Solar cell anomaly detection method and apparatus

A method for detecting anomalies in a photo sensitive device that has electrical terminals for producing an output dependent upon incident light, comprising:

• directing a narrow light beam which covers a small portion of the light sensitive area of the device successively onto different areas of the device;
• sensing the variation in electrical output from said terminals as said beam covers said different areas of the device;
• and
• directing a bias light source onto said photo sensitive device to cover substantially all of the light sensitive area thereof, while directing said narrow light beam onto small portions of the light sensitive area, with said bias light source illuminating said device at a lower intensity than said narrow beam.

A method for detecting anomalies in a photo sensitive device that has electrical terminals for producing an output dependent upon incident light, comprising:

• directing a narrow light beam which covers a small portion of the light sensitive area of the device successively onto different areas of the device;
• sensing the variation in electrical output from said terminals as said beam covers said different areas of the device;
• directing a bias light source onto said photo sensitive device to cover substantially all of the light sensitive area thereof, while directing said narrow light beam onto small portions of the light sensitive area;
• and
• modulating the intensity of said narrow light beam and filtering the output of said device at the modulating frequency.

Apparatus for detecting anomalies in a photo sensitive device that has electrical terminals for producing an output dependent upon incident light, comprising:

• means for moving a narrow light beam in a scanning pattern along said photo sensitive device;
• memory means responsive to said light beam moving means for storing a succession of signals representing the level of output from said device as the beam is moved to a succession of locations on the surface of the device;
• and
• means coupled to said memory means for repeatedly generating a raster pattern on the screen of a cathode ray tube means, with the intensity of different points on said screen controlled by different signals stored in said memory, whereby to enable clear viewing of the pattern on a cathode ray tube of the effects of a beam that is scanned over the device during an extended period of time.

Apparatus for detecting anomalies in a photo sensitive device that has electrical terminals for producing an output dependent upon incident light, comprising:

• means for directing a narrow light beam which covers a small portion of the light sensitive area of the device, successively onto different areas of the device;
• means for sensing the variation in electrical output from said terminals as said beam covers said different areas of the device;
• and
• means for directing a bias light source onto said photo sensitive device to cover substantially all of the light sensitive area thereof but at a lower intensity than said narrow beam.

Apparatus for detecting anomalies in a photo sensitive device that has electrical terminals for producing an output dependent upon incident light, comprising:

• means for directing a narrow light beam which covers a small portion of the light sensitive area of the device successively onto different areas of the device;
• means for sensing the variation in electrical output from said terminals as said beam covers said different areas of the device;
• means for directing a bias light source onto said photo sensitive device to cover substantially all of the light sensitive area thereof;
• and
• means for modulating the intensity of said narrow light beam and filtering the output of said device at the modulating frequency.