Led-based lighting devices and systems based on light panels having transparent waveguides

A light panel for producing an illumination or a visual effect, comprising:

• a transparent front panel;
• a transparent back panel;
• a side frame which supports the transparent front panel and the transparent back panel;
• multiple light-emitting diodes (LEDs) attached to an inner surface of the side frame;
• a light guide positioned between the transparent front panel and the transparent back panel, wherein the light guide is configured to propagate light emitted by the multiple LEDs, and to direct a portion of the light out of the light panel in a direction toward the transparent front panel;
• and
• a transparent sheet positioned between the light guide and the transparent back panel, wherein the transparent sheet is patterned with a group of reflective elements for directing the portion of the light toward the transparent front panel, wherein the light panel is substantially transparent when the multiple LEDs are turned off.

A light window for producing an illumination or a visual effect, comprising:

• a regular window including a glass panel and a window frame;
• a light panel positioned behind the glass panel and between the window frame, the light panel including:
• a transparent front panel;
• a transparent back panel;
• a side frame which supports the transparent front panel and the transparent back panel;
• multiple light-emitting diodes (LEDs) attached to an inner surface of the side frame;
• and
• a light guide positioned between the transparent front panel and the transparent back panel, wherein the light guide is configured to propagate light emitted by the multiple LEDs, and direct a portion of the light out of the light panel in a direction toward the transparent front panel, wherein at least one surface of the light guide is configured with either a refractive structure or a reflective structure for directing the portion of the light toward the transparent front panel;
• and
• wherein the light panel is substantially transparent to a viewer when the multiple LEDs are turned off.

A light window for producing window light, comprising:

• a regular window including a glass panel and a window frame;
• a light panel positioned behind the glass panel and between the window frame, the light panel including:
• a transparent front panel;
• a transparent back panel;
• a side frame which supports the transparent front panel and the transparent back panel;
• multiple light-emitting diodes (LEDs) attached to an inner surface of the side frame;
• a light guide positioned between the transparent front panel and the transparent back panel, wherein the light guide is configured to propagate light emitted by the multiple LEDs, and direct a portion of the light out of the light panel in a direction toward the transparent front panel;
• and a transparent sheet positioned between the light guide and the transparent back panel, wherein the transparent sheet is patterned with a group of reflective elements for directing the portion of the light toward the transparent front panel, wherein the light panel is substantially transparent to a viewer when the multiple LEDs are turned off.

A light panel for producing an illumination or a visual effect, comprising:

• a light panel frame;
• two transparent panels spaced from each other and engaged to the light panel frame;
• light-emitting diodes (LEDs) engaged to the light frame and located to emit LED light into a space between the two transparent panels;
• and
• a transparent material positioned between the transparent panels and structured as a light guide to receive the LED light from the LEDs and to guide the received LED light within the transparent material while transmitting a portion of the received LED light out of the light guide towards one of the transparent panels to enable the light guide to appear as a bright opaque structure between the two transparent panels when the LEDs are turned on, and substantially transparent between the two transparent panels when the LEDs are turned off.