Claims
- 1. An improved writing and display device for producing a semi-permanent luminescent image upon the application of a writing pressure thereon comprising
- a rigid backing member formed of an inexpensive cardboard material,
- said backing member having a smooth, opaque surface,
- a transparent thin film of a plastic material,
- said transparent film being ultra thin with a thickness in the range of 0.001 to 0.0005 inches and said ultra-thin film being adhesively secured to the opaque surface of said backing member,
- a transparent plastic sheet containing a luminescent tinting material integrally dispersed throughout said plastic sheet,
- said tinted transparent plastic sheet being disposed in overlying relationship to said transparent thin film,
- said tinted transparent plastic sheet and said transparent thin film each having a smooth surface for direct contact at the interface thereof,
- and said tinted transparent sheet being pliable so that upon the application of a pressure thereon, the respective smooth surfaces of said transparent sheet and transparent film are urged into intimate contact at the points of applied pressure to form a luminescent image along the points of applied pressure that will be retained thereon so long as said transparent tinted sheet and said transparent film are adhered to one another along the points of applied pressure, said luminescent image being erased by effecting separation of said tinted transparent sheet and said ultra thin film,
- said ultra thin film adhesively being secured to said backing member operating to minimize any electrostatic charge produced between said transparent sheet and underlying film during separation thereby eliminating any build-up of dust on the interfacing surfaces thereof,
- said thin film being selected from the group consisting of polyethylene, polypropylene and polyvinyl.
CROSS-REFERENCES TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 07/315,611, filed Feb. 27, 1989, now U.S. Pat. No. 4,927,748.
The present invention relates to a writing and display device for producing semipermanent luminescent images.
Conventional writing and display devices include a translucent or transparent sheet which contains a luminescent dye and a complementary opaque sheet which is disposed contiguous adjacent to, and coextensive with, the translucent or transparent sheet. Upon application of a pressure by means of for example a stylus or the like, the two sheets tend to adhere to one another along the points of applied pressure to produce a luminescent image. The translucent or transparent sheet as well as the complementary opaque sheet are made of plastic material, usually vinyl. Writing and display devices of this type are disclosed for example in U.S. Pat. No. 3,761,343 or 4,011,665.
As it is generally known, an electrostatic charge is produced on the surface of a plastic when it is separated from another surface. The static charge increases as the plastic is handled and attracts dust particles. It has been observed in prior art display devices of the above type, that the build up of static charges and the attraction of dust particles resulted in images in form of clusters, dots or lines even though no outside pressure was applied. This effect could be observed within a relative short time so that the playing value of the display device deteriorates rapidly to a point where the device was no longer interesting or amusing.
A further problem encountered with prior art display devices of this type relates to the manufacture of the game. The coextensive sheets are usually made of pliable vinyl material. Vinyl is, however, a material which is difficult to handle in a machining process because of its flexible properties so that consistent quality of the sheets is difficult to attain and assembling of the device becomes a problem.
It is thus a general object of the present invention to provide an improved writing and display device obviating the afore-stated drawbacks.
This object and others which will become apparent hereinafter are attained in accordance with the present invention by coating an opaque backing member to render it with a smooth surface and laminating the smooth surface of the backing member with an ultra thin substantially transparent flexible sheeting made of plastic material. A substantially transparent plastic sheet is disposed contiguous to the backing member and in interfacing relationship therewith and has a luminescent tinting material dispersed therethrough so that upon application of pressure on the plastic sheet a luminescent image is formed at the points of applied pressure.
Suitably, the backing member is rigid and may be coated with a shellac which provides the backing member with a smooth surface. The sheeting applied on the smooth surface of the backing member is an ultra thin film of a thickness preferably in the range of approximately 0.0005 to 0.001 inch and may suitably be made of polyethylene, polypropylene or polyvinyl or any other suitable material.
By laminating the backing member with such an ultrathin, substantially transparent film, the electrostatic charge is considerably decreased than in prior art devices which use two overlying vinyl sheets. Moreover, the manufacture of the display device is considerably facilitated as the film is applied on a rigid backing member which may be of any suitable material.
According to a further feature of the present invention, the translucent or transparent plastic sheet is formulated with a primary plasticizer that resists migration, exudation or volatilization out of the surface of the plastic sheet, e.g. vinyl sheet under normal or storage conditions. Transparent sheets employed in conventional display devices used luminescent dyes which showed a tendency to migrate or bleed out of the plastic sheet onto the underlying opaque sheet. In a relatively short period of time, the underlying opaque sheet would absorb the migrated dye and assume the color thereof, resulting in a loss of the brilliance of the images. The formulation of the transparent sheet with a primary plasticizer, preferably a primary low volatile plasticizer, obviates this migrating effect.
US Referenced Citations (5)
Continuation in Parts (1)
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315611 |
Feb 1989 |
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Patent Grant
4988301
