KR100301005B1 - Method for transmitting image data from computer of image print system to printer - Google Patents

Abstract

PURPOSE: A method for transmitting image data from a computer of an image print system to a printer is provided to improve print quality by referring to an operating state of a printer. CONSTITUTION: A user sends a print command by using a predetermined input device(110). A computer receives a work standby time from a printer(120). At this time, the printer generates the work standby time information as a part of state information, periodically or according to a command of the computer. The computer determines a data compressing rate for image file transmission from data capacity of a printing image file(130). An image compression file is generated according to the data compressing rate by a data compression program if the computer determines the data compressing rate(140). The image compression file is transmitted to the printer(150). The printer decompresses the image compression file and prints contents of the decompressed image file(160).

Description

Image data transfer method from computer of image printing system to printer

The present invention relates to a method of transmitting image data from a computer of an image printing system to a printer.

An image printing system has a computer and a printer connected via mutual cables or networks.

In such an image printing system, a computer transmits image file data to be printed to a printer, and the printer operates so that the original content of the received data is printed on paper.

When the printer in charge of printing is an electrophotographic method, an optical scanning device for forming an electrostatic latent image on the photosensitive medium by exposure, a developer for forming the electrostatic latent image as a developer, and an image formed with the developer are transferred from the photosensitive medium to the paper. A transfer device is provided.

Such a printer provides status information related to whether a print job is available to a user computer connected by a cable or a network. Examples of status information provided from the printer to the user's computer include a busy signal indicating that the data received in the data storage buffer is full, an empty signal indicating that there is no paper, or a paper jammed during printing. Another major problem is the fault signal, which tells you that you can't print anymore. In addition, job waiting time information corresponding to the start of the print job for the image data to be received, which is currently in the power saving mode or there are many waiting jobs, is informed to the computer as status information.

On the other hand, as part of reducing the time required to transfer the image source file contents to the printer, there is a method using a compression technique that can reduce the data capacity compared to the total data of the image source file, even if the image quality is slightly reduced. In general, the higher the compression rate, the lower the print quality. However, conventionally, by constantly applying the compression ratio to the image source file without considering the state of the printer, the waiting time of the print job is long enough, and the contents of the image original file are sent to the printer as it is or lower than the set compression ratio. Even if it may be a problem to drop the print quality at a constant rate.

The present invention was devised to improve the above problems, and reflects the operation of the printer, from the computer of the image printing system to the printer to determine the amount of information to be sent to the printer for the image source file to improve the print quality. Its purpose is to provide a method of transmitting image data.

1 is a block diagram showing an image printing system to which the image data transmission method according to the present invention is applied;

2 is a flowchart illustrating a method of transmitting image data according to the present invention.

<Description of Symbols for Major Parts of Drawings>

10: Computer 11: Central Processing Unit

12, 22: storage device 13, 23: input device

14, 24: display unit 17: bus

21: main controller 25: engine controller

26: printer engine 30: communication interface

In order to achieve the above object, a method of transmitting image data from a computer to a printer of an image printing system according to the present invention includes an image to be given a new print job from the printer when a print instruction is given for a predetermined image original file. Obtaining job waiting time information corresponding to the start of the print job for the data; and data to be applied when transferring the image source file to the printer from the job waiting time and the data capacity of the image source file. Determining a compression rate, generating an image compressed file corresponding to a compression rate determined from data of the image source file by a predetermined data compression program, and transmitting the image compressed file to a printer.

Hereinafter, a method of transmitting image data from a computer to a printer of an image printing system according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing an image printing system to which an image data transmission method according to the present invention is applied.

Referring to the drawings, an image printing system has a computer 10 and a printer 20 interconnected by a communication interface 30, such as a cable or a network.

The user computer 10 has a central processing unit (CPU) 11, a memory device 12, an input device 13, and a display device 14 interconnected by a bus 17. The input device 13 includes a keyboard and a mouse.

The storage device 12 is provided with a JPEG 12a compression program and a printer driver 12b. As the compression program, SPIHT (Set Partitioning in Hierarchical Trees) and the like may be applied to the user's request in addition to JPEG 12a. The printer driver 12b is responsible for determining the compression rate and transmitting the compressed image data to the printer 20.

On the other hand, the printer 20 connected to the computer 10 by the communication interface 30 includes a main controller 21, a memory device 22, an input device 23, a display device 24, and an engine controller. 25 and a printer engine 26 are provided.

The main controller 21 converts the translation of the data received from the computer 10 through the communication interface 30 and the translated data into driving data suitable for engine driving, and outputs it to the engine controller 25.

The engine controller 25 controls the print job of the printer engine 26 in accordance with the drive data.

In the wet electrophotographic method using ink as a developer, the printer engine 26 feeds an optical scanning device for forming an electrostatic latent image on a photosensitive medium, a developer for developing an electrostatic latent image formed on the photosensitive medium, and an image formed on the photosensitive medium. It has a transfer device for transferring to a sheet of paper.

The input device 23 is provided outside the main body so that a plurality of input keys are provided to select various printing functions provided by the printer 20, and a key input signal is output to the main controller 21.

The image printing system will be described with reference to FIG. 2, which shows a flow chart of the image data transmission method according to the present invention.

When the user specifies the print target image source file using the input device 13 and issues a print instruction command requesting that the designated image source file be printed by the printer 20 (step 110), the computer 10 (B) obtains job waiting time information corresponding to the start of the print job for the image data to which the print job is newly given from the printer 20 (step 120). At this time, the printer 20 generates the waiting time information as part of the status information periodically or upon request from the computer 10. Here, the job waiting time information refers to the job waiting time of the job data corresponding to the start of the print job for the job data transmitted by the printer 20 when the data is transmitted to the printer to request the current print job. For example, if the printer 20 is in the current power saving mode and cannot immediately start a print job, or if there are jobs waiting to be turned on, the printer 20 determines whether the printer 20 is in the waiting amount of work or the current power saving mode. Determine the waiting time information.

In step 130, when the job waiting time information is obtained from the printer 20, the computer 10 transmits the data to be applied when transferring the image source file to the printer 20 from the job waiting time and the data capacity of the image source file to be printed. Determine the compression rate. Typically, the data compression ratio is expressed by dividing the data amount of the original file by the amount of data generated by compression. For example, in the case of JPEG, as the compression rate is increased, the quality of the compressed image is lower than that of the original image. That is, as the compression ratio is increased, the amount of information loss of the image original image obtained by the final compression increases, and as a result, the image quality obtained by decoding the compressed data is deteriorated.

In view of this, it is desirable to determine the maximum compression rate at a level where it is difficult to find a large difference from the original image when visually identifying the reproduced image of the compressed information, and to determine the compression rate below the maximum compression rate. Then, when the waiting time obtained is longer than the time required for transmitting the data capacity of the image compressed file to be generated and compressed with respect to the image source file at the set maximum compression rate, the printer 20 during the waiting time. It is desirable that the compression ratio be determined in such a way that the amount of data transmission capable of sending data to the same size and the capacity of the image compressed file generated by compressing the original image file are equal.

If the compression rate is determined by this method, an image compression file is generated by the data compression program according to the compression rate determined from the data of the image source file (step 140).

Thereafter, the generated image compressed file is transmitted to the printer (step 150).

The printer decodes the transmitted image compressed file, and performs a printing operation so that the decoded image information is printed on paper (step 160).

As described so far, according to the image data transmission method from the computer to the printer of the image printing system according to the present invention, the transmission capacity of the image compressed file generated by the data compression is about the working waiting time that the printer informs. By adjusting the compression rate to minimize the amount of data lost during compression, it is possible to improve the print quality.

Claims (3)

A method of transferring image data from a computer to a printer of an image printing system comprising a computer and a printer connected to the computer by a communication interface, If there is a print instruction for a predetermined image source file, the computer obtaining, from the printer, job waiting time information corresponding to the start of the print job for the image data to which a new print job is to be given; Determining a data compression ratio to be applied when the image source file is transmitted to the printer from the waiting time and the data capacity of the image source file; Generating an image compressed file corresponding to a compression ratio determined from data of the image source file by a predetermined data compression program; And transmitting the compressed image file to a printer. The method of claim 1, further comprising: transmitting the compressed image file to a printer. A method according to claim 1, wherein the compression program is JPEG. The work waiting time according to claim 1, wherein when the work waiting time is longer than a time required to transmit a data capacity of an image compressed file to be compressed and generated with respect to the image original file at a set maximum compression rate, And the compression ratio is determined so that the data transmission amount capable of sending data to the printer and the capacity of the image compressed file generated by compressing the original image file are the same. The image data from the computer of the image printing system to the printer is determined. Transmission method.