Distance measurement sensor

Measurement sensor comprising:

• a PSD (30) as an optoelectronic receiver;
• a target (24);
• a transmitter (10, 12) for generating spots (22, 26) on a target;
• optics (14, 32) for producing spots (22′, 26′) on said PSD (30) corresponding to spots (22,26) on said target;
• said PSD) generating output signals (I1,I2) depending on the position of said spots (22′, 26′) on said PDS (30);
• current amplifiers (44, 46) which amplify current signals (I1, 12);
• a digitally controlled potentiometer (48), said digitally controlled potentiometer includes a variable position wiper;
• a differential comparator (50);
• said differential comparator has a first voltage input V1 and a second voltage input V2, a CPU (52) for processing said output signals (I1, I2) generated by said PSD) (30) and for controlling said transmitter (10, 12) depending on said amplified output signals (I1, I2) in order to measure the distance between said spots on said target (24) and said sensor by a triangulation technique, said transmitter comprises at least two optoelectronic signal sources (10, 12) for projecting said spots (22, 26) independently from each other on said target (24), said amplifiers (44, 46), said digitally controlled potentiometer (48), said comparator 50, and said CPU (52) controlling said potentiometer (48) as a function of the amplified magnitudes of I1 and I2 such that said voltages V1 and V2 are equal and said wiper positions of said digital potentiometer corresponding to said equal voltages V1 and V2 for said spots (22, 26) being stored in EPROM.