JP2007147951A - Wavefront coding image forming apparatus and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a wavefront coding image forming apparatus achieving further simplification of image processing software for obtaining a final image from a primary image used in a wavefront coding imaging system, thereby reducing the required capacity of a storage medium, and also shortening processing time. <P>SOLUTION: The wavefront coding image forming apparatus has: an optical system constituted of a lens group and a wavefront coding optical system for guiding subject light; and an imaging device photoelectrically converting the subject light transmitted through the optical system, and performs positioning in a rotating direction around an optical axis of the wavefront coding optical system relative to the imaging device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wavefront coding image forming apparatus that is used in a wavefront coding imaging system and has an optical system for obtaining a wavefront coded image.

  2. Description of the Related Art Conventionally, a lens group for guiding subject light, and an imaging device that records the subject image as digital image data by photoelectrically converting subject light transmitted through the lens group by an image sensor and performing predetermined processing. ing.

  There are two types of imaging devices, one that moves the lens group mounted in accordance with the subject distance and performs focus adjustment, and the other that has a fixed focus type in which the lens group is fixed at a position corresponding to a predetermined subject distance.

  The fixed focus type is low-cost, but the shooting distance range is limited to the range that can be covered by the depth of field, and is not suitable for close-up shooting etc. Although it is possible to shoot with good image quality from infinity to a close distance, it also requires a moving mechanism and the like, resulting in an increase in size and cost.

In recent years, as a solution to such a problem, a subject image obtained by using a lens group for image formation and a wavefront coding optical system is photoelectrically converted by an imaging device or the like, and predetermined A / D conversion or the like is performed. By performing further image processing on the image data obtained by performing the above processing, a wavefront coding image that can obtain an image having good sharpness from infinity to a close range while being a fixed focus type A system has been proposed (see, for example, Patent Document 1).
JP 2005-502084 Gazette

  The wavefront coding imaging system of the above-mentioned patent document 1 arranges a wavefront coding optical system composed of a rotationally asymmetric surface with respect to the optical axis at a position where a diaphragm of a lens group for image formation is arranged. Then, image data (this image data is referred to as primary image data) is obtained from the image of the subject thus formed (hereinafter, this image is referred to as primary image), and predetermined image processing is further performed on the primary image data. Thus, image data having good sharpness from infinity to a close distance (hereinafter, this image is referred to as final image data) is obtained. In the following, a unit composed of an imaging optical system composed of the lens group for image formation and the wavefront coding optical system and a lens barrel holding the imaging optical system is referred to as a wavefront coding image forming apparatus. ing.

  Such a wavefront coding imaging system has image processing software for obtaining a final image from a primary image, and includes a wavefront coding optical system composed of a rotationally asymmetric surface with respect to the optical axis and the light of the image sensor. In the case of a wavefront coding image forming apparatus in which the positional relationship in the rotational direction around the axis is not uniform, the image processing software becomes enormous, requires a large amount of processing time, and is impractical. There is a problem.

  In view of the above problems, the present invention can simplify image processing software for obtaining a final image from a primary image used in a wavefront coding imaging system, thereby reducing the required storage medium capacity and processing time. It is an object of the present invention to obtain a wavefront coding image forming apparatus capable of shortening the above.

  The above object is achieved by the invention described below.

  1. An imaging optical system composed of a lens group for guiding subject light and a wavefront coding optical system; and an imaging device that photoelectrically converts subject light transmitted through the imaging optical system, A wavefront coding image forming apparatus, wherein the wavefront coding optical system is positioned in a rotation direction around an optical axis.

  2. 2. The wavefront coding image forming apparatus according to 1, wherein the positioning is performed by a lens barrel that holds the imaging optical system.

  3. 3. The wavefront coding image forming apparatus according to 2, wherein the lens barrel is configured to be able to move linearly in the optical axis direction together with the imaging optical system.

  4. An image pickup apparatus characterized in that a final image is obtained by performing image processing based on an output of an image pickup element constituting the wavefront coding image forming apparatus according to any one of 4.1 to 3.

  According to the present invention, since the positional relationship in the rotation direction around the optical axis of the wavefront coding optical system and the image sensor is uniquely determined, image processing software for obtaining a final image from the primary image used in the wavefront coding imaging system And a wavefront coding image forming apparatus capable of reducing the required storage medium capacity and shortening the processing time, thereby providing an extremely practical wavefront coding imaging system. It becomes possible.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited thereto.

  First, a wavefront coding imaging system including a wavefront coding image forming apparatus according to the present invention will be briefly described.

  FIG. 1 is a block diagram of a wavefront coding imaging system 200 including a wavefront coding image forming apparatus 50 according to the present embodiment.

  As shown in the figure, a wavefront coding image forming apparatus 50 according to the present embodiment transmits an optical system composed of a lens group 51 for image formation and a wavefront coding optical system 52 and the optical system. It is composed of an image sensor 53 that photoelectrically converts subject light and a lens barrel that holds these optical systems. The subject light enters the wavefront coding image forming apparatus 50, passes through the lens group 51 and the wavefront coding optical system 52, and a primary image is formed on the image sensor 53.

  The lens group 51 of the wavefront coding image forming apparatus 50 is an optical system having imaging performance. The wavefront coding optical system 52 is disposed at the position of the stop surface, which is the entrance pupil position of the lens group 51, and has a function of changing the phase of incident subject light. The image pickup element 53 changes the state of the image on the image plane by the wavefront coding optical system 52 and obtains a slightly unclear primary image.

  The imaging device 53 is a solid-state imaging device such as a CCD (Charge Coupled Device) type image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) type image sensor.

  The output from the image pickup device 53 of the wavefront coding image forming apparatus 50 is subjected to processing such as predetermined A / D conversion and becomes primary image data 54.

  The primary image data 54 is subjected to image processing by the image processing means 55, and final image data 56 is obtained. The image processing means 55 restores an image from the primary image data 54 which has been given a wavefront coding by the wavefront coding optical system 52 and has become unclear, thereby obtaining a final image 56 having a deep depth of field and depth of focus. is there. The outline of the wavefront coding imaging system 200 has been described above.

  Hereinafter, an example of a specific configuration of the wavefront coding image forming apparatus 50 will be described.

  FIG. 2 is a cross-sectional view showing a schematic configuration of the wavefront coding image forming apparatus 50 according to the present embodiment.

  In the figure, reference numeral 41 denotes a printed circuit board, and the image sensor 53 is mounted on the printed circuit board 41 by COB (Chip On Board). Signal output from the image sensor 53 and signal input to the image sensor 53 are performed by a circuit (not shown) electrically connected to the printed circuit board 41.

  Reference numeral 42 denotes an outer frame member, which is positioned and fixedly bonded to a light receiving surface of the image pickup device 53 of the printed circuit board 41 at a predetermined position. An infrared light cut filter 43 is bonded and fixed to the outer frame member 42.

  A lens barrel 44 is disposed inside the outer frame member 42. The lens barrel 44 holds a lens group 51 and a disk-shaped wavefront coding optical system 52, and the wavefront coding optical system 52 is disposed at the stop position of the lens group 51. In this example, the object-side surface 52a of the wavefront coding optical system 52 corresponds.

  A key-shaped protrusion 44t is formed at least at one location on the circumferential surface of the lens barrel 44 where the wavefront coding optical system 52 is attached. On the other hand, the disk-like wavefront coding optical system 52 has a key groove-like recess 52m formed at a position corresponding to the protrusion 44t, and the recess 52m and the protrusion 44t are engaged to assemble. . Thereby, the wavefront coding optical system 52 is positioned in the rotational direction with respect to the lens barrel 44.

  Similarly, a key-shaped protrusion 42 t is formed on the cylindrical inner peripheral surface of the outer frame member 42. On the other hand, the cylindrical lens barrel 44 is formed with a key groove-shaped recess 44m at a position corresponding to the protrusion 42t, and the recess 44m and the protrusion 42t are engaged to assemble. Thereby, the lens barrel 44 is rotationally locked by the outer frame member 42.

  A compression coil spring 45, which is an urging member, is incorporated between the outer frame member 42 and the lens barrel 44, and the lens barrel 44 is urged toward the subject by the compression coil spring 45. On the other hand, a female screw portion 42n is formed at the distal end of the outer frame member 42, and a pressing member 46 having a male screw portion 46n that is screwed into the female screw portion 42n is assembled.

  By rotating the holding member 46 and moving it with respect to the outer frame member 42, the lens barrel 44 that contacts the pressing member 46 and the lens group 51 in the lens barrel 44 and the wavefront coding optical system 52 are in contact with the holding member 46. Can be moved straight in the direction of the optical axis O, and the focus position of the imaging optical system with respect to the imaging element 53 can be adjusted.

  As described above, the wavefront coding image forming apparatus 50 according to the present embodiment is positioned in the rotational direction around the optical axis O of the wavefront coding optical system 52 with respect to the imaging element 53. As a result, image processing software for obtaining the final image from the primary image used in the wavefront coding imaging system 200 can be simplified, and the required storage medium capacity can be reduced and the processing time can be shortened. A wavefront coding image forming apparatus can be obtained.

  FIG. 3 is an external view of a mobile phone 100 that is an example of an imaging apparatus incorporating a wavefront coding imaging system including the wavefront coding image forming apparatus according to the present embodiment.

  In the mobile phone 100 shown in the figure, an upper casing 71 as a case having display screens D1 and D2 and a lower casing 72 having an operation button 60 as an input unit are connected via a hinge 73. Yes. The wavefront coding image forming apparatus 50 of the wavefront coding imaging system according to the present embodiment is built below the display screen D2 in the upper casing 71, and the wavefront coding image forming apparatus 50 is outside the upper casing 71. It is arranged to capture light from the surface side.

  The position of the wavefront coding image forming apparatus 50 may be disposed above or on the side of the display screen D2 in the upper housing 71. Of course, the mobile phone is not limited to a folding type.

  FIG. 4 is an example of a functional block diagram of the mobile phone 100 in which the wavefront coding imaging system 200 including the wavefront coding image forming apparatus 50 according to the present embodiment is built.

  As shown in the figure, the cellular phone 100 is a control unit (CPU) 101 that executes overall control of each unit and executes a program corresponding to each process, and an input unit for inputting a number and the like. Operation buttons 60, display screens D1 and D2 for displaying predetermined data display and captured images, a wireless communication unit 80 for realizing various information communication with an external server, a system program for the mobile phone 100, Obtained from a storage unit (ROM) 91 storing various processing programs and necessary data such as a terminal ID, and various processing programs and data executed by the control unit 101, or processing data, and the wavefront coding imaging system 200 A final storage unit (RAM) 92 that temporarily stores final image data and the like, and is used as a work area.

  The final image data input from the wavefront coding imaging system 200 is stored in the storage unit 91 by the control unit 101 of the mobile phone 100, or displayed on the display screens D1 and D2, and further wireless communication is performed. The image information is transmitted to the outside via the unit 80.

  In the above-described embodiment, the module incorporated in the mobile phone is described as an example of the imaging device. However, the present invention is not limited to this, and is not limited to small and thin electronic devices such as PDAs, and imaging of general cameras. Needless to say, the present invention can also be applied to an optical system or the like.

  In addition, the case where the positioning part of the wavefront coding optical system is formed in the shape of a key and a key groove has been described as an example. However, the present invention is not limited to this. Needless to say, the positioning may be performed by the respective formed ones.

1 is a block diagram of a wavefront coding imaging system including a wavefront coding image forming apparatus according to the present embodiment. It is sectional drawing which shows schematic structure of the wavefront coding image forming apparatus which concerns on this Embodiment. 1 is an external view of a mobile phone that is an example of an imaging device that incorporates a wavefront coding imaging system including a wavefront coding image forming apparatus according to the present embodiment. 1 is an example of a functional block diagram of a mobile phone incorporating a wavefront coding imaging system including a wavefront coding image forming apparatus according to the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 41 Printed circuit board 42 Outer frame member 43 Infrared light cut filter 44 Lens barrel 45 Compression coil spring 46 Holding member 50 Wavefront coding image forming apparatus 51 Lens group 52 Wavefront coding optical system 53 Image pick-up device 100 Cell phone 200 Wavefront coding imaging system

Claims (4)

An imaging optical system including a lens group for guiding subject light and a wavefront coding optical system; and an imaging element that photoelectrically converts subject light transmitted through the imaging optical system;
A wavefront coding image forming apparatus, wherein the wavefront coding optical system is positioned with respect to the imaging device in a rotation direction around an optical axis. The wavefront coding image forming apparatus according to claim 1, wherein the positioning is performed by a lens barrel that holds the imaging optical system. The wavefront coding image forming apparatus according to claim 2, wherein the lens barrel is configured to be able to move linearly in the optical axis direction together with the imaging optical system. An image pickup apparatus that performs image processing based on an output of an image pickup element that constitutes the wavefront coding image forming apparatus according to claim 1 to obtain a final image.

Images