See-through one-way light-emitting light guide
View Patent ↗A display system combines the principles of total internal reflection and halftone reflection. The display system includes a light guide, a light-reflecting see-through image disposed on the surface of the light guide, and a light-blocking see-through layer disposed over the image. A person viewing the light-blocking layer at a certain distance can see through the light guide without seeing the image. The display system can include a pair of eyeglasses that can provide self-illumination for night reading or serve as a hands-free flashlight. Also, novelty glasses can emit different colored lights as well as colored, lighted images. The display system can also include one-way see-through windows that emit lighted text and images for signage and advertising.
1. A display system mountable to a planar sheet of transparent material having a front surface and a back surface, the transparent material having a critical angle of incidence at the front surface and the back surface sufficient to establish total internal reflection within the transparent material, the display system comprising:
a light source mountable to the transparent material for injecting light into the transparent material at an angle of incidence at the front surface and the back surface that is greater than the critical angle of incidence to promote total internal reflection of the injected light within the transparent material; and
a film having a front layer and a back layer, the front layer being mountable to the back surface of the transparent material, wherein the mounted film alters the critical angle of incidence to be greater than the angle of incidence of the injected light so as to extract injected light into the film from the transparent material, the front layer comprising a one-way see-through image pattern illuminable by the extracted light and the back layer comprises a light-blocking see-through pattern.
2. The display system of claim 1 further comprising a transparent adhesive for mounting the film to the transparent material.
3. The display system of claim 1 wherein the one-way see-through image pattern is registered with the light-blocking see-through pattern.
4. The display system of claim 1 wherein the film includes a colorant to provide a color illuminated image pattern.
5. The display system of claim 4 wherein the colorant is disposed between the one-way see-through image pattern and the light-blocking see-through pattern.
6. The display system of claim 1 wherein the light source is disposed to edge illuminate the transparent material.
7. A method of making a display system in communication with a planar sheet of transparent material having a front surface and a back surface, the transparent material having a critical angle of incidence at the front surface and the back surface sufficient to establish total internal reflection within the transparent material, the method comprising:
mounting a light source to the transparent material for injecting light into the transparent material at an angle of incidence at the front surface and the back surface that is greater than the critical angle of incidence to promote total internal reflection of the injected light within the transparent material;
fabricating a film having a front layer and a back layer, the front layer comprising a one-way see-through image pattern and the back layer comprises a light-blocking see-through pattern; and
mounting the front layer of the film to the back surface of the transparent material, wherein the mounted film alters the critical angle of incidence to be greater than the angle of incidence of the injected light so as to extract injected light into the film from the transparent material to illuminate the image pattern.
8. The method of claim 7 wherein mounting the film to the transparent material comprises applying a transparent adhesive.
9. The method of claim 7 wherein fabricating the film comprises registering the one-way see-through image pattern with the light-blocking see-through pattern.
10. The method of claim 7 wherein fabricating the film comprises disposing a colorant to provide a color illuminated image pattern.
11. The method of claim 10 wherein the colorant is disposed between the one-way see-through image pattern and the light-blocking see-through pattern.
12. The method of claim 7 wherein the light source is disposed to edge illuminate the transparent material.
13. A display system mountable to a planar sheet of transparent material having a front surface and a back surface, the transparent material having a critical angle of incidence at the front surface and the back surface sufficient to establish total internal reflection within the transparent material, the display system comprising:
a light source mountable to the transparent material for injecting light into the transparent material at an angle of incidence at the front surface and the back surface that is greater than the critical angle of incidence to promote total internal reflection of the injected light within the transparent material; and
a film having a front layer and a back layer, the front layer being mountable to the back surface of the transparent material, wherein the mounted film alters the critical angle of incidence to be greater than the angle of incidence of the injected light so as to extract injected light into the film from the transparent material, the front layer comprising a one- way see-through image pattern illuminable by the extracted light and the back layer comprises a light-blocking see-through pattern, wherein the one-way see-through image pattern is registered with the light-blocking see-through pattern.
14. The display system of claim 13 further comprising a transparent adhesive for mounting the film to the transparent material.
15. The display system of claim 13 wherein the film includes a colorant to provide a color illuminated image pattern.
16. The display system of claim 15 wherein the colorant is disposed between the one-way see-through image pattern and the light-blocking see-through pattern.
17. The display system of claim 13 wherein the light source is disposed to edge illuminate the transparent material.