GB2339102A

GB2339102A - Light emitting polymer (LEP) printer

Info

Publication number: GB2339102A
Application number: GB9827708A
Authority: GB
Inventors: Ignazio Barraco
Original assignee: Westwind Air Bearings Ltd
Current assignee: Westwind Air Bearings Ltd
Priority date: 1998-12-16
Filing date: 1998-12-16
Publication date: 2000-01-12
Also published as: GB9827708D0

Description

2339102 "Image Reproduction" The present invention relates to image

reproduction.

Now a well known method of image reproduction is to create one or more composite images as colour separations in sequential digital format by scanning, and then to print out the end product by the so-called image setting technique which uses rotary mirrors to scan the end medium (e.g. sensitive film or paper) with a modulated laser beam.

The present invention aims to provide a more convenient, and in many cases faster, method of reproducing images, particularly images to a high quality, as a replacement for the so-called image setting technique.

Now Light Emitting Polymers (LEPs) have been used for provision of visual images for display purposes and can now be manufactured in a sequential row or in a twodimensional matrix of lines to any size and thus an array of LEPs can be manufactured to a very high resolution. These are effectively LEDs using Polymers and can be made to glow at any frequency from infra red to UV including white light. The LEPs are manufactured to a specified 2 size and to a specified resolution resulting in a flexible sheet of plastic with edge connections which can be modulated through an interface to a Raster Image processor (RIP).

Accordingly the present invention provides a method of reproducing an image in which a sequential reproduction of the image, for example an electrical signal based on a raster of lines, is created, a matrix of light emitting polymers is provided on a carrier and arranged to be capable of being energised by a sequential modulation to provide an image, the matrix is brought into contact with a light sensitive reproduction medium and the matrix is energised by a sequential modulation dependent on the sequential reproduction of the image to provide an image on the reproduction medium.

The sequential reproduction of the image conveniently is an analogue or digital electrical signal produced by scanning of an image or it can be produced in other known ways such as by use of a digital camera.

The result can be an image representative of a page or pages from a desk top publishing system which can be reproduced on any suitable media such as film, plate, 3 printing drum, paper, either directly or indirectly via an intermediate image (such as a negative for a photograph).

The representative image on the LEP array will contain an image of a varying light intensity depending on which colours it is representing at any given time. For example if film was being used as the media and the final printing process was cyan, magenta, yellow and black (CKYK) then the LEP array would be modulated as cyan, magenta, yellow and black separations onto four separate pieces of film each one being imaged with varying intensities so as to represent the amount of the respective individual colours to make the final image.

In the case of known desk top publishing systems and raster image processing this is usually done automatically.

Thus, the invention uses an array of light emitting 20 polymers for the purpose of image reproduction, rather than merely for visual display.

It is now possible by the manufacture of high resolution LEPs as a row or two-dimensional array of lines to achieve image reproduction. Resolutions necessary for 4 the various forms of printing vary enormously. For the graphic arts industry these resolutions need to be of the order of 144 lines per mm or higher. However resolutions of 96 lines per mm is acceptable in some cases. For other less critical applications such as news print, resolutions much less than this are used.

To achieve resolutions comparable with the various applications, existing methods of reproduction lend themselves to the manufacture of the masks to make the high-resolution LEP arrays. In other words we can use image setter technology to make the masks to produce the LEP array.

In use the LEP array is simply placed on top of the media to be exposed and the image is then enabled by modulation of its elements sequentially. In the case of an intermediate film, a piece of say lithographic rapid access film would lay flat on a surface. The LEP array would be placed on top of, or adjacent the film and the image enabled for a predetermined length of time. The film would then be processed in the normal way and the resulting image would be transferred to appear on the developed piece of film. Thus the final image transfer is taking place as a rapid contact printing process.

The LEP matrix can be supplied with a modulated signal and be caused to emit light in the appropriate colour (cyan, magenta, yellow etc.) for printing each appropriate colour. Of course printing with white light and appropriate filtration is also possible, that is the colour can be created in other ways than by causing the LEPs to glow in the selected different colours or the medium itself may be in the appropriate colour and be exposed by white light modulated by the appropriate 10 colour separation.

Other processes such as plate, drum, paper, etc. would be processed in a manner appropriate to that medium by direct or indirect methods but the proximity and method of the imaging using an LEP matrix would remain the same.

The LEP matrix effectively represents light emitters to a specified resolution. Each emitter represents a pixel within an image. The intensity of the emitter is controllable by the interface. Several images could be modulated onto the array each one representing a different colour or part of a final image.

For a complete multi-colour final image several images in different colours containing separate or similar 6 inf ormation can be used. In a simple monochrome say black/white version just one image would be necessary.

A schematic drawing is enclosed which shows how the 5 system operates.

A desk top publisher computer system and a raster image processor (see left hand box) provide a sequential image. This is fed via an interface to a light emitting array, so that at the appropriate times for exposing the end media and under control of the interface, the image can be energised on the light emitting array in the colour required. This image contacts the final media which may be film, paper or drum.

Claims

7 CLAIMS 1. A method of reproducing an image in which a sequential

reproduction of the image, for example an electrical signal based on a raster of lines is created, a matrix of light emitting polymers is provided on a carrier and arranged to be capable of being energised by a sequential modulation to provide an image in light, the matrix is brought into contact with a light sensitive reproduction medium and the matrix is energised by a sequential modulation dependent on the sequential reproduction of the image to provide an image in light and thereby to provide, in dependence on the image in light, an image on the reproduction medium.
2. A method according to claim I in which the sequential reproduction of the image is an analogue or digital electrical signal produced by scanning of an image.
3. A method according to claim I in which the sequential reproduction of the image is provided by use of a digital camera.
4. A method according to any preceding claim in 8 which the LEP array is formed by use of a modulated laser beam
5. A method according to any preceding claim in which the LEP array is placed on top of the media to be exDosed and the image is then enabled by modulation of the elements of the LEP array sequentially.
6. Apparatus for reproducing an image comprising means for providing a sequential reproduction of the image as an electrical signal based on a raster of lines, a matrix of light emitting polymers carried on a carrier and including means enabling the light emitting polymers to be energised by sequential modulation dependent on the sequential reproduction of the image to provide a light image, and means for providing an image on a reproduction medium dependent on the light image provided by the sequentially energised matrix.