US2917985A - Continuous printing device - Google Patents

Description

Dec. 22, 1959 D. E. WILLIAMSON CONTINUOUS PRINTING DEVICE Filed May 11, 1955 [nae/afar Jailed M'lkzimsam gym/ uoK/wwvu W7 flit" a.

United States Patent CONTINUOUS PRINTING DEVICE Donald E. Williamson, West Concord, Mass., assignor, by mesne assignments, to Kalvar Corporation, New Orleans, La., a corporation of Louisiana Application May 11, 1955, Serial No. 507,633

1 Claim. (CI. 95-75) The photographic technique that provides records in terms of areas consisting of a microdispersed, multiphasic scattering system (also known under the name of vesicular, bubble or scatter photography), utilizes photographic material which comprises a vehicle (on a suitable support or self-supporting) and therein a light sensitive agent which upon irradiation generates gas; diazo compounds which liberate nitrogen when exposed to light, are at the present time preferred for this purpose. The vehicle can be a specially compounded gelatin or synthetic. The light for exposing such material to an original or intermediate copy has to be fairly strong and should not considerably raise the temperature of the photographic copying stock. Upon exposure, this photographic material is subjected to a treatment which is usually referred to as development, in analogy with conventional photographic techniques, and which involves the raising of its temperature to a few hundred degrees.

Some of the objects of the present invention are to provide a continuous printing device which carries out the above mentioned steps of exposure and development rapidly, exactly, and conveniently, and in accordance with the basic principles that are essential for this type of photography, especially without subjecting the photographic stock to undue heating during exposure, to provide such a device which carries out the exposure as rapidly as possible with the light sources available at the present time, to provide apparatus of this type which carries out the exposure and developing steps automatica-lly, requiring a minimum of effort and thought from the operator, to provide an exposure device which can be utilized within continuous printing apparatus according to the present invention or separately, when it provides advantages not heretofore obtained, to provide-a heat developing device which can be utilized within continuous printing apparatus according to the present invention, but is also suited for use with other exposure devices, to provide apparatus of the above indicated type which is of optimum operational simplicity and reliability permitting the passing of the photographic stock and of a sheet to be copied, through the exposure and developing components to obtain a completed copy without intermediate handling of the material, and without requiring manual peeling of the original from the copying stock, and generally to provide an improved device of the above indicated type.

In summary, the substance of the main aspects of the invention is as follows.

According to the invention, apparatus for the exposure and heat development of photographic records comprises a drum mounted for rotatory movement; in close contact with the drum a translucent belt moving with the drum tov form an exposure nip region parallel to the axis of rotation of the drum, for holding photographic material that moves with the drum and the belt; a light source essentially covering the nip region for exposure of the material; heat development means extending along the discharging side of the exposure nip region, which Patented Dec. 22, 1959 development means includes a roller and a curved heating platen contacting the roller to form a development nip region essentially parallel to the exposure nip region; means for directing the exposed photographic material from the discharging side of the exposure nip region into the adjacent receiving side of the development nip region; and means for driving the drum and the roller at essentially the same circumferential speed.

According to another aspect of the invention, photographic exposure means are provided which comprise a rotatably supported exposure drum; a plurality of belt transport rolls supported for rotation on axes parallel to the drum and essentially on one side of the drum; an endless translucent belt wound around the drum and the rolls to form a nip region at the side of the rolls; a light box lined with reflecting material, containing an extended light source and opening towards the nip region to cover an appreciable portion thereof with radiation from the light source; and means for driving the drum and the belt. In a practically important aspect, the light box is subdivided into two portions parallel to the nip region, by means of a heat absorbing or reflecting plate, the portion towards the nip region having walls reaching close to that region and the other portion being reflecting and containing the lamp; one end of the box is open and on the other side is a chest supplied with cooling air that passes into both portions cooling them separately and discharging through the open end of the box.

According to yet another aspect of the invention, heat development means are provided which comprise a driven roller covered with resilient friction material such as for example felt; and a platen, heated to an adjustable temperature and concavely curved around the roll to form a heat development nip where photographic material is moved past the heated platen in firm contact therewith; the nip region of the platen is polished so that the friction covering of the driven roller will move the material therethrough.

The following description of a typical embodiment illustrates these and other objects, and aspects of the nature of the invention. This description refers to a drawing in which Fig. 1 is a front elevation of the embodiment herein described;

Fig. 2 is a rear elevation of the upper portion of the device shown in Fig. 1, with the lower frame portion omitted;

Fig. 3 is a side elevation seen from the right-hand or drive side of Fig. 1; and

Fig. 4 is a schematic cross section through the device illustrating its essential components and their operation.

This practical embodiment of a device according to the invention has the following principal components, namely an exposure nip Ne defined by a drum 11 and a transparent exposure belt 12 of the endless type, a set 14 of four transport rolls 14.1, 14.2, 14.3, and 14.4, which hold the belt 12 in tension against the cylinder 11, a light box 15, a developer nip Nd defined by a roller 41 and a platen 45, and a frame structure 17 mounted on a convenient base 18 and carrying the above enumerated components and various auxiliary devices, all of which will now be described in detail.

The exposure drum 11 is made of metal such as alumi num and it is idlingly pivoted on the frame portions 17.1, 17.2. The transport rolls, made from aluminum tubing, are similarly supported on frame plates 17.1, 17.2 and one of them, such as roll 14.1, is driven as will be explained hereinbelow. The translucent or transparent belt 12 is applied around the outside of the four rollers 12 and concavely over the'periphery of drum 1'1 adjacent to the rolls 14, as clearly indicated in Fig. 4.

'the lamp 27 (Fig. 3).

reflecting or absorbing material 33 which provides two - longitudinal compartments 26 and 31 both of which can be cooled by streams of air as will be described hereinbelow. The lamp housing proper, 26, has walls which are coated with suitable reflecting material or carry -mounted thereon reflector plates 26.1, 26.2 forming an angle in which is mounted a tubular high emission lamp 27 of the gaseous discharge type, by means of brackets 28, one on each of the frame plates 17, as shown in Fig. 3. These brackets carry the terminal clips 29 for On the other side of plate 33 is the second light box portion 31 with reflecting deflector walls 31.1, 31.2 reaching close towards the nip Ne to direct the light from the lamp 27 and from the reflectors 26 towards the exposure face of drum 11 and belt 12.

The transport roller 41 of the developing unit is made of aluminum tubing similar to the above described transport rolls 14, and it is covered with felt or similar material, indicated at 42, which material is resilient enough to cause its surface to make contact with the curved platen 45 at the developer nip region Nd, such as to press the photo-graphic material against the platen when the material is fed through the device as will be described below. The platen 45 is polished, and heated by means of a heating element of conventional design within the casing 47, the temperature of which is regulated by a conventional thermostat 49.

The heater casing 47 also carries a sheet directing device 51 consisting essentially of a strip 51.1 and clips 51.2 screwed thereto as indicated in Figs. 1, 3 and 4. It will be noted that the discharging end of nip Ne is located adjacent to the lower edge 51 of the developer casing and to the receiving end of the developer nip Nd; these components are so arranged that the exposed photographic stock is securely guided into the developer nip.

The above mentioned auxiliary equipment includes the following principal components.

A motor 71 drives, through a conventional torque convertor 72, a chain sprocket 73 whose chain 75 drives the sprocket 76 of the developer roller 41 with its felt cover 42. The chain 75 also drives the belt roll 14.1, advancing the belt 12 on the rolls 14. This drive is so arranged that drum 11 and belt 12, forming the exposure nip Ne, and the developer roller 41 forming with the platen 45 the developer nip Nd, move at the same circumferential speed.

The tubular lamp 27 of the high intensity gas discharge type, is supplied through terminal clips 29, by means of transformer 81 and capacitor 82, in well known manner.

A blower 85, driven by electric motor 86, discharges into a chamber 87, mounted on the frame panel 17.1 as indicated in Figs. 1 and 2. As mentioned above, the air blown into chamber 87 is discharged through the two compartments 26 and 31 of the light box 15, emerging on the side of panel 17.2 as indicated in Fig. 3.

An arrangement for tightening the belt 12 by means of one of the rolls is indicated in Fig. 3. This arrangement includes two springs 14.8, 14.9, attached at one end to the frame and attached on the other end to the sliding bearings of roll 14.4, which run in slots 17.8 and 17.9 of plates 17.1 and 17.2.

The roller 41 as well as the drum 11 and the belt 12 are of sufiicient length to accommodate the maximum size of the photographic material which is to be handled. As mentioned above, the roll 41 is covered with felt or similar material 42 which material is resilient enough to cause its surface to make contact with the heated platen 45 and to press the photographic material against the platen when it is fed through the developer. The friction between the layer 42 and the photographic sheets is sufliciently high as compared to that between the sheets and the polished platen 45, such as to carry the sheets securely through the developer nip.

The above described device operates as follows.

Prior to printing, the lamp 27 is started in well known manner. Exposure drum 11 with belt 12, and developer roller 41 are set into motion by starting motor 71 and setting the desired speed by means of drive 72; this speed will depend upon the photographic characteristics of the original and of the copying stock, and upon the type of the lamp 27. The blower is started in order to provide cooling air for the light box 15. Current is supplied to heater 47, thermostat 49 being set to maintain the temperature that is most favorable for the technique in question, which again depends upon the type of original and copying stock used and also upon the emission intensity and quality of the lamp 27. About 200 F. is a frequently used temperature.

The sheet to be copied, indicated at O of Fig. 4, and the printing stock indicated at S of the same figure are fed into the exposure nip Ne. They proceed together between the drum and the belt, past the light box 15 as bounded by walls 31.1 and 31.2. The tension provided by the device described above with reference to the springs 14.8, 14.9 as applied to roller 14.4, keeps the belt 12 taut and in tension against the cylinder, securing good contact between the two sheets along the nip Ne. The photographic stock is exposed without its temperature being substantially raised, due to the cooling air forced through the compartments 26 and 31, as above described. The air forced through channel 26 mainly carries off heat from the lamp, whereas the air flowing through channel 31 cools the material in the nip. The heat absorbing material of plate 33 assists in this respect.

After the proper exposure time, regulated as mentioned above, the two sheets now emerge from nip Ne, and are passed above the guide 51 into the developer nip Nd between the polished platen 45 and the developing roller 41. As above described, the developer roller 41 is driven at a circumferential speed equal to that of the belt 12 so that the sheets proceed smoothly through the device. The completed print P and the orig'nal O are then discharged, as indicated in Fig. 4. The diameter of the developing roller 41 is chosen to provide, with the given circumferential speed, an optimum development time. It will be evident that exposed photographic stock alone can be treated in the developer nip, if desired.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claim.

I claim:

Apparatus for the exposure and heat development of photographic records, comprising: a drum mounted for rotary movement; a plurality of transport rolls supported for rotation on axes parallel to, and essentially on one side of said drum; an endless translucent belt wound on said drum and said rolls to form an exposure nip region on the side of said rolls; a light box including an elongate lamp and a reflector extending along said exposure nip region for the irradiation of photographic material between said drum and said belt at said region; means between said light source and said drum and belt for blocking heat radiations while passing exposure light heat development means extending along the discharging side of said exposure nip region, including a roller covered with resilient friction material and mounted parallel to said drum for rotary movement, a curved polished platen contacting said roller to form a development nip region essentially parallel to and adjacent to said discharging side of said exposure nip region, and means for heating said platen; means for directing exposed photographic mater al from said discharging side of the exposure nip region References Cited in the file of this patent UNITED STATES PATENTS 744,039 Brown Nov. 17, 1903 8 Dalton Oct. 25, 1910 Thornton Apr. 24, 1917 Sheppard Oct. 9, 1934 Buskes June 6, 1950 Shore Sept. 19, 1950 Codichini et al Feb. 8, 1955 Herrick Mar. 8, 1955 Fairbanks July 2, 1957

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