JP3174233B2 - Image forming apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and an image forming method, and more particularly to an image forming apparatus and an image forming method for forming one image by different image forming methods.

[0002]

2. Description of the Related Art As a printer for printing text data sent from a host computer, a laser beam printer (hereinafter referred to as "LB") which is a so-called non-impact printer with low noise and has a feature that high resolution printing is possible.
P ”) and inkjet printers (hereinafter“ IJP ”). Furthermore, LBP is superior to IJP in the quality and printing speed of black-and-white printing, while IJP is characterized in that color printing is easy.

In order to take advantage of the features of the two printers, a method has been proposed in which two printing-type printers are incorporated in one apparatus and linked to perform printing.
This is because even if a color image is printed, the character part is often black and white, so the black and white character part is
It is intended to print in the LBP section and print in the IJP section for the color part. By using such a printing apparatus, it is possible to realize a printer having a black-and-white printing speed equivalent to that of an LBP and capable of easily printing a color image.

[0004]

However, the above conventional example has the following problems. That is, since the LBP unit and the IJP unit require a memory for developing images separately, there is a disadvantage that the cost does not decrease despite the multifunction peripheral.

An object of the present invention is to solve the above-mentioned problem. When sending bitmap data of an image to an image forming unit of a different system, a memory for expanding the bitmap data is shared. The purpose is to: Another object of the present invention is to prevent printing failure due to memory over when sharing a memory for developing bitmap data.

[0006]

The present invention has the following configuration as one means for achieving the above object. The image forming apparatus and the method according to the present invention, when inputting image information from an external device and forming an image by an electrophotographic method or an ink jet method, based on the input image information, by an electrophotographic method or an ink jet method. After the bitmap data of the image to be formed is developed in the memory, the bitmap data of the first image formed by the electrophotographic method is developed in the memory, and the first image is formed by the electrophotographic method. The bitmap data of the second image formed by (1) is developed in a memory, and the second image is formed by an inkjet method.

Further, when image information is input from an external device and an image is formed by an electrophotographic method or an ink jet method, a bit map of an image formed by an electrophotographic method or an ink jet method is formed based on the input image information. The data is expanded in a memory, and bitmap data for one page of an image formed by the electrophotographic method cannot be stored in the memory. When it is not possible to develop the bitmap data in time, an image of the bitmap data developed in the memory is formed by an ink jet method.

When image information is input from an external device and an image is formed by an electrophotographic method or an ink jet method, a bit map of an image formed by an electrophotographic method or an ink jet method is formed based on the input image information. When data is developed in a memory and bitmap data for one page of an image formed by an electrophotographic method cannot be stored in the memory, an image of bitmap data stored in the memory is formed by an ink jet method. And

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view of an image forming apparatus according to an embodiment of the present invention. Reference numeral 101 denotes a hybrid printer of the embodiment. Reference numeral 100 denotes a host computer which sends print information including text data to the hybrid printer 101. is there.

The hybrid printer 101 has the following configuration. 102 is an LBP printing unit, 103 is an IJP printing unit, 104 is a conveyance unit that conveys recording paper from the LBP printing unit 102 to the IJP printing unit 103, 105 is a controller, 106 is a host computer 10
Interface cable with 0.

FIG. 2 is a block diagram showing a configuration example of the controller 105.

Reference numeral 201 denotes a CPU, 202 denotes a RAM, and 203 denotes a ROM. CP
U201 controls the entire hybrid printer 101 according to a program stored in the ROM 203 in advance, and stores character codes and the like included in print information transmitted from the host computer 100 in the ROM 203 in advance, using the RAM 202 as a work. An operation such as expansion into bitmap data according to the specified character font is performed.

FIG. 9 is a diagram showing the details of the area secured on the RAM 202. Three areas of a page memory 901, a bit map memory 902 and a work memory 903 are secured. Further, as will be described in detail later, the bitmap memory 902 in which the print information is expanded has a case where the bitmap memory 902 is used at 2,400 × 256 dots indicated by reference numeral 902a and a case where the YMCK is indicated by reference numeral 902b.
There are a case where it is used with × 64 dots and a case where it is used with 2,400 × 64 dots of four Ks indicated by reference numeral 902c.

Referring again to FIG. 2, reference numeral 204 denotes an input unit for inputting print information sent from the host computer 100 via the interface cable 106. 206 is LBP-I / F,
In accordance with a command from the CPU 201, the print data is sent to the LBP printing unit 102 to perform printing. Reference numeral 207 denotes an IJP-I / F, which sends print data to the IJP printing unit 103 to perform printing in accordance with a command from the CPU 201. 221 is a display unit. 209 is an extended RAM-I / F,
Although details will be described later, this is for connecting an optional extended RAM 208. These configurations are based on the CPU bus 201a.
Are connected to each other.

FIG. 3 is a block diagram showing an example of the internal configuration of the LBP-I / F 206. Reference numeral 303 denotes a scan buffer which includes buffers 304 and 305 each having a capacity of one line, and stores input dot pattern data 302. Buffer. A parallel / serial converter 306 converts the parallel data output from the scan buffer 303 into serial data 321, and converts the data into a serial data 321.
Send to 2. Reference numeral 301 denotes a control unit which controls the scan buffer 303 and the parallel / serial converter 306 in synchronization with the horizontal and vertical synchronization signals sent from the LBP printing unit 102, and sends serial data 321 to the LBP printing unit 102.

That is, while the dot pattern data 302 is being written to one of the buffers 304 or 305, the LBP-I / F 206 reads out the dot pattern data from the other buffer, converts the dot pattern data into serial data 321, and performs LBP printing. It has a so-called double buffer configuration for sending to the unit 102.

FIG. 4 is a block diagram showing an example of the internal configuration of the IJP-I / F 207. Reference numeral 401 denotes a vertical / horizontal conversion unit, which prints the print data developed in the raster direction in the IJP printing unit 103 arranged in the line direction. The vertical and horizontal are switched in units of 64 × 64 dots for each color according to the arrangement of. A double buffer 402 has the same function as the scan buffer 303 of the LBP-I / F 206. 403 is a register, double buffer 4
It receives the YMCK 64-bit data output from 02 and sends it to the IJP printing unit 103 as print data 422. A control unit 404 reads dot data in synchronization with the horizontal and vertical synchronization signals sent from the IJP printing unit 103, and
Send to

Next, an outline of the printing operation of the hybrid printer 101 will be described.

The laser element 1023 shown in FIG. 1 is turned on / off according to the dot pattern data 321 sent from the LBP-I / F 206 of the controller 105. The laser beam 1024 emitted from the laser element 1023 scans on the photosensitive drum 1027 by the rotating polygon mirror 1026 driven by the motor 1025. Photosensitive drum exposed by laser beam 1024
The latent image on 1027 is developed as the photosensitive drum 1027 rotates.
The toner image is developed by 1028. Photosensitive drum 1027
The upper toner image is transferred to a paper feed roller 1022 by a transfer unit 1029.
Is transferred onto the recording paper 1021 conveyed by the printer and further fixed by the fixing device 1030, and the printing in the LBP printing unit 102 ends.

The recording paper 10 that has been printed by the LBP printing unit 102
21 is sent to the paper feed roller 1031 of the IJP printing unit 103 through the intermediate conveyance unit 104. The midway transport unit 104 includes the LBP printing unit 102
The buffer also absorbs the difference between the printing speeds of the IJP printing unit 103 and the IJP printing unit 103. This is because the LBP printing unit 102 has a higher printing speed than the IJP printing unit 103 and cannot stop the printing operation in the middle. Therefore, the intermediate transfer unit 10
The transport path length of 4 is set to be longer than the maximum length of the recording paper 1021.

When the printing on the new recording paper 1021 is enabled, the IJP printing unit 103 rotates the paper feed roller 1031 to
The recording paper 1021 is guided to the IJP head 1032. IJP head 1032
As shown in an example in FIG. 5, this is a form in which four heads for each color having 64 print nozzles arranged in the recording paper transport direction are bundled in a direction orthogonal to the recording paper transport direction. By scanning the IJP head 1032 in a direction orthogonal to the recording paper conveyance direction, printing for 64 lines is performed per scan.

Recording paper 10 printed by IJP printing unit 103
21 is a hybrid printer 101 with a paper discharge roller 1033
And the printing is completed.

Next, the operation of the controller 105 will be described. 6 to 8 are flowcharts illustrating an operation example of the controller 105, which is executed by the CPU 201 when print information is sent from the host computer 100.

In step S 1, the data sent from the host computer 100 is received by the input unit 204 and
The data is stored in the page memory 901 secured in 2. The page memory 901 has a size sufficient to store one page of data such as text data / commands and graphics data / commands. Generally, the data size of one page of the A4 size of text data / command or graphics data / command is 20 Kbytes to 30 Kbytes, whereas a page memory 901 of, for example, about 200 Kbytes may be secured.

Next, in step S2, it is determined whether or not one page of data has been received. If it has been received, the process proceeds to step S3, where the data stored in the page memory 901 is analyzed, and Divide into command / data and color command / data. This is because monochrome data is printed by the LBP printing unit 102, which prints at high speed and has excellent print quality, while color data is printed by the IJP printing unit 103.

If one page of data has not been received, the process proceeds to step S4, where it is determined whether or not the received data has exceeded the size of the page memory 901, and if not, the process returns to step S1. Continue to host computer
Receives data sent from 100. On the other hand, there are two possible reasons why the page memory 901 becomes full before data of one page is completely received.

One is that the input data is stored in a page memory.
In the case of bit image data exceeding the size of 901
For example, A4 size 300dpi bit image data for one page is about 1M
Bytes, and slightly exceeds the page memory 901 of about 200 Kbytes as described above. Second, even if the input data is only text commands / data or graphics commands / data, for example, if the data is such that the same character string is repeatedly printed at the same position on the page many times, the page memory 901 is used. It will be over. Otherwise, even if the input data represents a complex image, the page memory 90
May exceed 1. In such a case, a page printer such as an LBP that handles data in page units prints if it cannot secure a full-size bitmap memory (a bitmap memory for one page, hereinafter referred to as “full bitmap memory”). Can not do.

In step S5, the size of the extension RAM 208 is checked. In step S6, it is determined whether or not a full bitmap memory can be secured in the extension RAM 208. If the full bitmap memory cannot be secured, the LBP is determined in step S7. -Send a print start signal 322 to the LBP printing unit 102 through the I / F 206 to
The printing unit 102 supplies and transports the recording paper 1021.
However, at this time, the dot pattern data 321 sent to the LBP printing unit 102 continues to be FALSE (white data).
21 passes the LBP printing unit 102 that the image is printed,
It reaches the IJP printing unit 103 via the conveyance unit 104 on the way. Next, in step S8, the data stored in the page memory 901 is developed in the bitmap memory 902, and the IJP printing unit 103
It is determined in step S9 whether printing for one page has been completed. If the printing has not been completed, the next data is received from the host computer 100 in step S10, and the process returns to step S8. When printing of one page is completed by the processing from step S8 to step S10, the processing is terminated.

If it is possible to secure a full bitmap memory on the extension RAM 208, the process proceeds to step S11, where the data stored in the page memory 901 is transferred to the extension RAM 208.
The data is expanded in the full bitmap memory secured in 208, and it is determined whether or not the expansion of the data for one page is completed in step S12. If not completed, the next data is received from the host computer 100 in step S13. After that, the process returns to step S11. When bitmap data for one page is obtained by the processing from step S11 to step S13, LBP is obtained in step S14.
After printing is performed by the printing unit 102, the process jumps to step S22.

FIGS. 6 to 8 show only the printing procedure for one page. However, when data of the second and subsequent pages is sent from the host computer 100, the process returns to step S1 to repeat the above-described processing. become.

On the other hand, if the data is divided in step S3, it is determined in step S15 whether or not there is a black-and-white command / data. If not, the process proceeds to step S16, where the LBP printing unit 10
Since there is no data to be printed in step 2, after the recording paper 1021 is conveyed to the LBP printing unit 102 as in step S7 described above, the process jumps to step S24.

If there is a monochrome command / data, the flow advances to step S17 to determine whether a full bitmap memory can be secured. If full bitmap memory cannot be allocated, use bitmap memory
Since 902 is used as a so-called band memory, in step S18, it is determined whether or not it is time to develop the bitmap data in the bitmap memory 902 while transmitting the dot pattern to the LBP printing unit 102. judge.

As shown in an example in FIG. 9, when the bit map memory 902 is used like the code 902a, 256 lines of 2,400 dots per line (the number of dots in the recording paper width direction) are used. The map can be stored, for example, since the longitudinal direction of A4 size is about 296 mm, if you try to print this at 300 dpi, it will be about 3,500 lines, a bit map of about 1/14 minute (256 / 3,500) This is because only data can be expanded. To elaborate,
The CPU 201 sequentially stores the data of the lines on which the dot pattern data has been developed into the bitmap memory 902 by using the LBP-I /
The data is sent to F206, and the dot pattern data of the next line is developed in the memory where the dot pattern of the sent line is stored. Therefore, for example, when commands for drawing a complicated figure are concentrated, the development of the dot pattern data cannot catch up with the timing of sending the dot pattern data to the LBP-I / F 206, and printing cannot be performed. To avoid this situation, the CPU 201 estimates the time required to check the input data and develop the dot pattern, and determines whether the development of the dot pattern is faster than sending the dot pattern data to the LBP-I / F 206. Judge whether or not.

In order to estimate the development time, each command /
If the time required for the development process is recorded in advance for each data, it can be easily calculated. Specifically, when there are instructions to draw Z characters, lines and circles in 256 lines, the time required for the expansion processing
T seconds are expressed by the following equation. T = Y × Z + V + W… (1) where Y: time to generate and develop character pattern from character code V: time to draw line W: time to draw circle

Assuming that the scanning time per line of the LBP printing unit 102 is t seconds, the time required to scan 256 lines per band is 256 t seconds. In other words, if the following expression is satisfied, the dot pattern is developed in time for printing by the LBP printing unit 102. T <256t… (2)

Therefore, when the expression (2) cannot be satisfied, that is, when the development cannot be made in time, the process proceeds to step S16, where the recording paper 1021 is conveyed to the LBP printing unit 102, and then the process jumps to step S24.

If the full bitmap memory can be secured, or if the development is in time even if the full bitmap memory cannot be secured,
In step S19, the data stored in the page memory 901 is expanded to the bitmap memory 902, and in step S20, the dot data in the bitmap memory 902 is sent to the LBP printing unit 102 for printing.In step S21, printing of one page is performed. It is determined whether or not the process has been completed, and if not completed, the process returns to step S19.

When the printing of one page by the LBP printing unit 102 is completed in the processing of step S19 to step S21 or the processing of step S14, and the recording paper 1021 is conveyed to the entrance of the IJP printing unit 103, in step S22 It is determined whether or not the page has data to be printed by the IJP printing unit 103.
In step S23, the IJP printing unit 103 is activated to convey the recording paper 1021 and discharge the recording paper 102 out of the apparatus. Then, the processing ends.

If it is determined in step S23 that there is data to be printed by the IJP printing unit 103, if it is determined in step S18 that dot data cannot be developed in time, it is determined in step S15 that there is no monochrome command / data. In either case, the data in the page memory 901 is expanded in the bit map memory 902 in step S24 and printed by the IJP printing unit 103, and then the process is terminated.

As described above, in step S23, the IJP printing unit 103
If it is determined that there is data to be printed in
The recording paper 1021 printed in 02 is overlaid and printed by the IJP printing unit 103. Also, if it is determined in step S18 that the dot data cannot be expanded in time, or if step S1
If it is determined that there is no black / white command / data in 5, LBP
The IJP printing unit 103 is placed on the recording paper 1021 that has passed through the printing unit 102.
Will be printed.

When printing is performed by the LBP printing unit 102, the CP
The U201 analyzes the input data, and in accordance with the command, refers to the character font information in the ROM 203 for the character code, converts it into dot pattern data, and develops it into the bitmap memory 902. In the case of the full bitmap memory, when the dot pattern data for one page is completed, and in the case of the band memory, the dot pattern data for the band is completed, the LBP printing unit via the LBP-I / F206. 1
Send a print start signal 322 to 02. Upon receiving the print start signal, the LBP printing unit 102 starts supplying the recording paper 1021, and starts rotating the rotating polygon mirror 1026 and the photosensitive drum 1027. When the rotation of the rotating polygon mirror 1026 and the photosensitive drum 1027 reaches a predetermined value and the recording paper 1021 reaches a predetermined position, the LBP
The printing unit 102 outputs a horizontal synchronization signal 323 to synchronize the transport timing of the recording paper 1021 with the dot pattern data.
And a vertical synchronization signal 324 to the LBP-I / F 206. LBP-I / F20
The control unit 301 of 6 sends the dot pattern data 321 to the LBP printing unit 102 in synchronization with these signals, and writes the data of the next line to one buffer of the scan buffer 303.

When printing is performed by the IJP printing unit 103, the CP
The U201 divides the bitmap memory 902 into bands of 64 lines each of YMCK corresponding to one scanning width of each head, and develops a dot pattern into each band, as shown by 902b in FIG. However, if the input data is black and white data only,
As shown in 9 902c, the printing efficiency is improved by dividing the band into four bands of K64 lines. CPU 201 is a bitmap memory
When dot pattern development to 902 is completed, IJP-I / F20
A print start signal 421 is sent to the IJP printing unit 103 via. The IJP printing unit 103 activates the paper feed roller 1031 and
While guiding the recording paper 1021 to the head 1032, the IJP head 103
2 is scanned left and right, and a horizontal synchronization signal 423 and a vertical synchronization signal 424 are sent to the IJP-I / F 207. The control unit 404 of the IJP-I / F207
Dot pattern data 422 is synchronized with these signals
Send to printing unit 103.

When the bit image data is printed using the band memory, the next data (bit image data) is input from the host computer 100 and printed at step S10 every time the band memory becomes empty. . Also,
In step S7 or step S16, the recording paper 1021
When passing through the BP printing unit 102, the power of the fixing unit 1030 of the LBP printing unit 102 is turned off.

As described above, according to the present embodiment,
Reduce the cost of hybrid printers by securing and sharing the bitmap memory that expands the dot pattern sent to the LBP printing unit and the bitmap memory that expands the dot pattern sent to the IJP printing unit on one memory be able to.

If there is no image to be printed in black and white, the time required to develop the black and white image to the band memory is longer than the time to send the dot pattern data developed from the band memory to the LBP printing unit, If the size of the image to be printed exceeds the band memory size, improve the efficiency and printing efficiency of the hybrid printer by passing the recording paper straight through the LBP printing unit and printing all dot patterns with the IJP printing unit. can do.

In the drawings and the above description,
Although the configuration in which the IJP printing unit 103 is arranged following the LBP printing unit 102 has been described, this order may be reversed. Furthermore, in the case of black and white printing, when there is little data to be printed, it may be faster to print with the IJP printing unit 103.In such a case, the recording paper 1021 is passed through the LBP printing unit 102 without passing. , And can be printed by the IJP printing unit 103.

The present invention may be applied to a system constituted by a plurality of devices or to an apparatus constituted by a single device.

It is needless to say that the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus.

[0050]

As described above, according to the present invention,
When transmitting bitmap data of an image to an image forming unit of a different system, a memory for developing the bitmap data can be shared. Further, when sharing the memory for expanding the bitmap data, it is possible to prevent printing failure due to memory over.

[Brief description of the drawings]

FIG. 1 is a schematic view of an image forming apparatus according to an embodiment of the present invention;

FIG. 2 is a block diagram showing a configuration example of a controller shown in FIG. 1;

FIG. 3 is a block diagram showing an example of the internal configuration of the LBP-I / F shown in FIG. 2;

FIG. 4 is a block diagram showing an example of the internal configuration of the IJP-I / F shown in FIG. 2;

FIG. 5 is a diagram showing an example of the configuration of the IJP head shown in FIG. 1,

6 is a flowchart showing an operation example of the controller shown in FIG. 2,

7 is a flowchart showing an operation example of the controller shown in FIG. 2,

8 is a flowchart showing an operation example of the controller shown in FIG. 2,

FIG. 9 is a diagram showing details of an area secured on a RAM shown in FIG. 2;

[Explanation of symbols]

 100 Host computer 101 Hybrid printer 102 LBP printing section 103 IJP printing section 104 Intermediate transport section 105 Controller

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-312540 (JP, A) JP-A-7-266631 (JP, A) JP-A-7-232463 (JP, A) JP-A-7- 101083 (JP, A) JP-A-8-174809 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/01 B41J 2/44 B41J 2/475 G06F 3/12

Claims (8)

(57) [Claims] An input unit configured to input image information from an external device; a first forming unit configured to form an image by an electrophotographic system; a second forming unit configured to form an image by an inkjet system; deployment of based on more input image information
The, formed by the first or second forming means
A memory in which bitmap data of an image is stored, and a bit of a first image formed by the first forming unit.
The map data is expanded in the memory, and the first image is
After being formed by the first forming means, the second forming means
Bitmap data of the second image formed by the steps
Expands the image in the memory and stores the second image in the second form
An image forming apparatus comprising: a control unit configured to be formed by a forming unit. 2. The method according to claim 1, wherein the control unit is configured to control one page of the first image .
Is developed in the memory, and the
Sending one page of bitmap data to the first forming means;
After that, the bitmap data of the predetermined width unit of the second image is
Data in the memory, and the bits of the predetermined width unit
2. The image forming apparatus according to claim 1, wherein the map data is sent to the second forming unit. Wherein the control means, not contain a picture to be formed in black and white in the image information, according to claim 1 recording medium and controls to pass through the first forming means or The image forming apparatus according to claim 2. 4. An input device for inputting image information from an external device.
Step, first forming means for forming an image by electrophotography, and second forming means for forming an image by ink jet method
When deployment of on the basis of the image information input by said input means
Formed by the first or second forming means
A memory in which bitmap data of the image is stored, and a video for one page of the image formed by the first forming means.
Data cannot be stored in the memory, and
While sending bitmap data to the first forming means
Between the bitmap data and the memory
If they do not match, the bitmap data expanded to the memory
Control means for causing the second forming means to form a data image
An image forming apparatus characterized by chromatic and. 5. An input device for inputting image information from an external device.
Step, first forming means for forming an image by electrophotography, and second forming means for forming an image by ink jet method
When deployment of on the basis of the image information input by said input means
Formed by the first or second forming means
A memory in which bitmap data of the image is stored, and a video for one page of the image formed by the first forming means.
If the map data cannot be stored in the memory,
The image of the bitmap data stored in the memory
An image forming apparatus characterized by chromatic and control means for forming the second forming means. An input step of 6. inputs image information from an external device, a first forming step of forming an image by an electrophotographic system, a second formation step of forming an image by ink jet method
And the image information input in the input step,
Of the image formed by the first or second formation step
A developing step of developing bitmap data in a memory ; and a video of the first image formed by the first forming step.
Expands the map data into the memory,
After forming an image by the first forming step,
Bits of the second image formed by the second forming step
The map data is expanded in the memory, and the second image is
A controlling step to be formed in the second forming step.
Image forming method characterized by chromatic. 7. An input device for inputting image information from an external device.
Tep, A first forming step of forming an image by electrophotography, The second forming step for forming an image by the ink jet method
And Based on the image information input in the input step,
Of the image formed by the first or second forming step
Expansion step of expanding bitmap data in memory
When, One page of the image formed by the first forming step
Bitmap data cannot be stored in the memory,
And sending bitmap data to the first forming step.
Expand bitmap data to the memory
If it is too late to be
Forming an image of map data in the second forming step
Image forming having a control step of causing
Method. 8. An input device for inputting image information from an external device.
Tep, A first forming step of forming an image by electrophotography, The second forming step for forming an image by the ink jet method
And Based on the image information input in the input step,
Of the image formed by the first or second forming step
Expansion step of expanding bitmap data in memory
When, One page of the image formed by the first forming step
If the bitmap data cannot be stored in the memory
The bitmap data image stored in the memory
In the second forming step.
An image forming method comprising: