1. An image forming apparatus comprising:
a scanner;
a hard disk drive in which a region at which data is stored is divided into a plurality of regions by partitions;
a pointer setting unit in which a first pointer for storing image data generated on the basis of an image read by the scanner at one region of said plurality of regions, and a plurality of second pointers which are provided so as to correspond to the regions other than the region in order to store data other than the image data at regions other than the region are set; and
a pointer replacing unit configured to replace the first pointer with one pointer of said plurality of second pointers in predetermined timings.
2. The image forming apparatus according to claim 1, further comprising;
a display unit;
a status display unit configured to display statuses of the regions of the hard disk drive for predetermined items on the display unit; and
a threshold value setting unit configured to set threshold values in accordance with the predetermined items, wherein
the predetermined timings are moments exceeding threshold values set in the threshold value setting unit.
3. The image forming apparatus according to claim 1, wherein
when data is stored in one of said plurality of second pointers which are replaced at the pointer replacing unit, the data is moved to a region at which the image data has been stored by the first pointer.
4. The image forming apparatus according to claim 3, wherein
the movement of the data is overwriting data.
5. The image forming apparatus according to claim 1, wherein
an image data storage impossible region at which the image data cannot be stored is provided to the regions other than the region, and
at the time of carrying out a replacement of pointers, the pointer replacing unit excepts a second pointer set in accordance with the image data storage impossible region from second pointers to be objects to be replaced.
6. The image forming apparatus according to claim 1, further comprising:
an index number storage unit which stores index numbers in accordance with said plurality of regions at which the data of the hard disk drive are stored; and
an index number increasing unit configured to increase an index number of the index number storage unit corresponding to a region at which the image data has been stored by the first pointer after the first pointer is replaced with one of said plurality of second pointers, wherein
the one of said plurality of second pointers which is replaced at the pointer replacing unit is selected from among pointers whose index numbers are the least.
7. The image forming apparatus according to claim 6, further comprising:
a display unit;
a status display unit configured to display statuses of the regions of the hard disk drive for predetermined items on the display unit; and
a threshold value setting unit configured to set threshold values in accordance with the predetermined items, wherein
the predetermined timings are moments exceeding threshold values set in the threshold value setting unit.
8. The image forming apparatus according to claim 6, wherein
an image data storage impossible region at which the image data cannot be stored is provided to the regions other than the region, and
at the time of carrying out a replacement of pointers, the pointer replacing unit excepts a second pointer set in accordance with the image data storage impossible region from second pointers to be objects to be replaced.
9. The image forming apparatus according to claim 1, further comprising
a timer to clock a time period, wherein
the predetermined timings are moments when a time period clocked by the timer has passed over a clock time set in advance.
10. A method for replacing a region at which image data of an image forming apparatus having a scanner and a hard disk drive is stored, comprising:
generating image data on the basis of an image read by the scanner;
storing the generated image data at one region of a plurality of regions in accordance with a first pointer for storing at the region provided in the hard disk drive by partitions; and
replacing the first pointer with one of a plurality of second pointers which are provided so as to correspond to the regions other than the region in order to store data at regions other than the region in predetermined timings.
11. The method according to claim 10, wherein
the predetermined timings are moments exceeding threshold values set in accordance with predetermined items of the statuses of the regions of the hard disk drive.
12. The method according to claim 10, further comprising
moving data to a region at which the image data has been stored by the first pointer when the data is stored in one of said plurality of second pointers to be replaced.
13. The method according to claim 10, further comprising
increasing an index number corresponding to the region at which the image data has been stored by the first pointer by 1 after the first pointer is replaced with one of said plurality of second pointers, wherein
the one of said plurality of second pointers is selected from among pointers whose index numbers are the least.
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 computing a running average of samples of data over a number of samples, the method comprising steps of:
receiving and accumulating data samples in plurality of sample-accumulators of a signal averaging circuit while counting the number of samples received in a sample counter;
alternately selecting an average of the samples accumulated in each of the plurality of sample accumulators by dividing the sum of the samples accumulated in each of the plurality of sample accumulators by the number of samples accumulated therein; and
alternately resetting each of the sample accumulators after a number (N) of samples have been received,
whereby a running average is provided over ((M\u2212)\xb7N) samples where M is the number of sample-accumulators.
2. A method according to claim 1, wherein the step of alternately selecting an average of the samples accumulated in each of the plurality of sample-accumulators comprises the steps of
dividing the sum of the samples accumulated in each of the plurality of sample-accumulators by the number of samples received in each of the plurality of sample-accumulator to provide from each of the plurality of sample-accumulators an average of the samples accumulated therein; and
interleaving selection of the average of the samples accumulated from each of the plurality of sample-accumulators.
3. A method according to claim 1, wherein the step of alternately selecting an average of the samples accumulated in each of the plurality of sample-accumulators comprises the steps of:
alternately selecting the sum of the samples accumulated in each of the plurality of sample-accumulators; and
dividing the sum of the samples accumulated in a selected sample-accumulator by the number of samples received to provide an average of the samples accumulated therein.
4. A method according to claim 3, further comprising the step of resetting the sample-counter following N of cycles.
5. A method according to claim 4, wherein the step of dividing the sum of the samples comprises the step of dividing the sum of the samples accumulated in a selected sample-accumulator by the sum of ((M\u22121)\xb7N ) and the number of samples received after the last sample counter reset where M is number of sample-accumulators.
6. A method according to claim 5, wherein the step of receiving and accumulating samples comprises the step of receiving and accumulating samples in a first and a second sample-accumulator.
7. A method according to claim 6, wherein the step of interleaving selection of the average and alternating reset of each of the sample-accumulators comprises the steps of:
after N samples have been received resetting the second sample-accumulator while resetting the sample counter after the reset selecting as the running average the average of the samples accumulated in the first sample-accumulator;
after 2N samples have been received resetting the first sample-accumulator while resetting the sample-counter after the reset selecting as the running average the average of the samples accumulated in the second sample-accumulator; and
repeating the above steps.
8. A method according to claim 1, further comprising an initial step of selecting the number (N) of samples over which the running average is to be provided.
9. A signal averaging circuit for computing a running average over a number of samples of data, the circuit comprising:
a plurality of sample-accumulators to receive and accumulate samples;
a sample-counter to count the number of samples received up to a predetermined number (N);
a selection circuit to alternately select a sum of the samples accumulated in each of the plurality of sample-accumulators;
a divider to divide the sum of the samples accumulated in the selected sample-accumulator by the sum of ((M\u22121)\xb7N) and the number of samples received after the last sample counter reset to provide from the selected sample-accumulator an average of the samples accumulated therein; and
a reset circuit to alternately reset each of the sample-accumulators after N samples have been received, whereby, a running average is provided over ((M\u22121)\xb7N) samples where M is number of sample accumulators.
10. A circuit according to claim 9, wherein the reset circuit is configured to reset the sample-counter following N of cycles.
11. A circuit according to claim 10, wherein the plurality of sample-accumulators comprises a first sample-accumulator and a second sample-accumulator.
12. A circuit according to claim 11, wherein the selection circuit is adapted to select the sum of the samples accumulated in the first sample-accumulator to compute the running average after N samples (and subsequent odd sets of N samples) have been received, and to select the sum of the samples accumulated in the second sample-accumulator to compute the running average after 2N samples (and subsequent even sets of N samples) have been received.
13. A circuit according to claim 12, wherein the reset circuit is adapted to reset the second sample-accumulator after N samples (and subsequent odd sets of N samples) have been received while the average of the samples accumulated in the first sample-accumulator is selected as the running average, and to reset the first sample-accumulator after 2N samples (and subsequent even sets of N samples) have been received while the average of the samples accumulated in the second sample-accumulator is selected as the running average.
14. A circuit according to claim 13, wherein the sample-counter is a n-bit forward counter where N=2n, and wherein the sample-counter is configured to roll over to zero after each set of N samples has been received.
15. A signal averaging circuit for computing a running average over a number of samples of data the circuit comprising:
a plurality of sample-accumulating means for receiving and accumulating digital samples of a signal;
counting means for counting the number of samples received in the plurality of sample-accumulating means;
selection means for alternately selecting from an output of each of the plurality of accumulating means a sum of the samples accumulated therein;
dividing means for dividing the sum of the samples accumulated in the selected sample-accumulating means by the number of samples received in the selected sample-accumulating means to provide average of the samples accumulated therein; and
reset means for alternately resetting the plurality of sample-accumulating means at regular intervals offset with respect to each other by N samples. whereby, a running average is provided.
16. A circuit according to claim 15, wherein the reset means is further adapted to reset the sample counter when it reaches N.
17. A circuit according to claim 16 wherein the plurality of sample-accumulating means comprises a first sample-accumulator and a second sample-accumulator.
18. A circuit according to claim 17, wherein the selection means is adapted to select the sum of the samples accumulated in the first sample-accumulator to compute the running average after N samples (and subsequent odd sets of N samples) have been received, and to select the sum of the samples accumulated in the second sample-accumulator to compute the running average after 2N samples (and subsequent even sets of N samples) have been received.
19. A circuit according to claim 18, wherein the reset means is adapted to reset the second sample-accumulator after N samples (and subsequent odd sets of N samples) have been received while the average of the samples accumulated in the first sample-accumulator is selected as the running average, and to reset the first sample-accumulator after 2N samples (and subsequent even sets of N samples) have been received while the average of the samples accumulated in the second sample-accumulator is selected as the running average.
20. A circuit according to claim 19, wherein the counting means is a n-bit forward counter where N=2n, and wherein the sample-counter is configured to roll over to zero after each set of N samples has been received.