JPS62166375A - Electrophotographic printing device - Google Patents

Abstract

PURPOSE:To make an optical writing head independent of a main printer body and to use the optical writing head and main printer body with independent specifications by making the optical writing head intelligent. CONSTITUTION:The 1st control means 101 which controls the electro-photo graphic processes of the main printer body consists of a printer controller 24. Then, the 1st controls the rotation of a photosensitive body and the processes of an electrostatic charger, a developing device, and a transfer device provided at the periphery of the photosensitive body or the feeding of transfer paper and the operation of a fixing device, etc. The 1st control means 101 sends out print data to the 2nd control means 102, which controls the operation of the optical writing head based on the print data. The optical writing head is equipped with a liquid crystal optical shutter 25 as a light dot generating means, a fluorescent lamp 9 provided as a light source, a lamp heater 10, an LCS panel heater 12, a fan 13 for cooling, etc., and the 2nd control means 102 controls the operation of those respective parts.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electrophotographic printer device that performs dot printing by applying electrophotographic technology.

[Traditional technique]

FIG. 12 shows the configuration of a general electrophotographic printer device.

The electrophotographic printer device A is broadly divided into an interface C, which exchanges information with an external host computer B, an optical writing device D, which performs optical writing using, for example, a liquid crystal optical shutter, and a printer body E, which forms an image by an electrophotographic process. Consisting of

Host computer B sends print data a to interface C, which converts print data a into a video signal (image signal) b and sends it to the printer body along with various status information C. Printer body E
is integrally controlled with the optical writing device, and both exchange video signals d and various status information e, and also send out load control signals in the optical writing device from the printer main body E. As a result, the optical writing device performs optical writing based on the print data a, and the printer body E performs the following:
Printing is done using an electronic process.

[Problems with conventional technology]

However, in the above-mentioned electrophotographic printer device, since the printer body and the optical writing device are integrally controlled, it is difficult to change the specifications of the optical writing device and the printer body independently. It is. Therefore, it is difficult to unify or change specifications among different types of electrophotographic printer devices, and therefore, each model requires a control device with different specifications. Furthermore, since the control of the printer body includes control with an interface, control of an electrophotographic process, control of load within an optical writing device, etc., there is a problem that the control becomes complicated.

[Purpose of the invention]

In view of the above problems, it is an object of the present invention to provide an electrophotographic printer device that can control the optical writing device independently from the printer body by making the optical writing device intelligent.

[Key points of the invention]

In order to achieve the above object, the present invention provides a method for controlling an electrophotographic process in an electrophotographic printer device having an optical writing head that optically writes dots on a photoreceptor to form an electrostatic latent image based on print data. 1 control means;
a second control means for controlling the optical dot generating means provided in the optical writing head, the second control means controlling the optical dot generating means provided in the optical writing head;
It is characterized in that the optical writing head is controlled based on print data sent from the control means.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a control system of an electrophotographic printer according to the present invention.

In FIG. 1, reference numeral 101 denotes a first control means for controlling the electrophotographic process of the printer main body, and is composed of a printer controller 24. As shown in FIG. As will be described later, the first control means controls the rotation of the photoreceptor, the processes of the charging device, the developing device, the transfer device provided around the photoreceptor, the feeding of transfer paper, the operation of the fixing device, etc. control. First control means 1
01 sends print data to the second control means 102, and the second control means 102 controls the operation of the optical writing head based on the print data. The optical writing head includes a liquid crystal optical shutter 25 as a light dot generating means, a fluorescent lamp 9 provided as a light source, a lamp heater 10, an LCS panel heater 12, a cooling fan 13, etc., and the second control means 102 controls each of these parts. control the behavior of

Next, the second control means 102 will be explained in detail.

A clock generator 1 generates a basic clock, and a frequency divider 2 generates a timing clock for the microcontroller 4 and a timing clock for the LC3 drive pattern generator 19. The microcontroller 4 includes 4-bit or 8-bit built-in ROM (read-on memory), RAM (random access memory), and 110 units.
A BIT one-chip microcomputer is preferable.

Furthermore, the microcontroller 4 preferably has a built-in A/D converter 4a for processing analog input signals, and a serial I/F section (hereinafter referred to as SIO) 4b to facilitate serial I/F processing.

Additionally, in order to process the analog output section, it has a built-in DA converter, but instead of this, a microcontroller with a built-in pulse width modulation (PWM) output can configure the DA converter by simply attaching an external integrator. However, it is desirable that external components can be reduced.

The fluorescent lamp 9, which is the light source of the liquid crystal light shutter 25, is driven by DC/AC conversion by the lamp ballast 8. The light output of the fluorescent lamp 9 can be adjusted using the lamp ballast 8.
The input voltage to the microcontroller 4 is controlled by the DC/DC converter 7, and the setting input to the converter 7 is provided by supplying the output of the microcontroller 4 as an analog signal via the DC/AC converter 6.

Therefore, if the input 6a to the DC/AC converter 6 is 8 bits, the output 6b can be set in steps of 1/28, that is, 0.4%.

The output of the photosensor 11 that monitors the light from the fluorescent lamp 9 is fed back to the control unit 7b of the DC/DC converter 7. The control unit 7b compares the output of the photosensor 11 with the set value 6b, and sets the DC/DC based on the comparison result.
By varying the output voltage of the converter 7, the amount of light from the fluorescent lamp 9 is controlled to a predetermined value. Fluorescent lamp 9
The lamp heater 10 for keeping warm has a lamp temperature sensor 16.
The temperature is detected by The microcontroller 4 drives the driver 15b based on this detected value to control the temperature of the lamp heater 10 to a predetermined temperature. L.C.
3 (Liquid Crystal Light Shutter) The panel heater 12 includes one or more elements 12a and 12b.

12c, and drivers 15c and 15d by an LC3 (liquid crystal light shutter) panel temperature sensor 18.

It is controlled by the microcontroller 4 via 15e.

The cooling fan 13 monitors the conditions inside the optical writing device, that is, the ON state of the fluorescent lamp 9, the lamp temperature sensor 16°LCS panel temperature sensor 18. Furthermore, on/off control is performed depending on the state of the ambient temperature sensor 17 and the like.

The outputs of these three temperature sensors are input to the A/D converter 4a of the microcontroller 4. Also, DC/
The light amount monitor output C from the control section 7b of the DC converter 7 is also input to the A/D conversion section 4a and directly monitored by the microcontroller 4.

Note that the lamp temperature sensor 16. LCSCS panel temperature sensor 1 Darkness 2 Both use a thermistor.

Generally, the parameter switch group 14 has a matrix configuration of AnxBm, and in the embodiment shown in FIG.
=5, m=4.

LCS panel heater 1 by parameter switch group 14
2, the temperature of the lamp heater 10, the light intensity of the fluorescent lamp 9, the cooling fan 13, etc., as well as selecting internal parameters to switch the LC3 drive pattern generator 19 corresponding to normal/reversal development method, This is used to set shift conditions for various parameters depending on the difference in writing speed.

The LC3 drive pattern generation unit 19 generates various signals from the drive pattern storage unit 19b (preferably ROM) using the lower address signal 19e and upper address signal L9f from the address counter 19a, and after synchronizing with the latch 19c. , a part of the liquid crystal light shutter drive signal 22 becomes a liquid crystal light shutter control signal 22b by the buffer 19d.

On the other hand, the output from the latch 19c is buffered and sent to the printer controller 20 as a write synchronization signal 20b.
sent to. In synchronization with this, the video I/F 20a is sent to the video signal control section 23, processed into a video signal 22a that matches the optical writing device, and becomes a part of the liquid crystal optical shutter drive signal 22.

The control command information signal 1/F unit 21 includes an external reset request signal 21a and a serial I/F 21b. The external reset request signal 21a is applied to the reset signal generator 5 in the optical writing device, and the reset signal 5a is input to the microcontroller 4 by ORing with the internal reset of the reset signal generator 5.

FIG. 2 shows a main timing chart of the liquid crystal light shutter drive signal 22 mentioned above. The video I/F 20a, which is part of the liquid crystal light shutter drive signal 22, includes the signals shown in FIGS. 2(e) to 2(d).

FIG. 2 (al is a write synchronization signal 20b sent from the latch section 19c of the LSCSC drive-turf generation 9 to the printer controller 24, and FIG. 2 (bl is the LC3
Write signal 22c sent from drive pattern generator 19
As shown in FIG. 2 (C1), the printer main body is delayed by an appropriate time t1 after the rise of the write synchronization signal 20b.
The transfer permission signal 20C is lowered. At the same time, in synchronization with the clock pulse 20d shown in FIG. 2(d), the video signal 20e is sent out during n-pips tz as shown in FIG. 2 (el), and the transfer permission signal 20c is raised. In this embodiment, the timing of this rise is set as a margin for the write signal 22c.
Although the time t3 is earlier than the time t3, the one line writing time T. It is sufficient that the write signal 22C is generated earlier by the time ta (usually several microseconds).

Therefore, the aforementioned time t1. t2+'l can be freely allocated on the printer main body side, which means that there is a high degree of freedom in selecting the clock pulse 20d, and the dependence on the optical writing device is extremely low, which is an advantage that is significantly different from that of a laser printer. I can say it.

FIG. 3 shows an example of the configuration of the video signal control section 23 mentioned above. Hereinafter, the operation of the video signal control section 23 will be explained in a second manner.
This will be explained with reference to the timing chart shown in the figure.

The above-mentioned transfer permission signal 20c is subjected to delay conditioning on the I/F in a D-type FF (flip-flop) circuit 30, and the output of the AND gate 31 is as shown in FIG.
This results in an internal transfer permission signal 23a as shown in FIG. This internal transfer permission signal 23a is supplied to a reset terminal of a clock separator 32 made up of two D-type FF circuits.

The clock separator 32 is shown in FIG.
As shown, internal signals 23b and 23c are output.

In this embodiment, the clock separator 32 is illustrated for the case where the liquid crystal optical shutter 25 operates in two-division driving and the signal electrodes are taken out interdigitally.

In this case, the clock pulse 20d includes the internal transfer permission signal 23a and the internal signal 23b of the clock separator 32.
, 23c, the transfer permission signal 20 is obtained.
In synchronization with c, transfer lock (IB) 22d and transfer lock (IA) 22 are activated as shown in FIG. 2 (1) and ('').
e and these transfer locks 22d.

The video signal 22f is synchronized with the falling edge of the signal 22e.

22g is received by an LC3 driving LSI (not shown).

On the other hand, the upper address signal 19f for the drive pattern storage section 19b shown in FIG. 14, or the upper address signal 19f is directly connected to means such as a setting switch to modify the liquid crystal light shutter control signal 22b.

A specific example of the serial I/F unit 21b shown in FIG. 1 is shown in FIG.

A clock pulse H3CK and serial data H3RXD are output from 5IO4b of the microcontroller 4 to the outside via buffers y40a and 40b, respectively.

On the other hand, serial data H3TXD is sent to 5I04b from the outside.
is input manually via the buffer 41a. Furthermore, an SIO request signal H3REQ is input from the outside to a suitable input port of the microcontroller 4 via a buffer 41b.

FIG. 5 is a timing chart showing the operation of the aforementioned serial I/F section 21b.

FIG. 5(a) shows the SIO request signal input from the outside to the microcontroller 4. After an appropriate time t from the fall of this request signal, the microcontroller 4 sends the SIO request signal to the microcontroller 4 as shown in FIG. 5(d). As shown in FIG. 2, the clock pulse H3CK is outputted to the outside via the buffer 40a. In synchronization with this clock pulse H3CK, serial data H5RXD is output from the microcontroller 4 to the outside as shown in FIG. are exchanged by 8 bits each.Then, the serial clock pulse H5
By generating CK within the optical writing device, independent intelligence that depends on the specifications of the printer itself becomes possible. Note that the present invention is not limited to the timing shown in FIG. 5, and it is of course possible to use, for example, a more -a start-stop synchronization method.

The following table shows the serial data HSTXD and H3RX mentioned above.
An example of the control command information signal of D is shown.

In this embodiment, as shown in the table, the microcontroller 4
As for the serial data H3TXD input to the serial data H3TXD, the 0 bit is always at a low level, the 1 to 3 bits are undefined, and the 4 bits, 7 bits, and 5 bits change the sight of the fluorescent lamp 9 to 4 bits. It was used as a light intensity switching signal to switch in stages, that is, 4 bits were used as 1! , HEX 5 bits
As a PT, light intensity switching is performed in four stages using these 2-bit signals HEXP1 and HEXP2.

In addition, as shown in HPRTAL, the 6-bit printer inputs a low-level signal as an alarm signal to the printer when an abnormality occurs in the printer, and the 7-bit HLAMP inputs a high-level signal when the fluorescent lamp is turned on, and the low-level signal is input as an alarm signal to the printer. was used as a command signal to turn off the fluorescent lamp.

On the other hand, as for the serial data H3RXD input to the microcontroller 4, 0 bit is always set to low level, and 1 bit is set to undefined. Also 2-bit and 3-bit HLDALO.

The 2-bit signal of HLDALI is used as the alarm signal of the LCS panel heater 2, the alarm signal of the lamp heater 10, the alarm signal of the fluorescent lamp 9, and the normal signal of these parts. The 2-bit signal from W and H3ALMI causes the aforementioned LCS panel temperature sensor I8 open signal, lamp temperature sensor 16 open signal, and ambient temperature sensor 17 to be activated.
The open signal of these sensors was taken as the normal signal of these sensors. In addition, the 6-bit HWAIT uses a low level signal as a wait signal for the optical writing head, and the 7-bit HDRDY
The low level signal was used as the ready signal for the optical writing head.

FIG. 6 shows an example of the configuration of the parameter switch group 14 mentioned above.

The parameter switch group 14 has switches connected to the intersections of lines shown as B1 to B4 on the input side and A1 to A5 on the scanning boat side. That is, switches are connected to the intersections of four horizontal lines and five vertical lines to form a switch matrix, and each parameter is set by each individual switch. In this embodiment, the parameter switch group 14 uses the LCS panel temperature, fluorescent lamp temperature and light intensity, cooling system, internal parameters, etc. as parameters.
This is a configuration that is optimally set.

FIG. 7 shows objects to be controlled by each control parameter. In FIG. 7, control parameters are shown in the vertical direction, and controlled objects are shown in the horizontal direction. Moreover, the control target of each control parameter is marked with a circle at the intersection of the control parameter and the control target. For example, if the control parameter is the ambient temperature, the objects to be controlled are the read-ready for optical writing, the LCSCS panel temperature/replacement lamp light amount, and the cooling system control. When the control parameter is the amount of light from the fluorescent lamp, the objects to be controlled are the optical writing head ready, the amount of light from the fluorescent lamp, and the cooling system control. The internal parameters of the control parameters are, for example, when using a thermistor as an ambient temperature sensor, and when using it by ranking it based on the initial variation in resistance value, the control target, for example, the cooling system control, can be changed depending on the rank. It is.

FIG. 8 shows the i-bottom side of the electrophotographic printer device according to the present invention. The electrophotographic process of this electrophotographic printer device is controlled by the printer controller 24 of the first control means 101 as described above.

In FIG. 8, 70 is a drum-shaped photoreceptor, which rotates at a constant speed in the direction shown. After the photoreceptor 70 is charged by a charger 71, optical writing is performed on its photosensitive surface by an optical writing head 72.

The optical writing head 72 includes the above-mentioned liquid crystal light shutter 25, fluorescent lamp 9, LCS panel heater 12, temperature sensors 16 and 17° 18, and further includes the above-mentioned second control means 102, as will be described in detail later. . Further, the optical writing head 72 sends and receives signals to and from the printer controller 24 of the first control means 101 described above.
2 has the liquid crystal light shutter 25 as described above, and by optically selectively opening and closing the individual microshutters constituting the liquid crystal light shutter 25 based on print data, an electrostatic latent image is formed on the photoreceptor 70. Form. This electrostatic latent image is
3, the image is visualized using toner. Transfer paper 74 is stacked at the bottom of the developing device 73, and the uppermost layer of transfer paper 74 is sent out by a paper feed roll 75. The transfer paper 74 is sent out again in synchronization so that the toner image formed on the photoconductor 70 and the leading edge of the transfer paper 74 match with each other by the standby roll 76, and the toner image on the photoconductor 70 is transferred by the transfer device 77. The image is transferred to transfer paper 74. After transfer, transfer paper 74
is separated from the photoreceptor 70 by a separator 78 and transferred to the fixing device 7
9. In the fixing device 79, power supply to the heater 79b is controlled based on the detected value of the thermistor 79a for temperature detection, thereby maintaining the fixing temperature constant. The transfer paper 74 is thermally fixed in a fixing device 79 and then discharged to the outside of the machine by a paper discharge roll 80. On the other hand, untransferred toner remains on the surface of the photoreceptor 70 , but this residual toner is removed by a cleaner 82 after being neutralized by a static eliminator 81 . Furthermore, since charges remain on the surface of the photoconductor 70, after the charges are removed by the eraser 83, the photoconductor 70 is charged again by the charger 71.

FIG. 9 is a sectional view showing the internal structure of the optical writing head 72 mentioned above.

As described above, the optical writing head 72 includes the fluorescent lamp 9 and the lamp heater 10 on its upper surface. Further, a liquid crystal light shutter 25 is disposed below the fluorescent lamp 9, and an imaging lens 84 for forming an image of the light from the liquid crystal light shutter 25 onto the photoreceptor 70 is further provided below the liquid crystal light shutter 25. A lamp temperature sensor 16 is attached to one end of the lamp heater 10, and the aforementioned L is attached to an end of the liquid crystal light shutter 25.
A CS panel temperature sensor 18 is attached to detect the temperature. Further, an ambient temperature sensor 17 is provided approximately at the center of the optical writing head 72, and this also detects temperature in the same manner. The outputs of these temperature sensors are sent to the microcontroller 4, and the microcontroller 4 performs control based on the detected values as described above.

FIG. 10 shows a block diagram when the above-described optical writing head is used to test an electrophotographic printer, test on a production line, or provide service in the field.

The microcontroller 4 receives the control command information signal 1/
The F unit 21 (serial I/F in this embodiment) is connected to the printer main body (external device).

Therefore, since information is exchanged through the serial I/F, completely different things can be executed by changing the information content. That is, another microcontroller 50 is provided in the debanger 5,
This controller 50 also uses a control command information signal I/F section 52.

If these I/F sections 52 and 21 are connected and, for example, the 0 bit of H3TXD and H3RXD shown in the above table is defined as H, it becomes possible to redefine all bits 1 to 7 of each. . Furthermore, if each 0 bit and 1 bit are used for page management, 6 bits from 2 to 7 bits can be independently expanded as 1+3 pages.

If the same microcontrollers 4 and 50 are used, and if a one-chip microcomputer is used, not only will ROM, RAM, Ilo, etc. be built-in, but the microcontroller 50 of the debugger 57 will be a product. Microcontroller 5 of optical writing head 56
Since the same thing as 0 can be used, it has great utility value.

Recent one-chip microcomputers have large RQM sizes and are expensive. Therefore, if a selection input is provided in the parameter switch group 14 or on another input board, this selection input will be read after the program of the microcontroller 4 is started, and the jump selection will be made to the product program or testing program. By doing so, it becomes possible to perform completely different control.

The testing program can be stored as long as the storage capacity of the ROM allows, and in this case the number of selection inputs will increase accordingly.

The microcontroller 50 includes a group of parameter switches 51 . It is also possible to connect a display 53 or a printer 54, thereby allowing the optical writing head 56
Parameters such as LCS panel temperature status and light intensity status can be displayed or printed out, and can be used in a wide range of areas including technology, manufacturing, and services.

For example, when used for technical follow-up, if the parameter switch group 51 is used to set and instruct automatic conversion for each temperature I deg of the liquid crystal optical shutter 25, then the optical writing head 56 is activated, and as shown in FIG. Video signal 1 shown in
A self-printing state is executed through the simulation section of the /F section 20, and the temperature-electro-optical characteristics of the liquid crystal optical shutter are obtained.

FIG. 11 shows an EEP instead of the parameter switch group 14.
An example using a ROM (electrically programmable and erasable PROM) 62 is shown.

In recent years, as typified by IC cards, the write/erase voltage of EEPROM has decreased, and the required voltage has decreased.
It is very easy to use because it occurs internally.

In this embodiment, by using the EEPROM 62, necessary data can be written into the EEPROM 62 in advance. Therefore, the microcontroller 60
ROM 62 and address signal 63. By exchanging data such as a data signal 64 and a control signal 65, the microcontroller 60 performs control operations according to the written data. Further, the optical write head 66 is tested after manufacturing, and parameters are optimized from the outside via the serial I/F 67 into the EEPROM 62.

Furthermore, if you arrange the debugger 57 as necessary,
For example, it is possible to modify the parameters of the optical writing head 66 while monitoring the parameters of the optical writing head 66 during field service on a handy terminal using an LCD display.
It is also possible to carry out the manufacturing at the original manufacturer's manufacturer.

Furthermore, if a microcontroller 67 with a built-in EEPROM 62 is used, the device can be made even more compact, and has great industrial utility value.

〔Effect of the invention〕

As described above, according to the present invention, the optical writing head is made intelligent so as to be independent from the printer body, so that the optical writing head and the printer body can be used with independent specifications. Therefore, by standardizing the video I/F and serial I/F control commands and information signals between the optical writing head and the Blink main body, it is possible to easily standardize and change specifications among electrophotographic printer models. I can do it. In addition, since the printer itself is only controlled by the electrophotographic process,
The conventional problem of complicated control of the printer body can be solved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention.
3 is a circuit diagram showing a specific example of the video I/F control section; FIG. 4 is a circuit diagram showing a specific example of the serial I/F section; Figure 5 is a timing chart showing the operation of the serial I/F section in Figure 4, Figure 6 is an explanatory diagram showing a specific example of a parameter group, Figure 7 is an explanatory diagram showing control parameters and controlled objects, and Figure 8. 9 is a schematic configuration diagram of an electrophotographic printer device according to the present invention, FIG. 9 is a sectional view of an optical writing head according to the present invention, and FIG.
The figure is a block diagram when an optical writing head is used to perform tests inside an electrophotographic printer, tests on a production line, services in the field, etc. Figure 11 is a block diagram showing another example of Figure 10. , 12th
The figure is a schematic block diagram of a conventional electrophotographic printer device. DESCRIPTION OF SYMBOLS 1... Clock generation part, 2... Frequency divider, 4... Microcontroller, 6... D/A conversion part, 7... DC/DC converter, 8... Lamp ballast , 9... Fluorescent lamp, 10... Lamp heater, 11... Photo sensor, 12... LCS panel heater, 13... Cooling fan, 14... Parameter switch group, 16... Lamp temperature sensor, 17... Ambient temperature sensor, 18... LCS panel temperature sensor, 19... LC3 drive pattern generation section, 20... Video signal 1/F section, 21... Control command information signal I/F section, 23...
Video I/F control unit, 24... Printer controller, 70... Photoreceptor, 72... Optical writing head, 101... First control means, 102... Second control means. Patent Applicant Casio Computer Co., Ltd. Same as above Casio Electronics Co., Ltd. Figure 4 Figure 5 Input port Figure 6 Figure 7 Figure 8 Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] In an electrophotographic printer device having an optical writing head that optically writes dots on a photoconductor to form an electrostatic latent image based on print data, a first control means for controlling an electrophotographic process; a second control means for controlling the provided optical dot generation means, the second control means controlling an optical writing head based on print data sent from the first control means. printer device.