US2303206A - Photographic contact printing apparatus - Google Patents

Description

Nov. 24, 1942. c P, GARMAN 2,303,206

PHOTOGRAPHIC CONTACT PRINTING APPARATUS Filed Feb. 24, 1940 '2 Sheets-Sheet l INVENTOR. 0mm 53 61mm? ATTORNEY.

NOV. 24, 1942. c, GARMAN 2,303,206

PHOTOGRAPHIC CONTACT PRINTING APPARATUS Filed Feb. 24, 1940 2 Sheets-Sheet 2 019mm 679mm I ATTORNEY.

INVENTOR.

Patented Nov. 24, 1942 UNITED STATES PATENT OFFICE PHOTOGRAPHIC CONTACT PRINTING APPARATUS 4 Claims.

This invention relates to photography, and more particularly to improvements in photographic contact printing apparatus for reproducing, in positive form, a series of images which have been initially produced on a negative film by the usual photographic processes.

Negative images on a strip film appear in the order in which the exposures were made. It is highly desirable to be able to print images from such negatives in varied sequences, and to omit those negatives which are not desired. It is also desirable to print the images a predetermined distance apart. In printing a series of images on a strip positive, it is desirable to have no double exposures and no spaces in which a print has not been made.

At present printers of the type to which the present invention relates depend upon the memory of the operator to move the positive film into position for printing. Blank spaces and double exposures commonly result. In manually advancing the positive printing material, it is diflicult to obtain the predetermined distance between prints on the positive printing material.

The principal object of the invention is to provide a contact printing device of the character described, by which the positive printing material is automatically advanced a predetermined distance prior to each exposure.

Another object of the invention is to provide a photographic printing device of the character described which may be readily operated to reproduce a series of images in the same order or sequence that they appear on the negative film strip, or, to reproduce the images in any other desired sequential order, or, to omit particular images, the reproduction of which is not desired,

without leaving blank spaces, or double exposures on the resultant positive strip.

Another object of the invention is to provide a printing device of the character described wherein unintentional exposure of several images to a single positive receiving surface, or double exposure is effectively prevented and to prevent the unintentional advancing of the positive printing material without having exposed the same to the desired negative.

Another object of this invention is to provide a printing device of the character described in which the distance between successive images on the positive strip are the same, and to provide means for predetermining this distance.

A further object of this invention is to provide a more critical control of the time of exposure of the printing material.

The foregoing and other objects and advantages are attained in a photographic contact printer comprising, briefly, a light box supporting a negative platen having an exposure aperture and means of holding a strip negative in place over said aperture. Said light box contains an electric lamp arranged in a circuit so as to be continuously energized at a voltage below that at which the lamp emits actinic light. Switch means are provided to place full voltage across the lamp for the time of the desired exposure. A film magazine is provided. This magazine is so made that unexposed film or other strip photographic material can be placed in one section thereof and threaded to a second section thereof. The upper casing or magazine is supported by a shaft which in turn is supported by the light box. The magazine can be rotated on said shaft to bring the positive film in contact with the negative film over the exposure aperture, and in turn rotated away from printing position so that the negative can be observed by the oper ator. Secured to this shaft is a spiral gear, and a ratchet wheel. Normal to this shaft is a spindle to which are secured a mating gear to the aforesaid spiral gear, a slotted disc, one member of a gear train and a film sprocket. A pawl engaging the ratchet wheel holds the shaft stationary while the positive film magazine is being rotated about the shaft out of printing position causing the mating spiral gear to rotate, thus giving rotary motion to the film sprocket which serves to advance the positive film within the positive film magazine. The slotted disc and engaging spring member serve to index the advance of the positive printing material within the magazine.

The invention is disclosed by the following detailed description of presently preferred embodiment of the invention wherein reference is made to the accompanying drawings in which like characters denote like and corresponding parts throughout the several views.

Fig. l is a partially cut away side elevation of a photographic contact printer embodying the invention, the magazine being in printing position;

Fig. 2 is a partially cut away end elevation, viewed on the line 2-2 of Fig. 1;

Fig. 3 is a plan view of the negative film platen removed from the light box;

Fig. 4 is a transverse section taken on the line 4-4 of Fig. 2;

Fig. 5 is a fragmental end elevation with the magazine out of printing position;

Fig. 6 is a fragmental end elevation with the magazine approaching the printing position;

Fig. '7 is a wiring diagram of the printer.

Referring more particularly to the drawings, I is a light box or base structure with hollow base Within the light box It) and supported by base i which forms the bottom of the light box |l are two electric lamp sockets I2 and I4. Lamp socket i2 contains lamp |3 which when energized emits white or actinic light. Socket l4 contains ruby lamp [5 which is a safe light for ordinary photographic emulsions. I6 is a removable metal platen supported by shoulder 9 of light box H1 and forms the cover of the light box Iii. H is an exposure aperture extending through platen |6. I8 is a transparent glass window set in aperture I1 so as to be flush with the metal surface H! of platen I6. 23 and are negative film guides attached to platen IS on either side of aperture ii. 22 is a negative film spool supported by bracket 23, which in turn is attached by means of clamp 24 and screw 25 to one end of the light box it. Attached to the opposite end of light box |0 by screw 25' is clamp 24 which supports brackets 23 which in turn supports negative film spools 22'. Film spool 22 and 22' are frictionally coupled to bracket 23 and 23' respectively. 3| is a negative film and is usually indexed by numerals (not shown) placed between the perforations 3| and the edge of the film which serve to identify individual exposures. Apertures 2|, 2| extending through platen I6 are placed so as to be under the film 3| and between the perforations 3| and the edge of the film permitting observation of the above mentioned numerals. It is preferable that these apertures 2|, 2| contain ruby or red transparencies.

Plug 18 connected to lamp cord 19 is adapted to be plugged into a conventional source of electrical energy. Wiring connected to cord 19 is provided in hollow base II to provide means of energizing lamps l3 and |5. The circuits to lamps i3 and I5 pass through toggle switch 28 which has on and off positions. Between lamp l3 and switch 28 is resistance 26". This resistance has a value such that the voltage applied to lamp i3 is insufficient to permit lamp |3 to emit actinic light. Shunting resistance 26" is a momentary contact switch 2'1 in series with variable rheostat 26'. shunting the momentary contact push button switch 21 is an automatic time switch 27" which is a conventional time switch which can be set and actuated to close a circuit for a definite period of time and then open the circuit. Lamp shade 29 containing lamp 29 is positioned to illuminate rheostat knob 26. Lamp 29' is controlled by push button switch 21'. In turn lamp shade 30 containing lamp 30' is positioned to illuminate a small area on the front of base N. This lamp 30 is controlled by push button switch 21. This illuminated area provides the operator with means of reading cards upon which he has previously written the correct exposures and rheostat settings for particular negatives.

32 and 32 are brackets extending from the rear wall of light box I0. Shaft 34 is journalled to brackets 32-32 at 33 and 33 respectively. 35 is a printing material magazine or supporting means. This magazine is divided into three compartments 4|, 42, 43 by walls 44, 44. 4| is the unexposed film compartment and 42 is the exposed film compartment. 43 is the center compartment. 36 is a spindle journalled on the rear wall of compartment 4|.

. spiral gear 5|.

movably secured to spindle 35. 31 is a spindle journalled in the rear wall of compartment 42. 39 is a film spool removably secured to spindle 37. 40 is perforated positive film. Roller 48 is journalled at 41 to bracket 48 secured to wall 44. Bracket 49 is secured to wall 44 in compartment 42. Shaft or spindle 55 is journalled to bracket 49 at 5|. As a film advancing and feeding means, I provide a sprocket wheel 52 secured to spindle 5i Shaft or spindle extends through and is journalled to the rear wall of compartment 42. 54 is a glass platen mounted in the bottom face of compartment 43 and held in place by spring clips 55, 55. These spring clips limit the pressure between platen 54 and negative platen I6. 54 is a glass top for center compartment 43. 56 is a slit-like opening in wall 44. 53 is a felt material masking slit 56. 51 is a slit-like opening in wall 44'. Film magazine 35 is supported by bracket arms 58, 58 secured to the rear wall of film magazine 35. Bracket arms 58, 58' are journalled to shaft 34 at 59, 59. Secured to shaft 34 is a spiral gear 60 which meshes with mating Spiral gear 6| is secured to spindle 50 outside of compartment 4| of magazine 35. Also secured to spindle 50 between spiral gear 5| and the rear wall of compartment 42 is gear 62. Gear 62 meshes with idler gear 63 which in turn meshes with idler gear 64 which in turn meshes with gear 55. Idler gears 63 and 64 are secured to spindles G3, 66' respectively, which are journalled to the rear wall of compartment 42. Gear 85 is secured to frictional clutch 68 (details not shown). Frictional clutch 68 is secured to spin- 38 is a film spool re- H! is an extension to pawl 10.

dle 31 outside of the rear wall of compartment 42. 5'! is an adjusting screw for frictional clutch 53.

Secured to one end of shaft 34 is a ratchet wheel 69. Pawl 10 is secured to bracket 32 by screw ll. 12 is a spring in compression between extension 10' and bracket 32. Between spiral gear SI and gear 62 is slotted disc 13 secured to spindle 50. 14 is an indexing spring member or detent engaging slotted disc or ratchet l3, and is secured to bracket 58 by means of screw i5. 16 is a cover for compartment 42 held in place by thumb screw 1 1.

In operation cover 16 is removed from compartment 42 by loosening thumb screw 11. In a similar manner the cover of compartment 4| is removed. Film spool 36 containing unexposed perforated positive film 40 is placed on spindle 36. Film 4|) is threaded over roller 46, through slitlike opening 56, under platen 54, through slit-like opening 57 over sprocket wheel 52, and connected to receiving film spool 39 on spindle 31. The covers are then replaced on their respective compartments 42 and 4| respectively. The negative film 3| whose images are to be printed is placed on negative film spool 22 and threaded through guides 29, 211' to film spool 22'. Plug I8 is plugged into a suitable source of electric current. Toggle switch 28 is operated into the on position energizing ruby lamp l5 and also energizing lamp i3 through resistance 26". The operator moves the negative film 3| by rotating film spools 22 and 22' manually to bring the desired image into position over aperture II. He is enabled to see the image of negative 3| by the ruby light |5 shining through glass Hi. If the negative film 3| is indexed by numerals, he is able to read these numerals by means of light shining through apertures 2| and 2|.

Magazine 35 is rotated about shaft 34 into a vertical position so that positive film 40 under platen 54 is directly over and in contact with negative film 3| on glass window l8. Push button 21 is depressed thus shunting resistance 26 causing lamp |3 to emit actinic light which passes through glass l8, the image of negative film 3|, to positive film 40, exposing that portion of positive film 40 directly over the single image of negative 3| which is over glass l8. Aperture l1 and glass H! are of such a size that a single image on negative 3| covers the glass and aperture completely. After the proper time of exposure has elapsed push button 21 is released by removing the pressure from it, opening the shunting circuit, thus cutting the supply of actinic light. If the time switch 21" is used the operator causes this switch to actuate, shunting resistance 26 in a similar manner. During the exposure the light passing through the films 3| and 40 passes through the glasses 54 and 54' permitting the operator to observe if the lamp l3 functioned to expose the film 40.

The magazine 35 is then rotated on shaft 3'4 away from the vertical, Pawl engages ratchet wheel 69 preventing shaft 34 from rotating. Spiral gear 30 being held stationary causes spiral gear 6| to rotate, rotating spindle 50 to which it is secured. This causes sprocket wheel 52 to rotate, which in turn advances the film over platen 54. Gear 62 rotates with spindle causing gear 65 to rotate through idler gears 63 and 64. Gear 65 rotates spindle 31 through frictional clutch 68. Rotation of spindle 31 rotates film spool 39 thus taking up the film fed into compartment 42 by film sprocket 52. Magazine 35 is rotated about shaft 34 until stopped by base As spindle 50 rotates, slotted disc I3 also rotates. Slotted disc 13 has 4 slots placed ninety degrees apart. Spring member 14 in contact with the periphery of slotted disc 13, due to friction, tends to prevent rotation of slotted disc 13. When the magazine travels through 90 degrees, spring member 14 drops into a slot of slotted disc 13 which increases the resistance to rotation of disc 13. Spring member 14 engaged in a slot of slotted disc l3- is not a positive resistance to rotation. Since pawl 10 engages ratchet wheel 69 positively and prevents rotation of shaft 34, continuing the rotation of magazine 35 beyond 90 causes spring member 14 to leave the slot and travel on the periphery of disc 13. When film magazine 35 reaches the limit of its travel of 180 degrees the spiral gears being of a ratio of 1 to l slotted disc 13 has also travelled through 180 degrees and spring member 14 engages a second slot in disc 13. Sprocket Wheel 52 is of such a diameter as to move the predetermined length of film over platen 54. The operator then moves the negative film 3| so as to place a desired negative image over aperture I1.

Rotating the film magazine 35 back to the printing position, pawl 10 rides on the face of the ratchet wheel 69 and does not engage the ratchet wheel 69. Shaft 34 is thus free to rotate. However spring member 14 in a slot of slotted disc 1'3 tends to prevent rotation of spindle 50. Thus spindle 59 and spiral gear 6| remain stationary causing spiral gear BI] and shaft 34 to rotate. Spindle 50 being stationary, sprocket wheel 52 and positive film 40 also remain stationary. If the magazine 35 in traveling out of printing position travels more than 180, spring member '14 will travel beyond the slot in slotted disc 13. In moving magazine 35 back to the printing position the frictional engagement of pawl it] against the face of ratchet wheel 69 is maintained by spring 12, which exceeds the friction'al engagement of spring member 14 against the face of slotted disc 13', but is less than the resistance to movement when the spring member 14 engages a slot in slotted disc 13. Therefore spindle'53 will rotate in a direction opposite to the rotation of spindle 50 when magazine 35 was beingrotated out of printing position until spring member 14 engages a slot in slotted disc 13, at which time spindle 50 will cease to rotate and shaft 34 will continue to rotate. This opposite rotation by spindle 50 causes film 40 to be fed ba .rward by sprocket 52 through slit-like openinglil. As positive film 40 comes in contact with negative film 3| the positive film 40 tends to be pushed into compartments 4| and 42. Due to the short column f film 40 between sprocket 52 and slit-like opening 51 film cannot be pushed into compartment 42. No such column effect is present in compartment 4|. Thus the slight ex- 'oe'ss length of film is pushed back into compartment 4|. Having exposed the negatives in the desired sequential order, the operator removes cover I6 of compartment 42 thus permitting the removal of film spool 39 making available the exposed positive film 40 for development.

Having described the invention with reference to a single, preferred embodiment thereof, it should be understood that various changes may be made in the construction and mechanism set forth in the present specification, without departing from the spirit and full intendment of the invention so defined by the appended claims.

I claim as my invention:

1. A photographic printing device comprising a light source having an exposure aperture, a pivotally mounted film magazine reciprocable between printing and non-printing positions with respect to said aperture, a rotatable gear mounted independently of said magazine, a ratchet having a rigid connection with said gear, a spring pressed pawl in engagement with said ratchet to yieldingly resist rotation of the ratchet and gear in one direction and to prevent rotation thereof in the opposite direction, a mating gear carried by said magazine meshing with said independently mounted gear, gearing operatively connected with the mating gear and the film for feeding the latter, a notched disc having a rigid connection with said mating gear, and a spring pressed detent for engagement with the notches of said disc and with the periphery thereof between the notches to yieldingly resist rotation of said disc and mating gear, the resistance effected by said detent exceeding the resistance effected by said pawl when the detent is engaged with a notch of the disc and being less than that of the pawl when engaged with the periphery of the disc between the notches.

2. A photographic printing device comprising a light source having an exposure aperture, a pivotally mounted film magazine reciprocable between printing and non-printing positions with respect to said aperture, a rotatable gear mounted independently of said magazine, means associated with said gear to yieldingly resist rotation thereof in one direction and to prevent rotation thereof in the opposite direction, a mating gear carried by said magazine meshing with said independently mounted gear, gearing operatively connected with the mating gear and the film for feeding the latter, a notched disc having a rigid connection with said mating gear, and a spring pressed detent for engagement with the notches of said disc and with the periphery thereof between the notches to yieldingly resist rotation of said disc and mating gear, the resistance effected by said detent exceeding the resistance effected by the means associated with the independently mounted gear when the detent is engaged with a notch of the disc and being less than that of said means when engaged with the periphery of the disc between the notches.

3. A photographic printing device comprising a light source having an exposure aperture, a pivotally mounted film magazine reciprocable between printing and non-printing positions with respect to said aperture, a rotatable gear mounted independently of said magazine, a ratchet having a rigid connection with said gear, a spring pressed pawl in engagement with said ratchet to yieldingly resist rotation of the ratchet and gear in one direction and to prevent rotation thereof in the opposite direction, a mating gear carried by said magazine meshing with said independently mounted gear, gearing operatively connected with said mating gear to efiect two degrees of yielding resistance to the rotation thereof, one of said degrees of resistance being greater, and the other being less than the resistance efiected by said pawl.

4. A photographic printing device comprising a light source having an exposure aperture, 8. pivotally mounted film magazine reciprocable between printing and non-printing positions with respect to said aperture, a rotatable gear mounted independently of said magazine, means associated with said gear to yieldingly resist rotation thereof in one direction and to prevent rotation thereof in the opposite direction, a mating gear carried by said magazine meshing with said independently mounted gear, means operatively connected with the mating gear and the film for feeding the latter, and means associated with said mating gear to efiect two degrees of yielding resistance to the rotation thereof, one of said degrees of resistance being greater, and the other being less than the resistance effected by said means associated with the independently mounted gear.

CHARLES P. GARMAN.

Images