JP2554330B2 - Self-diagnosis device for image forming device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a self-diagnosis device for detecting an abnormality of switches for timing operation of an image forming apparatus.

(Prior Art) In a copying machine, various mechanisms are provided with switches in order to set timings for copying operations, etc., and information from these switches serves as the center of a microcomputer circuit for controlling the entire device. It is designed to be input to the CPU, which is a microprocessor. The switches of the various mechanisms mentioned above are position detection switches for the document table,
Examples include a transfer paper discharge switch, a cassette paper presence / absence detection switch, a resist switch, and a stack switch for manual paper feeding.

By the way, conventionally, the development, design,
It is desired to realize a method capable of easily and promptly detecting the above-mentioned abnormality of switches at the manufacturing inspection stage, failure diagnosis by a service person in the market, and repair.

By the way, conventionally, in order to check the abnormality of the above switches from the outside, it is troublesome to pull out wiring from each switch or take out a signal from the microcomputer to the outside and use a measuring instrument such as a tester or a synchroscope. Was needed.

Further, as shown in Japanese Patent Laid-Open No. 60-84551, a test mode different from the copy mode is provided, and the logic of each input signal is discriminated according to the number of ten keys for setting the number of copies, and the copy is performed. There is a display for displaying the number of sheets to detect an abnormality. However, in the method disclosed in the above publication, it is impossible to see the states of a plurality of switches in a series of process operations.
Still, there is a problem that it takes a lot of time and labor to detect an abnormality.

(Object of the Invention) The present invention solves the above-mentioned problems, and checks the state of each switch of an apparatus for forming an image, that is, self-definition of an apparatus for forming an image capable of easily and quickly knowing abnormality detection. An object is to provide a diagnostic device.

(Structure of the Invention) The present invention has an image having a test mode for diagnosing whether or not there is an abnormality in at least two or more of detection outputs of various switches for timing an image forming operation and a heater control temperature of a fixing device. A self-diagnostic device for forming devices, which is an indicator composed of a plurality of segments, in which each segment is connected in correspondence with an output line from each of the switches and the temperature detecting element, and a test mode is designated. And an image forming operation is performed, and during the image forming operation, each switch and the detection output are guided to the corresponding segment of the display unit, and the corresponding segment according to the state of each switch and the detection output. Is turned on or off.

By this method, when each switch, temperature detection element, etc. are not performing a predetermined operation during the image forming operation in the test mode, the segment of the specific display device corresponding to the switch deviates from the predetermined display state. So
Immediately after the display, a plurality of abnormal points are simultaneously notified.

(Embodiment) FIG. 1 shows the overall configuration of a copying machine to which the self-diagnosis apparatus according to the present invention is applied, where 1 is a movable original table (optical system) on which an original provided on the upper surface of the machine is placed. Scanning member), 2 is a process unit mounted in the machine body for performing image formation by an electrophotographic method.
Is composed of a photoconductor 3, a main charging device 4, a developing device 5, a cleaning device 6, and the like. Reference numeral 7 is an exposure lamp for exposing and scanning an original, 8 is a condenser lens, 9 is a transfer device for transferring the toner development formed on the photoconductor 3 onto a transfer paper, 10 is a fixing device for fixing the transferred image, and 11 is in the machine. Cooling fan for cooling, 12 is a cassette containing transfer paper, 13 is a manual paper feed tray, 14 is a paper discharge tray, 15 is a paper feed roller for feeding paper from cassette 12, and 16 is manual paper feed. Reference numeral 17 denotes a roller pair, 17 a pair of transport rollers, 18 a pair of registration rollers for timing secondary sheet feeding, 19 a transport belt, and 20 a pair of discharge rollers for discharging the transfer sheet after fixing.

Furthermore, the timing of controlling the copying operation is set, and
Switches 21a and 21b for detecting the position of the document table 1 and a discharge switch 22 for detecting the discharge of the transfer sheet are provided as switches for detecting the state of each part and obtaining a signal to be displayed on the display on the operation panel. , A paper detection switch 23 for detecting the presence or absence of transfer paper in the cassette 12, a registration switch 24,
A stack switch 25 for manual sheet feeding and a thermistor (temperature detecting element) 26 for detecting the temperature of the heat roller 10a of the fixing device 10 and controlling the temperature are provided.

Further, as shown in FIGS. 1 and 2, on the lower surface of the manuscript table 1, one switch 21a of the switches arranged in parallel is provided.
Facing each other, three projections 31, 32, 33 for operating the switch in the moving direction of the original table 1, and two projections 34, 35 for operating the switch facing the other switch 21b, respectively. It is provided at the position. The protrusion 31 is for timing the leading edge of the document, the protrusion 32 is for detecting the home position, and the protrusions 33 and 35 are the document table 1.
Is for detecting overrun, and the projection 34 is for timing of exposure start. Instead of moving the document table 1, a system in which an optical system performs exposure scanning may be used.

Since the operation of the copying machine having the above-mentioned configuration in the normal copying mode is well known, its detailed description is omitted here.

FIG. 3 shows a circuit configuration of the self-diagnosis device according to the present invention. The CPU 41 in the microcomputer circuit controls the entire normal copy mode and the test mode which is a feature of the present invention. This is a result of comparing the ON / OFF signals of the switch group 42 having the above various switches and the detection output of the thermistor 26 with a predetermined value to the CPU 41 by the comparison circuit 43, and an abnormality such as disconnection or short circuit of the thermistor. Error output signal is input when this CPU4
The output of 1 drives the display unit 45 including a 7-segment LED or the like via the decoder 44.

Then, each segment (digit) a of this indicator 45,
b, c, d, e, f, g are the above switches 21a, 21 by the decoder 44.
b, 22, 23, 24, 25 and the thermistor 26 are configured to have a corresponding relationship with each of the error outputs, and each digit lights up when the above switches are ON (signal level is LOW) and there is an error output. However, each switch is set to OFF (signal level is HIGH) and turned off when there is no error output. The relationship between lighting and extinguishing may be reversed. Further, the display device 45 may also serve as a device for displaying the number of copies on the operation panel.

The operating procedure in the test mode by the CPU 41 is the 4th.
As shown in the flow chart in the figure, when there is a signal input to the input port of the CPU 41 (step S ₁ ), the signal level of each input port is checked (step S ₂ ), where the individual switches of the switch group 42 are if ON (LOW) digit display 45 corresponding lights (step S _3), the digit of the display 45 each switch corresponding if OFF (HIGH) of the switch group 42 is turned off (step S ₄ ), and thereafter, the same routine is repeated at a constant cycle by returning to step S ₁ .

The self-diagnosis method using the above configuration will be described in more detail below.

Now, for example, at the time of repair and inspection of a copying machine, to check whether or not various switches are normally operable, the normal copying operation is performed and the test mode is set. As a result, the switches are sequentially turned on in accordance with the movement of the document table 1, the feeding of the transfer paper, and the conveyance, and the respective digits of the display unit 45 are sequentially operated in synchronization with the switches.
Corresponding ones will light up, but if they do not work properly and there are abnormal switches, the corresponding ones will not light up. By checking this, the switches 21a, 21b, 22 ~
It is possible to immediately determine which one of 25 and the thermistor 26 is out of order.

That is, the first step of investigating the cause of the malfunction, that is, the switches and thermistors can be easily performed by confirming that the turning on / off of the digit deviates from the expected operating state at a predetermined timing. You can

Note that the switches to be inspected are not limited to those in the above embodiment, and may include switches related to the mechanism necessary for the copying operation, and at least,
It suffices that at least one detection signal among them is input to the CPU 41. Further, by also using an ordinary copy number display as the display 45, the number of signal lines can be reduced and the structure can be greatly simplified.

(Effects of the Invention) As described above, according to the present invention, a normal image forming operation is performed in the test mode, and various switches for controlling the timing of the image forming operation obtained in this operation and heater control of the fixing device are controlled. Since the detection output of the temperature detection element for each is displayed on the corresponding segment in the display form according to their state, it can be easily confirmed by confirming that the segment deviates from the predetermined operating state. In addition, it is possible to immediately know the abnormality of the corresponding switch or the temperature detecting element at the same time, and it is possible to greatly contribute to the efficiency improvement of the cause investigation of the operation failure.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a copying machine to which the self-diagnosis apparatus according to the present invention is applied, FIG. 2 is a layout diagram of protrusions and switches of a document table of the copying machine, and FIG. 3 is a circuit configuration of the self-diagnosis apparatus. FIG. 4 and FIG. 4 are flowcharts showing the operating procedure in the test mode. 1 ... original table, 21a, 21b ... original table position detection switch, 22 ... ejection switch, 23 ... paper detection switch, 24 ... registration switch, 25 ... stack switch, 26 ... thermistor (temperature detection Element), 41 ... CPU, 4
4 …… Decoder, 45 …… Display, a, b, c, d, e, f, g …… Segment.

Front Page Continuation (72) Inventor Junichi Takamatsu 1-22 Tamatsukuri, Higashi-ku, Osaka Mita Engineering Co., Ltd. (72) Inventor Yukihiro Aikawa 1-2-2 Tamatsukuri, Higashi-ku, Osaka Mita Engineering Co., Ltd. (56) References JP-A-55-79464 (JP, A) JP-A-60-149054 (JP, A) JP-A-57-141652 (JP, A) JP-A-60-19165 (JP, A) JP-A-59-159181 (JP, A) JP-A-62-201475 (JP, A) JP-A-60-84551 (JP, A) Practical application Sho-58-188659 (JP, U)

Claims (1)

(57) [Claims] 1. An image forming apparatus having a test mode for diagnosing whether or not there is an abnormality with respect to at least two or more of detection outputs of various switches for timing an image forming operation and a heater control heater of a fixing device. Self-diagnosis device of the present invention, which is an indicator comprising a plurality of segments, in which each segment is connected corresponding to an output line from each of the switches and the temperature detecting element, and when a test mode is designated, an image is formed. The operation is performed, and during the image forming operation, each switch and the detection output are guided to the corresponding segment of the display unit, and each switch and the detection output are turned on or off depending on the state. A self-diagnosis apparatus for an image forming apparatus, characterized in that the display state is any one of the above.