Abstract:
A process and device are disclosed for synchronising the picking-up of monochrome and colour pictures by means of photosensitive line sensors. A line scanning pattern is generated by a counting device and at the moment when an impulse of the incremental generator is received the timer measures by means of a computer and of the programmable counting arrangement the phase position of the line scanning pattern generated by the counting arrangement, compares said line scanning pattern with an associated calculated or tabled set value and uses the thus obtained phase difference in order to influence the count of a counter connected upstream of the line counter (CT2) (Figures 1 and 2). The time decomposes the measurement lines of the picture pick-up device into two or more scanning lines when the integration time of the photosensitive lines within the measurement line results in an exposure higher than the operating limit of the sensors.
Abstract:
A transport (11) for a laser writing and reading system in which a carriage (15) is propelled by a falling mass, either its own or an auxiliary mass. The falling mass works against a hydraulic cylinder (23) and piston in which hydraulic fluid is displaced from the cylinder. An adjustable valve limits the flow of hydraulic fluid out of the cylinder so that the fall of the mass, and hence the carriage is braked to a uniform velocity. The system also includes a laser (33) having a beam (31) for scanning in a line transverse to the direction of motion of the carriage. A photosensitive medium (18) is disposed to receive the scanning radiation. Either the laser or the photosensitive medium may be mounted on the carriage, with the other mounted in the fixed position in optical communication therewith. A servo system (Fig. 7) receives a signal representing velocity of the carriage and compares it to a first reference signal representing desired carriage velocity. The comparison yields an error signal which is used to adjust the adjustable valve (28) acting as a variable brake for the transport. A second selectable reference signal is provided so that the first reference signal can be bypassed when the carriage is reset at high velocity or is at rest. By controlling the rate of fluid flow through the valve, the mass will fall with uniform velocity, thereby propelling the carriage at a uniform, vibration-free rate.
Abstract:
An optical system, used for scanning, forms an image using reflective optical surfaces. The system may be telecentric, and may form an image that is reduced in size as compared with the scanned original. Several image-forming optical channels may be combined to form a page-wide scanning array.
Abstract:
The invention relates to a device and a method for exposing photosensitive plates (33) for printing presses, comprising controlled laser exposure apparatus and a conveyor system for moving forward the photosensitive plates. The problem with the plate exposers at present is that they are not sufficiently accurate. A device is therefore provided whereby the controlled laser exposure apparatus (63) comprises means (1, 20) for measuring and compensating the variances in the laser beam orientation. The controlled laser exposure apparatus (63) comprises a software control (21). Another problem is that one laser source cannot bridge the scanning of photosensitive plates (200) with great width. Two laser sources (2) synchronised with each other are therefore provided. The invention further relates to a housing for a device such as specified above.
Abstract:
An improved laser pattern generation apparatus. The improved pattern generation apparatus of the present invention uses a laser beam (501) to expose a radiant sensitive film on the workpiece (516) to print circuit patterns on a substrate. The laser beam is aligned using a beam steering means. The laser beam (501) is split into 32 beams to create a brush. The brush scans the workpiece (516) through use of a rotating polygonal mirror (510). Each beam of the brush may have one of seventeen intensity values. The beams are modulated by an Acousto-Optical Modulator (506) signals provided to the Acousto-Optical Modulator (506) define the pattern to be generated. The signals are created by a rasterizer (507) increased print speed is accomplished through the use of a wider brush and a print strategy that eliminates physical stage passes.
Abstract:
A scanning system, having a fixed platen and optical imaging system and a translated reference scale, is provided for scanning of a modulated light beam (or a set of parallel, independently modulated light beams) onto an object surface. The optical system provides a combined light beam including the modulated light beam and a reference light beam. An optical imaging device moves the combined light beam along a scan line, and a translatably mounted beam splitter splits the combined light beam to direct at least some of the reference light beam onto a reference scale and a sensor. The reference scale sensor, which is rigidly attached to the beam splitter, and is responsive to reference beam position in two directions, provides a clocking signal indicative of beam position along the scan line and a vernier position signal indicative of beam position in a direction transverse to the scan line. An optical stepper controls the translation of the beam splitter such as to position precisely each of a series of scans in a direction transverse to the scan lines.
Abstract:
In connection with graphical drum scanning a very high accuracy of the drum is required and the scanner unit has to be very accurately adjusted. The invention provides for different purely dynamic adjustment methods, which enable a significant reduction of the accuracy requirements and therewith a reduced price of the scanner units.
Abstract:
A beam position sensor for a beam scanner is disclosed for use in a laser printer. The printer comprises three diode lasers each of which emits at a different wavelength. The beams from the three lasers are combined by the use of dichroic plates to form one combined beam. The combined beam is scanned onto a receiving medium by a polygon. The beam position sensor of the present invention is adapted to sense the position of the polygon in order to provide a synchronizing signal which will insure that each raster line in the printer is started at the proper position. The beam position sensor includes a diode laser and optics for projecting a beam from the laser onto the polygon. The beam is reflected back from the polygon into a photodetector which effects the start of a new raster line at the appropriate time. In order to minimize the number of optical elements in the beam position sensor and to simplify the device, the diode laser and the photodetector are located along the same optical axis.
Abstract:
A thermal printer is disclosed which is particularly suitable for making slide transparencies. The printer includes a laser which provides the necessary thermal energy to effect a transfer of dye from a donor element to a receiver element. A beam from the laser passes through suitable optics and is scanned onto the receiver element by a galvonometer. In order to insure the transfer of dye from the donor at a suitable resolution and with sufficient speed, a relatively high-powered single transverse mode coherent laser is used.
Abstract:
A beam position sensor for a beam scanner is disclosed for use in a laser printer. The printer comprises three diode lasers each of which emits at a different wavelength. The beams from the three lasers are combined by the use of dichroic plates to form one combined beam. The combined beam is scanned onto a receiving medium by a polygon. The beam position sensor of the present invention is adapted to sense the position of the polygon in order to provide a synchronizing signal which will insure that each raster line in the printer is started at the proper position. The beam position sensor includes a diode laser and optics for projecting a beam from the laser onto the polygon. The beam is reflected back from the polygon into a photodetector which effects the start of a new raster line at the appropriate time.