A method of producing a high power and brightness beam from diode laser source that either has a single emitting element or array with a plurality of segments or emitters that are concurrently addressable, or has a plurality of elements or subarrays each having a plurality of laser segments or emitters, which elements or subarrays are independently addressable relative to one another. Beam filling and focusing optics are disposed in front of the emitters so that light from the individual emitters from each subarray converge to from a single overlapping spot. Segmentation of laser subarrays and emitters improves laser life by reducing thermal gradients and isolating any local failures to a single segment emitters, while the focusing of the segments or emitters to overlapping light spots increases the tolerance of the source to local failures. Two or more emitters in a given element must fail before the source is considered to have failed.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional of application Ser. No. 08/269,358, filed Jun. 30, 1994, U.S. Pat. No. 5,594,752, which is a continuation-in-part of application Ser. No. 07/986,207, filed Dec. 7, 1992, U.S. Pat. No. 5,745,153.
A multiple beam light source device includes a plurality of semiconductor laser chips. The plurality of semiconductor laser chips each have respective emission points independent from each other. The plurality of semiconductor laser chips are mounted such that the emission points are located so as to deviate in a direction to approach each other from positions of the centers of the plurality of semiconductor laser chips.
A multimode laser diode stripe is imaged on a light valve, which separates the diode stripe image into a plurality of individually controllable channels. These channels are then imaged onto a recording media where they form a plurality of tracks. Introduction of astigmatism between the multimode laser diode and the light valve causes the laser diode stripe imaged on the light valve to be sharply focussed on its short axis, but less focussed on its elongated axis. This blurring of the stripe's elongated axis at the light valve overcomes near-field non-uniformity in the power distribution of the multimode diode, increasing the reliability and performance of the recording system.
A two dimensional laser diode array consists of rows and columns of individual multimode laser diodes, each diode having a separate collection lens. The array is imaged at a large reduction ratio to achieve high resolution recording. In order to decrease the apparent spacing of the diodes in the scanning direction, the rows are staggered relative to the scan direction. In order to avoid variations caused by the near-field non-uniformity of multimode diodes the final spot generated on the media is an image of the aperture of the collecting lens and not of the diode facet. The larger dimension of this aperture, formed by the diffraction limited direction of the laser diode, is reduced by using anamorphic optics.
There is provided improvement of a light-heat conversion in a light-stimulated writing method. An image recording body includes an element, which absorbs light (electromagnetic wave), provided in a surface of a recording body 10, or in a recording layer formed on uppermost layer of the recording body having a material exhibiting thermal changeable character of wettability, or in a substrate or an intermediate layer of the recording body. After a liquid is on the recording body 10 by a liquid forming means 3, light-stimulated writing is carried out. When the light-stimulated writing is carried out with light (electromagnetic wave) from a light (electromagnetic wave) source according to image information, an efficiency of light-heat conversion can be enhanced by a light (electromagnetic wave)-absorbing element.
A device for recording images on a printing form, including an array of light sources and imaging optics for generating (n.times.m) imaging spots on a printing form, which is distinguished by the array of light sources including an array of mutually independently controllable VCSEL light sources. One specific imaging spot may be formed on the printing form by combining the light emitted by a subarray of the VCSEL light sources. Due to the advantageous beam properties of VCSEL light sources, such as the small divergence and negligible astigmatism, the device for recording images on printing forms is especially advantageous for use in a printing-form imaging unit or in a print unit.
