Computer graphics processing and selective visual display system – Plural physical display element control system – Display elements arranged in matrix
Reexamination Certificate
2000-08-14
2002-06-11
Saras, Steven (Department: 2675)
Computer graphics processing and selective visual display system
Plural physical display element control system
Display elements arranged in matrix
C345S108000, C359S230000
Reexamination Certificate
active
06404413
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an electrostatic display device and more particularly a chromatophore display mechanism, improved display control circuitry and cost effective methods for display production.
2. Discussion of Prior Art
Display devices based upon electrostatic attraction of a thin, insulated dielectric membrane have been disclosed in a number of prior art patents including: U.S. Pat. Nos. 3,897,997; 4,094,590; 4,105,294; 4,160,582; 4,229,075; 4,336,536; 4,468,663; 4,747,670; 4,831,371; 4,891,635; and 5,667,784. Generally these prior art devices require fabrication by assembling small mechanical parts, the very nature of which precludes cost-effective production of displays having the number of pixels typical of many display applications.
This invention bears a relation to three prior inventions by one of the inventors, Ellis D. Harris. U.S. Pat. No. 6,081,249 “WRAP AROUND MEMBRANE COLOR DISPLAY DEVICE” describes an assembly of filament electrodes, membrane sandwiches and silicon electronics to achieve a chromatophore color display. A second patent U.S. Pat. No. 6,127,725 ‘THIN INSULATOR ON METAL’, describes patches of silicon-on-insulator-on foil has been allowed by the U.S. Patent Office and its issue is pending. The present inventive display device utilizes features of these two inventions. The third patent bearing relation to the current disclosure is U.S. Pat. No. 6,198,512 ‘METHOD FOR COLOR IN CHROMATOPHORE DISPLAYS’ and describes means to transform television color signal into a form useful in a chromatophore display including a display of the type of the present invention. These above three patents are included herein by reference.
Chromatophore is the term used to designate selectable pigment elements to provide color selectivity with only ambient illumination. The classical example is the color variation in certain animals, notably a chameleon, wherein changes of color are effected by means of pigment-bearing sacs. By analogy a chromatophoric display is defined as a display wherein non self-luminous picture elements change color under electronic control and are viewable under ambient illumination.
A first primary benefit of a chromatophoric display is that the amount of power consumed is many times less than that required by current display technologies. This is especially significant for portable display devices wherein power must be supplied by a battery pack. The lower power consumption is the result of three inherent technical advantages of chromatophoric displays: 1) No power is required for transmissive illumination; 2) Each pixel does not require constant drive power to show a desired color—drive power is only consumed in the instant when the color is changed; and 3) Only a fraction of the pixels are consuming drive power at any given time. An example of the last benefit would be a display used for a word processor where the only pixels requiring power are those forming the new letters as they are entered on the keyboard while the rest of the pixels remain unchanged.
A second primary benefit is that the display is viewable under very bright conditions, such as direct sunlight. The utilization of CRT, LCD or other self-luminous displays is often disappointing in bright ambient light environments because there is insufficient transmissive display illumination to create enough contrast for easy viewing. By comparison, an outdoor sign such as a billboard is highly visible in bright sunlight. A chromatophoric display combines aspects of a painting hanging on a wall or an outdoor sign viewed in reflected light with the moving features of cinema or television. Like a picture on a wall it utilizes and requires ambient illumination for viewing. Although low ambient illumination conditions may require auxiliary illumination, such auxiliary illumination need not be generated by the display itself Supplying such illumination by external means will be cost-effective relative to supplying the power needs of a self-luminous display.
A third primary benefit is that the display can be made very thin, light and flexible for many applications not possible with display technologies requiring rigid glass components.
A fourth primary benefit of chromatophoric displays is the absence of flicker which is known to induce psychosomatic distress in some individuals. Flicker is common in displays that rely on a phosphor since the phosphor for any given pixel is stimulated only once for each frame and the luminosity decays over the rest of the frame. In cinema, flicker results from the limited fraction of time that the film gate is open during a frame time. A cinema frame is mostly all on when the film gate is open and mostly all off when the film gate is closed. By contrast in a chromatophoric display, once a chromatophore color is set it remains constant and unchanged until the image requirements require a different color. Pixel brightness of a chromatophoric display does not decay during the frame time as in the case of the phosphor on a CRT display. At no time is the frame completely Black, as is the case between frames in cinema. As a consequence there is no perceivable flicker in a chromatophoric display.
A fifth primary benefit of a chromatophoric display is the ability to easily retain images. Since the flexible membrane of a chromatophore element will still retain its position when the drive signal is removed, this enables the inventive display device to hold an image for a period of time after disconnection from electronic display drivers. Display retention can be extended indefinitely with the inclusion of holding electronics including a minimum battery voltage supply. The retained display may later be recovered by connecting the display to source of electric power and synchronization.
The present inventive display device describes an innovative chromatophore geometry that makes it possible to produce high resolution displays in high volumes and cost effectively. The chromatophore geometry, display control circuitry and production methodology are applicable for both monochrome and color devices—Beneficial features are inherent in both. Innovative display technologies have invariably developed first in monochromatic form and color technology has subsequently followed. When color has been available it has been preferred, both for esthetics and for the additional information that can be conveyed.
Where self-luminous displays are commonly characterized in terms of luminosity, chromatophoric displays must be characterized in terms of brightness. For the presentation of color images the inventive chromatophoric display device has the inherent capability for all pixels in any localized area to be any of the bright primary colors, Cyan, Magenta, and Yellow. This capability allows the display of highlight colors in maximum brightness. The darker primary colors of Red, Green and Blue may also be made available along with Black and White. With these eight colors many hues and chromas can be made available and human perception of color in a chromatophoric display can approximate the color resolution used extensively in multicolor printed images today.
Coloring of the chromatophores can be accomplished using ink and pigment technologies in various forms that are well known and in an advanced state of development. Pigment particle size can average 0.04 microns, with often a maximum of 0.2 microns. Colored transmissivity is optimum for the smaller particle sizes. A well-known approach to enhance color is to include fluorescence in the pigment formulation. In a typical approach a fluorescing dye is included that absorbs light in the UV and produces a fluorescence that adds to the passive pigment color.
A display device can be formed using an array of chromatophore mechanisms or elements. An array is commonly perceived in terms of rows and columns. For purposes of this present invention a more general definition is used wherein an array is considered as a grouping of elements in a general sense, including rectangular, hexagonal, circ
Harris Ellis D.
Stratford Scott M.
Bell Paul
Saras Steven
LandOfFree
Electrostatic chromatophoric display does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electrostatic chromatophoric display, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrostatic chromatophoric display will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2942523