JPH079732A - Printing device - Google Patents

Abstract

PURPOSE:To prevent a wasteful power consumption by a method wherein a means for controlling the power supply timing to respective driving systems related to a series of printing processes on the basis of the distribution of dots of detected image and the like are provided. CONSTITUTION:When one paginal printing data are stored, an inputting and expansion control section 103 reads printing data in regular order out of a page memory 102 and, at the same time, analyzes them so as to form bit map data with reference to a font ROM 104 and the like. The formed bit mat data are expanded and stored. The power source control section of a printing I/F section is a section for ON-OFF controlling the power source of the printing I/F section, which is indicated by surrounding with dotted line, and is normally turned OFF for economizing in electric power when no printing is performed. Accordingly, even under the stand-by condition of printing data sending from an external device, the power source of the printing I/F section is turned OFF. When ready signal 122 is OFF, the power source of the printing I/F section is kept to be OFF. When the signal 122 is ON, the inputting and expansion control section 103 turns signal 123 ON.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus and a printing apparatus for recording a visible image on a recording medium.

[0002]

2. Description of the Related Art The heat fixing method is a method in which a toner transferred onto a recording medium such as a recording paper is thermally fused to the recording medium. It is used in printing apparatuses that use electrophotography, such as laser beam printers and LED printers that are becoming widespread.

Normally, when the power of this type of device is turned on, the temperature of the fixing device (strictly speaking, the roller for fixing) is kept to a certain level or higher in order to allow the fixing process to be normally performed at a minimum. It waits and is controlled to maintain that temperature.

[0004]

However, once the fixing device is powered on, this fixing device always consumes power for keeping the temperature constant. That is,
Power is consumed regardless of whether the printing process is performed, in other words, whether the device is used.
In particular, since the heater of the fixing device consumes a large amount of power, improvement in this respect has been desired.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and controls the timing of power supply to each drive system involved in the printing process depending on the image to be printed. An object of the present invention is to provide a printing apparatus that can reduce wasteful power consumption.

In order to solve this problem, the printing apparatus of the present invention has the following configuration. That is, in a printing device that prints an image on a predetermined recording medium, a detection unit that detects the dot distribution of the image to be printed,
A control unit that controls the timing of power supply to each drive system related to a series of printing processes based on the detected dot distribution.

[0007]

In the structure of the present invention, the power supply timing to each drive system provided in the conveyance path of the recording medium is controlled based on the dot distribution of the image to be printed.

[0008]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the embodiment, an example applied to a laser beam printer will be described, but the present invention is not limited to this as will be apparent from the following description.

The laser beam printer in the embodiment is
It consists of a printer controller that receives print data, develops bitmap data based on the print data, and outputs it as a video signal, and a printer engine that receives the video signal and actually forms an image. .

FIG. 1 is a block diagram of the printer controller of the printing apparatus according to the embodiment.

In the figure, 101 is an input I / F unit for receiving print data from a host computer or the like, and 1
Reference numeral 02 is a page memory that temporarily stores the received print data, 103 is an input expansion control unit that generates bitmap data based on the character code and drawing command included in the input print data, and 104 stores a character pattern. Font ROM, 105 is an input / expansion control unit 103
Bit map memory for expanding the bit map data generated by, 106 is a print I / F unit power supply control unit, 1
07 is a print I / F control unit, 108 is a scan buffer,
A parallel-serial converter 111 converts parallel data into serial data.

FIG. 2 shows the mechanism of the printer engine section of this printing apparatus, and FIG. 6 shows a block diagram of the control system of the printer engine section.

FIG. 201 is a semiconductor laser,
202 is a polygon motor, 203 is a rotary polygon mirror, 204
Is a photosensitive drum, 205 is a light receiving element for generating a known beam detect signal, and 206 is a fixing device. 213 is a transfer device and 214 is a developing device. A fixing device heater is provided near the fixing device 206.

FIG. 6 shows a block configuration example of the electronic control system of the printer engine section.

In the figure, a printer engine control unit 601 exchanges signals with a printer controller, and controls each component described below.

Reference numeral 602 denotes a heater power switch for switching driving / non-driving (power on / off) of the heater of the fixing device 206, and 603 driving / non-driving (power on / off) of various motors such as the fixing device motor 127. 604 is a jam sensor that detects a paper jam in the recording paper conveyance path, 605 is a paper sensor that determines whether there is a recording paper in the paper feed cassette, and 606 is a paper sensor.
Is a toner sensor that detects whether the amount of toner remaining in the developing device 214 has decreased. Reference numeral 608 denotes a drive unit including a motor for driving the cucumber roller 210,
Reference numeral 9 denotes a semiconductor laser element 20 based on the serial data video signal transferred from the printer controller unit.
1 is a laser driver for driving 1.

Next, the operation of the embodiment will be described with reference to FIGS. 1, 2 and 6.

The print data 121 sent from a host device (not shown) such as a host computer is stored in the page memory 102 page by page via the input I / F unit 101.

When the print data for one page is stored, the input / expansion control unit 103 sequentially reads the print data from the page memory 102, analyzes the print data, and refers to the font ROM 105 or the like to generate bitmap data. To do. Then, the generated bitmap data is expanded and stored in the bitmap memory 105. The bitmap memory 105 is a memory having a capacity capable of storing dot data for at least one page, and dot data to be printed is expanded as shown in FIG. The bitmap memory 105 has a 1-dot information area 301 at the end of each line for each line data. Therefore, in practice, each line of the printing area has an extra memory amount of 1 bit.

This information area (hereinafter referred to as dot presence / absence information) 3
For 01, the information of "1" is entered up to the line where the dot data of the page is "1", and when the dot data "1" is lost thereafter, the information of "0" is entered.

Reference numeral 106 'in FIG. 3 shows an enlarged state of the reference numeral 106 portion in the bitmap area 105 shown in FIG. In the figure, the bit that is "1" in the bitmap data area indicates that the dot is printed, and conversely, the portion where nothing is written indicates that the bit is not printed.

Further, as indicated by reference numeral 106 'in the drawing,
“1” is stored in the dot presence / absence information 301 of lines up to the reference numeral 302, indicating that there is a dot data “1”. Since the line 303 and the following lines have no dot data “1”, “0” is stored. Has been done.

The input / expansion control unit 103 expands the dot data in the bitmap memory 105 and also writes the dot presence / absence information 301 in the bitmap memory 105. That is, by looking at the dot presence / absence information 301, it is possible to know up to which line the black data of the page exists. When the dot data for one page is completely expanded in the bitmap memory 105, the input / expansion controller 103
First inspects a READY signal 122 sent from a print controller (not shown).

Ready No. 122 is a signal sent from the printer engine control unit 601 of the printer engine unit.
This is a status signal indicating whether the printer engine unit is in a ready state. For example, the printer engine control unit 60
1 receives the signal indicating that there is no abnormality from the jam sensor 604, the paper sensor, the toner sensor, or the like, and outputs the ready signal described above.

The print I / F section power supply control section 106 is a section for controlling ON / OFF of the power supply of the print I / F section surrounded by a dotted line in FIG. 1, but normally, in order to save electricity when not printing. Turned off. Therefore, the power supply of the print IF unit is turned off even in the standby state for receiving the print data from the external device.

Ready signal 122 is faulted (OFF)
In the case of, at least the power supply of the print I / F unit remains off. When the signal 122 is true (ON), that is, when the printer engine unit is in the ready state, the input expansion control unit 10
3 sets the print I / F unit power supply control signal 123 to true.

The print I / F power supply control unit 106 sends a signal 12
If 3 is true and there is unoutput data,
The power of the printing I / F section surrounded by the dotted line in FIG. 1 is turned on.
The input expansion control unit 103 also sends a print start signal 124 to the control unit on the printer engine side.

Upon receiving the signal 124, the printer engine control unit 601 turns on the polygon motor 202 to rotate the rotary polygon mirror 203, and at the same time, the drum motor 209.
Is turned on and the photosensitive drum 204 is rotated. The photosensitive drum 204 is provided with a disc 211 having a coaxial hole, and the paper 207 fed by the paper feed roller 210 in response to a signal when the hole of the disc 211 passes through the photocoupler 212. Is synchronized with the dot data recorded on the photosensitive drum 204 in the vertical direction. Further, the light receiving element 205 receives a horizontal synchronizing signal (generally known as a beam detect signal BD).

After the power of the print I / F is turned on, the print I / F is
The F control unit 107 sequentially reads the dot data from the bitmap memory 107, sends the dot data to the scan buffer 108 in synchronization with the vertical synchronization signal 125 and the horizontal synchronization signal 126. The scan buffer 108 has two buffers RA
It consists of M109 and 110. It has a so-called double buffer format, and while the dot data from the bitmap memory 105 is being written in one of the RAMs 109 and 110, the other is read and sent to the printer engine side, which enables high-speed printing. It is something that aims to change.

The data 108 read from the scanner buffer 108 is further converted into serial data by the parallel-serial converter 111, and then sent as a video signal 129 to the laser driver 609 on the printer engine side.
The laser driver 609 drives the semiconductor laser 201 based on the received video signal to turn on / off the laser light.
Control.

The laser emitted from the semiconductor laser 201 is
Scanning exposure is performed on the photosensitive drum 204, and as a result, an electrostatic latent image is formed on the photosensitive drum 204. Photosensitive drum 2
Since 04 rotates at a constant speed in the direction of the arrow in the figure, a two-dimensional electrostatic latent image is formed. Then, the electrostatic latent image reaches the developing device 205, and a developing process is performed to attach the toner to the laser-exposed portion (existence portion). Further, the transfer device 213 transfers the toner image onto recording paper. Then, the recording paper to which the toner is attached is thermocompression-bonded by the fixing roller 206 and is discharged to the outside.

When transferring data from the bitmap memory 105 to the scan buffer 108, the print I / F control unit 107 looks at the last bit state (dot presence / absence information 301) of the data of one line, and The signals 127 and 128 are operated as shown in the timing chart of FIG.

That is, in FIG. 4, when the data presence / absence information (bit information of the information area 301) becomes H level (indicating that there is data), the fuser motor ON signal 127 is set to true after T1 time, and T6 time is reached. After that, the fuser heater ON signal 128 is set to true. This can be realized by, for example, preparing a counter and counting clocks (not shown) corresponding to the respective times, so the details thereof will not be described.

The T1 time means the print I / F control unit 10.
7 is the time from when the dot data is sent from the dot data to the printer engine through the scan buffer 108 until the position of the paper 207 on which the toner image of the dot data is transferred reaches the entrance of the fixing roller 206.

Further, T6 is a value obtained by subtracting the time required for the fixing device heater to be turned on and the fixing device to reach the fixing possible temperature from the time T1.

T4 and T5 are the first page and the second page, respectively.
Indicates the length of the part of the page data. T2 is paper 2
07 is a time that passes through the fixing roller 206 and is constant. On the other hand, T4 + α and T5 + α are the data length T4,
It is T5 plus the rise time α of the fuser heater, which varies depending on the length of the data.

T3 is an interval until the data of the first page and the data of the second page are output, and varies depending on the time for developing the text data in the bitmap memory 105.

By performing the above control, the heater of the fixing device can be turned on only when necessary, and the power consumption can be reduced.

When the printing I / F control unit 107 completes sending the data of the page of interest, it sends an end signal 130 to the input expansion control unit 103.

In FIG. 4, if the data ends in two pages, the signal 130 rises at the timing shown in FIG. This signal 130 is issued when it is determined that the data next to the currently output data is not in the page memory and a predetermined time has elapsed.

The input / expansion control unit 103 looks at the page memory 102, and if there is no unoutputted data to be printed next, sets the signal 123 as a fault to print I / O.
Turn off the power to the F section.

The specific operation processing contents of the above embodiment are shown in FIG.
This will be described with reference to the flowchart of FIG.

First, the operation processing of the input expansion control unit 103 of the printer controller will be described with reference to the flowchart of FIG. The program based on this flowchart is stored in a ROM provided in a CPU (not shown) in the input / expansion control unit 103. Further, when print data is supplied to the input I / F unit 101 from the host device, an interrupt signal is generated in the CPU in the input / expansion control unit and is supplied to the input I / F unit in the interrupt processing routine. It is assumed that the process of storing data in the page memory 102 is performed.

When the power of the apparatus is turned on, first, in step S1, the initialization processing of the entire apparatus is performed. at this point,
The power of the print I / F unit is turned off. After that, the host device is notified of a signal that can be received via the input I / F unit 101. As a result, data acquisition by the above-described interrupt processing can be performed.

Next, in step S5, it is determined whether print data is loaded in the page memory 102, and the process waits until print data is loaded.

When print data reception is detected, step S
In step 7, the bitmap data based on the received print data is generated and written in the bitmap memory 102. At this time, for example, when one character pattern is written in the surprise map memory 105, the dot presence / absence information of the previous line including the most significant line where the dot of the written data is “1” is “ Write 1 ".

When the writing of the bitmap data for one unit is completed, the process proceeds to step S9 to judge whether the expansion of the bitmap data of one page sentence is completed (it can be judged by the page break command), and it is not completed. If it is determined that there is, the process of step S7 is repeated.

In this way, when the image of the one-page sentence is written, the process proceeds to step S11, it is judged whether or not a ready signal is coming from the printer engine unit, and it is confirmed that the ready state is obtained, S13
Proceed to.

In step S13, the signal 123 is turned on, the print I / F section, which has been in the power-off state until then, is turned on, and the print start signal 124 is sent to the printer engine section.

Then, in step S17, the print I / F control unit 107 is set to 1 in the bitmap memory 105.
Start data transfer for a page.

When the data transfer for one page is completed, the process proceeds to step S19, it is determined whether the data to be output next exists in the page memory 102, and if it exists, the process returns to step S7 and the next page is output. Print processing.

On the other hand, if it is determined that the unprinted data following the already transferred data is not in the page memory 102 even after the lapse of a predetermined period, the process proceeds to step S21 to shut off the power of the print I / F section. Signal 123 (OFF)
Signal) is output.

Now, the operation of the print I / F control unit 107 for transferring the bitmap data in the bitmap memory 105 to the scan buffer 108 will be described with reference to the flowchart of FIG.

The print I / F control unit 107 is actually
It operates in a hardware manner, and the processing procedure in the figure is not a flow for easy understanding.

First, in step S31, one line of data (data in the bit map data area + dot presence / absence information) is fetched from the bit map memory 105, and the data in the bit map data area is scanned into the scan buffer. Transfer to 108.

Then, in step S33, the dot presence / absence information of the transferred data is checked to determine whether or not there is a dot present state.

If the dot is present, the process proceeds to step S35 to set the signal 127 to be turned on after T1 time and turned off after T1 + T2 time. That is, T1 + T2 from T1 hours after the current time
Set the fuser motor to drive 127 over time. It goes without saying that the time T2 depends on the length of the recording paper.

Here, once the above time is set,
Even if data indicating that there is a dot is read from the second time onward, no processing is performed. The reset is performed in synchronization with the print start signal.
In addition, as a practical problem, in the present embodiment, since the dot presence / absence information is added in order to determine the case where there is no dot after the line with the page of interest, the data of the first line except for blank printing is added. The above time is set by transfer. That is, as a result, the time when the signal 127 is turned ON is a predetermined period before the time when the leading edge of the recording paper reaches the fixing device 206 (may be just before).

Next, when the processing proceeds to step S37, T6
When the time has elapsed, the signal 128 is set to ON, that is, the fuser heater is set to supply power. Similarly to step S35, once set, even if the dot presence / absence information 301 of the next line is "1", the process is not performed.

When the process proceeds to step S41, it is determined whether or not the data transfer for one page is completed, and if it is not completed, the process returns to step S31.

As the processing proceeds in this way, the line data having the dot presence / absence information 301 of "0" will be transferred to the scan buffer 108 at some point (of course, there are dots up to the last line). This is not the case). In this case, the process proceeds to step S39, and the signal 128 is turned off at the time when the position of the recording paper corresponding to the dot data of the target line reaches the fixing device 206, that is, after T6 time from this time (fixing device heater). Power off).

Next, the operation of the printer engine controller 601 on the printer engine side will be described with reference to the flowchart of FIG.

When the apparatus is powered on, step S
At 51, the signal from the jam sensor 604 or the like is checked to determine whether it is normal. If normal, step S
In step 53, the ready signal 122 to the printer controller side (input / expansion control unit 103) is turned on. When it is determined that the signal is not normal, the ready signal 122 is set to O.
Keep at FF.

When the process proceeds to step S55, it is determined whether the print start signal 124 is received.

If it is determined that the print start signal 124 has been received, the driver 603 is operated at step S57.
A conveyance motor (not shown) is driven via the to convey the recording paper to a predetermined position. Then, in step S59, the driver 6
03 via the polygon motor 202, the drum motor 2
The power source of the power source 09 is turned on to start driving. At this time, the laser driver 609 is also set in a drivable state.

In any case, the process proceeds to step S61, and thereafter, whether the signal 127 is ON or the signal 128 is ON,
If it is determined that one page has not been output and it is not tampered with, the processing from step S51 is restarted. However,
At this time, both the signal 127 and the signal 128 are in the OFF state, so the processes of steps S65 and S71 are performed, and the power supply to the fixing device motor 127 and the heater of the fixing device is cut off.

As a result of the above, the semiconductor laser device 20
From 1 on, the photosensitive drum is subjected to scanning exposure and development processing based on the video signal transmitted from 1 in accordance with a predetermined timing. Then, when the signal 127 from the printer controller side is detected to be ON (and is ON) during this process, the developed recording paper is conveyed to the vicinity of the fixing device 206. Since it means that it has been done, the process proceeds to step S63, the power of the fixing device motor is turned on, and the fixing device 06 is rotated.

Further, when the signal 128 is turned on, it means that it is time to fix the toner image on the recording paper. Therefore, the process proceeds to step S69, and the heater switch 6 of the fixing device is turned on.
A signal for instructing to turn on the power to the heater is output to 02.

On the other hand, when the signal 128 is turned off, the heater power switch 602 is instructed to turn off the power and the heating and holding of the heater is stopped even while the recording paper is being discharged to the outside by the fixing device 206. Let The reason is that, as described above, the toner is not transferred to the remaining portion of the recording paper sandwiched by the fixing device 206 at that time, and it is not necessary to fix the toner.

Thus, when it is detected that the recording paper for one page has passed the photosensitive drum 204 (detected by a sensor or the like), the polygon motor and the drum motor are stopped,
After that, the motor related to the carry motor is driven to carry out the recording paper to the outside. When ejecting, the fuser motor 2
Although 06 is also in a driving state, this fixing device 2
The power off of 06 is signal 1 from the printer controller side.
Controlled by 27.

Further, the motor of the carrying system is stopped when all the recording papers are carried and the next print start signal is not received.

As described above, according to the present embodiment, at least the power of the fixing device which consumes a large amount of power is turned on / off.
Is appropriately controlled based on the print data, so that power consumption can be significantly reduced. In addition, in the embodiment, in the print standby state, that is, when there is no data to be printed, the power of the print I / F unit (broken line portion in FIG. 1) on the printer controller side is turned off, and 1 If the print start signal due to the next data does not come after the development processing for the page is completed (if the de-print data transfer interval between pages is complete or one job is completed), the polygon motor or Since the power supply to the photosensitive drum etc. is turned off, it becomes possible to reduce the power consumption. Needless to say, the power supply to the charging device (not shown) or the transfer device can be controlled in synchronization with the power supply control to the photosensitive drum motor.

In the embodiment, the dot presence / absence information is updated every time one bit map data is written in the bit map memory 105, but the present invention is not limited to this. It may be checked when the image development for one page is completed.

[Explanation of Second Embodiment] The above-mentioned embodiment (first embodiment)
In the above embodiment), information indicating the presence or absence of dots, that is, the line after which the dots do not exist is stored and held in the bitmap memory. However, the present invention is not limited to this.

For example, the last line in which dots exist is stored, the stored line number is compared with the line number to be transferred, and when the latter exceeds the former, the processing as in the above embodiment is performed. May be.

FIG. 5 shows a block diagram of the printer controller side in the second embodiment as described above. The difference from FIG. 1 is that a counter 501 is provided. This counter 501 has an input / deployment control unit of 1
Bitmap data for pages is stored in bitmap memory 1
The address in the vertical (Y) direction when 05 is accessed is monitored, and the largest address is always held.

When the print I / F control unit 107 transfers to the scan buffer 108 in units of one line after the development of the bitmap data for one page is completed, the signal 50 is output.
When 2 is output and the countdown is performed, and when it is "0", the same processing as in the first embodiment described above is performed.

[Explanation of Third Embodiment] In addition,
In the second embodiment, it is determined whether or not the dot data does not exist after that. However, it is generally unlikely that there is a dot even when it is within the recordable range when recording on the recording paper.

Therefore, when the data is expanded in the bit map memory for one page, information indicating from the head line to which line the dots do not exist is newly added, and thus the first or second line is added. It may be adapted to the embodiment.

For example, in the case of adapting to the first embodiment, as shown in FIG. 10, the dot presence / absence information of the area B from the first line where dots are present to the last line is set to "1", The areas A and C other than the above areas are set to "0".

The heater is turned on before the transferred recording paper corresponding to the area B passes through the fixing device 206 (time required for the fixing device to reach an appropriate temperature). However, the drive timing of the transfer unit motor is the same as that in the above embodiment.

Further, in the case of adapting to the second embodiment, two counters a and b (not shown) are prepared, and the first line of the area B is held in the counter a and the last line is held in the counter b. Let Each time one line of data is transferred, the counters a and b are decremented, and the power to the heater is turned on two hours after the counter a becomes "0", and the counter b is set to "0". It is sufficient to turn off the power source of the heater after T2 hours from the time when "".

In any case, there may be lines with no dots in region B, which are ignored. The reason is that it is not realistic to turn on / off the heater for each line. However, it goes without saying that this may be done.

In this embodiment, the case where the control systems of the printer controller section and the printer engine section are independent of each other has been described, but the present invention is not limited to this, and one control section configures the entire apparatus. Of course, it can be applied to control. Further, in the embodiment, the laser beam printer has been described as an example, but the invention is not limited to this. That is, the gist of the present invention is
This is because it makes sense to supply power to the relevant parts only when it is actually needed. Therefore, the fact that it can be applied to a digital color copying machine (an apparatus that temporarily stores image data in a memory and performs a predetermined process for copying) and a printer of another system is easily applicable from the above description. You can understand.

Further, it goes without saying that the processing contents of the embodiment may be realized by a program or hardware.

[0086]

As described above, according to the present invention, wasteful power consumption can be suppressed by controlling the power supply timing to each drive system involved in the printing process depending on the image to be printed. Will be possible.

[0087]

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a printer controller unit of a printing apparatus according to an embodiment.

FIG. 2 is a diagram illustrating a structure of a printer engine unit of the printing apparatus according to the embodiment.

FIG. 3 is a diagram showing a relationship between dot data developed in a bitmap memory and dot presence / absence information.

FIG. 4 is a timing chart showing the operation of the embodiment, and is a diagram showing ON / OFF control of power supply around the fixing device.

FIG. 5 is a block configuration diagram of a printer controller unit in a second embodiment.

FIG. 6 is a block configuration diagram of a control system of a printer engine unit in the embodiment.

FIG. 7 is a flowchart showing an operation processing procedure on the printer controller side in the embodiment.

8 is a flowchart showing details of output processing in FIG.

FIG. 9 is a flowchart showing the operation processing contents of the printer engine control unit on the printer engine side in the embodiment.

FIG. 10 is a diagram showing a storage state of a bitmap memory in the third embodiment.

[Explanation of symbols]

 101 Input I / F Unit 102 Page Memory 103 Input / Development Control Unit 104 Font ROM 105 Bitmap Memory 106 Printing I / F Unit Power Supply Control Unit 107 Printing I / F Control Unit

Claims (3)

[Claims] 1. A printing device for printing an image on a predetermined recording medium, a detection means for detecting a dot distribution of an image to be printed, and a drive system for a series of printing processes based on the detected dot distribution. And a control unit that controls a power supply timing to the printing apparatus. 2. A thermal fixing device is included in one of the drive systems, and the detecting means detects a final line having dot information and a line after that from a head position of an image in an image of one page, and performs the control. The means for starting power supply to a heater for heating the thermal fixing device before a predetermined arrival of a portion of the recording medium where it is determined that the dots exist in the thermal fixing device. The printing device according to. 3. A discriminating means for discriminating whether or not an image to be printed exists, and stopping the power supply to the drive system which has been determined to be completed when there is no image to be printed. The printing apparatus according to claim 1, further comprising two control means.