Patent ID: 8130309
Filing Date: 2012-03-06
Classification: G01S

Abstract:
1. A light spot position detection device comprising: a light emitting element, a condensing lens for condensing a pencil of light emitted from the light emitting element or a pencil of light resulting from reflection of the pencil of light by an object; a solid-state image sensor on which a light spot is formed by the pencil of light or pencil of reflected light condensed by the condensing lens, a pixel section that is provided in the solid-state image sensor and that includes pixels for detecting the light spot and performing conversion into pixel data corresponding to a quantity of received light, a digital converting unit for converting the pixel data of the pixels in the pixel section into digital values, a memory unit for storing the pixel data, converted into the digital values by the digital converting unit, into storage portions corresponding to the respective pixels of the pixel section, a processor unit for computing a position of the light spot on the pixel section on basis of the digital pixel data stored in the memory unit, and a control unit for controlling the light emitting element, the solid-state image sensor, the memory unit, and the processor unit, and thereby detecting the position of the light spot formed on the solid-state image sensor, wherein a frame of operation to be performed by the control unit includes: the control unit controls the light emitting element, the solid-state image sensor and the memory unit so as to repetitively perform a given number of the frames of operation to accumulate the pixel data of only the signal light in the storage portions in the memory unit, the control unit controls the processor unit so that the processor unit calculates the position of the light spot on the pixel section on basis of the pixel data of only the signal light accumulated and stored in the storage portions in the memory unit, and the control unit thereby derives output of positional information on the light spot for the given number of frames whether the storage portions in the memory unit are saturated or not with the pixel data.