JPH11153918A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which correctly detects whether a replaced fixing unit is unused (except the time when it is turned on for inspection) or not. SOLUTION: The image forming device has at the side of the fixing unit 11 a detection-only slide switch 1 which cannot be operated with fingers and the like. By switching the slide switch 1 to the inspection mode side to use a inspection mode, the fuse of the fixing unit 11 is physically separated. Then, the inspection mode is executed by the software of a CPU 2 and, after the completion of it, the device is turned on under a user mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus having an exchange type fixing unit.

[0002]

2. Description of the Related Art In image forming apparatuses such as copying machines and printers, exchangeable fixing units are widely used. That is, when the life of the fixing unit attached to the apparatus main body has expired, the fixing unit is replaced with a new fixing unit. Therefore, in the related art, a means for discriminating between the old and new fixing units in an image forming apparatus having an exchange type fixing unit has been used.

Further, a technique for managing the life of a replacement type fixing unit has been proposed. For example, JP-A-63-
Japanese Patent Application Laid-Open No. 8755 proposes a technique for securely managing the life of the fixing unit by clearing a life management counter when a new fixing unit whose fuse is not blown is set.

[0004]

However, in the prior art, since the heater of the fixing unit is turned on in a burning step at the time of inspection, there is a problem that a fixing unit that has just been burned is recognized as being used. is there.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of accurately detecting whether or not a replaced fixing unit is an unused product (except for burning during inspection). is there.

[0006]

To achieve the above object, the present invention is directed to an image forming apparatus having a replacement type fixing unit, which is used to discriminate between a new fixing unit and a new fixing unit attached to a main body. In the inspection mode, the fuse is turned off, and control is performed to detect whether or not the replaced fixing unit is an unused product except for burning in the inspection mode.

[0007] To achieve the above object, the present invention provides a second aspect.
The invention described in the first aspect is characterized in that, in the invention according to the first aspect, a switch for an inspection mode is provided, and the fuse is physically isolated when the switch for the inspection mode is switched to the inspection mode. It is.

[0008] In order to achieve the above object, a third aspect is provided.
According to the invention described in the first aspect, when a new fixing unit is mounted on the display means in the operation unit, the fact is notified.

According to another aspect of the present invention, the above object is achieved.
According to the invention described in the first aspect, a notifying means for notifying the end of the inspection mode is provided.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 4 are diagrams for explaining the first embodiment. FIG. 1 is a flowchart showing functions of software of the first embodiment. FIG. 2 is a control block of the first embodiment. 3 and 3 are simplified external views of the fixing unit, and FIG. 4 is a simplified equivalent circuit diagram.

In FIG. 2, two modes are selected by a slide switch 1 provided in the fixing unit (described later). The CPU 2 recognizes an arbitrary mode and is software-controlled by a program in the ROM 3. RAM4 is
Used for the working area of each mode. The pull-up resistor 5 and the pull-down resistor 6 are at H level,
An L level signal is generated. Reference numeral 7 denotes a bus.

In FIG. 3, the slide switch 1 is slidably provided in the switching window 12 on the side of the fixing unit 11 to the left and right. Slide switch 1
Is connected to the main body by a connector 13. The drawer connector 14 is for connecting the AC harness for heater and the DC harness of the fixing unit 11 to the main body. The fixing unit 11 includes a heater, a thermistor,
A temperature fuse (may be a thermostat), a heater roller, and the like are provided.

In FIG. 4, the equivalent circuit of the fixing unit includes a pull-up resistor 21, a contact interrupt 22, an off contact 23, an on contact 24, a fuse 25, a slide switch body 1a, and a slide switch knob 1b. In FIG. 4, the slide switch knob 1b is set to the right, and the voltage is at the H level (+ 5V). That is, an H level signal is generated at the connector 13 and sent to the CPU 2. This expresses the inspection mode.

In the inspection mode, since the fuse 25 is physically isolated, the off contact 23 is used as shown in FIG. The fuse 25 is mechanically isolated by a contact interrupt 22 connected to the slide switch knob 1b. That is, the contact interrupt 22 operates simultaneously with the slide switch 1.

In the present embodiment, the slide switch 1 is provided with a switching window 12 using a thin tool such as a knob driver.
It is supposed to be plugged in and switched. In other words, the switch cannot be operated by a finger or the like.

Next, the first embodiment will be specifically described. First, the operation of the main body (including the fixing unit) is previously confirmed in the manufacturing process. At this time, since the burning has already been performed, the heater is naturally turned on. An exception shall be made only at the time of this inspection, and the recognition of new products shall be maintained. As an example, as shown in FIG. 4, the fuse 25 is isolated using the slide switch 1.

The operation of the slide switch 1 is as follows.
As described above, this operation is performed using a thin tool such as a knob driver. In this way, the user or the like cannot easily cancel with a finger or the like. However, once fuse 25 is blown, it is used (used)
Therefore, this structure is adopted in order to prevent the fixing unit in a new state from being canceled (sliding the switch to the inspection mode side).

The slide switch 1 functions to isolate the fuse 25 by a mechanical action and at the same time to perform an electric action. An electric contact (off contact 23,
An ON contact 24) is provided, and two modes of the inspection mode and the user mode are provided.
Prepare one. At the time of inspection, of course, switch to the former. These two modes are distinguished as digital values (H level, L level) (H is defined as an inspection mode and L is defined as a user mode).

These selected modes are temporarily stored in the RAM 4 and an arbitrary mode is operated. Further, a setting is made so that the inspection mode is recognized by a software operation (that is, a signal is taken in by the CPU 2 and software control is performed).

It should be noted that a two-stage configuration is adopted in which the user mode is validated after recognizing that the inspection process has been completed by software (the software has recognized the inspection mode signal). In short, it is set by software so that it is impossible to start the fire in the user mode unless the inspection mode is finished (unless the inspection mode signal is recognized). Since it is assumed that only the user mode signal is used after the second time, it is set so that the request for the inspection mode is not performed again. This is because it will be an important function). In this way, care is taken to prevent the fuse 25 from being blown by mistake in the user mode at the time of inspection.

After the inspection, the slide switch 1 is returned to the original position, and the fuse 25 is connected. At this point, it is assumed that the burning is not performed until the user is installed.

The flow chart of FIG. 1 will be described below based on these conditions and the like. First, it is determined whether the signal is an inspection mode signal (S1). If NO, the heater control circuit is electrically locked (for example, AC is turned off by a triac or the like) and is disabled (S2). This prevents erroneous cutting of the fuse 25. If yes,
As the heater is turned on at the time of inspection, the heater control circuit electrically releases the lock (for example, turns on the AC by a triac or the like) and sets the heater to an enabled state (S3).

When the inspection mode is recognized by the software, the mode is switched to the user mode only (S4). That is, at this point, the request for the inspection mode signal is disabled (S5). After the inspection, the main body power is turned off, and the slide switch 1 is switched to the user mode.

The above is one embodiment of the present invention, but since the fuse cutting means and the recognition means by the user installation thereafter are not different from the prior art, the description of the structure and the like will be omitted. In the present invention, a new product is detected while securing an exceptional process of “burning at the time of inspection”.

FIGS. 5 to 7 are diagrams for explaining the second embodiment. FIG. 5 is a flowchart showing the functions of the software according to the second embodiment. FIG. 6 is a diagram showing the second embodiment. FIG. 7 is a diagram showing the display contents of the display panel of the operation unit.

As shown in FIG. 6, the second control block has an operation unit 8 added to the configuration of FIG. As shown in FIG. 7, a display panel 8a mounted on the operation unit 8 is provided.
Informs that the fixing unit 11 has been replaced with a new one. In the flowchart shown in FIG. 5, steps S11 to S1
In step 4, the same processing as steps S1 to S4 in FIG. 1 is performed.

Thereafter, the fact that the fixing unit 11 has been replaced with a new one is displayed on the display panel 8a (S15). This display is performed, for example, for 30 seconds (S1
6). That is, it is determined whether or not the timer has reached 30 seconds (S17), and if so, the display is turned off (S18),
The inspection mode request is disabled (S19). 30
If the time has not reached the second, the loop of S17 is repeated until the time reaches 30 seconds.

FIG. 8 is an external view of a fixing unit to which a mechanical indicator is added. A mechanical indicator 15 is added to the fixing unit 11. After the inspection, the slide switch 1 is switched to the user mode. In a structure similar to the contact interrupt, for example, a red marking becomes visible only when the mechanical indicator 15 is switched to the user mode.

The image forming apparatus of the present embodiment is provided with a slide switch 1 for inspection which cannot be operated by a finger or the like beside the fixing unit 11. When the slide switch 1 is switched to the inspection mode in the inspection mode, the fuse 25 of the fixing unit 11 is physically isolated. And CP
The inspection mode is executed by the software of U2, and after the completion of the inspection mode, the burning is performed in the user mode. The intended purpose is achieved by such a configuration and control.

[0030]

According to the first and second aspects of the present invention, it is possible to prevent a new product from being erroneously recognized as a second-hand product, and to ensure that the replaced fixing unit is an unused product (except for burning during inspection). By detecting whether or not there is, it is possible to detect a new fixing unit without being affected by burning during inspection.

According to the third aspect of the present invention, when a new fixing unit is mounted, the fact is notified that the replacement operation has been performed reliably.

According to the fourth aspect of the present invention, by displaying the inspection completed at the time of inspection (burning for performing an operation check), workability at the time of inspection is improved.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating functions of software according to a first embodiment.

FIG. 2 is a control block diagram according to the first embodiment.

FIG. 3 is a simplified external view of a fixing unit.

FIG. 4 is an equivalent circuit diagram.

FIG. 5 is a flowchart illustrating functions of software according to the second embodiment.

FIG. 6 is a control block diagram according to a second embodiment.

FIG. 7 is a diagram showing display contents of a display panel of an operation unit.

FIG. 8 is an external view of a fixing unit to which a mechanical indicator is added.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Slide switch 1a Slide switch body 1b Slide switch knob 2 CPU 3 ROM 4 RAM 5 Pull-up resistor 6 Pull-down resistor 7 Bus 11 Fixing unit 12 Switching window 13, 14 Connector 21 Pull-up resistor 22 Contact interrupt 23 Off contact 24 On contact 25 fuse

Claims (4)

[Claims] In an image forming apparatus having a replacement type fixing unit, a fuse is turned off in an inspection mode for identifying whether a fixing unit attached to a main body is new or old.
An image forming apparatus, wherein control is performed to detect whether or not a replaced fixing unit is an unused product except for burning in an inspection mode. 2. An image forming apparatus according to claim 1, further comprising an inspection mode switch, wherein the fuse is physically isolated when the inspection mode switch is switched to the inspection mode. . 3. The image forming apparatus according to claim 1, wherein when a new fixing unit is mounted on the display unit in the operation unit, the fact is notified. 4. The image forming apparatus according to claim 1, further comprising a notifying unit for notifying the end of the inspection mode.