Representation of color for blind persons

The convention is established and made known to a blind person that a first set of substantially parallel first lines oriented on a substrate in a first direction represents a first color, a second set of substantially parallel second lines oriented on the substrate in a second direction represents a second color and a third set of substantially parallel third lines oriented on the substrate in a third direction represents a third color. The three colors are different from each other and, when mixed together in different combinations, provide other different colors. The three colors may be magenta, cyan and yellow from which green, purple and red can be derived by various combinations of two of the three basic colors and black from all three. The three directions are different from each other, e.g., horizontal, 60.degree. and 120.degree.. In the area of the substrate where color is to be represented, one or more of the three sets of lines oriented in its or their respective direction or directions is or are provided depending on the color to be represented, these lines being constructed and arranged to be capable of being sensed by the fingers of a blind person.

BACKGROUND OF THE INVENTION 
The braille system has been in use since about 1829 and enables blind 
persons to touch read and write. The braille code consists of six dots 
numbered from one to six in a group known as a braille cell. By 
convention, each letter of the alphabet has a different number pattern of 
dots. Likewise numbers and punctuation are represented in braille code. 
The printing of braille is accomplished by impressing dots in paper using a 
mechanical typewriter. Duplication of braille print is slow and expensive 
involving the creation and use of an embossing aluminum master which is 
employed to impress braille characters in paper. 
While braille is suitable for representing letters, numbers and 
punctuation, the inventor is not aware of any suitable technique ever 
having been developed for conveying color recognition to a blind person. 
Of course, persons who have been blind since birth have no appreciation for 
or understanding of color, but this is not the case with respect to 
persons who became blind later in life. 
Color is an important factor in communication among sighted people. It is 
used, for example, to present maps, engineering drawings, statistics, 
geometrical figures and many other types of information, and it would be 
desirable to provide the blind with a system for color recognition. 
An object of an aspect of this invention is to provide a color recognition 
system for blind persons. 
An object of an aspect of this invention is to provide a color recognition 
system for blind persons which can be effected using modern equipment, 
such as a xerographic black and white or color copier, but which also can 
be effected by embossing or other techniques, if desired. 
SUMMARY OF THE INVENTION 
Various aspects of the invention are as follows: 
For use in representing color to a blind person, the provision on a 
substrate in superimposed relationship to each other of at least two sets 
of a first set of substantially parallel first lines, a second set of 
substantially parallel second lines and third set of substantially 
parallel third lines, the orientation of said first, second and third sets 
on said substrate by convention known to the blind person representing 
three different colors which, when mixed together in different 
combinations, provide other different colors, said first, second and third 
sets of lines extending in three different directions with respect to each 
other, said lines being capable of being sensed by the fingers of the 
blind person. 
A method for representing color to a blind person in which a convention has 
been established and is known to the blind person that a first set of 
substantially parallel first lines oriented on a substrate in a first 
direction represents a first color, a second set of substantially parallel 
second lines oriented on said substrate in a second direction represents a 
second color and a third set of substantially parallel third lines 
oriented on said substrate in a third direction represents a third color; 
said first, second and third colors being different from each other and, 
when mixed together in different combinations, providing other different 
colors; said first, second and third directions being different from each 
other; comprising providing on said substrate in superimposed relationship 
to each other and in an area where color is to be represented at least two 
sets of said first, second and third sets of lines oriented in their 
respective directions and constructed and arranged to be capable of being 
sensed by the fingers of the blind person. 
A method for representing color to a blind person in which a convention has 
been established and is known to the blind person that a first set of 
substantially parallel first lines oriented on a substrate in a first 
direction represents a first color, a second set of substantially parallel 
second lines oriented on said substrate in a second direction represents a 
second color and a third set of substantially parallel third lines 
oriented on said substrate in a third direction represents a third color; 
said first, second and third colors being different from each other and, 
when mixed together in different combinations, providing other different 
colors; said first, second and third directions being different from each 
other; comprising providing on said substrate in an area where color is to 
be represented said first, second and third sets on lines oriented in 
their respective directions and constructed and arranged to be capable of 
being sensed by the fingers of the blind person, said first, second and 
third sets of lines being provided on said substrate by selectively 
exposing three times to light an original to be copied on said substrate, 
once using a filter for said first color and a screen having said first 
lines to produce a first image, a second time using a filter for said 
second color and a screen having said second lines to produce a second 
image and a third time using a filter for said third color and a screen 
having said third lines to produce a third image.

Referring first to FIG. 1, which illustrates the essence of this invention, 
it is well known that a number of different colors can be created by 
mixing various combinations of three primary colors. For example, any 
color can be represented by mixing the three primary colors magenta, cyan 
and yellow, the hue of the desired color depending on the relative 
proportion of the three primary colors. 
In accordance with an aspect of this invention, each primary color is 
represented by a set of parallel lines, and the various sets are oriented 
at different angles to each other. Thus, and strictly by way of example, 
there is shown a substrate 10 in FIG. 1, e.g., a piece of paper, on which 
there is a first set of horizontal lines 11 that represents magenta, a 
second set of lines 12 that represents cyan and a third set of lines 13 
that represents yellow. This convention is established and is made known 
to blind persons, i.e., that horizontal lines 11 represent magenta, 
inclined lines 12 represent cyan and inclined lines 13 represent yellow. 
The orientation of the three sets of lines is different, so that their 
direction can be sensed by touch, and, to this end, and as shown in FIG. 
2, the lines are raised above substrate 10, as will be discussed herein 
later. 
Strictly by way of example, although in the preferred embodiment, lines 12 
are at 60.degree. to the horizontal (lines 11) and lines 13 are at 
120.degree. to the horizontal. Other angles could be employed, but 
0.degree., 60.degree. and 120.degree. gives the greatest angular 
separation between the lines when they are put together and, hence, 
facilitates determination by touch as to which lines are present when two 
or more of the sets of lines 11, 12 and 13 are used. 
Cyan and magenta combine to form purple, and thus purple is represented on 
the "color" chart at 14 by sets of lines 11 and 12. Likewise green is 
represented on the "color" chart at 15 by sets of lines 12 and 13 (cyan 
and yellow) and red is represented on the "color" chart at 16 by sets of 
lines 11 and 13 (magenta and yellow). Black is formed by magenta, cyan and 
yellow and thus is represented on the "color" chart at 17 by sets of lines 
11, 12 and 13. 
As previously noted, the lines are such as to be capable of being sensed by 
the fingers of a blind person, and the appropriate lines are placed on 
substrate 10 in an area where color is to be represented such that when a 
blind person who knows of the convention that has been established feels 
the lines, that person can determine from the orientation of the lines 
whether magenta, purple, cyan, green, yellow, red or black is being 
represented. 
The lines 11, 12 and 13 all may be of any desired color or colors. For 
example, they all may be black and may be formed of the black toner of a 
black and white copier. On the other hand, if the "color" chart of FIG. 1 
is produced in a color copier, lines 11, 12 and 13 may be magenta, cyan 
and yellow respectively, such that, to a sighted person, these respective 
colors will appear at areas 11a, 12a and 13a respectively in FIG. 1, while 
the colors purple, green, red and black will appear to a sighted person at 
areas 14, 15, 16 and 17 respectively. 
Many techniques may be employed for creating lines 11, 12 and 13. For 
example, they may be embossed in a paper substrate in the same manner in 
which braille printing has been accomplished for years. This would be a 
laborious, expensive and time-consuming technique, however, and thus is 
not the preferred technique. 
A preferred technique involves the use of screens or masks to give the 
various sets of lines 11, 12 and 13 and color separation techniques. 
Referring to FIGS. 3A-3C there are shown three screens or masks 18, 19 and 
20 that are lined to represent magenta, cyan and yellow respectively. 
These screens are simple transparencies on which opaque, white lines 11a, 
12a and 13a corresponding to lines 11, 12 and 13 respectively are 
provided, e.g., by a normal printing operation. 
If a color original is exposed to white light, and the reflected light from 
the original is passed through a red filter, only the cyan component, if 
any, of the original, will pass through the red filter. Likewise, by 
employing green and blue filters the magenta and yellow components, if 
any, of the original, can be obtained. If, in conjunction with the red, 
green and blue filters, the reflected light is passed through screens 19, 
18 and 20, the result will be the obtaining of the magenta, cyan and 
yellow components of the original represented by lines 11, 12 and 13 
respectively derived from screens 18, 19 and 20 respectively. 
Referring to FIG. 4, one specific technique for creating colors for 
recognition by the blind is shown. In FIG. 4 a color copier of the 
xerographic type is schematically illustrated. Such copiers are well known 
and will not be described in detail. However, the copier includes a 
rotatable, photoreceptor drum (or belt) 21; a charging station 22 at which 
drum 21 may be appropriately electrically charged, e.g., by means of a 
corotron; an imaging station 23 at which an electrostatic image of the 
original (shown at 24 on a platen 25) may be created on a drum 21 by an 
optical system involving a movable lens 27 and red, green and blue filters 
(not shown but associated with lens 27); a developing station 28 at which 
magenta, cyan and yellow toners can be selectively and sequentially 
applied to develop the latent electrostatic image on drum 21; a transfer 
station 29 at which the developed image can be transferred from drum 21 to 
a suitable substrate, e.g., paper; and a fuser station 30 at which the 
magenta, cyan and yellow toners are simultaneously fused. 
The conventional color copier of FIG. 4 is modified, as shown in that 
Figure, and in FIGS. 5A-5E, by the inclusion between light source 26 and 
platen 25 of a movable belt 31 driven by any suitable means, e.g., a 
stepping motor (not shown), that has on it or is constituted by screens 
18-20 (FIGS. 3A-3C) mounted side-by-side. 
Referring now to FIG. 5, the steps for creating an image of the cyan 
component of original 24 will be described. 
As shown in FIG. 5A, belt 31 is moved to remove screen 18 (the pattern for 
magenta) from beneath platen 25 and place screen 19 (the pattern for cyan) 
under platen 25 (FIG. 5B). Original 24 then is exposed to light from light 
source 26 through screen 19 and the reflected light is passed through a 
red filter 32 that is associated with lens 27. Light source 26, lens 27 
and filter 32 all are moved in synchronism, and the complete original is 
scanned. This creates an image on photoreceptor 21 that is lined like 
screen 19 and which is developed using cyan toner. 
In the same manner the magenta and yellow components of the original can be 
reproduced using screens 18 and 20 (not shown) on or of belt 31 and green 
and blue filters (not shown) associated with lens 27, the magenta and 
yellow toners respectively being employed to develop the latent 
electrostatic images. In other words, the original is exposed three times 
using the red, green and blue filters and screens 19, 18 and 20 
respectively, the three images are developed using cyan, magenta and 
yellow toners respectively, and the transferred toner image on the 
transfer paper than is fused in fuser 30. 
Of course, if it is not desired or necessary to produce a color 
reproduction of the original black toners can be used at developing 
station 28 in place of the magenta, cyan and yellow toners. 
An ordinary black and white xerographic copier also may be used for 
creating a color pattern recognizable to a blind person. Such a copier 
would have to be modified by the use of a belt such as 31 having 
superimposed thereon red, green and blue filters in registry with screens 
19, 18 and 20 respectively, and by the use of a stronger light source 
similar to that used in color copiers. The original then would have to be 
exposed three times through the different filter/screen combinations and 
processed through the copier each time. Provided that proper attention is 
paid to registration, this will effectively superimpose the three images 
on the copy. 
Lines 11, 12 and 13 (FIG. 1) must be capable of being sensed by the fingers 
of a blind person. One way to achieve this objective is to employ 
expandable toners which, as such, are known in the art. These toners, when 
fused, swell up, and the amounts thereof that are deposited can be 
regulated taking their degree of expansion into consideration to produce 
"raised" lines of appropriate depth to be capable of being sensed by a 
blind person. Where expandable toners are used, the hue of the color being 
reproduced by lines 11, 12 and 13 will be proportionate to the depth and 
thickness of the lines. For example, colors between magenta and red will 
be represented by lines 11 and 13 with lines 11 being of progressively 
less depth and thickness going toward red and lines 13 being of even less 
depth and thickness between red and magenta, lines 11 and 13 being of 
equal depth and thickness when red is being portrayed. 
Alternatively, known expandable papers (the substrate) can be used. In this 
case the copy is made using, preferably, black toner on a paper which has 
been coated with light-sensitive microcapsules. Developing is achieved by 
exposing the copy to long wavelength light which heats the microcapsules 
under the toner to a greater extent than elsewhere, because of the greater 
tendency of the black toner to heat, causing the microcapsules under the 
toner to expand and producing the required raised relief. 
While the instant invention can be used to reproduce any color original, 
obviously it will be difficult to produce a meaningful copy of an original 
having in a small area many changes of hues and/or colors. The invention 
is particularly useful, however, in cases where large areas or blocks of 
solid colors are to be reproduced. 
While preferred embodiments have been described and illustrated herein, the 
person skilled in the art will appreciate that changes and modifications 
may be made therein without departing from the spirit and scope of this 
invention as defined in the appended claims.