US1535142A - Photographic-printing mask - Google Patents

Description

April 28, 1925.

P. R. WATSON ET AL PHOTOGRAPHIC PRINTING MASK Filed lay 19, 1921 MLK/LIW QM 0, MM

Patented Apr. 28, 1925.

UNITED STATES 1,535,142 PATENT OFFICE.

. PERCY RONALD WATSON AND WILLIAM OSBORNE TILSLEY, OF TE AROHA, NEW

ZEALAND.

PHOTOGRAPHIC-PRINTING MASK.

Application filed May 19, 1921.

To all whom it may concern:

Be it known that we, PERCY RONALD VAT- SON and \VILLIAM OSBORNE TILSLEY, subjects of the King of Great Britain, residing at Vhitaker Street, Te Aroha, in the Dominion of New Zealand, have invented a new and useful Photographic-Printing Mask, of which the following is a specification.

This invention has been devised with the object of providing improvements in the masks used in the printing of photographs, and generally formed by loose sheets of nonactinic material, such as black paper, having openings therein, that are adapted to be laid over the negatives so as to cover it up all round its edges and thereby provide for a clear margin all round the photograph ob tained by exposure of the photogaphic paper laid upon such negative and properly positioned with regard to the mask.

These loose masks are subject to particular disadvantages in their use, more especially the liability to move and alter the register of the negative, mask and paper, when being clamped in the printing frame, and also the necessity of having to re-arrange the mask and negative after each exposure to receive the paper for the next exposure.

The present invention overcome-s these disadvantages and provides that when once the negative and mask have been positioned they will maintain their relative positions, and it also provides that with a single mask frame adapted to a maximum size of expo sure opening, any number of masks having variable openings of smaller sizes than the maximum, may be used so as to accommodate the said frame for use with equal effectiveness, with smaller negatives.

The invention is more particularly adapted for use in printing from film negatives, although it may be used with some efi'ectiveness in conjunction with glass negatives.

The invention consists in the provision of a glass sheet, that will form the front of a printing frame, with masked edges all round, so arranged as to leave the maximum exposure surface of the printing frame clear and so secured to the glass face that a pocket. is formed between its edges and the glass. into which the negative may he slipped, and into which also other mask sheets may be slipped, as required, to provide for masks of smaller sizes upon negatives also of smaller sizes than that of the maximum.

Serial No. 470,992.

The engagement of the edges of the mam mask with the edges of the negatives and of the other mask sheets will then hold such negatives and masks securely in position in their properly adjusted relative positions. This glass with the negative and mask in position therein is placed in the printing frame and the photographic paper positioned over them in the usual way and clamped into the frame for exposure printing in the ordinary manner.

This special construction of masking means is shewn in the accompanying drawings, in which Figure 1 is a plan of the mask frame with a smaller mask sheet in position therein.

Figure 2 is a transverse section of the mask frame.

Figure 3 sheets.

A is the glass sheet which is made of any approved size, but preferably of a size corresponding to that of the maximum size of print required. This sheet has its four edges bound with masking material B, such as a stiff black paper, which is carried over the several edges to extend loosely on the back surface of the glass for distances such as to provide the masking and to leave the clear central space for the exposure opening. This binding is, however, split along one end of the sheet, as at C, so as to form a mouth or slit through which negatives or sheets of mask paper of the proper sizes may be slipped so as to extend over the sheet and to be held in place by the grip of the mask edge B upon their edges. Such a masking sheet is shewn in Fig. 3 and in position, as D, in Fig. 1. The central openings in such sheets being varied in sizes and shapes, it will follow that the mask frame may be used to hold a mask for any desired size of negative and such negative may then be held in place by insertion between its mask and the surface of the glass A. The tension of the surface engagement of these, will then retain the mask and negative in their proper relative positions, so that the printing sheets may be placed over the negative and mask in the usual way when such have been placed in the printing frame and the printing proceeded with by exposure in the ordinary manner.

e claim v l. A masking device for holding masking is a plan of one of the mask a through which masking sheets may be sheets in photographic printing comprising a sheet of glass, and non-actinic material supported by the glass and extending loosely inward over one surface of the glass to form a pocket on such surface and having an entrance opening along one edge of the glass slid into said pocket.

2. A masking device for holding masking sheets in photographic printing comprising a sheet of glass, and an edging of non-actinic material permanently carried by the glass and forming a pocket withone surface of the glass, said edging on the glass having an opening along one edge of the glass through which a masking sheet may be slid into said pocket, said opening also permitting a photographic film to be inserted between the masking sheet and the sheet of glass.

In testimony whereof, we afiix our signatures.

PERCY R. WATSON. WILLIAM OSBORNE TILSLEY.

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