Abstract: A laser liquid crystal marker and a method of judging deterioration of the liquid crystal make it possible to maintain high printing accuracy, ascertain the proper time for replacement of liquid crystal and, further, maintain high printing accuracy even when high speed printing is continuously performed. The marker has a temperature sensor (4), light emitting means (5), light receiving means (6), and a controller (7). The controller (7) calculates a light transmittance (Qi) from the irradiation quantity of light (R1) of the light emitting means (5) and the transmitted quantity of light (R2) received by the light receiving means (6), and adjusts the applied voltage (Vi) of the liquid crystal (2) so that the light transmittance (Qi) becomes equal to an optimum light transmittance (Qo), stored in advance.

Abstract: A controller for controlling a laser marking machine, which classifies a divided image into a non-printing region (H row) and a printing region ("APPER"). When the non-printing region is displayed on a liquid crystal display screen, the printing pattern ("APPER") is displayed on the liquid crystal screen so that scanning on the liquid crystal display screen is started by a scanning device from the printing region continuing the non-printing region by omitting this non-printing region (H row) when it is in an upper region for which scanning is first made. A moving device corrects the moving distance of the printing position of the printing pattern by the distance corresponding to the non-printing region (H row) so omitted, and starts movement to the marking position of the next divided image (B'3) when scanning of the printing region of this divided image (B'2) is finished.

Abstract: A laser marking system and method with a laser oscillator generating a laser beam that is scanned in a single direction onto a mask (such as a liquid crystal) that displays sequentially a plurality of divided pattern blocks, and a second deflector that deflects the scanned laser beams onto corresponding portions of the surface of a workpiece so as to mark on the surface of the workpiece a combination of the divided pattern blocks . In another embodiment a plurality of masks and a second optical system for combining the beams from the masks can be used to create the mark. The system can be used with a conveyor and a loading and unloading unit using a controller.

Abstract: An image display method for a liquid crystal mask marker displays an image of a high sharpness even when the marking speed is high. To this end, when the display image of a liquid crystal mask (4) is to be rewritten, the method includes performing at least one of (a) making all of the opaque picture elements (B) of the current image (P1) to become transparent, and (b) making all of the transparent picture elements (A) of the current image (P1) to become opaque; then making the electrodes of all of the picture elements (A,B) to be grounded or set equipotentially; and then starting the display of the next image (P2).

Abstract: The invention relates to a laser marking method in which a laser beam is used for raster scanning of a liquid-crystal mask, on which a desired marking pattern is formed and the laser beam passing through the liquid-crystal mask gives a marking to an object. A marking pattern on the liquid-crystal mask is successively switched over to a subsequent marking pattern every scanning line, to reduce variation in transmissivity of the liquid-crystal mask, thereby obtaining marking with less unevenness of image.

Abstract: A method of driving a liquid crystal mask marker increases a marking speed, by reducing the time required for producing an image, and maintains marking accuracy at a high level. For this purpose, a laser beam (L11) is irradiated onto a non-light-permeable portion, such as a non-light-permeable surface and/or a non-liquid-crystal surface, of a liquid crystal mask (8), for example, a liquid crystal electrode member (81), before the liquid crystal mask completes the production of an image when the image is produced on the liquid crystal mask (8).

Abstract: The present invention relates to a transmission type liquid crystal mask marker which can be incorporated easily into a conventional apparatus, and which enables high-speed and high-accuracy stable printing and an increase in the S/N ratio of a sensor output. The transmission type liquid crystal mask marker thus includes a controller for, during rewriting a static marking image displayed on a transmission type liquid crystal mask, displaying a static test image and attaining an equipotential state, and thereafter repeatedly displaying the static marking image and attaining an equipotential state up to the end of the rewriting time, measuring an actual light transmittance of the static test image during rewriting, and regulating the voltage applied to the transmission type liquid crystal mask so that the actual light transmittance is equal to the optimum light transmittance. An optical filter can be provided on a light receiving device for measuring a light transmittance.

Abstract: To implement a high speed scanning, the positions in an image plane in the Y direction ("O") where no primary scanning is to be executed are removed. Only the positions in the Y direction ("1") where primary scanning is to be executed are stored in advance. On the other hand, the position in the Y direction which is currently being primary scanned is detected. Then, based on this result, the next position in the Y direction to be primary scanned ("1") is read from the stored information. The next primary scanning of the position in the Y direction thus read is started as soon as the current primary scanning is complete, thus making it possible to execute the scanning at a higher speed.