Apparatus For Processing Recording Material

Abstract

An apparatus for processing dry silver recording material includes a heated first curved platen over which a continuous belt is driven to heat the belt before engaging the recording material, and a second heated curved platen over which the recording material and continuous belt pass. The second curved platen is heated by a plurality of heaters to maintain constant belt and platen temperature while the recording material is passing therebetween, ensuring uniform and fast development of the recording material.

Description

BACKGROUND OF THE INVENTION

Apparatus for processing dry silver recording materials are widely known and used in industry. one of the major problems associated with the prior art is the inability to quickly and uniformly bring the material being processed up to development temperature, then maintaining that temperature for the balance of the time the recording material is in the apparatus. Non-uniform temperature introduces streaks and spots on the material after development. Quick unit warm-up is necessary as it is impractical to continuously operate the apparatus.

To overcome the problems associated with processing of dry silver recording material, previous devices relied on a plurality of small resistive devices insulated from one another and also insulated from a metallic surface for heating the recording material. Another device to overcome the problem provided a directly heated platen which was uniformly heated by passing current through the platen from a power source. Although this latter means provide a quickly and uniformly heated platen, such current required an additional transformer for development.

SUMMARY OF INVENTION

The present invention overcomes the above disadvantages by providing an apparatus having therein a continuous belt which is driven over a first curved heated platen before engaging the recording material and carrying it over a second curved platen which is heated by a plurality of heaters. The heaters are operated independent of each other to maintain uniform development platen temperature. Belt tension and the curved platens keep the processing material therebetween.

Basically, a platen situated close to an input opening in the device is heated to a high temperature so that the recording material being carried by the continuous belt, the belt already at the high temperature, is brought to the required development temperature very fast. A further heater, independently controlled and spaced from said heater to heat the platen, also heats the platen, but mainly to the extent of maintaining the temperature required for development of the recording material. Therefore, both sides of the recording material being processed are raised to the same temperature simultaneously. This unique approach to the problem associated with prior art enables very fast and uniform development of the recording material.

It is therefore an object of the present invention to provide a new and improved apparatus for processing recording material which overcomes the disadvantages of the prior art.

It is another object of the present invention to provide a new and improved apparatus for processing recording material wherein both sides of the recording material is uniformly and constantly heated.

It is a further object of the present invention to provide a new and improved apparatus for processing recording material having therein a plurality of individually heated platens.

It is a still further object of the present invention to provide a new and improved apparatus for processing recording material having therein a continuous belt whereby the belt is a source of thermal energy.

Another object of the present invention is to provide a new and improved apparatus for processing recording material which is of simple design and minimum construction.

The foregoing and numerous other objects, advantages, and inherent functions of the present invention will become apparent as the same is more fully understood from the following description, which describes a preferred embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhausting nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and principles thereof and the manner of applying it in practical use so that they modify it in various forms, each as may be best suited to the conditions of the particular use.

DESCRIPTION OF DRAWING

The single FIGURE is a sectional view of the apparatus embodying the present invention.

DESCRIPTION OF INVENTION

The drawing illustrates the invention and shows the apparatus 1 for processing of dry silver recording materials. It should be noted that although dry silver recording materials are of primary interest, the apparatus is an image developer for thermally processed paper. The dry silver recording material, hereinafter referred to as paper 2, is transported along a selected path between an input opening 3 and an output opening 4. A continuous belt 5, made from an elastic material having a relatively high specific heat, a high coefficient of friction and capable of withstanding the temperature involved, is wrapped over a plurality of rollers 6, 7, and 8. Rollers 6 and 7 are the secondary and primary drive rollers respectively, while roller 8 is an adjustable idler.

A plurality of curved platens 9 and 10 are indirectly heated by a plurality of heaters 11, 12, and 13. These heaters are of the type commonly known as "sheet" heaters. The heaters are intimitely bonded to the curved platens by contact cement or high temperature adhesive using conventional techniques. Appropriately placed theromocouples (not shown) sense the actual temperature of the platens in the area of the individual heaters, which are made from a material having high thermal conduction characteristics such as aluminium. Conventional electronic control maintains the platens at the desired temperature.

The assembly may be of any desired or suitable width and enclosed in an insulating housing 14. To further minimize thermal losses, all supports and drive connections are made of material having a low thermal conductivity. In addition, openings 3 and 4 are kept narrow. Thus, the entire system is conservative of space and construction is kept simple.

In operation, drive rollers 6 and 7 are synchronized to each other and driven by conventional means (not shown) such as a belt driven by a motor to move continuous belt 5 such that the exposed paper 2 introduced between platen 9 and belt 5 with the emulsion side against the belt in the direction indicated by arrow A from opening 3 will be transported through the apparatus and exit at opening 4. The curvature of the platen 9 and the elasticity of the belt 5 combine to maintain intimate contact between the paper and heated belt and between the paper and heated platen, which causes the latent image to be developed.

Dependent upon the choice of material, the coefficient of friction between the belt and the emulsion side of the paper is greater than it is between the back of the paper and the platen. This effects transport; thus, the platens are polished which minimizes friction. Reducing friction, in turn, reduces power requirements of the platen heaters. Paper entering at opening 3 must be rapidly heated which requires the area around opening 3 to receive more thermal energy, say, than the area around opening 4. Thus, heater 12 has only to maintain the desired development temperature. Heater 13 and platen 10 maintain belt temperature slightly above the temperature of platen 9. This technique raises the temperature of the emulsion side of the paper to development temperature at a fast rate, and minimizes the need to maintain belt temperature by thermal conduction through the material being processed. Thus, paper warm-up time is minimized allowing higher speeds for a given length of platen 9.

While there has been shown and described the preferred embodiment of the present invention, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. For example, when high speed operation is not desired, heater 13 and platen 10 may be removed. Accordingly, the drive roller 6 may be used as an idler and the entire apparatus operated at an even lower power level. Therefore, the appended claims are intended to cover all such changes and modifications that fall within the true spirit and scope of the invention.

Claims

The invention is claimed in accordance with the following:

1. An apparatus for processing dry silver recording material, comprising:

insulated housing means having an input opening through which the recording material is introduced into said insulated housing means and an output opening out of which the recording material is extracted from said insulated housing means;

first platen means disposed in said insulated housing means extending from said input opening to said output opening along which the recording material moves;

heating means provided on said first platen means for heating said first platen means therealong for developing information on the recording material;

continuous belt means disposed in said insulated housing means;

roller means disposed in said housing means including input roller means adjacent said input opening, output roller means adjacent said output opening, and intermediate roller means between said input roller means and said output roller means, said continuous belt means movably mounted onto said input roller means, output roller means, and said intermediate roller means, said continuous belt means adapted to be moved via said roller means so that said continuous belt means engages said first platen means thereby frictionally moving the recording material along said first platen means;

second platen means disposed in engagement with said continuous belt means between said input roller means and said intermediate roller means; and

heater means provided on said second platen means for heating said second platen means which heats said continuous belt means above the temperature of said first platen means whereby said continuous belt means raises the temperature of the emulsion side of the recording material to development temperature at a fast rate.