DE19636235A1 - Method and device for recording information on thermally developable photographic material - Google Patents

Abstract

A process is disclosed for recording information by means of a recording radiation on photo-sensitive photographic material (7) that can be thermally developed. The material (7) is exposed on an element (3), preferably a drum, generating a latent image. The material (7) is then thermally developed by the same element (3), generating a visible image from the latent one.

Description

The invention relates to a method and an apparatus for recording Information on photosensitive, thermally developable photographic Material according to the preambles of claims 1 and 11.

A variety of techniques are known for recording information, based on different physical and chemical principles. A first group of such methods works on the basis of the so-called Thermal sublimation transfers. A dye carrier film is compared a recipient material at a precisely defined distance and heated point by point so that from the dye carrier film to the receiver color particles and thereby on the receiver material to the keep the desired information record.

Such a method and such a device is e.g. B. from the DE 38 17 625 C2 known. Chemical substances for such image recording Processes after thermal sublimation transfer are e.g. B. from the GB 2 083 726 A is known.  

A disadvantage of the thermal sublimation process is that it is very technical is agile to record information with high optical density. Such Requirements are particularly important when recording images in medical slides Gnostic admission procedure required. In such admission procedures So far, conventional photographic film has largely been used fen, which is exposed to visible light and then in a photographic Development process by means of liquid photographic processing baths leads.

Furthermore, so-called "direct thermal" recording methods have become known where information - especially image information - be recorded on heat sensitive material by this material is heated directly point by point. Either so-called thermal Printheads are used in which microscopic, heated Ele elements are mechanically applied to the heat-sensitive material or the heating by means of infrared heat radiation point by point on the war sensitive material is effected. For such thermal recording Processes are described, for example, in EP 685 760 A1 and in EP 707 978 A1 appropriate materials and procedures specified.

Finally, methods are known in which photographic, on silver salts based material first with a recording radiation - in particular with visible light - is irradiated, thus creating a latent image. This latent image, which is initially imperceptible to the human eye then - similar to the conventional photographic above Wet development process - fed to a development process, whereby final image that is perceptible to the human eye and stable over time is produced. In contrast to the wet development process, the Ent takes place development of the latent image in these so-called "indirect thermal"  Procedure, however, by heat. Such procedures are compared to the previous ones mentioned method advantageous because the recording of the latent Bil which can be done much more precisely with regard to a desired gray level than in the thermal sublimation process and the direct thermal process ren. It is also advantageous in the indirect thermal process that the desired optical density, d. H. the blackening on the recording material rial, in two stages and thus can be generated with high resolution. One On the one hand, density control can be controlled by the amount of light (i.e. by the intensity of light and the duration of the irradiation) in the formation of the latent image can be controlled and on the other hand, the generated density can follow the, thermal development process over the quantity, d. H. by the amount of Temperature and by the process time, which affects thermal development will. Compared to the conventional, wet developing photographic Processes have the advantage that no liquid substances are required.

The industrial applicability of such processes ranges from a wide variety Industries such as the printing industry, the output of information from Computers that enable image output in the medical field and so probably the recording of color images as well as the recording of black white images.

Methods, devices and suitable materials for such an indirect thermal process for recording information on photosensitivity Lich, thermally developable photographic material are for example known from EP 679 946 A1 and WO 95/30934.  

A disadvantage of the known methods and arrangements for thermally ent wrapable photographic materials is that they are relatively large, especially because they are upstream and downstream of the respective thermoprocessors have switched guide and cooling rollers.

On the other hand, they are becoming increasingly compact, especially in the medical field Devices required because there is usually a lack of space in hospitals and the number of image recording devices required is constantly increasing.

It is therefore an object of the invention to provide a method and an apparatus for drawing of information on thermally developable photographic measure specify material that allow relatively compact recording and To provide development devices.

Another object of the invention is a method and an apparatus for Record information on photosensitive, thermally developed barely photographic material to indicate the fastest possible image drawing enables. This task also arises particularly in the sick houses in the emergency area, in which diagnostic images are available as quickly as possible Must be available.

These tasks are described in the characterizing parts of the claims che 1 and 11 specified features of the invention solved.

According to the thermally developable photographic material exposed to both an element of the recording radiation and ther mixed developed. In a preferred embodiment, the holder or guidance of the recording material used a drum. The up Drawing material is in particular on the surface of the drum guided along its outer surface or even transported by the drum.  

The recording is preferably done with visible light, but it can also with other radiation, e.g. B. with infrared radiation or UV radiation. It creates a latent image in the recording material which Heat supply thermally ent at a predetermined development temperature is wrapped. This creates a visible, stable image over time drawing material generated.

In one embodiment, the recording material is heated to exposed to the recording radiation, which creates the latent image becomes. However, the temperature of the recording material should be below the development temperature. Then the material immediately ther mixed developed, whereby a visible image is generated from the latent image.

The invention leads on the one hand to the fact that more compact devices are built can by simultaneously guiding elements for the recording material Exposure and can be used for development.

The preheating of the material surprisingly leads to the fact that the ther mixable, photographic material can be exposed for a shorter time than in the already known methods in which the material is unheated drawing radiation is exposed. It has been shown that the Ma material is more sensitive to the recording radiation when heated.

The recording radiation is preferably generated with a laser, the Beam intensity modulated according to the information to be recorded becomes. This modulation can be carried out in a manner known per se with an acoustoopti modulator. The laser radiation can also be done directly using Modula tion of the diode current of a laser diode according to the image information be modulated.  

According to the invention, the recording material on one and the the same carrier element both exposed and thermally developed. The Erfin This makes it possible, in particular, to film the film on a single, common to both expose and develop the seed drum. The film becomes one applied to the surface of the heated drum and along a slow Scan recording direction moved. The exposure takes place between two exposures drawing rolls instead, then the film is in a relatively large order wrap angle over the drum or together with the drum into one Output area transferred. The temperature is during the beam recording of the film preferably in the range between 80 ° and 110 ° C. However, this is not a mandatory requirement. The film could also be on part of the drum exposed, which is colder than the other drum parts. Likewise, the Film are exposed so shortly after hitting the drum so that its Temperature during the recording is still far below that of the film predetermined development temperature.

In order to develop the film, it remains for a predetermined process time from 10 to 15 seconds in particular firmly connected to the drum surface. The Drum surface is heated to the development process temperature. This Temperature is preferably in the range between 110 and 130 ° C. The emul Sion side of the film is preferably from the Facing away from the drum surface.

The optical elements for modulating the recording beam include in a deflection mirror (polygon or oscillating mirror) known per se or other deflection units, such as a hologone disk or the like. Also are optically imaging elements in the beam path of the recording beam necessary.  

In the following, exemplary embodiments of the invention are explained using some Figures explained in more detail.

Show it:

Fig. 1 shows a recording device according to the invention and

FIG. 2 is an electronic block diagram of the device of FIG. 1.

In FIG. 1, a laser printer 1 is shown. It exposes image information with high resolution (e.g. 5000 × 5000 pixels) on photographic, thermally developable sheet film 7 . The film is transparent in the unexposed, developed state and opaque in the exposed, developed state with an achievable maximum density of over 3.5. In each case a single sheet of the sheet film 7 is removed from a film supply drawer 2 by a suction arrangement 24 from a film supply stack and fed to an exposure and development unit 25 .

The laser recorder 1 comprises film storage and transport units, an electronic control unit 10 , optical assemblies 11 and an exposure and development unit 25th Control and setting parameters of the laser printer 1 can be entered via an operating console 17 .

The core of the unit 25 is an exposure and development drum 3 . The surface 3 a of the drum 3 is heated by a heater 6 to a process temperature of about 123 ° C. The heater 6 may have electrically operated heating mats, in the drum surface 3 a integrated heating wires or other suitable heating elements. It is preferably connected to a control circuit so that the process temperature is kept as constant as possible. The drum 3 rotates in the direction of rotation A.

A sheet film 7 to be exposed, which includes an infrared sensitizer, is inserted along a guide plate 27 between the drum 3 and a pressure roller 26 . There, the film 7 is pressed against the surface 3 a of the drum and preheated for about 3 seconds until it reaches the area of a first exposure pressure roller 8 due to the drum movement. The film 7 points with its emulsion side away from the drum surface 3 a. The drum 3 is rotated in direction A by a drive. As a result, the film is moved in a slow-scan direction Y from the pressure roller 8 to the pressure roller 9 . The exposure of the sheet film 7 takes place between these two rollers 8 , 9 . For this purpose, a laser beam 12 is modulated in intensity in accordance with the image information to be recorded and directed onto the sheet film 7 . The laser beam 12 is generated in a laser 18 , which optionally consists of a laser diode, one of its solid-state lasers or a gas laser. The light of the laser beam 12 has a wavelength in the visible range which is adapted to the sensitometric sensitivity of the film 7 . In the case of a laser diode, the laser beam 12 is modulated directly by controlling the diode current. In the case of a gas laser as the light source, the laser beam 12 is modulated outside the laser 18 by means of an acousto-optic modulator (AOM) 19 . By means of a rotating polygon mirror 21 , the laser beam 12 is moved across the sheet film 7 line by line in a fast scan direction X perpendicular to the slow scan direction Y. Lenses 20 , 22 form the laser beam 12 so that it has a spot size of approximately 140 μm in the recording plane of the sheet film 7 .

After exposure, the sheet film 7 is thermally developed. The latent image generated by the exposure in sheet film 7 is developed by heat so that the exposed areas are permanently blackened. The sheet film 7 is rotated together with the drum 3 in the direction A for thermal development and thereby pressed against the drum by a pressure belt 4 . The pressure band 4 is to be held on tension rollers 5 at a certain tension. With the pressure belt 4 , a wrap angle of approximately 180 ° is generated on the drum 3 , through which the process time for thermal development is influenced. By changing the wrap angle, the process time can be changed depending on the recording material used. It is between 3 and 20 seconds for common, thermally developable recording materials. Another parameter for influencing or controlling the thermal process time is the rotational speed of the drum. Wrapping angle and speed of rotation of the drum are set so that the process time is approx. 15 seconds. After the thermal development, the sheet film 7 is output from the exposure and development unit 25 via cooling rollers 14 into a film exit nip and from there to a film tray 16 . The entire device is cooled by a fan 13 .

Fig. 2 is a block diagram showing the essential components of the electronic control unit 10 rule.

A central data transmission line (BUS) 30 enables data transmission between all electronic components. The image data are taken from an image source (computer, medical diagnostic device, or the like) via an input / output interface. They are converted into control impulses for the write controller 36 in the central computing unit 32 in accordance with film and device parameters. This acts on the laser 18 or on the acousto-optical modulator 19 . System data are stored in memories 33 . The drive circuit 35 controls all mechanical drives. The heating electronics 34 controls the heating of the drum 3 .

Exemplary embodiments of the invention have been described. It is clear that other exemplary embodiments can be specified immediately for the person skilled in the art, which achieve the effects of the invention. For example, instead of the outer drum used for development and recording also a Inner drum are provided in which both the exposure and the  Development of the film take place on the inner surface of the drum. Instead of Pressure tape can also be a variety of pressure rollers for pressing the Films to the heated drum surface. Finally, can the transport of the recording material instead of through the drum the pressure tape can be effected. The recording material is on the Drum held tight.

Claims (23)

1. A method for recording information on light-sensitive, thermally developable photographic material ( 7 ) by means of recording radiation, characterized in that the material ( 7 ) on one and the same element ( 3 ) is both exposed and thermally developed. 2. The method according to claim 1, characterized in that the element ( 3 ) is a drum. 3. The method according to claim 2, characterized in that the material ( 7 ) on the outside of the drum ( 3 ) is both exposed and developed. 4. The method according to any one of the preceding claims, characterized in that the material ( 7 ) is first heated, in the heated state of the recording radiation is exposed, whereby a latent image is generated and then thermally developed, whereby a visible from the latent Image is generated. 5. The method according to any one of the preceding claims, characterized in that a laser beam ( 12 ) is used as the recording radiation, the intensity of which is modulated in accordance with the information to be recorded. 6. The method according to any one of the preceding claims, characterized in that the material ( 7 ) over the drum ( 3 ), in particular through the drum ( 3 ), is moved along a so-called slow scan recording direction (Y). 7. The method according to any one of the preceding claims, characterized in that a film ( 7 ) with an infrared sensitizer is used as photographic material and that the film is preheated before it is exposed. 8. The method according to any one of the preceding claims, characterized records that the recording radiation is electromagnetic and in Wavelength range of visible light and / or in the infrared range lies. 9. The method according to any one of the preceding claims, characterized records that the temperature during the radiation recording in the loading range between 80 ° C and 110 ° C and the temperature during Ent winding is between 110 ° C and 130 ° C. 10. The method according to claim 4, characterized in that the emulsion side of the material ( 7 ) away from the drum surface ( 3 a) during the beam recording and during development. 11. The device voltage radiation for recording information on photosensitive, thermally developable, photographic material (7) with a Aufzeich, characterized by an element (3) to which the mate rial (7) as well as held or during exposure during development ge leads becomes. 12. The apparatus of claim 11 that the element ( 3 ) is a drum. 13. The apparatus of claim 12, the material ( 7 ) on the outside of the drum ( 3 ) is held or guided. 14. The device according to one of claims 11 to 13, characterized in that means ( 3 , 6 , 26 ) are provided by which the material ( 7 ) is heated before and / or during the radiation recording. 15. Device according to one of claims 11 to 14, characterized in that the heating means ( 3 , 6 ) comprise a drum ( 3 ) on which the material ( 7 ) is heated both during the radiation recording and for development. 16. The device according to one of claims 9 or 10, characterized in that a laser beam ( 12 ) is hen in the visible and / or in the infrared electromagnetic wavelength range as the recording beam. 17. The device according to one of claims 13 to 16, characterized by two pressure elements, in particular pressure rollers ( 8 , 9 ) which press the mate rial ( 7 ) to the drum surface ( 3 a), the recording beam ( 12 ) between the two Pressure rollers ( 8 , 9 ) hit the material ( 7 ) through. 18. Device according to one of claims 11 to 17, characterized by a deflection unit ( 21 ) which deflects the recording beam ( 12 ) in a so-called fast-scan direction (X) over the material ( 7 ), a drive ( 35 ), which moves the material ( 7 ) during exposure in a so-called slow scan direction (Y) and a controller ( 10 ) which acts on both the deflection unit ( 21 ) and the drive ( 35 ). 19. Device according to claims 11 and 18, characterized in that the drive ( 7 ) acts on the drum ( 3 ). 20. The apparatus according to claim 18, characterized in that the drum speed in the slow scan direction (Y) and the wrap angle of the drum ( 3 ) are adapted to one another, in particular controlled by the controller ( 10 ), that a predetermined Development process time for the material ( 7 ), in particular in the range between 3 and 20 seconds, is observed. 21. Device according to one of claims 14 to 20, characterized by means ( 14 ) for cooling the material ( 7 ) after development. 22. Device according to one of claims 11 to 21, characterized in that the material ( 7 ) is photographic film. 23. Device according to one of claims 12 to 22, characterized by a band ( 4 ) which wraps around the drum ( 3 ).