Ing C. Olivetti C., S.p.a.

Paolo Rivera

Marcello Boella

Pietro Musso

Ugo Carena

The printing device has, in addition to a line feeding device mounted upstream of the printing line to make the sheet advance incrementally, an extraction mechanism mounted downstream of the printing line in order to enable printing without smudging until the trailing edge of the sheet; the extraction mechanism including a couple of robber rollers and opposed pressure rollers having fine external teeth, which are selectively engaged, when the trailing edge of the sheet reaches a determined position, by means of cam driven levers.

Ink jet printing device and plain paper facsimile apparatus using the

An optical transducer for detecting the position of a rotary or translatory member comprises a light source, a photodetector group, and a shutter provided with a series of transparent elements spaced by opaque regions and interposed between the light source and the photodetector group. The photodetector group comprises an integrated circuit, on a surface of which is disposed a plurality of photovoltaic cells, each having an area which is a fraction of the area of each transparent element. The cells are divided into four groups to generate as many electrical signals which are out of phase relative to each other by 90.degree. and which are indicative of the position of the shutter with respect to the position of the photodetector group and the light source. The cells are disposed symmetrically with respect to a central radially extending optical axis, and in such a way that the barycenter of the areas of each of the four groups is included in the central optical axis. The sum of the four electrical signals is also used as feedback for controlling the power supply for the light source.

Optical position transducer having a plurality of photodetector cells of

An optical transducer for detecting the angular position of a rotary member with respect to a fixed structure, which comprises a shutter disc of transparent material, having two faces which are parallel to each other. The disc is provided with a plurality of radial shutter elements, spaced by elements which transmit the light. The shutter elements are formed by V-shaped elements provided on one face of the disc and capable of totally deflecting the light incident thereon.

Optical transducer with a transparent shutter disk

An optical transducer for detecting the angular position of a rotary member with respect to a fixed structure comprises a disc 13 mounted rotatably within a casing. The disc is provided with a plurality of opaque radial regions 19 which are spaced by transparent regions 18 which transmit the light emitted by a light source mounted on the casing. The light is received by a photodetector element 25 comprising a support plate 28 on which is disposed a multiplicity of photovoltaic cells 26 each having an area which is fraction of the area of each transparent region of the disc. The cells are subdivided into the groups A, B and C with different functions and phase positions and are distributed diffusely over the area encountered by the beam of light from the light source. The cells of each group are connected together in parallel to generate three electrical signals, one of which provides pilot control for the feed to the light source to stabilize the signals of the other two groups of photoelectric cells.

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Strambino, Italy

Paolo Rivera