Applied Materials, Inc.

Tektronix, Inc.

Morris H Green

Paul C Allen

Michael J Bohan

Henry Christopher Hamaker

A scanning system uses a multi-beam brush having a widely separated beams, a modulator that controls intensity of pixels in scan beams, an optical system that minimizes scan line bow at the expense of non-uniform scanning beam velocity, and a timing generator that generates a pixel clock signal having a variable period that compensates for the non-uniformity of pixel velocity. The wide separation of scan beams permits the modulator to turn beams on or off with a direction of brightening or darkening in the cross-section of the beams being opposite to the scanning direction. A novel arrangement of the beams in the brush permits a uniform indexing step size to uniformly expose an image region. In one embodiment, the timing generator includes: a source of pixel period values; a select circuit to select pixel period values for pixels, and a counter that loads a first value from the pixel period value selected for a pixel, counts for a period of time indicated by the first value, and asserts a signal marking an end of the period. An additional delay after the signal from the counter can be shorter than the period of a clock signal to the counter but also controlled by the pixel period value.

Scanning brush and method of use

Laser pattern generator

An electronic circuit is tested by applying a sequence of test vectors to the input port of the circuit as a plurality of sub-sequences each including at least one test vector. Serial scan vectors provided at a serial scan port of the circuit are examined after each sub-sequence, and determination is made as to whether a part of the serial scan vector indicates the presence of a defect in the circuit. In the event that a part of the serial scan vector indicates the presence of a defect in the circuit, information that identifies the number of serial scan vectors that have previously been examined and the part of the serial scan vector that indicates the presence of a defect in the circuit is made available for analysis.

Method of providing information useful in identifying defects in

A method of testing an electronic circuit of the kind having an input port for receiving input vectors, an output port for providing output vectors, and a serial scan port for providing at least one serial scan vector reflecting the status of predetermined elements within the circuit, is performed by applying a sequence of test vectors to the input port as a plurality of sub-sequences each including at least one test vector. The serial scan vector is examined after each sub-sequence, and a determination is made as to whether a part of the serial scan vector indicates the presence of a defect in the circuit. In the event that part of the serial scan vector indicates the presence of a defect in the circuit, the corresponding part of a succeeding serial scan vector is prevented from indicating the presence of a defect.

Growing community of inventors

Milwaukie, OR, United States of America

Morris H Green