Post plastic lens photographic slide mount

A post plastic lens photographic slide mount made from a plastic slide mount includes a first and second plastic frame portions connected along an outer border with a pocket into which a photographic film slide can be inserted. A top plastic lens and a bottom plastic lens that can be introduced to the plastic slide mount. The plastic lenses can be added at the same time the photographic film slide is inserted into the plastic slide mount, or the lenses may be added after the plastic slide mount has been assembled. The lenses are held in place by a tongue and groove arrangement.

CROSS-REFERENCE TO RELATED APPLICATION(S) 
None. 
BACKGROUND OF THE INVENTION 
The present invention relates to a slide mount for mounting film 
transparencies from a photographic film web to prepare a photographic 
slide. In particular the present invention allows for plastic lenses to be 
added to the photographic slide after it has been assembled. 
Photographic film transparencies are generally severed from a photographic 
film web and mounted in individual slide mounts to prepare photographic 
slides. The photographic image of the prepared photographic slide is then 
viewed in cooperation with a slide projector or other visualizing means. 
Plastic slide mounts, such as the Pakon slide mount sold by Pakon, Inc., 
are generally formed of first and second plastic frame portions connected 
along an outer border to form a pocket therebetween. The slide mount 
includes a central aperture defined by film windows formed in each of the 
first and second frame portions. Further, the slide mount includes a slit 
along the outer border which defines an insertion opening through which a 
photographic film transparency can be inserted into a pocket between the 
first and second frame portions, creating a photographic slide. 
A photographic slide is susceptible to several events that can adversely 
affect its quality. Fingerprints or other debris can mark or scratch the 
film as a result of handling. In addition, when exposed to the heat of a 
slide projector, the film may expand and buckle, causing the projected 
image to go out of focus. 
In response to the adverse conditions listed above, the slide mounting 
industry has come up with glass slide mounts. Such glass slide mounts 
protect the film from excessive heat and serve to keep the film flat and 
thus the projected image in focus. In addition, glass slide mounts protect 
the film from fingerprints or other debris that could mark or destroy the 
film. A major problem with glass film mounts, however, has been that they 
arc expensive and very slow to assemble. At present, glass lenses are 
added to a slide mount by hand. Another problem is assuring the film and 
mount are cleaned before the glass lenses are added to the slide mount so 
that dust or other particles do not get trapped between the film and 
lenses. 
Thus there has been a continuing need for a slide mount system that 
manifests the benefits of glass mounts, i.e., holding the film flat when 
exposed to heat and protecting the film from fingerprints and other 
debris, while at the same time allowing for assembly in an inexpensive, 
quick manner that allows for the film and slide mount to be cleaned before 
the lenses are added. 
BRIEF SUMMARY OF THE INVENTION 
The present invention offers an inexpensive and quick manner of adding 
slide mount lenses after a photographic slide has been assembled. The post 
plastic lens slide mount begins with a plastic slide mount in which the 
photographic film slide has been mounted. The plastic slide mount is made 
from plastic that is sufficiently flexible to allow the slide mount to be 
pried apart slightly so that a photographic film slide can then be 
introduced. This slide mount has a central aperture through which the 
mounted photographic film is then visible. 
While there arc many ways to hold the lenses in the slide mount, in one 
preferred embodiment, the central aperture has a shaped inner edge. This 
shaped inner edge allows for a plastic lens to be introduced and held in 
the slide mount. The plastic lens has a correspondingly shaped edge which 
allows it to mate with the inner edge of the central aperture of the slide 
mount, thus holding the plastic lens in place. In this manner, both a top 
lens and a bottom lens can be added to the slide mount, thus protecting 
the photographic film. In creating the post plastic lens slide mount, film 
is loaded into the slide mount to prepare a photographic film slide. The 
mount and the film are then cleaned using air pressure. Top and bottom 
plastic lenses are likewise cleaned using air pressure, and are then 
inserted into the plastic slide mount. It is possible to mount these 
plastic lenses at the same time the plastic slide mount is being 
assembled, or the plastic lenses can be mounted into the slide after the 
film has been inserted. In other words, a consumer can choose to have the 
plastic lenses added to the mounts when the consumer gets the slides made, 
or the consumer can wait and add the lenses at a later time.

DETAILED DESCRIPTION 
FIG. 1 is a perspective view of a slide mount 10 of the present invention. 
The slide mount 10 is formed of a first frame portion 12 and a second 
frame portion 14 and includes a central aperture 16 and a slit 18. The 
slit 18 allows for a film transparency to be slidably introduced into the 
slide mount 10. This is achieved by applying a separating force to 
opposing camming surfaces 20 and 22, as illustrated by arrow 26, to 
separate the first and second frame portions 12 and 14. The first and 
second frame portions 12 and 14 are formed of a resilient plastic material 
that allows them to be flexed apart when the separating force is applied 
at camming surfaces 20 and 22. When this separating force is released 
after a film transparency is inserted, the first and second frame portions 
12 and 14 close to form the photographic slide mount. 
The first and second frame portions 12 and 14 each have a film window that 
together create a central aperture 16 when the slide mount 10 is 
assembled. An image on a film transparency becomes visible through this 
central aperture 16. It is this central aperture 16 to which post mount 
plastic lenses are added. 
FIG. 2 is an exploded cross-sectional view taken along line 2--2 of FIG. 1. 
FIG. 2 shows a top lens 30 which can be introduced into the second frame 
portion 14. Also shown is a bottom lens 32 which can be introduced into 
the first frame portion 12. The top and bottom lenses 30 and 32 may be 
coated with a scratch resistant material so that the lenses 30 and 32, 
even when exposed to other surfaces, remain transparent and free of 
scratches or mars. Likewise the lenses 30 and 32 may consist of an 
antihalation surface to eliminate newton rings and improve the ability to 
view the film transparency. 
The lenses can be held in the slide mount in a variety of ways. For 
instance, a layer of adhesive can be used to hold the lens and slide mount 
together. Similarly, the lenses can be held in place with a series of pins 
and holes or notches. Any method used must result in the outer surfaces of 
the lenses being essentially flush with the top and bottom surfaces of the 
slide mount frame portions such that the finished slide can still be used 
in standard slide projectors and slide holders. 
In one embodiment, the top lens 30 and bottom lens 32 are held in place 
because the inner edges of the first and second frame portions 12 and 14 
are shaped such that a tongue 36 mates with the shaped outer edges of the 
lenses 30 and 32 at groove 38. FIGS. 3 and 4 show an exploded side view of 
a portion of the lens mount along with this tongue and groove system. FIG. 
3 shows that the slide mount tongue 36 on first frame portion 12 is made 
up of a first vertical mount surface 41, a top sloped mount surface 42, a 
second vertical mount surface 43, and a bottom sloped mount surface 44. 
Similarly, the slide mount tongue 46 on second frame portion 14 has a top 
sloped mount surface 51, a first vertical mount surface 52, a bottom 
sloped mount surface 53, and a second vertical mount surface 54. The lens 
groove 38 on top lens 30 is made up of a first vertical lens surface 61, a 
top sloped lens surface 62, a second vertical lens surface 63, and a 
bottom sloped lens surface 64. Likewise, the lens groove 48 on bottom lens 
32 has a top sloped lens surface 71, a first vertical lens surface 72, a 
bottom sloped lens surface 73, and a second vertical lens surface 74. The 
slide mount tongues 36 and 46 continue around the entire outer edges of 
the lenses 30 and 32. In like manner, the lens grooves 38 and 48 continue 
around the entire inner edges of the central aperture 16 of both the first 
and second frame portions 12 and 14. 
FIG. 4 shows how, once introduced, the mount tongue 36 and lens groove 38 
fit together. The lens grooves 38 and 48 are coupled with the mount 
tongues 36 and 46 such that the vertical and sloped surfaces of the lenses 
fit snugly against the vertical and sloped surfaces of the mount. This 
coupling can be achieved by applying a force to the lenses 30 and 32 until 
they snap into place in the slide mount 10. The film 34 fits between the 
top plastic lens 30 now coupled with the top mount surface 12 and the 
bottom plastic lens 32 now coupled with the second frame portion 14 
leaving room for the film to expand and contract as it is exposed to heat. 
FIG. 5 is a flow diagram setting out the process for fitting a plastic 
slide mount with plastic lenses. First step 80 is to prepare a 
photographic film slide by loading a film into a slide mount. As 
previously explained, this can be done by applying a separating force to 
opposing camming surfaces 20 and 22 shown on FIG. 1, sliding a film into 
the resulting opening, and then releasing the force. 
Second step 82 is to clean the combined mount and film by using anti-static 
air pressure to remove any dust or debris. Cleaning by anti-static air 
pressure is a practice well known to those skilled in the art. Third step 
84 is to provide top and bottom plastic lenses. In fourth step 86, the top 
and bottom plastic lenses are also cleaned by using anti-static air 
pressure. The fifth step 88 is to insert the top and bottom plastic lenses 
into the slide mount. As mentioned, this can be achieved in several ways. 
In a preferred embodiment, the lenses are inserted by applying a force to 
the lens until it snaps into the slide mount. The lens remains inserted in 
the slide mount because, as previously described, the lenses are coupled 
with the slide mount using a tongue and groove arrangement running around 
the central aperture 16. 
Although the present invention has been described with reference to 
preferred embodiments, workers skilled in the art will recognize that 
changes may be made in form and detail without departing from the spirit 
and scope of the invention.