Reflection-enhanced flat panel display

• US 4,803,402 A
• Filed: 04/14/1987
• Issued: 02/07/1989
• Est. Priority Date: 08/22/1984
• Status: Expired due to Fees

• Current Assignee: Siemens Rail Automation Ltd. (Siemens AG)
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Wisnieff, Robert E., Raber, Peter E.
• Primary Examiner(s): Moore, David K.
• Assistant Examiner(s): O SHEA, SANDRA L
• Application Number:
  US07/038,440
• Time in Patent Office: 665 Days
• Field of Search: 313/584, 313/586, 313/587, 313/112, 313/113, 313/514, 313/517, 313/509, 315/169.3, 315/169.4
• US Class Current: 313/509
• CPC Class Codes: G09F 13/22 electroluminescent electroluminescent light sources per se H05B33/00
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes
• CPC Class Codes: H01J 11/12 with main electrodes provided on both sides of the discharge space

Abstract

A flat display panel arrangement including crossed patterns of parallel electrode wires and a reflective layer for increasing panel luminous intensity.

Claims

1. A flat display panel for displaying a predetermined pattern of light in response to an alternating applied electric field comprising:

light means for producing light in response to the application of said alternating applied electric field;

a first plurality of parallel electrodes for establishing selected electric fields, said first plurality of electrodes being disposed on a rear side of said light means;

a second plurality of parallel electrodes for cooperating with said first plurality in the establishment of said selected electric fields, said second electrode plurality being disposed on a front side of said light means and being parallel to the plane of said first electrode plurality, said electrodes of said second plurality being generally orthogonal to said first plurality of parallel electrodes;

front and rear dielectric charge storage layers, disposed respectively between said first and second pluralities of parallel electrodes and said light means, whereby said applied electric field passes through said front and rear dielectric charge storage layers, said front charge storage layer being substantially transparent, characterized in that;

said rear dielectric charge storage layer includes at least one pair of rear dielectric sublayers of different index of refraction extending over said first plurality of parallel electrodes, each sublayer having an optical thickness of one-quarter wavelength of a predetermined optical wavelength in said visible spectrum, said optical thicknesses and indices of refraction being such that said pair of rear dielectric sublayers cooperate to provide increased reflectivity in said visible spectrum, whereby said at least one pair of rear dielectric sublayers is subjected to said applied alternating electric field and said near dielectric charge storage layer performs both the functions of isolating said first plurality of electrodes from one another and storing charge and of reflecting light from said light means through said front dielectric charge storage layer.

2. A flat display panel according to claim 1, further characterized in that said front dielectric charge storage layer also includes at least one pair of front dielectric sublayers of different index of refraction extending over said second plurality of parallel electrodes, each sublayer having an optical thickness of one-quarter wavelength of a predetermined optical wavelength in said visible spectrum, said optical thicknesses and indices of refraction being such that said pair of front dielectric sublayers cooperate to provide an antireflection coating having decreased reflectivity in said visible spectrum.

3. A flat display panel according to claim 1, further characterized in that said light means is a gas mixture for producing light from a plasma in response to said alternating applied electric field and further comprising transparent support means for confining said gas mixture and supporting said electrodes and charge storage layers.

4. A flat display panel according to claim 2, further characterized in that said light means is a gas mixture for producing light from a plasma in response to said alternating applied electric field and further comprising transparent support means for confining said gas mixture and supporting said electrodes and charge storage layers.

5. A flat display panel according to claim 1, further characterized in that said light means is an electroluminescent layer.

6. A flat display panel according to claim 2, further characterized in that said light means is an electroluminescent layer.

7. A gas plasma display panel for displaying a predetermined pattern of light in response to an alternating applied electric field comprising:

front and rear plate means for establishing a display surface, said front means being substantially transparent;

gas means of predetermined composition for producing light in a display region of the visible spectrum from a plasma, in response to the application of said electric field, said plate means being effective for containing said gas means in a bounded volume between inner surfaces of said front and rear plate means;

a first plurality of parallel electrodes for establishing selected electric fields, said first plurality of electrodes being disposed between said front plate means and said gas means;

a second plurality of parallel electrodes for cooperating with said first plurality in the establishment of said selected electric fields, said second electrode plurality being disposed between said rear plate means and said gas means and being parallel to the plane of said first electrode plurality, said electrodes of said second plurality being generally orthogonal to said first plurality of parallel electrodes;

front and rear dielectric charge storage layers, disposed respectively between said first and second pluralities of parallel electrodes and said gas means, whereby said applied electric field passes through said front and rear dielectric charge storage layers, said front charge storage layer being substantially transparent; and

at least one secondary emission layer electrochemically compatible with said gas means for emitting electrons, characterized in that;

said front dielectric charge storage layer is substantially transparent in a predetermined window region of the visible spectrum, said window region including at least said display region;

said front plate means is substantially transparent in said predetermined window region;

said rear dielectric charge storage layer includes at least one pair of inorganic rear dielectric sublayers of different index of refraction, each sublayer having an optical thickness of one-quarter wavelength of a predetermined optical wavelength in the visible spectrum, so that said at least one pair of rear dielectric sublayers cooperate to provide increased reflectivity in said display region of the visible spectrum and light produced within said bounded volume by said gas means and having a wavelength within said display region of the visible speotrum is reflected from said rear dielectric charge storage layer through said front dielectric charge storage layer and said front plate means to increase the amount of light passing therethrough, whereby said rear dielectric charge storage layer performs both the functions of reflecting display radiation and charge storage.

8. A gas plasma display panel according to claim 7, further characterized in that said secondary emission layer is one of said at least one pair of dielectric sublayers so that said secondary emission layer performs both the functions of electron emission and reflection enhancement.

9. A gas plasma display panel according to claim 7, further characterized in that said rear plate means and said rear dielectric charge storage layer, including said at least one pair of inorganic rear dielectric sublayers, are substantially transparent in a background region of the visible spectrum included in said window region, whereby an optical viewing path exists in said background region through said front and rear dielectric charge storage layers and said front and rear plate means and said rear dielectric charge storage layer performs the additional function of passing light in said background region through said display, as well as reflecting light in said display region.

10. A gas plasma display panel according to claim 7, further characterized in that said front dielectric charge storage layer includes at least one pair of front dielectric sublayers of different index of refraction, each sublayer having an optical thickness of one-quarter wavelength of a predetermined optical wavelength in the visible spectrum, whereby said at least one pair of front dielectric sublayers cooperate to provide decreased reflectivity in said display region of the visible spectrum, whereby transmission of light produced within said bounded volume by said gas means and having a wavelength within said display region of the visible spectrum is enhanced.

11. A gas plasma display panel according to claim 8, further characterized in that said rear plate means and said rear dielectric charge storage layer, including said at least one pair of inorganic rear dielectric sublayers, are substantially transparent in a background region of the visible spectrum included in said window region, whereby an optical viewing path exists in said background region through said front and rear dielectric charge storage layers and said front and rear plate means and said rear dielectric charge storage layer performs the additional function of passing light in said background region through said display panel, as well as reflectling light in said display region storing charge and emitting electrons.

12. A gas plasma display panel according to claim 8, further characterized in that said front dielectric charge storage layer includes at least one pair of front dielectric sublayers of different index of refraction, each sublayer having an optical thickness of one-quarter wavelength of a predetermined optical wavelength in the visible spectrum, whereby said at least one pair of front dielectric sublayers cooperate to provide decreased reflectivity in said display region of the visible spectrum, whereby transmission of light produced within said bounded volume by said gas means and having a wavelength within said display region of the visible spectrum is enhanced.

13. A gas plasma display panel according to claim 9, further characterized in that said front dielectric charge storage layer includes at least one pair of front dielectric sublayers of different index of refraction, each sublayer having an optical thickness of one-quarter wavelength of a predetermined optical wavelength in the visible spectrum, whereby said at least one pair of front dielectric sublayers cooperate to provide decreased reflectivity in said display region of the visible spectrum and are substantially transparent in said background region of the visible spectrum, whereby transmission of light produced within said bounded volume by said gas means and having a wavelength within said display region of the visible spectrum is enhanced.

14. A gas plasma display panel according to claim 9, further characterized in that said secondary emission layer is one of said at least one pair of dielectric sublayers so that said secondary emission layer performs both the functions of electron emission and reflection enhancement.