1. An image forming system comprising:
a first image forming apparatus capable of forming an image on a first side of a sheet and discharging the sheet having the image on the first side thereof, for double-sided printing by a tandem-outputting; and
a second image forming apparatus disposed in series at a downstream side of the first image forming apparatus in a sheet transporting direction, the second image forming apparatus being capable of receiving the sheet discharged from the first image forming apparatus which has the first image formed on the first side thereof, and forming a second image on a second side of the received sheet, for the double-sided printing by the tandem-outputting,
wherein the first image forming apparatus includes:
a first image forming section which performs image formation on the sheet;
a first fixing section which performs image fixation on the sheet on which the first image forming section performs the image formation; and
a first control section which is configured to control the first fixing section to set a tandem-outputting target fixing temperature for the double-sided printing to be lower than a first fiducial temperature serving as a non-tandem-outputting target fixing temperature at which the first image forming apparatus performs the image formation and the image fixation alone.
2. The image forming system according to claim 1, wherein the first control section controls the first fixing section to set the tandem-outputting target fixing temperature to be different in accordance with a type of the sheet.
3. The image forming system according to claim 1, wherein the first control section controls the first fixing section to set, for a first sheet of a job, the tandem-outputting target fixing temperature to be equal to the first fiducial temperature.
4. The image forming system according to claim 1, wherein the second image forming apparatus includes a temperature detection section which detects a temperature inside of the second image forming apparatus, and when the detected temperature inside of the second image forming apparatus is a predetermined temperature or more, the first control section controls the first fixing section to set the tandem-outputting target fixing temperature to be lower than the tandem-outputting target fixing temperature which is set when the detected temperature inside of the second image forming apparatus is less than the predetermined temperature.
5. The image forming system according to claim 4, wherein the first control section controls the first fixing section to set three or more different temperatures as the tandem-outputting target fixing temperature, and to set the tandem-outputting target fixing temperature to be lower as the temperature inside of the second image forming apparatus detected by the temperature detection section becomes higher.
6. The image forming system according to claim 1, wherein the first control section measures a printing duration during which the tandem outputting continues, and when the measured printing duration is a predetermined duration or more, the first control section controls the first fixing section to set the tandem-outputting target fixing temperature to be lower than the tandem-outputting target fixing temperature which is set when the printing duration is less than the predetermined duration.
7. The image forming system according to claim 1, wherein the first control section counts a number of sheets on which the tandem outputting is continuously performed, and when the counted number of sheets is a predetermined number or more, the first control section controls the first fixing section to set the tandem-outputting target fixing temperature to be lower than the tandem-outputting target fixing temperature which is set when the counted number of sheets is less than the predetermined number.
8. The image forming system according to claim 1, wherein the second image forming apparatus includes:
a second image forming section which performs the image formation on a sheet;
a second fixing section which performs the image fixation on the sheet on which the second image forming section performs the image formation; and
a second control section, configured to control the second fixing section to set a second tandem-outputting target fixing temperature to be lower than a second fiducial temperature serving as a non-tandem-outputting target fixing temperature at which the second image forming apparatus performs the image formation and the image fixation alone.
9. The image forming system according to claim 8, wherein the second control section controls the second fixing section to set the second tandem-outputting target fixing temperature to be different temperatures in accordance with a type of the sheet.
10. An image forming system comprising:
a first image forming apparatus capable of forming and fixing an image on a first side of a sheet, and thereafter discharging the sheet having the image formed on the first side thereof, for double-sided printing by a tandem-outputting; and
a second image forming apparatus disposed in series at a downstream side of the first image forming apparatus in a sheet transporting direction and capable of receiving the sheet having the first image formed on the first side thereof which is discharged from the first image forming apparatus and forming a second image on a second side of the received sheet, for the double-sided printing by the tandem-outputting; and
a control section configured to set a tandem-outputting target fixing temperature in the first image forming apparatus for the double-sided printing to be lower than a fiducial temperature serving as a non-tandem-outputting target fixing temperature in the first image forming apparatus at which the first image forming apparatus performs an image formation and an image fixation alone.
11. The image forming system according to claim 10, wherein the control section sets the tandem-outputting target fixing temperature to be different in accordance with a type of the sheet.
12. The image forming system according to claim 10, wherein the control section sets the tandem-outputting target fixing temperature in the first image forming apparatus to be equal to the fiducial temperature for the image fixation on a first sheet of a job.
13. The image forming system as claimed in claim 10, wherein the second image forming apparatus includes a temperature detection section which detects a temperature inside of the second image forming apparatus, and when the detected temperature inside of the second image forming apparatus is a predetermined temperature or more, the control section sets the tandem-outputting target fixing temperature in the first image forming apparatus to be lower than the tandem-outputting target fixing temperature which is set when the detected temperature inside of the second image forming apparatus is less than the predetermined temperature.
14. The image forming system as claimed in claim 13, wherein the control section is capable of setting three or more different temperatures as the tandem-outputting target fixing temperature in the first image forming apparatus, and the control section sets the tandem-outputting target fixing temperature lower as the temperature inside of the second image forming apparatus detected by the temperature detection section becomes higher.
15. The image forming system as claimed in claim 10, wherein the control section measures a printing duration during which the tandem outputting continues, and when the measured printing duration is a predetermined duration or more, the control section sets the tandem-outputting target fixing temperature in the first fixing section to be lower than the tandem-outputting target fixing temperature which is set when the printing duration is less than the predetermined duration.
16. The image forming system as claimed in claim 10, wherein the control section counts a number of sheets on which the tandem outputting is continuously performed, and when the counted number of sheets is a predetermined number or more, the control section sets the tandem-outputting target fixing temperature in the first image forming apparatus to be lower than the tandem-outputting target fixing temperature which is set when the counted number of sheets is less than the predetermined number.
17. The image forming system as claimed in claim 10, wherein the control section sets a second tandem-outputting target fixing temperature in the second image forming apparatus to be lower than a second fiducial temperature serving as a non-tandem-outputting target fixing temperature in the second image forming apparatus at which the second image forming apparatus performs the image formation and the image fixation alone.
18. The image forming system as claimed in claim 17, wherein the control section sets the second tandem-outputting target fixing temperature to be different temperatures in accordance with a type of the sheet.
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 for acquiring a satellite signal in a satellite receiver, the method comprising:
sampling data received by the satellite receiver during a plurality of sampling periods;
performing coherent integration to accumulate the sampled data over each of the plurality of sampling periods;
performing non-coherent integration based on the accumulated sampled data from the coherent integration, thereby providing a correlation output, wherein the non-coherent integration is performed for a plurality of iterations, including one or more intermediate iterations;
determining a peak-to-average power ratio (PAPR) based on the correlation output at a first one of the one or more intermediate iterations; and
determining whether to continue sampling data received by the satellite receiver by comparing the PAPR to a first predetermined threshold.
2. The method of claim 1, further comprising:
determining to continue sampling data received by the satellite receiver when the PAPR meets the first predetermined threshold.
3. The method of claim 2, further comprising:
determining to continue sampling data received by the satellite receiver when the PAPR does not exceed a second predetermined threshold.
4. The method of claim 2, further comprising:
terminating sampling data received by the satellite receiver when the PAPR exceeds both the first predetermined threshold and a second predetermined threshold.
5. The method of claim 1, further comprising:
terminating sampling data received by the satellite receiver when the PAPR does not meet the first predetermined threshold.
6. The method of claim 1, wherein the first predetermined threshold is set to provide a false alarm rate and a detection rate for correctly detecting the satellite signal.
7. The method of claim 1, further comprising:
determining a second PAPR based on the correlation output at a second one of the one or more intermediate iterations; and
determining whether to continue sampling data received by the satellite receiver by comparing the second PAPR to a second predetermined threshold.
8. The method of claim 1, wherein the satellite receiver accepts a GPS and a GLONASS satellite signal.
9. An apparatus for acquiring a satellite signal, comprising:
a plurality of integration units, each integration unit associated with a search space having a plurality of cells, each cell associated with a Doppler frequency bin and a code phase bin, each integration unit receiving a known code phase to search for in each cell, each integration unit having:
a coherent integration unit configured to accumulate sampled data received from the satellite signal, during a plurality of sampling periods; and
a non-coherent integration unit, coupled to the coherent integration unit, configured to perform non-coherent integration on the accumulated sampled data from the coherent integration unit for a predetermined number of iterations;
wherein each integration unit is configured to compare a peak-to-average power ratio at one or more intermediate iterations of the predetermined number of iterations to at least one threshold.
10. The apparatus of claim 9, wherein each integration unit operates concurrently within a particular Doppler frequency bin in the search space.
11. The apparatus of claim 9, wherein each integration unit is further configured to terminate performing non-coherent integration before the predetermined number of iterations have been made when the peak-to-average power ratio does not exceed a first predetermined threshold at an intermediate iteration of the one or more intermediate iterations.
12. The apparatus of claim 11, wherein each integration unit is further configured to terminate performing non-coherent integration before the predetermined number of iterations have been made when the peak-to-average power ratio exceeds a second predetermined threshold at an intermediate iteration of the one or more intermediate iterations.
13. The apparatus of claim 9, wherein each integration unit is further configured to compare the peak-to-average power ratio after completion of the predetermined number of iterations to a final predetermined threshold in order to determine an outcome in the search of a cell.
14. The apparatus of claim 9, wherein each integration unit is configured to search for a GPS satellite signal in a first configuration and a GLONASS satellite signal in a second configuration.
15. A method for acquiring a satellite signal, the method comprising:
receiving data from the satellite signal, the data associated with a code phase bin and Doppler frequency bin;
correlating the received data with a known code phase for a number of iterations, thereby providing correlated results;
performing coherent integration based on the correlated results over a plurality of sampling periods;
performing non-coherent integration based on results of the coherent integration, thereby providing a correlation output, wherein the non-coherent integration is scheduled to be performed for a plurality of iterations, including one or more intermediate iterations;
determining at a first one of the one or more intermediate iterations, whether the correlation output is not likely to match the received data to the known code phase; and
terminating at the first one of the one or more intermediate iterations, the correlation of the received data with the known code phase.
16. A method for acquiring a satellite signal, the method comprising:
receiving data from the satellite signal, the data associated with a code phase bin and Doppler frequency bin;
correlating the received data with a known code phase for a number of iterations, thereby providing correlated results;
performing coherent integration based on the correlated results over a plurality of sampling periods;
performing non-coherent integration based on results of the coherent integration, thereby providing a correlation output, wherein the non-coherent integration is scheduled to be performed for a plurality of iterations, including one or more intermediate iterations;
determining at a first one of the one or more intermediate iterations, whether the correlation output is not likely to match the received data to the known code phase;
determining at a second one of the one or more intermediate iterations, before the scheduled plurality of iterations has been completed, whether the correlation output is likely to indicate a match of the received data to the known code phase; and
terminating at the second one of the one or more intermediate iterations, the correlation of the received data with the known code phase.