JPH1191206A - Image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To output effectively a high quality image by a method wherein various kinds of information, data, etc., are enabled to be transferred mutually between a host computer and an image forming device. SOLUTION: An image forming system is so constituted that delivery of information between a host computer 1 and a printer 2 can be executed 10 both directions. The host computer side 1 controls whether or not printer characteristics information or dither matrix information suitable for the printer device 2 is received from the printer device 2 before start of printing, and when not received, requests the information from the printer device 2. The printer side 2, when a request concerning characteristic information inherent to the printer device or dither matrix information is received, transfers the information related to the request to the host computer side 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a printer, a facsimile machine, or a multifunction machine including the above-described apparatus including a copying machine, and includes a computer and an image forming apparatus connected to the computer for forming an image. The present invention relates to an image forming system comprising:

[0002]

2. Description of the Related Art Conventionally, printers have been widely used as image forming apparatuses capable of receiving an image signal from an external device such as a host computer and outputting the image.

In the above-described printer device, when a multi-valued image composed of a photograph or a halftone figure is subjected to dither processing to output an image as a binary image expressed in gradation, the printer device usually has different printing characteristics. There is no means for changing the gradation expression method or the correction value so as to correspond to each of the above, and the same binary image data has been sent to any type of printer. However, in recent printer devices such as laser printers, high resolution has progressed, and especially when a fine halftone is expressed, the output does not become constant depending on the pattern or the halftone density. Differences in output due to characteristics have become noticeable.

Therefore, various techniques for improving the quality of an output image in such a printer have been proposed and implemented.

For example, Japanese Patent Application Laid-Open No. 1-204744 discloses that a data identification signal can be received together with multi-valued image data from a host computer or the like, and different processing is performed on the multi-valued image data by the data identification signal. By doing
A printer device in which different image qualities are made constant for printer devices having different specifications is described.

Japanese Unexamined Patent Publication No. Hei 8-18787 discloses a multi-value dither matrix which includes a gamma correction table having a plurality of density correction curves corresponding to the gamma characteristics of each dot of the multi-value dither matrix. An image forming apparatus capable of selecting and correcting a correction curve is described.

[0007]

In the printer having the above-mentioned conventional configuration, the printer described in Japanese Patent Application Laid-Open No. 1-204744 receives information such as image data sent from a host computer and sends it to the printer. In such a case, an optimum image output corresponding to the type of image data is performed, and it is necessary to provide characteristic information of a printer connected to the host computer.

In the image forming apparatus described in Japanese Patent Application Laid-Open No. H8-18787, the relationship with the host computer is such that after the dither processing in the host computer, the image forming apparatus performs γ correction upon receiving the dither processing. .

In any case, in the above-described conventional apparatus, the host computer and the printer connected thereto perform processing independently of each other, and each independently transmits characteristic information, image data, and the like. I have it.

An object of the present invention is to provide an image forming system in which various kinds of information, data, and the like can be transferred between a host computer and an image forming apparatus so that a high-quality image is output effectively. Aim.

[0011]

In order to achieve the above object, an image forming system according to the present invention comprises: an image forming apparatus having means capable of uploading dither pattern data for reproducing halftone to a computer; And a computer having means capable of downloading dither pattern data for halftone reproduction from the image forming apparatus. With this configuration, dither processing suitable for halftone reproduction characteristics in the image forming apparatus is achieved. , It is possible to create a halftone image on the computer side and to output the image in the image forming apparatus, thereby improving the output image quality. In addition, even when a plurality of image forming apparatuses are connected, it is not necessary for the computer to have halftone characteristic information for each image forming apparatus.

Further, the image forming system of the present invention is a detecting means for detecting that a change in print characteristics due to a remaining amount of toner or ink, a use time, the number of printed sheets, or the like has occurred in the image forming apparatus. And notification means for notifying the computer of the occurrence of the change, and means capable of uploading dither pattern data suitable for image formation after the change to the computer. Since the dither pattern data can be changed following changes in the characteristics of the image forming apparatus, the optimum image quality can always be maintained.

Further, the image forming system according to the present invention has an image forming apparatus provided with means capable of uploading halftone density correction information suitable for image formation to a computer, and an image forming apparatus suitable for image forming from the image forming apparatus. And a computer having means capable of downloading halftone density correction information. With this configuration, a halftone image obtained by density correction before dither processing suitable for halftone density characteristics in the image forming apparatus can be obtained. It is possible to create the image on the computer side and output the image by the image forming apparatus, and it is possible to improve the reproducibility of the output density. In addition, even if a plurality of image forming apparatuses are connected, it is not necessary for the computer to provide the halftone density correction information for each image forming apparatus.

Further, the image forming system according to the present invention is characterized in that a detecting means for detecting that a change in print characteristics due to a remaining amount of toner or ink, a use time, the number of printed sheets, or the like has occurred in the image forming apparatus. A notification unit for notifying a computer of the occurrence of the change, and a unit capable of uploading halftone density correction information suitable for image formation after the change to the computer. According to the configuration, the halftone density correction information can be changed according to the change in the characteristics of the image forming apparatus, so that the optimum image quality can always be maintained.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a printing system for explaining an embodiment of the present invention. In this example, for simplification of description, one printer is provided for one host computer 1. 2 is connected,
A plurality of printer devices may be connected.

The print data requested by the application software 11 of the host computer 1 is transferred to a printer driver
The software 12 converts the language into a language that can be understood by the printer device 2 and sends it to the printer device 2. On the other hand, the printer control device of the printer device 2 receiving the print data
21 interprets the data contents to develop an image and transfers it to the printer engine 22 as an image signal,
The printer engine 22 forms a physical image.

FIG. 2 is a block diagram showing an electrostatic image forming apparatus as a specific example of the printer apparatus. When a video signal is input to the printer engine 22, a laser writing unit 23 uses a light emitting diode (not shown). Drive control is performed to expose the photoreceptor belt 24. Prior to this exposure, the exposed surface of the photoreceptor belt 24 is uniformly charged by the charging charger 26 after being discharged by the discharging lamp 25, so that the exposure forms an electrostatic latent image. here,
The image pattern to be exposed is a single-color image pattern when a desired full-color image is separated into yellow, magenta, cyan, and black.

The electrostatic latent images of each color thus formed are developed into yellow, magenta, cyan, and black by rotary developing units 27a, 27b, 27c, and 27d to form single-color images. The single-color images formed on the photoreceptor belt 24 are transferred to an intermediate transfer belt 30 that moves while contacting the photoreceptor belt 24, and a single-color image of yellow, magenta, cyan, and black is transferred to the surface of the intermediate transfer belt 30. Sequentially. The images of yellow, magenta, cyan, and black superimposed on the intermediate transfer belt 30 are transferred by the transfer roller 35 to the transfer paper 34 conveyed from the paper supply table 31 via the paper supply roller 32 and the registration roller 33. Is done. After the transfer, the transfer paper 34 is fixed on the image by the fixing device 36, and then is discharged to a discharge tray 37.

In FIG. 2, reference numeral 40 denotes an arithmetic processing unit which includes the printer control device 21 and controls printing operation and the like in the printer device and controls each unit of the above-mentioned components.

Next, the operation of the printing system will be described. In this printing system, information can be exchanged between the host computer 1 and the printer device 2 in both directions (download and upload).

The printer driver software 12 of the host computer 1 manages whether or not printer characteristic information or dither matrix information suitable for the printer device 2 has been received from the printer device 2 before starting printing. It has a function of requesting information from the printer device 2.

When the printer 2 receives a request for characteristic information or dither matrix information unique to the printer from the host computer 1, the printer transfers the request information to the host computer 1. The printer control device 21 includes a sensor and the like, and the remaining amount of toner in the developing devices 27a to 27d (the remaining amount of ink if the image forming apparatus is a printing device and uses ink), the total number of printed sheets, and the total printing time. And the like, which can detect a change in information that causes a change in printer characteristics. Further, the printer control device 21 has a function of notifying the host computer 1 when a change occurs in the optimum dither matrix table or the optimum density correction information based on the information that causes the printer characteristic change. I have.

FIG. 3A shows an example of a dither matrix table sent from the printer device 2 to the host computer 1. FIGS. 3B and 3C show a host computer-printer relating to transmission and reception of the information. FIG. 4 is an explanatory diagram showing an example of a data format between devices. The table in this example is an 8 × 8 matrix, and a multi-valued image of 256 gradations is 64 (= 8 × 8) at the maximum.
It can be converted to halftone of gradation. Each value in the table corresponds to one of the multivalued images, and is treated as a threshold value for determining whether each multivalued image is black or white.

From the host computer 1 to the printer 2
When the optimum dither matrix pattern request command is sent to the printer device 2, the printer device 2 receives the command and sends out the dither matrix pattern data. Here, the actual data follows immediately after the last character "D" of the command identification sequence, and each parameter is separated by a comma ",".
The first two parameters represent the vertical and horizontal matrix sizes, and the following (vertical × horizontal) parameters are threshold values in the actual table.

FIG. 4A shows an example of temperature correction information sent from the printer device 2 to the host computer 1.
FIGS. 4B and 4C are explanatory diagrams showing examples of a data format between the host computer and the printer device regarding the transfer of the information. In this example, a density correction data table is stored in the printer control device 21 of the printer device 2 based on density characteristic data when a certain data gradation density is printed as it is, and the printer device 2 When a request for temperature correction information is received from the host computer, a necessary table is sent to the host computer 1 in a predetermined format. Here, unlike the example of FIG. 3, a correction table for halftone data of 64 gradations is illustrated.

By the way, the characteristic diagram of FIG. 4A shows a characteristic in which the low density and the high density become darker and the intermediate density becomes lighter, so that the correction shows the opposite characteristic curve. It is performed based on the data table (however, the illustrated table is not suitable for the characteristic diagram).

The arithmetic processing unit 40 is provided with a detecting means for detecting the occurrence of a change in printing characteristics due to the remaining amount of toner (or ink), the usage time, the number of printed sheets, and the like. Since the dither pattern data and / or the halftone density correction can be changed following the change in the characteristics of the apparatus 2, the optimum image quality can be always maintained.

That is, as shown in FIG. 5, by using a management table of a plurality of characteristic information managed in the printer control device 21, the dither pattern and the halftone density correction can be changed in accordance with the remaining amount of toner. Is possible. Although the remaining amount of toner is used as a reference here, the table shown in FIG. 5 is expanded in two dimensions and three dimensions when considering a plurality of other characteristic change factors.

FIG. 6 is a diagram showing an example of a characteristic information change notification command sent from the printer device 2 to the host computer 1 when the optimum characteristic information changes due to a change in the characteristic change factor. When the computer 1 receives this, the task of reloading the characteristic information as shown in FIG. 3 or FIG. 4 from the printer device 2 occurs.

[0031]

As described above, according to the image forming system of the present invention, the image forming apparatus is suitable for the halftone image by the dither processing suitable for the halftone reproduction characteristic or the halftone density characteristic for the image forming apparatus. It is possible to generate a halftone image by the density correction before the dither processing on the computer side and output the image by the image forming apparatus, so that the output image quality can be improved.
In addition, even when a plurality of image forming apparatuses are connected, it is not necessary for the computer to provide halftone characteristic information for each image forming apparatus, and the configuration can be simplified.

Further, since the dither pattern data or the halftone density correction information can be changed following changes in the characteristics of the image forming apparatus, the optimum image quality can be always maintained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a printing system for describing an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a specific example of the printer device of FIG. 1;

FIG. 3A is an explanatory diagram illustrating an example of a dither matrix table sent from a printer device to a host computer according to the present embodiment. FIGS. 3B and 3C are diagrams illustrating information according to the present embodiment. Host computer for giving and receiving
FIG. 3 is an explanatory diagram illustrating an example of a data format between printer devices.

FIG. 4A is an explanatory diagram illustrating an example of temperature correction information sent from a printer device to a host computer according to the embodiment, and FIGS. 4B and 4C are information according to the embodiment; FIG. 4 is an explanatory diagram showing an example of a data format between a host computer and a printer device regarding transmission and reception of data.

FIG. 5 is an explanatory diagram of a management table of a plurality of characteristic information managed in the printer control device according to the embodiment.

FIG. 6 is an explanatory diagram showing an example of a characteristic information change notification command sent from the printer device to the host computer according to the embodiment.

[Explanation of symbols]

1: Host computer, 2: Printer device, 11:
Application software, 12 ... Printer driver
Software 21 Printer controller 22 Printer engine 23 Laser writing unit 24 Photoreceptor belt 27a-27d Developing device 30 Intermediate transfer belt 35
... Transfer roller, 36 ... Fixing device, 40 ... Calculation processing unit.

Claims (4)

[Claims] An image forming apparatus having means for uploading dither pattern data for halftone reproduction to a computer, and downloading dither pattern data for halftone reproduction from the image forming apparatus. An image forming system, comprising: a computer provided with possible means. 2. A detecting means for detecting, in the image forming apparatus, a change in print characteristics due to a remaining amount of toner or ink, a use time, the number of printed sheets, and the like, and a computer for detecting the occurrence of the change. And a means for uploading dither pattern data suitable for image formation after the change to a computer.
The image forming system as described in the above. 3. An image forming apparatus having means for uploading halftone density correction information suitable for image formation to a computer, and downloading halftone density correction information suitable for image formation from the image forming apparatus. An image forming system, comprising: a computer having means capable of performing the operation. 4. A detecting means for detecting, in the image forming apparatus, a change in print characteristics caused by a remaining amount of toner or ink, a use time, the number of printed sheets, and the like, and a computer for detecting the occurrence of the change. 4. An image forming system according to claim 3, further comprising: a notifying unit for notifying the user of the image, and a unit capable of uploading halftone density correction information suitable for image formation after the change to a computer. .