JP2003307888A - Image formation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a plurality of A/D ports to one while a plurality of the A/D ports for inputting the detected results of a plurality of current detection means for detecting the operation timing and disconnection errors of a plurality of clutches and solenoids are conventionally required. <P>SOLUTION: An image formation device comprises: the current detection means of a plurality of the clutches or the like; a current addition means for adding a plurality of current detection signals; an A/D input means for acquiring a current added value obtained by the current addition means in an A/D converter; and a timing generation means for driving a plurality of the clutches or the like. From the timing of the timing generation means and data acquired from the A/D input means, the respective current values of a plurality of the clutches are detected. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, and more particularly to control of an electromagnetic clutch, an electromagnetic solenoid and the like.

[0002]

2. Description of the Related Art FIG. 9 illustrates an image forming apparatus such as a laser beam printer or a laser fax machine, which has a light source unit, a cylindrical lens, a scanner motor having a rotary polygon mirror, an imaging lens, a BD detector and the like. The laser light emitted from the scanner unit 61 forms an image on the photoconductor 62 on the rotating drum. The photoconductor 62 whose latent image has been exposed by the laser is visualized by the developing unit 63 filled with the developer, and is transferred to the recording paper 64 supplied from the cassette 67 at the position of the transfer belt 65, and then the fixing device 66. The toner is fixed in and is finally discharged to a discharger (not shown). In such an image forming apparatus, a plurality of electromagnetic clutches for transmitting power from the main drive motor are
For example, it is installed in the paper feed unit and the registration unit. Further, for example, a plurality of electromagnetic solenoids for switching between upper and lower two types of mechanical mechanisms are installed in, for example, the paper feed unit and the paper discharge unit. Current is detected to detect the operation timing of these electromagnetic clutches and electromagnetic solenoids or to detect errors such as disconnection. In order to detect the operation timing of a plurality of electromagnetic clutches and electromagnetic solenoids, or to detect an error such as disconnection, a plurality of currents are detected.

For example, a block diagram of a configuration example of current detection in a conventional example using two electromagnetic clutches is shown. Two
An image control unit 1 is an electric circuit unit that controls the entire image forming apparatus.

Reference numerals 2 and 3 are an electromagnetic clutch A and an electromagnetic clutch B. Electromagnetic clutch A2 and electromagnetic clutch B
It is the CPU 1 that controls the entire operation including the control of the image control unit 21 that controls the operation timing of No. 3.
The electromagnetic clutch A drive means 4 and the electromagnetic clutch B drive means 5 are drive circuits that actually drive the electromagnetic clutch A2 and the electromagnetic clutch B3. 6 and 7 are
The electromagnetic clutch A current detecting means and the electromagnetic clutch B current detecting means, for example, the current of the electromagnetic clutch is passed through a low resistance connected in series, and the current can be calculated by measuring the voltage value of the low resistance. it can. The current values obtained by the electromagnetic clutch A current detecting means 6 and the electromagnetic clutch B current detecting means 7 are, for example, when it is desired to detect the operation timing, because it is desired to know the current value which changes from moment to moment.
1 is input to the A / D converter port. The A / D converter port of the CPU 1 has, for example, an 8-bit A / D
In the case of the converter port, the state of the current can be recognized by 8-bit digital data from a minimum of 0 to a maximum of 255.

[0005]

However, in the conventional embodiment, as shown in FIG. 6, if it is desired to detect the currents of the two electromagnetic clutches, the two A / D ports have a plurality of electromagnetic clutches or electromagnetic clutches. If it is desired to detect the current of the solenoid, a plurality of A / D ports are required. The number of circuits in the A / D input port is larger than other I / O ports,
Since the cost increases, multiple A / D input ports are multiplexed into one A / D in one chip CPU.
Even if the converter performs A / D conversion, it takes A / D collection time to perform A / D conversion while sequentially multiplexing a plurality of A / D ports. For example, it is general that only four or eight are installed. However, in the image forming apparatus,
For example, in addition to current detection of these electromagnetic clutches or electromagnetic solenoids, A / A is used for laser control, heater temperature control, etc.
As many D input ports are used, limited to 4 or 8
I've run out of individual caps. Therefore,
A solution for a device that requires a limited number of 4 or 8 input ports and more A / D input ports is shown.
For example, assume that there are only eight A / D input ports and the number of input ports that require A / D input ports is nine. Since one A / D input port is insufficient, the current detection of the electromagnetic clutch A and the electromagnetic clutch B may be detected by one A / D input port. 7 and 8 are explanatory views in which the A / D input ports other than the electromagnetic clutch A2 and the electromagnetic clutch B are not shown. FIG. 7 is a block diagram, for example,
After completing the operation of the two electromagnetic clutches, P
The structure driven by WM is shown. 9 and 10 are electromagnetic clutches A
The PWM drive means and the electromagnetic clutch B PWM drive means. As shown in FIG. 8, when the current rises and the operation is completed, the PWM drive is performed to reduce the current value. Now, in order to detect the current detection of the electromagnetic clutch A and the electromagnetic clutch B with one A / D input port, two inputs are multiplexed and input to one A / D input port. SW11 and SW12 are analog SWs for this multiplexer.

When CONTSW is High, SW1
When only 1 is turned on and the current of the electromagnetic clutch A is input to the A / D input port and CONTSW is Low, SW
Only 12 is turned on, and the current of the electromagnetic clutch B is input to the A / D input port. In this way, the number of required A / D input ports is the A / D prepared for the one-chip CPU 1.
When the number of input ports was exceeded, it was handled by multiplexing using an analog SW or the like. However, the cost of analog SW for multiplexing increases,
There is a drawback that the number of output ports for outputting the CONTSW signal for controlling the analog SW is increased and the cost is increased.

The present invention has been made in view of the above problems, and has a simple structure and an analog SW for multiplexing.
An output port for outputting a CONTSW signal for controlling the analog SW is unnecessary, and it is possible to suppress an increase in cost. Specifically, it has a means for adding the current values of a plurality of electromagnetic clutches or electromagnetic solenoids, and the current value added by the adding means is input to the A / D input port. By considering which electromagnetic clutch current is changing in consideration of the operation timing, one A / D
The problem was solved by making it possible to recognize the current value of each electromagnetic clutch or electromagnetic solenoid even if a current value obtained by adding the current values of a plurality of electromagnetic clutches or electromagnetic solenoids is input to the input port.

[0008]

The present invention has solved the above problems by having the following constitution.

(1) In an image forming apparatus which conveys a recording paper on which an image formed by the image forming means is printed, a means for driving a plurality of electromagnetic clutches and / or electromagnetic solenoids, a plurality of electromagnetic clutches, and / Or current detection means for detecting the drive current of the electromagnetic solenoid, A / D conversion means for A / D conversion of the current detected by the current detection means, and the result of the A / D conversion means, the electromagnetic clutch And / or an image forming apparatus having drive control means for controlling the drive of the electromagnetic solenoid,
In particular, it has a current adding means for adding drive currents of a plurality of electromagnetic clutches and / or electromagnetic solenoids, and the added current value obtained by the current adding means is fetched by the A / D converting means, and the A / D An image forming apparatus characterized in that drive control is performed according to the result of the conversion means.

(2) The image forming apparatus according to claim 1, wherein the current detecting means and the current adding means have a current detecting and adding means that realizes the current detecting and adding means by a single circuit.

(3) In an image forming apparatus which conveys a recording paper on which an image formed by the image forming means is printed, a driving means for driving a plurality of electromagnetic clutches and / or electromagnetic solenoids, and a plurality of electromagnetic means. PWM driving means for PWM driving the clutch and / or the electromagnetic solenoid,
Current detection means for detecting driving currents of a plurality of electromagnetic clutches and / or electromagnetic solenoids, current adding means for adding driving currents of a plurality of electromagnetic clutches and / or electromagnetic solenoids, and current adding means A / D conversion means for A / D converting and adding the added current value;
In the image forming apparatus that controls the drive of the electromagnetic clutch and / or the electromagnetic solenoid according to the result of the D conversion means,
An image forming apparatus, wherein the PWM operation of the other electromagnetic clutch and / or the electromagnetic solenoid is prohibited when the driving of the one electromagnetic clutch and / or the electromagnetic solenoid is started.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIGS. 1 and 2 show an embodiment of the present invention. 1 is a block diagram of a first embodiment of the present invention, in which an image control unit 21, an electromagnetic clutch A2, an electromagnetic clutch B3, a CPU 1, an electromagnetic clutch A driving means 4, an electromagnetic clutch B driving means 5, an electromagnetic clutch A current detecting means. 6. The electromagnetic clutch B current detecting means 7 is the same as in the conventional embodiment.

The current adding means 8 is newly added in the present invention. The current adding means 8 is the SW of the conventional embodiment.
It is installed in place of the multiplexer composed of 11 and SW12.

The details of the embodiment of the present invention will be described with reference to the timing chart of FIG. FIG. 2 shows drive control signals (CLA, CLB) and current waveforms (ICLA, ICLB) of the electromagnetic clutch A2 and the electromagnetic clutch B3. For example, ICL
When the waveform of A is closely observed, it rises with a predetermined time constant t (= L / R) at the rise of the current, but after becoming flat once, the operation is performed in two more steep rises. This is because the electromagnetic clutch operates, the magnetic resistance of the magnetic circuit decreases, and L (inductance) decreases. As L becomes smaller, the time constant t also becomes smaller and the rising becomes steeper. It is possible to estimate whether the operation of the electromagnetic clutch is completed at the timing when the current waveform becomes steep. In this way, by monitoring the current waveform,
The timing of the electromagnetic clutch operation is known, and the sequence of operations can be set up faster and more accurately. Also,
By monitoring the current waveform, it is possible to detect an electromagnetic clutch failure or the like due to damage of the wire material of the electromagnetic clutch. An example of an image forming apparatus having a plurality of such electromagnetic clutches is shown in FIG. 2, and the result of adding two current values of the electromagnetic clutch A2 and the electromagnetic clutch B3 by the current adding means 8 is ICLA + ICLB. As described above, even if a plurality of electromagnetic clutches and electromagnetic solenoids are used, they are often operated in different sequences. In this case, since the CPU 1 recognizes which one of the plurality of electromagnetic clutches is being driven, it is possible to infer which electromagnetic clutch has the added current value. . As described above, even the current adding means 8 installed in place of the multiplexer composed of SW11 and SW12 of the conventional embodiment can be realized with the same structure as that of the conventional embodiment and with a low cost and a simple configuration.
In the present embodiment, the electromagnetic clutch A current detecting means 6, the electromagnetic clutch B current detecting means 7, and the current adding means 8 are separately configured, but when the current detecting means is constituted by an operational amplifier or the like, they are combined into one. I don't mind. In other words, if the current-voltage conversion, which is a plurality of current detection means, and one current addition means are configured by one operational amplifier, a simpler and cheaper configuration can be realized.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS. 3, 4, and 5. FIG. 3 is a block diagram of the present invention. In the present invention, as shown in FIG. 4, the operations of the electromagnetic clutch A and the electromagnetic clutch B are overlapped, and further, after the operation of the electromagnetic clutch is finished, the current value is reduced,
Switching to PWM control. In FIG. 3, 9, 10
Is an electromagnetic clutch APWM control means, an electromagnetic clutch BP
It is a WM control means and is controlled under the control of the CPU 1. In the case of an electromagnetic clutch, a large amount of driving current is required because an operating force is required at the beginning of operation, but when the operation is completed
Since it is possible to hold even a smaller current, it is possible to operate by PWM. When the operations of the electromagnetic clutch A and the electromagnetic clutch B are overlapped with each other and, moreover, the operation of switching to the PWM control for reducing the current value after the operation of the electromagnetic clutch is simply added as in the first embodiment, Figure 4
Current addition signal ICLA + ICLB. When the operation timing is monitored by the current addition signal ICLA + ICLB, the electromagnetic clutch A2 is observed at Ta and the electromagnetic clutch B3 is observed at Tb. Although there is no problem in Ta when observing the electromagnetic clutch A2, in the period of Tb when observing the operation timing of the electromagnetic clutch B3, since it overlaps with the PWM operation of the electromagnetic clutch A2, the current addition signal I
CLA + ICLB is affected by the PWM operation current of the electromagnetic clutch A2 and has a jagged and noisy waveform. With such a waveform, the completion of the operation cannot be estimated well, so in the second embodiment, the timing is changed to that shown in FIG. In the second embodiment, T for operating the electromagnetic clutch b3
Only during the period of b, the PWM operation of the electromagnetic clutch A2 is prohibited and full driving is performed. Such operation can be easily controlled by the CPU 1. According to FIG. 5, the current addition signal ICL
During the period of Tb of A + ICLB, the noisy and noisy waveform disappears, and the operation timing of the electromagnetic clutch B3 can be determined.

[0016]

As described in detail above, according to the present invention, a simple structure of providing a current adding means is used to provide an analog SW for multiplexing and an output port for outputting a CONTSW signal for controlling the analog SW. It became unnecessary and it became possible to suppress the increase in cost. Specifically, it has a means for adding the current values of a plurality of electromagnetic clutches or a plurality of parts such as electromagnetic solenoids, and the current value added by the adding means is input to the A / D input port. Alternatively, by considering which electromagnetic clutch current is changing in consideration of the timing of operating the electromagnetic solenoid, a plurality of electromagnetic clutches per one A / D input port or the current value of the electromagnetic solenoid, etc. Even if the added current value of a plurality of parts is input, it can be recognized as the current value of each electromagnetic clutch or electromagnetic solenoid.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a timing chart of the first embodiment of the present invention.

FIG. 3 is a block diagram of a second embodiment of the present invention.

FIG. 4 is a timing diagram of the second embodiment of the present invention.

FIG. 5 is a timing diagram of the second embodiment of the present invention.

FIG. 6 is a block diagram of conventional example 1.

FIG. 7 is a block diagram of a conventional second embodiment.

FIG. 8 is a timing chart of a second embodiment of the related art.

FIG. 9 is a configuration example of an image forming apparatus applied to an embodiment of the present invention.

[Explanation of symbols]

1 CPU 2 Electromagnetic clutch A 3 Electromagnetic clutch B 4 Electromagnetic clutch A drive means 5 Electromagnetic clutch B drive means 6 Electromagnetic clutch A current detection means 7 Electromagnetic clutch B current detection means 8 Current addition means 9 Electromagnetic clutch A, PWM control means 10 Electromagnetic clutch B, PWM control means 21 Image control unit 61 Sukiana unit 62 photosensitive drum 63 developer unit 64 recording paper 65 Transfer belt 66 fixer 67 cassettes

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // B65H 7/00 F16D 27/16 Z 3J057 F term (reference) 2H027 DA01 DE04 DE07 ED16 EE06 EF06 HA17 HA18 2H072 CA01 JA02 2H171 FA04 FA25 GA31 LA07 LA13 LA18 QA02 QA08 QB15 QB32 QC05 QC36 SA11 SA12 SA22 SA28 TB01 3F048 AA01 AB01 BB02 DA06 DC00 EB24 EB37 3F049 DA12 EA01 EA07 EA03 EA01 EA03 EA03 BB03 3J057 AFF

Claims (3)

[Claims] 1. An image forming apparatus which conveys a recording sheet on which an image formed by an image forming means is printed, a means for driving a plurality of electromagnetic clutches and / or electromagnetic solenoids, and a plurality of electromagnetic clutches and / or Alternatively, a current detection means for detecting the drive current of the electromagnetic solenoid, and A / D conversion of the current detected by the current detection means, and A / D conversion
In an image forming apparatus having a drive control means for controlling the drive of an electromagnetic clutch and / or an electromagnetic solenoid based on the result of the D conversion means and the A / D conversion means, in particular, a plurality of electromagnetic clutches and / or electromagnetic solenoids It has a current addition means for adding a drive current, the added current value obtained by the current addition means is taken in by the A / D conversion means, and drive control is performed according to the result of the A / D conversion means. Image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the current detecting unit and the current adding unit have a current detecting and adding unit that realizes the current detecting and adding unit by a single circuit. 3. An image forming apparatus which conveys a recording paper on which an image formed by the image forming means is printed, and a driving means for driving a plurality of electromagnetic clutches and / or electromagnetic solenoids, and a plurality of electromagnetic clutches. And / or PWM driving means for PWM driving the electromagnetic solenoid, current detecting means for detecting the driving current of the plurality of electromagnetic clutches and / or electromagnetic solenoids, and a plurality of electromagnetic clutches and / or
Alternatively, the current adding means for adding the drive current of the electromagnetic solenoid and the added current value obtained by the current adding means are referred to as A
In an image forming apparatus that controls the drive of an electromagnetic clutch and / or an electromagnetic solenoid based on the result of the A / D conversion unit that performs A / D conversion and capture, and driving of one electromagnetic clutch and / or electromagnetic solenoid An image forming apparatus characterized in that the PWM operation of the other electromagnetic clutch and / or the electromagnetic solenoid is prohibited at the time of rising.