Patent ID: 7436495

Claim:
A range image producing apparatus comprising: a light emitting element for irradiating a pulse light toward a predetermined measurement range; an imaging device including a plurality of unit sensors, which are arranged in a two-dimensional plane, wherein each unit sensor includes a charge storage type photo electric conversion element for receiving a reflected pulse light reflected by an object and for converting the reflected pulse light to an electric charge, a first storage element for accumulating au output of the photo electric conversion element as a first pixel data and a second storage element for accumulating the output of the photo electric conversion element as a second pixel data; a controller, wherein the controller initializes the first and second storage elements to be a predetermined initial voltage, respectively, wherein the controller controls the light emitting element in such a manner that the light emitting element irradiates the pulse light during a first time period, which is a time for the pulse light to travel back and forth to a predetermined maximum measurement distance, wherein the controller controls the first storage element in such a manner that the first storage element accumulates the output of the photo electric conversion element during the first time period, and wherein the controller controls the second storage element in such a manner that the second storage element accumulates the output of the photo electric conversion element during a second time period, which starts at an end of the first time period and is equal to or longer than the first time period; and a range data producing element for producing a range data, which represents a distance between the object and the apparatus, wherein the range data is produced based on a ratio between the first pixel data and a total pixel data or a ratio between the second pixel data and the total pixel data, wherein the total pixel data is a sum of the first pixel data and the second pixel data, wherein the range data producing element produces a range image having a pixel data of the range data, wherein the range data producing element produces the range image in such a manner that the range image is obtained by multiplying the ratio between the first pixel data and the total pixel data or the ratio between the second pixel data and the total pixel data by the maximum measurement distance.