JP2006047350A - Image forming apparatus - Google Patents

Abstract

An image forming apparatus capable of reducing a first print time or an image forming apparatus capable of reducing a load on a power supply circuit.
In an image forming apparatus having a sequence in which start timings of motors with large current consumption are not made the same, when the image forming apparatus is restarted immediately after the end of printing, the start times of the main motor and the scanner motor are set as described above. An image forming apparatus characterized in that it is shorter than a start timing sequence. An image forming apparatus comprising: means for switching a starting current setting resistance value of the main motor, wherein the switching timing is switched at the same time when the image forming apparatus is started from a normal standby and at a restart immediately after printing.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus provided with control of a startup sequence of motors used in a laser beam printer, a copying machine, and the like.

  Conventionally, in a printer, at the time of activation from standby, the drive unit in the apparatus is activated simultaneously according to a print instruction. Alternatively, a unit having a large current consumption, for example, a main motor and a scanner motor, is activated by changing the activation timing to such an extent that the image printing sequence is not hindered.

In addition, the setting of the starting current setting for the main motor and the like has only been a single setting.
JP-A-7-334039

  However, in the above-described conventional example, there is a state in which it is meaninglessly waiting for a time that does not actually need to be waited when controlling the main body.

  This is due to the fact that a very large current consumption is required to reduce the load on the power supply. For example, the main motor and the scanner motor are controlled at different start timings.

  In this control, the time required for starting the main motor, that is, the time during which the inrush current caused by starting the main motor flows is set to a certain time, and the scanner motor is started after this time has elapsed.

  This control eliminates the need for considering the inrush current at the time of starting the main motor and the sum of the inrush current at the start of the scanner motor as the power supply circuit, so that the electronic components for configuring the power supply circuit There is no need to improve the performance more than necessary.

However, when controlling the main unit, considering the above, even if the inrush current at the time of start-up becomes small, the start timing of the main motor start-up and the start-up time of the scanner motor are the same as when the inrush current is large. Because it is changing, it means waiting for meaningless times when you don't actually have to wait.
As a result, the time to start printing is wasted, and the first print time cannot be shortened.

  Accordingly, in view of the above, a first object is to propose an image forming apparatus capable of reducing the first print time.

  As another problem, since the setting of the starting current setting for the main motor or the like is only a single setting, in any case, the maximum current flows when starting the main motor.

  However, by providing a plurality of current detection resistors, the maximum current that flows to the main motor can be changed according to circumstances. This makes it possible to start the motor without unnecessarily consuming current.

  Therefore, in view of the above, a second object is to propose an image forming apparatus capable of reducing the load on the power supply circuit.

  In the present invention for achieving the first object described above, when the inrush current at the start-up becomes small in controlling the main body, the start timing of the main motor and the start-up time of the scanner motor are compared with the case where the inrush current is large. Control to start at different timings.

  Here, the case where the inrush current at the time of startup is small is, for example, at the time of reprinting immediately after printing. Immediately after printing, for example, the temperature of the fuser is high and the gear for driving the fuser is sufficiently familiar with grease, so the torque required to drive the fuser Has been reduced.

  When the torque is reduced, the inrush current flows for a shorter time even at the same motor starting current than at the first starting. In accordance with this, the time of the start timing of the scanner motor is shortened from the start timing of the main motor.

  As a result, there is no meaningless waiting time in the main body control sequence, and the first print time can be shortened.

  In the present invention for achieving the second object, the main motor is described here, but the state of the image forming apparatus used is provided by providing a plurality of resistors for setting the starting current. To switch the resistance.

  As a result, the maximum current value at the time of startup can be suppressed, and the load on the power supply circuit can be reduced.

  For example, the set current is set to two types, “large” and “small”. When printing is performed from a state where it has not been used for a certain period of time, the set current is set to “large”, and when printing is performed from the other state, that is, from a state where the time is short from the previous printing ( Hereinafter, control is performed so that the set current can be selected as “small”.

  As a result, it is possible to reduce the load on the power supply circuit without changing the start-up time of the main motor at the same time as the restart immediately after printing.

  The configuration of the present invention will be described below by arranging the above.

(1) An image forming apparatus that includes a motor for driving a recording medium, a photoconductor, a fixing device, and the like for a recording operation, and records image information on the recording medium using an electrophotographic process. In an image forming apparatus having a sequence that does not make the start timings of large motors the same,
An image forming apparatus characterized in that when the image forming apparatus is restarted immediately after the end of printing, the start time of the main motor and the scanner motor is made shorter than the start timing sequence.

  According to the present invention, by shortening the time of the start timing of the scanner motor from the start timing of the main motor, there is no meaningless waiting time in the main body control sequence, and the first print time can be shortened. Since the waiting time of the user is shortened, a user-friendly image forming apparatus can be provided.

  In addition, by providing a plurality of current detection resistors for the main motor, it is possible to set the start-up current according to the state of the image forming apparatus, and to reduce the load on the power supply circuit. In addition, it is possible to provide a useful image forming apparatus.

  Embodiments to which the present invention is applied will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a flowchart showing an embodiment of the present invention, and FIG. 4 is a diagram showing a configuration of a laser beam printer.

  First, a schematic operation of an electrostatic copying printer (generally called a laser beam printer) using a laser, which is taken up in this embodiment, will be described with reference to FIG.

  After the power is turned on, the printer 401 turns on the main motor 301 and performs multiple front rotations. By this multiple pre-rotation, the surface of the photosensitive drum 402 is neutralized, that is, a charging AC voltage is applied by the charger 404 and a reverse bias voltage of the transfer bias voltage is applied by the transfer device 406 to charge the surface of the photosensitive drum 402. Then, the transfer roller in the transfer unit 406 is cleaned in the same manner, and a transition is made to the standby mode. In the standby mode, an internal state such as whether paper 411 is loaded in the paper cassette 410 is always checked, and a controller (not shown) is informed whether printing is possible. When the controller is ready for printing, the controller starts a printing operation by sending a print start command to the printer 401 as necessary.

  In the printing operation, after receiving a print start command from the controller, the CPU (not shown) for engine control turns on the main motor 301, and then starts the temperature control of the fixing device 409. The device 404 and the transfer device 406 are turned on, and the surface potential of the photosensitive drum 402 is initialized by rotating the photosensitive drum 402, and the scanner motor 412 is turned on to start the rotation of the rotating mirror 413. When the initialization of the photoconductor 402 is completed, the fixing device 409 reaches an appropriate temperature, and the rotation of the rotary mirror 413 is stabilized, the paper 411 is fed from the paper cassette 410 by the paper feed roller 407, and the leading edge of the paper When the ink reaches the registration roller 408, the conveyance of the paper is once stopped and waits.

  In this state, the printer 401 requests the controller to send a sub-scanning direction synchronization signal (VSYNC signal). In response to this, the controller sends a VSYNC signal, and in addition to the main scanning direction synchronization signal (BD signal) from the printer 401. An image signal (video signal) is transmitted in synchronization. The laser beam reflected by the rotating mirror 413 actually forms a light image on the photosensitive drum 402 by the lens system 414 and the mirror 415. The optical image is then developed by the developing device 405 to become a toner image. By driving the registration roller 408, the toner image and the paper whose end has been aligned are transferred by the transfer unit 406, conveyed, fixed by the fixing unit 409, and discharged onto the paper discharge tray 416. .

  Based on the above configuration, the control timing of the main motor 301 of this embodiment will be described with reference to the flowchart of FIG.

The main switch of the printer 401 is turned on, pre-multi-rotation processing is performed (S101), a state where printing can be performed, that is, a standby state (S102), and a print instruction from the controller is awaited. In this standby state, a main body control CPU (not shown) waits for a print start command from the controller while monitoring various sensors in the printer (S103). When a print instruction is received from the controller, it is determined whether or not T ₁ msec or more has elapsed since the end of the printing operation (S104). If T ₁ msec or more, the start time difference between the main motor and the scanner motor is set to T ₂ msec. (S105) and image forming processing is performed (S106). When the image formation is completed, post-rotation processing is performed, the timer is reset and started (S107), and the process returns to the standby state (S102). On the other hand, if T ₁ msec or more is determined after the end of the printing operation (S104), if it is T ₁ msec or more, the start time difference between the main motor and the scanner motor is set to T ₃ msec (S108). Then, an image forming process is performed (S106). When the image formation is completed, post-rotation processing is performed, the timer is reset and started (S107), and the process returns to the standby state (S102).

  This is shown in the timing chart of FIG.

As an example, the judgment time of the timer that starts from the end of the printing operation is 60000 msec (T ₁ msec in S104), the start time difference between the main motor and the scanner motor is 1000 msec (T ₂ msec) and 200 msec (T ₃ msec), It is assumed that the time until the rotation of the scanner motor is stabilized is 6000 msec.

  As described above, when a print instruction is received from the controller, if a time of 60000 msec or more has elapsed since the end of the previous print, the start time difference between the main motor and the scanner motor is set to 1000 msec. In this case, the time from when the main motor is turned on until the paper can be fed is 7000 msec.

  On the other hand, if the time of less than 60000 msec has elapsed since the end of the previous printing, the start time difference between the main motor and the scanner motor is set to 200 msec. In this case, the time from when the main motor is turned on until the paper can be fed is 6200 msec.

  Therefore, in both cases, the time difference from the print instruction to the paper feeding can be 800 msec. In the case of a so-called medium speed machine, this time difference substantially corresponds to a time during which one page can be printed.

  By controlling as described above, there is no meaningless waiting time in the main body control sequence, and the first print time can be shortened.

(Second embodiment)
Embodiments to which the present invention is applied will be described below with reference to the drawings.

  FIG. 3 is a block diagram of a motor drive circuit showing an embodiment of the present invention.

  301 is a motor unit, 302 is a motor driving IC, 303 is a motor, 304a and 304b are resistors, 305 is a transistor for turning on / off the resistor 304b, 306 is a motor on / off signal, 307 is a current detection resistor 304a , 308 is an engine board of the image forming apparatus, and 309 is a control CPU (hereinafter referred to as CPU) of the image forming apparatus.

  When an ON signal 307 is input from the CPU 309, the main motor 303 causes a current to flow to the motor 303 by the drive IC, and the motor 303 starts to rotate. At this time, the maximum current flowing to the motor is converted into a voltage by the current detection resistors 304a and 304b and monitored by the driving IC. When this value becomes larger than the internal reference voltage, the current flowing to the motor 303 is reduced.

  In this way, the current flowing to the motor 303 can be set by the resistance values of the current detection resistors 304a and 304b.

  Here, if the circuit is configured such that one side can be turned on / off by the transistor 305, when the transistor 305 is on, the current detection resistance depends on the combined resistance value of 304a and 304b. Conversely, when the transistor 305 is off, it depends on the resistance value of only 304a. Therefore, two types of current detection can be performed for the same reference voltage.

  Now, when a certain time has elapsed since the previous printing of the image forming apparatus, the main body is cold, and the grease for lubrication applied to the gears is hardened. Is getting bigger. For this reason, in order to rotate the motor 303, a big torque is required. Therefore, when a print instruction is received in such a state, the CPU 309 turns on the transistor 305 and sets the current detection resistance value to be small. That is, the value of the current flowing through the motor 303 can be set large.

  On the other hand, when the state of the image forming apparatus has not been printed since a certain period of time has elapsed, the main body is warm, so that the grease for lubrication applied to the gear is sufficiently familiar, Torque is small. For this reason, a large torque is unnecessary to rotate the motor 303. Therefore, when a print instruction is accepted in such a state, the CPU 309 turns off the transistor 305 and sets a large current detection resistance value. That is, the value of the current flowing through the motor 303 can be set small.

  As described above, even if two types of current detection are performed, the operation of the image forming apparatus can be performed without changing the time from when the print instruction is received until the start of printing.

  Further, the current is not consumed unnecessarily, which is beneficial for energy saving.

2 is a flowchart illustrating a processing procedure in the image forming apparatus according to the first exemplary embodiment. The timing chart of Example 1 is shown. The motor drive circuit structure of Example 2 is shown. 1 illustrates a configuration of an image forming apparatus according to an embodiment.

Explanation of symbols

301 Motor unit 302 Motor driving IC
303 Motor 304a Resistor 304b Resistor 305 Transistor 309 Main unit control CPU

Claims (3)

An image forming apparatus that includes a motor for driving a recording medium, a photoreceptor, a fixing device, and the like for a recording operation, and that records image information on the recording medium using an electrophotographic process, and has a large current consumption. In an image forming apparatus having a sequence that does not have the same start timing,
An image forming apparatus characterized in that when the image forming apparatus is restarted immediately after the end of printing, the start time of the main motor and the scanner motor is made shorter than the start timing sequence. In an image forming apparatus comprising a motor for driving a recording medium, a photoreceptor, a fixing device, etc. for a recording operation, and recording image information on the recording medium using an electrophotographic process.
An image forming apparatus comprising a plurality of resistors for setting a starting current of a main motor, and starting by switching a starting current setting resistance value according to a state of the image forming apparatus.   3. The image forming apparatus according to claim 2, wherein the timing for switching the starting current setting resistance value of the main motor is switched simultaneously when the image forming apparatus is started from a normal standby and at the same time when the image forming apparatus is restarted immediately after printing. .

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