JP2004145144A - Photographing apparatus and lens system used for same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photographing apparatus which is easy to assemble and decreased in number of components and has superior shock resistance and dustproof property without exerting any adverse influence on images and a lens system used for the same. <P>SOLUTION: The apparatus is equipped with a lens group 2 formed by arraying a plurality of lenses in one body and a dimming means 5 which is arranged in front of the lens group 2 to adjust the quantity of incident light, and the dimming means 5 adjusts the quantity of incident light by a dimming part 4 which interposes a dimming filter in front of the lens group 2 or puts it away. The dimming means 5 is further equipped with an optical shutter part 3. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lens device having a dimming unit and an optical shutter, which is suitable for devices such as a mobile phone, a PDA, and a thin digital camera having a built-in camera.
[0002]
[Prior art]
[Patent Document 1]
JP-A-5-16058 (pages 2-4, FIG. 2)
[0003]
Very small digital cameras and camera-equipped mobile phones often have no light control means such as an aperture, and sometimes do not have an optical shutter. The aperture is fixed and the shutter often uses an electronic shutter.
On the other hand, a photographing device such as a general camera or a video camera includes an aperture and a shutter. For example, an aperture must be provided inside the lens device as typically seen in the above-mentioned Patent Document 1. Sometimes, a shutter is also provided inside the lens device. The aperture device must be installed in the aperture space. The aperture space is a space on the optical path inside the lens, in which the amount of light can be adjusted without affecting the image formation.
FIG. 6 shows an example of a conventional lens device having a diaphragm. (A) shows a state where no aperture is added, and (b) shows a state where an aperture is added. The lens group 12 is divided into a first lens group 12a and a second lens group 12b at the position of the stop space. A stop device 14 is provided in the stop space, and a thin plate 14b having a hole is inserted by a motor 14a to provide a stop effect.
[0004]
[Problems to be solved by the invention]
However, such a lens device has a problem in terms of impact resistance and dust resistance when employed in a small photographing device such as a mobile phone with a built-in camera.
That is, the conventional lens device has a structure in which a diaphragm is provided between the lens groups, and the lens groups before and after the diaphragm are installed separately from each other. There was a disadvantage that it was easily displaced. Since the central axes of the lens groups need to match each other with very high accuracy, the conventional lens device can only withstand an impact dropped from a height of several tens of centimeters. However, when the lens device is used in a camera-equipped mobile phone or the like, it is necessary to have impact resistance enough to withstand a drop from a height of 1 meter or more, and this cannot be achieved with the conventional lens device structure.
Further, if there is a movable portion such as a diaphragm or a shutter between the lens groups, there is a problem that dust easily enters the lens device during these operations. An optical sensor used for a small camera such as a camera-equipped mobile phone is considerably smaller than that of a normal film camera, so that dust mixed in the lens device has a relatively large effect on a captured image.
In addition, when a shutter section is provided between the lens groups, it is structurally large and complicated, and it is difficult to reduce the size.
Due to these problems, conventionally, in a small-sized lens device, the provision of a diaphragm and an optical shutter has to be abandoned. Therefore, the incident light amount must be adjusted only by the shutter speed, and the shutter has to rely on an electronic shutter which is inferior to the optical shutter in image quality.
The present invention solves the above problems, and provides a lens device, a photographing device and a portable information device using the lens device, which are excellent in impact resistance and dust resistance, and can be provided with a dimming function and an optical shutter. With the goal.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problem, a lens device according to the present invention includes a lens group in which a plurality of lenses are arranged, and dimming means arranged on an incident side of the lens group to adjust the amount of incident light. A dimming device, comprising: a dimming filter, a frame that holds the dimming filter, and a motor that supports the frame and interposes or avoids the dimming filter in front of the lens group. And / or an optical shutter unit. Here, as an example of the frame, there is an example in which an opening is provided in a thin plate of metal, plastic, or the like, and a neutral density filter is held in the opening. There may be a plurality of frames, and in this case, a neutral density filter having a different neutral density for each frame can be used. The neutral density filter includes, for example, an ND filter. The optical shutter is a shutter that mechanically blocks incident light. For example, there is a shutter in which a plurality of blades are opened and closed on the entrance side of a lens group by a motor, and cover the entrance surface of the lens group in a closed state.
According to the present invention, there is also provided a photographing device using the above lens device. It is necessary for this photographing device to include an optical sensor unit that converts light emitted from the lens device into an electric signal.
Further, a portable information device provided with the above-described photographing device is also provided. Portable information devices include, for example, small computers such as mobile phones and PDAs.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of a lens device according to the present invention and a camera-equipped mobile phone using the same will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing one embodiment of a mobile phone according to the present invention using a lens device according to the present invention. FIG. 2 is a diagram showing a cross section taken along line CC shown in FIG. 3A and 3B are diagrams showing the operation of the optical shutter unit 3 shown in FIG. 2, wherein FIG. 3A shows an open state and FIG. 3B shows a closed state. 4A and 4B are diagrams showing the operation of the dimming unit 4 shown in FIG. 2. FIG. 4A shows a state without dimming, and FIG. 4B shows a state with dimming added. Each is shown.
[0007]
As shown in FIG. 1, an embodiment of a photographing apparatus according to the present invention and a lens apparatus used for the same are employed in a mobile phone unlike the prior art shown in FIG. One end is exposed on the outer surface A side of the main body 1 and a plurality of lenses are arranged in order, and a single focus type lens group 2 is interposed or avoided in front of the lens group 2 on the outer surface A side. Light adjusting means 5 (see FIG. 2) for adjusting the amount of light is provided. In the present embodiment, as shown in FIG. 2, the optical sensor unit 6 (CCD, CMOS) which is disposed on the inner surface B side in the main body 1 and receives light collected by the lens group 2 and converts the light into image information. Etc.).
[0008]
The lens group 2 is formed integrally from the entrance side to the exit side without having a divided portion. There is no aperture section or optical shutter that exists in such a manner as to separate the lens groups as in the related art. Such a structure is excellent in impact resistance and dust resistance, and also facilitates alignment of lenses, reduces the number of parts, and can reduce costs.
[0009]
As shown in FIG. 2, the dimming unit 5 is disposed on the incident side of the lens group 2, and includes a dimming unit 4 that reduces the amount of light incident on the lens group by a dimming filter 4c (see FIG. 4). And an optical shutter unit 3 for blocking light. As shown in FIG. 4 (a), the dimming unit 4 mounts a thin plate 4b on the motor 4a, opens a hole in the plate 4b, and attaches a dimming filter 4c to the hole of the plate 4b. I have. As shown in FIG. 3, the optical shutter unit 3 mounts two thin plate-shaped blocking plates 3b to the motor 3a, and supports the blocking plates 3b so as to open and close with each other. By adopting such a structure, although it does not have the function of adjusting the depth of field that the normal "aperture" has, it realizes the function of adjusting the amount of incident light while improving impact resistance and dust resistance. Can be. Accordingly, it is not necessary to provide a mechanism for dividing the lens group 2, so that impact resistance and dust resistance can be improved, and high-quality photographing can be performed as compared with the electronic shutter.
[0010]
The dimming unit 5 including the dimming unit 4 and the optical shutter unit 3 is also formed integrally with the lens group 2 shown in FIG. 2 so that the number of parts can be further reduced, and the manufacturing efficiency in the assembly process is increased. Can be further improved.
[0011]
As shown in FIG. 3A, an embodiment of the lens device according to the present invention and the camera-equipped mobile phone using the lens device according to the present invention, as shown in FIG. Is driven, the blocking plate 3b is arranged in an open state to enable photographing of an object. On the other hand, when the main body 1 is not used, the motor 3a is driven again to close the light blocking plate 3b as shown in FIG. Reset the image information. Thus, the optical sensor unit 6 prevents unnecessary light that enters through the lens group 2 when not in use from adversely affecting the converted data.
[0012]
Further, at the time of photographing an object, the motor 4a is driven or not driven in accordance with the light information of the amount of incident light detected by the optical sensor unit 6, so that the light reducing unit 4 is interposed or avoided in front of the lens group 2 to enter. Adjust the light intensity. At this time, the plate 4b is normally avoided at a position not interposed in front of the lens group 2 shown in FIG. 4A, and the motor 4a is in a non-driven state to enable photographing in a dark place.
[0013]
On the other hand, at the time of photographing in a bright place, as shown in FIG. 4B, the motor 4a is driven in accordance with the light information of the state where the amount of incident light detected by the optical sensor unit 6 is large, and the light-reducing filter 4c of the plate 4b Is lowered and interposed in front of the lens group 2 to adjust the amount of incident light. The neutral density filter 4c adjusts the amount of light under a condition where light is too strong, such as under direct sunlight, and plays a role of “weakening light”. Therefore, the neutral density filter 4c has an effect of reducing the problem that the image element such as the optical sensor unit 6 is saturated when the image is captured under extremely intense light, and the image becomes whiter.
[0014]
As described above, the embodiments of the photographing apparatus according to the present invention and the lens apparatus used therein have been described in detail. However, the present invention is not limited to the above-described embodiments, and can be changed without departing from the gist thereof. is there. For example, the lens device according to the present invention can be employed in devices such as a digital camera, a film camera, and a video camera (camcorder). Further, the embodiment in which the lens group is formed as a single focus system has been described. However, the present invention is not limited to this. For example, the present invention can be applied to a lens group other than a single focus system having a zoom function.
[0015]
【The invention's effect】
As described above, according to the present invention, the dimming function and the installation of the optical shutter are realized while improving the shock resistance and the dust resistance, and the high-quality photographing by the optical shutter is enabled. Further, the assembly is easy and the number of parts is reduced. There is provided a lens device capable of performing the following. The lens device according to the present invention having such features is most suitable for a camera-equipped mobile phone and a small digital camera that require high impact resistance and dust resistance.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment in which a lens device according to the present invention is employed in a mobile phone.
FIG. 2 is a view showing a cross section taken along the line CC shown in FIG. 1;
FIG. 3 is a view showing the operation of a shutter unit shown in FIG. 2;
FIG. 4 is a diagram showing the operation of the dimming unit shown in FIG.
FIG. 5 is a diagram showing an embodiment of a conventional photographing apparatus.
FIG. 6 is a view showing the operation of the photographing apparatus shown in FIG. 5;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body 2 Lens group 2a 1st lens group 2b 2nd lens group 3 Optical shutter part 3a Motor 3b Cutoff plate 4 Light reduction part 4a Motor 4b Plate 4c Light reduction filter 5 Light control means 6 Optical sensor part

Claims (3)

A lens group in which a plurality of lenses are arranged,
Dimming means arranged on the incident side of the lens group to adjust the amount of incident light,
The dimming unit includes a dimming filter, a frame that holds the dimming filter, and a motor that supports the frame and interposes or avoids the dimming filter in front of the lens group. And a lens device provided with one or both of an optical shutter unit. An imaging apparatus comprising: the lens device according to claim 1; and an optical sensor unit that converts light emitted from the lens device into an electric signal. A portable information device comprising the imaging device according to claim 2.

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