JPH05130470A - Lens conversion adaptor mechanism for video camera - Google Patents

Abstract

PURPOSE:To take a required maximum field angle by forming a large cylinder side end in an inner side of a small cylinder to be a conical face so as to attain stable mount of the conversion adaptor. CONSTITUTION:An end of a front side at an inner circumferential face of a front cylinder 7 is formed to be a conical face 42 in which an optical path space 43 is gradually increased toward the front side. Then a padding part 46 whose outer diameter is gradually increased toward a large cylinder 40b is provided to an end of the large cylinder 40b at the outer side of a small cylinder 40a, and an end of the large cylinder 40b at the inner face of the small cylinder 40a is formed to be a conical face 47 to increase the optical space 43 gradually toward the large cylinder 40b. Thus, even when the length of the small cylinder 40a of the conversion adaptor 40 is set to be similar to that of a conventional mechanism, a maximum field angle is increased. Thus, the conversion adaptor 40 is stably mounted and the required maximum field angle is taken.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-panel video camera.

[0002]

Video cameras can be classified as broadcast, consumer, and industrial. In the fields of consumer use and industrial use, it is desired to reduce the size of the video camera as much as possible in order to expand the range of application by downsizing the video camera and the size of the device used. Then, the applicant has developed a small video camera in response to this demand. In this video camera, since the diameter of the front barrel itself as well as the solid-state image sensor is reduced, the conventional lens barrel cannot be mounted directly, but only through the conversion adapter.

Here, it is conceivable to configure the conversion adapter 40 as shown in FIG. That is, the small tube portion 40a, the large tube portion 40b, and the connecting portion 40c that connects them are formed, and the optical path space 43 is formed inside them. A screw portion 44 is provided on the outer peripheral surface of the small tubular portion 40a, and the screw portion 44 is screwed into the screw portion 41 on the inner peripheral surface of the front tubular body 7 of the video camera BK. In the front cylindrical body 7, the image frame plate 13 and the optical filter 1 are arranged in order from the front side.
4, the buffer member 15, the solid-state image sensor 16, and the back plate 17 are arranged, and these are fixed by the adjusting ring member 18. The threaded portion 4 is also provided on the inner peripheral surface of the large tubular portion 40b.
5 is provided, and the diameter of the screw portion 45 is formed to be the same as that of the conventional front cylindrical body. A conventional lens barrel (not shown) is attached to the screw portion 45.

[0004]

However, according to the above configuration, there is a drawback that vignetting of the optical path occurs because the maximum angle of view smaller than the required maximum angle of view can be obtained as shown in FIG. It was Here, if the length of the front cylindrical body 7 is configured to be short, the maximum angle of view can be increased, but since the insertion amount of the small cylindrical portion 40a of the conversion adapter 40 is reduced, the conversion adapter 40 can be mounted stably. It cannot be adopted because it cannot be done.

Therefore, it is an object of the present invention to provide a lens conversion adapter mechanism of a video camera which can stably mount the conversion adapter and can obtain a required maximum angle of view.

[0006]

A lens conversion adapter mechanism of a video camera according to the present invention for achieving the above-mentioned object has a conversion adapter mounted on a front cylinder, and the lens cylinder is mounted through this conversion adapter. In the lens conversion adapter mechanism of the video camera, the conversion adapter is configured as an inner peripheral surface of the front cylindrical body, and an end portion on the front side is configured as a conical surface that gradually increases the optical path space as it approaches the front side. The small cylinder portion, a large cylinder portion having the same axis as the center thereof, and a connecting portion for connecting them are provided, and a screw portion screwed to the front cylinder body is provided on an outer peripheral surface of the small cylinder portion. A threaded portion for screw-engaging the lens barrel is provided on the inner peripheral surface of the outer peripheral surface of the small tubular portion, and the outer diameter is gradually increased toward the large tubular portion at the end portion on the large tubular portion side. Overlaid portion on the inner surface of the small tube portion provided with a to and is obtained by gradually constructed as conical surfaces to increase the optical path space as it approaches the end of the large-cylinder-side to the large-cylinder side.

[0007]

A large maximum angle of view can be obtained because the end of the inner surface of the small tube portion on the side of the large tube is a conical surface without shortening the length of the small tube portion of the conversion adapter.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show one embodiment of the present invention, in which a video camera is equipped with a conversion adapter 40, and a conventional large-diameter lens barrel (not shown) is mounted through the conversion adapter 40. .. First, the configuration of the video camera will be described with reference to FIGS. 2 to 5, and then the lens conversion adapter mechanism will be described with reference to FIG.

FIG. 2 is an exploded perspective view of the video camera, and FIG.
4 is a perspective view of the video camera, FIG. 4 is a vertical sectional view of the video camera, and FIG. 5 is a horizontal sectional view of the video camera.

2 to 5, the video camera includes a case body A, a front block body B and a substrate block body C.
And the rear block body D are assembled.

The case body A is made of a material having a good thermal conductivity, and has a slender tubular shape whose cross-sectional outer shape is an octagon. This octagon is not a regular octagon, but it is constructed point-symmetrically with respect to the center point. Specifically, it is based on a regular quadrangle, and is formed by forming inclined surfaces 2 notched at 45 degrees at the four corners of the four surfaces 1. Several grooves 3 are formed in the longitudinal direction on the four surfaces 1 so that the total surface area is large, and positioning grooves 4 are formed on the four surfaces 1, respectively. An adjusting hole 5 is formed on one of the four surfaces 1 (upper surface). Further, each of the four inclined surfaces 2 has a screw insertion hole 6 formed at the front end thereof, and the screw insertion hole 6 is also formed at the opposite two surfaces of the rear end thereof.

The front block body B is inserted into the front side of the case body A, and the front cylinder body 7 substantially covers the outside. The front cylinder 7 includes a front portion 8 and a mounting portion 9.
And the cylindrical portion 10 are integrally provided, and an optical path space 11 for entering light is formed in the whole of them.

The front portion 8 is arranged on the front surface of the case body A, and the lens mounting reference surface 8a is provided on the front surface of the front portion 8.
Is configured. The mounting portion 9 has an octagonal shape corresponding to the inner surface dimension of the case body A and is inserted into the case body A. Then, screw holes 9a are formed in the four inclined surfaces, and the screws 12 inserted into the screw insertion holes 6 of the case body A are screwed into the screw holes 9a so that the front cylinder 7 is attached to the case body A. It has been concluded.

Notched grooves 10a are formed in the cylindrical portion 10 at four locations, and each notched groove 10a is open at the rear end. An image frame plate 13, an optical filter 14, a buffer member 15, and a solid-state image sensor 16 are sequentially inserted into the cylindrical portion 10 from the front. A threaded portion 10b is formed on the outer periphery of the tubular portion 10, and an adjustment ring member 18 described below is screwed into the threaded portion 10b. A positioning protrusion 10c is provided at the rear end of the tubular portion 10.

The image frame plate 13 has a substantially disk shape having the same size as the inner diameter of the cylindrical portion 10 and has a rectangular opening 13a. The aspect ratio of the opening 13a is set to be the same as that of the imaging surface 16a of the solid-state imaging device 16 described below.
Protrusions 13b are integrally provided on the outer periphery of the image frame plate 13 and at four corners of the opening 13a. The picture frame plate 13 is positioned so that the four protrusions 13 b project into the respective cutout grooves 10 a of the cylindrical portion 10.

The optical filter 14 has a rectangular shape and is constituted by laminating a low pass filter, an infrared cut filter and the like. The four corners of the optical filter 14 have the cylindrical portion 1
It is positioned so as to project into each of the notch grooves 10a.

The buffer member 15 is made of an elastic material and has a substantially ring shape. The front surface of the buffer member 15 is brought into contact with the outer peripheral edge of the optical filter 14 to restrict forward displacement, and the rear surface thereof is brought into contact with the outer peripheral edge of the solid-state image pickup element 16 so that the buffer member 15 is unique. The vibration applied to the solid-state image sensor 16 is buffered.

The solid-state image pickup device 16 has an image pickup surface 16a at the center, and its rear surface is positioned and fixed to the back plate 17.

The back plate 17 has a substantially disc shape having a size slightly larger than the inner diameter of the tubular portion 10, and the front surface thereof has a guide ring portion 17 having the same diameter as the inner diameter of the tubular portion 10.
a is provided. And this guide ring portion 17
A part of a is inserted into the cylindrical portion 10. Further, a positioning groove 17b is formed in the upper portion of the back plate 17, and the positioning protrusion 10c of the front cylindrical body 7 is arranged in the positioning groove 17b so that the back plate 17 is restricted in its rotational position.

The adjusting ring member 18 has a threaded portion 1 on its inner circumference.
8a is formed, and the screw portion 18a is formed on the cylindrical portion 1a.
It is screwed into the 0 screw part 10b. Adjustment ring member 1
A pressing portion 18b extending in the central direction is provided at the rear end of 8, and the pressing portion 18b presses the rear surface of the back plate 17. That is, the adjustment ring member 18 is provided on the solid-state image pickup device 16 via the back plate 17 so that
Pressing to 5.

The substrate block C includes an inner case 20 and three substrates 21 housed in the inner case 20.
And etc. Two flexible substrates 22 are connected between the three substrates 21 arranged in a straight line, and the three substrates 21 thus integrated are arranged in a zigzag manner. Electronic components 23 are mounted on both surfaces of the three substrates 21, and a drive circuit for a video signal is configured by the three substrates 21.
A plate-shaped silicon rubber 34 is interposed between the adjacent substrates 21, and the upper surface of the electronic component 23 is in contact with the silicon rubber 34.

The inner case 20 is made of a member having conductivity and spring property and having a good heat transfer coefficient, and is composed of an upper case member 20a and a lower case member 20b. The upper case member 20a has a substantially U-shape, and the lower case 20b has a flat plate shape. The upper case member 20a and the lower case member 20b cover three substrates 21 substantially entirely. The upper surface of the upper case member 20a and the lower case member 20
Substrate supporting slits 24 are formed on the lower surface of b, and the corners of each substrate 21 are inserted into the respective substrate supporting slits 24. Screw insertion holes 25 are formed in the upper surface of the upper case member 20a and the lower surface of the lower case member 20b, and the screws 26 inserted in the respective screw insertion holes 24 are screwed into the screw holes 33 of the rear panel 29 described below. .. The tip side of each screw 26 is bent inside flexible substrate 2
It is inserted in the space formed by 2, and each of the screws 26 also positions the substrate 21. That is, the inner case 20 accommodates the three substrates 21 with the substrate supporting slit 24 and the screw 26 held at a constant interval.

Further, the upper case member 20a and the lower case member 20b have a tongue-shaped component pressure contact piece 27 protruding inward.
Are provided at several places, and the component pressure contact pieces 27 are in pressure contact with the electronic component 23, which generates a large amount of heat, by its leaf spring force.
On the contrary, the upper case member 20a and the lower case member 20b
The tongue-shaped case pressure contact pieces 28 protruding outward are provided at several places on all four surfaces of the case pressure contact pieces 2
8 mo It is pressed against the four inner surfaces of the case body A by its leaf spring force. Therefore, the substrate block body C is housed in the case body A with a small gap and receiving the leaf spring force of the case pressure contact piece 28.

The rear block body D has a rear panel 29, and screw holes 30 are formed in the rear panel 29. The screw 31 inserted into the screw insertion hole 6 of the case body A is screwed into the screw hole 30 so that the rear block body D is attached to the rear end side of the case body A. Rear panel 29
Is extended inside the case body A, and a screw hole 3 is provided at the extended end.
Two are provided. The screw 26 inserted into the screw insertion hole 25 of the inner case 20 as described above is screwed into the screw hole 32, whereby the rear block body D and the substrate block body C are connected.

A connector 33 is fixed to the rear panel 29, and a video signal of the drive circuit is output from this connector 33.

FIG. 1 shows a sectional view of the lens conversion adapter mechanism. In FIG. 1, a screw portion 41 is provided on the front side of the inner peripheral surface of the front cylindrical body 7 which constitutes the optical path space 11.
Is provided, and a dedicated lens barrel (not shown) and the conversion adapter 40 described below are selectively mounted by the screw portion 41. In this embodiment, the conversion adapter 40 is attached. Further, the inner peripheral surface of the front cylindrical body 7 and the end portion on the front side are configured as a conical surface 42 that gradually increases the optical path space 11 as it approaches the front side.

The conversion adapter 40 comprises a small tubular portion 40a, a large tubular portion 40b having the same axis as the center thereof, and a connecting portion 40c for connecting them, and an optical path space 43 is formed on the inner periphery thereof. The screw portion 4 is provided on the outer peripheral surface of the small tubular portion 40a.
4 is provided, and the screw portion 44 is screwed into the screw portion 41 of the front cylindrical body 7. A threaded portion 45 is also provided on the inner peripheral surface of the large tubular portion 40b, and the diameter of the threaded portion 45 is formed to be the same as that of a conventional video camera. Then, a conventional lens barrel (not shown) is attached to the screw portion 45.

A built-up portion 46 is integrally provided on the outer surface of the small tubular portion 40a and at the end portion on the large tubular portion 40b side so that the outer shape gradually increases toward the large tubular portion 40b side. The built-up portion 46 is arranged close to the conical surface 42 of the front cylindrical body 7. In addition, the small tube portion 40
The inner surface of a and the end on the large tube portion 40b side is configured as a conical surface 47 that gradually increases the optical path space 43 as it approaches the large tube portion 40b side. The wall thickness d of the conical surface 47 has a certain thickness or more due to the built-up portion 46, so that there is no problem in strength.

In the above construction, even if the insertion length L of the small tube portion 40a of the conversion adapter 40 is the same as the conventional one, the maximum angle of view becomes large due to the conical surface 47 on the inner surface of the small tube portion 40a as shown in FIG. You can take the maximum angle of view.

[0030]

As described above, according to the present invention, the end portion of the outer peripheral surface of the front cylindrical body is formed as a conical surface, and the built-up portion is provided at the insertion end portion of the outer peripheral surface of the small cylindrical portion of the conversion adapter. Since the insertion end of the inner peripheral surface of the small cylinder is configured as a conical surface,
Even if the length of the small tube of the conversion adapter is set to the same length as the conventional one, the maximum angle of view becomes large, so the conversion adapter can be mounted stably and the required maximum angle of view can be obtained. It has the effect of being able to.

Further, since the wall thickness of the conical surface portion of the small tubular portion has a certain thickness or more depending on the built-up portion, there is an effect that there is no problem in strength.

[Brief description of drawings]

FIG. 1 is a cross-sectional view (example) of a lens conversion adapter mechanism.

FIG. 2 is an exploded perspective view of a video camera (example).

FIG. 3 is a perspective view of a video camera (example).

FIG. 4 is a vertical sectional view of a video camera (example).

FIG. 5 is a cross-sectional view of the video camera (example).

FIG. 6 is a sectional view of a lens conversion adapter mechanism.

[Explanation of symbols]

7 ... Front cylinder, 40 ... Conversion adapter, 40a ... Small cylinder part, 40b ... Large cylinder part, 40c ... Connection part, 42, 47 ... Conical surface, 43 ... Optical path space, 44, 45 ... Screw part, 46 ... Overlay Department.

Claims (1)

[Claims] 1. A conversion adapter is attached to a front cylinder,
In a lens conversion adapter mechanism for a video camera in which a lens barrel is mounted via this conversion adapter, the optical path space is gradually increased on the inner peripheral surface of the front barrel and as the front end approaches the front side. The conversion adapter is composed of a small tubular portion, a large tubular portion centered on the same with the small tubular portion, and a connecting portion connecting these, and the front tubular body is provided on the outer peripheral surface of the small tubular portion. A screw part for screwing is provided, a screw part for screwing the lens barrel is provided on an inner peripheral surface of the large cylinder part, and the large cylinder is provided on an outer surface of the small cylinder part and at an end portion on the large cylinder part side. A build-up portion that gradually increases the outer diameter as it approaches the portion side, and the optical path space is gradually increased on the inner surface of the small tubular portion and at the end of the large tubular portion toward the large tubular portion. As a conical surface Camcorder lens adapter mechanism, characterized in that form have.