Patent Application
20060158468
This application claims the benefit under 35 U.S.C. ยง 119(a) of Korean Patent Application No. 10-2005-0004440, filed in the Korean Intellectual Property Office on Jan. 18, 2005, and Korean Patent Application No. 10-2005-0025371, filed in the Korean Intellectual Property Office on Mar. 28, 2005, the entire disclosures of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an image input/output module and an image input/output apparatus and method employing the same. More particularly, the present invention relates to an image input/output module using an array inkjet head as an output module, and an image input/output apparatus and method employing the same.
2. Description of the Related Art
The image input/output apparatus is structured in a simple manner, such that the sheet of paper P and the document D are fed along the common feed path by the common feed unit 4. However, the conventional image input/output apparatus has the following drawbacks.
First, since the scan unit 3 and the document D are moved in the main scanning direction M and the sub-scanning direction S, respectively, while the image is read from the document D, high scanning precision is very difficult to maintain.
Second, since the feed unit 4 is generally designed to feed the sheet of paper P, the sheet of paper P and the document D have limitations in allowable thickness to be properly fed. However, in general, documents D have various thickness. If a document D with thickness beyond the allowable thickness or a defective document D is fed, feeding precision is deteriorated.
Third, when a copy function is performed, an image should be printed on the sheet of paper P after image information corresponding to at least one page is completely read from the document D. Accordingly, copy speed is very slow and a memory is required that is capable of storing image information corresponding to at least one page. In particular, since a process of copying a color image requires a greater amount of image information, a huge memory is often required, thereby increasing the cost of the image input/output apparatus.
Accordingly, a need exists for a system and method for an image input/output apparatus that maintains high scanning precision regardless of document thickness and requiring minimal memory.
Embodiments of the present invention substantially solve the above and other problems, and provide an image input/output module employing an array inkjet head as a print module. Embodiments of the present invention ensure high speed printing by employing an array inkjet head with a length corresponding to a width of a sheet of paper.
Embodiments of the present invention also provide an inexpensive, compact image input/output apparatus and method.
Embodiments of the present invention also provide an image input/output apparatus and method which can ensure high quality printing and scanning.
According to an aspect of the present invention, an image input/output apparatus is provided comprising a document support on which a document can be loaded, a platen disposed in parallel to the document support for allowing a sheet of paper to be loaded thereon, and an image input/output module disposed between the document support and the platen and configured to be moved in a sub-scanning direction, wherein the image input/output module comprises an array inkjet head including a nozzle unit with a length corresponding to a width of the sheet of paper for printing an image on the sheet of paper and a scan unit for reading image information from the document.
The image input/output apparatus may further comprise a feed unit for drawing up and loading the sheet of paper on the platen, and a discharge unit for discharging the sheet of paper on which printing is completed. While printing is performed by the array inkjet head, the sheet of paper may be in a position selected from the group consisting of a position wherein a front end of the sheet of paper is inserted into the discharge unit, a position wherein a rear end of the sheet of paper is inserted into the feed unit, and a position wherein the front end and the rear end of the sheet of paper are inserted into the discharge unit and the feed unit, respectively.
The platen may be comprised of a belt that is circulated in the sub-scanning direction.
The image input/output apparatus may further comprise a negative pressure providing unit disposed under the platen for providing a negative pressure to prevent the sheet of paper from coming off the platen.
The image input/output apparatus may further comprise guide members installed in the sub-scanning direction for guiding the image input/output module in the sub-scanning direction, and a motor for moving the image input/output module in the sub-scanning direction.
The image input/output apparatus may further comprise a paper supply cassette on which the sheet of paper is loaded, wherein the paper supply cassette is disposed under the platen and forms a C-shaped paper feed path.
The image input/output apparatus may further comprise a paper supply cassette on which the sheet of paper is loaded, wherein the paper supply cassette is installed in the form of a bin and forms an L-shaped paper feed path.
According to another aspect of the present invention, an image input/output module is provided comprising an array inkjet head including a nozzle unit with a length corresponding to a width of a sheet of paper for printing an image on the sheet of paper, and a scan unit directed in a direction opposite to that of the inkjet head for reading image information from a document.
According to still another aspect of the present invention, a method is provided of inputting and outputting an image using an image input/output apparatus that includes a document support, a platen, and an image input/output module having an array inkjet head and a scan unit disposed between the document support and the platen, the method comprising the steps of reading image information on at least one line from the document loaded on the document support using the scan unit while moving the image input/output module in a sub-scanning direction, converting the read image information into print information, and printing an image on a sheet of paper loaded on a platen according to the print information using the inkjet head.
According to yet another aspect of the present invention, a method is provided of inputting and outputting an image using an image input/output apparatus that includes a document support, a platen, and an image input/output module having an array inkjet head and a scan unit disposed between the document support and the platen, the method comprising the steps of reading image information corresponding to one page from the document loaded on the document support using the scan unit while moving the image input/output module in a sub-scanning direction, converting the read image information into print information, and printing an image on a sheet of paper loaded on the platen according to the print information using the image input/output module.
After the scanning is completed, the printing of the image on the sheet of paper may comprise the step of printing an image on a sheet of paper while moving the image input/output module in a direction opposite to the direction during the scanning.
After the scanning is completed, the printing of the image on the sheet of paper may further comprise the step of returning the image input/output module to its original position and printing an image on a sheet of paper while moving the same in the sub-scanning direction again.
After the scanning is completed, the printing of the image on the sheet of paper may still further comprise the step of placing the image input/output module at a predetermined position and printing an image on a sheet of paper while moving the sheet of paper in the sub-scanning direction.
The method may further comprise the step of supplying the sheet of paper into position on the platen before the reading of the image information from the document.
The sheet of paper may be placed in a position selected from the group consisting of a position wherein a front end of the sheet of paper is inserted into a discharge unit, a position wherein a rear end of the sheet of paper is inserted into a feed unit, and a position wherein the front end and the rear end of the sheet of paper are respectively inserted into the discharge unit and the feed unit.
The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings, in which:
Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures.
The present invention will now be described more fully with reference to the accompanying drawings, in which a number of exemplary embodiments of the present invention are shown.
Unlike a conventional inkjet head 1 shown in
Returning to
The platen 20 supports a rear surface of the sheet of paper P and maintains a distance between a top surface of the sheet of paper P and the nozzle unit 31. In an exemplary embodiment of the present invention, the distance may range from about 0.5 mm to about 2.5 mm. To maintain the distance during printing, the image input/output apparatus may further comprise a negative pressure providing unit that provides a negative pressure to the rear surface of the sheet of paper P. For example, the negative pressure providing unit can comprise air vents 21 formed in the platen 20, and a fan 22 disposed under the platen 20. The fan 22 sucks air in through the air vents 21 as shown in
A feed unit 60 is provided for drawing up and loading the sheet of paper P on the platen 20 and is installed at an inlet side of the inkjet head 30. The feed unit 60 may comprise a feed roller 61, and an idle roller 62 contacting and driven by the feed roller 61. A discharge unit 70 is provided for discharging the sheet of paper P on which printing is completed from the platen 20 and is installed at an outlet side of the platen 20. The discharge unit 70 may comprise a discharge roller 71, and a star wheel 72 contacting and rotated by the discharge roller 71 and point-contacting the top surface of the sheet of paper P.
A paper supply cassette 80 on which sheets of paper P are loaded is disposed under the platen 20 as shown in
As shown in
The scan unit 40 and the inkjet head 30 may also be mounted on the carriage 90. Alternatively, in another embodiment of the present invention, the inkjet head 30 may be mounted on the carriage 90 and the scan unit 40 may be coupled to the inkjet head 30. In still another embodiment of the present invention, the inkjet head 30 and the scan unit 40 may be integrally formed with each other. If the inkjet head 30 and the scan unit 40 are integrally formed with each other, they can share parts, such as a cable (not shown) which is used for providing electrical connections to a control unit (not shown), and a frame (not shown) which defines an outer appearance of the image input/output module 50. Further, in yet another embodiment of the present invention, the scan unit 40 and the inkjet head 30 may be directly supported by the shafts 91 without the carriage 90.
A method of inputting and outputting an image using an exemplary image input/output apparatus constructed as above will now be described in greater detail.
Returning to
To read image information from the document D, the document D is loaded on the document support 10 and a document cover 11 is closed. If a user presses an image input button 84 on an operation panel 83, or sends an image input command through the host computer (not shown), the motor 92 is normally rotated and thus, the image input/output module 50 is moved in the sub-scanning direction S. The scan unit 40 may emit light to the document D, detect a reflected light signal, and read image information recorded on the document D. The image information may be transferred to a storage device (not shown) of the host computer. After the scanning is completed, if the motor 92 is reversely rotated, the image input/output module 50 returns to its original position.
To copy the document D, the document D is loaded on the document support 10 and the document cover 11 is closed. If the user presses a copy button 85 on the operation panel 83, or sends a copy command through the host computer, the sheet of paper P is picked up by the pickup roller 81 from the paper supply cassette 80 and is drawn up and loaded on the platen 20 by the feed unit 60. When the front end and the rear end of the sheet of paper P are respectively inserted into the discharge unit 70 and the feed unit 60 to a degree, or when the rear end of the sheet of paper P is inserted into the feed unit 60 to a degree before the front end of the sheet of paper P reaches the discharge unit 70, or even when the front end of the sheet of paper P is inserted into the discharge unit 70 to a degree and the rear end of the sheet of paper P is separated from the feed unit 60, the start of printing is awaited and can be performed. If the motor 92 is normally rotated, the image input/output module 50 is moved in the sub-scanning direction S. The scan unit 40 may emit light to the document D, detect a reflected light signal, and read a line of image information or a band of image information containing a plurality of lines recorded on the document D. The image information is converted into print information using an image processor (not shown) and then input to the inkjet head 30. The inkjet head 30 ejects ink according to the print information to print an image on the sheet of paper P.
Since the image processor converts the image information into the print information in almost real time, scanning and printing operations are simultaneously performed with a gap of one line or one band therebetween. Accordingly, almost real time copying is possible. The exemplary embodiment of the image input/output apparatus therefore needs only a buffer memory that is capable of storing image information of at least one line or one band. Accordingly, a more inexpensive image input/output apparatus can be realized than with a conventional image input/output apparatus, in which the document and the sheet of paper have the same path.
While the scanning and/or copying operation is performed, only the scan unit 40 is moved in the sub-scanning direction S and the document D is stopped. Accordingly, more precise scanning can be done than in the conventional image input/output apparatus in which the document D and the scan unit 40 are moved simultaneously.
In general, an image forming apparatus employing the array inkjet head 30 is structured such that the inkjet head 30 is fixed and the sheet of paper P is moved in the sub-scanning direction S. To perform flatbed scanning using the image forming apparatus, the scan unit 40 should preferably be moved in the sub-scanning direction S. Also, since the motor 92 for moving the scan unit 40 and a motor (not shown) for feeding the sheet of paper P should be simultaneously driven to perform copying, the image forming apparatus should preferably precisely control both motors, thereby increasing a control burden of a control unit (not shown). Also, the vibration of the motor generated during the feeding of the sheet of paper P may affect the scanning, thereby deteriorating scanning precision.
The image input/output apparatus of the exemplary embodiments of the present invention moves the inkjet head 30 and the scan unit 40 alike in the sub-scanning direction S, and does not feed the sheet of paper P during a copying process. Accordingly, only the motor 92 for moving the inkjet head 30 and the scan unit 40 needs to be controlled, thereby reducing a control burden of the control unit. Also, vibration is low and thus, precise scanning can be achieved.
In general, the feeding precision of the sheet of paper P is lower than the feeding precision of the inkjet head 30. Since the sheet of paper P is fed due to friction among the feed roller 61, the idle roller 62, and the sheet of paper P, a slip may occur. Since the inkjet head 30 is moved by the very precise timing belt (or wire) 93 and guided by the shafts 91, the inkjet head 30 can be moved in a very precise manner. Since the inkjet head 30 prints an image on the sheet of paper P while being moved in the sub-scanning direction S, the exemplary image input/output apparatus of the present embodiment can ensure higher print quality than the conventional apparatus in which the inkjet head 30 is fixed and the sheet of paper P is fed in the sub-scanning direction S. Also, since the inkjet head 30 is moved together with the scan unit 40, a separate unit for moving the inkjet head 30 in the sub-scanning direction S is not required.
If a buffer memory that is capable of storing image information corresponding to one page is employed, a scanning process and a printing process may be separated to further improve scan and print quality. In detail, image information is read from a front end of the document D while the image input/output module 50 is moved in the sub-scanning direction S, and is then stored in the buffer memory. When scanning to a rear end of the document D is completed, the input image information is converted into print information using the image processor. The image input/output module 50 then prints an image on the sheet of paper P according to the print information while being moved in a direction opposite to the direction during the scanning. However, at the same time that the image information is read from the front end to the rear end of the document D, the input image information may be converted into print image for printing using the image processor. In this way, although the scanning process and the printing process are separated, the copying process can be performed through one-time reciprocation of the image input/output module 50, thereby preventing a low copy speed.
The image input/output module 50 may return to its original position after the scanning is completed and then move again in the sub-scanning direction S to print an image on the sheet of paper P. Also, the image input/output module 50 may be placed in a position, such as a position after the scanning, its original position, or an arbitrary position between the two positions, after the scanning is completed and then the sheet of paper P may be moved in the sub-scanning direction S to print an image thereon.
A display unit (not shown) such as a liquid crystal display unit may be further provided on the operation panel 83 to display an operating state of the image input/output apparatus. The user can recognize the operating state of the image input/output apparatus, for example, which operation including printing, scanning, and copying operations is being performed or whether the operation is completed, from information displayed on the display unit.
The platen 20 may be comprised of a belt 25, which is circulated in the sub-scanning direction S as shown in
As described above, the image input/output module, image input/output apparatus, and method for inputting and outputting an image according to an embodiment of the present invention has at least the following advantages.
First, an image input/output apparatus that is capable of copying information in almost real time can be realized. An inexpensive image input/output apparatus can be realized since copying can be performed with a small buffer memory that only needs to be capable of storing one line or one band of image information.
Second, since the inkjet head and the scan unit are moved in the sub-scanning direction and the sheet of paper is not moved while copying is performed, the control burden of the control unit is lowered. Also, since low vibration occurs, precise scanning can be performed.
Third, since an image can be printed on the sheet of paper while the inkjet head is precisely moved in the sub-scanning direction, higher print quality can be ensured than in the conventional methods in which the sheet of paper is fed in the sub-scanning direction.
Fourth, if a buffer memory that is capable of storing image information corresponding to one page is employed, scan and print quality can be further improved by separating scanning and printing processes.
Fifth, a slim flatbed image input/output apparatus with a minimum foot-print design can be realized according to a position of the paper supply cassette.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2005-0004440 | Jan 2005 | KR | national |
| 10-2005-0025371 | Mar 2005 | KR | national |
