US1744862A

US1744862A - Picture-printing quality-detector device

Info

Publication number: US1744862A
Application number: US647824A
Authority: US
Inventors: Clarance B Blethen
Original assignee: Individual
Current assignee: Individual
Priority date: 1923-06-26
Filing date: 1923-06-26
Publication date: 1930-01-28
Anticipated expiration: 1947-01-28

Description

Patented Jan. 28, 1930 UNITED STATES CLARANCE B. IBLETHEN, OF SEATTLE, WASHINGTON :PICTURE-PRINTING QUALITY-DETECTOR DEVICE Application filed June 26,

My invention relates to the art of a picture printing quality detector device. More particularly, my invention relates to a device whereby the printing quality of .a picture being considered for reproduction in a newspaper by the half-tone process may be delinitely determined.

According to modern practice methods obtaining in newspaper establishments, the selection of photographs, which may be reproduced by the half-tone process with suitable printing effects, is a difficult task requiring great skill and 'long experience and ability possessed in rare instances. Many excellent photographs are not suitable for reproduction by the half-tone process for newspaper purposes. Finely finished photograhs, those which are really artistic, seldom make satisfactory newspaper illustrations when reproduced by the half-tone engraving process. Such pictures may be, and are, satisfactorily reproduced by the use of exceedingly fine half-tone screens which cannot be employed in newspaper work or by offset processes,

which are only suitable for slow printing of extra fine supplements on high qualities of glazed paper. In reproducing pictures by the half-tone process, it is well known that the graduation of tone in the photograph is reproduced by a graduated system of dotted and checkered spots, usually nearly invisible to the unaided eye, produced by the interposition between the camera and the object of the screen. The interposition 5 of lthis screen tends to operate to reduce the light derivable from the picture, i. e., the printed picture will normally be of a darker tone than that of the picture repro- 4 0 duced.. I

In order to knowwhat pictures may be reproduced by the half-tone engraving process with satisfactory results, a fundamental requisite is the ability to visualize the difference between the photograph on hand and the illustration which will later appear in the newspaper when that illustration is made by the half-tone process. Thorough training in dry and wet plate photography and zinc engraving, reinforced with long experience,

1923. Serial N0. 647,824.

is requisite in developing the poweror ability to visualize this difference.

Furthermore, a requisite which must be met by a device to accomplish the purpose indicated herein is that the device should not depend upon color primarily as the means to produce the dimmed eect which the picture will have when reproduced on the printed page, because, if the device were to depend primarily upon color, it would be useless for those who may be affected to a greater or less extent with color-blindness. A primary purpose of my invention is to provide a device that is free of such objection.

Another primary object of my invention is to provide a device which will reproduce in the eye of the examiner of a photograph,

being considered for reproduction for printing in a newspaper' by the half-tone engraving process, the printing quality or tone of that photograph. A further primary object of my invention is to provide a mechanical means, which will produce in the eye of the examiner the picture, as it will appear when printed, by way of an illusion, which illusion correctly indicates the printing quality or tone of the photograph, i. e., the general effect due to the combination of light and shade, so that by the aid of a device enibodying my invention the tone induced or created by the half-tone screen will be reproduced directly by the photograph being examined. In short, it is my purpose to provide a device by means of which any person, that is, one who has not had the advantages of the training and experience above indicated, can see by means of the assistance of the same what to all intents and purposes will be exactly the printed result.

The above mentioned general objects of my invention, together with others inherent in the same, are attained by the device hereinafter described and illustrated in the following drawings, the same being merely a preferred exemplary form of embodiment of my invention, throughout which drawings like reference numerals indicate like parts:

Figure l is a view in perspective of a picture printing quality detector embodying my invention;

.and the photograph being reproduced.

hue differing from that of the picture beingY Vexamined and'having a mesh of hexagonal form, may be operatively disposed in the

wooden hoops

6 and 7 after the. mannerfof embroidery hoops, undersuch tension as to cause the said screen to'lie fiat in one plane between apsupporting glass 8 and a cover glass 9. Under the peripheral portion ofV glass 8 may be disposed a ring l0, which ring preferably'has' an inwardly directed flange 1l and a base l2, which has an upturned flange 13. A ring' 14', with inwardly directed flange 15', may be provided to enclose

hoops

6 and 7 and embrace the peripheral portion of the cover glass 9. p

Small bolts 16l serve to clamp the

rings

10 and 14 together and these rings securely embrace

hoops

6 and 7 therebetween. A handle 17 is provided as a means for gripping the device.

The mode of operation of a device embodying my invention is as follows: The mechani-l cal operation, so far as the construction oi' the deviceis concerned, will be readily understood, without further elaboration, from the description already set forth. It is manifest that the means' employed all function to one end, namely, to provide a device for maintaining' a screen 5 in a flat position, i. e., disposed in one plane, and to provide means whereby this screen may be conveniently positioned over pictures, which picturesI are to be examined for the purpose of determining their printing quality.

Analysis of the operation of the device embodying my invention from the point of view of optics reveals the following as its principle of operationfl The principle of the halftone process of reproducing pictures depends upon reproducing the gradation of tone of the photograph by a graduated system of dotted and checkered spots, produced by the interposition of' a screen between the camera It results that this screenoperates to reduce the light derivable from the picture, so that the new picture, (therefore, the printed picture),

produced from the photograph will be nor- A mally of a vdarker tone than that of the photograph being reproduced. Therefore, to produce a mechanical means which will create in the mind, of the examiner the same impression as will appear in the form of the printedv picture, it isv necessary that suitable means be employed to shut off the light in a manner which will be identical, or practically identical, in effect to that of the half-tone screen.

Obviously, dark colored glass is not suitable for such purposes, inasmuch as many operators may be more or less affected with colorblindness. l, therefore, provide a screen, the mesh of which is of suitable form and material to reproduce the illusion of the printing quality of a given photograph. A metallic screen does not' give as desirable results as a mereerized cotton. Actual experience has taught me that satisfactory results may be obtained when a net or screen is employed, having a mesh with openings of hexagonal form, and experience has further taught that best results may be obtained when these openinos number about sixteen to the lineal inch, where the half-tone screen, which will beemployed in the reproduction of the picture, has about sixty openings to the inch. Furthermore, experience has developed that the hue of the screen shouldv be dark blue, approximately half way between what is known as sky7 and navy blue. However, be it noted that various colors and various forms and sizes of mesh will work in this device. The hue of the screen should depart from that of the picture being inspected, and the above is set forth to indicate what has been folund by my experience to give the best resu ts.v

Having indicated the character of the screen which may be employed, the next ele.

ment in the operation of my device is concerned with the distance whichl this screen must be disposed above the picture being examined to produce the proper effect. Each of the openings of the screen constitutes a small opening through which the photo-y graph-beneath is viewed. To dispose. the screen directly upon the picture is not productive of any illusion, but by disposing the said screen approximately one-half inch above the photograph being examinechmy experiencey teaches that the proper focusas 4it were is provided, and a very satisfactory reproduction of the printing qualit-y of the particular' picture is provided.

The device illustrated as embodying my invention has'the depth of the ring l0 and the thickness of the glass 8 of such proportions as to dispose the screen 5 approximately one-half inch above the photograph when theV base 12 is caused to rest upon the photograph:

The device thus described and explained` renders it possible for the observer to have created for him a picture, when viewed through the said screen so disposed above the photograph, Vwhich to all intents and purposes is a duplicate of whatV will appear on Athe printed page, when the photograph is reproduced thereon; The device embodyingV my invention thus creates a picture, the tone of which is that of the photograph when it is printed.V ln short, the final effect created is that the observer does not consciously look ico through the screen 5 of my invention to the photograph below, but what he sees is an illusion of the photograph with its tones reproduced with the character which they will have when printed.

Ob iously, changes may be made in the form, dimensions and arrangement of the parts of my invention without departing` from the principle thereof, the above setting forth only a preferred form of embodiment.

l claim:

l. A picture half-tone process printing quality detector embodying` a frame; having a picture engaging edge; and a screen operatively held in said frame spaced about onehalf inch above the plane of the picture engaging edge of said frame, the mesh of the screen being so related in size to the halftone screen and being spacedat such a distance above the picture engaging edge of the frame that the tone of the printed picture created by the half-tone glass screen in the half-tone process may be approximately reproduced, whereby the tone ofthe printed picture created by the half-tone glass screen in the half-tone process may be approximately reproduced in the eye of the examiner directly by the picture itself.

2. A picture printing quality detector for use in connection with the half-tone process embodying a frame having a picture engaging edge; and a screen operatively held in said frame in spaced relation above the plane of the picture engaging edge of said frame, said screen having a mesh of approximately sixteen to the lineal inch where the half-tone screen has about sixty openings to the inch, whereby the tone ofthe printed picture created by the half-tone glass screen in the half-tone process may be approximately reproduced in the eye of the examiner directly by the picture itself.

3. A picture half-tone process printing quality detector embodying a frame having a picture engaging edge; and a screen operatively held in said frame in spaced relation above the plane of the picture engaging edge of said frame, said screen having a mesh of hexagonal form, the mesh of the screen being so related in size to the half-tone screen and being spaced at such a distance above the picture engaging edge of the frame that the tone of the printed picture created by the half-tone glass screen in the half-tone process may be approximately reproduced, whereby the tone of the printed picture created by the half-tone glass screen in the half-tone process may be approximately reproduced in the eye of the examiner directly by the picture itself.

4. A picture printing quality detector for use in connection with the half-tone process embodying a frame having a picture engaging edge; and a screen operatively held in said frame spaced about one-half inch above the plane of the picture engaging edge of said frame, said screen having a mesh of hexagonal form and approximately sixteen to the lineal inch where the half-tone screen has about sixty openings to the inch, whereby the tone of the printed picture created by the half-tone glass screen in the half-tone process may be approximately reproduced in the eye of the examiner directly by the picture itself.

5. A picture half-tone process printing quality detector embodying a frame having a picture engaging edge; and a screen of textile fabric operatively held in said frame in spaced relation above the plane of the picture engaging edge of said frame, said screen being of a hue which differs from that of the picture being inspected, the mesh of the screen being so related in size to the half-tone screen and being spaced at such a distance above the picture engaging edge of the frame that the tone of the printed picture created by the half-tone glass screen in the half-tone process may be approximately reproduced, whereby the tone of the printed picture created by the half-tone glass screen in the halftone process may be approximately reproduced in the eye of the examiner directly by the picture itself.

6. A picture printing quality detector embodying a frame having a picture engaging edge; and a screen of textile fabric operatively held in said frame in spaced relation above the plane of the picture engaging edge of said frame, said screen having a mesh of approximately sixteen to the lineal inch where the half-tone screen has about sixty openings to the inch, whereby the tone of the printed picture created by the half-tone glass screen in the half-tone process may be approximately reproduced in the eye of the examiner directly by the picture itself.

7. A picture printing quality detector for use in connection with the half-tone process embodying a frame having a picture engaging edge; and a screen of textile fabric operatively heid in said frame spaced about onehalf inch above the plane of the picture engaging edge of said frame, said screen having a mesh of hexagonal form and approximately sixteen to the lineal inch where the half-tone screen has about sixty openings to the inch, whereby the tone of the printed picture created by the half-tone glass screen in the halftone process may be approximately reproduced in the eye of the examiner directly by the picture itself.

8. A picture printing quality detector, to be used in the selection of photographs to be reproduced by the half-tone glass screen in the half-tone process, embodying` a frame having a picture engaging edge; two colorless sheets of giass operatively held in said frame in spaced relation above the plane of the picture engaging edge of said frame; and

a screen, the number of openings per square inch in which screen bears a relation to the number of openings per square inch in said half-tone glass screen, said screen being of textile fabric disposed in expanded position between said supporting sheets of glass2 whereby the tone of the printed picture created by the half-tone glass screen in the halftone process may be approximately reproduced in the eye of the examiner directly by the picture itself. f

9. A picture printing quality detector for use in connection With the half-tone process embodying a frame having a picture engaging edge; two sheets of colorless supporting glass, operatively held in said frame spaced about one-half inch above the plane of the picture engaging edge of said frame; and a screen of textile fabric disposed in expanded position between said sheets of glass, said screen having a mesh of hexagonal form and approximately sixteen to the lineal inch where the half-tone screen has about sixty openings to the inch, whereby the tone of the printed picture created by the half-tone glass screen in the halftone process may be approximately reproduced in the eye of the examiner directly by the picture itself.

In witness whereof, I hereunto subscribe my name this 26th day of June, A. D. 1923.

CLARANCE B. BLETHEN.