An Improved Screen for Optical Projection Purposes.
Year: 1896

page_text: Date of Application, 25th Sept., 1896-Accepted, 31st Oct., 1896
COMPLETE SPECIFICATION.
An Improved Screen for Optical Projection Purposes.
We LEWIS WRIGHT of 52 Cromwell Avenue Highgate London N. Publishers'
Editor and JOHN ANDERTON of 142 Suffolk Street Birmingham Scientific
Instrument Maker, 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 :-
Hitherto metallic faced screens for optical projection purposes have been made
with a plain surface and as a result the superior brightness possessed by them over
screens of other kinds has been apparent only within a somewhat limited angle of
view; also portable screens used for optical projection that are faced with paper
metallic foil or other material are liable to buckle and curl at the edges, and by so
doing destroy the evenness of the surface.
By our present invention we overcome these defects in the screens for use with
magic or optical lanterns, lantern-microscopes and all other optical projection and
reflecting apparatus and our improved method of arrangement consists firstly in
applying to calico, linen, canvas, or other suitable material or substance forming
the screens or covering of the same, or to wall surfaces or other situations as
required, a facing or surface composed of silver or other metal or metallic sheets,
films, or leaves, or powdered bronze or any other metallic surface which surface is
covered all over with indentations, corrugations or irregularities of any suitable
form or kind or with fine grooves or striations arranged perpendicularly or other-
wise if desired upon the said surface for the purpose when in use of causing the
rays of light to be scattered laterally and thus increasing the lateral reflection of
the light and thereby causing the projected image or images to be seen with equal
brightness from any point of view within reasonable limits. To remedy the defect
of buckling when the screens are faced with paper metallic foil or other substance
before referred to we paste or otherwise apply a coating or lining of paper or other
suitable material to the back of the screen of sufficient strength or substance to
counteract the strain of the front surface and thus obtain a flat and even hang of
the screen.
By these means much better results are obtained in all cases than by the present
arrangements.
We do not necessarily limit ourselves to the more precise details herein set forth
as we may sometimes deem it expedient to vary the same without departing from
the essential features comprising the principle of our improvements but,
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is-
Firstly. An improved screen for optical projection purposes produced in the
manner and for the purpose substantially as herein set forth and described.
Secondly. In screens composed of any suitable material or substance for use
with magic lanterns, lantern-microscopes and all other optical projection and
reflecting apparatus we claim the combination with the calico, linen, or canvas,
covering of said screen, or upon walls or other situations, of a surface composed of
silver or other metal or metallic sheets, of filins, leaves, or powdered bronze or any
other suitable surface of metal, and the formation and arrangement in or upon the

page_text: said metallic surface of a series of fine grooves or striations arranged perpen-
dicularly or otherwise, or indentations, corrugations, or other irregularities of any
kind upon said metallic surface for the purpose herein set forth and described.
Thirdly. In screens the means for remedying the defects caused by possible
liability of the surfaces buckling when faced with paper metallic foil or other
substance likely to buckle when strained.
Dated this 22nd day of September 1896.
EDWD. J. PAYNE & SON,
Warwick Chambers, 104, Colmore Row, Birmingham,
Patent Agents for the Applicants.
EDWD. J. PAYNE & SON,
Warwick Chambers, 104, Colmore Row, Birmingham,
Patent Agents for the Applicants.