Patent Application
20100080574
1. Field of the Invention
This invention relates to a printing device, and in particular, it relates to a printing device with a sensor for the output tray.
2. Description of Related Art
In conventional printers, when a paper jam or other printing error occurs, the printer notifies the user of the error, and resumes printing after the user clears the jam or other error. The printer typically re-prints the page or pages that were not properly printed due to the error. However, sometimes the printer may not correctly re-print the pages, and as a result, some pages may not be printed, or extra pages may be printed.
Accordingly, the present invention is directed to a printing device and related method that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a convenient way to warn a user when incorrect jam recovery occures.
Additional features and advantages of the invention will be set forth in the descriptions that follow and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
To achieve these and/or other objects, as embodied and broadly described, the present invention provides a printing device which includes: a print engine for forming images on sheets of recording media; an output device for receiving sheets outputted from the print engine; an I/O section for receiving a print job; a control section; and a sensor device associated with the output device and connected to the control section, the sensor device detecting sheets outputted from the print engine to the output device, wherein the control section obtains a number of sheets to be printed for a print job, obtains from the sensor device a number of sheets actually outputted to the output device for the print job, and compares the number of sheets to be printed and the number of sheets actually outputted.
In another aspect, the present invention provides a printing method implemented in a printer, which includes: (a) receiving a print job; (b) obtaining a number of sheets to be printed for the print job; (c) generating a plurality of printed sheets based on the print job and outputting them to an output device of the printer; (d) detecting a number of sheets actually outputted to the output device for the print job; and (e) comparing the number of sheets to be printed and the number of sheets actually outputted to the output device.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
To solve the problem of incorrect jam recovery, a printer is equipped with one or more sensors to detect the number of sheets (recording media) outputted to the output tray of the printer. The number of sheets outputted to the tray for a print job is counted, and compared to the number of pages to be printed in the print job. The number of pages for a print job is obtained from the device (e.g. a computer) that submitted the print job, or from the print data itself. If the number of sheets detected by the sensor does not agree with the number of pages in the print job, the printer notifies the user of the mismatch. The user may then inspect the printed sheets to determine whether some pages are missing or extra pages have been printed, and take appropriate corrective actions such as re-printing the missing pages or discarding the extra pages.
The printer 200 includes a control section 201, an image processing section 202, a print engine 203, an input/output (I/O) section 204, a user interface section 205, and one or more sensors 206. The control section 201 includes a central processing unit (CPU), a random access memory (RAM), and a read only memory (ROM). The CPU reads out various software programs stored in the ROM into the RAM to control the internal sections 202 through 206 of the printer 200. The image processing section 202 carries out various image processing under the control of the CPU 201, and sends the processed image data to the print engine 203. The print engine 203, which for instance employs the electrophotographic process, forms an image on a recording sheet based on the image data sent from the image processing section 202. The I/O section accepts print data from PC 100. The user interface section 205 includes various input keys and/or display devices such as indicator lights or a display panel.
According to embodiments of the present invention, one or more sensors 206 are provided in the printer 200 to detect the number of sheets outputted to the output tray. The sensor may be physically located near where printed sheets exit the sheet transport mechanism of the print engine, or at other locations of the output tray. The sensor may be an optical sensor, an electrical sensor, a mechanical sensor, or any other suitable types of sensors, or a combination thereof. Preferably, the sensor 206 detects completely outputted sheets; sheets that are partially outputted to the tray due to an error are not counted. In one example, the sensor is located at the exit of the sheet transport mechanism and checks whether each sheet passed through completely or not. In another example, the sensor has the ability to measure the paper length which passes through the sensor, and compare it to the paper length of the print job. For example, the paper length should be 8.5 inches if the print job specifies letter sized paper in portrait orientation, or 11 inches if the print job specifies letter sized paper in landscape orientation. The sensor receives signals from the control section 201 indicating the start and end of a print job, detects and counts the number of outputted sheets for the print job, and sends the result to the control section 201. The sensor 206 includes appropriate circuitry to perform the counting functions.
The total number of pages to be printed in a print job is obtained from the print job itself. In some cases, the print job received from the computer includes commands or a job ticket that accompanies the file to be printed. The commands or job ticket specifies various printing requirements including the number of copies to be printed and (if appropriate) the page range of the file to be printed. In such a case, the printer 200 obtains the total number of pages using the information contained in the command or the job ticket. In some other cases, the printer 200 receives from the computer 100 print data (e.g. PDL data) for the print job without a command or job ticket containing the requisite information. In such a case, the printer 100 obtains the total number of pages by examining the print data. Further, a print job may request printing multiple copies of the document, or printing selected pages of the document. In such instances, the total number of pages of the print job is calculated from the number of copies and/or the page range.
After printing is finished, the control section 201 compares the total number of pages to be printed (obtained from the job ticket or the print data) with the total number of pages actually printed (detected by the sensor). If the numbers do not match, the printer generates a warning signal indicating such a mismatch. The warning signal may take a variety of forms. For example, it may be a simple warning light, located on the printer's control panel or near the sensor or at other suitable locations on the printer, that will be lit when a mismatch occurs. Another example is an audible signal such as a beep. Another example is a message displayed on a display (e.g. an LCD screen) on the control panel of the printer. Another example is a message displayed on the monitor of the computer 100 that submitted the print job (i.e. the printer sends a message to the computer). The warning signal may also be a combination of the above or any other suitable form of signals.
The printer 200 may include multiple output trays, collectively referred to as the output device. Each tray may be equipped with one or more sensors, collectively referred to as the sensor device. A print job may output to more than one tray, in which case the total number of outputted sheets for the print job is the sum of detected output sheets in all trays. Further, the print command or job ticket may specify which output trays are to be used for the print job and how many pages are to be outputted to each tray. For example, the job ticket may specify that the document contains twenty pages, and that three copies of the document are to be printed and each copy is to be outputted to a separate output tray. If each output tray is equipped with a sensor, the sensor device detects and counts the number of sheets outputted to each tray. The control section 201 may compare the actual number of sheets outputted to each tray with the number of sheets to be outputted to each tray as specified in the jot ticket, and generate a warning signal if one or more mismatches in the numbers are found. For example, a warning light associated with the output tray that has a mismatch may be lit.
Although the descriptions above use a printer as an example, the invention may also be applicable in a so-called all-in-one or multi-function device, which is a device that combines printing, scanning, and copying functions. More generally, the invention is applicable in any device that includes a printing function. The terms “printer” or “printing device” as used in this disclosure and the appended claims should be understood to broadly refer to all such devices.
Further, although
It will be apparent to those skilled in the art that various modification and variations can be made in the printing device and related method of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover modifications and variations that come within the scope of the appended claims and their equivalents.
