JP2004172961A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera in which dust is removed from a photodetector surface without restricting an equipment constitution such as a lens. <P>SOLUTION: When a dust removal button 17 is pressed at the time of a photographing mode, an elevating/lowering device 48 elevates an elevating/lowering plate 42 and makes a cleaning film 50 advance into a photographing optical path L. In this state, driving signals are outputted from a control board to a driving motor and driving shafts 38 and 40 are rotationally driven clockwise. Accompanying it, winding rollers 44 and 46 are also turned in the same direction (arrow A) and the cleaning film 50 is slid and made to travel (arrow B) on the photodetector surface of a CCD 36. The dust stuck to the photodetector surface is peeled off from the photodetector surface by the cleaning film 50 brought into contact with the photodetector surface, adsorbed to the cleaning film 50 and removed from the photodetector surface. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital camera, and more particularly to a digital camera in which imaging is performed by a flat-type imaging device having a light receiving surface.
[0002]
[Prior art]
As is well known, imaging by a digital camera is performed by outputting a subject image formed by a photographing lens as an analog signal on a light receiving surface of a planar imaging device (CCD), and further converting this signal into a digital signal. It is performed by saving / recording on a recording medium such as smart media.
[0003]
However, the conventional digital camera has a drawback that it becomes difficult to capture the original subject image when the attached matter adheres to the light receiving surface of the CCD. That is, for example, in a reflex digital camera (single-lens reflex digital camera) in which a lens barrel consisting of a front end lens group can be replaced, if dust such as dust or dirt enters the inside of the digital camera during the replacement of the lens barrel, The dust adheres to the light receiving surface and the portion is shielded from light. The light receiving surface of the CCD is very small and a large number of light receiving elements are arranged, so even if fine dust adheres to the light receiving surface, the shadow is reflected on the light receiving element, and the pixels in that part are missing. Image defect occurs.
[0004]
In order to cope with this, for example, a digital camera in which a CCD is sealed with a sealing member and dust is prevented from adhering to the light receiving surface (see, for example, Patent Document 1), in front of a shutter curtain provided in front of the CCD, There is known a digital camera provided with a glass for preventing intrusion of dust (see, for example, Patent Document 2).
[0005]
[Patent Document 1]
JP-A-11-109203 [0006]
[Patent Document 2]
JP 2002-90842 A
[0007]
[Problems to be solved by the invention]
However, a digital camera in which a CCD is sealed with a sealing member only has an effect of preventing dust from being captured, and has not yet removed dust. Further, in such a digital camera, there is a restriction on the arrangement configuration of the leading end lens group, so that it has been difficult to apply to a lens interchangeable single-lens reflex digital camera.
[0008]
Further, in a digital camera in which a glass for preventing dust intrusion is installed in front of the shutter film, there is a restriction on the arrangement of mirrors built in the camera body. Further, since such a digital camera restricts the lens configuration of the wide-angle lens, it has been difficult to apply to a range finder camera.
[0009]
The present invention has been made in view of the above points, and an object of the present invention is to provide a digital camera that can remove dust from a light receiving surface without restricting the configuration of a device such as a lens.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an interchangeable lens digital camera in which a planar imaging device having a light receiving surface is arranged in a photographing optical path, a flexible belt having dust adsorbability, And a belt-like body running means for sliding the flexible belt-like body with respect to the light receiving surface.
[0011]
According to the present invention, the dust on the light receiving surface can be removed by sliding the flexible belt having dust adsorbability on the light receiving surface.
[0012]
According to the invention described in claim 2, since the belt-like body traveling means is provided with the belt-like body advancing / retreating means for moving the flexible belt-like body in and out of the photographing optical path. At the time of photographing, the flexible belt-like body is retracted to the outside of the photographing optical path to secure the photographing optical path, and the subject image can be received on the light receiving surface.
[0013]
According to the third aspect of the present invention, since the flexible belt is composed of a translucent cleaning film, the subject image can be obtained even when the cleaning film is positioned in the photographing optical path. Since the light can be received on the light receiving surface through the cleaning film, the photographing optical path can be secured without retracting the flexible strip from the photographing optical path.
[0014]
Further, according to the invention described in claim 4, since the light receiving hole for securing the photographing optical path is formed in the flexible belt, the light receiving hole is positioned on the light receiving surface at the time of photographing. A photographing optical path is secured, and the object image can be received on the light receiving surface. As a result, the photographing optical path can be secured without retracting the flexible band from the photographing optical path, and the subject image can be received on the light receiving surface.
[0015]
According to the fifth aspect of the present invention, since the flexible belt-like body is configured by the cleaning film that electrostatically adsorbs dust, dust on the light receiving surface can be removed. Further, dust attached to the light receiving surface can be adsorbed and removed by the cleaning film without bringing the flexible belt-like body into contact with the light receiving surface.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a digital camera according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a first embodiment of a digital camera 10 according to the present invention.
[0017]
The camera 10 mainly includes a camera body 12, a lens barrel 14, a shutter button 16, and the like.
[0018]
A shutter button 16 and a liquid crystal display unit 18 for displaying shooting status and the like are provided on the top top surface of the camera body 12. In addition, an eyepiece window 20 is disposed at the upper back of the camera body 12. In addition to the main power / mode change switch 15, a dust removal button 17 and the like are provided in the vicinity of the shutter button 16.
[0019]
A lens barrel 14 is detachably attached to the front surface of the camera body 12. The lens barrel 14 is formed in a substantially cylindrical shape as shown in the figure, and an operation ring 28 for operating close-up lenses 22 to 26 to be described later is provided on the outer peripheral surface thereof. . A bayonet mechanism (not shown) is provided inside the lens barrel 14, and a lens mount (not shown) formed on the front surface of the camera body 12 is engaged with the bayonet. The main body 12 is detachable. Since the lens barrel 14 can be replaced, for example, in addition to the telephoto lens shown in the present embodiment, a wide-angle lens or the like can be attached depending on the application.
[0020]
Some lenses in the close-up lenses 22 to 26 are engaged by the above-described operation ring 28 and linear motion means using a cylindrical cam (not shown), and are moved to the photographing optical path (main optical axis) L by rotating the operation ring 28. Moved along. Thereby, the focal length and zoom magnification can be adjusted by the photographer. In addition, a plurality of lenses 28, 28... And reflection mirrors 30, 32 are provided inside the camera body 12 and are arranged on the optical path from the close-up lenses 22 to 26 to the eyepiece window 20. This enables visual confirmation of the subject through the eyepiece window 20.
[0021]
A CCD 36 mounted on the circuit board 34 is disposed at the imaging position of the lenses 22 to 26 on the photographing optical path L. The CCD 36 has a light receiving surface on which a large number of light receiving elements are arranged, and is attached to the circuit board 34 with the light receiving surface facing the front of the digital camera 10, that is, toward the lenses 22 to 26. In addition, a low-pass filter, an infrared filter (not shown) or the like is attached to the surface of the light receiving surface of the CCD 36, and even if a cleaning film 50 described later is slid on the light receiving surface, the light receiving surface is damaged. It is good also as a structure which attached the protective glass which does not produce etc.
[0022]
Here, the reflection mirror 30 is provided with a rotation mechanism (not shown) that rotates the reflection mirror 30. As shown in the figure, the reflecting mirror 30 advances into the photographing optical path L and secures an optical path to the eyepiece window 20, so that the subject image cannot be received on the light receiving surface of the CCD 36 in this state. Then, the reflecting mirror 30 is rotated to a predetermined angle by this rotating mechanism, the photographing optical path L to the light receiving surface is secured, and the subject image can be received on the light receiving surface.
[0023]
The circuit board 34 is provided with an imaging signal processing circuit connected in circuit with the CCD 36, and an analog signal imaged by the CCD 36 is processed by the imaging signal processing circuit and converted into digital data.
[0024]
A lifting plate 42 is provided in the vicinity of the circuit board 34. As shown in the figure, the elevating plate 42 is formed in a substantially U-shape avoiding interference with the circuit board 34 and the like, and an elevating device 48 provided in the vicinity of the elevating plate 42 via a support member 49. It is supported so that it can be raised and lowered. The elevating device 48 incorporates a sensor (not shown) that detects that the elevating plate 42 is in the raised position and the lowered position.
[0025]
Drive shafts 38 and 40 are provided on the upper surface of the lift plate 42. The drive shafts 38 and 40 are arranged so that their rotational axes are parallel to the light receiving surface of the CCD 36. Further, winding rollers 44 and 46 are detachably mounted on the drive shafts 38 and 40, respectively. Further, the drive shafts 38 and 40 incorporate a drive motor (not shown), and can rotate the winding rollers 44 and 46 attached to the drive shafts 38 and 40. The drive shafts 38 and 40 have timing belts (not shown), and are configured such that the rotation directions and the rotation speeds of the winding rollers 44 and 46 are linked.
[0026]
A cleaning film 50 that constitutes a flexible belt-like body is wound around the winding rollers 44 and 46. The cleaning film 50 is subjected to a surface treatment that does not cause scratches on the light receiving surface even when it is slid on the light receiving surface. Since the cleaning film 50 can be detached from the drive shafts 38 and 40 together with the winding rollers 44 and 46, for example, the cleaning film 50 can be replaced even when the dust removing performance is deteriorated.
[0027]
When an abnormality such as a tensioner (not shown) that can finely adjust the cleaning film 50 to a predetermined position or an abnormality such as breakage of the cleaning film 50 occurs while the predetermined tension is applied to the cleaning film 50, A film cutting detection sensor (not shown) that can detect the above is provided.
[0028]
The circuit board 34 is provided with a control device that comprehensively controls the camera 10. This control device is connected to each operation device such as the shutter button 16 described above, the CCD 36, the liquid crystal display unit 18 and the like via a circuit (not shown), and the shutter button 16 and the dust removal button 17 by the photographer are connected. A corresponding instruction signal is output to the built-in device based on a pressing operation or the like. In particular, this control device is also connected to a drive motor for driving the drive shafts 38 and 40, a lifting device 48, and the like, and outputs a drive signal to these devices.
[0029]
In addition, a reader / writer device 52 connected to the control device in a circuit is provided inside the camera body 12. In this reader / writer device 52, a memory card 54 for recording and storing digital data is detachably inserted. For example, when there is a recording instruction input by pressing the shutter button 16 in the photographing mode, imaging signal processing is performed. Digital data processed by the circuit can be recorded and stored in the memory card 54 via the reader / writer device 52. In the reproduction mode, digital data stored in the memory card 54 is read out via the reader / writer device 52 by the imaging signal processing circuit. In the present embodiment, for example, smart media is used as the memory card 54. However, the present invention is not limited to this, and an XD picture card, PC card, flash memory card, or the like may be used as a recording medium. Note that the memory card 54 can be removed from the camera body 12 by opening and closing the door 56 provided on the side surface of the camera body 12, whereby the memory card 54 can be replaced.
[0030]
A monitor display unit (not shown) is provided below the eyepiece window 20 on the back of the camera body 12. This monitor display unit is mounted on the back surface of the circuit board 34 together with a backlight for illuminating the monitor display unit, and is arranged so as to expose the display surface of the monitor display unit from a rectangular window opened in the area of the camera body 12. Has been. The monitor display unit displays an image recorded on the memory card 54, various setting screens, and the like.
[0031]
When shooting is performed using the digital camera 10 having such a configuration, first, the main power / mode switch 15 is switched to set the shooting mode. Thereafter, the photographer captures the subject through the eyepiece window 20, operates (framing) the camera 10 so that the subject is within the photographing range, and presses the shutter button 16 to perform imaging.
[0032]
After the photographer operates the operation ring 28 to adjust the focal length and zoom magnification by the close-up lenses 22 to 26, the shutter button 16 is pressed halfway to perform focusing and exposure control. Further, after confirming the focus and exposure with the eyepiece window 20, the shutter button 16 is fully pressed to take an image. Digital data of the captured still image is recorded and stored in the memory card 54. In the photographing mode, the elevating plate 42 is always in the lowered position.
[0033]
When the main power / mode change-over switch 15 is switched to set the playback mode, the digital data stored in the memory card 54 is read out via the reader / writer device 52 and is displayed as a playback image on the monitor display unit. Although displayed, detailed description of these playback modes is omitted.
[0034]
Next, the operation of the dust removal on the light receiving surface using the digital camera 10 configured as described above will be described. In particular, when the lens barrel 14 is replaced, it is desirable to perform this removal operation.
[0035]
First, the main power / mode changeover switch 15 is switched to enter the photographing mode. Next, the dust removal button 17 is pressed. Along with this, the control device switches to the dust removal mode, and the operation of each operation device in the digital camera 10 is not accepted during the dust removal.
[0036]
When switching to the dust removal mode, the control device outputs a drive signal for raising the lifting plate 42 to the lifted position to the lifting device 48, and the lifting device 48 lifts and lowers until the lifted position of the lifting plate 42 is detected by the sensor. The plate 42 is raised. Then, the cleaning film 50 advances into the photographing optical path L as shown in FIG.
[0037]
Next, the position of the cleaning film 50 is adjusted by a tensioner provided on the elevating plate 42 so that the cleaning film 50 contacts the light receiving surface. In this state, a drive signal is output from the control device to the drive motor, and the drive shafts 38 and 40 are driven to rotate clockwise. As a result, the winding rollers 44 and 46 are also rotated in the same direction (arrow A), and the cleaning film 50 slides on the light receiving surface of the CCD 36 (arrow B). The dust adhering to the light receiving surface is peeled off from the light receiving surface when the cleaning film 50 contacts the light receiving surface, and is adsorbed by the cleaning film 50 and removed from the light receiving surface. In addition, it is good also as a structure which gives a raising process etc. to the surface of the cleaning film 50, and makes this raising contact a light-receiving surface.
[0038]
After the elapse of a predetermined time (about 2 to 4 seconds) set in advance, the drive motor is stopped by the control device, and a drive signal for lowering the elevating plate 42 to the lowered position is output to the elevating device 48. The lifting device 48 lowers the lifting plate 42 until the lowered position is detected by the sensor. At this time, the position of the cleaning film 50 is adjusted by a tensioner provided on the elevating plate 42 so that the light receiving surface and the cleaning film 50 maintain a predetermined gap. As a result, the cleaning film 50 moves backward out of the photographing optical path L to secure the photographing optical path L, and the object image can be received on the light receiving surface of the CCD 36. Thereafter, the control device releases the dust removal mode. Note that the position of the cleaning film 50 is adjusted by the above-described tensioner so that the light receiving surface and the cleaning film 50 do not interfere when the elevating plate 42 is raised and lowered.
[0039]
With the digital camera 10 having such a configuration, it is possible to remove the dust on the light receiving surface by sliding the cleaning film 50 on the light receiving surface. In particular, since the cleaning film 50 is moved forward and backward in the photographing optical path and outside the photographing optical path by the elevating plate 42 that raises and lowers the winding rollers 44 and 46, the cleaning film 50 is retracted to the outside of the photographing optical path during photographing. And the object image can be received on the light receiving surface.
[0040]
Next, a second embodiment of the digital camera according to the present invention will be described. In this embodiment, a translucent cleaning film is used as the flexible strip.
[0041]
As this cleaning film, for example, polyvinyl chloride or polyethylene whose surface is treated with an adsorbing property such as dust is used. By sliding the cleaning film having such a configuration on the light receiving surface of the CCD, dust adhering to the light receiving surface is peeled off from the light receiving surface, and is adsorbed by the cleaning film and removed from the light receiving surface. Further, even when the cleaning film is positioned in the photographing optical path L (see FIG. 1), the subject image passes through the cleaning film and can be received on the light receiving surface. When no moving means is provided, dust can be removed from the light receiving surface by using this cleaning film.
[0042]
Furthermore, a third embodiment of the digital camera according to the present invention will be described. In the present embodiment, a cleaning film that electrostatically adsorbs dust is used as the flexible strip.
[0043]
This cleaning film is composed of, for example, a synthetic fiber fabric including at least a part of a chargeable yarn. In particular, the synthetic fiber is preferably a material that is easily charged, such as polyester, and is formed in a plain weave shape. As the warp and weft, chargeable yarns are inserted at a predetermined pitch. When this cleaning film is brought close to other uncharged conductors, a charge having the opposite sign to the charge charged on the cleaning film appears on the latter surface. Other conductors, that is, dust and the like can be adsorbed to the cleaning film due to the electrostatic adsorbability generated thereby. By sliding the cleaning film having such a configuration on the light receiving surface of the CCD, dust adhering to the light receiving surface is peeled off from the light receiving surface, and is adsorbed by the cleaning film and removed from the light receiving surface. In the present embodiment, dust can be electrostatically adsorbed and removed while maintaining a predetermined gap without bringing the cleaning film into contact with the light receiving surface. Thereby, for example, dust adsorbed on the cleaning film can be prevented from sliding on the light receiving surface and causing scratches.
[0044]
Next, FIG. 2 shows a fourth embodiment of the digital camera according to the present invention. In the digital camera 80 in the figure, the same members as those in the digital camera 10 in FIG. 1 are denoted by the same reference numerals.
[0045]
Drive shafts 88 and 90 are provided inside the camera body 12 of the digital camera 80. The drive shafts 88 and 90 are arranged so that their rotational axes are parallel to the light receiving surface of the CCD 36. The drive shafts 88 and 90 include a drive motor (not shown) connected to the control device of the circuit board 34, and the control device controls the unwind roller 84 and the take-up roller 86 attached to the drive shafts 88 and 90. The rotation can be controlled by.
[0046]
A cleaning film 92 is wound around the unwinding roller 84 and the winding roller 86, and the cleaning film 92 drawn from the unwinding roller 84 is wound around the winding roller 86 and wound. Yes.
[0047]
A set of guide rollers 82, 82... Is provided on the circuit board 34, and these rollers are arranged at the ends (two places on the left and right) of the circuit board 34. The guide rollers 82, 82... Are arranged so that their rotational axes are parallel to the light receiving surface of the CCD 36, respectively. The guide rollers 82 and 82 are provided with tensioners (not shown) that can apply a predetermined tension to the cleaning film 92 and finely adjust the cleaning film 92 to a predetermined position.
[0048]
Here, the cleaning film 92 used in the present embodiment is obtained by forming the light receiving holes 94, 94... In the cleaning film 50 used in the first embodiment described above. The light receiving holes 94, 94... Are arranged at a predetermined interval with respect to the longitudinal direction of the cleaning film 92, and are arranged at positions corresponding to the light receiving surface of the cleaning film 92. Further, the size of the light receiving hole 94 is slightly larger than the light receiving surface as shown in FIG. The circuit board 34 is provided with a sensor 95 for detecting the position of the light receiving hole 94, and the light receiving hole 94 and the control device for the circuit board 34 are connected via a circuit (not shown). Thereby, in the control device, the position of the light receiving hole 94 can be recognized. In addition, a remaining amount detection sensor (not shown) for detecting the remaining amount of the cleaning film 92 in the unwinding roller 84, a film cutting detection sensor (not shown), and the like are provided in the vicinity of the unwinding roller 84. Yes.
[0049]
In the digital camera 80 configured as described above, in the photographing mode and the reproduction mode, the control device controls the position of one of the light receiving holes 94, 94... To coincide with the light receiving surface of the CCD 36. The In the control device, the position of the light receiving hole 94 is controlled by rotationally driving the winding roller 84 and the winding roller 86 based on the detection result of the sensor 95. As a result, the photographing optical path L is secured, and the object image can be received on the light receiving surface.
[0050]
Next, after the main power / mode changeover switch 15 is switched to enter the photographing mode, the dust removal button 17 is pressed to enter the dust removal mode.
[0051]
When switched to the dust removal mode, a drive signal for rotating the winding roller 84 and the winding roller 86 in the clockwise direction is output from the control device. As a result, the unwinding roller 84 and the winding roller 86 are rotationally driven (arrow C), and the cleaning film 92 travels (arrow D). At this time, dust adhering to the light receiving surface is peeled off from the light receiving surface when the portion 92a of the cleaning film 92 contacts the light receiving surface, and is adsorbed by the cleaning film 92 and removed from the light receiving surface.
[0052]
Thereafter, the winding roller 84 and the winding roller 86 are rotationally driven by the control device until the position of the light receiving hole 94 coincides with the light receiving surface. At this time, the position of the light receiving hole 94 is detected by the sensor 95, and when the control device determines that the position of the light receiving hole 94 coincides with the light receiving surface, the drive motor is stopped by the control device. . Thereby, the photographing optical path L to the light receiving surface is secured, and the subject image can be received on the light receiving surface.
[0053]
According to the digital camera 80 having such a configuration, since the light receiving holes 94 for securing the photographing optical path L are formed in the cleaning film 92 at a predetermined interval, the light receiving holes 94 are formed on the light receiving surface during photographing. The photographing optical path L is secured by positioning, and the object image on the light receiving surface can be received.
[0054]
Note that the structure of the digital camera described in the above embodiment is not limited to the above embodiment. For example, a dust cleaning brush for cleaning dust adhering to the surface of the cleaning film may be provided in the vicinity of the circuit board 34. As a result, it is possible to extend the replacement cycle of the flexible belt-like body while minimizing the deterioration of the dust removal performance of the cleaning film.
[0055]
Further, a dust detection sensor for detecting dust adhering to the light receiving surface of the CCD 36 is disposed in the vicinity of the circuit board 34, and when the dust on the light receiving surface is detected by the dust removal sensor, the cleaning film slides. Also good. This dust removal sensor is connected to the control device of the circuit board 34, and the detection result of dust is output to the control device. In the control device, when dust on the light receiving surface is detected by the dust removal sensor, the cleaning film is slid to remove dust on the light receiving surface. Thereby, it is possible to automatically remove dust from the light receiving surface without providing the dust removal button 17.
[0056]
【The invention's effect】
As described above, according to the digital camera of the present invention, the dust on the light receiving surface can be removed by sliding the flexible belt having dust adsorbability on the light receiving surface.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a digital camera according to an embodiment of the present invention. FIG. 2 is a perspective view showing another embodiment of the digital camera according to the embodiment of the invention. ]
DESCRIPTION OF SYMBOLS 10,80 ... Digital camera, 12 ... Camera body, 17 ... Dust removal button, 36 ... CCD, 42 ... Lifting plate, 44, 46 ... Winding roller, 48 ... Lifting device, 50, 92 ... Cleaning film, 84 ... Winding Take-out roller, 86 ... take-up roller, 94 ... light receiving hole, L ... photographing optical path

Claims (5)

In an interchangeable-lens digital camera in which a planar image sensor having a light-receiving surface is arranged in the photographing optical path,
A flexible belt with dust adsorbability;
A digital camera comprising: a belt-like body running means for sliding the flexible belt-like body with respect to the light receiving surface. In the belt-like body traveling means,
2. The digital camera according to claim 1, further comprising a belt-like body advancing / retreating means for moving the flexible belt-like body forward and backward in and out of the photographing optical path. The flexible strip is
The digital camera according to claim 1, wherein the digital camera is a translucent cleaning film. In the flexible strip,
The digital camera according to claim 1, wherein a light receiving hole for securing the photographing optical path is formed. The flexible strip is
5. The digital camera according to claim 1, wherein the digital camera is a cleaning film that electrostatically adsorbs dust.

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