New TechnologyJapan@August,2001
Vstone Co.,Ltd. has developed a free curvature mirror camera Visual Stone, ND Series, that does not generate any distortion in the image peripheral parts even when the images are photographed in wide angle. By analyzing and designing the mirror with a newly developed free curvature design technology, it is possible to perform photography as if the ground and wall were seen directly from above. Normally, when a camera image angle (horizontal) is widened, the target object of photography is photographed in warped from (barrel from), but with the newly developed free curvature mirror camera, there is no need for corrective image treatment.
With the conventional type of camera, the target space of photography will be determined by the lens. However, the materials comprising the lens will be restricted by factors such as the transparency or the index of refraction and there is also the problem of the occurrence of color aberration. Due to these reasons, with ordinary cameras, multiple lens are employed to comprise a lens assembly and to cope whit the situation.
With a wide angle camera, a larger number of lens will have to be employed, which will increase the cost, and there is also the problem that the lens assembly cannot be made distortion-free. The method for the reflection mirror eliminates all these unique problems associated with the lens.
With this free curvature mirror camera, a mirror with a unique shape is used in combination with an ordinary type of camera to widen the photographic angle, and by which it will become possible to photograph images free of the negative distortion (barrel type deformation) that is normally generated with images photographed with a wide angle camera. The free curvature mirror camera is so computed and designed that the information relating to a point in space corresponds with a prescribed spot within an image obtained with a product, its mirror is computed and designed continuously so that the plane intersecting perpendicular to the camera optical axis is displayed in the same geometrical ratio on the frame. As a result, while the camera horizontal image angle is as wide as about 140 degrees, the image will appear as if it was photographed directly from above, and will be free of any distortion. The photographic range is 7.5m longitudinally x 10m laterally, the image angle about 132 degrees horizontally, and the sector of crime prevention.
Vstone Co., Ltd.
4-2-7,shimaya, Konohana-ku,Osaka 554-0024
Tel: +81-6-6467-6601
Fax: +81-6-6467-6602