JP2000122483A - Image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image recorder by which the operation of a sensor can be easily confirmed and a defective sensor can be identified, so that time and labor required for checking are relieved. SOLUTION: This device has a detecting means to which paper passing sensors 20 and 22, a reversing sensor 21, paper existence/absence sensors 80 and 81, a carrying tray fullness sensor 82, and a door open/close sensor 84, etc., are provided. Further, this device is provided with a storing means detecting and storing the initial condition of the sensor at the time of applying the power source and a comparing means comparing the sensor condition, or a storing means previously setting and storing the sensor condition, or an instructing means instructing the storing means to store the sensor condition, a storing means storing the sensor condition, a discriminating means discriminating that only one sensor among the plural sensors is in a changing state based on a comparison result, and a display means displaying the discriminated result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus having a self-diagnosis function for judging a failure of a component of an image forming apparatus using an electrophotographic process such as a copying machine or a laser printer.

[0002]

2. Description of the Related Art Conventionally, in this type of image recording apparatus, a door is provided for the occurrence of a jam or replacement of a unit such as a cartridge or a fixing device. For this purpose, a sensor such as a photo interrupter is provided, and several similar sensors are provided for detecting the presence / absence of paper and for detecting the paper transport position.

[0003] When a failure occurs in these sensors, a serviceman actually disassembles the image recording apparatus, examines the location of the failure, and replaces a failed component.

Similarly, during production, if any of these sensors is abnormal, the failure location is checked and the replacement of the failed component or
It is customary to carry out rewiring of connection and the like.

[0005]

However, in the above-mentioned conventional example, if a failure or a failure occurs due to a sensor, a serviceman cannot specify which sensor has a failure, and the entire unit cannot be specified. We are doing things such as exchanging. In addition, there is a problem that it takes time and effort for service personnel.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is possible to easily confirm the operation of a sensor and to specify a defective sensor. In addition, it is another object of the present invention to provide an image recording apparatus capable of easily shortening the time and labor for checking, because a defect of a sensor can be easily specified even at the time of checking at the time of production.

[0007]

The present invention can solve the above-mentioned problems by providing the following constitution.

(1) Detecting means for detecting presence / absence of a paper, a paper transport position, and an open / closed state of a door by using a sensor, and detecting an initial state of the sensor when power is turned on and storing an initial sensor state. Storage means, comparison means for comparing the sensor state of the detection means with the sensor state storing the initial state, and judging that only one of the plurality of sensors has changed from the comparison result by the comparison means An image recording apparatus comprising: a determination unit that performs the determination; and a display unit that displays a result of the determination.

(2) Storage means for setting and storing the state of the sensor in advance, detection means for detecting the presence or absence of paper, the paper transport position, and the open / closed state of the door using the sensor, and a sensor for the detection means Comparing means for setting the state and comparing the stored sensor state with the state; determining means for determining that only one of the plurality of sensors has changed from the comparison result by the comparing means; An image recording apparatus, comprising: display means for displaying the image.

(3) Detecting means for detecting the presence or absence of paper, the paper transport position, and the open / closed state of the door by using the sensor, instructing means for instructing to store the state of the sensor, and instructing the instructing means Storage means for storing a sensor state based on
Comparing means for comparing the sensor state of the detecting means with the stored sensor state; determining means for determining from the comparison result by the comparing means that only one of the plurality of sensors has changed; An image recording apparatus, comprising: display means for displaying a determination result.

[0011]

Embodiments of the present invention will be described below.

(First Embodiment) A first embodiment is shown in FIGS.
6 will be described.

FIG. 1 is a schematic vertical sectional side view of a laser printer as an example of an image recording apparatus according to the present invention. Reference numeral 1 denotes an upper cassette which contains recording paper SH as a recording medium. Reference numeral 3 denotes a paper feed roller for feeding the recording paper SH to a position where the registration roller 5 is provided. Reference numeral 2 denotes a lower cassette which, like the upper cassette 1, contains recording paper SH as a recording medium, and feeds the recording paper SH to a position where the registration roller 5 is provided by a paper feed roller 4. 81 indicates cassettes 1 and 2
And a photo interrupter sensor for detecting the presence or absence of the recording paper SH. The registration roller 5 is connected to the paper feed rollers 3 and 4 or the paper re-feed roller 19.
The recording paper SH fed from the printer is conveyed to the image recording unit at a predetermined timing. Reference numeral 6 denotes a primary charger for uniformly charging the photosensitive drum 11. Reference numeral 7 denotes a developing unit which performs jumping development of an electrostatic latent image formed on the photosensitive drum 11 by using, for example, one-component toner.

Reference numeral 8 denotes a transfer charger for transferring the developed toner image to the recording paper SH. Reference numeral 9 denotes a cleaner device that collects toner remaining on the photosensitive drum 11. Reference numeral 10 denotes a neutralization lamp that exposes the photosensitive drum 11 to neutralize residual charges. 12 is a laser unit and a scanner motor 13a
Irradiates the polygon mirror 13 rotating at a constant speed with laser light, and forms an image corresponding to the image information on the photosensitive drum 11 via the polygon mirror 13 serving as a return mirror. A fixing device 14 applies heat and pressure to the recording paper SH on which the transfer process has been completed to fix an image on the recording paper SH.

Reference numeral 15 denotes a flapper for controlling the conveying direction of the recording paper SH after the fixing process. Reference numeral 17 denotes a reversing roller, which rotates in a forward direction when the recording mode is one side, and rotates in a direction for discharging the recording paper SH after the fixing process. Further, when the recording mode is double-sided, the rear end of the recording paper SH that has rotated in the forward direction and has completed the fixing process passes through the reversing sensor 21, and immediately after the passing, the reversing roller 1
7, the recording paper SH is drawn into the machine again.
Reference numeral 18 denotes a relay roller, which relays the inverted recording paper SH to a position where the re-feed roller 19 is provided. A first feeding unit is constituted by the upper cassette 1, the lower cassette 2, the feeding rollers 3, 4, and the like, and a second feeding unit is constituted by the re-feeding roller 19, the relay roller 18, the reversing roller 17, and the like. Be composed. Reference numerals 20 and 22 denote paper path sensors for detecting the passing state of the recording paper SH. Reference numeral 23 denotes a loading tray, and the exit roller 16
The recording paper SH on which printing has been completed is driven by stacking and discharged.
Reference numeral 82 denotes a loading tray full sensor that detects the full loading state of the loading tray. An upper door 83 is used when a jam occurs or when a cartridge or a fixing device is replaced. A door open / close sensor 84 for detecting the open / closed state is provided.

Reference numeral 24 denotes a printer control device, which is a host computer 2 serving as an external device via an interface 26.
5 is connected to the laser unit 1 for receiving image information.
In addition to controlling the driving of the second and the like, the driving of each driver required for the printing sequence is controlled overall.

FIG. 2 shows the printer control device 2 shown in FIG.
4 is a block diagram showing the configuration of FIG. 4, and the same components as those in FIG. 1 are denoted by the same reference numerals. In this figure, 27
Is a main motor that drives the photosensitive drum 11, the paper feed rollers 3, 4, the reversing roller 17, the relay roller 18, the re-feed roller 19, and the like shown in FIG. Reference numeral 28 denotes a beam detector which receives a laser beam emitted from the laser unit 12 immediately before writing an image, and outputs a beam detection signal shaped into a horizontal synchronization signal. Reference numeral 29 denotes a solenoid clutch, which is the sheet feed rollers 3 and 4 and the reversing roller 1 shown in FIG.
7. Turn on / off the driving of the relay roller 18, the re-feed roller 19 and the like. A sensor group 30 includes the paper path sensors 20, 22 and the reversing sensor 21, the paper presence / absence sensors 80, 81, the full loading tray sensor 82, the door open / close sensor 84, and the like shown in FIG.

Reference numeral 24 denotes a one-chip microcomputer (CPU) 24d including a ROM 24a, a RAM 24b, a comparator 24c, and the like, and controls the main control of the printer controller 24. Reference numeral 32 denotes an image processing circuit which sends image information and a print control command from the host computer 25 to the CPU 24d which performs main control in a format and timing described in a printer sequence. A main motor drive circuit 33 controls the main motor 27 at a constant rotation speed. A polygon motor driving circuit 34 drives the polygon mirror 13 at a constant rotation via the scanner motor 13a. A laser drive circuit 35 modulates and emits laser light in accordance with image information input from the host computer 25. Reference numeral 36 denotes a beam detection circuit which shapes a beam detection signal output from the beam detector 28 to generate a horizontal synchronization signal. A solenoid clutch drive circuit 37 drives the solenoid clutch. Reference numeral 38 denotes a sensor input circuit which outputs a sensor output from the sensor group 30 to the CPU 24d which performs main control. A lamp driving circuit 39 turns on and off the static elimination lamp 10. Reference numeral 40 denotes a high-voltage control circuit, which includes a primary charger 6, a developing device 7, and a transfer charger 8.
Is applied with a predetermined light voltage. 41 is a fixing device control circuit,
The temperature of the fixing device 14 is controlled to a predetermined temperature. Reference numeral 90 denotes an LED drive circuit that indicates the state of the sensor. The LED 51 illustrated in FIG. 3 is mounted on the printer control circuit board, and emits light to indicate the state of the sensor.

Next, the image recording operation will be described with reference to FIGS.

First, the host computer 25 designates the paper feed port of the recording paper SH and the destination thereof to the printer control device 24.

If the host computer 25 always designates the destination as the stacking tray 23, single-sided recording is performed, and the sheet supply is designated by the sheet feeding from the upper cassette 1 and the lower cassette 2 and the re-feeding port. If the re-feed roller 19 and destination specification are alternately specified in the two areas of the re-feed area and the stacking tray area, duplex printing is performed. When the printer control device 24 receives a recording start command from the host computer 25, the recording paper S
The fixing unit temperature is individually set based on the H feeding and destination designation.

FIG. 3 is an explanatory diagram showing a detailed circuit configuration of the LED drive circuit 90 and the sensor group 30 of the present invention.

The LED drive circuit 90 has a base of the LED drive transistor 50 to the CPU 24d and an emitter of G
Connect the collector to the cathode of LED51 to ND, LE
The anode of D51 is connected to a power supply via a current limiting resistor 52. This circuit is a circuit for driving the LED 51, and is driven by driving the transistor 50.
To emit light. The circuit of the sensor group 30 will be described. Reference numeral 20D denotes a drive circuit of the paper path sensor 20.
The paper path sensor 20 is a photo interrupter. The photo interrupter includes a diode unit 101 and a phototransistor unit 102.
The cathode of 1 is connected to GND, and the anode is connected to a power supply via a limiting resistor 103. The phototransistor section 102 has an emitter connected to GND, a collector side divided into two parts, one to a power supply via a limiting resistor 104,
The other is connected to the CPU 24d via the limiting resistor 105. This circuit detects the state of the sensor by mechanically blocking and transmitting the photointerrupter (see FIGS. 4A and 4B). The high level is input to the CPU 24d in the case of light shielding (FIG. 4B), and the low level in the case of transmission (FIG. 4A). In addition, each sensor (paper path sensor 20, 2)
2. Inversion sensor 21, paper presence / absence sensors 80 and 81, stacking tray full sensor 82, and door open / close sensor 84 have similar drive circuits (paper path sensor drive circuits 20D and 22D, reversal sensor drive circuit 21D, paper presence / absence sensor drive). Circuit 8
0D, 81D, loading tray full sensor drive circuit 82D,
It is detected by a door open / close sensor driving circuit 84D). The CPU 24d has a built-in ROM 24a and a RAM 24b, and stores the state of the sensor when the power is turned on.
The data is read and stored in 24b, and the LED 51 is turned off.
Then, the state of the photosensors (paper path sensors 20, 22, reversing sensor 21, paper presence / absence sensors 80, 81, stacking tray full sensor 82, door open / close sensor 84) is detected, and the stored power-on sensor is detected. Is compared by the comparator 24c, it is determined that only one sensor has changed, the transistor 50 is turned off, and the LED 51 emits light.

The control of this embodiment will be described with reference to the flowchart of FIG. First, when the power is turned on (step S201), the state of each sensor when the power is turned on is stored in the RAM 24.
b is read and stored (S202), and the LED 51 is turned off (S203). Next, the state of each sensor is checked (S204) and compared with the data in the RAM 24b (S204).
205), if they match, the LED 51 is turned off (S20).
8) Return to S204 again. If they do not match, it is determined whether only one sensor has changed (S206). If only one sensor has changed, the LED 51 is caused to emit light (S20).
7), and return to S204 again. If not only one sensor but a plurality of sensors have changed, the LED 51 is turned off (S20).
8) Return to S204 again.

FIGS. 5A to 5D are schematic views showing the state of the sensor by simplifying FIG.

FIG. 5A shows an example of the state of the sensor when the power is turned on. The CPU 24d reads and stores the state of each sensor in the RAM 24b. And
The LED 51 shown in FIG. 3 is turned off. FIG. 5B is an example of a state in which the sensor flag of one of the sensors (in this example, the paper path sensor 20) is intentionally changed, and the sensor is normally changed. In this way, the state of the photo sensor is compared with the stored state at the time of turning on the power, and it is determined whether the state of only one sensor has changed. In that case, the transistor 50 is turned on and the LED 51 is turned on. Flash. The light emission of the LED 51 makes it possible to recognize that this sensor is normal. FIG. 5C shows an example of a failure state in which the sensor flag of one of the sensors (in this example, the paper path sensor 20) is intentionally changed and the state of the sensor does not change. In such a case, compared to the state at power-on,
Since the state of the sensor has not changed, the LED 51 remains off. When the LED 51 does not emit light, it can be recognized that the sensor is abnormal. FIG.
(D) is a sensor (in this example, paper path sensor 2)
This is an example of a case where the sensor flag of 0) is intentionally changed, and the states of both the paper path sensors 20 and 22 are changed accordingly. Paper path sensors 20 and 2
Such a state may occur in a case where the two signal lines are connected or contacted by mistake. In such a case, although the state of the sensor does not match as compared with the state at the time of turning on the power, the LED 51 remains off because a plurality of changes have occurred instead of a single change. This LED
When the sensor 51 does not emit light, it can be recognized that this sensor is abnormal.

With the above configuration, when the flags of the sensors are changed one by one, the LED 51 emits light when the changed sensor is normal while comparing with the sensor state at power-on. However, when the sensor is out of order, the state does not change even if the flag of the sensor is moved, so that the LED 51 remains off. Further, since the change of only one sensor is determined, the LED 51 remains off even in the case of an abnormality in which the state of a plurality of sensors is changed by the flag of one sensor. Therefore, by changing the flags of the sensors one by one, L
By checking the lighting of the ED 51, abnormality or failure of the sensor can be easily detected.

Note that the LED 51 emits light when the power is turned on, and may be turned off when one sensor is different from the state of the sensor when the power is turned on.

(Second Embodiment) The configuration of the second embodiment is as follows.
Although it is almost the same as the first embodiment, the state of the sensor at the time of turning on the power is read and stored in the RAM 24b in the first embodiment.
The state of the sensor is set and stored in "a" and is compared with this data.

The second embodiment will be described with reference to the flowchart of FIG. First, when the power is turned on (step S301), the LED 51 is turned off (S302). Next, the state of each sensor is checked (S303), and the ROM 2
The data is compared with the data of 4a (S304), and if they match, the LED 51 is turned off (S307), and the process returns to S303 again. If they do not match, it is determined whether only one sensor has changed (S305). If only one sensor has changed, the LED 51 is made to emit light (S306), and the process returns to S303 again. If not only one but a plurality of sensors have changed, the LED 51 is turned off (S307), and the process returns to S303.

With the above configuration, by comparing with the state of the sensor set and stored in advance,
When the sensor flag is changed one by one, the LED 51 emits light if the changed sensor is normal, but if the sensor is abnormal or malfunctions, the state does not change even if the sensor flag is moved. The LED 51 remains off. Therefore, by changing the flags of the sensors one by one and checking the lighting of the LED 51, it is possible to easily detect abnormality or failure of the sensor.

The LED 51 emits light when the power is turned on, and may be turned off when one sensor differs from a previously set and stored sensor state.

(Third Embodiment) The configuration of the third embodiment is as follows.
Although it is almost the same as the first embodiment, in the first embodiment, the state of the sensor is read and stored in the RAM 24b only when the power is turned on. However, in the third embodiment, not only when the power is turned on, but also when the sensor is turned on. When an instruction to store the state is received, the state of the sensor can be read and stored in the RAM 24b and compared with this data. As a method of instructing to store the state of the sensor, an instruction is given from an input from an operation panel (not shown) of the image recording apparatus or a switch (not shown) provided exclusively for the image forming apparatus.

The third embodiment will be described with reference to the flowchart of FIG. First, when the power is turned on (step S401), the state of each sensor is read and stored in the RAM 24b (S402), and the LED 51 is turned off (S4).
03). Then, it is checked whether there is an instruction to store the sensor state (S404). If there is an instruction, the process returns to S402, and the state of each sensor is newly read and stored in the RAM 24b (S402), and the LED 51 is turned off (S403).
If there is no instruction, the state of each sensor is checked (S40).
5), compare with the data in the RAM 24b (S40)
6) If they match, the LED 51 is turned off (S40).
9) Return to S404 again. If they do not match, it is determined whether only one sensor has changed (S407). If only one sensor has changed, the LED 51 is caused to emit light (S40).
8) Return to S404 again. If not only one sensor but a plurality of sensors have changed, the LED 51 is turned off (S40).
9) Return to S404 again.

With this configuration, the sensor state at that time can be stored at any time from the operation panel or the dedicated switch, and the sensor state can be changed one by one by comparing the stored sensor state. When the changed sensor is normal, the LED 51 emits light. However, when the sensor is out of order, the state does not change even if the flag of the sensor is moved, so that the LED 51 remains off. Further, since the change of only one sensor is determined, the LED 51 remains off even in the case of an abnormality in which the state of a plurality of sensors is changed by the flag of one sensor. Therefore, by changing the flags of the sensors one by one and checking the lighting of the LED 51, it is possible to easily detect abnormality or failure of the sensor.

The LED 51 emits light when the power is turned on or when the sensor state is stored, and may be turned off when the state of the stored sensor is different from that of one sensor.

[0037]

According to the present invention, it is possible to easily confirm the operation of the sensor and to specify the defective sensor, so that it is possible to eliminate the problem that the serviceman takes time and effort at the time of checking, and furthermore, to check at the time of production. Even at the time, since the defect of the sensor can be easily specified, the effect of similarly reducing the time and labor for checking can be exhibited.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional side view of a laser printer as an example of an image recording apparatus showing an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a printer control device 24.

FIG. 3 is an explanatory diagram showing a detailed circuit configuration of an LED drive circuit 90 and a sensor group 30.

FIGS. 4A and 4B are explanatory diagrams showing a mechanical state of a photointerrupter sensor.

FIGS. 5A, 5B, 5C, and 5D are schematic vertical cross-sectional views showing the arrangement and function of each sensor.

FIG. 6 is a flowchart showing the operation of the first embodiment.

FIG. 7 is a flowchart showing the operation of the second embodiment.

FIG. 8 is a flowchart showing the operation of the third embodiment.

[Explanation of symbols]

 20, 22 Paper path sensor 21 Inversion sensor 24a ROM 24b RAM 24d CPU 51 LED 80, 81 Paper presence / absence sensor 82 Loading tray full sensor 84 Door open / close sensor

Claims (3)

[Claims] 1. A detecting means for detecting presence or absence of a paper, a paper transport position, and an open / closed state of a door by using a sensor, and a memory for detecting an initial state of the sensor at power-on and storing an initial sensor state. Means, a comparing means for comparing a sensor state of the detecting means with a sensor state storing the initial state, and judging that only one of the plurality of sensors has changed from a comparison result by the comparing means. An image recording apparatus, comprising: a determination unit; and a display unit that displays a result of the determination. 2. A storage means for setting and storing a state of a sensor in advance, a detection means for detecting presence / absence of paper, a paper conveyance position, and an open / closed state of a door using the sensor, and a sensor state of the detection means Comparing means for setting and storing the state and comparing the stored sensor states; determining means for determining from the comparison result by the comparing means that only one of the plurality of sensors has changed; An image recording apparatus, comprising: display means for displaying. 3. A detecting means for detecting presence / absence of paper, a paper conveyance position, and an open / closed state of a door using a sensor; an instructing means for instructing to store a state of the sensor; Storage means for storing a sensor state based on the sensor state; comparison means for comparing the sensor state of the detection means with the stored sensor state; and only one of the plurality of sensors changes from a comparison result by the comparison means. An image recording apparatus, comprising: a determination unit that determines that the user is present; and a display unit that displays a result of the determination.