JP2003270881A - Image forming apparatus and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus not necessitating generation information required for toner replenishment control on a printer engine side, and to provide a printer engine at a low cost. <P>SOLUTION: The prediction data of the toner consumption for inputted image data are generated in an image processing part (4), and the formed prediction data are supplied by a CPU (101) to the printer engine (5). Thereby, the toner replenishment is controlled by the printer engine (5) on the basis of the supplied prediction data. <P>COPYRIGHT: (C)2003,JPO

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 for forming an image on a recording medium using a developer based on supplied data and a control method therefor.

[0002]

2. Description of the Related Art In recent years, a WWW carrying various information
(World Wide Web) server and HTTP (H
By connecting a computer equipped with dedicated software (hereinafter referred to as a browser) for accessing by the yper Text Transfer Protocol) through a network, it is possible to refer to the information on the WWW server from the computer. Further, this browser can capture and store the information on the WWW server in the computer.
Therefore, a user who wants to print this data can also print various data of the WWW server by outputting the data temporarily stored in the computer to a printer device having a printing function to print the data. it can.

In printing, if fixed image processing is always performed regardless of the content of the information, gradation and resolution may be impaired, so image processing is performed according to the type of image data. It is desired to form an image.

By the way, with the recent integration of hardware, processing for acquiring image data from a network, expanding the acquired image file into a raster image, and performing image processing for obtaining an appropriate print image, etc. Circuits have become built in the image forming apparatus rather than the computer side.

Further, conventionally, in an image forming apparatus such as an electrophotographic digital copying machine which obtains a print image by converting a document image into image data by a reading device, the image data is transmitted via an external device of the image forming apparatus. It is possible to get.

Further, in the image forming apparatus configured as a printer which is a computer peripheral device, various image processing boards can be attached according to the user's request, and a product tailoring that achieves both the cost and the function desired by the user is provided. It has been demanded. That is, a part or all of the image processing circuit of the image forming apparatus is required to be replaceable.

Under these circumstances, the image forming apparatus (printer engine) side of the image forming apparatus does not have the main image processing, but the image control section generally provided by the image processing board has the main image processing functions. By doing so, an attempt has been made to provide the printer engine itself at low cost.

As described above, while the flexibility of the configuration of the image processing circuit is required, the image processing circuit is becoming more sophisticated and complicated, and various image processings have been proposed according to the characteristics of the original image and the image data. Appropriate image processing has come to be performed automatically or in response to a user's instruction, and it has become difficult to distinguish between control by the image control unit and control on the printer engine side.

Particularly, in a printer system having a function of predicting toner consumption amount according to image data and controlling toner density, image processing such as gamma conversion, which is conventionally closely related to printer control, is performed by the printer engine side. I was responsible for it. That is, as a part of controlling the image forming unit of the image forming apparatus, the printer engine side mainly performs image processing according to the engine characteristic to correct the engine characteristic, and the printer engine receives the image data. Then, the image data is integrated, the toner consumption amount is predicted from the integrated result, and the toner replenishment control to the developing device is performed.

Further, a toner patch image is formed on the photosensitive drum, the toner density in the developing device is measured, and the toner replenishment control is highly accurate based on the integrated result of the image data and the measured toner density information in the developing device. There is also proposed an image forming apparatus adapted to perform the above.

[0011]

In order to provide various image processing functions by replacing the image processing board, it is necessary to handle information necessary for printer engine control not on the printer engine side but on the image control unit side. It came out. However, in the conventional image forming apparatus, as described above, the printer engine side exclusively handles the information necessary for toner replenishment control, which is closely related to the printer characteristics. Therefore, there is a problem that the main image processing functions cannot be integrated in the image control unit and the printer engine itself cannot be provided at low cost.

The present invention has been made in view of the above conventional example, and realizes an image forming apparatus that does not need to generate information necessary for toner replenishment control on the printer engine side, thereby providing a printer engine at low cost. The purpose is to do.

[0013]

In order to achieve the above object, for example, an image forming apparatus of the present invention has the following configuration.

An image forming means for forming an image on a recording medium based on the supplied data, and a control means for controlling the supply of the image data to the image forming means are provided with a developing device for accommodating a developer. In the image forming apparatus, the control unit includes a prediction unit that generates prediction data of developer consumption for input image data, and a supply unit that supplies the generated prediction data to the image forming unit. ,
And the image forming unit includes a replenishment control unit that controls replenishment of the developer to the developing device based on the supplied prediction data.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing this embodiment in detail, first, the features of image processing in this embodiment will be briefly described.

For example, currently on the Internet,
GIF, JPEG, etc. are generally used as the image file format. Of these, the GIF file format is a file format in which an image is compressed by lossless compression and saved, and the number of colors that can be displayed is limited to 256 colors. Therefore, the GIF file format is often used for image data that does not require a large number of colors, such as illustrations and drawings.

Further, the JPEG file format is a file format which is compressed and stored by irreversible compression, and it is possible to display a very large number of colors such that the number of colors that can be displayed is about 16.77 million. For this reason, this JPEG file format is often used mainly for image data of natural images such as data obtained by digitizing photographs.

On the other hand, in printing an image by an electrophotographic method or the like, if the resolution of the image to be printed is increased, it is difficult to make the waveform of an analog signal used as a pattern signal by pulse width modulation or the like an ideal triangular wave. Therefore, it becomes difficult to print with ideal gradation.

Therefore, in the present embodiment, an image for which resolution is important is printed at high resolution, and an image for which color gradation is emphasized is printed at low resolution.

Further, since image data such as illustrations and drawings and image data such as photographs and natural images often have different settings for image enhancement processing or smoothing processing, in the present embodiment, each image data is set. It is possible to set the image enhancement or smoothing according to the format.

In addition, when the RGB type image data is printed by the electrophotographic type printer, the image data expressed in RGB is C (cyan), M (magenta),
It is necessary to convert the density values of Y (yellow) and K (black) and send the converted image data to the printer. In this case, in a gray-color image printed using the toner as the CMY developer, the gray color becomes a tinge gray, and therefore the gray portion is formed only by the black (K) toner. It may be better to print. vice versa,
When a gray portion is printed with only black toner, in the case of a gradation image in which gray changes to another color gently, the reproduced gradation property of the gradation portion is impaired. Therefore, in such an electrophotographic printer, the CM
Generally, Y toner and K toner are combined in an appropriate ratio to form an image. CM in this case
Under color removal (Under
Color Removal). In this embodiment, it is possible to set the under color removal according to the format of each image data.

In the case of a printer, such as a binary printer, in which the area of one pixel is not variable or can be changed only by a very limited amount, the unit area is It is possible to print an image with gradation by changing the number of colored pixels per hit or the combination of these colored pixels. Such an image representation method is called area gradation. According to this method, the original image data is converted into image data composed of only printable colors in the printer by dither processing or error diffusion method and printed. can do. Even in such area gradation processing, the optimum conversion processing is applied depending on the format of each image data when printing image data such as a photograph and when printing image data such as an illustration. The area gradation processing can be set.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First Embodiment> In the present embodiment, the HT
Using the TP protocol, first, a command is transmitted to a server that holds desired image data instructed by the user using the operation unit, and the command is stored in that server in response to a reply from the server. An image forming apparatus that can acquire the image data stored and form an image will be described.

FIG. 1 is a block diagram showing the configuration of the image forming apparatus 1 of this embodiment, which is connected to a network 32.

In FIG. 1, reference numeral 2 denotes an image memory, which holds, for example, image data obtained by the reading unit 202 or image data input from the network 32 via the network interface 3. The network interface 3 controls communication with other devices connected to the network 32 via the network 32. An image processing unit 4 performs various kinds of image processing on the image data stored in the image memory 2 and outputs the processed image data to the printer 5. A printer engine (hereinafter, simply referred to as a printer) 5 functions as an image forming unit that inputs image data from the image processing unit 4 and forms an image on a recording medium such as paper. An operation unit 6 is used to specify a place (a server or the like) where image data to be printed is held by using the printer 5. A server 7 is connected to the network 32 and holds various image data. Reference numeral 30 denotes a system bus, which is a bus for transmitting and receiving data between the CPU 101 which controls the operation of the entire image forming apparatus 1 and each unit. A video bus 31 is used for transmitting the image data generated by the image processing unit 4 to the printer 5. Network 32
Is a communication path for connecting the image forming apparatus 1 and the server 7 to each other and for transmitting and receiving various data between these apparatuses. Reference numeral 102 denotes a memory, which is also used as a work area for temporarily storing programs executed by the CPU 101 and various data when the CPU 101 operates.

Note that, for example, the CPU 101, the image memory 2, the network interface 3, the image processing unit 4, and the memory 102 described above function as an image control unit and can be mounted as an image processing board.

The CPU 202 of the printer 5 is the CPU 10
Data is transmitted and received to and from the printer 1, and a series of printer engine process controls such as paper transport control of the printer 5, toner image formation and toner replenishment operation, transfer onto paper, and fixing process are performed.

The original image set on the reading unit 202 is
The image data is converted into image data based on a pressing event of the copy key of the operation unit 6 and stored in the image memory 2. Then, the image data is subjected to predetermined image processing by the image processing unit 4,
The image is sent to the printer 5 and an image is formed on the recording medium.

Next, the HTTP protocol will be described.

The HTTP protocol is a service on the TCP / IP protocol used to transfer data described in HTML (Hyper Text Markup Language), image data, and the like. This is usually used in a system in which a client computer that issues a data transfer request and a server that holds data are connected by a network.

On the client computer, the HTT
The P client is operated, and in this HTTP client, the user determines the position of the data on the server.
It is input by an instruction format called a URL for designating a position where data is held. This makes HT
The TP client issues an information transfer request to the server in response to the input.

Further, the HTTP protocol has a GET command which is a command for requesting data and a HEAD command which is a command for requesting related information regarding the data, and the data to be acquired is obtained by this HEAD command. It is a general practice to determine what kind of data it is in advance, then acquire that data by a GET command, and perform processing based on the acquired data.

The related information that can be obtained by this HEAD command includes the information such as the size and update date and time of the data, as well as the format information of the data.
The format information of this data is called "Content-type". According to this, for example, an extension such as “text / html” for data described in HTML, “image / gif” for GIF image data, and “image / jpeg” for JPEG image data is added. Therefore, it is possible to determine what kind of data it is from this extension.

Now, for example, the host name of the server 7 is "ho
In st.co.jp ”, if the position of the data you want to acquire on that server is“ /pub/image.GIF ”, you can use“ http: // hos
By inputting the URL "t.co.jp/pub/image.GIF", the HTTP client will enter the server "host.c."
For "o.jp", HE for "/pub/image.GIF"
Issue an AD command.

The server 7 which has received this message, "/ pub / ima
ge.GIF ”data format information, the HEAD
The HT that issued the HEAD command in response to the command
Send to TP client.

HT receiving the reply of this HEAD command
The TP client then issues a GET command for "/pub/image.GIF" to the server "host.co.jp".

Server 7 receiving this GET command
Sends the data “/pub/image.GIF” to the HTTP client that issued the GET command in response to the GET command.

In this way, H which receives the reply of the GET command
The TTP client can receive the data of the format information “/pub/image.GIF” received as a reply to the HEAD command, and can process the received data in this way.

In this way, the HTTP client
Based on the URL input from the operation unit 6, the specified data stored in the specified server 7 can be acquired together with the related information of the data. The flow of this process will be described later with reference to the flowchart of FIG.

Next, the configuration of the image processing unit 4 of this embodiment will be described.

FIG. 2 is a block diagram showing the configuration of the image processing unit 4 of this embodiment.

In the figure, reference numeral 8 denotes a DMA data transfer circuit, which controls the DMA transfer of image data from the image memory 2 to the image processing section 4. A LOG conversion circuit 9 converts RGB image data into CMY image data. A UCR circuit 10 performs UCR processing on CMY image data to generate CMYK image data 40. Reference numeral 11 is a PWM (pulse width modulation) circuit, which is CMY
The laser drive signal 42 for controlling the lighting of the laser is generated from the K image data.

Reference numeral 33 is an R data signal which means the red component data of the image data, 34 is a G data signal which means the green component data of the image data, and 35 is a B data signal which means the blue component data of the image data. , 36 are C data signals that mean the data of the cyan color component of the image data, 3
7 is M which means the data of the magenta color component of the image data
A data signal, 38 is a Y data signal which means the data of the yellow component of the image data, and 39 is a color selection signal for selecting the color for forming an image. Reference numeral 40 is a data signal selected from the CMYK data, 41 is a clock signal which is a reference synchronization signal for performing PWM processing, and 42 is a laser drive signal which controls the lighting of the laser.

The DMA data transfer circuit 8 is the system bus 3
0, and is controlled by the CPU 101 that controls the entire image forming apparatus 1 via the system bus 30. Under the control of the DMA data transfer circuit 8, when the image data held in the image memory 2 is transferred to the image processing unit 4 by DMA transfer, first, the CPU 101 requests the DMA data transfer circuit 8 to perform R, The address of the image memory 2 in which each of the G and B image data is held, and the data size for DMA transfer are set. Thereafter, the DMA data transfer circuit 8 sequentially reads the R, G, and B data from the address designated in the image memory 2 by the DMA in synchronization with the operation of the printer 5, and the read data is read by the LOG conversion circuit 9. To the R data signal 33, G data signal 34, and B data signal 35. The RGB data is output to the LOG conversion circuit 9 in synchronization with three R, G, and B data.
That is, the R, G, B data of each pixel of the image data are simultaneously output.

The R input to the LOG conversion circuit 9 in this way
Data signal 33, G data signal 34 and B data signal 3
5, the C data signal 36, the M data signal 37, and the Y data signal 38 are generated and output by the LOG operation. At this stage, the brightness data of the R, G, B data is converted into the density data of the C, M, Y data.

The C data signal 36, M data signal 37, and Y data signal 38 output from the LOG conversion circuit 9 are input to the UCR circuit 10. The UCR circuit 10 extracts the black component, which is the common part, from the C, M, and Y data and outputs it. The extraction of the black component is performed by determining the color having the minimum value of each data of C, M, and Y for each pixel and integrating the minimum value and a preset coefficient to obtain the data for the black toner. By determining the value of the K data to be obtained and subtracting the value of the K data from each of the C, M, and Y data, the value of each of the C, M, and Y data actually used for image formation is calculated. It is realized by

For example, when the coefficient for generating the data for black toner is 80% and C = 20, M = 90, and Y = 100, the minimum value is "20", Image data such as is generated.

C ': 4 (C-K) M ': 74 (M-K) Y ': 84 (Y-K) K: 16 (20 × 80% = 16)

A color selection signal signal 39 is input to the UCR circuit 10, which is used by the printer 5 for C, M,
This is a signal necessary for adopting an image forming method in which Y and K are sequentially image-formed one color at a time, and which of C ', Y', M ', and K is used at the time of image formation of C, M, Y, and K respectively. This is a signal for selecting whether to output image data.

In response to the input from the color selection signal signal 39, any one of the data signal 40 of C ', Y', M ', and K.
Is output as.

The data signal 40 output from the UCR circuit 10 is pulse width modulated in the PWM circuit 11 by the clock signal 41 which is a triangular wave. By this pulse width modulation, the data signal 40 input as, for example, 8-bit data is synchronized with the clock signal 41 and converted into a pulse wave having a pulse width corresponding to the value of the data signal 40. Is modulated. Further, in the PWM circuit 11, the input clock signal 41 is divided into two, for example, and PWM is performed at a frequency of 1/2 of the clock signal 41.
It is also possible to set to do.

By the color selection signal 39, C ', Y',
In response to the output of either the image data signal 40 of M ′ or K, the image data signal is data-corrected by a look-up table (hereinafter referred to as LUT) 302 and then sent to an integrator 301 for correction. Later image data is accumulator 30
1 is added up. The integrator 301 performs the integration corresponding to the toner color, and the CPU 101 reads the integration result and stores it in the memory 102. The CPU 101 reads out the accumulated result stored for each toner color from the memory 102, and immediately uses it as the toner consumption amount prediction data, the CP of the printer 5.
Notify U202.

The LUT 302 is composed of a random access memory rewritable by the CPU 101, and stores correction data for correcting image data according to printer characteristics for each toner color. For example, an image in which resolution is important is PWM-modulated at the cycle of the clock signal 41, but an image in which importance is attached to gradation reproducibility is PWM-modulated at a frequency half that of the clock signal 41. Even if there is, there is a slight difference in the toner consumption amount. Therefore, correction data that allows the correct toner consumption amount to be integrated is stored in the LUT 302, and which PWM is used.
The contents of the LUT 302 are rewritten depending on whether to print in the modulation mode. Alternatively, both correction data may be stored and the LU may be changed according to the PWM modulation mode.
CPU1 to switch the correction data in T302
The upper address of 01 to LUT 302 may be controlled.

Next, the configuration of the printer 5 of this embodiment will be described.

FIG. 3 is a block diagram showing the configuration of the printer 5 of this embodiment.

In the figure, reference numeral 12 is a semiconductor laser which outputs laser light in response to an input signal. A polygon mirror 13 has a regular hexagonal side surface that is mirror-finished and rotates according to the driving of the polygon motor 14. A photosensitive drum 15 forms a latent image with a laser beam, and a toner image is formed by electrostatically attracting the toner of the developing device to the latent image. A revolver 16 holds the toner cartridges for C, M, Y, and K, and rotates according to the color to be developed. 17 is a C (cyan) toner cartridge, 18 is M
A (magenta) toner cartridge, 19 is a Y (yellow) toner cartridge, and 20 is a K (black) toner cartridge.

Toner cartridges 17, 18, 19, 2
Each of Nos. 0 is configured to include a toner bottle containing a toner and a developing device containing a two-component developer including a magnetic carrier and toner. In the developing process step for each toner color, the sleeve of the developing device rotates and the electrostatic latent image is developed with the toner from the developer on the sleeve, and a predetermined amount of toner is supplied from the toner bottle into the developing device. By doing so, the developer toner concentration of the developing device in the toner cartridge is kept substantially constant.

Reference numeral 21 denotes a transfer drum which adsorbs the paper and transfers the toner on the photosensitive drum 15 onto the paper. Reference numeral 22 is a fixing drum for fixing the toner onto the paper, 23 is a paper feed cassette for holding the paper and feeding the paper at the time of image formation, 42 is a laser drive signal, 43 is a laser beam emitted from the semiconductor laser 12, and 44 is a laser beam. Is a paper transport path.

The printer 5 is a printer for forming an image by an electrophotographic method, and forms an image on a sheet with four color toners of C (cyan), M (magenta), Y (yellow) and K (black). To form. When forming an image, first, the sheets stacked in the sheet feeding cassette 23 are fed, and the sheets are conveyed through the sheet conveying path 44,
It is attracted to the transfer drum 21 and sticks to the surface of the transfer drum 21. The transfer drum 21 rotates at a constant speed, and the paper also moves according to the rotation of the transfer drum 21.

On the other hand, when printing is performed by the printer 5, the laser drive signal 42 is supplied from the image processing section 4. The supplied laser drive signal 42 is any one of the C, M, Y, and K data signals PWMed by the PWM circuit 11, and the C data signal is input first. When this data signal is ON, the laser light source of the laser 12 emits light and the laser beam 43 is output. The laser beam 43 thus output is applied to the polygon mirror 13. The polygon mirror 13 is the polygon motor 1
The laser beam 43 is scanned from one end to the other end of the photosensitive drum 15 by this rotation. This one scan becomes one scan line in image formation. A latent image is formed on the photosensitive drum 15 by the scanning of the laser light. This latent image is a latent image having electrical characteristics that a portion irradiated with laser light has a high electric potential and a portion that does not have a low electric potential.

The latent image formed on the photosensitive drum 15 in this manner is first in a portion where the C toner developing sleeve in the C toner cartridge 17 previously arranged in a portion where the revolver 16 and the photosensitive drum 15 are in contact with the photosensitive drum 15. , The negatively charged cyan toner stored in the developer coated on the sleeve contacts. This cyan toner is attracted and developed only by the portion of the photosensitive drum irradiated with the laser beam by an electric attraction force. Then, the portion of the photosensitive drum 15 on which the toner is adsorbed moves to the portion in contact with the transfer drum 21 due to the rotation of the photosensitive drum 15. At the portion where the transfer drum 21 and the photosensitive drum 15 are in contact with each other, the toner attracted to the photosensitive drum 15 is transferred onto the sheet attracted to the transfer drum 21. Next, the revolver 16 is rotated a quarter turn so that the M toner cartridge 18 comes into contact with the photosensitive drum 15, and the M data signal is input as the laser drive signal 42. The toner image is transferred.

Similarly, development with Y and K toners is performed, and toner images of C, M, Y, and K colors are transferred onto the sheet adsorbed on the transfer drum 21.

After that, the sheet is separated from the transfer drum 21 and passes between the two fixing devices 22 through the sheet conveying path 44. At this time, the fixing device 22 heats and pressurizes,
The toner transferred onto the paper is fixed on the paper and is discharged to the outside of the printer 5.

Printing is executed by the above operation.

Since the toner in the developing device is consumed when the printing operation is performed by the printer 5 as described above, particularly in the two-component developing system including the toner and the magnetic carrier, the toner density is maintained at an appropriate level. As described above, it is necessary to perform toner replenishment control for replenishing the appropriately consumed toner into the developing device.

Therefore, the CPU 1
01 to the CPU 202 of the printer 5 based on the toner consumption amount prediction information for each toner color
02, C, M, Y, K toner cartridge 1
Toner replenishment is controlled from the toner bottles 7, 18, 19 and 20 into the developing devices for the respective toner colors.

In the present embodiment, the printer engine configuration having the transfer drum 21 has been described, but four color toner images are sequentially superposed on an intermediate transfer member such as an intermediate transfer drum or an intermediate transfer belt instead of the transfer drum. After that,
It may be in the form of an engine that performs batch transfer on the conveyed paper.

Next, the processing operation of the image forming apparatus 1 of the present embodiment will be described with reference to the flowchart of FIG.

FIG. 4 shows the image forming apparatus of the present embodiment, which is C
In the flowchart showing the control processing executed by the PU 101, the program for executing this processing is the memory 102.
Remembered in.

The image forming apparatus 1 has an operating section 6, which is provided with buttons and a display and is used by the user to operate the image forming apparatus 1. In the operation unit 6, the user designates the place where the data to be printed exists by the URL. The image forming apparatus 1 waits for input until this input is made (step S
1). When the URL is input in step S1, the process proceeds to step S2, the structure of the input URL is analyzed, and the address of the server holding the desired data and the position of the data to be acquired in the server are determined. Identify. In this embodiment, it is assumed that the server 7 has data to be acquired.

Then, in step S3, a HEAD command for the data to be acquired is issued to the server 7. This HEAD command is
It is transmitted to the server 7 via the interface 3 and the network 32.

Server 7 that received this HEAD command
HEAD based on the information about the specified data.
Format information for the command is generated and transmitted to the image forming apparatus 1 via the network 32 and the network interface 3. This results in step S4
Then, when the format information from the server 7 is received, the process proceeds to step S5, and the "Content-type" information is extracted from the format information from the server 7 and stored.

Next, in step S6, a GET command for the data to be acquired is issued to the server 7. This GET command is issued to the server 7 via the network interface 3 and the network 32.

As a result, in the server 7, the data specified by the GET command is transferred to the image forming apparatus 1 via the network 32 and the network interface 3.
Send to.

When the reply from the server 7 is thus received, the process proceeds from step S7 to step S8, and image data is generated in the image memory 2 based on the data received from the server 7. Next, the process proceeds to step S9. If the "Content-type" stored in step S5 is a JPEG image, the process proceeds to step S10. If not, step S1.
Go to 2. In step S10, the image processing unit 4 is set for image processing for JPEG images. That is, U
The CR circuit 10 is set to UCR 80%, and the PWM circuit 11 is set to perform PWM at a frequency of 1/2.

The correction data of the LUT 302 is 1/2
The correction data for PWM modulation at the frequency is stored.

On the other hand, if the JPEG format is not selected in step S9, the flow advances to step S12 to set the GIF image in the image processing unit 4. That is, the UCR circuit 10 is set to UCR 100%, and the PWM circuit 1
1 is set to perform PWM at the same frequency as the clock signal 41.

As the correction data of the LUT 302, the correction data for PWM modulation at the same frequency of the clock signal 41 is stored.

After the image processing and the PWM are executed in step S10 or step S12, the image processing and PW are performed by the printer 5 in step S11.
Image formation is executed based on the M-processed image data.

Further, depending on whether the image is a JPEG image or a GIF image, an image is formed at a resolution suitable for each, and in step S13, the image data corrected by the correction data corresponding to each resolution is added by the integrator. Three
03, and the printer 5 is notified of the result of the integration as toner consumption amount prediction information.

When copying a document image, the operation unit 6 is used to specify the gradation priority mode or the resolution priority mode,
The CPU 101 may set whether the image processing and PWM modulation mode is the gradation priority mode or the resolution priority mode according to the mode designated from the operation unit 6.

As described above, image formation can be performed based on the image data stored in the server 7 designated by the operation unit 6.

According to this processing, the JPEG image is UCR
Since the black component is extracted at 80%, it is possible to generate an image excellent in gradation connection of an image that transitions from black to another color, and perform PWM at 1/2 frequency. Therefore, it is possible to generate an image having excellent gradation.

Regarding the GIF image, UCR100
%, The black component is extracted, so a light gray image is formed only with black toner, which is a problem in the image generated by combining C, M, Y, and K. Gray is not pure gray. It is possible to avoid the situation of being lost.

Further, the PWM is the clock signal 4 supplied.
Since the frequency is the same as 1, it is possible to form a high resolution image in which jaggies are not noticeable.

As described above, according to the first embodiment, a JPEG image is formed by image processing suitable for printing a natural image such as a photograph, and a GIF image is used for printing an illustration or the like. An image is formed by suitable image processing.

As a result, according to the first embodiment, the following effects can be obtained.

Since the storage position of the data to be acquired is designated by the operation unit 6 of the image forming apparatus 1, the image processing and the image forming processing can be performed only by the image forming apparatus 1, and no other client apparatus is required. It is possible to perform appropriate image processing and appropriate toner consumption amount prediction according to the type of image data to be acquired. The communication software can be simplified because the storage position of the acquired data is specified in the operation unit 6 of the image forming apparatus 1, and the software can be easily developed. -The server inquires the "Contents-type" and determines the image format based on the result, so that it can be printed normally even if there is no URL extension. Then, the image processing unit 4 performs optimum image processing on the image data, integrates the image data, and predicts an appropriate toner consumption amount of each toner color,
Since the notification is sent to the printer 5, the printer 5 can perform toner supply control accordingly. Therefore, the printer 5 does not need to be provided with a circuit for predicting toner consumption.

<Second Embodiment> In the second embodiment, desired data is acquired by the HTTP protocol based on the URL input by another device connected to the network 30, and the acquired data is acquired. An image forming apparatus that generates image data based on the image forming apparatus will be described.

In the second embodiment, the positional information in which the data to be acquired is stored is input as the URL from the client device 24 connected to the network 30,
The input URL information is transmitted to the image forming apparatus 1, and the image forming apparatus 1 receiving the information acquires data from the server 7 and forms an image.

FIG. 5 is a block diagram showing the overall configuration of a network system including the image forming apparatus 1 according to the second embodiment of the present invention. The parts common to those in FIG. Omit it.

In FIG. 5, reference numeral 24 denotes a client device, which has a function of designating data that the image forming apparatus 1 acquires and forms an image. Reference numeral 4a is an image processing unit, which basically performs substantially the same function as the image processing unit 4 described above,
The configuration will be described later with reference to FIG. Reference numeral 5a is a printer engine (hereinafter, simply referred to as a printer), the details of which will be described in detail with reference to FIG.

FIG. 6 shows the image processing unit 4a according to the second embodiment.
2 is a block diagram showing the configuration of FIG. 2 and the same parts as those in FIG.

Note that, for example, the CPU 101, the image memory 2, the network interface 3, the image processing unit 4a, and the memory 102 described above function as an image control unit and can be mounted as an image processing board.

In FIG. 6, reference numeral 8 is a DMA data transfer circuit for controlling the DMA transfer of image data from the image memory 2.
Reference numeral 25 is a gamma conversion circuit that performs gamma conversion, and 26 is a binarization circuit that binarizes the input image data to generate binary data. Reference numeral 45 is an R data signal which means the red component data of the image data, 46 is a G data signal which means the green component data of the image data, 47 is a B data signal which means the blue component data of the image data, and 48 is R data signal converted by the gamma conversion circuit 25, 4
Reference numeral 9 is a G data signal converted by the gamma conversion circuit 25, and 50 is a B data signal converted by the gamma conversion circuit 25. Reference numeral 39 is a color selection signal for selecting a color for forming an image, 51 is a binarization method selection signal for selecting a binarization method in the binarization circuit 26, and 52 is LE.
This is an LED drive signal for controlling the lighting of the D array. Reference numeral 303 is an integrator that integrates the LED drive signal 52.

The DMA data transfer circuit 8 is connected to the system bus 30 and is controlled by the CPU 101 which controls the entire image forming apparatus 1 via the system bus 30. The image data held in the image memory 2 by the DMA transfer by the DMA data transfer circuit 8 is transferred to the image processing unit 4
When transferring to a, DM is first executed by the CPU 101.
For the A data transfer circuit 8, the address of the image memory 2 in which the R, G, and B image data are held and the data size to be transferred are set. After that, the DMA data transfer circuit 8 causes the printer 5a to print. In sync with the movement,
The R, G, and B image data are sequentially read from the image memory 2 by DMA, and the read data are output to the gamma conversion circuit 25 as an R data signal 45, a G data signal 46, and a B data signal 47. This output is performed in synchronization with R, G, B data. That is, the R, G, B data of each pixel are simultaneously output.

The R data signal 45, G data signal 46, and B data signal 4 thus input to the gamma conversion circuit 25.
7 is gamma-converted based on a preset gamma conversion table, and R data signal 45 to R data signal 4
8, G data signal 46 to G data signal 49, and B data signal 47 to B data signal 50 are generated and output. R output from these gamma conversion circuits 25
Data signal 48, G data signal 49, B data signal 50
Is input to the binarization circuit 26. The binarization circuit 26 selects which color is output based on the color selection signal signal 39, and which binarization method is selected based on the binarization method selection signal 51. decide. In the second embodiment, the binarization circuit 26 can select either the dither method or the error diffusion method.

Here, in the dither method, based on each luminance data, the luminance data is converted into a binary pattern based on a binarized pattern that expresses a density corresponding to the luminance as an area gradation, and an image is formed. This is a method of generating data for use. This dithering method is a binarization method suitable for printing such as illustrations, drawings, characters, etc., in which gradation transitions are small and the boundaries of regions are clear.

On the other hand, the error diffusion method is based on the error between the original data of the pixel to be binarized, the original data of the binarized peripheral pixel, and the data generated by the binarization, and the random number. Is a binarization method for binarizing the pixel,
This is a binarization method suitable for a natural image such as a natural image that has many gradation transitions.

The image data binarized in this way is the LED
The drive signal 52 is output to the printer 5a.

As the binarized image data, L
The ED drive signal 52 is also sent to the integrator 303, and the integrator 3
It is integrated with 03. The integrator 303 may be a simple up-counter because it is an area gradation based on binary data, and in that case, an integrator having a smaller circuit than in the case of PWM modulation is sufficient. Further, the image data corresponding to each toner color is integrated, and the integrated result is read by the CPU 101 and stored in the memory 102. CPU 101
Reads out the accumulated result stored for each toner color from the memory 102 and immediately notifies the CPU 202 of the printer 5a as toner consumption amount prediction data.

FIG. 7 is a block diagram showing the structure of the printer 5a according to the second embodiment. The parts common to those in FIG. 3 described above are designated by the same reference numerals.

In FIG. 7, 27 is an LED drive signal 52.
LED array in which each element emits light according to
A photosensitive drum on which a latent image is formed by turning on each element of the array, and an image is formed by adsorbing toner to the latent image,
Reference numeral 16 is a revolver which holds the C, M, Y and K toner cartridges and rotates according to the color to be developed.
17 is a C (cyan) toner cartridge, 18 is an M (magenta) toner cartridge, 19 is a Y (yellow) toner cartridge, and 20 is a K (black) toner cartridge. Each cartridge has a configuration including a toner bottle and a developing device, as in the first embodiment. 21
Is a transfer drum for adsorbing the sheet and transferring the toner of the photosensitive drum 15 onto the sheet, 22 is a fixing drum for fixing the toner onto the sheet, 23 is a sheet holding the sheet, and the sheet is fed at the time of image formation. Paper cassette, 52 is LED drive signal, 4
Reference numeral 4 is a sheet conveyance path.

The printer 5a is a printer for forming an image by an electrophotographic method, and a color image is formed on a sheet by four color toners of C (cyan), M (magenta), Y (yellow) and K (black). To form. The image is developed using an LED array, which is different from the laser system described above.

When forming an image, first the paper feed cassette 2
The sheets stacked in 3 are fed, and the sheets are conveyed in the sheet conveyance path 4
4 is conveyed, adsorbed by the transfer drum 21 and stuck to the surface of the transfer drum 21. The transfer drum 21 rotates at a constant speed, and the paper also moves according to the rotation of the transfer drum 21. When printing with the printer 5a, LE
The D drive signal 52 is supplied from the image processing unit 4. The supplied LED drive signal 52 is an image signal of any one of C, M, Y, and K generated by the binarization processing of the binarization circuit 26, and the image signal of C is first input.

In the LED array 12, LEDs corresponding to the lateral width of the photosensitive drum 15 are linearly arranged and one LED is arranged.
ED has a size corresponding to the width of one pixel. When the LED drive signal 52 supplies the image data for one scanning line to be developed, the latent image formation for one scanning line is performed by the light emission of the LED. LE of the part where the LED drive signal 52 is on
D is lit and the potential of the photosensitive drum 15 is high, and the other portion is not lit and the potential of the photosensitive drum 15 is lowered to form a latent image.

The latent image thus formed on the photosensitive drum 15 is first stored in the C toner cartridge 17 at a portion where the C toner cartridge 17 and the photosensitive drum 15 which are previously arranged in a portion where the revolver 16 and the photosensitive drum 15 are in contact with each other. The negatively charged cyan toner stored in the developer coated on the developing sleeve of the developing device comes into contact with the developing device. The cyan toner is attracted and developed only by the laser-irradiated portion of the photosensitive drum by an electric attraction force. The portion of the photosensitive drum 15 to which the toner is adsorbed moves to the portion in contact with the transfer drum 21 due to the rotation of the photosensitive drum 15. At the portion where the transfer drum 21 and the photosensitive drum 15 are in contact with each other, the toner attracted to the photosensitive drum 15 is transferred onto the sheet attracted to the transfer drum 21.

Thereafter, the revolver 16 is moved to 1 / A of the entire circumference so that the M toner cartridge 18 contacts the photosensitive drum 15.
It is rotated by 4. Then, the M image signal is input to the laser drive signal 42, and the magenta toner is transferred onto the sheet in the same manner as the C development. When developing each color, the color selection signal 39 indicates that when developing C, the image data of C is LE.
It is set to output to the D drive signal 52, and M, Y,
When developing K, the image data of M, Y and K are LE
It is set to be output to the D drive signal 52. Similarly, Y, K development is also performed, and the toners of C, M, Y, K colors are transferred onto the sheet adsorbed on the transfer drum 21.

After that, the sheet is separated from the transfer drum 21 and passes between the two fixing devices 22 through the sheet conveying path 44. At this time, the fixing device 22 heats and pressurizes,
The toner image transferred onto the paper is fixed on the paper and is discharged to the outside of the printer 5a.

Printing is executed in this manner.

FIG. 8 shows the image forming apparatus 1 according to the second embodiment.
In the flow chart showing the processing in step 1, the control program for executing this processing is stored in the memory 102.

Since the toner in the developing device is consumed when the above-described printing operation is performed by the printer 5, in the two-component developing system including the toner and the magnetic carrier,
It is necessary to perform toner replenishment control for replenishing the appropriately consumed toner to the developing device so as to maintain an appropriate toner concentration.

Therefore, in accordance with the printing operation, the CPU 1
01 to the CPU 202 of the printer 5a, based on the toner consumption amount prediction information for each toner color, the CPU
202, C, M, Y, K toner cartridge 1
Toner replenishment control is performed from the toner bottles 7, 18, 19, and 20 into the developing devices for the respective toner colors.

As shown in FIG. 5, the image forming apparatus 1 according to the second embodiment is connected to the client device 24 via the network 32. This client device 24
Is a data processing device capable of inputting a character string by a user such as a personal computer. In this client device 24, the user inputs data instructing the data to be printed by the image forming apparatus 1. The format of this data is the URL in the first embodiment described above.
And

The user of the client device 24 uses this U
After inputting the RL, the input URL is transmitted to the image forming apparatus 1 via the network 30. The URL sent in this way is
It is received by the image forming apparatus 1 via the interface 3. The image forming apparatus 1 waits for input until this input is made (step S21). Step S21
When the URL is input, the process proceeds to step S22, the structure of the input URL is analyzed, and the address of the server holding the desired data and the position of the data to be acquired in the server are specified. . In the second embodiment,
It is assumed that the server 7 has data to be acquired.

Then, in step S23, the GET command for the data to be acquired is issued to the server 7. This GET command is issued to the server 7 via the network interface 3 and the network 32.

As a result, in the server 7, the data specified by the GET command is transferred to the image forming apparatus 1 via the network 32 and the network interface 3.
Send to.

When the reply from the server 7 is thus received, the process proceeds from step S24 to step S25, and the image data is generated in the image memory 2 based on the data received from the server 7. Then, the process proceeds to step S26 and step S
The extension of the URL analyzed in 22 is ".JPG" or ".j"
It is determined whether the image is a JPEG image such as "peg".
When the image is a JPEG image, the process proceeds to step S27, and image processing for the JPEG image is set in the image processing unit 4a. That is, the gamma conversion circuit 9 sets the gamma table for the natural image, and the binarization circuit 10 sets the binarization method by the error diffusion method.

On the other hand, if the JPEG format is not selected in step S26, the process proceeds to step S29, and the image processing unit 4
The setting for GIF image is performed for a. That is, the gamma conversion circuit 9 sets the gamma conversion table for illustration, and the binarization circuit 10 sets the binarization method by the dither method. Thus, step S27 or step S
After the image processing and the binarization processing are performed by 29, the process proceeds to step S28, and the printer 5a executes the image formation based on the image data subjected to the image processing and the binarization processing.

Furthermore, for the JPEG image, the error diffusion method,
The image data obtained by binarizing the GIF image by the dither method is added to the accumulator 303 for each toner color in step S30.
And the printer 5 is notified of the result of the integration as toner consumption amount prediction information.

In this way, the process of forming an image based on the data stored on the server 7 designated by the client device 24 is completed.

According to this processing, the JPEG image is subjected to gamma conversion for a natural image and further binarized by the error diffusion method, so that an image is formed with a tint and binarization suitable for a natural image. It is possible.

Further, the gamma conversion for the illustration is performed on the GIF image and further binarized by the dither method, so that the image can be formed with the tint and binarization suitable for the illustration. is there.

It should be noted that in both cases, integrating binary data is equivalent to integrating the number of dots. Therefore, since the toner consumption amount is approximately calculated as being proportional to the number of dots, the integrating circuit can be simplified.

As described above, according to the second embodiment, the JPEG image is formed by performing image processing suitable for printing a natural image such as a photograph, and the GIF image is printed with an illustration or the like. Image processing suitable for performing is performed to form an image. Even in the area gradation method, the toner consumption information is notified to the printer 5a, and the printer 5a is notified.
Can perform appropriate toner supply control.

According to the second embodiment, the following effects can be obtained.

The address where desired data is stored can be designated in the client device, and the operation unit or the like for designating the address in the image forming apparatus 1 becomes unnecessary, and the cost can be reduced. -It is possible to perform appropriate binarization processing according to the type of image.・ Because the image type is determined by the URL extension,
It is also applicable to protocols other than the HTTP protocol.

In the above description, the first and second embodiments have been described independently, but the present invention is not limited to this. For example, the program 5 of the second embodiment is described.
a may be adopted in the first embodiment. Further, the image processing unit 4 of the first embodiment may further include the function of the image processing unit 4a of the second embodiment, and both of the image processing units 4 and 4a are the same as the images shown in FIGS. Not all of the processing functions but only some of them may be provided.

In the first embodiment, the type of image data is discriminated based on the format information from the server. Instead, as described in the second embodiment,
The type of image data may be determined based on the extension of the URL.

In the image processing unit of the first embodiment, the UR
When the type of image is determined by the extension of L, for example, it is possible to appropriately select gradation priority or resolution priority by switching the image processing to an appropriate one depending on whether it is a JPEG image or a GIF image. Is. For example, if it is determined that the image is a JPEG image with the URL extension, gradation priority processing is selected, PWM modulation with a frequency half that of the clock signal is performed, and image data is also integrated with correction data for gradation priority. Selected by LUT 302, integrator 30
1 is added, and the result of the addition is notified to the printer 5. If it is determined that the image is a GIF image, resolution priority processing is selected, PWM modulation is performed at the cycle of the clock signal, and correction data with resolution priority is also selected by the LUT 302 and integrated by the integrator 301. The printer 5 is notified of the result.

As described above, since the appropriate image processing is selected and the image data integration processing is appropriately corrected depending on the extension of the URL, the toner consumption amount is predicted well and the printer 5 Can maintain an appropriate toner concentration.

According to the first and second embodiments described above,
Since the image processing unit is configured to predict the toner consumption amount from the image data and notify the printer, the toner replenishment control of the printer can be made substantially the same regardless of the configuration of the image forming unit. Therefore, for example, even if the image forming apparatus has a configuration in which various image processing boards are connected to the printer, there is an advantage that the control of the printer does not need to be significantly changed.

As described above, even if the costs, functions, and the like desired by the user are realized by connecting various image processing boards to the printer, it is advantageous in that no new cost increase is caused in the printer. is there. Further, since the printers can be designed in common, there is an advantage that the development period of the printer can be shortened and the printer can be easily shared.

Further, there is an advantage that suitable toner replenishment control can be performed even if there are various combinations of various image data from the network and the image forming apparatus for printing.

[0136]

Other Embodiments Although the embodiments of the present invention have been described in detail above, the present invention can be applied to a system including a plurality of devices (eg, host computer, interface device, reader, printer, etc.). It may be applied to an apparatus (for example, a copying machine, a facsimile apparatus, etc.) which is composed of one device.

The present invention is a software program (FIG. 4 or FIG. 8) for realizing the functions of the above-described embodiments.
The program corresponding to the flowchart shown in 1) is directly or remotely supplied to the system or apparatus, and the computer of the system or apparatus reads and executes the supplied program.

Therefore, the program code itself installed in a computer to implement the functional processing of the present invention by the computer also implements the present invention. That is, the claims of the present invention include the computer program itself for realizing the functional processing of the present invention.

In this case, the program may take any form such as an object code, a program executed by an interpreter, or script data supplied to an OS as long as it has the function of the program.

As a storage medium for supplying the program, for example, a floppy (registered trademark) disk, an optical disk (CD-ROM, CD-R, CD-RW, DVD, etc.), a magneto-optical disk, a magnetic tape, a memory card Etc.

In addition, as a program supply method,
A mode in which the program of the present invention is acquired by file transfer via the Internet is also included.

Further, the program of the present invention is encrypted to be a CD.
-Stored in a storage medium such as a ROM and distributed to users, users who have met prescribed conditions are allowed to acquire key information for decryption via the Internet, and the key information is used for encryption. It is also possible to execute the program and install the program on a computer to realize it.

The computer executes the read program to realize the functions of the above-described embodiments, and the OS or the like running on the computer executes the actual processing based on the instructions of the program. The functions of the above-described embodiments may be realized by performing a part or all of the processing.

Furthermore, after the program read from the storage medium is written in the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, based on the instructions of the program,
CPU provided on the function expansion board or function expansion unit
Etc. perform a part or all of the actual processing, and the functions of the above-described embodiments are also realized by the processing.

[0145]

According to the present invention, it is possible to realize an image forming apparatus that does not need to generate information necessary for toner replenishment control on the printer engine side, so that the printer engine can be provided at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a system including an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an image processing unit according to the first embodiment.

FIG. 3 is a block diagram showing the configuration of the printer according to the first embodiment.

FIG. 4 is a flowchart illustrating processing in the image forming apparatus according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing a system configuration including an image forming apparatus according to a second embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of an image processing unit according to the second embodiment.

FIG. 7 is a block diagram showing the configuration of the printer according to the second embodiment.

FIG. 8 is a flowchart illustrating processing in the image forming apparatus according to the second embodiment.

Claims (8)

[Claims] 1. An image forming unit that includes a developing device that contains a developer, forms an image on a recording medium based on supplied data, and control unit that controls the supply of image data to the image forming unit. An image forming apparatus comprising: a control unit configured to generate predictive data of a developer consumption amount with respect to input image data; and a supply unit configured to supply the generated predictive data to the image forming unit. An image forming apparatus, comprising: a means for controlling the supply of the developer to the developing device based on the supplied prediction data. 2. The image forming apparatus according to claim 1, wherein the control unit further includes an image processing unit that performs image processing according to the type of image data and outputs the image processing to the prediction unit. 3. The predicting means comprises an integrating means for integrating the image data that has been subjected to the image processing, and the result of the integrating is used as the predictive data. Image forming device. 4. The predicting means further comprises a correcting means for correcting the image data subjected to the image processing by using correction data according to the contents of the image processing. The image forming apparatus according to item 3. 5. An image forming means for forming an image on a recording medium based on the supplied data, comprising a developing device containing a developer, and a control means for controlling the supply of the image data to the image forming means. A method of controlling an image forming apparatus, comprising: a controlling step of generating predictive data of a developer consumption amount with respect to input image data; and the predictive data generated to the image forming means. A supply step of supplying, wherein the image forming unit includes a replenishment control step of controlling replenishment of the developer to the developing device based on the predicted data supplied. Control method. 6. The method of controlling an image forming apparatus according to claim 5, wherein the control unit further includes an image processing step of performing image processing according to the type of image data. 7. The predicting step includes an integrating step of integrating the image data subjected to the image processing,
The method of controlling an image forming apparatus according to claim 5, wherein the result of the integration is used as the prediction data. 8. The method according to claim 6, wherein the predicting step further includes a correcting step of correcting the image data subjected to the image processing by using correction data according to the content of the image processing. 7. The control method of the image forming apparatus according to 7.