JPH0569590A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To properly replace an array line head to obtain a sharp and high- quality image by a method wherein when an actual light-emitting drive number of an electronic light-emitting element in the array line head exceeds a reference light-emitting drive number, an array line head life management message is indicated. CONSTITUTION:An electrophotographic device draws a latent image on a photosensitive drum, not shown in the figure, by using an array line head 20 provided with a large number of electronic light-emitting elements 21. In this case, based on a reference signal generated by a means 22 and a printing data signal outputted from a circuit 25, a light-emitting drive number of the electronic light-emitting element 21 is counted by a counter 40A. In addition, a reference light-emitting drive number up to the end of the life of the electronic light- emitting element 21 is set by a keyboard 35 of a control part 30. The aforesaid drive numbers are compared with each other. If the light-emitting drive number exceeds the reference light-emitting drive number, a life managing signal is generated in a ROM 32 and a CPU 31. In accordance with the life managing signal, a message for managing the life of the array line head 20 is indicated on a display 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus for drawing a latent image on a photosensitive drum using an array line head.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional electrophotographic apparatus. In the figure, in the main body 1, the image forming section 10 and the heat fixing device 19 are provided.
(Heat roller 19A, press roller 19B) are built in. 2 is a paper cassette, 3 is a pickup roller, 4 and 5 are paper guides, and 6 is a paper discharge tray.

The image forming section 10 includes a photosensitive drum 11, a charging device 12 arranged around the photosensitive drum 11, an array line head 20, a developing device 13 including a developing roller 14, a waste toner collecting box 16 including a blade, a charge removing unit. It consists of a lamp 17 and the like. A transfer device 15 forms a part of the image forming unit 10. Reference numeral 18 denotes a discharger for removing the electric potential remaining on the paper even after the toner image is transferred.

Here, the array line head 20 is formed by arranging a large number of electroluminescent elements, which emit light from the end face when the potential difference between the pair of electrodes exceeds a predetermined threshold value, in a line, and outputs the print data signal. A corresponding latent image is drawn while the corresponding electroluminescent element is driven to emit light.

In such an electrophotographic apparatus, when a latent image is drawn on the photosensitive drum 11 charged to a predetermined potential by the charger 12 using the array line head 20, the latent image is formed as the photosensitive drum 11 rotates. The developing device 13 develops a toner image, and the transfer device 15 transfers the toner image onto a charged sheet. Further, the transferred toner image is reliably fixed on the paper while passing through the thermal fixing device 19.

By the way, since the performance of the photosensitive drum 11 deteriorates as the number of times of use increases, it is supposed that the photosensitive drum 11 should be replaced when it is no longer able to form a clear image because it has reached the end of its life. Therefore, the collection capacity of the waste toner box 16 is formed so as to be full when the photosensitive drum 11 reaches the end of its life, and for this reason, the image forming unit 1 including the photosensitive drum 11, the waste toner box 16 and the like.
It is often said that 0 is exchanged as a whole.

[0007]

By the way, nowadays, the array line head 20 emits light with a high frequency of light, under the present circumstances where diversification, high density and high image quality are strongly demanded. In particular, the frequency of light emission driving of the electroluminescent element arranged in a certain specific region becomes extremely high. However, since the life of the electrophotographic apparatus is managed as a representative of the life of the photosensitive drum 11, independent life management of the array line head 20 and the like is not performed. Therefore, the array line head 2 that may not be proportionally synchronized with the life of the photosensitive drum 11
If some of the electroluminescent elements of No. 0 are deteriorated, there is a problem that a blur or the like is generated in a part of the image during driving.

An object of the present invention is to provide an electrophotographic apparatus capable of independently forming the life of the array line head and always forming a clear image.

[0009]

SUMMARY OF THE INVENTION The present invention uses an array line head in which a large number of electroluminescent elements that emit light from an end face when a potential difference between both electrodes exceeds a predetermined threshold value are arranged in rows. In an electrophotographic apparatus formed so as to draw a latent image on a drum, a light emission drive number counting means for directly or indirectly counting the number of times the electroluminescent element is driven to emit light, a reference light emission drive number setting means, Life management signal generating means for comparing the set reference light emission drive count with the counted light emission drive count and outputting a life management signal when the count light emission drive count is equal to or greater than the reference light emission drive count; Notification means for receiving a lifespan management signal and fornouncing the lifespan management message of the array line head.

[0010]

According to the present invention having the above-described structure, the light emission driving frequency counting means is configured to emit light from the electroluminescent element based on the actual light emission frequency of one or more specific electroluminescent elements of the array headline, the rotational speed of the photosensitive drum, or the number of print sheets. The number of times of driving is formed so that it can be counted directly or indirectly. At the start of operation, the reference number of times of light emission drive is set to the reference number of times selected and determined based on empirical rules and the like to start the operation. Then, the lifespan management signal generating means outputs the lifespan management signal when the count light emission drive count is equal to or greater than the set reference light emission drive count while continuously or intermittently comparing both light emission drive counts. As a result, the notifying means notifies the operator of the approaching or exhaustion of the life of the array line head by displaying or sounding. Therefore, since it is possible to take measures such as timely replacement of the array line head without waste, it is possible to always form a clear image.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, this electrophotographic apparatus includes a main body 1 similar to the conventional example (FIG. 4) having a built-in engine 50 such as a photosensitive drum 11, a developing device 13, a thermal fixing device 19, and a control unit 30. In addition, it is provided with a light emission driving frequency counting means, a reference light emission driving frequency setting means, a life management signal generating means, and a notification means so that the fact can be notified when the life of the array line head 20 approaches or expires. Has been done.

First, the control unit 30 drives and controls the entire apparatus, and includes a CPU 31, a ROM 32, a RAM 33,
It comprises a display 34, a keyboard 35, a clock circuit 36, an input port 37, an input / output port 38 and the like. I / O port 3
The engine 50 is connected to 8.

Next, a drive circuit for the array line head 20 will be described. A reference signal Ss whose polarity changes in a predetermined cycle as shown in FIG. 2A is applied to one electrode 21A of each electroluminescent element 21 shown in FIG. The print data signal Sd of FIG. 2B output from the cycle control circuit 25 is input. The print data signal Sd is obtained by subjecting the original print data signal Spd from the print data signal generating means 24 to phase control with the phase control signal Sph. That is, the print data signal Sd has the same phase as the reference signal Ss.

Therefore, when the potential difference [(Ss)-(Sd)] between the two electrodes 21A and 21B exceeds a predetermined threshold value (+ Vth, -Vth), the electroluminescent element 21 emits light and the photosensitive drum. A latent image can be drawn on 11 charged predetermined portions.

Here, the light emission drive number counting means is formed of a counter 40 to which the reference signal Ss and the print data signal Sd are input, and the electroluminescent element 21 specified in advance.
However, in this embodiment, the number of times Ni that is driven to emit light is directly counted.

Therefore, the print data signal Sd from the synchronous control circuit 25 has a potential difference [(Ss)-(Sd)] between both electrodes in FIG. 2 in relation to the reference signal Ss having a constant absolute value.
A threshold value (+) at which light can be emitted as indicated by hatching in (C)
Vth, -Vth) is connected to the counter 40 via a comparator 26 for making a comparison judgment as to whether or not the value exceeds Vth, -Vth).

Next, the reference light emission driving frequency setting means is means for setting the reference light emission driving frequency Ns until the specified electroluminescent element 21 approaches the end of its life or expires.
In this embodiment, the set light emission drive count Ns, which is formed from the keyboard 35 and is set, is stored in the RAM 33.

The life control signal generating means is composed of a ROM 32 storing the program (ST14) of FIG. 3 and a CPU 31 for executing the program, and counts light emission actually counted by comparing both times Ns and Ni. When the drive count Ni is equal to or greater than the set reference emission drive count Ns, the life management signal is output. Receiving the life management signal, the notification means for notifying the operator of the life management message of the array line head 20 (for example, "Please replace the array line head") is also used as the display 34. ing.

In the above, the drive circuit of the array line head 20 is provided with the independent reference signal generating means 2 as shown in FIG.
2, the phase control signal generating means 23, the print data signal generating means 24, and the synchronization control circuit 25, and the light emission drive frequency counting means is constituted by the counter 40. These means 22, 23, 24, 25 are controlled. It can be constructed and implemented by using the CPU 31, the ROM 32, the RAM 33, the clock circuit 36, and the functions of these constituting the unit 30. Similarly, the counter 40 may be constructed from the CPU 31, the ROM 32, and the count memory. In this case, the count memory should be made non-volatile by the EEPROM 39 or the like shown by the two-dot chain line in FIG.

Next, the operation of this embodiment will be described. Using the keyboard 35 as the reference light emission drive frequency setting means, the number of light emission of the specific electroluminescent element 21 which may require replacement of the array line head 20 is set as the reference light emission drive frequency Ns.

Here, when the printing operation is started, the counter 40 as the light emission drive frequency counting means counts the actual light emission drive frequency Ni.

Then, C as a life management signal generating means
The PU 31 compares the actual light emission drive count Ni with the reference light emission drive count Ns (ST14 in FIG. 3), and outputs a life management signal when Ni ≧ Ns. In other words, the display 34 as the notification means is notified of the life management message (S
T15). This management operation is performed every time printing of one page is started (ST10), and printing is completed (ST16).
Can continue until.

It should be noted that the light emission drive frequency counting means is the CPU 31, the ROM 32, and the EE which have been described as the modified examples.
When the PROM 39 is constructed, ST11 of FIG.
It may be formed so as to execute the steps 1 to 13. That is, it is determined from the reference signal Ss and the print data signal Sd whether or not the CPU 31 emits light, and the light emission drive count Ni is set to EE.
It suffices to write the data in the PROM 39 step by step.

According to this embodiment, however, the light emission drive frequency counting means [40, (31, 32, 39)], the reference light emission drive frequency setting means (35), and the life control signal generating means (31, 32). ) And a notification means (34) are provided to automatically notify the lifespan management message when the array line head 20 approaches the end of its life or runs out. Therefore, the array line head 20 is replaced in a timely manner. Therefore, clear image printing can always be performed.

Also, the light emission drive frequency counting means (40)
Is a drive circuit (22 to 25) for the array line head 20.
Therefore, since the actual light emission driving frequency Ni is directly counted, the life can be more accurately managed.

Further, since the lifespan management signal generating means is constructed so that the CPU 31 and the ROM 32 of the control unit 30 are shared, a reliable high speed check can be performed.

In the above embodiments, the fact that a specific electroluminescent element 21 is driven to emit light is directly counted. However, a photosensitive drum on which a latent image is drawn by using this array line head 20. It is also possible to form it by indirectly counting the number of rotations of 11 or the number of printed sheets. In this case, the value Ns set in the light emission drive number setting means (35) is different from that in the above embodiment.

[0028]

According to the present invention, an electrophotographic apparatus using an array line head is provided with a light emission drive frequency counting means, a reference light emission drive frequency setting means, a life control signal generating means and a notification means, and an array line is provided. Since the number of actual light emission driving times of the electroluminescent elements of the head is directly or indirectly counted and a notification is given when the preset reference number of light emission driving times is exceeded, it is possible to appropriately replace the array line head. You can always print with clear and high image quality.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the light emitting operation of the electroluminescent element.

FIG. 3 is likewise a flowchart for explaining the operation.

FIG. 4 is a diagram for explaining a schematic configuration of a main body of the present invention and a conventional example.

[Explanation of symbols]

 1 Main Body 2 Paper Cassette 10 Image Forming Section 11 Photosensitive Drum 12 Charging Device 13 Developing Device 15 Transfer Device 16 Waste Toner Box 17 Electrification Lamp 19 Thermal Fixing Device 20 Array Line Head 21 Electroluminescence Device 21A One Electrode 21B Other Electrode 22 Reference Signal Generation Means 23 Phase control signal generating means 24 Print data signal generating means 25 Synchronous control circuit 26 Comparator 30 Control section 31 CPU (life management signal generating means) 32 ROM (life management signal generating means) 33 RAM 34 Display (notification) 35) Keyboard (reference light emission drive frequency setting means) 36 Clock circuit 39 EEPROM (light emission drive frequency counting means) 40 Counter (light emission drive frequency counting means) Ns Reference light emission drive frequency Ni count Light emission drive frequency

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G03G 15/00 103 8004-2H 15/04 116 9122-2H

Claims (1)

[Claims] 1. A latent image is drawn on a photosensitive drum by using an array line head in which a large number of electroluminescent elements which emit light from an end surface are arranged in a row when a potential difference between both electrodes exceeds a predetermined threshold value. In the electrophotographic apparatus formed in, a light emission drive number counting means for directly or indirectly counting the number of times the electroluminescent element is driven to emit light, a reference light emission drive frequency setting means, and a set reference light emission drive frequency. Life count management signal generating means for outputting a life management signal when the count light emission driving count is compared with the reference count light emission driving count and comparing the counted count light emission driving count, An electrophotographic apparatus comprising: a notification means for notifying a lifespan management message of an array line head.