through the objective lens and the first optical path, and reflected by the first spectroscopic surface of the first beam splitter; A first mirror disposed with a first filter interposed in a plane perpendicular to the direction of light traveling in the second optical path, and a first spectral plane of the first beam splitter. And a second beam splitter having a second spectral plane that forms an angle with respect to the direction of light traveling through the third optical path and reflected by the second beam splitter and traveling along the fourth optical path. A second mirror disposed with a second filter interposed in a plane perpendicular to the direction, and the second light splitting surface of the second beam splitter, passing through a fifth optical path. A third filter disposed in a plane perpendicular to the direction of light with a third filter interposed therebetween; Light reflected by the first mirror and transmitted through the first spectral plane of the first beam splitter, and reflected by the second mirror and second of the second beam splitter. And reflected by the first spectral plane of the first beam splitter and reflected by the third mirror and transmitted through the second spectral plane of the second beam splitter. A separation optical system configured such that the light reflected by the first spectral plane of the beam splitter forms an image on the same imaging plane;
And the first filter, the second filter, and the third filter transmit light of different color components, respectively, and at least one of the first to third mirrors Two mirrors are disposed so as to be movable in the direction of the optical path, the optical path length of the optical path from the objective lens to the imaging plane via the first optical path and the second optical path, and the first , The third optical path, the fourth optical path, the optical path length of the optical path reaching the imaging plane, and the optical path length of the optical path passing through the first optical path, the third optical path, and the fifth optical path. And a multi-focal imaging device that can adjust an image focused on a plurality of positions of the imaging target by a single imaging operation. A beam splitter having a spectral plane that forms an angle with respect to the direction of light traveling through the first optical path that is the incident optical path from the imaging target, and in the direction of light reflected by the beam splitter and traveling through the second optical path A first mirror disposed in a plane perpendicular to the first mirror, and a direction perpendicular to the direction of light passing through the spectral plane of the beam splitter and traveling on the third optical path. A second mirror disposed in the plane with a second filter interposed therebetween, the light reflected by the first mirror and transmitted through the spectral plane of the beam splitter, and the second mirror A separation optical system in which both the light reflected by the mirror and the light reflected by the spectral plane of the beam splitter are combined,
An objective lens for forming the image of the imaged body on the same image plane when the light combined by the separation optical system is incident;
The first filter and the second filter transmit light of different color components, and at least one of the first mirror and the second mirror has an optical path And an optical path length of an optical path from the image pickup body through the first and second optical paths to the objective lens, and from the image pickup body to the first and the first optical paths. By adjusting so that the optical path length of the optical path leading to the objective lens via the optical path 3 is different, an image focused on different positions of the imaging target can be captured by a single imaging operation. A multifocal imaging device. A first beam splitter having a first spectroscopic surface that forms an angle with respect to the direction of light traveling along a first optical path as an incident optical path from the imaging target; and a first beam splitter of the first beam splitter A first mirror disposed with a first filter interposed in a plane perpendicular to the direction of light reflected on the spectroscopic surface and traveling on the second optical path; and a first mirror of the first beam splitter. A second beam splitter having a second spectral plane that forms an angle with respect to the direction of light passing through the first spectral plane and traveling through the third optical path, and is reflected by the second beam splitter and is reflected by the fourth beam splitter. A second mirror disposed with a second filter interposed in a plane perpendicular to the direction of light traveling in the optical path and the second spectral plane of the second beam splitter are transmitted through the second mirror. 5 with a third filter interposed in a plane perpendicular to the direction of light traveling along the optical path 5 A third mirror that is reflected by the first mirror and transmitted through the first spectral plane of the first beam splitter and reflected by the second mirror and the second mirror. The light reflected by the second spectral plane of the beam splitter, reflected by the first spectral plane of the first beam splitter, and reflected by the third mirror and reflected by the second spectral plane of the second beam splitter. A separation optical system in which three lights, which are transmitted and reflected by the first spectral surface of the first beam splitter, are combined,
An objective lens for forming the image of the imaged body on the same image plane when the light combined by the separation optical system is incident;
And the first filter, the second filter, and the third filter transmit light of different color components, respectively, and at least one of the first to third mirrors Two mirrors are disposed so as to be movable in the direction of the optical path, and the optical path length of the optical path from the imaging target to the objective lens via the first optical path and the second optical path, and the first The optical path length of the optical path passing through the first optical path, the third optical path, and the fourth optical path to the objective lens, and the optical path length of the optical path passing through the first optical path, the third optical path, and the fifth optical path, A multi-focus imaging apparatus characterized in that an image focused on a plurality of positions of an imaging target can be captured by a single imaging operation by adjusting so as to be different from each other.   5. An image pickup device disposed on the imaging surface is further provided, and an image signal obtained by the image pickup device can be taken out and processed by an external processing device. The multifocal imaging device according to any one of the above.   An image pickup device disposed on the imaging plane; and an image pickup control unit that performs processing for decomposing an image including a plurality of color component images obtained by the image pickup device into a plurality of color component images. The multifocal imaging device according to claim 1, wherein the multifocal imaging device is provided.   The multifocal imaging apparatus according to claim 6, wherein the imaging control unit performs image processing for combining an image decomposed into a plurality of color component images into one image. An objective lens;
A beam splitter having a spectral plane inclined at an angle with respect to the direction of light traveling through the first optical path through the objective lens, and the direction of light reflected by the spectral plane of the beam splitter and traveling through the second optical path A first mirror disposed in a plane perpendicular to the first polarizing plate, and a direction perpendicular to the direction of light passing through the spectral plane of the beam splitter and traveling on the third optical path A second mirror disposed in the plane with a second polarizing plate interposed therebetween, light reflected by the first mirror and transmitted through the spectral plane of the beam splitter, A separation optical system in which both the light reflected by the second mirror and the light reflected by the spectral surface of the beam splitter are imaged on the same imaging plane;
A light emitting means for sequentially illuminating the imaging target with a predetermined time with light of a first polarization direction and a second polarization direction different in polarization direction;
The first polarizing plate in the separation optical system transmits light in the first polarization direction by the light emitting means, and the second polarizing plate transmits light in the second polarization direction. And at least one of the first mirror and the second mirror is disposed so as to be movable in the direction of the optical path, and passes from the objective lens via the first and second optical paths. After adjusting the optical path length of the optical path leading to the imaging plane and the optical path length of the optical path reaching the imaging plane via the first and third optical paths to be different from each other, Imaging with light in one polarization direction reaching the imaging plane via the first and second optical paths by the emission of light and the first and third optical paths by the second light emission by the light emitting means Imaging with light of the other polarization direction that reaches the imaging plane via , Multifocal imaging apparatus being characterized in that as the image focus on different positions meet the imaged subject can be imaged by a series of imaging operations. A beam splitter having a spectral plane that forms an angle with respect to the direction of the light traveling along the first optical path that is the incident optical path of light from the imaging target, and the second optical path reflected by the spectral plane of the beam splitter A first mirror disposed with a first polarizing plate interposed in a plane perpendicular to the direction of traveling light, and light traveling through the third optical path through the spectral plane of the beam splitter. A second mirror disposed in a plane perpendicular to the direction with a second polarizing plate interposed therebetween, and is reflected by the first mirror so that the spectral plane of the beam splitter is A separation optical system in which both the transmitted light and the light reflected by the second mirror and reflected by the spectral surface of the beam splitter are combined,
An objective lens for forming the image of the imaged object on the same image plane when the light combined by the separation optical system is incident;
A light emitting means for sequentially illuminating the imaging target with a predetermined time with light of a first polarization direction and a second polarization direction, each having a different polarization direction;
The first polarizing plate in the separation optical system transmits light in the first polarization direction by the light emitting means, and the second polarizing plate transmits light in the second polarization direction. And at least one of the first mirror and the second mirror is disposed so as to be movable in the direction of the optical path, and passes through the first and second optical paths from the imaging target. The optical path length of the optical path to the objective lens and the optical path length of the optical path to the objective lens via the first and third optical paths are adjusted to be different from each other. Imaging the light with one polarization direction that reaches the imaging plane via the first and second optical paths by light emission, and the first and third optical paths by the second light emission by the light emitting means. Imaging with light of the other polarization direction that reaches the imaging plane via Was carried out, multifocal imaging apparatus being characterized in that as the image focus on different positions meet the imaged subject can be imaged by a series of imaging operations. An objective lens;
A polarization beam splitter having a polarization separation surface that forms an inclined angle with respect to the direction of light traveling through the objective lens and the first light path, and reflected by the polarization separation surface of the polarization beam splitter and traveling along the second light path A first mirror disposed in a plane perpendicular to the direction of light and a plane perpendicular to the direction of light transmitted through the polarization separation surface of the polarization beam splitter and traveling on the third optical path; A second mirror provided, the light reflected by the first mirror and transmitted through the polarization separation surface of the polarization beam splitter, and the light reflected by the second mirror and polarized by the polarization beam splitter. A separation optical system in which both the light reflected by the separation surface and the light reflected on the separation surface are imaged on the same imaging surface;
Light emitting means for sequentially illuminating the imaging target with a predetermined time with light of a first polarization direction and a second polarization light each having a different polarization direction;
The polarization separation surface of the polarization beam splitter of the separation optical system transmits light in one of the orthogonal polarization directions and reflects light in the other polarization direction perpendicular thereto . And at least one of the first mirror and the second mirror is disposed so as to be movable in the direction of an optical path, and the first and second optical paths are passed from the objective lens through the first and second optical paths. After adjusting the optical path length of the optical path to the imaging plane and the optical path length of the optical path to the imaging plane via the first and third optical paths to be different from each other, Imaging the light with one polarization direction that reaches the imaging plane via the first and second optical paths by light emission, and the first and third optical paths by the second light emission by the light emitting means. With the light of the other polarization direction that reaches the imaging plane via Performs an imaging, multifocal imaging apparatus being characterized in that as the image focus on different positions meet the imaged subject can be imaged by a series of imaging operations.
A polarization beam splitter having a polarization separation surface that forms an angle with respect to the direction of light traveling along a first optical path that is an incident light path from the imaging target, and a second light reflected by the polarization separation surface of the polarization beam splitter. A first mirror disposed in a plane perpendicular to the direction of the light traveling on the optical path of the polarization beam splitter and a direction perpendicular to the direction of the light transmitted through the polarization separation surface of the polarization beam splitter and traveling on the third optical path A second mirror disposed in a plane, the light reflected by the first mirror and transmitted through the polarization separation surface of the polarization beam splitter, and reflected by the second mirror and the polarized light A separation optical system in which both the light reflected by the polarization separation surface of the beam splitter and the light are combined,
An objective lens for forming the image of the imaged body on the same image plane when the light combined by the separation optical system is incident;
A light emitting means for sequentially illuminating the imaging target with a predetermined time with light of a first polarization direction and a second polarization direction different in polarization direction;
The polarization separation surface of the polarization beam splitter of the separation optical system transmits light in one of the orthogonal polarization directions and reflects light in the other polarization direction perpendicular thereto . And at least one of the first mirror and the second mirror is disposed so as to be movable in the direction of the optical path, and passes through the first and second optical paths from the imaging target. First light emission by the light emitting means after adjusting the optical path length of the optical path to the objective lens and the optical path length of the optical path to the objective lens via the first and third optical paths. Through the first and second optical paths by the light emission in one polarization direction reaching the imaging plane via the first and second optical paths and the second light emission by the light emitting means. The other polarization direction to the image plane Perform the imaging in the light, multifocal imaging apparatus being characterized in that as the image focus on different positions meet the imaged subject can be imaged by a series of imaging operations.
  12. An image pickup device disposed on the imaging surface is further provided, and an image signal obtained by the image pickup device can be taken out and processed by an external processing device. The multifocal imaging device according to any one of the above.   An imaging device disposed on the imaging surface, a memory for storing and holding an image obtained by the imaging device, and an imaging control unit, and an imaging target obtained by the imaging device by a series of imaging operations The multi-focus imaging apparatus according to claim 8, wherein a plurality of images in focus at different positions in the camera can be stored and held separately.   14. The multifocal imaging apparatus according to claim 13, wherein the imaging control unit performs image processing for combining the plurality of images stored and held separately as one image.   A motor serving as a drive source for moving one of the first mirror and the second mirror in the direction of the optical path, and the optical path length by the movement of the mirror from the rotation angle of the motor in the imaging control unit; An amount of change is obtained, and a calculation is performed to obtain a height as a position difference in the imaged object before and after the change of the optical path length from the amount of change in the optical path length. 15. The apparatus according to claim 1, wherein the combined image is captured once or in a series of imaging operations, and the height of the imaging target can be measured. Multifocal imaging device.

Images