Chunghwa Picture Tubes, Ltd.

Vanguard International Semiconductor Corporation

Hao-Cheng Hung

Wen-Chi Chen

Chao-Ming Koh

Hua-Sou Tong

Jia-Ching Doong

Hsien-Tzu Chang

Chun-Hung Lu

Yu-Hsin Hu

A method for fabricating Fiber Bragg Grating elements and planar light circuits made thereof. A mask having a predetermined pattern and a wafer are provided, wherein a light-guiding channel filled with light-guiding substance is formed on the wafer. A photoresist layer is then formed to cover the wafer. Magnification of a photolithography apparatus is adjusted to a first Mag., followed by transferring the pattern on the mask to the photoresist layer to form a first pattern. Light-guiding substance not covered by the photoresist layer is then removed so that the first pattern is transferred to the light-guiding channel. The light-guiding channel then forms a Fiber Bragg Grating element.

Method for fabricating Fiber Bragg Grating elements and planar light circuits made thereof

A method for fabricating Fiber Bragg Grating elements and planar light circuits made thereof. A mask having a predetermined pattern and a wafer are provided, wherein a light-guiding channel filled with light-guiding substance is formed on the wafer. A photoresist layer is then formed to cover the wafer. Magnification of a photolithography apparatus is adjusted to a first magnification, followed by transferring the pattern on the mask to the photoresist layer to form a first pattern. Light-guiding substance not covered by the photoresist layer is then removed so that the first pattern is transferred to the light-guiding channel. The light-guiding channel then forms a Fiber Bragg Grating element.

Method for fabricating fiber bragg grating elements and planar light circuits made thereof

An apertured shadow mask in a color cathode ray tube (CRT) serves as a color selection electrode in permitting each of the three electron beams to be incident only upon its associated color-producing phosphor elements on the CRT's display screen. The apertures are arranged in vertical columns and horizontal rows in the shadow mask with aperture spacing defined by a vertical pitch (P.sub.v) i.e., the vertical spacing between adjacent apertures within the same vertical column where the apertures in one row are in different columns than the apertures in adjacent rows, and a horizontal pitch (P.sub.h), i.e., the horizontal spacing between adjacent apertures in the same horizontal row. To increase the color purity adjustment margin particularly in the corners of the display screen while still maintaining sufficient vertical spacing between adjacent phosphor dot color trios for a high degree of video image resolution, P.sub.v is defined in terms of a monotonic decreasing function in the horizontal direction and a monotonic increasing function in the vertical direction as follows:

Shadow mask with improved color purity adjustment margin

A holder for maintaining an apertured shadow mask in fixed relation to the display screen of a color cathode ray tube (CRT) includes the combination of a mounting stud attached to an inner portion of the CRT's glass envelope and an apertured resilient metal holder attached to the shadow mask's peripheral frame and adapted to receive the mounting stud in a tight-fitting manner. A plurality of such mounting stud/metal holder combinations securely attach the top, bottom and lateral edges of the shadow mask frame to adjacent inner portions of the CRT's glass envelope adjacent its display screen. Heating of the shadow mask caused by the CRT's electron beams incident thereon gives rise to heating and thermal expansion of the shadow mask metal holders. Thermal expansion of the metal holders causes the shadow mask to rotate about the CRT's central axis resulting in a shift of the shadow mask apertures with respect to video image-producing phosphor deposits on the display screen's inner surface which degrades video image color purity. To prevent misalignment of the shadow mask apertures with the phosphor deposits caused by shadow mask holder thermal expansion, the shadow mask holders are formed from a material having a low coefficient of thermal expansion which maintains the shadow mask and its apertures in a fixed, predetermined location and orientation during CRT operation. The shadow mask holders are preferably comprised of a material having a coefficient of thermal expansion of less than 2.0.times.10.sup.-6 cm/cm/.degree. C. such as, for example, Invar, Neovar or Kovar.

Thermal expansion for color CRT

An arrangement for mounting a shadow mask, or color selection electrode, in the glass envelope of a color cathode ray tube (CRT) includes four resilient metal holders, each spot welded to a respective upper, lower or lateral portion of the shadow mask's skirt. Each holder is formed from a unitary metal strip which is shaped so as to include an inner mounting portion spot welded to the mask's skirt and an outer apertured portion adapted to receive a stud attached to and extending inwardly from the CRT's glass envelope. The shadow mask undergoes thermal deformation, or doming, when heated by electron beams incident thereon and transfers heat to each of the metallic holders. Each of the metallic holders, in turn, undergoes thermal deformation, but because of the shape and orientation of the holders relative to the shadow mask, the four holders deflect the shadow mask in a direction generally perpendicular to and outward from the CRT's glass display screen, i.e., along the CRT's Z-axis. By deflecting the thermally deformed shadow mask along the CRT's Z-axis, alignment between the mask's beam passing apertures and phosphor deposits on the CRT's display screen is maintained and video image color purity is not degraded.

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Jubei, Taiwan

Hao-Cheng Hung