Radiation imagery chemistry: process – composition – or product th – Post imaging processing – Developing
Reexamination Certificate
2000-12-06
2002-06-11
Schilling, Richard L. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Post imaging processing
Developing
C430S363000, C430S383000, C430S502000, C430S506000, C430S509000
Reexamination Certificate
active
06403292
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to photographic materials. In a preferred form it relates to a duplitized photographic reflection and transmission display material.
BACKGROUND OF THE INVENTION
It is known in the art that photographic display materials are utilized for advertising as well as decorative displays of photographic images. Since these display materials are used in advertising, the image quality of the display material is critical in expressing the quality message of the product or service being advertised. Further, a photographic display image needs to be high impact, as it attempts to draw consumer attention to the display material and the desired message being conveyed. Typical applications for display material include product and service advertising in public places such as airports, buses and sports stadiums, movie posters and fine art photography. The desired attributes of a quality, high impact photographic display material are a slight blue density minimum, durability, sharpness and flatness. Cost is also important, as display materials tend to be expensive compared with alternative display material technology such as lithographic images on paper. For display materials, traditional color paper is undesirable as it suffers from a lack of durability for the handling, photo processing and display of large format images.
Prior art photographic display materials historically have been classified as either reflection or transmission. Reflection display material typically is highly pigmented image supports with a light sensitive silver halide coating applied. Reflection display materials are typically used in commercial applications where an image is used to convey an idea or message. An application example of a reflection display material is product advertisement in a public area. Prior art reflection display materials have been optimized to provide a pleasing image using reflective light. Transmission display materials are used in commercial imaging applications and are typically backlit with a light source. Transmission display materials are typically a clear support with a light sensitive silver halide and an incorporated diffuser (to hide the “show through” of the lamps used to provide viewing illumination) or a substantially transparent support coated with a light sensitive silver halide emulsion which requires a diffusing screen to be placed behind the material as a means to obscure the “show through” of the lamps used to provide illumination to the media. Prior art transmission display materials have been optimized to provide a pleasing image when the image is backlit with a variety of light sources. Because prior art reflection and transmission products have been optimized to be either a reflection display image or a transmission display image, two separate product designs must exist in manufacturing and two inventories of display materials must be maintained at the photo-finishing printing site. Further, when the quality of the backlighting for transmission display material is diminished when for example, a backlight bums out or the output of the backlight decreases with the age, the transmission image will appear dark and reduce the commercial value of the image. It would be desirable if an image support could function both as a reflection and transmission display material.
Prior art transmission display materials use a high coverage of light sensitive silver halide emulsion to increase the density of the image compared to photographic reflection print materials. While increasing the coverage does increase the density of the image in transmission space, the time to image development is also increased as the coverage increases. Typically, a high-density transmission display material has a developer time of at least 110 seconds compared to a developer time of 45 seconds or less for photographic print materials. Prior art high-density transmission display materials, when processed, reduce the productivity of the development lab. Further, coating a high coverage of emulsion requires additional drying of the emulsion in manufacturing, which reduces the productivity of emulsion coating machines. It would be desirable if a transmission display material was high in density and had a developer time less than 50 seconds.
Prior art reflection photographic materials with a polyester base use a TiO
2
pigmented polyester base onto which light sensitive silver halide emulsions are coated. It has been proposed in WO 94/04961 to use opaque polyester containing 10% to 25% TiO
2
for a photographic support. The TiO
2
in the polyester gives the reflection display materials an undesirable opalescent appearance. The TiO
2
pigmented polyester also is expensive because the TiO
2
must be dispersed into the entire thickness, typically from 100 to 180 &mgr;m. The TiO
2
used in this fashion also gives the polyester support a slight yellow tint, which is undesirable for a photographic display material. For use as a photographic display material, the polyester support containing TiO
2
must be tinted blue to offset the yellow coloration, and this, in turn, results in a loss in desirable whiteness and adding cost to the display material.
Prior art photographic display material uses polyester as a base for the support. Typically the polyester support is from 150 to 250 micrometers thick to provide the required stiffness. Prior art photographic display materials are typically coated with light sensitive silver halide imaging layers on one side of the support. Exposure devices have been built to expose only one side of prior art display materials thus there is little concern for print platen design. For example, exposure devices that use a vacuum roll for holding the media during exposing typically employ slots for vacuum. These slots act as “black traps” (areas were exposing energy will be lost and have little secondary reflection) that in a duplitized emulsion system can result in uneven density of the backside image.
In U.S. Pat. No. 6,030,756 duplitized silver halide imaging layers are discussed for use as a display material. In U.S. Pat. No. 6,030,756, both the top and bottom images are exposed by exposing the top side silver halide imaging layers. The display material in U.S. Pat. No. 6,030,756 is capable of giving a good image when viewed in either reflection or transmission mode; however, the display material in U.S. Pat. No. 6,030,756 suffers from uneven backside image density when placed against a non-uniform reflecting platen.
In simultaneously filed Docket 80,701, U.S. application Ser. No. 09/731,354, titled “POLYOLEFIN BASE DISPLAY MATERIAL WITH TONE ENHANCING LAYER” is disclosed a method to improve the backside imaging efficiency by the addition of a tone enhancing layer in combination with an antihalation layer. This method employs a tone enhancing layer to avoid the problem of greatly diminished imaging efficiency of the backside emulsions that is associated with using an antihalation layer alone. Although the process produces pleasing product, it has been found that the maximum achievable density of the element when viewed in transmission mode is still lower than prior art transmission only display materials. This tends to make images look “flat” and desaturated in comparison to prior art transmission display materials. Further, use of high levels of reflective material in the tone enhancing layer can degrade the color reproduction of the transmission element because of an unwanted increase in blue Dmin. In order to compensate for the less than desired amount of transmission density, the amounts of silver, gel, and coupler can be increased on the backside of the element. However, as more of materials are used for the backside of the element, the total thickness of the coated element is increased, and the process sensitivity of the element is degraded.
PROBLEM TO BE SOLVED BY THE INVENTION
There is a continuing need for an improved product that will present a bright reflective image when viewed directly and also provide a sharp bright image of sufficien
Aylward Peter T.
Bell Eric L.
Bourdelais Robert P.
Budz Jerzy A.
Camp Alphonse D.
Eastman Kodak Company
Leipold Paul A.
Schilling Richard L.
LandOfFree
Duplitized display material with translucent support with... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Duplitized display material with translucent support with..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Duplitized display material with translucent support with... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2904458