Abstract: The invention relates to a point-by-point reading apparatus using a matrix of photodetector elements. The reading apparatus comprises a system of p groups of q basic elements, which are aligned, each of these basic elements being constituted by a photodiode and a diode insensitive to the light radiation and connected in opposition. These basic elements are addressed by an input circuit of the shift register type with p connections, each connected to all the diodes of the same group. The state of the photodiodes is collected in an output circuit with q connections, each connected to all the photodiodes occupying a particular rank in a group.

Abstract: Device for determining the reflective properties of objects in discrete spectral zones. The device has a housing in which there is disposed a diaphragm perpendicularly to the optical axis of the device and photosensors sensitive to light in a narrow spectral range that are connected with electronic amplifiers. The opening of the diaphragm coincides with the basic aperture of vision. Between the diaphragm and the object there are disposed supplementary diaphragms with openings coinciding with the basic aperture of vision. Each supplementary diaphragm lies in a plane determined by the intersection point of the parasitic aperture of vision of the diaphragm preceding it on the side of the photosensors and the housing. The device may be use to advantage in color discriminating systems, for example, the sorting of tobacco leaves according to their color.

Abstract: A safety device for a light signal generator only activates a laser beam emerging from an optical fiber connector when an optical fiber is connected. By inserting a plug of the optical fiber into the connector of the light signal generator a photodetecting circuit is caused to provide a control signal, which activates the laser.