Anti-Glare Device for a Computer Terminal Display Tube

There is an ever expanding use of computer terminals and other video display screens or tubes wherein a message or image is displayed in illuminated numbers and words. Typically, a keyboard operator punches out the date input, and the message so input, as well as the output retrieved from the computer are flashed on a screen which is normally of glass or other highly reflective material. Experience has shown that there are many instances of eye fatigue and worker inefficiency resulting from reading the messages displayed on highly reflective surfaces for extended periods. Various filters and screens have been tried in order to eliminate the glare but such screens carried in a rigid frame spaced from the display tube produce distorations in Newton rings and Moires.

It is an object of this invention to provide a device for eliminating the glare from the surface of a computer terminal display tube or other video viewer without interferring with the reception of the illuminated display.

It is a further object of this invention to facilitate extended human viewing of a computer terminal display.

Other objects and advantages of this invention will become apparent from the description to follow, particularly when read in conjunction with the accompanying drawings.

In carrying out this invention, I provide a screen of microweave mesh of black filaments of Nylon or the like, and mount the screen in a flexible frame adapted to be mounted directly on the front of a terminal display tube to conform substantially to the surface thereof. The filaments are approximately 0.0025 inch in diameter and there are approximately 150 filaments per inch, providing mesh openings approximately 0.005 inch. Means are provided on the frame for attaching the screen to cover the surface of the terminal tube so that even light which passes through the mesh openings is absorbed by the black filaments when reflected back from the surface of the tube. The screen maintains contact over the surface of the tube to eliminate Newton rings and Moires.

In the drawing:

FIG. 1 is a perspective view of the keyboard display terminal showing my anti-glare device;

FIG. 2 is a partial section view taken through the screen and the surface of the display tube; and

FIG. 3 is a partial view in perspective of the anti-glare screen and frame.

Referring now to FIG. 1 with greater particularity, there is shown a computer terminal 10 having a tube 12 on which a message 14 is presented in illuminated numbers, symbols and letters representing an input and/or feedback in accordance with operation of standard keys 16 at a keyboard 17, In typical operation, an operator is positioned in front of the highly reflective display screen or tube 12 having a surface of glass or the like and punches in input signals at the keyboard 16 which are read on a screen 12 and then translated by the computer 10 to a message 14 to be read by the operator. Because of the highly reflective surface of the scope 12, sunlight, room lighting and the like presents a glare from the tube surface which lessons the contrast between symbols and background 12. This often results in eyestrain, impairing the efficiency of the operator and making it difficult to work at the keyboard 16 for extended periods.

In carrying out this invention, I provide a screen of a micro woven material such as Nylon which has been dyed black to render it more light absorbent. The screening 18 is of very fine filaments woven in close mesh and mounted in an opaque frame 20 of a relatively rigid material such as a suitable plastic. The filaments in the screen 18 are substantially less than 0.01 inch diameter and preferably around 0.0025 inch in diameter, with more than 75 and preferably approximately 150 filaments per inch.

The frame 18 is adhered around the face of the tube 12 and, being of a flexible material, such as a suitable plastic, conforms to and contacts, the curved surface of the tube so that the distortion caused by the mingling of shadows cast by the filaments of the microweave screen 18 which otherwise may produce Newton rings and Moire patterns, is eliminated. The screen 18 may be secured to cover the tube 12 by clamping it thereto under the front panel or bezel, or it may be secured to the tube by means of a strip 24 of an adhesive material carried on the flexible frame, with the screen 18 maintaining contact with the tube 12, as shown in FIG. 2.

As indicated by the arrows in FIG. 2, virtually the only external light which is reflected back to the operator's eye is that which is normal or nearly normal to the tube 12. Any light rays approaching from an angle are absorbed directly, or upon reflection by the black Nylon filaments 18a of the screen 18.

With 150 filaments per inch, each 0.0025 inches in diameter, 371/2 of each lineal inch across the screen is occupied by filaments, themselves very closely spaces in fine mesh to present a very effective barrier against transmission of direct and reflected light. This greatly reduces glare to virtually nil, correspondingly increasing operator comfort and efficiency.

A screen material 18 satisfactory for purposes of this invention is a monofilament Nylon screen particularly adapted for fluid screening and filtering.

While this invention has been described in conjunction with a preferred embodiment thereof, it is obvious that modifications and changes therein may be made by those skilled in the art without departing from the spirit and scope of this invention, as defined by the claims appended hereto.