Obviousness

Obviousness Analysis of US Patent 7384177 under 35 U.S.C. § 103

This analysis will assess the obviousness of US Patent 7384177 by identifying combinations of prior art references that would render the claims obvious to a person having ordinary skill in the art (PHOSITA). The PHOSITA in this field would likely have a background in optical engineering, display technology, or lighting design, with an understanding of light guiding principles, light source integration, and light extraction techniques.

Prior Art References from US7384177:

The patent explicitly incorporates by reference the entire disclosures of U.S. Pat. Nos. 4,897,771 and 5,005,108 for details on light sources. These will be considered as primary prior art, along with the various light-emitting panel assemblies described within US7384177 itself as examples of known technology at the time of its priority date (June 27, 1995).

Independent Claim 1 Analysis:

Claim 1: A light emitting assembly comprising a tray having a back wall and continuous side walls that form a hollow cavity or recess completely surrounded by the side walls, at least one light source located, mounted or positioned in the cavity or recess, and at least one sheet, film or substrate overlying the assembly for controlling the light emitted from the assembly to fit a particular application, wherein the tray acts as at least one of a back, side edge, and end edge reflector and has one or more secondary flat, angled, faceted or curved reflective or refractive surfaces to redirect at least a portion of the light emitted by the light source in a predetermined manner within the cavity or recess.

Combination 1: US 4,897,771 in view of general knowledge of light guides and reflectors.

• US 4,897,771 (or US 5,005,108): These patents, incorporated by reference, describe various light sources. A PHOSITA would be familiar with integrating these light sources into lighting assemblies.
• Motivation for Combination: It is well-established in the field of lighting and display technology to use reflectors to enhance light output and direct light. Providing a tray with a back wall and side walls to form a cavity for a light source, where the tray inherently acts as a reflector, would be an obvious design choice to maximize light capture and efficiency. The concept of "secondary reflective or refractive surfaces" (flat, angled, faceted, or curved) within such a cavity to further redirect light is a common optical design principle for light control. For instance, shaping a reflective surface behind a light source to direct light into a desired path is a fundamental application of optics. Adding an overlying sheet, film, or substrate for light control (e.g., diffusion, filtering, or display) is also a standard practice in illumination and display applications to achieve desired aesthetic or functional effects. The application of such a sheet to "fit a particular application" would be readily apparent to a PHOSITA.

Therefore, the features of Claim 1, when considered in light of a known light source (such as those described in US 4,897,771 or US 5,005,108) combined with routine optical design principles for light reflection and redirection within an enclosure, and the common use of overlying films for light control, would be obvious to a PHOSITA.

Independent Claim 15 Analysis:

Claim 15: A light emitting assembly comprising a tray having a back wall and continuous side walls that form a hollow cavity or recess completely surrounded by the side walls, at least two light sources located, mounted or positioned in the cavity or recess, and at least one sheet, film or substrate overlying the assembly for controlling the light emitted from the assembly to fit a particular application, wherein the tray acts as at least one of a back, side edge and end edge reflector and has at least one secondary flat, angled, faceted or curved reflective or refractive surface to facilitate better mixing of light rays within the cavity or recess to produce a desired light output color or uniformity.

Combination 2: US 4,897,771 (or US 5,005,108) in view of the use of multiple colored LEDs for color mixing, and general knowledge of optical mixing techniques.

• US 4,897,771 (or US 5,005,108): These patents disclose various light sources, including LEDs. The specification of US7384177 itself explicitly states that "a plurality of colored lights such as LEDs of different colors (red, blue, green) or a single LED with multiple colored chips may be employed to create white light or any other colored light output distribution by varying the intensities of each individual colored light." This indicates that the concept of using multiple colored LEDs to achieve desired light output (including white light) was known prior to the priority date of US7384177.
• Motivation for Combination: Given the known use of multiple colored LEDs (e.g., red, green, blue) to produce various colors or white light, a PHOSITA would be motivated to integrate these multiple light sources into a tray-based assembly for efficient light management. The challenge with multiple light sources, especially for color mixing or uniformity, is ensuring proper light integration before emission. Therefore, providing "secondary flat, angled, faceted or curved reflective or refractive surfaces to facilitate better mixing of light rays within the cavity or recess to produce a desired light output color or uniformity" would be an obvious design solution. Optical elements specifically designed for light mixing are standard in the art, and applying them within the reflective confines of a tray to improve the output quality from multiple light sources would be a predictable modification. The overlying sheet, film, or substrate would then serve to further control the mixed light, as in Claim 1.

Therefore, the features of Claim 15, which build upon the structure of Claim 1 by incorporating at least two light sources and emphasizing light mixing, would be obvious. The use of multiple colored LEDs for color mixing was a recognized technique, and optimizing their output through reflective and refractive surfaces within a contained assembly for improved color or uniformity is a straightforward engineering task for a PHOSITA.