Abstract: An electro-acoustical transducer device is disclosed, which includes: a hollow disk body that generally defines an axis of propagation, the hollow disk body comprising: a pair of plate members extending substantially perpendicular to the axis of propagation, each provided with a central transmitting port arranged about the axis of propagation, and a peripheral enclosure jointing the pair of plate members at the respective outer edge portions thereof, thereby defining a chamber of resonance between the pair of plate members; wherein a ring-opening about the axis of propagation that enables access to the chamber of resonance is formed between the central transmitting ports of the plate members.

Abstract: A method of manufacturing a color filter for a reflective liquid crystal display is disclosed. The method comprises the following steps: 1) coating a layer of positive photoresist on a reflective layer or reflective substrate, and exposing the photoresist layer to a light via a mask having a fine pixel pattern so as to form at least three exposed regions of different exposed energy in the photoresist layer, 2) Removing one of the existing exposed regions having a largest exposed dose by the use of an alkaline developer solution so as to expose the surface of the electrically conductive reflective substrate corresponding to the removed region; and electrodepositing a color paint on the exposed surface of the reflective substrate to form a color filter layer of one selected color, 3) repeating step 2) to remove the other exposed regions in the photoresist layer and proceeding with an electrodeposition process with another color paint until a color filter layer of all desired colors is completed.

Abstract: The invention discloses a liquid crystal panel which is characterized in that each color filter is compartmentalized by the black matrix and the spacers are positioned on the region confined by the black matrix and the spacer bottom connects the first conductive film. The invention also discloses a process for producing liquid crystal panel, which is characterized in that the color filters and spacers are produced by coating a four-level photoresist and by a first exposure step which is masked by a four-level photoresist; the red region, green region and blue region are produced by development and electro-deposition; and the spacers are produced by a second exposure step which is masked by a spacer reticle, a development step which emerges the first conductive film within a region confined by the black matrix, and a step of electrodeposition coating compositions on the emerged region of the first conductive film.