GB2181853A

GB2181853A - Registered film advance

Info

Publication number: GB2181853A
Application number: GB08524788A
Authority: GB
Inventors: Martin Terence David Howard; Wilfred Irwin
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-10-08
Filing date: 1985-10-08
Publication date: 1987-04-29
Anticipated expiration: 2005-10-08
Also published as: GB2181853B; GB8904688D0; GB2212932A; GB8524788D0; GB2212932B

Abstract

Images are projected in sequence from cine film 12 passing stepwise through enlarger head 10 to photographic paper 50 passing stepwise over base board 40. On stepwise advance of the film, which is threaded through first sprocket wheel 18/nip roller 20, pair of apertured plates 22/24 and second sprocket wheel 26/nip roller 29, plates 22/24 are raised thereby releasing the film from stationary registration pins 30 and engaging the film with registration pins 34 which advance with the film and then return to their original position. The photographic paper is engaged by a punch (52, Fig. 3) during exposure, enabling the paper to be registered in the same position at a later time. The apparatus may be used in making cartoon films. <IMAGE>

Description

SPECIFICATION Photographic apparatus and methods This invention relates to photographic apparatus, and in particular, but not exclusively, to apparatus for use in making cartoon films. The invention also relates to methods of forming photographic prints.

In one form of cartoon film, a cine film is taken which forms the background of the cartoon film, and then cartoon characters are formed, frame by frame, on the cine film. One method of overlaying the cartoon characters is termed "aerial image". By that method, the background cine film is projected, frame by frame, through a transparent plate located at the focal plane of the projector into a camera which is focused on the plate, and cartoon characters are disposed on the plate so that they too are photographed by the further camera. A disadvantage of the aerial image method is that the cartoonist/operator cannot see an image of the background film at the plate, and therefore it is difficult to locate the cartoon characters correctly relative to the background, and furthermore it is difficult to ensure the correct contrast between the cartoon characters and the background.

There is a further known method of overlaying the cartoon characters on the background.

By this other method, a enlarger is used to form a print of each frame of the background film, and the cartoon characters are disposed on the prints and then re-photographed. More specifically, the background film is manually mounted on a carrier which is loaded into a enlarger head and one frame is projected onto a sheet of photographic paper on the enlarger table to expose the paper. The carrier is then removed from the enlarger head and the film is manually moved so that the next frame can be projected; a fresh sheet of paper is placed on the table, and the process is repeated. It will be appreciated that these steps must be repeated several thousand or many thousand times for a cartoon film of reasonable length.

One problem of this latter method is ensuring correct registration of the background film in the enlarger head and correct registration of the paper on the enlarger table. If registration is not perfect or extremely close to being perfect, then flicker will arise in the end product.

In the past, in an attempt to provide proper registration, the carrier has been provided with pins which are a close fit in the sprocket holes in the background film, and the sheets of paper are punched and fitted onto pins on the enlarger table. When the processed paper is overlayed with the cartoon characters, it is also at that stage fitted onto pins on a table on which the camera is mounted, and preferably the cartoon characters are drawn on transparent sheets which are also punched and fitted onto the pins when the background print and cartoon character are re-photographed.

Registration errors can still occur, however.

The sprocket holes in the background film may not be a perfect match for the pins on the film carrier for the enlarger head, and it may be difficult to ensure perfect registration of the carrier with the enlarger head. Furthermore, the punch holes in the paper may not be a perfect match for-the pins on the enlarger table, or the re-photographing table, and air may become trapped between the paper and enlarger table when the paper is mounted on the table, causing the projected image to be out of focus on the paper.

Various aspects of the present invention aim to alleviate at least to some extent some of the above mentioned disadvantages of the known method described above.

In accordance with one aspect of the present invention, there is provided an enlarger the head of which has means to guide a sprocket-holed film therethrough, a drive to advance the film stepwise through the guide, and means to move the film and a registration pin relative to each other after each step to engage the pin with a sprocket-hole in the film to register the film with the enlarger head.

Thus, the film is registered directly with the enlarger head rather than indirectly with a registration pin which can be moved relative to the head. Futhermore, since the film is advanced stepwise through the guide without the necessity for unloading and re-loading the film between frames, any errors in registration (for example due to the sprocket holes not being a perfect match for the registration pin) compared with the intended position of the film tend to occur repeatedly in such a way as to cancel themselves out.

In accordance with another aspect of the present invention, a means (such as a punch) is provided to form registration means on the paper whilst the paper is located on the enlarger table, and the paper is exposed whilst the paper is so located. Thus, the means by which the paper can later be registered is defined at the time the paper is exposed, and therefore no registration error can occur between the paper and enlarger table.

Preferably, the enlarger table forms part of a 'roll-box' arrangement in which paper is fed from a supply reel and across the table to a take-up reel. Thus, a series of prints (for example, 500) are made on a single roll of paper. This provides a couple of significant advantages. Firstly, the prints are formed on the paper in the same order as the frames on the background film, and the roll can be cut and numbered after the roll has been processed, thus avoiding the problem in the known method of inadvertently mixing up the order of the sheets of paper in the dark room.

Secondly, because the paper is drawn across the table from one reel to the other, there is less risk of air being trapped between the pa per and table and causing focusing problems.

Further features and advantages of the invention will become apparent from the following description, given by way of example, of an embodiment of the invention, reference being made to the accompanying drawings, in which: Figure 1 is a schematic side elevation of the registration and advance mechanisms in the enlarger head; Figure 2 is a plan view of part of the registration mechanism; and Figure 3 is a perspective view of the enlarger table.

Referring to Figure 1, the enlarger head has a chassis, part of which is indicated by reference numeral 10. A cine film 12 is guided through the enlarger head and over an aperture 14 in the chassis member 10. Light from a source 16 passes through the film 12, the aperture 14 and a lens system 16 and is focused on an enlarger table, disposed below the enlarger head.

In its travel through the enlarger head, the film 12 passes between a first driven sprocket wheel 18 and associated nip roller 20, then between a pair of apertured plates 22, 24 which sandwich the film 12 therebetween, and then between a second driven sprocket wheel 26 and associated nip roller 28. The guide plates 22, 24 are formed with apertures, as shown in Figure 2, so that light can pass therethrough. A pair of registration spigots 30 are mounted upright on the chassis member 10 and project through holes in the guide plates 22, 24. Furthermore, an advance member 32 is provided having a pair of downwardly directed advance spigots 34. The guide plates 22, 24 are mounted for movement in an up and down direction. The advance member 32 is mounted for movement to right and left (as viewed in Figure 1) and the registration spigots are stationary.

As shown in Figures 1 and 2, the registration spigots 30 engage a pair of sprocket holes in the film, and thus the film is registered in the enlarger head. Furthermore, the advance spigots 34 are aligned with a further pair of sprocket holes in the film.

A motor driven advance mechanism (not shown) is provided which drives the sprocket wheeis 18, 26, the guide plates 22, 24 and the advance member 32 in the following manner in order to advance the film by one frame.

Firstly, the guide plates 22, 24 are raised as indicated by arrows 1 to disengage the registration spigots 30 from the film and to engage the advance spigots 34 with the aligned sprocket holes in the film. Secondly, the advance member 32 is moved to the right and the sprocket wheels 18, 26 are rotated clockwise in order to advance the film by approximately one frame, as indicated by arrows 2. Thirdly, the guide plates 22, 24 are lowered as indicated by arrows 3 in order to reengage the registration spigots 30 with different sprocket holes in the film. Lastly, the advance member 32 is returned to the left as indicated by arrow 4. Thus, the next frame on the film 12 is registered. In order to assist engagement of the registration spigots 30 and advance spigots 34 with the sprocket holes in the film, the free ends of the spigots are domed or tapered.

Once the film has been advanced, the light source 16 can be operated to expose photographic paper on the enlarger table below the enlarger head, and then the film can be advanced by a further frame.

The drive mechanism can be provided with a facility for reversing the direction of advance, and in that case the movements indicated by the arrows in Figure 1 are carried out in the order 2, 1, 4, 3.

Preferably, a counter is provided which is incremented or decremented with advances of the film in one direction or the other.

Referring now to Figure 3 of the drawings, the enlarger table has a base board 40 on which is mounted a support 42 for the enlarger head. A known form of roll-box arrangement is also mounted on the base board 40 and comprises a light-proof housing for a supply reel for a roll of photographic paper and a further light proof housing 46 for a take-up reel for the photographic paper. The take-up reel is motor driven, the motor being controlled by a control module 48 which includes amongst other things a facility for controlling the amount of stepwise advance of the paper.

The paper may be about 1 foot (300 millimetres wide) and the portion 50 of the paper between the supply housing 44 and the takeup housing 46 extends flat across the base board 40, in a position where it can be exposed by light directed from the enlarger head supported on the post 42.

A punch 52 is mounted at the front of the base board 40 and is arranged such that upon operation of an actuating lever 54 the punch 52 punches three holes in the edge of the portion 50 of the photographic paper on the base board 40. The three holes which are punched may have a standard format with a central circular punch hole and to either side thereof a slot-shaped punch hole.

In operation, the punch is operated by depressing the lever 54, and whilst the lever is maintained in a down position the light source in the enlarger head is operated to expose the portion 50 of the paper. The lever 54 is then released, and the pins of the punch are raised by spring pressure to release the portion 50.

The motor is then operated to rotate the takeup reel to advance the paper from the supply reel to the take-up reel, and the film is advanced in the enlarger head. The process is then repeated.

The punch 52 may be arranged to locate the paper portion 50 in position merely by the punch pins, or alternatively a clamp may be actuated by the punch lever 54 to hold the paper portion 50 in position whilst the punch pins are punched through the paper and until after the paper has been exposed.

The punch lever 54 may be operated by a solenoid which is automatically controlled together with the motor for the take-up reel and the drive mechanism for the film feed in the enlarger head so that the enlarger may be completely automated.

It will be apparent that various other modications may be made to the enlarger. For example, rather than punching holes in the paper, it may be sufficient to cut notches in the edge or, indeed, to cut the roll of paper on the enlarger table so that the cut edge can be used for subsequent registration of the paper.

In this specification, the word "enlarger" is not necessarily intended to mean that the equipment can produce an enlarged image of the film frame, since by suitable arrangement of the lenses in the enlarger, a reduced image could be produced with the arrangement still possessing the advantages of the arrangement described above. Furthermore, the words "photographic paper" are intended to cover photo-sensitive photographic recording media of other types.

Although the invention was conceived for use in making cartoon films, it will be apparent that the invention may be used in other applications where it is desired to produce a series of registered prints or the like from a series of frames on a photographic film.

Claims

1. A photographic enlarger having an enlarger head which includes means to guide a sprocket-holed film across the light path of & the enlarger, a drive to advance the film stepwise through the guide, and means to move the film and a registration spigot relative to each other after each step to engage the registration spigot with a sprockethole in the film to register the film with the enlarger head.

2. An enlarger as claimed in claim 1, wherein the registration spigot is fixed stationary relative to the enlarger body, and the film is moved to engage the registration spigot with a sprocket-hole in the film.

3. An enlarger as claimed in claim 2, wherein the guide means is moved to engage the registration spigot with a sprocket-hole in the film.

4. An enlarger as claimed in claim 3, wherein the guide means is moved prior to a step advance of the film to disengage the registration spigot from a sprocket-hole in the film and is returned after a step advance to engage the registration spigot with a different sprocket-hole in the film.

5. An enlarger as claimed in any preceding claim, wherein the guide means has portions to extend over either side of the film to sandwich the film therebetween.

6. An enlarger as claimed in any preceding claim, which has two such registration spigots to engage sprocket-holes along respective edges of the film.

7. An enlarger as claimed in any preceding claim, wherein the advance drive includes an advance spigot which engages a sprocket-hole of the film during a step advance of the film and moves to draw the film through the guide means.

8. An enlarger as claimed in claim 7, wherein the guide means is moved to engage the advance spigot with a sprocket-hole in the film.

9. An enlarger as claimed in claim 8, wherein the guide means is moved prior to a step advance of the film to engage the advance spigot with a sprocket-hole in the film and is returned after the step advance to disengage the advance spigot from thatsprocket-hole.

10. An enlarger as claimed in any of claims 7-9, wherein the advance spigot is moved in a direction opposite to that of film travel after the step advance for advance of the film in one direction through the guide means, and is moved in that direction prior to the step advance for advance of the film in the opposite direction.

11. A method of forming a photographic prints from the frames of a sprocket-hoied film, wherein the film is advanced stepwise through an enlarger head and after each step advance at least one sprocket-hole of the film is engaged with a registration pin to register the film in the enlarger head.

12. A photographic enlarger having a table for photographic paper to be exposed, means to locate the paper relative to the table, means to form registration means on the paper whilst the paper is located by the locating means, and means to expose the paper whilst the paper is so located.

13. An enlarger as claimed in claim 12, wherein the means to form registration means on the paper is a punch for punching holes in' the paper.

14. An enlarger as claimed in claim 13, wherein the punch also serves to locate the paper relative to the table.

15. An enlarger as claimed in any of claims 13-14 wherein the table forms part of a rollbox arrangement in which paper is fed from a roll on a supply reel and across the table to a take-up reel.

16. An enlarger as claimed in claim 15, further comprising means for advancing the paper step-wise across the table.

17. An enlarger as claimed in claim 16, further comprising means for automatically operating the registration forming means after the paper has been advance.

18. An enlarger as claimed in any of claims 12-17, and also having the features of any of claims 1-10.

19. An enlarger as claimed in claim 18 when dependent on claim 17, further comprising means for automatically exposing the paper by way of the enlarger head after operation of the registration forming means, and automatically advancing the film through the enlarger head when the paper is not being exposed.

20. An method of forming photographic prints with an enlarger, wherein each print is formed with a registration means before exposure by the enlarger and is not moved until after exposure.

21. A photographic enlarger substantially as described in the description with reference to the drawings.

22. A method for use in making a cartoon film, substantially as described in the description with reference to the drawings.