Abstract: Methods and apparatus for truncating an image formed with coherent radiation. The optical relay system is adapted to form a line image at the image plane. The image is truncated by a variable aperture at or near the aperture plane conjugate to the image plane, to block progressively increasing portions of an incident coherent radiation beam used to form the line image. An apodizing pupil filter having a maximum transmission or reflection in the center and a transmission or reflection profile that varies with direction corresponding to long direction of the line image is provided in the pupil plane. The apodization is designed to prevent hot-spots from forming in the truncated image and ensures a relatively smooth, flat intensity profile. Thus, one end or another of a coherent line image scanned over a substrate can be truncated during scanning without substantially changing the image intensity extending into the product area.

Abstract: Methods and apparatus for truncating an image formed with coherent radiation. The optical relay system is adapted to form a line image at the image plane. The image is truncated by a variable aperture at or near the aperture plane conjugate to the image plane, to block progressively increasing portions of an incident coherent radiation beam used to form the line image. An apodizing pupil filter having a maximum transmission or reflection in the center and a transmission or reflection profile that varies with direction corresponding to long direction of the line image is provided in the pupil plane. The apodization is designed to prevent hot-spots from forming in the truncated image and ensures a relatively smooth, flat intensity profile. Thus, one end or another of a coherent line image scanned over a substrate can be truncated during scanning without substantially changing the image intensity extending into the product area.

Abstract: An infrared illumination system for a digital camera having a taking lens, includes: a plurality of infrared emitting diodes arranged around the taking lens, each diode being contained in a can having an infrared transparent window; a first diffuser located over the windows of the cans; and a second diffuser spaced apart from the first diffusers. The first diffuser is a new type of diffuser called a Fourier transform holographic diffuser.

Abstract: A real-time calibration instrument on a processless writing device reads a pattern of marks produced by the device and adjusts writing parameters in real time through feed back mechanisms to modify the characteristics of the marks and their pattern. The calibration instrument includes a photoelectronic camera defining an optical axis perpendicular to the recording medium, and the marks are illuminated coaxially along the same axis to capture an image of the marks without distortion. According to other features, the recording medium is rotated on a drum relative to the recording head and the illumination is provided by a stroboscopic source synchronized with rotation of the drum.