초록 ▼

A stereoscopic image of an object is focused on an image pickup device based on the degree to which left and right images of the object are coincident on the image pickup device. Signals produced by the image pickup device that represent the left and right images are compared with each other to deve

A stereoscopic image of an object is focused on an image pickup device based on the degree to which left and right images of the object are coincident on the image pickup device. Signals produced by the image pickup device that represent the left and right images are compared with each other to develop a control signal that indicates the coincidence of the left and right images on the image pickup device, and the spacing between the image pickup device and an optical element that directs the images onto the device is changed in response to the control signal to increase the coincidence. Two alternative types of comparison are performed, each of which indicates the degree of coincidence (and hence the quality of focus) of the left and right images on the image detector. In one approach, the left and right images are compared to determine their cross correlation on the image pickup device, and the spacing is changed to maximize the correlation. Alternatively, the comparison determines the difference between the left and right images on the image pickup device, and the spacing is changed to minimize the difference. The focusing technique is useful in, e.g., the optical system of an endoscope. Rangefinding and videometry are also performed to determine the distance to the object being viewed, as well as its position and size.

대표청구항 ▼

[ What is claimed is:] [1.] A method for focusing a stereoscopic image of an object on an image pickup device, comprisingusing an optical element axially spaced from said image pickup device to apply a left image and a right image of the object to said image pickup device so that said image pickup d

[ What is claimed is:] [1.] A method for focusing a stereoscopic image of an object on an image pickup device, comprisingusing an optical element axially spaced from said image pickup device to apply a left image and a right image of the object to said image pickup device so that said image pickup device produces signals representative of said left image and signals representative of said right image, said optical element and said image pickup device being arranged such that changing the axial spacing between said optical element and said image pickup device produces relative displacement between said left image and said right image on said image pickup device,comparing said signals representative of said left image with said signals representative of said right image to determine a coincidence between said left image and said right image on said image pickup device, andchanging the axial spacing between said optical element and said image pickup device to produce relative displacement of said left image and said right image on said image pickup device to increase the coincidence between said left image and said right image on said image pickup device, and thereby increase the focusing of said left image and said right image on said image pickup device.