KR20010009062A - Apparatus for detecting of paper size - Google Patents

Abstract

PURPOSE: A device for sensing size of paper is provided to check the size of various print papers and to prevent the unnecessary print work due to an error of selecting the size of the print paper. CONSTITUTION: A device for sensing size of paper connected with a host computer(200) to be capable of interfacing and printing print data received from the host computer, includes a paper size sensing part(160) sensing the size of the printing paper for recording the print data by using an image sensor(163), a paper size detecting part(170) detecting the size of the printing paper by counting the number of the pixels matching with brightness data of the printing paper in brightness data input from the paper size sensing part, a comparing part(180) comparing the size of the printing paper detected in the detecting part with the paper size of the print data, and a control part(110) performing printing work of the print data if the sizes are equal and displaying the error if the sizes are not equal.

Description

Apparatus for detecting of paper size}

The present invention relates to a paper size detecting device, and more particularly, a paper for detecting the size of various types of printing paper by using an image sensor when detecting the size of the printing paper loaded in order to perform a print job in the printer. It relates to a size sensing device.

In general, a printing apparatus such as a printer or a copying machine includes a paper cassette as a paper loading means for loading paper for use in printing, as shown in FIG.

1 is a plan view schematically showing a paper cassette structure for detecting a general paper size.

The paper cassette 10 is capable of loading paper of various sizes that can be used for printing, and in the accompanying drawings, a paper cassette capable of loading paper of B5, A4, B4, and A3 sizes is shown. In addition, the paper cassette 10 has a structure in which B5 and A4 size paper can be loaded in a wide (W) direction or a narrow (Narrow) N direction.

In the case of a printing apparatus using a paper cassette in which different sizes of paper are loaded in various directions, the size and direction of the paper loaded in the paper cassette must match the size and orientation of the paper set by the user when printing. In order to transfer the information to the printing apparatus, conventionally, as shown in FIG. 1, when the indicator 11 mounted at one end of the paper cassette is switched to indicate the size of the loaded paper. The central processing unit (not shown) of the printing apparatus recognizes the size (and stacking direction) of the loaded paper through the detection signal generated by the switch 12 (or optical sensor) according to the position of the indicator 11. This is used.

Alternatively, depending on the product, a method in which a user determines the size and orientation of the paper used for printing on an operation panel of a printing apparatus or a driver of a computer is used.

The above-described method is inconvenient because the user arbitrarily switches the indicators installed in the paper cassette so that the printing apparatus must recognize the loaded paper size and direction, and the user switches the indicators according to the size or direction of the loaded paper. If not, the printing apparatus had a problem that the printed matter was not output correctly because the size or orientation of the loaded paper was incorrectly recognized.

In addition, the method of determining the size and orientation of the paper to be used for printing on the operation panel or the driver of the computer is performed by the user operating the key on the operation panel before printing the image data provided by the computer. By printing after setting, the size of the paper printed by the actual engine device and the size of the printing paper set by the user may not match each other, and thus the desired image data may not be printed properly on the paper. When the size of the printing paper is changed, the user has an inconvenience of having to reset the size of the printing paper through the operation panel.

In order to solve this problem, a photo sensor or a push switch may be configured inside the paper cassette 10 or on a paper conveying path to automatically identify the size of the paper loaded in the paper cassette 10. A method has also been proposed.

However, when a photo sensor or a push switch is used, a problem arises in that a photo sensor or a push switch must be provided so as to correspond to paper of various sizes loaded in a paper cassette. That is, when a limited photo sensor or a push switch is used, the size of the paper that can be detected is limited, and thus, paper of various sizes cannot be detected, and a plurality of photo sensors or push switches are used to correspond to various sizes of paper. In that case, the cost rises.

Accordingly, the present invention has been made to solve such problems, and an object of the present invention is to mount one image sensor without using a plurality of photo sensors or a push switch on a paper conveyance path to automatically mount various types of paper sizes. It is to provide a paper size detection device to identify with.

1 is a plan view schematically showing a paper cassette structure for detecting a general paper size;

2 is a schematic block diagram of a printer for detecting a paper size according to the present invention;

3A to 3B are schematic configuration diagrams of the paper size detecting unit shown in FIG.

Figure 4 is a flow chart for detecting the paper size in accordance with the present invention.

<Description of the code | symbol about the principal part of drawing>

110: controller 120: memory

130: operation panel 140: engine controller

150: printer engine 160: paper size detection unit

170: paper size detection unit 180: comparison unit

A feature of the present invention for achieving the above object is a paper size sensing apparatus of a printer that is interfaced with a host computer so as to be able to interface therewith and prints print data received from the host computer: A paper size detection unit for detecting the size using an image sensor, a paper size detection unit for detecting the size of the printing paper by counting the number of pixels matching the brightness data of the printing paper among the brightness data input from the paper size detection unit; A comparison unit for comparing the size of the print paper detected by the paper size detection unit with the paper size of the print data, and if the comparison result is the same, perform printing of the print data. It includes a control unit that represents.

Here, the image sensor is preferably installed at the lower end of the paper cassette on which printing paper is loaded.

Here, the image sensor is preferably installed on the upper end of the cassette case into which the paper cassette on which printing paper is loaded is inserted.

Here, the image sensor is preferably installed before the printing paper is fed from the transfer path of the printing paper and fed to the image forming unit for recording the printing data on the printing paper.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the elements of each drawing, it should be noted that the same elements are denoted by the same reference numerals as much as possible even if they are displayed on different drawings. In addition, in the following description there are shown a number of specific details, such as components of the specific circuit, which are provided only to help a more general understanding of the present invention that the present invention may be practiced without these specific details. It is self-evident to those of ordinary knowledge in Esau. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

2 is a schematic block diagram of a printer for detecting a paper size according to the present invention, FIG. 3 is a schematic configuration diagram of the paper size sensing unit shown in FIG. 2, and FIG. The operation flow chart for detecting the paper size is shown.

As shown in FIG. 2, the control unit 110 receives the print data transmitted from the host computer 200 according to a predetermined program to control printing, and in particular, to perform a print job according to a preferred embodiment of the present invention. The size of the print paper is detected before, and the print data is controlled.

The memory 120 accesses or stores the received image data according to the operation program of the controller 110, the general control program, and the control of the controller 110, and in particular, the number of pixels of brightness data corresponding to printing paper of various sizes. Is stored.

The operation panel 130 has a plurality of keys capable of generating function key data of the system, and when the key data is generated, the control panel 130 may input the same to the controller 110 and display the display data of the controller 110. It includes.

The engine controller 140 drives the printer engine 150 under the control of the controller 110, and the printer engine 150 controls the image on the printing paper fed and fed from the paper cassette under the control of the engine controller 140. Form.

The paper size detecting unit 160 detects the size of the printing paper loaded in the paper cassette and inputs it to the control unit 110.

The paper size detection unit 170 counts the number of pixels of the brightness data corresponding to the printing paper among the brightness data input from the paper size detection unit 160 and inputs it to the controller 110.

The comparison unit 180 compares the number of pixels counted by the paper size detection unit 170 with the number of pixels pre-stored in the memory 120 to detect a paper having the same size.

Here, the paper size detection unit 160 is a lamp driver 161 for controlling the light emitting state of the lamp 162 under the control of the control unit 110, and the lamp (ON / ON under the control of the lamp driver 161 ( 162 and an image sensor such as a CCD (Charge Coupled Device) or a CIS (Contact Image Sensor) for photoelectric conversion of the reflected light reflected from the printing paper and incident upon the lamp 162 is turned on. 163 and an analog / digital converter 164 converting the analog image information photoelectrically converted by the image sensor 163 into digital image data having a predetermined number of bits (m) and inputting it to the controller 110. do.

The lamp 162 and the image sensor 163 of the paper size detecting unit 160 are mounted on a paper cassette or mounted on a conveyance path of printing paper to detect various kinds of paper sizes loaded on the paper cassette.

3A illustrates a paper size detecting unit 160 installed at the bottom 310 of the paper cassette 300, and FIG. 3B illustrates a paper size sensing at the top 330 of the cassette case 320 into which the paper cassette 300 is inserted. The unit 160 is installed.

An operation of the present invention having such a configuration will be described in detail with reference to FIG. 4.

First, when a print command is received from the host computer 200 (S401), the controller 110 checks whether paper is loaded in the paper cassette (S402), and if the print paper is loaded, controls the engine controller 140 to control the printer. A predetermined voltage is applied to each roller (not shown) of the engine 150 to drive it (S403), and the print data received from the host computer 200 is stored in the memory 120 (S404).

Thereafter, the controller 110 detects the size of the print paper loaded in the paper cassette 300 through the paper size detector 160 before printing the print data stored in the memory 120 through the printer engine 150. (S405).

Here, a method of detecting the size of the printing paper loaded in the paper cassette 300 will be described in more detail.

When the print command is received from the host computer 200, the controller 110 controls the lamp driver 161 to turn on the lamp 162. Light emitted from the lamp 162 is reflected by the printing paper loaded on the paper cassette 300 and received by the image sensor 163. The image sensor 163 converts the light reflected from the printing paper into an electrical signal and provides the analog / digital converter 164. The analog / digital converter 164 converts an analog signal provided by the image sensor 163 into a digital form. In this case, the digitized data is divided into various levels of brightness data according to a predetermined number of bits and output. For example, assuming that the analog / digital conversion unit 164 converts analog image information into 8-bit digital image data, the maximum brightness value M of the converted digital image data is 255 by 2 ^m −1. (Ie, 2 ⁸ -1 = 255). Here, although the gray level of the binarization target image used in the present invention is preferably used, 256 gray scales representing a single pixel as 8 bits can be added or subtracted according to each application field.

The analog / digital converter 164 inputs brightness data of a predetermined grade detected at each pixel position to the controller 110, and the controller 110 records the brightness data input from the analog / digital converter 164. Input to the size detection unit 170.

The paper size detector 170 counts brightness data corresponding to the printing paper among the brightness data at each pixel position input from the analog / digital converter 164. That is, since the print paper is a white pattern, the brightness data detected by the analog-digital converter 164 is 255 levels. Therefore, the paper size detector 170 checks the brightness data input from the analog / digital converter 164 and checks the number of pixels for which the brightness data is continuously input at 255 levels. Here, although the printing paper is a white pattern, the brightness data cannot always be 255 levels according to various contaminants or types of printing paper. It is preferable to set it to the range which has.

If the size of the print paper loaded in the paper cassette 300 is detected in step 405 (S405), the controller 110 detects the paper size of the print data stored in the memory 120 and the paper size detected from the paper size detector 160. Is compared (S406).

That is, the number of pixels counted by the paper size detector 170 is input to the comparator 180 under the control of the controller 110, and the comparator 180 counts the number of pixels and the memory counted by the paper size detector 170. The number of pixels corresponding to printing paper of various sizes previously stored in 120 is compared. In this case, the number of pixels to which the 255 level is input in correspondence with the printing paper of various sizes is pre-stored in the memory 120. The number of pixels stored corresponding to the paper size is preferably input within a range having a margin.

The control unit 110 checks whether the two paper sizes match (S407), and if the two paper sizes do not match, the control unit 110 indicates the occurrence of an error and does not perform a print job (S409), and the two paper sizes match. The controller 110 controls the engine controller 140 to perform a print job of recording the print data stored in the memory 120 through the printer engine 150 on the print paper loaded in the paper cassette 300 (S408). ).

Here, at least one paper cassette may exist. If at least one paper cassette exists, the paper size of the print data stored in the memory 120 among the paper sizes detected by the paper size detector 160 in the same manner as described above. Of course, it detects the paper cassette matching the.

On the other hand, when paper is supplied from a separate paper feeder, that is, a manual cassette, instead of printing paper loaded in a paper cassette in the printer, the paper is loaded in the paper cassette 300 as shown in FIG. 3A or 3B. When the size detecting unit 160 is mounted, it is impossible to detect the size of the paper supplied from the manual cassette. In this case, it is preferable to mount on the conveyance path of the printing paper in order to detect the size of the printing paper fed from the paper cassette 300 or the manual cassette before being supplied to the image forming unit (not shown). When the paper size detection unit 160 is installed on the transport path of the printing paper, the printing paper loaded in the paper cassette 300 or the manual cassette is picked up, and then the size of the printing paper to be fed is determined as described above. Is detected and compared with the paper size of the print data stored in the memory 120.

In addition, in the multifunction apparatus including not only the function of the printer but also the function of the scanner, an optical sensor provided for scanning an original can be used. That is, it is also possible to allow the optical sensor for scanning the original to sense the size of the printed paper loaded in the above manner when performing the printing operation of the print data.

Therefore, good image quality can be obtained because the various types of printing paper size information loaded on the paper cassette are checked and notified before the printing operation is performed.

As described above, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

As described above, according to the paper size detecting apparatus according to the present invention, since the size of the printing paper is sensed using the image sensor, it is possible to check all sizes of various types of printing paper, and to set the paper size in the print data. By comparing the size of the paper loaded in the paper cassette and notifying before the printing operation is performed, there is an advantage that can prevent unnecessary printing operation due to the selection error of the printing paper size.

Claims (4)

In the apparatus for detecting the paper size of the printer which is connected to the host computer so that the interface is possible, and prints the print data received from the host computer: A paper size detecting unit for detecting a size of a printing paper on which the print data is recorded by using an image sensor; A paper size detection unit for detecting the size of the printing paper by counting the number of pixels that match the brightness data of the printing paper among the brightness data input from the paper size detecting unit; A comparison unit for comparing whether the size of the print paper detected by the paper size detection unit and the paper size of the print data are the same; And a control unit for performing a print job of the print data if the comparison result is the same, and generating an error if the comparison result is not the same. The apparatus of claim 1, wherein the image sensor is installed at a lower end of a paper cassette on which the printing paper is loaded. The apparatus of claim 1, wherein the image sensor is installed at an upper end of a cassette case into which a paper cassette into which the printing paper is loaded is inserted. The paper size sensing apparatus according to claim 1, wherein the image sensor is installed before the printing paper is fed from the transport path of the printing paper and fed to an image forming unit for recording the printing data on the printing paper. .