Photographic Exposing Apparatus

Abstract

A photographic exposing apparatus which includes a housing, a light source within the housing and a drum carrying a light-sensitive plate and photographic film past the light source to expose the plate through the film. The plate and film are both registered to the drum and held by suction to the drum while provision is also made for locking the plate to the drum. The housing contains air deflecting means for directing a flow of cooling air to the region between the light source and the drum and then for exhausting the air to remove any gases or dust from the housing. A masking shield is provided between the drum and the light source, and it cooperates with the air deflector means to define air flow passages for directing the cooling air to the region between the drum and the light source.

Description

This invention relates to a photographic exposing apparatus for exposing the light-sensitive surface of a plate through a photographic film.

In the photographic exposing apparatus of the present invention a light source is accommodated within a housing and a rotating drum carries the plate and photographic film in registered positions thereon past a light zone within the housing to expose the light-sensitive surface for a predetermined period of time before returning the plate to the loading and unloading station.

One of the objects of the present invention is to provide means for quickly locking and registering the plate and film on the rotatable drum to facilitate the loading and unloading operations.

Another object of the invention is to provide a safe enclosure for the light source to prevent injury to the eyes of the operator.

Still another object of the present invention is to provide an effective air cooling and exhaust system for the interior of the housing to prevent damage to the plate and photographic film and to safely remove dirt and toxic zone.

These and other objects are achieved in the photographic exposing apparatus of the present invention by providing cooperating registering pins and preformed holes to register the plate and film on the drum, suction means to hold the plate and film on the drum during the operating cycle of the machine, a mask interposed between the drum and the light source to limit the light rays to the zone of the drum which carries the plate and film, and an air supply and exhaust system in which filtered air is directed toward the plate and film during exposure for cooling purposes and then exhausted to remove ozone and dust.

For a complete understanding of the invention reference should be made to the detailed description which follows and the accompanying drawings in which:

FIG. 1 is a side elevational view of the photographic exposing apparatus of the present invention with a portion of the side housing broken away;

FIG. 2 is a front elevation of the apparatus with a portion of the front housing broken away;

FIG. 3 is an enlarged fragmentary front elevation of part of the apparatus shown in FIG. 2 with part of the housing broken away;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3 looking in the direction of the arrows;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 4 looking in the direction of the arrows;

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 5 looking in the direction of the arrows;

FIG. 7 is a fragmentary front view of the apparatus showing the drum with a sensitized printing plate and photographic film mounted thereon; and

FIGS. 8 and 9 are sectional views taken along the line 8-8 and 9-9, respectively, of FIG. 7 looking in the direction of the arrows.

The photographic exposing apparatus of the present invention, as best shown in FIGS. 1 and 2, includes a lower housing 10 for accommodating various mechanical and electrical equipment, an upper housing 11 for accommodating the photographic exposing apparatus, and a hood 12 which connects an opening at the top of the upper housing 11 with a conduit 13 in communication with a blower (not shown).

The upper housing 11, as best shown in FIG. 4, accommodates therein a bank of exposure lights 14 mounted on a common support 15, at least part of a rotatable drum 16 which carries a light-sensitive surface to be exposed past the bank of exposure lights 14, a masking shield 17 intermediate the bank of exposure lights 14 and the rotating drum 16 and having a rectangular aperture 18 therein defining a light zone through which the light rays pass to expose the light-sensitive surface carried by the drum 16, and a pair of air deflectors 19 mounted on opposite sidewalls of the housing 11 behind the masking shield 17 to direct air introduced into the housing 11 between the shield 17 and the air deflectors 19 toward the opening 18 of the masking shield to cool the light-sensitive surface of the drum 16.

The rotatable drum 16 is supported on a rotatable shaft 20 which rotates in bearings 21 mounted to opposite sidewalls of the housing 11. The shaft 20 is driven by a motor 22 (see FIG. 2) through a clutch 23, a gear box 24, a sprocket 25 driven through the gear box, and a chain 26 which meshes with the sprocket 25 and a sprocket 27 mounted on the shaft 20. The clutch 23 is disengaged after each cycle of operation to stop the drum in the loading and unloading position.

In the normal operation of the photographic exposing apparatus, the drum 16 carries a plate 28, for example, a nylon printing plate, having an outer light-sensitive surface 28a, and a photographic film 29, such as a hard dot and line film negative, through which the light-sensitive printing plate is to be exposed. To facilitate the loading of the plate 28 and the film 29 on the drum, the drum is only partially enclosed within the housing 11, and part of the outer periphery of the drum remote from the part that is exposed to the lights 14 is accessible to the operator through an opening 30 in the front of the housing 11. The portion of the drum 16 outside the housing 11 serves as a loading and unloading station at which the operator can load and unload the plates and films.

The photographic exposing apparatus of the present invention incorporates means for mounting the light-sensitive plate 28 and photographic film 29 on the drum quickly and in proper registration. The plate 28 is accommodated within a recessed portion 31 defined between a pair of curved segments 32 affixed circumferentially to the drum. The plate receiving recess 31 is located outside the housing 11 when the drum is in loading position. The recessed portion 31 accommodates a curved plate clamp 33 (see FIGS. 3 and 4) which is mounted to the drum by a pivot 34. The photosensitive plate 28 is relatively rigid and its curvature corresponds with the curvature of the drum 16 so that it seats on the outer periphery of the recessed portion of the drum. The side edges of the plate 28, as best shown in FIG. 9, are dovetailed and flare outwardly at 28b so that they interlock at one edge with the complementary shaped edge of one of the segments 32 and at the opposite edge with the complementary shaped edge of the clamp 33. The outer edge of the free end of the plate clamp 33 carries a spring urged lock 35 which engages a recess 36 in the inner side edge of the other of the segments 32 to lock the clamp in plate clamping position.

Since the side edge clamping means for the plate 28 will normally afford some freedom of movement to the plate, the back surface of the plate is provided with a hole which engages a registering pin 37 with close tolerance (see FIG. 8) so that the plate will be registered with precision on the drum. The registering pin 37 and the complementary curvatures of the plate and the drum prevent the blank from rotating about the pin to provide precise registration of the plate with respect to the drum.

The film 29 is registered with precision with respect to the drum 16 and the plate 28 by providing prepunched aligning holes along the side edges of the film which engage registering pins 38 (see FIG. 7) projecting outwardly from the segments 32. When the plate 28 is mounted to the drum, the outer light-sensitive surface 28a thereof is substantially in the same circumferential plane as the outer surfaces of the clamp 33 and the segments 32. The photographic film 29 is wider than the underlying plate 28, and when the punched holes in the side edges of the film are engaged with the pins 38, the film is in perfect registry with the plate 28 and the drum.

The plate 28 is held by suction in intimate contact within the recessed portion 31 of the drum, and the film 29, in turn, is held by suction in intimate contact with the light-sensitive surface 28a of the plate 28. Toward this end, the outer surface of the recessed portion 31 of the drum has formed thereon, as best shown in FIG. 3, a connected network of longitudinal and circumferential channels 39 which are connected to a vacuum pump 40 (see FIGS. 1 and 2) mounted in the lower region of the housing 10. The channels 39 are connected to the vacuum pump 40 through a pair of conduits 41, a coupling 42 on the shaft 20 connecting the conduits 41 to an axial passage 43 in the shaft, and a coupling 44 which connects the axial passage 43 to a flexible house or conduit 45 connected to the intake of the vacuum pump.

The drum rotates in a counterclockwise direction, as viewed in FIG. 8. To insure that the leading edge of the film 29 is held in contact with the drum, the upper or leading edge thereof is inserted under a protective plate 46 when the film is loaded on the drum. The protective plate is affixed to the drum by screws 47.

A vacuum gauge 48 is connected to the vacuum hose or conduit 45 through a conduit 49 to indicate the vacuum pressure.

The masking shield 17, as best shown in FIG. 4, is a curved mask closely spaced from the outer periphery of the drum 16 and has a curvature which corresponds to the curvature of the drum. The masking shield is supported at its upper end to a bracket 50 affixed by bolts 51 to a mounting 52 connected to the underside of the top of the housing 11. At its lower end the masking shield is supported by a bracket 53 affixed by bolts 54 to a plate 55 separating the housings 10 and 11. The brackets 50 and 53 are adjustable horizontally to control the spacing between the masking shield 17 and the outer periphery of the drum 16.

The air deflectors 19 are supported by adjustable plates 56 (see FIG. 4) to the sidewalls of the housing 11. The plates 56 are connected to the sidewalls of the housing 11 by bolts 57 which engage slots 58 in the plates 56. The passages 59 between the deflectors 19 and the masking shield 17 taper inwardly, as best shown in FIG. 6, to direct cooling air toward the opening 18 of the masking shield.

Air to cool the interior of the housing 11 and to remove toxic ozone therefrom is introduced into the housing 11 through louvers 60 in the sidewalls of the housing 11, passes through fiberglass filters 61 accommodated in louvered housings 62, is directed by the passages 59 toward the opening 18 in the masking shield 17 to cool the plate and film, and then passes upwardly through the interior of the housing 11 to remove ozone, dirt and dust from the housing 11 through the hood 12 and the exhaust conduit 13 to the intake of a blower (not shown). A thermostat 63 in the conduit 13 regulates the speed of the blower.

The spacing of the air deflectors 19 from the masking shield 17 regulates the air intake into the housing 11 to cool the plate and the film. This spacing can be adjusted by adjusting the position of the masking shield 17 toward and away from the drum and by adjusting the positions of the air deflectors 19 toward and away from the mask.

The exposure lights 14 are mounted to the support 15 by clamps 64. The support 15 is adjustable toward and away from the drum 16 to regulate the intensity of the exposure light. Also, the support 15 is rotatable about a lower pivot 65 (see FIG. 4) to permit the support to swing rearwardly when the back plate 11a is removed to permit replacement of the exposure lights 14.

The shaft 20 carries a series of control cams 66 which actuate microswitches 67 to control the automatic cycle of the machine. An exposure indicator 68 and translator 69 are accommodated within the upper region of the lower housing 10 to regulate the speed of rotation of the drum as a function of the exposure light intensity so that constant exposure will be obtained regardless of the light intensity.

The lower region of the housing 10 accommodates a bank of transformers 70, in addition to the vacuum pump 40. The lower region of the housing 10 is cooled and heat is dissipated through the louvers 71. A fiberglass filter 72 is mounted adjacent each of the louvers 71 to prevent dust and dirt from entering the housing.

A window 73 is mounted in the hood 12 so that the operator can observe whether the exposure lights 14 are functioning.

In the operation of the photographic exposure apparatus of the present invention, a photosensitive plate 28, such as a nylon printing plate having a light-sensitive surface 28a, and a photographic film 29, for example, a hard dot and line negative, are mounted within the recessed portion 31 of the drum which is accessible to the operator through the opening 30 in the housing 11. The plate clamp 33 is raised to the position shown in FIGS. 3 and 4, and the plate is placed on the drum with one of the dovetail portions 28b engaging the complementary surface of the segment 32 opposite the clamp 33 and the hole in the back of the plate registered on the pin 37. The pivotal clamp 33 is then locked to clamp the other dovetail portion of the plate onto the drum.

The photographic film 29 is then placed on the drum with its leading edge tucked under the flap or plate 46, and the prepunched holes are engaged on the pins 38 protruding from the segments 32. Suction is then applied to the network of channels 39 in the recessed portion 31 of the drum 16, holding both the plate 28 and the photographic film 29 securely to the drum.

The drum 16 is driven through its cycle of operation, carrying the photographic film 29 and the light-sensitive plate 28 past the light zone defined by the opening 18 in the masking shield 17 to expose the light-sensitive surface through the photographic film.

The air intake into the housing 11 through the filtered louvers 60 directs a flow of air between the masking shield 17 and the air deflectors 19 to direct the air into the center region of the housing 11 and against the plate and film exposed to the light zone of the masking shield 17. The flow of air also passes the exposure lights 14 and then is exhausted through the hood 12 and the conduit 13 for the elimination of ozone and dust from the housing 11.

The invention has been shown in preferred form and by way of example only, and obviously, many variations and modifications may be made therein without departing from the spirit of the invention. The invention, therefore, is not to be limited to any specified form or embodiment, except insofar as such limitations are set forth in the claims.

Claims

We claim:

1. A photographic exposing apparatus for exposing a light-sensitive surface of a plate through a photographic film comprising a housing, a light source within the housing, a rotatable drum carrying said plate and photographic film into the path of the light rays of said light source within the housing, locking means for locking the plate to the drum, means for registering the plate on said drum, means for registering the photographic film on the drum in overlying relation with respect to the plate, and suction means communicating with the drum for holding said plate in engagement with the plate registering means before it is locked to the drum and for holding the said photographic film on the drum in engagement with the film registering means.

2. A photographic exposing apparatus as set forth in claim 1 in which the drum includes a recessed portion for accommodating the plate therein.

3. A photographic exposing apparatus as set forth in claim 2 in which said recessed portion includes means engageable with edges of the plate.

4. A photographic exposing apparatus as set forth in claim 1 in which said locking means includes a pivotally mounted curved locking means which in raised position permits insertion or removal of the plate and in locking position holds the plate to the drum.

5. A photographic exposing apparatus as set forth in claim 2 in which the suction means communicates with the recessed portion to hold the plate and film therein.

6. A photographic exposing apparatus as set forth in claim 1 in which the means for registering the plate on said drum includes complementary hole and pin means for registering the plate with the drum.

7. A photographic exposing apparatus as set forth in claim 1 in which said means for registering the photographic film on the drum includes complementary hole and pin means for registering the film with the drum.

8. A photographic exposing apparatus as set forth in claim 1 including a masking shield between the drum and the light source and having an opening therein to form a limited light zone to expose said plate through said film.

9. A photographic exposing apparatus as set forth in claim 1 including air intake means for admitting air into the housing, air deflecting means to direct the flow of air toward the portion of the drum carrying the plate to be exposed, and air exhausting means to exhaust air from the housing.

10. A photographic exposing apparatus as set forth in claim 8 including means for adjusting the spacing between the masking shield and the drum.

11. A photographic exposing apparatus as set forth in claim 9 including means for adjusting the spacing between the masking shield and the air deflecting means.

12. A photographic exposing apparatus as set forth in claim 9 in which said means for admitting air into the housing includes a filter.

13. A photographic exposing apparatus for exposing a light-sensitive surface of a plate through a photographic film comprising a housing, a light source within said housing, a rotatable drum partially accommodated within said housing for carrying said plate and film from a plate and film loading and unloading station outside the housing into exposure with said light source, air intake means in the housing, air deflector means for directing the air intake toward the exposed area of the drum to cool the plate and the film, air exhaust means communicating with the space between the light source and the drum for exhausting air from the housing, plate and film loading and unloading means on said drum, and an opening in said housing for exposing said plate and film loading and unloading means of said drum so that the plates and films can be loaded and unloaded from said drum outside the housing.

14. A photographic exposing apparatus as set forth in claim 13 including a masking shield within said housing intermediate the light source and the drum and defining a limited light zone for exposing the plate through the film.

15. A photographic exposing apparatus as set forth in claim 13 including means for clamping the plate to the drum and suction means for holding the plate and the film to the drum.

16. A photographic exposing apparatus as set forth in claim 13 including pin and hole means for registering the plate and film on the drum.

17. A photographic exposing apparatus comprising a housing, a light source within the housing, a rotatable drum mounted within said housing for carrying a light-sensitive surface to be exposed to the light rays within the housing, a masking shield interposed between the drum and the light source and having an opening therein for producing a light zone on a portion of the drum, air intake passage means for admitting air into the housing, air deflector means for directing the flow of air admitted into the housing toward the portion of the drum exposed to the light source, said air deflector means and the masking shield cooperating to define air flow passages directed toward the portion of the drum exposed to the light source, and air exhaust means communicating with the space between the light source and the portion of the drum exposed to the light source for exhausting air from the housing.

18. A photographic exposing apparatus as set forth in claim 17 in which the air deflector means is intermediate the light source and the masking shield and including means for adjusting the spacing between the air deflector means and the masking shield.

19. A photographic exposing apparatus as set forth in claim 17 including means for adjusting the spacing between the masking shield and the drum.