Anti-Glare device for a computer terminal display tube

An anti-glare device for the display tube of a computer terminal or other video display tube wherein illuminated messages or images are presented on a highly reflective surface, comprising a microweave screen of fine black filaments in a fine mesh mounted in a flexible frame so that the screen conforms to and maintains contact with, the display tube. The frame is secured so that the screen covers the terminal tube, and substantially conforms to the surface thereof. The filaments are preferably approximately 0.0025 inch in diameter and there are approximately 150 filaments per inch.

BACKGROUND OF THE INVENTION 
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. 
OBJECT OF THE INVENTION 
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. 
SUMMARY OF THE INVENTION 
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.

DESCRIPTION OF A PREFERRED EMBODIMENT 
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.