Abstract: A scanning device comprises a paper holding member for holding paper to be scanned, paper feeder for continuously feeding the paper in a first direction at substantially a constant speed, scanning unit for scanning the paper in a second direction substantially perpendicular to the first direction, scanning areas scanned in two successive scanning cycles by the scanning unit being partly overlapped on each other, memory for storing data supplied from the scanning unit, and control unit for deriving column data each formed of a plurality of bits from the scanning unit at a regular interval for each row and sequentially storing the derived column data into the memory, detecting the overlapped bit number between two successive scanned data by comparing each column data of one of the two successive scanned data and corresponding column data of the other scanned data, and cancelling the detected number of overlapped bits from each column data of one of the two successive scanned areas.

Abstract: A thermal printer includes a thermal head having n heating elements arranged at a preset pitch D1 in a line, a memory including a first memory area storing a plurality of high speed printing character data each column of which is composed of n-bit data and a second memory area storing a plurality of high resolution printing character data each column of which is composed of m-bit data (m>n); and printing control circuit which reads out the m-bit data of each column designated by the input character code data from the second memory area in accordance with the high resolution printing mode designation data, and drives the thermal head in accordance with the m-bit data read out.

Abstract: A thermal printer includes a thermal head pressed against a paper sheet on a platen directly or through an ink ribbon, a carrier which holds the thermal head and on which a black or color ink ribbon is detachably mounted, a first detector for generating a color output signal upon detecting that a color ink ribbon cassette is mounted on the carrier, a second detector for generating a "black" signal while detecting a black area of the ink ribbon, and a control circuit for setting a thermal printing mode, a black or a color ink printing mode in accordance with the output signals from the first and second detectors. When the thermal printer is powered, the control circuit sets the color ink printing mode upon detecting that the color output signal is continuously generated from the first detector. When the color output signal is not generated from the first detector, the control circuit moves the thermal head by a given distance upon pressing it against the paper sheet on the platen.

Abstract: A thermal printer includes a CPU which reads out a corresponding character data from an ROM in accordance with a character specifying data from a host computer and selectively allows currents to flow through thermal resistors of a thermal head in accordance with the n-bit dot pattern data which constitutes the readout character data. A size data representative of the size of the picture element of the character to be printed is further generated from the host computer. The CPU converts the n-bit dot pattern data into the dot pattern data of the number of bits designated by the size data and selectively allows the currents to flow through the thermal resistors in accordance with this converted dot pattern data.

Abstract: In a thermal printer of this invention, a detector detects whether a ribbon cassette exists or not, and the thermal printer is automatically changed in thermal sensitive process or thermal transfer process by installing or detaching the ribbon cassette.

Abstract: A thermal printer is provided, wherein a carrier having a thermal head mounted thereon is driven in both directions and a printing ribbon is fed in an amount necessary to print data in each printing operation. In this thermal printer, a ribbon drive means for driving the ribbon is provided separately from the carrier 20, thereby feeding the ribbon by the distance to be determined in accordance with the front end position of the unused portion of the ribbon and the length of the ribbon necessary to print the print data.