Light efficient display device

• US 4,215,501 A
• Filed: 12/21/1977
• Issued: 08/05/1980
• Est. Priority Date: 12/21/1977
• Status: Expired due to Term

• Current Assignee: Ten-O-One Incorporated
• Original Assignee: Ten-O-One Incorporated
• Inventors: Meijer, Leo
• Primary Examiner(s): Pitrelli, John F.
• Assistant Examiner(s): Skillington, G. Lee
• Application Number:
  US05/862,927
• Time in Patent Office: 958 Days
• Field of Search: 40/582, 40/559, 40/564
• US Class Current: 40/559
• CPC Class Codes: G09F 13/16 Signs formed of or incorporating reflecting elements or surfaces, e.g. warning signs having triangular or other geometrical shape

Abstract

This invention relates to a contrast maintaining means for use in display devices. The invention uses a substrate of synthetic paper having a light reflectance to light transmittance ratio which is in the order of 1 to 1. A substantially opaque coating material having a light reflection index near zero is deposited in the desired pattern upon the substrate so as to provide an information carrying display. The coated areas of the display neither transmit nor reflect a significant amount of light. When light reaches the display from behind the light transmitted through the substrate is of substantially the same intensity as the light that would be reflected from the substrate if the same light had reached the display from the front. The light reaching a viewers'"'"' eyes from the uncoated areas of the substrate is constant for nearly all lighting angles while substantially no light reaches the viewers'"'"' eyes from the coated areas of the display. The contrast ratio between the light coming to the viewers'"'"' eyes from the coated areas of the display and the light coming to the viewers'"'"' eyes from the uncoated areas of the display is virtually a constant ratio for any given lighting level of the display regardless of the directions of the light sources.

Claims

1. A light efficient display device comprising;

(a) a translucent substrate having a front and a rear surface said substrate having optical properties such that approximately one half of the light incident on one of the surfaces of the substrate will be reflected from that surface and approximately one half of the light incident on that one surface will be transmitted through the substrate and will be emitted from the other surface,

(b) indicia formed on the front surface of the substrate

(c) said indicia being a substantially opaque and non-reflective coating and

3. The light efficient display device of claim 1 wherein the substrate is s synthetic paper such as biaxially oriented polystyrene and the surface coating material is a flat black printing media such as iron-oxide pigmented latex metho-acrylic.

4. The light efficient display device of claim 1 wherein the device is primarily a rear lighted device comprising;

(a) a holder for the display device,

(b) a light source which is positionally fixed relative to the rear surface of the display device,

(c) a protective means for the purpose of shielding the device from elements in its environment and for preventing the undesired escape of light into areas surrounding the display device.

5. The light efficient display device of claim 1 wherein the device is primarily a front lighted device comprising;

(a) a holder for the display device,

(b) a light source which is positionally fixed relative to the front surface of the display device, and

(c) a protective means for the purpose of shielding the device from elements in its environment and for preventing the undesired escape of light into the areas surrounding the display device.

2. (d) whereby there is a contrast between the indicia and the uncoated portion of the substrate and said contrast remains constant whether the light is incident upon the front surface or is incident upon the rear surface if the incident light is constant in both cases.