Abstract: In public videotex (Btx) terminals, different pages are displayed successively on the screen in the off-line mode (e.g., advertisements and user instructions). To be able to update such off-line pages at low cost, a page memory in the terminal is constructed as a random-access memory (46). A central operating facility contains an editing device in which the information and control characters required to display an off-line page are produced. These characters are transmitted to the terminal and written into the random-access memory (46). This may be effected automatically when the supply voltage is turned on.

Abstract: A coherent light image generator for signal processing such as image correlation directs laser light onto a specularly reflecting matrix addressed dyed nematic liquid crystal display device having a liquid crystal layer sandwiched between a transparent electroded front plate and an active single crystal silicon wafer incorporating NMOS circuitry.

Abstract: An improved selector mechanism is described for use in a sheet feeder that has a plurality of bins and a feedout roller shaft associated with each bin, for selecting which of the feedout rollers to rotate, the selection being made by determining the angles at which rotation of a drive member is reversed. Each selector includes a cam assembly connected to the feedout roller shaft by a one-way clutch, and a driven driver which is freely rotatable on the shaft. The driver carries a pivotally mounted arm. The cam assembly has a deflector which moves the arm to a deflected position when the arm rotates in a nonfeed direction, and also carries an arm engager which engages the deflected arm when the driver reverses rotation after the arm is deflected, so the driver rotates the cam and, therefore, the feedout roller shaft in a feed direction. The cam also carries an undeflector which moves the arm back to its undeflected position if the driver rotates too far beyond the point of its encounter with the deflector.

Abstract: Apparatus to support an inked ribbon cartridge and/or daisywheel motor and assembly. The cartridge has a paper shield integral therewith that is notched to expose the ribbon to the paper, whereby a daisywheel petal carrying a type font may be struck by a print hammer to type a character. The cartridge has a detent to lock the daisywheel motor support in a fixed position. The motor support may be adjusted in position relative to the platen.

Abstract: In a signal generator with a magnetic rest, consisting of a ferromagnetic studded disk (13) with a U-shaped part (6) consisting of a permanent magnet (3) and lateral ferromagnetic small plates (4,5), two brackets (7, 8) are provided for on a support (1) between which the permanent magnet (3) and the small plates (4, 5) are capable of being clampingly inserted. This permits an easy assembly and adjustment of the permanent magnet (3) as well as of the small plates (4, 5).

Abstract: The monitor screen housing of a CRT type computer terminal forms a monitor module; the base thereof housing the power supply and the electrical interface to other computer equipment forms a base module. The two modules are mechanically and electrically connected to one another in such a way that the monitor module may be supported by and swiveled with respect to the base module and yet may be readily disconnected therefrom. The base module is provided with a raised central region which includes an electrical connector and a circular locking ring having a plurality of horizontally projecting teeth. The monitor module is provided with a recessed central region which includes an electrical connector complementary to that of the base module and a circular locking ring having horizontally projecting teeth that fit between those of the base module only when the base and monitor modules have a predetermined orientation.

Abstract: A disc is provided which centers itself on motor shafts that vary somewhat in diameter. The disc is formed of a single sheet of material with a central hole for receiving the shaft and with a group of fingers projecting slightly into the hole to engage a shaft. The fingers are formed by pairs of slots that extend from the edge of the central hole and radially outward to form fingers of considerable length which can be bent out of the plane of the disc to engage shafts of varying size. The radially inner tips of the fingers lie precisely on an imaginary circle which is slightly smaller than the minimum diameter of a shaft, and the fingers deflect uniformly to hold the shaft centered on the axis of the disc.

Abstract: To enable a microprocessor to operate within its bandwidth limitations while controlling a serial printer, means are provided for adjusting the microprocessor system clock rate when the printer is in its rate mode. In particular, the output of a counter clocked by the pulses from an encoder representing the velocity of a member is controlled; the output of the counter being selectively applied to the microprocessor in accordance with the velocity of the member being controlled.

Abstract: A co-ordinate matrix addressing system is used to address a liquid crystal display cell containing a positive dielectric anisotropy smectic material. For this purpose one or more direct voltage pulses are applied across selected elemental volumes of the display to convert them from a focal-conic scattering state to a homeotropically aligned state. Prior to this all elements are electrically driven into the turbulent scattering state which relaxes into the focal-conic scattering state upon removal of the driving field. The driving field may also take the form of direct voltage pulses. Unselected elemental volumes may be refreshed to substantially their original level of focal-conic scattering by means of a suitable blanking potential applied to both selected and unselected elemental volumes which nevertheless leaves previously restored elemental volumes in the homeotropically aligned state.

Abstract: A shell-less connector member having an optional grounding shell bracket mounted on the forward mating portion of the connector member. The connector member may be intermated with a standard metal shell connector member or, when the grounding bracket is removed, with the mating shell-less connector member.

Abstract: A curtailed drive scheme for a matrix array liquid crystal display cell in which the field developed across each picture element is maintained for only a fraction of the time interval between consecutive addressings. This reduces the effects of differences in time constants across the display for addressing schemes in which the average time constant is short compared with this time interval between consecutive addressings.

Abstract: A liquid crystal display device has a tandem arrangement of two cells. The rear cell is an active silicon matrix backed dyed nematic cell with 180.degree. twist cell affording the possibility of grey scale representations. The front cell is a dyed nematic cell oriented to act as a variable density polarizer to absorb the weakly absorbed plane of the rear cell. Control of this absorption is used to optimize the contrast perception in the rear cell under different ambient lighting conditions.

Abstract: The disclosed invention relates to an electro-optical device for use with a facsimile printer, telecopier, etc., designed to accommodate line-at-a-time output of picture information with the aid of an electrically controllable electro-optical substrate. In particular, there is disclosed a solution to the problem of adjusting the electro-optical elements to provide the desired rectilinear output of picture information. The electro-optically active substrate (1) is supported in a frame-like housing (17) such that it may be adjusted perpendicularly relative to a longitudinal edge (18) of the substrate (1) by means of an adjustable ledge (31) and a resilient support (33). A beam of light from a light source (37) is shaped and directed onto the substrate by means of a light-shape converter (36) which can be adjusted relative to the substrate by means of a cross slide arrangement (51, 57) having 2.degree. freedom.

Abstract: A printer having a print wheel rotatable on a carriage. The carriage is guided for movement parallel to a platen. The printer may print at either a fast speed for draft quality output, or a slower speed for highest quality output. The lesser quality of output produced at the fast speed is more than adequate for draft documents.

Abstract: Above the platen and throughout the entire width of the paper guide, the back of a guide member which is inclined in the direction of the paper eject, is firmly arranged. On bolts in the end faces pairs of levers are swivel mounted which, via tooth segments, lie in engagement with one another. Between each of the levers there is arranged a tension spring. The front levers are in connection with one another by a shaft on which pressure rolls are seated. Between the levers and firmly connected thereto, there is arranged a paper-tearing device. The rearward levers are provided with oblong holes in which a rod is resiliently supported.

Abstract: A method of operating a homeotropically aligned smectic liquid crystal cell in which the cell is turned from a clear to a scattering state by illumination with an intense flash of light after which a focused laser beam is scanned across the layer to leave clear tracks where homeotropic alignment has been restored thereby producing a display providing, in projection, bright lines on a dark background.