Abstract: In a thermal printer the transfer ribbon such as one having sets of transverse color stripes is guided over of a ribbon support which carries the heat applying print head. The ribbon support is movable relative to the paper by an eccentric to move the ribbon into and out of contact with the paper. A support beam and a guiding roller are provided immediately behind print area to guide the ribbon away from the paper path in an angle of more than 45 degrees. This assures a separation of the ribbon from the paper essentially normal to its surface, thus avoiding shear upon relative movement between paper and ribbon and negates the need for a relatively bulky ribbon carrier material.

Abstract: A display refresh system wherein a RAM refresh buffer is tightly packed. Line start addresses in the buffer are determined by the line length such as eighty characters. With each of the lines in the refresh buffer being normally a binary number such as 128 characters in length the line start addresses are such that they do not coincide with the beginning of each line in the buffer. To assure packing they are interspersed each 80 positions sequentially within the buffer. A processor loads the address of each line start character into the pointer area of the refresh buffer. A line counter is used which counts the lines being displayed on the display. The RAM refresh buffer which contains the line start addresses and character data is first addressed by the line counter output to provide the line address. Since the refresh buffer is used as the line pointer register the output bus for pointer data and character data is common.

Abstract: A computer system having a CPU connected to I/O devices via a channel sets addresses into the I/O devices by the CPU. The I/O devices, for purposes of control, are grouped in types. To load device addresses or identifiers, the processor sends a type identifier to the I/O devices. The device having the highest ordered priority of the same type of device and which does not have an assigned identifier responds by inhibiting all lower ordered devices of its type. It is then loaded with its unique assigned identifier which results in the setting of a status latch therein. This setting allows the next lowest ordered device of the same type of devices to then be assigned and loaded with an identifier by the processor. This process continues until all I/O devices of the same type are loaded with identifiers. The process is then repeated for each other type of I/O devices in the system.

Abstract: A print hammer drive circuit is driven by a voltage supply having inherent voltage variations. The driving current is applied to the print hammer coil and the level of the current in the coil detected. After the level of the current in the coil reaches a predetermined maximum level a timing circuit is initiated to control the duration of application of maximum current. Variations in supply voltage on the duration and force of strike of the print hammer have greatly reduced since all timing is based relative to the time that the predetermined drive current level is achieved as distinguished from timing which includes the rise time of the driving current wave form. Also the effects of variations in inductance from coil to coil can be compensated for by adjustment of the timing circuit.

Abstract: A damping control system for a three phase stepper motor. A reluctance velocity transducer is used for each of the three phases. The output of each of the transducers is proportional to the rotational velocity of the motor. Each of the transducers is rotationally phase shifted 3.75 with respect to one another and phased to the motor rotor rotationally such that the zero voltage crossings of the transducers correspond to the zero torque crossings of the motor. During damping or detenting of the motor the selected phase has current applied to it which is equal to a predetermined fixed value plus the feedback from its associated transducer. The windings on each side of the detent position have current applied to them which is proportional to the voltage from their respective feedback transducers. The voltage in each of the windings is amplified by a selected gain constant.

Abstract: Disclosed is an alignment assembly for accurately aligning separate sets of documents being inserted into the assembly from transversely oriented feed paths, the alignment assembly including a pivotally mounted document gate which provides not only guide passageways for documents entering the assembly, but also an alignment edge for accurately positioning and aligning documents within the assembly in document clamps adapted to transport the documents from the alignment assembly to a print station and thereafter to an exit transport assembly. The movement of documents inserted in the alignment assembly is effected by a document aligner assembly comprising cooperating vibratory document transporters and pivotally mounted back-up rollers for simultaneously urging the documents into the clamps and against the alignment edge of the document gate.

Abstract: Disclosed is document transport apparatus for advancing documents between two locations, for example between the printing and output stations of copying equipment, the transport apparatus including a high friction continuously driven belt cooperating with a stationary strip of low friction material to define a transport guideway path for the documents with document pinch points being defined along spaced locations of the guideway path. The continuous belt is preferably of a cross-sectional size and configuration to transportably engage the documents along a line contact at, or immediately adjacent, the edge thereof.

Abstract: Disclosed is a method and apparatus for detecting the presence of signals, particularly touch-tone signals, of characteristic complex waveforms by comparing unknown signals with pre-specified digital formats or "masks" representative of such waveforms. The apparatus includes digital circuitry defining the masks and digital circuitry for counting the number of times during a prescribed time period there is a correlation between the digital format of the unknown signals and the masks.

Abstract: In the IBM Mag Card II, data read from the cards into the shift register buffer can be scanned without printing the data out and rerecorded on a magnetic card with proper pagination decisions made based on an operator entered line count. A system is provided for printing out a reference line near the end of each page based on the operator entered line count such that the operator can determine that the page has ended at a proper point. In addition, the system provides a control technique such that when a sufficient number of lines have been scanned to satisfy the line count, the reference print line will neither be the next to the last line of a paragraph nor the first line of a paragraph. This control is in accordance with established word processing procedures in that it is undesirable to end the page with the first line of a paragraph or to begin a subsequent page with the last line of a paragraph. Logic is provided to accomplish this printout in accordance with the above rules.

Abstract: Disclosed is document feed apparatus including a cooperating roller assembly for separating and feeding individual documents from a stack to utilization apparatus, the roller assembly including rotatably powered separator, restraint, and picker rollers, the picker roller being mounted to pivot out of and into engagement with the document stack. Control means responsive to each document passing through the roller assembly lifts and drops the picker roller from and into engagement with the stack, the momentum of the dropping picker roller assembly effective to switchably actuate motive means for incrementally elevating a vertically movable document support platform to continually reposition the top of the document stack in alignment with the roller assembly.

Abstract: A document transport and separating device which utilizes opposing intermittent motion imparting devices having tips, the end of which are caused to move in an elliptical manner to feed, separate and align documents such as sheets of paper. One end of the tips of the devices are caused to move in an elliptical manner through a combination of application of an intermittent force parallel to the longitudinal axis of the tips of the device at its other end coupled with a rotational movement about a mounting spring which converts the longitudinal force into the elliptical motion. The longitudinal force is applied by pulsing a solenoid or electro magnet. The tips of the opposing devices are flattened at their point of intermediate contact to prevent multiple sheet feeding and greater surface contact and the coefficients of friction of the flattened tip surfaces are greater than the coefficients of friction between each of the sheets such that sheet feeding occurs.

Abstract: Disclosed is a rotatably powered roller feed assembly for transporting documents from a stack in a forward feed direction toward utilization apparatus, a clockspring appropriately coupled to the feed assembly for rotatably powering the feed rollers in a direction opposite to the feed direction of rotation in order to drive documents out of, and to therefore clear, the nip point of the roller assembly. The reverse rotation is initiated at the end of each feed cycle by control means, including an optical sensor assembly responsive to a document exiting the nip point, interrupting the powering of the roller assembly in the feed direction.

Abstract: An unattended printing system in which the operator keys in a page line count defining the number of lines to be printed on a page from codes derived from a shift register memory which is automatically loaded from a pack feed magnetic read/recorder. Logic is provided which, in the event that the text being played out does not equal a full page, automatic indexes or carrier returns will be generated to cause the page to be fed such that the printing mechanism is then in alignment with the first line of the next page. While page feeding occurs the memory is also automatically cleared; a new card is fed and reading of new codes into the shift register initiated. In addition, in the event that the margins on the machine which is being used for playout differ from the margins which were used during source recording, in the event that a fewer number of lines of text result, the proper number of indexes for this fewer number of lines to cause proper alignment on the next page will be output.

Abstract: A driving circuit for driving a number of solenoid type devices which have very accurate voltage requirements and which utilizes the inductive kick of both the driven devices and internal transformers to efficiently utilize power. A feedback path is provided to an integrated circuit regulator to provide an indication of the power being consumed by the devices. The integrated circuit regulator, along with accompanying circuitry, regulates the voltage output by a power driver such that the voltage output remains steady regardless of the number of solenoid type devices which are being operated. In addition, a feedback path is also provided from each of the driven devices and the internal transformers to the power source such that when the devices are deenergized logically, the inductive kick from each of the devices and the transformers is applied to the power source for power conservation as well as to prevent the necessity for having heat sinks to dissipate the power.