1. A liquid crystal display unit comprising:
a liquid crystal layer sandwiched between first and second substrates,
the first substrate including a reflector for reflecting incident light guided through the second substrate and the liquid crystal layer,
the reflector having a plurality of protuberances and recesses in each pixel region,
the distances between the respective peaks of each two adjacent protuberances in the pixel region being distributed in the range from 5 \u03bcm to 15 \u03bcm, with the incidence of peak distances within the range of \xb10.5 \u03bcm from the most frequent peak distance ranging from 40% to 80%,
the area of regular reflection surfaces of the reflector tilted at angles of 4.5\xb0 or less to the principal surface of the first substrate in the pixel region accounting for 35% or less of the area of the pixel region.
2. A liquid crystal display unit according to claim 1, wherein said reflector includes a plurality of pixel electrodes formed of a reflective metallic material.
3. A liquid crystal display unit according to claim 1, wherein said first substrate has an insulating film as the ground of the reflector.
4. A liquid crystal display unit according to claim 3, wherein said insulating film includes an organic insulating film.
5. A liquid crystal display unit according to claim 4, wherein said organic insulating film is formed of a photosensitive resin.
6. A liquid crystal display unit according to claim 1, wherein said first substrate has a reflective region having a reflector scattering incident light guided through the second substrate and the liquid crystal layer and a light transmitting region transmitting incident light guided through the first substrate.
7. A liquid crystal display unit according to claim 1, wherein the average height from the bottom of the each recess to the peak of each protuberance thereof is 1.2 \u03bcm or less.
8. A liquid crystal display unit according to claim 7, wherein said average height of protuberances and recesses is 0.1 \u03bcm or more.
9. A liquid crystal display unit according to claim 1, wherein the peak distances between the protuberances in the peak distance distribution range from 7.5 \u03bcm to 12.5 \u03bcm.
10. A liquid crystal display unit comprising:
a liquid crystal layer sandwiched between first and second substrates,
the first substrate including a reflector for reflecting incident light guided through the second substrate and the liquid crystal layer,
the reflector having a plurality of protuberances and recesses in each pixel region,
the distances between the respective peaks of each two adjacent protuberances in the pixel region being distributed in the range from 5 \u03bcm to 15 \u03bcm, with the incidence of peak distances within the range of \xb10.5 \u03bcm from the most frequent peak distance ranging from 40% to 80%,
the average height from the bottom of the each recess to the peak of each protuberance thereof ranging from 0.1 \u03bcm to 1.2 \u03bcm.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of treating a viscose process stream comprising oxidizing a reduced sulfur compound in the viscose process stream to produce a treated alkali metal sulfate liquid stream.
2. The method of claim 1, wherein the alkali metal is sodium.
3. The method of claim 1, wherein the step of oxidizing is performed at a pressure above atmospheric pressure and at a temperature of at least about 130\xb0 C. until the treated alkali metal sulfate liquid stream has a pH of less than about 10.
4. The method of claim 1, wherein the reduced sulfur compound comprises at least one of carbon disulfide, alkali metal salts of sulfide, thiocarbonate, thiosulfate and sulfite.
5. The method of claim 1, further comprising a step of adding a spent caustic solution to the viscose process stream prior to oxidizing the reduced sulfur compound.
6. The method of claim 1, wherein the step of oxidizing comprises providing an oxidant selected from the group consisting of air, oxygen-enriched air, and essentially pure oxygen.
7. The method of claim 6, wherein the oxidant comprises air and wherein an oxygen content in the range 2% to 18% is maintained in an off-gas.
8. The method of claim 7, wherein the oxygen content ranges from about 5% to about 9%.
9. The method of claim 1, wherein the oxidizing step is performed at a temperature of about 130\xb0 C. to about 260\xb0 C.
10. The method of claim 9, wherein the temperature is about 200\xb0 C. to about 220\xb0 C.
11. The method of claim 1, wherein the oxidizing step is performed for at least about 15 minutes.
12. The method of claim 1, wherein the treated liquid stream has a pH of about 2 to about 10.
13. The method of claim 12, wherein the pH ranges from about 2 to about 7.
14. The method of claim 1, further comprising a step of recovering alkali metal sulfate from the treated liquid stream.
15. The method of claim 14, wherein the recovering step comprises crystallizing alkali metal sulfate.
16. The method of claim 15, further comprising a step of introducing at least a portion of the recovered, crystallized alkali metal sulfate into the viscose process.
17. The method of claim 1, wherein the oxidizing step comprises injecting steam into the viscose process stream comprising the reduced sulfur compound.
18. A method of treating reduced sulfur compounds in a viscose process stream comprising steps of;
forming an alkaline solution of sodium cellulose xanthate;
treating the sodium cellulose xanthate solution to produce a regenerated cellulose material and at least one stream comprising reduced sulfur compounds;
oxidizing in the liquid phase the at least one stream comprising reduced sulfur compounds with air while maintaining about 5% to about 9% oxygen concentration in the off-gas, at an elevated temperature in the range of about 200\xb0 C. to about 220\xb0 C. and superatmospheric pressure for a duration of at least about 15 minutes, to produce a treated liquid stream having a pH in the range of about 2 to about 7, the treated liquid stream comprising sodium sulfate;
crystallizing sodium sulfate from the treated liquid stream; and
introducing at least a portion of the crystallized sodium sulfate to the viscose process.
19. A system for treating a stream from a viscose process mother liquor comprising:
a reduced sulfur species outlet from the viscose process mother liquor;
an oxidant source fluidly connected to the reduced sulfur species outlet;
a reactor fluidly connected downstream of the oxidant source and the reduced sulfur species outlet, the reactor comprising a sodium sulfate stream outlet; and
a separator fluidly connected to the sodium sulfate stream outlet and having a liquid phase outlet and a gaseous phase outlet.
20. The system of claim 19, further comprising a spent caustic species outlet from the viscose process, the spent caustic species outlet fluidly connected upstream of the reactor.
21. The system of claim 19, wherein the reduced sulfur species outlet is fluidly connected to the liquid-phase outlet.
22. The system of claim 19, further comprising a steam source fluidly connected upstream of the reactor.
23. The system of claim 19, wherein an oxidant from the oxidant source comprises at least one oxidant selected from the group consisting of air, oxygen-enriched air, and oxygen.
24. The system of claim 19, wherein the reactor has an internal pressure above atmospheric pressure.
25. The system of claim 19, wherein the reactor has an operating temperature of at least about 130\xb0 C.
26. The system of claim 19, wherein a reduced sulfur species from the reduced sulfur species source comprises at least one species selected from the group consisting of carbon disulfide, hydrogen sulfide, sodium thiocarbonate, sodium thiosulfate, and sodium sulfite.
27. The system of claim 19, further comprising an sodium sulfate recovery system fluidly connected to the liquid-phase outlet.
28. The system of claim 27, further comprising a conduit fluidly connecting the sodium sulfate recovery system and the viscose process.
29. A method of wet oxidation of a viscose process mother liquor comprising:
retrieving the viscose process mother liquor comprising at least one reduced sulfur species selected from the group consisting of carbon disulfide, hydrogen sulfide, sodium thiocarbonate, sodium thiosulfate, and sodium sulfite; and
oxidizing at least a portion of the reduced sulfur species at a pressure and temperature sufficient to produce an alkali sulfate stream having a pH of less than about 10.
30. The method of claim 29, further comprising adding a viscose process spent caustic solution to the viscose process mother liquor prior to performing the oxidizing step.
31. The method of claim 30, wherein the temperature is between about 130\xb0 C. to about 260\xb0 C.
32. The method of claim 31, wherein the temperature is between about 200\xb0 C. to about 220\xb0 C.
33. The method of claim 32, further comprising injecting steam into the viscose process mother liquor.
34. The method of claim 32, further comprising crystallizing alkali sulfate species from the alkali sulfate stream.
35. The method of claim 34, further comprising introducing the alkali sulfate into a viscose process system.
36. The method of claim 35, wherein the pressure is above atmospheric pressure.
37. The method of claim 36, wherein the pH is less than about 5.
38. The method of claim 37, wherein the alkali sulfate stream comprises sodium sulfate.