JPH0632026A - Apparatus for forming image - Google Patents

Abstract

PURPOSE:To obtain an apparatus for forming images that can be used freely by a plurality of users whenever they want to have access thereto, and prevent the risk of an AC electric source breaker from operating even in the case of using a plurality of image forming apparatuses simultaneously. CONSTITUTION:Data from a host machine 21 is stored in an RAM 19 and, when the present time by a clock 8 comes to be the time set in a clock memory 9 by operation signals from an operation panel 4 or commands from the host machine 21, data in the RAM 19 is read out and then printed out. Besides, a desk device 5 being an external storing device can be replaced by the RAM 19. By permitting electrification to a fixing heater only when the present time comes to be the previously set time, an AC electric source breaker can be prevented from operating even when a plurality of image forming apparatuses are used at the same time.

Description

Detailed Description of the Invention

[0001]

This invention relates to a laser printer, L
The present invention relates to a printer device such as an ED printer and a liquid crystal shutter printer, and an image forming device such as a digital copying machine.

[0002]

2. Description of the Related Art An image forming apparatus such as a laser printer sequentially prints out data transferred from a host apparatus such as an office computer, a personal computer, a word processor.

[0003]

However, if a large file is to be printed out in an environment where the image forming apparatus connected to the network is used, the image forming apparatus will be occupied for a long time. There was a problem that other users could not use it. On the other hand, when a plurality of image forming apparatuses are used, if the timings at which the fixing heaters are turned on happen to overlap with each other, a large amount of current flows, which may cause a breaker of the AC power supply to fall. It was

The present invention has been made in view of the above-mentioned points, and one image forming apparatus can be freely used by each user when he / she wants to use it, and a plurality of image forming apparatuses are used at the same time. The purpose is to prevent the breaker of the AC power supply from dropping even if it does.

[0005]

In order to achieve the above object, the present invention provides a time measuring means which is always operable by a power source independent of the power source of the device body even when the power source of the device body is in a power-off state, and a host device. A memory for storing the data, a time setting means capable of setting an arbitrary time, and a means for reading out the data in the memory and printing it out when the time measured by the time measuring means reaches the time set by the time setting means. It is equipped with. The memory may be an external storage device.

Further, in an image forming apparatus equipped with a fixing heater, a time measuring means capable of always operating even when the power source of the apparatus main body is in a power-off state by a power source independent of the power source of the apparatus main body, and a time at which an arbitrary time can be set. It is preferable to provide a setting means and a means for permitting energization to the fixing heater only when the time measured by the time measuring means reaches the time set by the time setting means. Further, it is desirable to provide a means for displaying the time until the energization of the fixing heater is turned on next.

[0007]

According to the image forming apparatus of the present invention, the data in the memory can be read out and printed out when the time measured by the time measuring means reaches the time set by the time setting means. By setting the time when the user prints out by the time setting means while avoiding the time when the other users print, one image forming apparatus can be used freely when each user wants to use it. If the memory is used as an external storage device such as a hard disk device, a large amount of data can be printed out at once.

According to the image forming apparatus of claim 3 or 4,
Since the energization to the fixing heater is permitted only when the time measured by the time measuring means reaches the time set by the time setting means, the time when the user turns on the energization to the fixing heater by the time setting means is set to another image. Even when using a plurality of image forming apparatuses, it is possible to set by avoiding the time to turn on the power to the fixing heater in the forming apparatus.
Since the timing of turning on the energization of these fixing heaters is deviated, a large amount of current does not flow, and the breaker of the AC power supply does not fall. The waiting time for printing can be easily known by displaying the time until the energization of the fixing heater is turned on next.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram of a laser printer showing an embodiment of the present invention. The laser printer 1 includes a printer controller 2, a printer engine 3, an operation panel (panel device) 4, a disk device 5, a main power source 6, a clock power source (sub power source) 7, a clock 8, and a clock memory 9. ing.

The printer controller 2 is an image processing unit that converts print data from the host machine 21 into video data and outputs the video data to the printer engine 3 in accordance with the control mode set at that time and the control code from the host machine 21. It consists of the following modules. That is, the host interface (hereinafter “interface”)
Is abbreviated as "I / F") 11, engine interface I / F
12, panel interface I / F 13, disk I / F 14,
Each interface of the clock I / F 15, a central processing unit (hereinafter abbreviated as “CPU”) 16, which constitutes a microcomputer, a program ROM 17, a RAM 19, a font ROM 18 and an NVRAM 20 are provided.

The host I / F 11 is an interface circuit for transmitting and receiving various control commands and data to and from the host machine 21, and selects various serial interfaces or parallel interfaces according to the connected host. The engine I / F 12 sends and receives data such as command commands and status information to and from the printer engine 3.

The panel I / F 13 transmits display control data with the operation panel 4 and receives each key information. The disk I / F 14 is an interface for communicating with the disk device 5. Watch I
/ F15 transmits the time information from the clock 8 to the CPU 16.

The CPU 16 is a general-purpose 16- or 32-bit central processing unit, processes data (print data, control code) from the host machine 21 according to a control program stored in the program ROM 17, and the like.
It is responsible for overall control of the printer controller 2. The program ROM 17 stores a control program for controlling data processing in the printer controller 2 and peripheral modules by the CPU 16, and the font ROM 17 stores various fonts used for printing.

The RAM 19 is a random access memory. The RAM 16 is a work memory used when the CPU 16 processes data, a buffer for temporarily storing the data from the host machine 21 by managing it in page units, and temporarily stored in the buffer. It is used as a bit map memory for converting data into an actual print pattern and storing it as video data. The NVRAM 20 is a non-volatile memory that stores and holds internal data even when the power is turned off, and stores the content of the mode instruction from the operation panel 4 and the like.

The host machine 21 is an upper-level device (host device) such as an office computer, a personal computer, a word processor, a data processing device, or an image processing device, and a laser printer for printing the document information created here. The print data and control code corresponding to 1 are transmitted.

The printer engine 3 is composed of a laser writing unit that optically scans an internal photoconductor (not shown) with laser light modulated according to video data, the photoconductor, and process equipment around the photoconductor. An image forming unit, a mechanism section including a sheet conveying section including each roller such as a pair of registration rollers, and an engine driver that is a control section of the mechanism section. The engine driver generates an image by a command and video data from the printer controller 2. Printing is executed by controlling the sequence operation of the forming unit and the sheet conveying unit and the video modulation signal to the laser writing unit.

The operation panel 4 is provided with a display section for displaying various information such as the printer status, and an operation section for setting the printer operation mode and fonts. The disk device 5 includes font data, programs,
The external storage device stores various data such as print data, and is a floppy disk device (FDD) or a hard disk device (HDD).

The main power supply 6 supplies power to each part of the apparatus body. The clock power supply 7 is a battery or an outlet, and power may be supplied to the clock 8 and the clock memory 9 by the battery, or may be branched from the outlet to the main power switch to supply power to the clock 8 and the clock memory 9. You may do it.

The timepiece 8 is always operated by the timepiece power source 7 independent of the main power source 6 even when the main power source 6 is in the power-off state to measure the time, and always outputs information indicating the current correct time. In addition, information is exchanged with the clock memory 9. Therefore, the CPU 16 can obtain the time information at any time via the clock I / F 15 when the time information is desired. Also, the necessary information can be given from the clock 8 side at any time.

Now, from the host machine 21 to the host I / F
The data sent through 11 is print data and control codes (SP, CR, LF, HT,
The print data and the control code are stored in a buffer of the RAM 19.

When the print command or data from the host machine 21 exceeds one page, the CPU 16 issues a print start command to the printer engine 3 through the engine I / F 12. The print data from the host machine 21 is printed via the printer engine 3 in the above-described series of flow.

FIG. 2 is a flow chart showing the operation by the user and the processing according to the first invention by the CPU 16 of FIG. 1 in this embodiment. First, when the user sets the time to start printout using the operation panel 4, the time information is transmitted to the CPU 16 through the panel I / F 13. The CPU 16 makes the transmitted time information into time information that can be discriminated by the timepiece 8, passes it to the timepiece 8 side through the timepiece I / F 15, and stores it in the timepiece memory 9 as the printout time.

On the other hand, data from the host machine 21 is stored in the RAM 19 through the host I / F 11 and converted into video data there. The clock 8 constantly repeats the comparison between the current time and the printout time in the clock memory 9, and when the two match, informs the CPU 16 of that fact,
The CPU 16 transfers the data stored in the RAM 19 to the print engine 3 and prints it out.

FIG. 3 is a flow chart showing the processing according to the second invention by the CPU 16. Host machine 2
When the data is received from 1, it is checked whether or not the time is designated, and if the time is not designated, the normal process, that is, the data from the host machine 21 is read.
After storing it in AM19 and converting it to video data,
The data is transferred to the printer engine 3 and printed out.

If the time is designated, the data from the host machine 21 is written to the disk device 5 which is an external storage device, and the time measured by the clock 8 is designated (the printout time in the clock memory 9). ), The corresponding data is read from the disk device 5, converted into video data, transferred to the print engine 3 and printed out. After that, the data read from the disk device 5 is erased.

FIG. 4 is a block diagram of a laser printer showing another embodiment of the present invention, which comprises a printer controller 31, a printer engine 32, a panel device 33, and a disk device 34. The host device 35 is a host device of this printer. Printer controller 31
Is CPU 36, program ROM 37, font RO
M38, RAM39, NVRAM40, IC card 4
1, timer 46, engine I / F 42, panel I / F
I / F 43, disk I / F 44, host I / F 45
It is composed of F.

The CPU 36 is a central processing unit that controls the printer controller 31 as a whole according to a program from the program ROM 37, a mode instruction from the panel device 33, and a command from the host device 35. The program ROM 37 is a read-only memory that stores the control program of the printer controller 31, and the font ROM 38 is a read-only memory that stores font data.

The RAM 39 is a work memory for the CPU 36, an input buffer for storing input data,
It is a random access memory used for a page buffer for storing page data, a bitmap buffer for storing video data (bitmap data), a font file for storing download fonts, and the like.

The NVRAM 40 is a non-volatile memory for storing the contents of the mode instruction from the panel device 33, and the IC card 41 is a removable memory card used when externally supplying font data and programs. Is. The engine I / F 42 is an interface for communicating commands, status, and print data with the printer engine 32 that actually prints. The panel I / F 43 notifies the user of the current printer status and gives a mode instruction. It is an interface for communicating commands and statuses with the panel device 33 that operates.

The disk I / F 44 is a disk device 34.
It is an interface for communicating with. Host I
The / F 45 is an interface that communicates with the host device 35, and is typically a Centro I / F or RS232C.

The disk device 34 is an external storage device for storing various data such as font data, programs and print data, and is a floppy disk device (FD).
D) and a hard disk device (HDD). The timer 46 is a time measuring means having the same function as a clock, and always operates with a built-in power supply (battery) even when the printer is powered off. The time is changed by operating a key on the panel device 33 or a command from the host device 35.

FIG. 5 is a block diagram showing only a portion related to heater control in the printer engine 32. In this heater control device, 51 is an engine CPU that totally controls the printer engine 32 including a print sequence and heater control. A program ROM 52 stores a control program for the printer engine 32. Reference numeral 53 is a RAM, which is an engine C
It is a work memory used when the PU 51 performs data processing.

Reference numeral 54 denotes a solid state relay (hereinafter abbreviated as "SSR") for turning on / off the power supply to the fixing heater 55 according to an instruction from the engine CPU 51.
Is. 55 is a fixing heater, the power source is AC 100V
Used in. A heat roller 56 is heated by a built-in fixing heater 55 and heats an unfixed toner image on a sheet. 57 is a thermistor, and heat roller 56
The fixing temperature of the surface of the is detected and the corresponding analog signal is output.

In this printer engine, the analog signal corresponding to the fixing temperature output from the thermistor 57 is input to the input port for A / D conversion of the engine CPU 51. The engine CPU 51 converts the input analog signal into a digital signal, compares the fixing temperature indicated by the digital signal with a preset target temperature, and if the fixing temperature is higher than the target temperature, turns off the SSR 54. When the fixing temperature is lower than the target temperature, the SSR 54 is turned on and the fixing heater 55 is turned on.

If two printers are used and printing is executed at the same time and ends at the same time, the timings at which the fixing heater is turned on are overlapped as shown in FIG. As a result, a large amount of current may flow, and the maximum value of the consumed current of the heater may be doubled. In that case, the breaker of the AC power supply may fall.

Therefore, in the two printers according to this embodiment, the times at which the energization to the fixing heater is turned on are set so as not to overlap. Therefore, even if the printing is started at the same time, the timing at which the energization to the fixing heater is turned on is deviated as shown in FIG. 6, and the maximum value of the current consumption of the heater is not doubled. Note that FIG.
The printer 2 will take some printing time, but when the first sheet of paper is going to be printed, the fixing temperature on the surface of the heat roller is not sufficient, and even if the power to the fixing heater is immediately turned on, At that time, the power-on time to the fixing heater of the printer 1 coincides with the power-on time, and the power-on time to the fixing heater of the printer 2 does not arrive until the power is on.

FIG. 7 shows a case where four printers are used. Since it is necessary to set a long interval for turning on the power to the fixing heater, the printing speed becomes slower. This is because the printing operation for each sheet is not executed until the fixing temperature on the surface of the heat roller reaches the target temperature.

FIGS. 8 and 9 are flowcharts showing an example of the heater energization time setting process by the CPU 36 shown in FIG. 4 in this embodiment, and will be described assuming two printers. Each of these routines starts when the heater energization time is input by the key operation of the panel device 33 of each printer, first sets the heater energization (on) time Ton, and then sets the heater energization interval Tint, and the NVRAM 40. Remember.

FIG. 10 is a flow chart showing the heater energization time updating process by the CPU 36. This routine starts every 0.5 seconds, first determines whether the current time by the timer 46 has reached the first heater energization time Ton, and if it does not reach the first heater energization time Ton, terminates the processing. At the first heater energization time Ton, after adding the heater energization interval Tint to the time Ton, it is set as the next heater energization time Ton.
The Hon flag of the RAM 39 is set to "1", and the process ends.

FIG. 11 is a flow chart showing heater control by the engine CPU 51 of FIG. This routine also starts every 0.5 seconds, and it is first checked whether or not the fixing temperature on the surface of the heat roller 56 is higher than the target temperature (reference). If the fixing temperature is higher than the target temperature,
It is checked whether or not the energization to the fixing heater 55 is turned on, and if it is turned off, if it is turned on, the SSR 54 is turned off to turn off the energization to the fixing heater 56. To finish.

On the other hand, if the fixing temperature is not higher than the target temperature, it is checked whether or not the energization to the fixing heater 55 is turned on. If it is turned on, the processing is terminated and turned off. RAM 3 of the printer controller 31
The Hon flag is read from 9 and its state is checked. If it is reset to "0", the processing is ended.

When the Hon flag is set to "1", that state means that the energization of the fixing heater 55 is permitted. Therefore, after the Hon flag is reset to "0", the fixing heater is reset. The power supply to 55 is turned on, and the process ends. As described above, since the heater energization time set in each printer is different, the energization on time to the fixing heater in each printer is not shifted, and the maximum value of the current consumption of the heater is not doubled. There is no risk of the breaker falling off.

As shown in FIG. 7, when the number of printers used increases, the print speed decreases and the print waiting time increases. The user does not know why the printing is slow, and is expected to be in trouble. Therefore, the print waiting time may be displayed on the display device of the panel device 33. The print waiting time is estimated by the following equation. Print wait time = next heater energization time-current time

The embodiment in which the present invention is applied to a laser printer has been described above. However, the present invention is not limited to this, and other printer devices such as an LED printer and a liquid crystal shutter printer, as well as various kinds of digital copying machines and the like. Can be applied to the image forming apparatus.

[0045]

As described above, the first and second
According to this invention, one image forming apparatus can be freely used when each user wants to use it. Further, according to the third and fourth aspects, even when a plurality of image forming apparatuses are used at the same time, there is no fear that the breaker of the AC power supply will fall.

[Brief description of drawings]

FIG. 1 is a block diagram of a laser printer showing an embodiment of the present invention.

2 is a diagram illustrating an operation performed by a user in the embodiment of FIG. 1 and FIG.
It is a flowchart which shows the process by CPU15 of.

FIG. 3 is a flowchart showing another processing by the CPU 15 of FIG.

FIG. 4 is a block diagram of a laser printer showing another embodiment of the present invention.

5 is a block diagram showing only a portion related to heater control in the printer engine 32 of FIG.

FIG. 6 is a timing chart for explaining the operation of the embodiment of FIG.

FIG. 7 is another timing diagram of the same.

FIG. 8 is a flowchart showing an example of heater energization time setting processing by the CPU of FIG.

FIG. 9 is a flowchart showing another example of the heater energization time setting process.

FIG. 10 is a flow chart showing a heater energization time updating process.

11 is a flowchart showing heater control by a heater CPU 51 shown in FIG.

FIG. 12 is a timing chart for explaining a problem of heater control in a conventional printer.

[Explanation of symbols]

1 Laser Printer 2,31 Printer Controller 3,32 Printer Engine 4,33 Operation Panel (Panel Device) 5,34 Disk Device 6 Main Power Supply 7 Clock Power Supply 8 Clock 9 Clock Memory 16,36 Central Processing Unit (CPU) 17,37 , 52 Program ROM 18, 38 Font ROM 19, 39, 53 RAM 20, 40 N
VRAM 21 Host machine 46 Timer 51 Engine CPU 54 Solid state relay 55 Fixing heater 56 Heat roller 57 Thermistor

Claims (4)

[Claims] 1. A time measuring means capable of always operating by a power source independent of the power source of the device body even when the power source of the device body is in a power-off state, a memory for storing data from a host device, and an arbitrary time can be set. An image forming apparatus comprising: a time setting unit; and a unit for reading out the data in the memory and printing it out when the time measured by the time measuring unit reaches the time set by the time setting unit. . 2. The image forming apparatus according to claim 1, wherein the memory is an external storage device. 3. In an image forming apparatus having a fixing heater, a time measuring means that can always operate even when the power source of the apparatus main body is in a power-off state by a power source independent of the power source of the apparatus main body, and an arbitrary time can be set. An image forming apparatus comprising: a time setting means; and a means for permitting energization to the fixing heater only when the time measured by the time measuring means reaches the time set by the time setting means. 4. The image forming apparatus according to claim 3,
Next, the image forming apparatus is provided with means for displaying the time until the energization of the fixing heater is turned on.