US2985088A

US2985088A - Half-tone visual film scanner

Info

Publication number: US2985088A
Application number: US778742A
Authority: US
Inventors: Taylor Philip
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-12-08
Filing date: 1958-12-08
Publication date: 1961-05-23
Anticipated expiration: 1978-05-23
Also published as: US3021750A

Description

May 23, 1961 P. TAYLOR 2,985,088

HALF-TONE VISUAL FILM SCANNER Filed Dec. 8, 1958 2 Sheets-Sheet 1 8 INVENTOR. PHILIP TAYLOR ATTORNEY f May 23, 1961 P. TAYLOR 2,985,088

HALF-TONE VISUAL FILM SCANNER Filed Dec. 8, 1958 2 Sheets-Sheet 2 INVENTOR. PHILIP TAYLOR #2 MW ATTORNEY 2,985,088 HALF-TONE VISUAL FILM SCANNER Philip Taylor, 1903 E. Moyamensing Ave., Philadelphia, Pa.

This invention relates to a device for use particularly in photo-lithography, photo-engraving and like processes.

It is well known in photo-lithographing that the relative dot size is the determining factor in the development of half-tone film negatives or positives. Consequently, the practice today is to remove the film material from the developer and view the same via transmitted light under magnification while the film material is held in a vertical position. Because the oxidative rate of the developer (generally paraformaldehyde) is very high, the heat of the hand in holding the film and the unevenness of flow of the developer down the film causes mottling and streaking in the film, frequently rendering the film unusable thereafter.

The primary object of the invention is to provide a device which overcomes the disadvantages noted above. By enabling the film to remain in the developer and to be viewed by reflected light in a horizontal position, the device affords an economical and easily operated means for scanning the film under magnification Without fear that mottling and streaking will occur during inspection. The device will therefore also enable the operator to make a thorough rather than rapid and perfunctory examination of the film while easing the tension of the operator during such inspection.

Another object of the invention is to provide a visual half-tone scanner which is provided with a safelight magnifier and means to move the same in all directions over the developing bath.

Another object of the invention is to provide a scanner of the character described wherein a means is provided for raising the film in the developer to the surface thereof to allow for better focusing without having the magnifier contact the developing solution.

Another object of the invention is to provide a scanner of the character described wherein the same may be inserted in existing developing trays or constructed as a tray unit itself.

These and other objects will become more apparent as the following description proceeds in conjunction with the accompanying drawings, wherein:

Figure 1 is a perspective view of one form of the device;

Figure 2 is a fragmentary perspective view of the device looking down on the bottom of the device with elevating platform removed;

Figure 3 is an enlarged vertical sectional view through the magnifier; and

Figure 4 is a perspective view of another form of the invention.

Specific reference is now made to the drawings wherein States Patent 2,985,088 Patented May 23, 1961 similar reference characters are used for elements throughout.

Referring first to Figures 1-3, the device comprises a tray having a bottom wall 10,

end walls

12 and 14 and

side walls

16 and 18, it being understood that the tray may be of any desired size and depth and may be fabricated of any suitable material resistant to attack by developing solutions. The upper edges of the end walls 12 and '14 are provided with outwardly extending horizontal flanges 20 whereas the upper edges of the side walls 16 and 13 are provided with outwardly extending horizontal flanges 22. The flanges 20 are extended beyond the side wall 18 a predtermined distance as at 24, the extensions terminating in vertical stops 26 for a purpose later to appear.

Extending across the tray and slidably engaging the end flanges 20 is a pair of

rods

28 and 30 which are retained at their ends in substantially

flat members

32 and 34 slidably disposed against the outside edges of said flanges 20.

A magnifier unit 36 is provided and as shown in Figure 3, comprises a cylindrical casing 38 having a shoulder portion 40 with a viewing opening 42 axially therethrough. The casing 38 extends slidably through an opening in a substantially rectangular retainer 44, there being a set screw 46 through one edge of the retainer to retain the casing in an axially adjusted position in the retainer 44. A pair of opposed ends of the retainer 44 are provided with elongated cut-outs or grooves 48 in which the

rods

28 and 30 are received so that the magnifier is slidably mounted on the rods for movement along their length.

The magnifier unit also includes an inwardly extending corresponding .flange 50 which removably retains an axially extending housing 52 which mounts suitable magnifying lenses 54. The entire housing with the mounted lenses may be replaced to change magnification, if desired. In the annular space between the lens housing 52 and the casing 38 is suitably mounted illuminating units, such as light bulbs 56 which are operatively connected to conductive Wires in an extensible cable 58, one end of which is provided with a suitable male socket (not shown) for insertion into a conventional female socket (not shown) of a suitable electrical source. The circuit desirably includes a variable transformer (not shown) to control the voltage input to the bulbs 56 to vary their illumination intensity when required. At one point the cable is retained in a suitable insulated grommet 69 carried by a vertical extension of member 34 so that the cable will not interfere with the operator during the viewing procedure when the magnifier unit is moved about.

The lower end of the casing is provided with a diffusing glass 62 such as, for example, flash opal, beneath which is retained a safe glass or red filter 64 which is photographically safe for orthochromatic sensitive material.

Adjacent the corners of the tray, the bottom wall 10 is provided with opposed

upstanding bearings

66 and 68. Journaled in each pair of opposed bearings is a crank member 70, the ends of the crank member extending through the bearings 68 and including an angulated extension 72 terminating in an eye 74.

An operating handle 76 is provided in the form of a lever bar 78 which carries intermediate its ends a pintle 80 which is pivoted in a suitable aperture in the side wall 16. The upper end of the lever bar 78 is provided with a L-shaped portion 82 which extends around the flange 22 on the side wall 16. A first tie rod or link 84 hooks into the eye 74 of one crank member 70 and into an aperture in the lever bar 78 as at 86 and a second tie rod or link 88 hooks into the eye 74 of the other crank member and into an aperture provided in the lower end of the bar as at fill. The arrangement of the crank members and links and their operative connection to the lever bar is such that the crank members lie substantially flat against the bottom wall of the tray, as shown in Figure 2, when the lever bar is over to the left of the figures. A substantially flat platform 92, perforated if desired, approximating but somewhat less than the dimensions of the bottom wall is positioned over the crank members.

The device of Figures 13 is intended for use as a combined developing tray and scanner. The device of Figure 4 is intended for use as a scanner per se for insertion in existing developing trays. It is therefore basically the same as the first device except that it does not contain continuous side and end walls. Instead, it comprises a bottom wall 10', the corners of which carry upstanding posts 12' joined by end members or rails 14'. The bottom wall is provided adjacent the posts with pairs of opposing bearings 66' and 68 in which are journaled the ends of crank members 70. Extensions 72 terminating in eyes 74 are provided at the ends of the crank members which pass through the bearings 68. An operating handle 76' including a lever bar '78 is pivoted intermediate its ends as at 86' to a portion 82' upstanding from the bottom wall 10'. A first link 84 is terminally hooked into the eye 74' of one of the crank members 76' and into an aperture provided in the lever bar 78 and a second link 86' is terminally hooked into the eye 74 of the other crank member and into an aperture provided in the lower end of the lever bar 78. The construction and operation of the lever bar, crank members and links of this form of the invention is the same as that previously described. There will also be a platform 92 for placement upon the crank members 7i? and the magnifier unit 36 and rod mountings 23 and 36 therefor will be positioned on the rails 14.

In use, with the position of the handle 76 as shown in Figures 1 and 2, the film is placed in the tray so that it rests on the platform 92 while it is acted upon by developing solution in the tray. When the time comes for visual inspection of the dot formation in the film, a switch (not shown) is actuated energizing the illuminating elements 56 in the magnifier unit 36. By moving the magnifier unit lengthwise of the rods 28 and between the

end Walls

12 and 14 and vice versa and by moving the magnifier unit with its mounting rods 28 and 39 as a unit between the

side walls

16 and 18, it will be seen that every portion of the film can be readily viewed through the magnifier unit, the light from the magnifier unit being well reflected from the black exposed converted metallic silver and the white unexposed silver salts on the film. To adiust focusing, the set screw 46 can be used to adjust the vertical position of the casing 38 in the retainer 44. Also the piate 92. supporting the film can be adjustably raised by moving the handle 7s to the right as shown by the arrow A in Figure 2 whereby the portions of the crank members 79 between the bearings rotate in the direction of the arrows B lifting the platform 92 and the film closer to the magnifier unit and preferably to the liquid level of the developing solution. Since the extension 82 of the handle 76 frictionally engages the flange 22, the platform 92 may be retained at various levels. serrations on the edge of flange 2-2 may also be used for this purpose. The raising of the film on the platform will also assist the operator in removing the developed film from the solution. At this stage, the magnifier unit and its mounting rods 23 and 3% can be moved onto the flange extensions 24 to be stopped by the members 26 at which point the rod 28 clears the side wall 18 of the tray and 4 the film can be readily removed therefrom. It will be manifest that the operation of the tray insertion unit of Figure 4 operates in substantially the same manner.

While preferred embodiments of the invention have been shown and described herein, minor variations may be made by skilled artisans without departing from the spirit of the invention and the scope of the appended claims.

I claim:

1. In combination with a substantially rectangular tray having a bottom wall, side and end walls and adapted to retain a developing solution and film therein, a film scanner comprising a member slidably mounted on the end walls for movement between said side walls and spanning said tray, a viewing device including a magnifier unit, an illumination element and a safelight filter, and means slidably mounting said viewing device upon said member for movement of said device lengthwise of said member between said end walls.

2. The combination of claim 1 and a film-supporting platform in said tray and means to raise and lower said platform towards and away from said viewing device.

3. The combination of claim 2 wherein said means to raise and lower said platform includes elongated crank members pivoted at their ends to said bottom wall beneath said platform, an operating handle pivoted to one of said side walls and links terminally pivoted to said handle and to each crank member whereby movement of said handle in one direction disposes said crank members flat against said bottom wall and movement of said handle in an opposite direction raises said crank members above said bottom wall, thereby elevating said platform.

4. The combination of claim 1 wherein said member includes a pair of spaced rods and said means slidably mounting said viewing device upon said member includes a retainer carrying said magnifier unit, illumination element and filter and grooves in said retainer receiving said rods.

5. The combination of claim 4 and extensions on said end walls beyond one of said side walls with terminal stops on said extensions whereby said spaced rods and said viewing device mounted thereon may be moved onto said extensions to clear said one side wall.

6. A film scanner adapted for insertion in a developing tray comprising a substantially rectangular flat plate having side and end edges, upright posts carried by said flat plate adjacent its corners, rails joining the posts along said end edges, a member slidably mounted upon said rails for movement between said side edges and spanning said plate, a viewing device including a magnifier unit, an illumination element and a safelight filter and means slidably mounting said viewing device upon said member for movement lengthwise of said member between said end edges.

7. The combination of claim 6 wherein said member includes a pair of spaced rods and said means slidably mounting said viewing device upon said member includes a retainer carrying said magnifier unit, illumination element and filter and grooves in said retainer receiving said rods.

8. The combination of claim 6 and a film-supporting platform substantially coextensive with said flat member and means to raise and lower said platform towards and away from said viewing device.

9. The combination of claim 8 wherein said platform raising and lowering means includes elongated crank members terminally journaled on said flat member, an operating handle pivoted to said flat member adjacent one side edge thereof, and links terminally pivoted to said handle and each of said crank members whereby movement of said handle in one direction disposes said crank members against said flat member and movement of said handle in an opposite direction raises said crank members, thereby elevating said platform.

10. In combination with a substantially rectangular tray having a bottom wall, side and end walls and adapted to retain a developing solution and film therein, a film scanner comprising a pair of rods slidably mounted on said end walls for movement between said side walls, a casing, a magnifying viewer removably mounted in said casing, an illumination element mounted in said casing, a safelight filter carried by said casing beneath said illumination element, a retainer slidably mounted on said rods for movement between said end walls, said casing extending through an aperture provided in said retainer, and a set screw carried by said retainer holding said casing thereon in adjustably fixed positions.

References Cited in the file of this patent UNITED STATES PATENTS Peters Apr. 26-, 1904 Parker Nov. 28, 1916 Horn et a1 Dec. 5, 1916 Ahlberg Oct. 29, 1929 Cerny et a1 Aug. 6, 1940 Kibbe July 7, 1942 Borth Nov. 3, 1953 Korner et a1. Nov. 25, 1958 Schiller Dec. 2, 1958