1. A color pixel element for field emission display, the color pixel element comprising:
a sealed container having a light permeable portion;
a cathode;
at least two anodes spaced from the light permeable portion;
at least two phosphor layers, wherein each one of the at least two phosphor layers is formed on an end surface of a corresponding anode and spaced from the light permeable portion; and
at least two CNT strings electrically connected to and contacting the cathode, wherein each one of the at least two CNT strings has an emission portion corresponding to one of the at least two phosphor layer; each one of the at least two CNT strings comprises a plurality of first CNT bundles and a plurality of second CNT bundles, the plurality of second CNT bundles are taller than and project over the plurality of first CNT bundles, and each of the plurality of second CNT bundles functions as an electron emitter;
wherein the cathode, the at least two anodes, the at least two phosphor layers, and the at least two CNT strings are enclosed in the sealed container.
2. The color pixel element for field emission display as claimed in claim 1, wherein the emission portion of each one of the at least two CNT strings is arranged between the light permeable portion and a corresponding phosphor layer of the at least two phosphor layers.
3. The color pixel element for field emission display as claimed in claim 1, wherein a diameter of each one of the at least two CNT string is in a range from about 1 micrometer to about 100 micrometers, and a length of each one of the at least two CNT strings is in a range from about 0.1 centimeters to about 10 centimeters.
4. The color pixel element for field emission display as claimed in claim 1, wherein the plurality of first CNT bundles and the plurality of second CNT bundles are closely packed, and each one of the plurality of first CNT bundles and the plurality of second CNT bundles comprises a plurality of CNTs substantially parallel to each other and joined by van der Waals attractive force.
5. The color pixel element for field emission display as claimed in claim 4, wherein the CNTs at the emission portion have a diameter less than 5 nanometers and a number of graphite layers in a range from about 2 to about 3.
6. The color pixel element for field emission display as claimed in claim 4, wherein the CNTs in a portion of the at least two CNT strings other than the emission portion have a diameter of about 15 nanometers and a number of graphite layers more than 5.
7. The color pixel element for field emission display as claimed in claim 1, further comprising at least two anode terminals and a cathode terminal, wherein each one of the at least two anode terminals is electrically connected to a corresponding anode, and the cathode terminal is electrically connected to the cathode.
8. The color pixel element for field emission display as claimed in claim 7, wherein the at least two anode terminals and the cathode terminal run from inside of the sealed container to outside of the sealed container.
9. The color pixel element for field emission display as claimed in claim 7, wherein the cathode, the at least two anodes, the cathode terminal and the at least two anode terminals are made of thermally and electrically conductive materials.
10. The color pixel element for field emission display as claimed in claim 9, wherein the at least two anodes are made of metal materials, and the end surfaces of the at least two anodes are polished metal surfaces or plated metal surfaces.
11. The color pixel element for field emission display as claimed in claim 1, wherein the sealed container is a hollow member that defines an inner space in vacuum.
12. The color pixel element for field emission display as claimed in claim 1, wherein the sealed container is a hollow cube; a side length of the sealed container is in a range from about 2 millimeters to about 10 millimeters.
13. The color pixel element for field emission display as claimed in claim 1, wherein the light permeable portion has a surface selected from the group consisting of a plane surface, a spherical surface, and an aspherical surface.
14. The color pixel element for field emission display as claimed in claim 1, wherein the at least two CNT strings are electrically connected to and contacting the cathode by conductive paste.
15. The color pixel element for field emission display as claimed in claim 1, wherein the emission portion of each one of the at least two CNT strings is suspended.
16. The color pixel element for field emission display as claimed in claim 1, wherein a distance between the emission portion of each one of the at least two CNT strings and the corresponding phosphor layer is less than 5 millimeters.
17. The color pixel element for field emission display as claimed in claim 1, wherein the emission portion of each one of the at least two CNT strings is arranged parallel to a surface of the corresponding phosphor layer and a surface of the light permeable portion.
18. The color pixel element for field emission display as claimed in claim 1, wherein distances between the cathode and each one of the at least two anodes are substantially equal, and distances among adjacent anodes are substantially equal.
19. A color pixel element for field emission display, the color pixel element comprising:
a sealed container having a light permeable portion;
a cathode;
at least two anodes;
at least two phosphor layers, wherein each one of the at least two phosphor layers is formed on an end surface of a corresponding anode and spaced from the light permeable portion; and
at least two cathode emitters electrically connected to and contacting the cathode, wherein each one of the at least two cathode emitters is parallel to a surface of the corresponding phosphor layer and a surface of the light permeable portion and has an emission portion located between a corresponding phosphor layer and the light permeable portion;
wherein the cathode, the at least two anodes, the at least two phosphor layers, and the at least two cathode emitters are enclosed in the sealed container.
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. An engine power management method for a hybrid electric vehicle powertrain having power delivery components comprising an engine, an electric generator, an electric motor, a battery electrically coupled to the generator and the motor, and gearing mechanically coupling the motor, the generator and the engine to define a power delivery system with multiple power flow paths as engine mechanical power and motor and generator power are distributed to vehicle traction wheels, the method comprising the steps of:
determining a pre-calibrated power delivery loss for the individual components for various vehicle speeds;
determining a pre-calibrated minimum value for the component power delivery loss value for the various vehicle speeds;
determining a pre-calibrated engine speed corresponding to the minimum power loss values for the various vehicle speeds;
entering the pre-calibrated engine speeds in a table; and
selecting from the table an engine speed corresponding to minimum total powertrain power losses whereby the powertrain operates with optimum total power delivery system efficiency for a given total power command.
2. The method sets forth in claim 1 including the step of determining a changed engine torque command during a transition period following a change in total power command;
computing an unfiltered engine torque command using the change in total power command and actual engine speed;
filtering the unfiltered engine torque command to effect a filter time lag to modify a rate of change of the engine torque command; and
increasing the engine torque command during the transition period whereby a quick response to a changed total power command is obtained.
3. The method set forth in claim 2 including the step of filtering an engine speed command following the change in total power command whereby a controlled rate of increase of the engine speed command is effected until a target engine speed is achieved corresponding to a changed total power command and a given vehicle speed.
4. The method set forth in claim 2 including the step of determining a changed engine torque command during the transition period following a change in total power command;
computing an unfiltered engine torque command using the change in total power command and actual engine speed;
filtering the unfiltered engine torque command to effect a filter time lag to modify a rate of change of the engine torque command; and
increasing the engine torque command during the transition period whereby a quick response to a changed total power command is obtained.
5. An engine power management method for a hybrid electric vehicle powertrain having separate power delivery components including at least an engine and an electric motor, the components defining power flow paths to vehicle traction wheels, the method comprising the steps of:
determining a pre-calibrated power delivery loss for the power delivery components for a given engine speed, the engine speed being stored in a data storing medium;
determining a minimum power delivery loss for a given engine speed and a total engine power command by adjusting an engine speed command;
adjusting an engine torque command to a value corresponding to the engine speed command, whereby, for a given vehicle speed and total power command, there is an engine speed such that a total powertrain power loss is a minimum.
6. The method set forth in claim 5 wherein the data storage medium is a read-only memory portion of an electronic vehicle system controller.
7. The method set forth in claim 5 wherein the data storage medium is configured to store in a look-up table a value of pre-calibrated engine speeds for each vehicle speed and for each total power command such that total powertrain power loss is of minimum value, whereby maximum powertrain efficiency is achieved.
8. The method set forth in claim 7 wherein the look-up table is pre-calibrated and developed off-line.
9. An engine power management method for a hybrid electric vehicle powertrain having separate components including at least two of a group comprising an engine, an electric motor, a generator, a battery and power transfer gearing, the components defining power flow paths to vehicle traction wheels, the method comprising the steps of:
determining an engine speed for a given vehicle speed and a given total power command to minimize total powertrain power losses; those losses being a function of total power command and vehicle speed;
total power command and vehicle speed, together with multiple values for engine speed, being inputs for calculating power losses for the components;
adding the component losses together to obtain total powertrain loss;
determining an engine speed corresponding to minimum total power loss and storing it as data in an electronic computer memory; and
accessing the data to obtain an engine speed corresponding to various total power commands and vehicle speeds that will achieve a minimum total power loss, whereby maximum total powertrain efficiency is achieved.
10. The method set forth in claim 9 wherein the step of accessing the data is followed by adjusting engine torque to a value corresponding to the stored engine speed.