Optical sensor device with reduction of ambient light effects

An apparatus for producing a light signal intermittently incident on an image sensor which produces an electric charge, comprising:

• (a) first memory means operatively connected to the image sensor for storing a quantity of the electric charges produced by the image sensor;
• (b) second memory means operatively connected to the image sensor for storing a quantity of the electric charges produced by the image sensor;
• (c) first control gate means connected between the image sensor and the first memory means for permitting transfer of said electric charge to the first memory means while the light signal incident on the image sensor is present;
• (d) second control gate means connected between the image sensor and the second memory means for permitting transfer of said electric charge to the second memory means while the light signal incident on the image sensor is absent;
• and
• (e) comparison means operatively connected to the first and second memory means for producing an electrical output signal corresponding to the difference between the electric charges stored in said first and second memory means.

An apparatus for processing a light signal intermittently incident on an image sensor which produces an electric charge, comprising:

• (a) first memory means operatively connected to the image sensor for storing a quantity of the electric charges produced by the image sensor during a certain interval when the light signal falls on the image sensor;
• (b) second memory means operatively connected to the image sensor for storing a quantity of the electric charges produced by the image sensor during a certain interval in the absence of the incident light signal;
• and
• (c) comparison means operatively connected to the first and second memory means for producing an electrical output signal corresponding to the difference between the electric charges stored in said first and second memory means.

An apparatus for producing a light signal intermittently incident on an image sensor which produces an electric charge, comprising:

• (a) first memory means operatively connected to the image sensor for storing a quantity of the electric charges produced by the image sensor while the light signal falls on the image sensor;
• (b) second memory means operatively connected to the image sensor for storing a quantity of the electric charges produced by the image sensor in the absence of the incident light signal;
• and
• (c) comparison means operatively connected to the first and second memory means for producing an electrical output signal corresponding to the difference between the electric charges stored in said first and second memory means.

An apparatus for processing a light signal intermittently incident on an image sensor which produces an electric signal, comprising:

• (a) first means operatively connected to the image sensor for detecting a quantity of the electric signals produced by the image sensor during a certain interval when the light signal falls on the image sensor;
• (b) second means operatively connected to the image sensor for detecting a quantity of the electric signals produced by the image sensor during a certain interval in the absence of the incident light signal;
• and
• (c) output means operatively connected to the first and second means for producing an electrical output signal corresponding to the difference between the electric signals detected by the first and second means.

An apparatus for processing a light signal intermittently incident on an image sensor which produces an electric charge, comprising:

• (a) first memory means operatively connected to the image sensor for storing a quantity of the electric charges produced by the image sensor;
• (b) second memory means operatively connected to the image sensor for storing a quantity of the electric charges produced by the image sensor;
• (c) first control gate means connected between the image sensor and the first memory means for permitting transfer of said electric charge to the first memory means during a certain interval when the light signal incident on the image sensor is present;
• (d) second control gate means connected between the image sensor and the second memory means for permitting transfer of said electric charge to the second memory means during a certain interval when the light signal incident on the image sensor is absent;
• (e) comparison means operatively connected to the first and second memory means for producing an electrical output signal corresponding to the difference between the electric charges stored in said first and second memory means;
• (f) third control gate means for transferring a quantity of the electric charges stored in the first memory means to said comparison means when the first control gate means have repeated a plurality of transfer operations, said gate means being inserted between said first memory means and said comparison means;
• and
• (g) fourth control gate means for transferring a quantity of the electric charges stored in the second memory means to said comparison means when the second control gate means have repeated a plurality of transfer operations.