JP5456705B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus having a function of shifting its own apparatus to a power saving mode at a set time.

  In the image forming apparatus, when the use is stopped for a predetermined time or longer, the image forming apparatus shifts to the power saving mode. For example, as shown in FIG. 7, a job execution signal JobOn that is high only during job execution is input to the off-delay timer 10, and the job execution signal JobOn transitions to a low level as shown in FIG. 8B. Thereafter, the output of the off-delay timer 10 transitions to a low level after the time T1 has elapsed. The falling edge of this signal is detected by the rising edge detection circuit 11, and the device is shifted to the power saving mode using the pulse as the power saving shift trigger signal ST.

  In order to further shorten this time T1, a weekly timer 12 is provided as shown in FIG. 7, and a pulse is output from the output terminal SO at the time set for each day of the week. At the same time, it is input to the OR gate 13, and the output of the OR gate 13 is used as a power saving transition trigger signal ST.

  As a result, as shown in FIG. 8A, after the job execution signal JobOn transits to a low level, a pulse is output from the output terminal SO within a time shorter than the time T1, and this passes through the OR gate 13 to save power. It is output as the transition trigger signal ST and shifts to the power saving mode. In FIG. 7, an output terminal RO of the weekly timer 12 is for canceling the power saving mode at a set time for each day of the week and enabling the user to use the image forming apparatus immediately.

JP 2003-324556 A

  However, as shown in FIG. 8B, even if a pulse is output from the output terminal SO of the weekly timer 12 when the job execution signal JobOn is at a high level, the job execution is prioritized and this pulse is ignored. Therefore, the time from the stop of the job to the transition to the power saving mode is relatively long as time T1.

  In view of such problems, it is an object of the present invention to provide an image forming apparatus capable of further saving power.

In the first aspect of the present invention, there is provided power saving control means for shifting the own apparatus to a power saving mode based on activation of a power saving shift trigger signal activated at a set time and whether or not a job is being executed. In the image forming apparatus, the power saving control unit includes:
A time measuring means for measuring an elapsed time from the activation;
Time setting means for setting the time;
In response to the activation, the apparatus includes power saving transition control means for shifting the own apparatus to a power saving mode if the elapsed time is within the set time and the job is not being executed.

  According to the configuration of the first aspect, in response to the activation of the power saving transition trigger signal activated at the set time, the elapsed time from the activation is within the set time and the job is being executed. Otherwise, since the own apparatus is shifted to the power saving mode, it is possible to achieve further power saving.

  Other objects, characteristic configurations and effects of the present invention will become apparent from the following description read in connection with the appended claims and the drawings.

It is a figure which shows the power saving transition trigger signal generation circuit which concerns on Example 1 of this invention. It is a time chart which shows operation | movement of the circuit of FIG. 1 is a schematic block diagram illustrating an image forming system according to Embodiment 1 of the present invention. It is a schematic flowchart which shows the process by the program used instead of the circuit 50 of FIG. 1 based on Example 2 of this invention. 5 is a time chart showing operations related to the processing of FIG. 4. It is a schematic flowchart corresponding to the process of FIG. 4 based on Example 3 of this invention. It is a figure which shows the conventional power saving transition trigger signal generation circuit. It is a time chart which shows operation | movement of the circuit of FIG.

  FIG. 3 shows an image forming system to which the present invention is applied.

  In this system, an image forming apparatus 20 and a personal computer (PC) 30 are connected by a network 40.

  In the image forming apparatus 20, overall control is performed by the control unit 21. The control unit 21 includes a program storage unit and a CPU that executes the program. The real time clock (RTC) 22 outputs the current time t, and is backed up by a battery so that it can be operated even if a power failure occurs. The control unit 21 includes the power saving transition trigger signal generation circuit of FIG. 1, and the output current time t of the RTC 22 is supplied to the weekly timer 12, and the weekly timer 12 has the current time t set therein. When the power transition time comes, one pulse (primary power saving transition trigger signal) is output from the output terminal SO, and when the set power saving cancellation time comes, one pulse (power saving cancellation) (Trigger signal) is output. The control unit 21 also displays the current time t output from the RTC 22 on the operation panel 23.

  The control unit 21 overwrites the default or a changed setting value stored in the storage unit 24 with the information set on the operation panel 23, and reads the original image on the scanner 25 based on the current setting value. The image data is stored in the storage unit 24. The control unit 21 further causes the image processing unit 26 to perform processing such as rotation and reduction on the image data based on the set value and the orientation of the automatically selected paper, and causes the image forming unit 27 to print the image on the paper. Or the communication interface 28 is caused to transmit image data to the PC 30. The storage unit 24 includes a memory and a hard disk device.

  The power saving transition trigger signal generation circuit of FIG. 1 further includes a power saving mode transition retry circuit 50 between the output terminal SO of the weekly timer 12 and one input terminal of the OR gate 13 in addition to the circuit of FIG. It is.

  The power saving mode transition retry circuit 50 includes an N-shot multivibrator 51 to which a pulse from the output terminal SO is supplied, an AND gate 52 to which an output of the vibrator 51 is supplied to one input terminal, and the other of the AND gate 52. And an inverter 53 connected to the input terminal, and the output of the AND gate 52 is supplied to the reset input terminal R of the N-shot multivibrator 51.

  In response to the pulse from the output terminal SO, the N-shot multivibrator 51 outputs N pulses having a period T, and stops the pulse output if the pulse is supplied to the reset input terminal R during this period. The N-shot multivibrator 51 includes, for example, an astable multivibrator, a counter that counts the output pulses, and a coincidence detection circuit that compares the count value with a set value N, and the coincidence detection circuit detects the coincidence of both. Then, the pulse output of the astable multivibrator is stopped. The output pulse period T of the astable multivibrator and the comparison value N supplied to the coincidence detection circuit can be set by registers R0 and R1, respectively.

  The inverter 53 receives the job execution signal JobOn input to the off-delay timer 10. When the current time t comes to the power saving transition time set in the weekly timer 12 for each day of the week, one pulse is output from the output terminal SO, and the N-shot multivibrator 51 responds to this in FIG. As shown, a pulse with period T is output.

  If the job is being executed, the output of the inverter 53 is at a low level, so the output of the AND gate 52 is maintained at a low level. When the job execution is stopped and the job execution signal JobOn transitions to a low level, the output of the inverter 53 transitions to a high level and the AND gate 52 is opened, and the output pulse of the N-shot multivibrator 51 is changed to the AND gate 52 and It passes through the OR gate 13 and is output as a pulse of the secondary power saving transition trigger signal ST, and the N-shot multivibrator 51 is reset by the falling edge of the output pulse of the AND gate 52.

  The control unit 21 shifts the image forming apparatus 20 to the power saving mode in response to the activation of the power saving shift trigger signal ST. In this power saving mode, for example, the heater of the fixing unit provided in the image forming unit 27 is turned off, the rotation of the hard disk, which is a component of the storage unit 24, is stopped, and the frequency of the clock to the CPU is lowered or Stop. When the clock is stopped, as a pre-processing for shifting to the power saving mode, the CPU state and the register contents are saved in the storage unit 24 so that the CPU can be restarted.

  With the above operation, the time T2 from the stop of job execution to the rise (activation) of the pulse of the power saving transition trigger signal ST becomes equal to or shorter than the cycle T. The time T1 in FIG. 8 is, for example, 20 minutes, whereas the period T is, for example, 10 seconds. After the job is stopped, it is possible to shift to the power saving mode in a short time.

  In general, the image forming apparatus 20 is rarely used after the set time for the power saving shift. Therefore, even if the image forming apparatus 20 is immediately shifted to the power saving mode in this way, the image forming apparatus 20 is subsequently moved within the time T1. There is almost no use after returning to the normal mode, and further power saving can be achieved without impairing usability.

  In the second embodiment of the present invention, the power saving mode transition retry circuit 50 of FIG. 1 is configured by a program provided in the control unit 21 and a CPU provided in the control unit 21 that executes the program.

  FIG. 4 is a schematic flowchart showing processing in this program. This process is an interrupt process started in response to a pulse from the output terminal SO. FIG. 5 is a time chart showing operations related to the processing of FIG. In the following, the step identification codes in FIG. 4 are shown in parentheses.

  (S0) The initial value 0 is substituted into the software counter i, and the value at the current time t is substituted into the variable t0.

  (S1) If a job is being executed, the process proceeds to step S2, and if not, the process proceeds to step S5.

  (S2) If t−t0 <T, the process returns to step S1, otherwise the process proceeds to step S3. This period T is the same as the period T in FIG.

  (S3) The software counter i is incremented by 1, and the value at the current time t is substituted into the variable t0.

  (S4) If i> N, the process of FIG. 4 is terminated. Otherwise, the process returns to step S1. This number setting value N is the same as N in FIG.

  (S5) A pulse is supplied to the OR gate 13 by setting one input terminal of the OR gate 13 to a high level for a certain time.

  The other points are the same as those in the first embodiment.

  According to the second embodiment, the same function can be achieved with a simple software configuration without including the circuit 50 having the hardware configuration shown in FIG.

  In FIG. 4, step S2 may be omitted and the value of N may be set to an appropriate large value, and N can be replaced with T * N = Tx. That is, N can be interpreted as a time in units of T, and the processing time of steps S1 to S2 in FIG.

  In the third embodiment, the configuration of FIG. 4 is further simplified based on such an idea, and FIG. 6 shows a flowchart thereof.

  (S0A) The value of the current time t is assigned to the variable t0.

  (S1) If the job is being executed, the process proceeds to step S2A; otherwise, the process proceeds to step S5.

  (S2A) If t−t0 <Tx, the process returns to step S1, otherwise the process of FIG. 6 is terminated.

  (S5) A pulse is supplied to the OR gate 13 by setting one input terminal of the OR gate 13 to a high level for a certain time.

  The other points are the same as those in the second embodiment.

  In the above, preferred embodiments of the present invention have been described. However, the present invention includes various modifications, and other configurations that realize the functions of the respective components described in the above embodiments are used. However, other configurations that would be conceived by those skilled in the art from these configurations or functions are also included in the present invention.

DESCRIPTION OF SYMBOLS 10 Off-delay timer 11 Rise detection circuit 12 Weekly timer 13 OR gate 20 Image forming apparatus 21 Control part 22 RTC
23 Operation Panel 24 Storage Unit 25 Scanner 26 Image Processing Unit 27 Image Forming Unit 28 Communication Interface 30 PC
40 network 50 power saving mode transition retry circuit 51 N-shot multivibrator 52 AND gate 53 inverter R0, R1 register ST power saving transition trigger signal ST0 retry signal R reset input terminal SO, RO output terminal t current time t0 time JobOn Job execution Signal T Period T1-T3 Time i Software counter

Claims (4)

An image forming apparatus including a power saving control unit that shifts the apparatus to a power saving mode based on activation of a power saving shift trigger signal activated at a set time and whether or not a job is being executed. The power control means
A time measuring means for measuring an elapsed time from the activation;
Time setting means for setting the time;
In response to the activation, if the elapsed time is within the set time and the job is not being executed, power saving transition control means for shifting the own apparatus to the power saving mode;
An image forming apparatus comprising: The time setting means sets the cycle and the number of times,
In response to the activation, the power saving transition control means determines whether or not a job is being executed every natural number multiple of the period not exceeding the set number of times. , Shift own device to power saving mode,
The image forming apparatus according to claim 1. The time setting means sets the cycle and the number of times,
In response to the activation, the power saving transition control unit determines whether or not the job is being executed within a time not exceeding the set number of times of the cycle. Shift the device to power saving mode,
The image forming apparatus according to claim 1. The time measuring means is an N-shot multivibrator that outputs up to N pulses of period T in response to the activation and until a reset pulse is supplied,
The time setting means is a register for setting the values of the period T and the N,
The power saving shift control means includes a logic circuit that outputs the output pulse of the N-shot multivibrator as a signal for shifting to power saving and the reset pulse only when the job execution signal is inactive.
The image forming apparatus according to claim 1.

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