JPH11205664A - Image pickup device and video camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device, with which more miniaturization is possible, and a video camera using this device. SOLUTION: Behind a single ball lens 1, an isosceles triangular pole prism reflection mirror 4 having an apex angle θ, which is a right angle or obtuse angle, is arranged while turning one isosceles part 4a toward the single ball lens 1, and an infrared (IR) cut filter 2 and an imaging device 3 in fare chip state are successively arranged in a direction opposed to another isosceles part 4b. Thus a depth dimension D from the single ball lens 1 to the imaging device 3 is shortened and the image pickup device and the video camera loading this device can be more miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus using a solid-state image pickup device such as a CCD or a MOS, and a video camera using the same, particularly a thin type which is built in or attached to a liquid crystal display section of a handheld personal computer or the like. Related to video cameras.

[0002]

2. Description of the Related Art Conventionally, a video camera of this type has been disclosed in the Journal of the Institute of Image Information and Television Engineers, vol. 51, No. 2, pp. 241-247 (19)
97) is known. FIG. 3 shows the configuration of an optical system of an imaging device used in a conventional thin video camera. In FIG. 3, 1 is a single lens and 2 is IR
An (infrared) cut filter 3 is a bare chip image sensor such as a CCD or a MOS having a color filter disposed on the front surface.

Next, the operation of the above conventional example will be described. The luminous flux emitted from the subject is imaged on the imaging surface of the image sensor 3 by the single lens 1, but before that, the IR sensitivity is invalidated by the IR cut filter 2 to ensure color reproduction. An image signal in pixel units output from the solid-state imaging device 3 is subjected to noise suppression,
After correcting the image defect, a luminance signal is extracted, and color separation is performed to obtain a video signal including the luminance signal and the chroma signal.

[0004]

However, in the above-described conventional imaging apparatus, since the single lens 1 and the image sensor 3 are arranged in a line, the two must be separated by the focal length of the single lens 1. However, the depth dimension D from the single lens 1 to the image pickup device 3 becomes longer, and there is a limit to miniaturization of the apparatus.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide an imaging device which can be further downsized and a video camera using the same.

[0006]

According to the present invention, in order to achieve the above object, an isosceles triangular prism reflector having a right angle or an obtuse angle is disposed behind a single lens to direct an image-forming ray to the side. The image is formed on an image sensor arranged in that direction, thereby reducing the depth dimension of the image capturing apparatus and further reducing the size of the image capturing apparatus and the video camera equipped with the same. it can.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is characterized in that an isosceles triangular prism reflecting mirror whose apex angle is a right angle is provided behind a single lens at one of its isosceles portions on the single lens side. And an infrared cut filter and an image sensor in a bare chip state are sequentially arranged in a direction facing the other isosceles part of the prism reflecting mirror. This has the effect that the depth dimension can be shortened to further reduce the size of the imaging device.

The invention according to claim 2 of the present invention is characterized in that an isosceles triangular prism prism reflecting mirror having an obtuse angle is used instead of an isosceles triangular prism reflecting mirror having a right apex angle. The imaging device according to claim 1, wherein not only an isosceles triangular prism prism having a right apex angle but also an isosceles triangular prism prism having an obtuse apex angle can be used.

According to a third aspect of the present invention, there is provided the imaging apparatus according to the second aspect, wherein an ineffective portion at a bottom angle of the reflecting prism on the image sensor side is cut off.
This has the effect that the depth dimension of the imaging device can be further shortened and the size of the imaging device can be further reduced.

According to a fourth aspect of the present invention, in the imaging apparatus according to the third aspect, the apex angle of the reflection prism is set to 100 ° ± 5 °. There is an effect that the image pickup device can be further miniaturized by minimizing the length.

According to a fifth aspect of the present invention, there is provided a video camera using the imaging device according to any one of the first to fourth aspects, wherein the depth dimension of the imaging device is reduced. This has the effect that the size of the video camera can be further reduced.

(Embodiment 1) FIG. 1 shows a configuration of an image pickup apparatus according to a first embodiment of the present invention. The same members as those of the conventional image pickup apparatus shown in FIG. It is. In FIG. 1, reference numeral 1 denotes a single lens for forming an image of light from a subject, and a plastic lens or a glass lens having an aspheric surface on both sides is used. Reference numeral 2 denotes an IR cut filter that cuts infrared rays that cannot be seen by human eyes, and reference numeral 3 denotes a bare chip image sensor such as a CCD or a MOS having a color filter disposed on the front surface. 4 is a single lens 1
Is a right-angled isosceles triangular prism reflecting mirror having a vertical angle θ of a right angle, one of which is an isosceles portion 4a facing the single lens 1 and is arranged at a right angle to the optical axis 0L. At the same time, the other isosceles portion 4 b is arranged so as to face the IR cut filter 2 and the image sensor 3. As a result, the optical axis 0L of the single lens 1 is compared with the optical axis 0L of the image sensor 3.
C intersect at an angle of 90 °. As the prism reflecting mirror 4, a plastic prism or a glass prism provided with a vapor deposition film having a total reflection characteristic on the bottom 4c is used.

The operation of the imaging apparatus configured as described above will be described with reference to FIG. The light beam L1 emitted from the subject and parallel to the optical axis 0 is refracted by the single lens 1, becomes an image forming light beam, and enters one of the isosceles 4a of the prism reflecting mirror 4. Bottom part 4c of prism reflecting mirror 4
Is arranged at 45 ° to the optical axis 0L, the incident light beam is reflected here in the direction of 45 °, exits from the other isosceles portion 4b, passes through the IR cut filter 2, and passes through the IR cut filter 2. An image is formed at the center of the light receiving surface. The light beam L2 that is not parallel to the optical axis 0L is similarly reflected by the prism reflecting mirror 4 and forms an image on the end of the image sensor 3. The image sensor 3 sequentially photoelectrically converts the incident light from one end to the other end, and outputs a signal for each pixel. The image processing circuit performs noise suppression and image defect correction in an image processing circuit, extracts a luminance signal, and performs color separation to obtain a video signal including a luminance signal and a chroma signal.

As described above, according to the first embodiment, the isosceles triangular prism prism reflecting mirror 4 having the right apex angle θ is arranged with the one isosceles portion 4a facing the single lens 1. Since the IR cut filter 2 and the image sensor 3 in a bare chip state are sequentially arranged in the direction facing the other isosceles portion 4b of the prism reflecting mirror 4, the depth dimension D from the single lens 1 to the image sensor 3 is conventionally reduced. And the size of the imaging device can be reduced. Incidentally, the depth dimension D of the conventional imaging apparatus shown in FIG.
mm (for a 1/4 inch size), the depth dimension D can be set to 5.4 mm (for a 1/4 inch size) in the first embodiment.

(Embodiment 2) FIG. 2 shows a configuration of an optical system of an image pickup apparatus according to a second embodiment of the present invention. In FIG. 2, 1 is a single lens, 2 is an IR cut filter, and 3 is an image sensor, which are the same as those shown in FIG. Numeral 5 is an obtuse angled isosceles triangular prism reflecting mirror having an apex angle θ of an obtuse angle, preferably 100 ° ± 5 °. And the other isosceles portion 4b is arranged toward the IR cut filter 2 and the image sensor 3 with the optical axis 0L slightly inclined inward. As a result, the optical axis 0C of the imaging element 3 intersects the optical axis 0L of the single lens 1 at an angle smaller than 90 °. As the prism reflecting mirror 5, a plastic prism or a glass prism provided with a vapor deposition film having a total reflection characteristic on the bottom 5c is used, and an ineffective portion 5d at the bottom angle on the imaging element 3 side is cut off to form a single lens. The depth dimension D from 1 to the image sensor 3 is further reduced. The operation of the second embodiment is the same as that of the first embodiment.
A duplicate description will be omitted.

As described above, according to the second embodiment, the isosceles triangular prism prism reflecting mirror 5 having the obtuse angle θ is an obtuse angle, and one of the isosceles 5a is slightly inclined inward with respect to the single lens 1. In addition, the IR cut filter 2 and the image sensor 3 in a bare chip state are sequentially arranged in a direction facing the other isosceles portion 5b of the prism reflector 5, and the prism reflector 5 has a base angle at the base angle on the image sensor 3 side. Since the ineffective portion has been removed, the depth dimension D from the single lens 1 to the imaging element 3 can be made shorter than in the first embodiment, and the imaging apparatus can be further downsized. By the way,
In the first embodiment, the depth dimension D can be 4.6 mm.

(Embodiment 3) Embodiment 3 is an application of the imaging device described in Embodiments 1 and 2 above as an imaging device for a video camera.
It can be applied not only to a video camera built in or attached to a liquid crystal display unit of a personal computer or the like, but also to a video camera built in or attached to a liquid crystal display unit of a thinner handheld personal computer or the like. An ultra-thin video camera can be realized.

[0018]

According to the present invention, as is apparent from the above embodiment, a right angle or obtuse angled isosceles triangular prism reflecting mirror is arranged behind a single lens and the imaging light is directed sideways. Since the image is formed on the image pickup device arranged in the direction, the depth dimension of the image pickup device can be shortened, and the image pickup device and the video camera equipped with the image pickup device can be further downsized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an optical system of an imaging device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an optical system of an imaging device according to a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of an optical system of an imaging device in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Single lens 2 IR cut filter 3 Image sensor 4 Right angle isosceles triangular prism prism reflecting mirror 5 Obtuse isosceles triangular prism prism reflecting mirror 0L Optical axis of single lens 0C Optical axis of image sensor D Depth dimension θ Apex angle

Claims (5)

[Claims] 1. An isosceles triangular prism reflecting mirror having a right-angled apex angle is disposed behind a single lens with one isosceles portion facing the single lens, and the other of the prism reflecting mirror is disposed. An imaging apparatus comprising: an infrared cut filter and an imaging element in a bare chip state sequentially arranged in a direction facing an isosceles part. 2. The image pickup apparatus according to claim 1, wherein an isosceles triangular prism prism having an obtuse angle is used instead of an isosceles triangular prism prism having a right apex angle. 3. The imaging apparatus according to claim 2, wherein an ineffective portion at a base angle of the reflection prism on the imaging element side is cut off. 4. The vertical angle of the reflecting prism is set to 100 ° ± 5.
4. The imaging device according to claim 3, wherein the angle is set to degrees. 5. A video camera using the imaging device according to claim 1.