1. A plasma display device expressing a video with gradations by selecting each of a plurality of subfields forming one field, each of the subfields having a weighted number of sustain pulses, comprising:
a sustain pulse number calculation unit calculating a display load factor of an input video signal and calculating a total number of sustain pulses of one field according to the display load factor; and
a gradation number selection unit selecting a gradation number being a sum of weights of all of the subfields according to the calculated total number of sustain pulses.
2. The plasma display device according to claim 1, further comprising:
a gradation number conversion unit performing gradation number conversion by dividing a dynamic range of the input video signal by the selected gradation number into equal steps.
3. The plasma display device according to claim 2, further comprising:
an error diffusion processing unit performing error diffusion processing when the gradation value after the gradation number conversion has a decimal fraction part.
4. The plasma display device according to claim 1, wherein said sustain pulse number calculation unit calculates the display load factor using a minimum gradation number of a plurality of selectable gradation numbers.
5. The plasma display device according to claim 1, wherein the plurality of gradation numbers selectable by said gradation number selection unit are the same in the number of subfields and different in weighting of each of the subfields.
6. The plasma display device according to claim 5, wherein in the plurality of gradation numbers selectable by said gradation number selection unit, a subfield with a smallest weight of each of the gradation numbers is the same in weight as subfields with smallest weights of the other gradation numbers, and a subfield with a largest weight of each of the gradation numbers is different in weight from subfields with largest weights of the other gradation numbers.
7. The plasma display device according to claim 1, wherein in the plurality of gradation numbers selectable by said gradation number selection unit, all of selection patterns of subfields for expressing gradation values of the minimum gradation number are included in selection patterns of subfields for expressing gradation values of the other gradation numbers.
8. The plasma display device according to claim 7, wherein the selection patterns of the subfields for expressing the gradation values of the other gradation numbers are formed by inserting selection patterns of other subfields between a gradation value where a specific subfield is first selected and a preceding gradation value when the gradation values of the minimum gradation number are arranged in an ascending order.
9. The plasma display device according to claim 2, further comprising:
an error diffusion processing unit performing error diffusion processing by replacing a specific gradation value with another gradation value to prevent use of the specific gradation value in the gradation values after the gradation number conversion.
10. The plasma display device according to claim 9, wherein the specific gradation value includes a gradation value where a specific subfield is first selected when the gradation values are arranged in an ascending order.
11. The plasma display device according to claim 9, wherein there are a larger number of the specific gradation values on the higher gradation value side, and there are no or a smaller number of the specific gradation values on the lower gradation value side.
12. The plasma display device according to claim 1, wherein said sustain pulse number calculation unit calculates the display load factor of one field and calculates the total number of sustain pulses of the one field according to the display load factor of the one field.
13. The plasma display device according to claim 12, wherein said sustain pulse number calculation unit calculates to decrease the total number of sustain pulses of the one field when the display load factor of the one field is-large.
14. The plasma display device according to claim 1, wherein said sustain pulse number calculation unit calculates the display load factor of each subfield and calculates the total number of sustain pulses of one field according to the display load factor of each subfield.
15. The plasma display device according to claim 1, wherein when a gradation number being a value obtained by dividing the calculated total number of sustain pulses by a number of gradation steps lies between a plurality of selectable gradation numbers, said gradation number selection unit selects either of preceding and subsequent selectable gradation numbers to the gradation number being the dividing value.
16. The plasma display device according to claim 15, wherein said gradation number selection unit selects, from among the preceding and subsequent selectable gradation numbers, the gradation number having the number of sustain pulses of a subfield with a small weight closer to the number of sustain pulses of a subfield with a smaller weight of the gradation number selected at the preceding time.
17. The plasma display device according to claim 1, further comprising:
a signal generation unit generating a sustain pulse signal for display by correcting the calculated total number of sustain pulses as necessary and dividing the total number of sustain pulses to correspond to a weight ratio among the subfields of the selected gradation number.
18. The plasma display device according to claim 17, wherein said signal generation unit performs correction to reduce the total number of sustain pulses so as to keep heat at a fixed temperature or lower or to reduce power by external operation.
19. The plasma display device according to claim 18, wherein said gradation number selection unit selects a minimum gradation number according to a correction result of said signal generation unit.
20. A control method of a plasma display device expressing a video with gradations by selecting each of a plurality of subfields forming one field, each of the subfields having a weighted number of sustain pulses, comprising:
a sustain pulse number calculation step of calculating a display load factor of an input video signal and calculating a total number of sustain pulses of one field according to the display load factor; and
a gradation number selection step of selecting a gradation number being a sum of weights of all of the subfields according to the calculated total number of sustain pulses.
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 vehicle navigation system, comprising:
a receiver for receiving remotely generated signals containing route instruction information;
a storage device for storing map information including first and second repeat destination locations between which a user of the vehicle navigation system repeatedly travels;
a display device for displaying map information and route instruction information; and
a controller in communication with said receiver, storage device, and display device, and being configured to:
provide at least one selection option to the user to select the first or second repeat destination location to which navigation information is to be provided;
in response to a selection by the user of a selection option indicative of the first or second repeat destination location being selected as a current destination location, request route instruction information from a remote location based on traffic information between a current location and the selected repeat destination location;
retrieve at least a portion of the map information stored in said storage unit;
receive from said receiver the requested route instruction information between the current location and selected repeat destination location; and
display on said display device the route instruction information on the retrieved map information to provide route instructions to the user.
2. The vehicle navigation system according to claim 1, further comprising a computing device at a call center configured to generate the route instruction information to communicate via the signals.
3. The vehicle navigation system according to claim 1, wherein said controller is further configured to:
receive the first repeat destination location from the user;
receive the second repeat destination location from the user;
request the map information including the first and second frequent destination locations from a remote location; and
maintain the map information in said memory device until either the first or second repeat destination location is changed by the user.
4. The vehicle navigation system according to claim 3, further comprising a position detection unit, wherein said controller is further configured to:
receive a notification from the user that the vehicle navigation system is positioned at the first repeat destination location;
request the current location from said position detection unit; and
store the current location received from said position detection unit in said storage device.
5. The vehicle navigation system according to claim 4, further comprising a position detection unit, wherein said controller is further configured to:
receive a notification from the user that the vehicle navigation system is positioned at the second repeat destination location;
request the current location from said position detection unit; and
store the current location received from said position detection unit in said storage device.
6. The vehicle navigation system according to claim 5, wherein said controller is further configured to request the map information after both the first and second repeat destination locations are stored.
7. The vehicle navigation system according to claim 1, wherein the at least one selection option is a soft-button displayed on said display device.
8. The vehicle navigation system according to claim 1, wherein the current destination location is the same as the unselected first or second repeat destination location.
9. The vehicle navigation system according to claim 1, wherein the route instruction information includes traffic information and said controller is further configured to display the traffic information on the retrieved map information.
10. The vehicle navigation system according to claim 1, wherein said controller stores in said memory device route instruction information associated with no traffic problems as a primary maneuver.
11. The vehicle navigation system according to claim 10, wherein said controller stores in said memory device route instruction information associated with different traffic problems as different secondary maneuvers.
12. The vehicle navigation system according to claim 11, wherein the route instruction information includes an instruction to cause said controller to select the primary or particular secondary maneuver based on the traffic information.
13. A method for providing vehicle navigation, comprising:
receiving remotely generated signals containing route instruction information;
storing map information including first and second repeat destination locations between which a user of the vehicle navigation system repeatedly travels; and
providing at least one selection option to the user to select the first or second repeat destination location to which navigation information is to be provided;
in response to a selection by the user of a selection option indicative of the first or second repeat destination location being selected as a current destination location, requesting route instruction information from a remote location based on traffic information between a current location and the selected repeat destination location;
retrieving at least a portion of the stored map information;
receiving the requested route instruction information between the current location and selected repeat destination location; and
displaying the route instruction information on the retrieved map information to provide route instructions for vehicle navigation to the user.
14. The method according to claim 13, further comprising generating the route instruction information to communicate via the signals.
15. The method according to claim 13, further comprising:
receiving the first repeat destination location from the user;
receiving the second repeat destination location from the user;
requesting the map information including the first and second frequent destination locations from a remote location; and
maintaining the map information in said memory device until either the first or second repeat destination location is changed by the user.
16. The method according to claim 15, further comprising:
receiving a notification from the user of being positioned at the first repeat destination location;
determining the current location; and
storing the current location.
17. The method according to claim 16, further comprising:
receiving a notification from the user of being positioned at the second repeat destination location;
determining the current position; and
storing the current location.
18. The method according to claim 17, further comprising requesting the map information after both the first and second repeat destination locations are stored.
19. The method according to claim 13, wherein said providing the at least one selection option includes displaying a soft-button.
20. The method according to claim 13, wherein the current destination location is the same as the unselected first or second repeat destination location.
21. The method according to claim 13, wherein the route instruction information includes traffic information, said displaying further including displaying the traffic information on the retrieved map information.
22. The method according to claim 13, further comprising storing route instruction information associated with no traffic problems as a primary maneuver.
23. The method according to claim 22, further comprising storing route instruction information associated with different traffic problems as different secondary maneuvers.
24. The method according to claim 23, further comprising selecting the primary or particular secondary maneuver based on the traffic information.