US20030037473A1

US20030037473A1 - Apparatus for displaying a transparency

Info

Publication number: US20030037473A1
Application number: US10/197,140
Authority: US
Inventors: Jeffrey Pifer
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-08-21
Filing date: 2002-07-17
Publication date: 2003-02-27

Abstract

An apparatus for displaying a transparency includes a Fresnel lens panel and a support structure. The support structure supports the transparency on a horizontal surface in an upright viewing position, and supports the Fresnel lens panel in a position behind the transparency. In this configuration, light passing through the Fresnel lens panel from the rear of the Fresnel lens panel is directed through the transparency for viewing of the transparency.

Description

This application claims the benefit of U.S. Provisional Application No. 60/313,863 filed Aug. 21, 2001.[0001]

FIELD OF THE INVENTION

The present invention relates to an apparatus for viewing a transparency, and particularly relates to an apparatus for displaying a transparent photographic image.

BACKGROUND OF THE INVENTION

A transparency may be displayed for viewing in an upright position by placing the transparency on a stand or other supporting device. The supporting device uses back-lit illumination. Such devices typically provide uneven illumination of the transparency. This is most noticeable when a source of artificial illumination is used for back-lighting the transparency. In that case, a localized area of increased light intensity, referred to as a “hot spot,” appears on the transparency directly in front of the back-lit illumination source. The uneven illumination produced by the formation of the “hot spot” results in a decrease in light intensity as the eye travels away from the “hot spot” toward the periphery of the transparency.

SUMMARY OF THE INVENTION

In accordance with the present invention, an apparatus for displaying a transparency includes a Fresnel lens panel and a support structure. The support structure is configured to support the transparency on a horizontal surface in an upright viewing position. It is further configured to support the Fresnel lens panel in a position behind the transparency. In this configuration, light passing through the Fresnel lens panel from the rear of the Fresnel lens panel is directed through the transparency for viewing of the transparency.

In a preferred embodiment of the invention, the support structure further includes a translucent diffuser panel. The support structure is configured to support the diffuser panel in a position behind the transparency. The support structure is further configured to support the Fresnel lens panel in a position behind the diffuser panel. In this configuration, light passing through the Fresnel lens panel from the rear of the Fresnel lens panel is directed first through the diffuser panel and subsequently through the transparency for viewing of the transparency.

In the preferred embodiment, the support structure is a frame surrounding and positioning the individual layers of the apparatus which include the Fresnel lens panel, the diffuser panel, the transparency, and a transparent front panel. The support structure is further configured to surround and define the periphery of the viewable area of the transparency. Light is directed uniformly through the viewable area of the transparency by the Fresnel lens panel which extends completely across the viewable area.

In another embodiment of the invention, a source of artificial light is used to direct light rays into the back of the Fresnel lens panel. The Fresnel Lens panel redirects the light through the layers of the apparatus in a uniform manner, thereby eliminating the “hot spot” that otherwise might be observed when a source of artificial light is used to back-light a transparency display.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a first preferred embodiment of the present invention; [0008]
FIG. 2 is a front view of a part shown in FIG. 1; [0009]
FIG. 3 is a view taken on line [0010] 3-3 of FIG. 2;
FIG. 4 is a side view of the first embodiment; [0011]
FIG. 5 is a side view of a second preferred embodiment of the present invention; and [0012]
FIG. 6 is an enlarged sectional view, taken from the side, of a part shown in FIG. 5.[0013]

DESCRIPTION OF PREFERRED EMBODIMENTS

An [0014] apparatus 10 comprising a first preferred embodiment of the present invention is shown in FIG. 1. The apparatus 10 includes a picture frame structure 12 which supports a transparency 14 in an upright position for viewing. Light entering the back of the apparatus 10 passes through the transparency 14 resulting in back-lit illumination of the transparency 14. The apparatus 10 produces uniform illumination across the entire viewable area 16 of the transparency 14, and also brightens the transparency 14.
As shown partially in FIG. 1, the [0015] apparatus 10 has a number of layers enclosed in the frame 12. In the preferred embodiment, there are four layers enclosed within the frame 12 which are as follows: 1) a Fresnel lens panel 18 forming the back of the apparatus 10, 2) a diffuser panel 20 positioned in front of the Fresnel lens panel 18, 3) the transparency 14 containing the image to be viewed, and 4) a transparent front panel 22 forming the front of the apparatus 10.
As best shown in FIGS. 2 and 3, the Fresnel [0016] lens panel 18 in the first preferred embodiment is formed from a rectangular piece of plastic having a front side surface 24 and a back side surface 26. The front and back side surfaces 24 and 26 are bounded by upper and lower edge surfaces 28 and 30 and opposite end edge surfaces 32 and 34. An array of Fresnel lens grooves 35 extends across the back side surface 26 from the center 36 of the back side surface 26 outward to the peripheral edge surfaces 28, 30, 32, and 34. Although the plastic Fresnel lens panel 18 in this embodiment has grooves 35 arranged as concentric circles, a glass Fresnel lens panel would preferably have the grooves in a rectangular configuration. The back side surface 26 of the Fresnel lens panel 18 with the grooves 35 forms the back of the apparatus 10 with the front side surface 24 facing toward the front of the apparatus 10. It might be preferable to reverse the orientation of the panel 18 so that the grooves 35 face toward the front of the apparatus 10 to protect the plastic grooves 35 from physical damage.
The next layer of the [0017] apparatus 10 is the diffuser panel 20 which is positioned within the frame structure 12 immediately in front of the Fresnel lens panel 18 such that the diffuser panel 20 and the Fresnel lens panel 18 are adjoining in overlying surface contact fully throughout areas extending with the viewable area 16. The diffuser panel 20 is formed from a translucent material, such as frosted glass, and is of the same size and shape as the Fresnel lens panel 18.
The [0018] transparency 14 to be viewed is the next layer of the apparatus 10 and is positioned immediately in front of the diffuser panel 20 within the frame structure 12 such that the transparency 14 and the diffuser panel 20 are adjoining in overlying surface contact fully throughout areas extending with the viewable area 16. The transparency 14 is formed from a piece of translucent material having a viewable image. However, the transparency can have any other structure suitable for viewing in the apparatus 10. For example, the transparency can be a piece of photographic film or can be printed from an ink jet or laser printer.
The final layer of the [0019] apparatus 10 is a transparent panel 22, preferably formed from a clear pane of glass or plastic with the same size and shape as that of the Fresnel lens panel 18. The transparent panel 22 is positioned directly in front of the transparency 14 within the frame structure 12 and forms the front of the apparatus 10. The transparent panel 22 functions to protect the transparency 14 from dust and physical abrasion.
As shown in FIG. 1, the [0020] frame structure 12 enclosing the layers of the apparatus 10 has a rectangular configuration defined by an upper 37, a lower 38, a left 39, and a right 40 channel. The channels 37-40 are preferably made from a metal material, and are joined at their ends at right angles to give the frame structure 12 its rectangular configuration in which the upper 37 and lower 38 channels are parallel and opposite each other, and the left 39 and right 40 channels are parallel and opposite each other. The joined channels 37-40 of the frame structure 12 receive and surround the Fresnel lens panel 18, diffuser panel 20, transparency 14, and transparent panel 22 layers as shown in FIG. 1. The frame structure 12 thus defines and surrounds the periphery of the viewable area 16.
As shown in FIG. 4, the [0021] frame structure 12 in the preferred embodiment is held upright in a free standing position on a horizontal surface 44 by a support member 46 affixed to the back of the frame 12 and extending out from the frame 12. The support member 46 can have any suitable configuration known in the art.
When light rays are directed toward and through the [0022] apparatus 10 from the back, the light rays passing through the Fresnel lens panel 18 toward the front of the apparatus 10 are directed by the array of Fresnel lens grooves 35 from the panel 18 further through the apparatus 10. The lens panel 18 then functions to enhance the illumination of the viewable area 16 in accordance with the configuration and orientation of the grooves 35, as well as the index of refraction of the material from which the Fresnel lens panel 18 is formed. The light transmitted from the Fresnel lens panel 18 must first pass through the diffuser panel 20 and subsequently through the transparency 14 and transparent panel 22 before reaching the viewer. The function of the diffuser panel 20 is to provide a bright white opalescent background for any clear or colorless areas of the transparency 14. In addition, the translucent quality of the diffuser panel 20 prevents the array of Fresnel lens grooves 35 from being visible through the transparency 14. Thus, the overall effect produced by the apparatus 10 in viewing the transparency 14 is that the apparatus 10 produces even illumination across the entire viewable area 16 of the transparency 14 thereby providing uniform edge-to-edge brightness over the entire viewable area 16 of the transparency 14.
As shown in FIG. 5, a second preferred embodiment of the invention further includes a [0023] reflective cushion panel 52 which overlies the horizontal surface 44 beneath the apparatus 10. FIG. 6 shows that the reflective cushion panel 52 preferably has a laminate structure which includes a paper layer 54 overlaid with a layer of compressible foam 56 which in turn is overlaid with a paper layer 54. Each paper layer 54 of the reflective cushion panel 52 has a reflective outer surface 58. FIG. 4 shows how the apparatus 10 is to be positioned upon the reflective cushion panel 52.
When the apparatus is configured as in FIG. 5, the [0024] reflective cushion panel 52 directs light falling behind the apparatus 10 upward toward the rear side of the apparatus 10 where the light rays can then enter and pass through the Fresnel lens panel 18. The reflective cushion panel 52 therefore functions to increase the amount of light transmitted through the transparency 14 for increased illumination of the transparency 14.
The embodiment of the invention as shown in FIG. 5 further includes a source of artificial light [0025] 60 (shown schematically) for additional illumination of the transparency 14 by the apparatus 10. Light rays emitted from the source of artificial light 60 are directed by the reflective cushion panel 52 into the back of the apparatus 10. The redirection of light by the apparatus 10 functions to eliminate a “hot spot” that might otherwise be observed when a source of artificial light is used to illuminate a transparency from behind. Thus, uniform edge-to-edge brightness is achieved across the entire viewable area 16 of the transparency 14 when the transparency 14 is viewed through the apparatus 10 using a source of artificial light 60 for illumination.
The invention has been described with reference to preferred embodiments. Those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications are intended to be within the scope of the claims. [0026]

Claims

1. An apparatus for displaying a transparency, said apparatus comprising:

a Fresnel lens panel; and

a support structure configured to support the transparency on a horizontal surface in an upright viewing position, said support structure being further configured to support said Fresnel lens panel in a position behind the transparency, such that light passing through said Fresnel lens panel from the rear of said Fresnel lens panel is directed through the transparency for viewing of the transparency.

2. An apparatus as defined in claim 1 further comprising a translucent diffuser panel, said support structure being further configured to support said diffuser panel in a position behind the transparency, and to support said Fresnel lens panel in a position behind said diffuser panel, such that light passing through said Fresnel lens panel from the rear of said Fresnel lens panel is directed first through said diffuser panel and subsequently through the transparency for viewing of the transparency.

3. An apparatus as defined in claim 2, wherein said diffuser panel and the transparency are adjoining in overlying surface contact fully throughout areas extending within said viewable area, and said diffuser panel and said Fresnel lens panel are adjoining in overlying surface contact fully throughout areas extending within said viewable area.

4. An apparatus as defined in claim 1 wherein said support structure surrounds and defines the periphery of a viewable area of said transparency, and said Fresnel lens panel extends throughout said viewable area to direct light through said transparency uniformly throughout said viewable area.

5. An apparatus as defined in claim 1 further comprising a reflective cushion panel configured to direct light upward toward the back of said Fresnel lens panel.

6. An apparatus as defined in claim 5 wherein said reflective cushion panel is a panel configured to overlay the horizontal surface, and has reflective opposite side surfaces.

7. An apparatus as defined in claim 6 wherein said reflective cushion panel has a compressible layer between said reflective opposite side surfaces.

8. An apparatus as defined in claim 1 wherein said support structure comprises a frame extending around the periphery of the viewable area.

9. An apparatus as defined in claim 1 wherein said Fresnel lens panel is a separate structure supported by said support structure.