Abstract:
A system includes an image forming apparatus or copier, and a central controller for remotely determining a cause of malfunction of the copier. The copier includes a control unit including a self-diagnostic portion; a selection portion for setting the control unit to a self-diagnosis mode; and a communication device for, when the self-diagnosis mode is set, connecting the control unit with a communication line. The self-diagnostic portion includes a receiving section for receiving diagnostic information through the communication device; a diagnostic section for executing self-diagnosis against the copier, on the basis of the received diagnostic information; and a transmitting section for transmitting the results of the self-diagnosis through the communication device.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image forming apparatus such as a copier which requires relatively frequent maintenance and inspections. 
     2. Description of the Prior Art 
     Image forming apparatus such as copiers and laser printers are precision machines which undergo heavy use daily, so they experience relatively more malfunctions and degraded performance than do other apparatus. Thus they require relatively more frequent maintenance and inspections. Generally, such an apparatus is designed so that, when paper becomes jammed in the apparatus during paper transport, the user can easily remove the jam. However, when a major malfunction occurs, for example, the optical unit requires adjustment due to a shifted leading edge in the copy image, etc., or when other unexplained malfunction occurs, the user cannot handle it and a repairman must be called to correct the problem. When being serviced, the repairman will make various adjustments or load special diagnostic programs into the control unit of the apparatus in order to determine the cause of the malfunction. Generally, this mode in which diagnostic information is loaded in the control unit of the apparatus and the cause of the malfunction is determined is referred to as &#34;the diagnosis mode&#34; or &#34;the simulation mode&#34;. 
     However, when such a prior art apparatus requires servicing, the repairman must go to where the apparatus is located and determine the cause of the malfunction by executing simulations. Further, if parts have to be replaced, he must then return to get the parts and go back to the apparatus location, which is a lot of trouble. 
     SUMMARY OF THE INVENTION 
     The image forming apparatus of this invention, which overcomes the above-discussed and numerous other disadvantages and deficiencies of the prior art, comprises a control unit including a self-diagnostic means; a selection means for setting said control unit to a self-diagnosis mode; and a communication means for, when said self-diagnosis mode is set, connecting said control unit with a communication line, said self-diagnostic means comprising: a receiving section for receiving diagnostic information through said communication means; a diagnostic section for executing self-diagnosis against said apparatus, on the basis of said received diagnostic information; and a transmitting section for transmitting the results of said self-diagnosis through said communication means. 
     The self-diagnostic system for an image forming apparatus of this invention, comprises at least one image forming apparatus; a central controller; and a communication line connecting said central controller with each of said image forming apparatus, said image forming apparatus comprising: a local control unit including a self-diagnostic means; a selection means for setting said control unit to a self-diagnosis mode; and a communication means for, when said self-diagnosis mode is set, connecting said control unit with a communication line, said self-diagnostic means comprising: a receiving section for receiving diagnostic information from said central controller through said communication means; a diagnostic section for executing self-diagnosis against said apparatus, on the basis of said received diagnostic information; and a transmitting section for transmitting the results of said self-diagnosis to said central controller through said communication means. 
     In a preferred embodiment, the central controller comprises: a transmitting means for transmitting said diagnostic information to one of said image forming apparatus through said communication line; a receiving means for receiving said results from said one of said image forming apparatus through said communication line; and a process means for analyzing said transmitted results. 
     In a preferred embodiment, the communication line is a telephone line. 
     Thus, the invention described herein makes possible the objectives of: 
     (1) providing an image forming apparatus from which the cause of the malfunction can be remotely obtained; 
     (2) providing an image forming apparatus which can be subjected to a diagnosis on the basis of information transmitted from a remote place; 
     (3) providing a self-diagnostic system for an image forming apparatus in which the cause of the malfunction of the image forming apparatus can be obtained from a place remote from the place where the image forming apparatus is installed; and 
     (4) providing a self-diagnostic system for an image forming apparatus in which the image forming apparatus can be subjected to a diagnosis on the basis of information transmitted from a place remote from the place where the image forming apparatus is installed. 
     These and further objects of the present invention will become more readily apparent from the understanding of the preferred embodiments, with reference to the drawing figures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     This invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings as follows, wherein like reference numerals represent like parts: 
     FIG. 1 is a block diagram of an image forming apparatus according to the invention. 
     FIG. 2 is a block diagram of a self-diagnostic system according to the invention. 
     FIG. 3 is a flowchart of the diagnosis mode in the image forming apparatus used in the embodiment of FIG. 2. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows diagrammatically an image forming apparatus according to the present invention. The image forming apparatus A shown in FIG. 1 is a copier which comprises a main body 1. In the main body 1, disposed are a control unit 2 which drives and controls a photosensitive drum and an optical system (which are not shown) and controls the paper transport; a communication unit 3 which connects the control unit 2 with a telephone line 9; and a self-diagnostic means 5 for executing the diagnostic mode. The self-diagnostic means 5 is actually realized, in one preferred embodiment, through a program and is executed through a CPU in the control unit 2. The self-diagnostic means 5 comprises a receiving section 7 for receiving diagnostic information over the telephone line 9 via the communication unit 3; a diagnostic section 6 for executing diagnosis based on the diagnostic information, and a transmitting section 8 for sending diagnostic results via the communication unit 3. The control unit 2 previously incorporates a program in it for executing the diagnosis or simulation. When a switch 4 disposed on the main body 1 is turned ON, the control unit 2 is set to the diagnostic mode, and the communication unit 3 is activated. 
     When the copier A malfunctions and requires the attention of a repairman, the user telephones the repairman at a service center and reports to him that the copier A requires service. The user and repairman exchange instructions over the telephone line 9. The repairman then instructs the user to turn ON the switch 4. While still holding on to the line, the user then turns the switch 4 ON so as to cause the communication unit 3 to operate and to set the control unit 2 to the diagnostic mode. When the switch 4 has been turned ON and the diagnostic mode has been set, the self-diagnostic means 5 begins operation and waits for diagnostic instructions from the telephone line 9 via the communication unit 3. When the repairman sends the diagnostic information over the telephone line 9, it is received by the receiving section 7. Then, based on this received information, the diagnostic section 6 performs a diagnosis and produces diagnostic results. The transmitting section 8 then sends the diagnostic results to the repairman over the telephone line 9 via the communication unit 3. The repairman determines if any circuit boards or parts need replacement based on the diagnostic results, and then prepares the necessary parts and takes them to the user. 
     FIG. 2 shows the relationship between the copier A and a central controller B. In FIG. 2, the configuration of the copier A is illustrated in a more specific manner. The copier A is further provided with a telephone 10, and the communication unit 3 comprises a modulator-demodulator (modem) 11 and a duplexer 12. The duplexer 12 is a switch which directs a signal from the telephone line 9 to the demodulator of the modem 11 or to the telephone 10; and a signal from the modulator of the modem 11 or from the telephone 10 to the telephone line 9. The central controller B is located at a service center where the repairman is on standby, and comprises a control unit 22, a communication unit 23 which connects the control unit 22 with the telephone line 9, and a telephone 30. The control unit 22 has a receiving section 27 for receiving diagnostic results from any one of various copiers including the copier A, and a transmitting section 28 for sending diagnostic information to the copier. In the same manner as the copier A, the receiving and transmitting sections 27 and 28 are actually realized through a program and are executed through a CPU in the control unit 22. The communication unit 23 includes a modem 21 and a duplexer 32. 
     With reference to FIG. 3, the operation of the copier A in the diagnosis mode will be described. Hereinafter, the diagnostic information transmitted from the central controller B is referred to as &#34;simulation data&#34;. In a usual state, the switch 4 of the copier A is not operated. The control unit 2 of the copier A continues to perform the main routine (step n2) as long as the switch 4 is off. This main routine controls the normal copier operation. 
     When a malfunction occurs in the copier A and it requires the attention of a repairman, the user contacts a repairman at the service center. The repairman then sets the central controller B so that it can send the simulation data to the copier A. While holding the line, the user then turns the switch 4 ON (step n1) to set the control unit 2 to the simulation mode. When the control unit 2 enters the simulation mode, it operates the duplexer 12 so that the telephone line 9 is connected to the modem 11 (step n3), thereby enabling the transferring of data between the control unit 2 and the controller B. 
     When the copier A becomes capable of receiving simulation data from the controller B, it first sends a busy signal to the controller B (step n4). Reception of this busy signal causes the controller B to send simulation data generated by the control unit 22 to the copier A (step n5). Reception of this simulation data by the copier A causes the control unit 2 to execute the simulation. The control unit 2 in which a program for executing the simulation has been previously incorporated executes the simulation based on the simulation data it receives (step n5). When the simulation is completed, the simulation or diagnostic results are loaded in a transmission buffer (not shown) in the control unit 2 and an END signal is sent to the controller B (step n7), after which the simulation results edited in the transmission buffer are sent to the controller B through the modem 11, the duplexer 12 and the telephone line 9 (step n8). When the simulation results are received at the controller B, an END signal is sent to the copier A (step n9). Reception of the END signal at the copier A causes the duplexer 12 to connect the telephone line 9 to the telephone 10 (step n1O), and the simulation mode in the copier A is completed. 
     When the simulation results from the copier A are received at the controller B, the repairman determines the cause of the malfunction based on the simulation results, and if it is necessary to replace a circuit board or other part, he prepares such and goes to the user. 
     By performing the above operation, the repairman can avoid having to go to the user two times, thus avoiding time and travel expenses. 
     According to the invention, when a user needs a repairman to repair an image forming apparatus, a communication means is used to receive external diagnostic information (i.e., the simulation data in the above-described embodiment), a diagnosis is executed based on the received diagnostic information, and the diagnostic results are sent back over the telephone line, so diagnosis of the image forming apparatus can be performed remotely. Therefore, if a malfunction occurs in an image forming apparatus which requires the replacement of a circuit board or other part, the, need for such replacement can be confirmed Thus, the replacement circuit board or part can be prepared and taken to the malfunctioning image forming apparatus and repair completed in one trip. 
     It is understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be construed as encompassing all the features of patentable novelty that reside in the present invention, including all features that would be treated as equivalents thereof by those skilled in the art to which this invention pertains.