Improvements in Instruments for Estimating, Measuring, or Com- paring Color, Texture, and Appearance of Transparent or Opaque Bodies, and for Testing Color Vision and Light Perceptive Power.
Year: 1890

page_text: Date of Application, 23rd Apr., 1890
Complete Specification Left, 23rd Jan., 1891-Accepted, 7th Mar., 1891
PROVISIONAL SPECIFICATION.
Improvements in Instruments for Estimating, Measuring, or Com-
paring Color, Texture, and Appearance of Transparent or Opaque
Bodies, and for Testing Color Vision and Light Perceptive
Power.
I, JOSEPH WILLIAMS LOVIBOND, of 26, St. Ann Street, Salisbury, in the
County of Wilts, Brewer, Maltster, and Wine and Spirit Merchant, do hereby
declare the nature of this invention to be as follows:-
My invention relates to improvements in the "tintometer or instrument for
estimating, measuring, or comparing color, texture, and appearance of transparent
or opaque bodies, whether solid or liquid, for which two previous Letters Patent
were granted to me dated respectively October 9th, 1886, No. 12,867, and
March 14th 1887 No. 3859.
My present improvements have first for their object to improve the instrument
for the purpose for which it was originally designed by rendering the said instrument
binocular and so afford a better vision of the object under examination without
however introducing any liability to error arising from difference of color vision of
the two eyes of the observer. It has for its object, secondly, to render the instru-
ment available for the purpose of testing color vision and light perceptive power
generally, whether of one or both eyes.
For the purposes of my present invention, the instrument is provided with two
eye pieces, each of which would command the same field of view when used for the
purposes of a "tintometer," such field comprising say two three or more apertures
at the opposite end of the instrument adapted, the one to receive the sample or
object under observation, and the other or others the standard tints with which it
is to be compared or vice versa.
For the purpose of testing color vision the instrument is provided with a central
removable division which when placed in position separates the field of view into
two parts-respectively corresponding to the two eye pieces. The central aperture
may be closed and the fields of view would then be distinct, each comprising an
aperture wherein standard tints are adjusted as before for purposes of comparison,
for ascertaining and measuring difference of color vision and light perceptive power
as between the one eye and the other, or defective color vision and perceptive power
of both eyes.
Dated this 23rd day of April 1890.
COMPLETE
SPECIFICATION.
Improvements in Instruments for Estimating, Measuring, or Com-
paring Color, Texture, and Appearance of Transparent or Opaque
Bodies, and for Testing Color vision and Light Perceptive
Power.
-
I, JOSEPH WILLIAMS LOVIBOND, of 26, St. Ann Street, Salisbury, in the
County of Wilts, Brewer, Maltster, and Wine and Spirit Merchant, do hereby
declare the nature of this invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
My invention relates to improvements in the "tintometer" or optical instrument
for use in the examination of translucent matter for color-intensity and of opaque
matter for superficial color structure or texture, for which previous Letters Patent
Price 8d

page_text: were granted to me dated respectively October 9th 1886, No. 12867, and
March 14th 1887, No. 3859.
Such instrument is monocular, and my present improvements consist, first, in
making the said instrument binocular so as to afford a better view of the matter
under examination and of the standard to which it is referred, secondly, to render
the instrument available for the purpose of testing color-vision and light perceptive
power of the human eye.
for the
The instrument is provided with two eye-pieces or apertures, both commanding
the same field of view when used for the purposes of a "tintometer
measurement of color-intensity and the like, the said apertures being of such form
that no lateral adjustment is required in order to suit different distances between
the eyes of different observers. The instrument is readily convertible to the purposes
of a color-vision and light perceptive power tester, by the insertion of a removable
division by which the two eye-pieces are made to command separate fields of view
which may either be wholly distinct or partly distinct and partly common to both
eye-pieces, as may be required for ascertaining and measuring defective color-vision
and light perceptive power (or difference of color-vision and light perceptive power)
as between the one eye and the other.
Reference is to be had to the accompanying drawings, forming part of this
Specification wherein
Figure 1 is a horizontal section, Figure 2 a longitudinal vertical section, on
line - Figure 1, and Figure 3 an end view, of the instrument.
Figures 4 and 5 are details.
Similar letters of reference denote like parts in all the figures.
Referring to Figures 1 and 2, which illustrate the instrument as used for the
purposes of a tintometer," A is the body of the instrument in the form of a tube
of oblong cross-section having one end concavely curved as at B the said end being
closed but having the eye slits therein, the said slits being horizontal and of just
sufficient width to admit of a clear view through the instrument when the eyes are
applied as close as possible thereto, the length and distance apart of the slits being
such as to suit the different distances between the eyes of different observers,
without requiring the lateral adjustment usual in binocular instruments. There is
also a central aperture 1, through which a view of both fields may be had by one
eye either with or without a prism for bringing the image of the two fields in close
proximity so that the instrument may be used monocularly or binocularly at will.
The concave form of this end of the instrument enables the eyes of the observer
to be placed close to the apertures and shields the eyes from extraneous light, but
it will be obvious that this end of the instrument might be plane and ordinary lateral
shields be provided for excluding side light. The other end or field of the instrument
is adapted to be divided into two or more apertures at which to view the sample to
be examined and the standard with which it is to be compared, the said standard
being, as before, any multiple of a unit of color-intensity of known value. The
sample, if fluid, would be contained in a gauged bottle by which the thickness of
the stratum traversed by the beam of light is known, this bottle being placed in
the optical axis of one eye aperture band the standard unit tints and multiples
thereof are placed in the optical axis of the other eye aperture. The respective.
positions occupied by the sample and standards may be denoted by the letters C D.
Between the sample and standards is a central removable grooved rack c corre-
sponding to the grooved extensions of the side walls of the tube A, the grooves
serving to receive the slides which constitute the standard tints.
A diaphragm d (shewn separately in perspective view in Figure 4) having two
apertures e e is fitted in the field of the instrument, and this diaphragm might be
permanently combined with the rack c, as shewn in Figure 4, so as to be removable
together. To prevent oblique rays, transmitted or refracted through the sample
and standard, being reflected to the eyes of the observer, stops, formed by inwardly-
projecting ribs f, are fixed around the sides of the body A at intervals in its
length.

page_text: When used for the purposes of a "tintometer," the whole field of view, containing
the sample and standards, is commanded by both eyes of the observer, but, to adapt
the above described instrument to the purpose of testing color-vision and light
perceptive power, a longitudinal central partition g is inserted in grooves g' in the
body A of the instrument whereby the latter is divided into two parallel tubes
respectively corresponding to the two eye-apertures bb. When this partition is
inserted, the diaphragm d is replaced by another one d (shewn separately in
perspective view in Figure 5) having three (or more) apertures e' with intervening
racks c'e' to hold the objects and standards opposite the respective apertures of the
diaphragm. The central aperture e' is divided diametrically by the partition y so
that the field visible to each eye, comprises one half of the said central aperture
and the aperture (or apertures) to the right or left thereof, as the case may be.
Opposite the central aperture is placed the substance to be compared with the
standards of color placed opposite the lateral apertures.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described "tintometer or instrument for ascertaining the color-
intensity of translucent matter, consisting of a single tube having at the optical end
two sight-apertures and at the object end two apertures both commanded by each
sight aperture and adapted to respectively receive the subject under examination,
and a series of standard tints for comparison therewith, substantially as specified.
2. The herein described instrument having the optical end of concave form with
horizontal slits for binocular and monocular vision, substantially as specified.
3. The combination, with the herein-described instrument, of the removable
diaphragm at the object end for permitting the transmission of separate beams of
light through the matter under examination and through the standards, as
described.
4. The combination, with the herein-described instrument, of the removable
longitudinal central partition dividing the body of the instrument into two distinct
tubes, and of a removable diaphragm at the object end having three or more
apertures of which the central one is diametrically divided by the partition so as to
be partly visible through cach tube, whilst the others are only visible through
different tubes, substantially as specified.
Dated this 23rd day of January 1891
J. W. LOVIBOND.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.