JP4328808B2 - Imaging device - Google Patents

Description

  The present invention relates to an image pickup apparatus provided in a camera or the like and having a photographing lens.

  Conventionally, a film camera using a silver salt film has been widely used, but in recent years, a digital camera capable of capturing an image in a memory without using a film has been rapidly spread. In general, an image sensor such as a CCD or a CMOS is used as an image sensor used in a digital camera.

  Among these digital cameras, there is an infrared cut filter that cuts infrared light having a spectral sensitivity of the image sensor, and a moire that is generated in a subject photographed image by a frequency component related to the pixel pitch of the image sensor. And a low-pass filter for preventing false colors. In some cases, an infrared cut coating is applied on a low-pass filter instead of the infrared cut filter.

  Infrared cut filters and low-pass filters are usually placed directly above the optical axis of the image sensor. A sheet having a mask for cutting harmful light is first dropped into a box-shaped ground plane having an opening, and then the above filter is used. Drop. And a filter is hold | maintained by fixing a filter and a ground plane with an adhesive agent etc.

  Further, behind the filter, an imaging range is surrounded by an elastic member made of rubber or the like between the ground plate and the protective glass on the front surface of the imaging device so that dust or the like does not enter the imaging surface from the surroundings.

  FIG. 11 is a cross-sectional view of the periphery of an imaging element of a conventional imaging device.

  In the figure, the optical member holding means 11, the image sensor holding means 12, the image pickup element 13, the masking means 14 for determining the amount of light incident on the image pickup element 13 and blocking harmful light, the optical rope filter and the infrared cut. An optical member 15 such as a filter is shown. Further, impurity intrusion prevention means 16 and photographing optical means 17 made of an elastic body such as rubber are shown.

  As can be seen from the drawing, an optical member receiving portion 11a is provided in front of the optical axis of the optical member holding means 11, and a mask means 14 and an optical member 15 are placed therein. Here, the optical member 15 is fixed to the optical member holding means 11 with an adhesive.

  An imaging element 13 that is bonded and fixed to the imaging element holding means 12 is disposed on the back surface of the optical member 15, and dust or the like is present on the light receiving surface of the imaging element 13 between the imaging element 13 and the optical member holding means 11. Impurity intrusion prevention means 16 for preventing intrusion is provided. The photographic optical means 17 including the photographic lens 18 is arranged on the front surface of this configuration.

  With the above configuration, the distance in the direction of the thickness spectral axis of the optical member receiving portion 11a increases, and even if the photographing lens 18 is as close as possible to the optical member 15 as shown in FIG. As a result, the distance becomes thicker. Various proposals have been made to reduce these distances.

Patent Document 1 and Patent Document 2 propose a structure that can reduce the length in the optical axis direction and reduce the thickness in the optical axis direction as a whole of the optical system in an optical system having an optical filter. .
JP 2006-67356 A JP 2005-12334 A

  In the above-mentioned Patent Document 1, mask means and an optical member are incorporated into an optical filter holding means made of a metal sheet metal having two bent portions, and are inserted from the back of a so-called CCD holder. In this way, since only the mask means and the sheet metal-like optical filter holding means are present on the front surface of the optical filter, it is possible to achieve a thinner thickness in the optical axis direction than the conventional structure.

  However, in this case, the optical filter holding means has a step-like complicated shape, and there is a problem that the thickness of both the mask means and the optical filter holding means cannot be reduced.

  In Patent Document 2, the optical filter holding means is made of an elastic member such as rubber on the configuration of Patent Document 1. In this case, the accuracy of the elastic member is difficult to stabilize, As a result, the position of the optical member fluctuates.

  An object of the present invention is to provide an imaging apparatus that can be thinned in the optical axis direction.

In order to achieve the above object, an imaging apparatus according to claim 1 is an optical member, optical member holding means for holding an imaging element for converting a subject image into an electrical signal, and in front of an optical axis of the optical member. A mask unit that is fixed to the optical member holding unit and limits an incident light amount of a subject light beam; an imaging device that is behind the optical axis of the optical member and converts a subject image into an electrical signal; the imaging device; and an elastic member is an elastic body provided between the optical member, the optical member is held side by the optical member holding means is holding the light incident surface by the mask means Rutotomoni, the elastic member It is sandwiched between the back surface of the optical member and the front surface of the image sensor .

  An image pickup apparatus according to the present invention includes an optical member, an optical member holding unit, a mask unit that is in front of the optical axis of the optical member, is held on the front surface of the optical member holding unit, and limits the amount of incident light of the subject light beam, And an image sensor for converting a subject image into an electrical signal. Further, an impurity intrusion prevention unit for preventing intrusion of impurities from the periphery is provided between the image pickup element and the optical member. The optical member has a light incident surface held by a mask unit and a side surface held by the optical member holding unit.

  With this configuration, it is possible to reduce the thickness in the optical axis direction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an external perspective view showing a state in which a digital camera according to an embodiment of the present invention is turned off. FIG. 2 is an external perspective view showing a state in which the power supply of the digital camera according to the embodiment of the present invention is turned on. FIG. 3 is a top view of the digital camera according to the embodiment of the present invention. FIG. 4 is a rear view of the digital camera according to the embodiment of the present invention. FIG. 5 is a bottom view of the digital camera according to the embodiment of the present invention. FIG. 6 is a block diagram of the digital camera according to the embodiment of the present invention.

  A digital camera 19 as an image pickup apparatus shown in this embodiment has a zoom mechanism that can change a shooting magnification.

  A finder 24 that determines the composition of the subject, an auxiliary light source 23 that assists the light source when performing photometric distance measurement, a strobe 25, and a photographic lens barrel 26 are configured in front of the digital camera 19.

  A release button 20, a power switch button 22, a zoom switch 21 on the top surface, a tripod mounting portion 35, a memory card drive 49 (FIG. 6), and a battery insertion portion (not shown) on the bottom surface. A battery cover 36 is disposed.

  Operation buttons 29, 30, 31, 32, 33, and 34 are arranged on the back surface, and various function switching can be performed. Further, a display 28 made of an LCD and a viewfinder eyepiece 27 are disposed on the back surface.

  The operation buttons 29, 30, 31, 32, 33, and 34 are used to select an operation mode of the digital camera 19, such as a shooting mode, a playback mode, and a moving image shooting mode.

  The display 28 is image display means, and displays the image data stored in the memory 47 (FIG. 6) and the image data read from the memory card on the screen. In addition, when a mode is selected, a plurality of shooting data can be reduced and displayed on the screen.

  In FIG. 6, the control unit includes a CPU 53, a ROM 52, and a RAM 54, and various components such as a release button 20, operation buttons 29 to 34, a display 28, a memory 47, and a memory card drive 49 are connected via a bus 51. Yes.

  The driving circuit 50 connected to the control system via the bus 51 is connected with a zoom motor driving unit 37, a focus motor driving unit 39, a shutter driving unit 41, an image sensor 8 such as a CCD or a CMOS, and a strobe 25. Each drive is controlled by a signal from the control system.

  The ROM 52 stores a program for controlling each functional component described above. The RAM 54 stores data necessary for each control program.

  As shown in FIG. 6, the digital camera 19 includes a focusing unit 38, a shutter unit 40, a diaphragm unit 42, a diaphragm driving unit 43, an analog signal processing unit 44, an A / D conversion unit 45, a digital signal processing unit 46, A compression / expansion means 48 is provided.

  As described above, the digital camera 19 according to the present embodiment is configured. However, when the user turns on the power by operating the power switch button 22, the CPU 53 reads a necessary control program from the ROM 52. To start the initial operation. That is, the photographing lens barrel 26 is moved to a predetermined photographing possible area, the photographing function is activated, and the photographing standby state is set.

  When the release button 20 is pressed to take a picture, the brightness of the subject is detected by the image sensor 8, and based on the photometric value, it is determined whether the aperture value, shutter speed, and strobe 25 are to be emitted. In addition, the user can select whether the strobe 25 is forced to emit light or not by using the operation button 30 in advance.

  Next, distance measurement is performed, the distance to the subject is measured, and the focus motor drive means 39 is driven to move the focus means 38 to a predetermined focus position. Next, the shutter unit 40 is opened and closed, and a desired image is taken into the image sensor 8.

  In the image pickup device 8, charges corresponding to the amount of incident light are accumulated based on the exposure control value, and the charges become an image signal and are output to the analog signal processing means 44.

  The analog signal processing unit 44 performs analog processing on the captured image data and outputs it to the A / D conversion unit 45. The A / D converter 45 converts the captured analog data into digital data. This digital data is output to the digital signal processing means 46, where the digital data is processed. Finally, the digital data is stored in the memory 47.

  Data stored in the memory 47 is subjected to compression processing such as JPEG or TIFF by the compression / expansion means 48 by the operation of the operation button 31, and is output and stored in the memory 47.

  In the case of a digital camera that does not have the memory 47, the digital data processed by the digital signal processing means 46 is output to the compression / expansion means 48 and stored in the memory card drive 49.

  The image data stored in the memory 47 and the image data stored in the memory card drive 49 can be decompressed by the compression / expansion means 48, and the image data can be displayed on the display 28 via the bus 51. When the user views the data on the display 28 and determines that the image is unnecessary, the user can delete the image by operating the operation button 32.

  A zoom changeover switch 21 is arranged on the upper surface, and the zoom changeover switch 21 is operated to control the zoom motor drive means 37 via the drive circuit 50 to move the photographing lens barrel 26 in the optical axis direction of the lens. Let

  Further, the stored image displayed on the display 28 can be enlarged and reduced by the operation of the zoom changeover switch 21, so-called digital zoom.

  Next, the configuration of the image sensor holding unit provided in the photographing lens barrel 26 provided in the digital camera 19 according to the present embodiment will be described.

  7 is a rear perspective view of the image sensor holding unit in the digital camera of FIG. 1, and FIG. 8 is a front perspective view of the image sensor holding unit in the digital camera of FIG.

  In general, components are assembled in front of and behind an optical member holding means 1 called a CCD holder. A mask means 2 having a mask portion 2b for limiting the amount of incident light from the front of the optical member holding means 1 and cutting harmful rays is incorporated.

  For assembling, the mask means 2 is provided with a snap fit means 2a, the optical member holding means 1 is provided with a snap fit means 1a, and the snap fit means 2a is locked to the snap fit means 1a, The optical member holding means 1 and the mask means 2 are fixed.

  The mask means 2 is made of a thin plate metal or the like, and the thickness is desirably 0.1 mm or less. In addition, a partially bent shape is provided to increase the strength. The mask means 2 is black coated with antireflection on the whole. As described above, the mask function is improved.

  An optical member 3 that is an optical filter is incorporated into the unit in which the mask means 2 is incorporated in the optical member holding means 1 from the back surface shown in FIG. The front surface of the optical member 3 is held by the mask means 2, and the four side surfaces are held by the optical holding means 1.

  Further, an impurity intrusion prevention means 4 made of an elastic member is incorporated on the back surface, and an image sensor holding means 5 for adhering and fixing an image sensor 8 such as a CCD from the back surface. The impurity intrusion prevention means 4 is sandwiched between the back surface of the optical member 3 and the front surface of the image sensor 8, and a series of components are obtained by fixing the image sensor holding means 5 to the optical member holding means 1 by the image sensor holding and fixing means 7. Will be retained.

  Here, the front of the optical member 3 (the left side in the figure, the photographing lens side) is the front of the optical axis, and the rear of the optical member 3 (the right side of the figure, the image sensor side) is the rear of the optical axis. The light incident surface of the optical member 3 is the front surface, that is, the surface facing the photographing lens 10.

  With such a configuration, impurities such as dust do not enter the optical member 3 and the image sensor 8. Further, by interposing a plurality of spring-shaped imaging element pressing means 6 between the imaging element holding means 5 and the optical member holding means 1, a force is applied to the imaging element holding means 5 in a direction away from the optical member holding means 1. It takes. With this configuration, the position of the image sensor 8 can be adjusted.

  With the above configuration, as shown in FIG. 11, unlike the conventional configuration in which the photographic optical means 17 is increased in distance by the thickness of the optical member receiving portion 11a, the overall thin photographic lens barrel 26 is configured. it can.

  FIG. 9 is a cross-sectional view of the periphery of the image sensor of the digital camera of FIG.

  As shown in FIG. 9, the photographing optical means 9 including the photographing lens 10 constituting a part of the photographing lens barrel 26 is arranged in front of the mask means 2 and the optical member holding means 1, but the photographing optical means. 9 is in a state in which it can approach the optical member holding means 1 as compared with the conventional state of FIG.

  The photographing optical means 9 is provided with a protrusion 9a. When the photographing optical means 9 further approaches the optical member holding means 1, the protrusion 9a pushes the front surface of the mask means 2 and elastically deforms the mask means 2. Thus, the optical member 3 is retracted backward.

  If it does in this way, it can prevent that photography lens 10 and optical member 3 collide directly. Alternatively, the protrusion 9a may be brought into direct contact with the optical member 3 and the optical member 3 may be retracted backward. When the photographing optical means 9 moves forward (leftward in FIG. 9), it can be returned to the initial position by the elastic force of the impurity intrusion prevention means 4, which is an elastic body on the back surface of the optical member 3.

  In this way, even if the photographing optical means 9 is excessively pulled in due to component variations, control variations, or external impacts, the photographing lens 10 and the optical member 3 can be prevented from being destroyed.

  Even if the optical member 3 is designed to be retracted by the photographing optical means 9 from the beginning, there is an advantage that the photographing lens barrel 26 can be made thin.

  FIG. 10 is a flowchart showing a procedure of photographing processing executed by the digital camera of FIG.

  This process is executed by the CPU 53 in FIG.

  In FIG. 10, when the user turns on the power of the digital camera (imaging device) 19 (step S101), a command is sent from the CPU 53 to the zoom motor drive means 37, and the lens barrel drive motor is rotated CW (step S102). Thereafter, a predetermined operation is performed, and when it is confirmed that the photographing lens barrel 26 has moved to the photographing position, it is stopped (step S103). At this time, the state of the photographic lens barrel 26 changes from the state of FIG. 1 to the state of FIG.

  Next, when the user turns on the release button 20 (step S104), photometry is performed to obtain luminance information of the subject (step S105). When the obtained luminance is higher than the predetermined luminance (YES in step S106), the diaphragm means 42 is entered (inserted) into the optical axis to change the amount of incident light (step S107). When the obtained luminance information is lower than the predetermined luminance, the diaphragm means 42 is not operated and is kept away from the optical axis.

  Thereafter, the focusing means 38 is operated to move the photographic lens barrel 26 to a position where the subject is in focus (step S108), where image capture is started (step S109).

  Next, the shutter means 40 is moved from the open state to the closed state (step S110), the incident light quantity is blocked, and the image capturing is completed (step S111). Thereafter, the diaphragm means 42 is retracted from the optical axis (step S112), the focus means 38 is moved to the initial position (step S113), and the process is terminated.

  In the present embodiment, the optical member 3 and the photographing lens 10 are optical filters even when the photographing lens 10 is thin in the optical axis direction and the photographing lens 10 is excessively retracted due to component variations, control variations, external impact, or the like. Therefore, it is possible to obtain the photographing lens barrel 26 that does not break. In addition, an imaging apparatus including the photographing lens barrel 26 can be provided.

  Although an example of a digital camera is shown in this embodiment mode, a video camera having a similar lens barrel structure, an analog camera using a silver salt film, and the like can have the same configuration.

It is an external appearance perspective view which shows the state which turned off the power supply of the digital camera which concerns on embodiment of this invention. It is an external appearance perspective view which shows the state which turned on the power supply of the digital camera which concerns on embodiment of this invention. 1 is a top view of a digital camera according to an embodiment of the present invention. It is a rear view of the digital camera which concerns on embodiment of this invention. It is a bottom view of the digital camera which concerns on embodiment of this invention. It is a block block diagram of the digital camera which concerns on embodiment of this invention. FIG. 2 is a rear perspective view of an image sensor holding unit in the digital camera of FIG. 1. FIG. 2 is a front perspective view of an image sensor holding unit in the digital camera of FIG. 1. It is sectional drawing of the image pick-up element periphery of the digital camera of FIG. It is a flowchart which shows the procedure of the imaging | photography process performed with the digital camera of FIG. It is sectional drawing of the image pick-up element periphery of the conventional image pick-up device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical member holding means 1a Snap fit means 2 Mask means 2a Snap fit means 2b Mask part 3 Optical member 4 Impurity intrusion prevention means 5 Imaging element holding means 6 Imaging element pressing means 7 Imaging element holding fixing means 8 Imaging element 9 Imaging optics Means 10 Shooting lens 19 Shooting device (digital camera)
20 Release button 21 Zoom switch 22 Power switch button 23 Auxiliary light source 24 Viewfinder 25 Strobe 26 Shooting lens barrel 27 Viewfinder eyepiece 28 Display 29 to 34 Operation button 35 Tripod attachment 36 Card battery cover 37 Zoom motor drive means 38 Focus means 39 Focus motor drive means 40 Shutter means 41 Shutter drive means 42 Aperture means 43 Aperture drive means 44 Analog signal processing means 45 A / D converter 46 Digital signal processing means 47 Memory 48 Compression / expansion means 49 Memory card drive 50 Drive circuit 51 Bus 52 ROM
53 CPU
54 RAM

Claims (3)

An optical member;
Optical member holding means for holding an image sensor that converts a subject image into an electrical signal ;
Mask means that is in front of the optical axis of the optical member, is fixed to the optical member holding means, and limits the amount of incident light of the subject light beam;
An image sensor that is behind the optical axis of the optical member and converts a subject image into an electrical signal;
An elastic member that is an elastic body provided between the imaging element and the optical member;
The optical member is held side by the optical member holding means is holding the light incident surface by the mask means Rutotomoni, said elastic member being sandwiched in front of the imaging device and the rear of the optical member An imaging device that is characterized.   The optical member also moves in accordance with the photographing optical means when the photographing optical means in front of the optical axis of the optical member moves relative to the optical member holding means. The imaging apparatus according to 1.   When the photographing optical means in front of the optical axis of the optical member moves relative to the optical member holding means, the mask means and the optical member also move according to the photographing optical means. The imaging apparatus according to claim 1.

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