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 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: 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: A liquid crystal display for a laser marker for attaining a higher marking speed, characterized in that a liquid crystal display screen (10) is divided into a first zone (10a) where a sub-scanning is first performed and a second zone (10b) where a sub-scanning is performed following the first zone (10a) sub-scanning, that switching of display is performed independently for each of the first and second zones (10a, 10b), and predetermined voltages are applied, respectively, to row and column electrodes after those row and column electrodes are grounded, whereby display switching processing can be performed independently for each of the first and second zones. Completion of the sub-scanning of the first zone (10a) is detected by a position detecting means, and when such a detection is done, switching of display in the first zone (10a) is independently performed.

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: A drive circuit, for use with a transmissive scattered liquid crystal display device, prevents a residual image caused by a high speed display switching, while having a reduced size and fewer parts, thereby improving reliability. The drive circuit comprises a shift register (3a), a first gate for functioning as an AND circuit (2a), a second gate for functioning as an exclusive OR circuit (2b), and a switching device (7) with a higher withstand voltage than a logic signal. These constructional elements are formed within an IC. A logic signal for driving the liquid crystal display device is input to the second gate (2b). The output of the buffer (8) is connected to a totem pole drive circuit (10) for driving a common electrode (C) with a high voltage (HV) which is synchronized with the logic signal.

Abstract: A YAG laser mask marker includes a YAG laser oscillator (1), a first deflector (3X, 3Y) for deflecting a laser beam from the YAG laser oscillator in X and Y directions, a liquid crystal mask (6) for displaying a predetermined pattern to be raster scanned by the laser beam from the first deflector, a second deflector (7X, 7Y) for deflecting in X and Y directions the raster scanned light which has passed through the liquid crystal mask, a work (10) on which the raster scanned light from the second deflector is illuminated to print the pattern on an surface thereof, and a controller (11).