Distance image sensor

A distance image sensor for projecting light from a light source to an object intermittently and measuring the distance by the delay time of the reflected light thereof, comprising:

• a photo-detector for converting reflected light from an object into charges;
• an inversion amplifier to which signal charges from said photo-detector are input;
• a first serial circuit further comprising a first capacitor (C1) and first switching means (Φ1) connected to said first capacitor in series;
• a second serial circuit further comprising a second capacitor (C2) and second switching means (Φ2) connected to said second capacitor in series;
• and
• control means (6) for controlling the switching of said first and second switching means, wherein
• said first serial circuit is connected between the output and the input of said inversion amplifier, and said second serial circuit is connected between the output and the input of said inversion amplifier to construct a negative feedback amplifier, signal charges which depend on the delay time of the reflected light from an object are distributed to said first capacitor and said second capacitor by switching of said first and second switching means, so that the charge transfer efficiency from said photo-detector is improved and information on distance to the object is acquired from the charges stored in said first and second capacitors.

A distance image sensor for projecting light from a light source to an object intermittently and measuring the distance by the delay time of the reflected light thereof, comprising:

• a photo-detector for converting reflected light from an object into charges;
• an inversion amplifier to which signal charges from said photo-detector are input;
• a first serial circuit further comprising a first capacitor (C1) and first switching means (Φ1) connected to said first capacitor in series;
• a second serial circuit further comprising a second capacitor (C2) and second switching means (Φ2) connected to said second capacitor in series;
• control means (6) for controlling the switching of said first and second switching means, wherein
• said first serial circuit is connected between the output and the input of said inversion amplifier, and said second serial circuit is connected between the output and the input of said inversion amplifier to construct a negative feedback amplifier, signal charges which depend on the delay time of the reflected light from an object are distributed to said first capacitor and said second capacitor by switching of said first and second switching means, so that the charge transfer efficiency from said photo-detector is improved and information on distance to the object is acquired from the charges stored in said first and second capacitors and
• wherein the r (r=1, 2, . . . n)-th capacitor for holding is connected to the output of said inversion amplifier via the r-th gate, the charges stored in said r-th capacitor are transferred to said r-th capacitor for holding by opening said r-th gate corresponding to the closing of said r-th switching means, and sampling & holding operation of charges is performed, so that calculation is enabled for all the pixels simultaneously.

A distance image sensor for projecting light from a light source to an object intermittently and measuring the distance by the delay time of the reflected light thereof, comprising:

• a photo-detector (PD) having a photo-diode structure buried in a semiconductor substrate for converting reflected light from an object into charges;
• a plurality of gate means (G1, G2) having an MOS (Metal Oxide Semiconductor) structure on a semiconductor substrate;
• a plurality of charge storage nodes (C1, C2);
• control means (6) for controlling the switching of said gate means, wherein
• at least two of said charge storage nodes, that is a first charge storage node and a second charge storage node, charges from said photo-detector are alternately transferred and stored, synchronizing the light intermittent operation from said light source, by said gate means, that is a first gate means and a second gate means, so that the charge transfer efficiency from said photo-detector is improved and the distance to the object is determined using the distribution ratio of the stored charges and
• voltage control delay means for passing signals for controlling the switching of said first and second gate means or switching means, wherein a signal based on the difference of the charges stored in said storage node or capacitor is supplied to said voltage control delay means as a control signal with polarity where said difference of charges approaches zero, so as to form a negative feedback loop.

A distance image sensor for projecting light from a light source to an object intermittently and measuring the distance by the delay time of the reflected light thereof, comprising:

• a photo-detector for converting reflected light from an object into charges;
• an inversion amplifier to which signal charges from said photo-detector are input;
• a first serial circuit further comprising a first capacitor (C1) and first switching means (Φ1) connected to said first capacitor in series;
• a second serial circuit further comprising a second capacitor (C2) and second switching means (Φ1) connected to said second capacitor in series;
• control means (6) for controlling the switching of said first and second switching means, wherein
• said first serial circuit is connected between the output and the input of said inversion amplifier, and said second serial circuit is connected between the output and the input of said inversion amplifier to construct a negative feedback amplifier, signal charges which depend on the delay time of the reflected light from an object are distributed to said first capacitor and said second capacitor by switching of said first and second switching means, so that the charge transfer efficiency from said photo-detector is improved and information on distance to the object is acquired from the charges stored in said first and second capacitors and
• voltage control delay means for passing signals for controlling the switching of said first and second gate means or switching means, wherein a signal based on the difference of the charges stored in said storage node or capacitor is supplied to said voltage control delay means as a control signal with polarity where said difference of charges approaches zero, so as to form a negative feedback loop.