Minolta Camera Kabushiki Kaisha

Naoya Misawa

Yoshikazu Sasaki

A laser-beam image recording apparatus for recording images on a light-sensitive sheet medium through irradiation of an information-carrying laser beam, comprising a laser beam generator for emitting a laser beam, a polygonal mirror for directing the laser beam toward a linear zone and deflecting the laser beam to swing repeatedly along the linear zone, roller arrangement for transporting a light-sensitive sheet medium to pass through the linear zone, a sensor for detecting an arrival of the leading edge of the sheet medium at the linear zone, and a control circuit for modulating the laser beam to be generated by the laser beam generator, the control circuit being operative to modulate the laser beam depending on the image to be recorded on a leading portion of a light-sensitive sheet medium before the sensor detects that the leading edge of the sheet medium which has been advancing toward the linear zone reaches the linear zone and to modulate the laser beam depending on the images to be recorded on a portion subsequent to the leading portion of the sheet medium after the sensor detects that the leading edge of the sheet medium advanced toward the linear zone has reached the linear zone.

Laser recorder with sheet edge detection

A laser beam control device related to the present invention includes an optical filter in the path of propagation of the laser beam from a laser light source to an image forming surface to form an image with the laser beam transmitted through the filter, and controls the transmittance of the filter based on the result obtained by detecting the intensity of the transmitted laser beam and comparing the detected value with a value of image density set by an operator.

Optical laser beam control device for printer

A laser recording apparatus for printing multi-tone image data by driving a laser diode according to levels of an analog signal containing the image data thereby to modulate a laser beam output by the laser diode, and causing the modulated laser beam to scan a recording medium in transverse directions. The output of the laser diode is stopped or reduced in level for a certain time in each of periods at predetermined intervals, each period corresponding to each pixel in the printed image. This eliminates mode hopping noise and optical feedback induced intensity noise, and hardly gives rise to the problem of electromagnetic wave disturbance. By elongating or shortening the time for stopping or reducing the emission by the laser diode (which time is shorter than the period corresponding to one pixel), the image density may be adjusted without impairing the above advantage.

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Yamato, Japan

Naoya Misawa