An apparatus for marking a recorded signal includes means for generating and storing a marking signal comprising at least two codes which are mutually in phase quadrature. The codes are converted to analogue signal and are used to phase-shift modulate the signal to be recorded, the modulating means performing the function of a single side band modulator on the signal to be recorded.

Apparatus for marking a recorded signal

The present invention provides a sheet conveying apparatus, and an image reading apparatus and an image forming apparatus having such a sheet conveying apparatus, in which skew correction of a sheet can be effected with high accuracy. A sheet convey means is provided at an upstream side of a skew correction means for correcting skew-feed of a sheet, and the sheet convey means is shifted by a shift means in a direction substantially perpendicular to the sheet conveying direction. A control means drives the shift means to shift the sheet convey means pinching the sheet to be skew-corrected by the skew correction means by a distance corresponding to a sheet skew amount on the basis of sheet skew amount information from a sheet skew amount detection means for detecting a skew amount of the sheet, thereby shifting the sheet in a skew correction direction.

Sheet conveying apparatus

The density of pixel samples across a document is determined by employing a constant scanner sensing head sampling rate and driving the scanner head movement at a rate directly correlated to the preselected density level. The scanner operator determines the particular density and introduces a signal to motor drive controls to cause it to move across the image at the preselected rate.

Direction scaling method and apparatus for image scanning resolution control

A disc drive (22) having a head (28) actuated by an actuator (27) includes a head loading velocity control for successfully and accurately loading the head (28) onto a disc (26) so as not to cause damage to the head (28) or the disc (26).

Head loading velocity control.

Mode selection switches (76, 96, 98) selectively interconnect a sensor line shift timing generator (76) with one of three signal sources - (1) a conventional raster scan timing signal from a raster scan sync generator (70), (2) variable speed external timing signals from a tachometer (32), and (3) fixed speed timing signals developed from the horizontal timing signals of the raster scan sync generator. In a time delay and integration mode, the sensor line shift timing generator causes the CCD arrays of an image section (22) and storage section (24) to shift pixel values down the CCD arrays at a rate commensurate with the external timing signal. As a spot of light emanating from a portion of an object moving through an examination region moves along the CCD array, a corresponding pixel charge is shifted through the CCD array at the same speed such that the same pixel charge integrates light from the same spot as it moves the entire length of the CCD array. An output register timing generator (80) generates timing signals for output registers (26) such that an output signal is produced that is compatible with EIA-170 television signal standard. In the conventional raster scan mode, the camera works as a conventional video camera. When connected to the variable frequency timing signal, the video picture scrolls down the TV monitor clocked by the tachometer in proportion to the speed of the conveyor. In the calibration mode, the image scrolls down the video screen at a fixed rate.

Multi-mode TDI/raster-scan television camera system

A digital to analog converter (DAC) for converting a digital signal (DS) having a maximum voltage range which corresponds to a first supply voltage (UL) into an analog signal (UOUT) having a maximum voltage range which corresponds to a second supply voltage (UH). The first supply voltage (UL) is offered between a first supply terminal (VSS) and a second supply terminal (VDDL). The second supply voltage (UH) is offered between the first supply terminal (VSS) and a third supply terminal (VDDH). The digital to analog converter (DAC) comprises conversion resistors (RCNV0 - RCNVn) and coupling means (CPL) for coupling a number of said conversion resistors (RCNV2 - RCNVn) in between the first supply terminal (VSS) and an output terminal (OUT), and for coupling the remainder of said conversion resistors (RCNV0 - RCNV1) in between the third supply terminal (VDDH) and the output terminal (OUT). The value of said number depends on the data content of the digital signal (DS). Digital to analog converters are generally implemented in ICs. For modern ICs there is a trend toward ever decreasing supply voltages. Often circuits implemented in new IC processes have to be able to interface with ICs processed in less modern processes which are generally operated on higher supply voltages. In the modern process, therefore, circuits designed in modern ICs have to cope with voltages which are above the maximum specification for their transistors or other components. The DA-converter (DAC) mentioned above fulfils this requirement by the fact that material, such as polycrystalline silicon, is used for the conversion resistors (RCNV2 - RCNVn), which material can cope with relatively high voltages, and furthermore by the fact that only the coupling means (CPL) have to be designed to cope with relatively high voltages.

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Digital to analog converter

A variable time integrating period to accomplish distortion free synchronization of the scanning rate to the document transport speed when the transport speed is within a predetermined tolerance with respect to it's nominal speed is disclosed. The data levels provided by the scanner are then multiplied by an appropriate correction factor to compensate for the varied amount of light accumulated by the time integrating photo sensor array because of the varied integration time. When the document speed must be reduced to a value less than the predetermined tolerance, the system of the invention resorts to the technique of selecting only certain scans and discarding the data from other scans. Scan selection is found to be economically accomplished by selecting those scans which were time integrating when an emitter pulse occurred.

Solid state scanner for a variable speed transport

A diskette identifying code is written in each sector on a flexible disk used in a flexible disk recorder. The diskette identifying code can be read from any track on the flexible disk and used to log the occurrence of insertion or removal of the diskette at the flexible disk recorder. Also, the diskette identifying code can be read from any accessed track prior to a write operation on that track in order to verify that the diskette has not been changed by the operator since the last access to the flexible disk.

Method for checking disk identity in a flexible disk recorder

A magnetic head or transducer assembly for cooperating with a relatively moving magnetic medium and for reading and/or writing a track of magnetic information on the medium and for erasing the edges of the track and old information adjacent to the edges of a newly written track. The head comprises a central magnetic core with a gap on an active face of the head assembly and with a read/write coil on the magnetic core and comprises a pair of additional, erase magnetic cores on opposite sides of the central magnetic core and forming a pair of erase gaps on the active face of the head assembly. A single erase coil is disposed on opposite legs of the erase cores, and an L-shaped side bar completes the erase magnetic circuit for both of the erase cores and lies on one end of the erase coil and provides an air gap between it and the ends of each of these erase core legs so as to cause the action of the two erase gaps to be equal in their erasing action.

Read/write and tunnel erase magnetic head assembly

A control system for applying a magnetic head onto a magnetic disk in random places thereon including a free running oscillator and switching means responsive to pulses from said oscillator and a head load command signal derived from the disk during a revolution thereof for initiating the energization of a head engaging solenoid. The system includes a capacitor which is charged at various rates to produce an initial fast rising current in the solenoid for moving the head into close proximity with the disk, a slowly rising subsequent current in the solenoid for engaging the head with the disk gradually, and a final fast rising current in the solenoid for completing the engagement of the head on the disk.

Jeffrey L. Lovgren

Papers

Digital to analog converter

Solid state scanner for a variable speed transport

Method for checking disk identity in a flexible disk recorder

Read/write and tunnel erase magnetic head assembly

Magnetic head load control system