JP2021082889A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that can accurately read a bar code displayed on a screen.SOLUTION: An image forming apparatus that can read an image from a document in a platen-set method reads multiple times a bar code displayed on a screen of a smartphone placed on a platen glass in a state where lighting on an object to be read is turned off, and creates a plurality of read images. The image forming apparatus adds up pixel values of pixels corresponding to each other in the plurality of read images to determine a total value. In the individual read images, since a difference in pixel value between a white part and a black part of the bar code is small, it is difficult to accurately distinguish between the white part and the black part under the influence of noise (a), but in an added image, since noise is equalized and the difference in pixel value between the white part and the black part is increased, the distinguishing accuracy is improved (b).SELECTED DRAWING: Figure 7

Description

The present disclosure relates to an image forming apparatus, and more particularly to a technique for improving the reading accuracy of a barcode displayed on a screen.

Bar code payment is one form of electronic payment that has become very popular in recent years. Various products and services are subject to bar code payment, and users can also use bar code payment for the usage charges of multifunction devices (MFPs) installed in stores such as convenience stores. It is possible to improve the convenience of.

There are two types of barcode payment, of which the user scan method payment is also called the store presentation type (MPM: Merchant-Presented Mode), in which the customer holds the smartphone over the barcode presented by the store and reads it. It is for making payments. When the user scan method is applied to the payment of charges for the multifunction device, it is displayed on the operation panel of the multifunction device after the user operates the smartphone to start the application and switches to the screen for reading the barcode. Since the barcode must be read, the user operation is complicated.

If, instead of the user scan method, the store scan method (also called consumer-presented mode (CPM)), in which the store reads the barcode presented by the customer using a barcode reader, is adopted, the payment can be made. Bar code payment can be performed without complicated user operations.

However, the usage fee of the multifunction device installed in the store is often settled at the place where the multifunction device is installed, for example, using a coin-insertion type automatic payment machine instead of the cash register of the store. In line with this, if a barcode reader for performing barcode payment is installed in the multifunction device, the device cost will increase.

For such a problem, if the scanner provided in the multifunction device is made to read the barcode without adding a dedicated barcode reader, it is possible to avoid an increase in the equipment cost.

JP 2015-015664

The scanner provided in the multifunction device irradiates the document with strong illumination light and detects the reflected light in order to read the document clearly. Therefore, in the barcode printed on plain paper, as shown in FIG. 20A, the density difference C2001 between the reading density of the white portion 2001w and the reading density of the black portion 2001b is large, and the contrast characteristic is high. have. Therefore, the white portion and the black portion of the barcode can be accurately discriminated.

On the other hand, since the display screen of the smartphone (hereinafter, abbreviated as "smartphone screen") displays the bar code by emitting light, the reading density of the white portion 2002w cannot be increased even if the smartphone screen is illuminated. The reading density of the white portion 2002w is only the reading density according to the amount of light emitted from the smartphone itself. Since the amount of light emitted from the smartphone is significantly smaller than the amount of illumination light of the scanner, the reading density of the white portion 2002w has to be low, and the density difference C2002 with the reading density of the black portion 2001b is described above. It is smaller than the density difference C2001 when reading a barcode from plain paper.

In the scanned image whose contrast is enhanced by using the strong illumination light as described above, the S / N ratio is high even if noise is superimposed by A / D (Analogue to Digital) conversion in the scanner or data transmission. There are no problems with image quality. On the other hand, the barcode image read from the smartphone screen has low contrast, so that the adverse effect of noise cannot be ignored.

For example, as illustrated in FIG. 20B, even if gain adjustment processing (contrast enhancement processing) is performed to distinguish between a white portion and a black portion, the S / N ratio itself is not improved, so that the influence of noise This causes problems such as cross-linking between white parts and black parts. Therefore, if the width of the white portion or the black portion cannot be detected, the barcode cannot be analyzed accurately.

Such a problem may also occur when reading a barcode from a display screen other than the smartphone screen.

The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide an image forming apparatus capable of accurately reading a barcode displayed on a screen.

In order to achieve the above object, the image forming apparatus according to one embodiment of the present disclosure includes a lighting means for illuminating the reading target and the lighting means along the reading surface of the reading target when reading by the platen set method. An image forming apparatus having a light receiving amount detecting means for detecting a light receiving amount from the reading target and a conversion means for converting the detected light receiving amount into a pixel value while moving together with the reading target. Obtained by the reading target determination means for determining whether or not the bar code is displayed on the display screen of the portable device, the control of the light receiving amount detecting means when the determination is affirmative, and the conversion. By performing at least one of the image processing for changing the pixel value, the difference in the pixel value between the white portion and the black portion of the bar code is increased, and the pixel value is included in the pixel value after the image processing. It is characterized by including a bar code reading control means for averaging noise components among pixels.

In this case, a light-off means for turning off the lighting means may be provided when it is determined that the reading target is a barcode displayed on the display screen.

Further, the reading target determining means includes a receiving means for receiving a designation as to whether or not the reading target is a barcode, and even if the reading target is determined according to the designation received by the receiving means. Alternatively, the read target determining means includes a concentrated area determining means for determining whether or not there is a concentrated area in which pixels whose pixel values obtained by the conversion are equal to or greater than a predetermined threshold are concentrated, and the concentrated area is determined. When it is determined that there is, the reading target may be determined to be a barcode.

Further, in the image processing, the barcode reading control means adds pixel values to pixels estimated to have the same color from positions on the image data, and the obtained pixel values are pixels corresponding to the pixel set. By setting the value, the difference between the pixel values may be increased.

Further, the barcode reading control means was obtained by repeating the work of detecting the light receiving amount a plurality of times while moving the light receiving amount detecting means from the reading start end to the reading end end along the platen glass. Pixels at the same position among a plurality of image data may be estimated as pixels of the same color, and the pixel values may be added.

Further, when the reading target is placed on the platen glass in a state where the bar direction of the bar code coincides with the moving direction of the light receiving amount detecting means, pixels continuous along the bar direction are generated. Pixels of the same color may be estimated, and the pixel values may be added to obtain pixel values of pixels at the same positions as the continuous pixels in a direction orthogonal to the bar direction.

Further, the barcode reading means controls the light receiving amount detecting means to reduce the moving speed thereof so that the same line orthogonal to the bar direction in the barcode is read a plurality of times on the same line. A plurality of pixels corresponding to the same position may be estimated as pixels of the same color, and the pixel values may be added.

Further, the bar code reading means controls the light receiving amount detecting means to set an exposure time for detecting the light receiving amount of one pixel as compared with the case where it is determined that the reading target is not the bar code displayed on the screen. By lengthening the pixel value, the difference between the pixel values may be increased.

Further, when the reading target is placed on the platen glass so that the bar direction of the barcode coincides with the moving direction of the light receiving amount detecting means, the barcode reading means is the reading target. The difference in pixel values may be increased by detecting the amount of light received as one pixel in a wide range in the bar direction, as compared with the case where is determined not to be the bar code displayed on the screen.

Further, the bar code reading means is a ratio of the exposure time when it is determined that the reading target is not the bar code displayed on the screen to the exposure time when it is determined that the reading target is the bar code displayed on the screen. Depending on the situation, the moving speed of the light receiving amount detecting means may be reduced.

Further, when the bar code is displayed so as to move along the moving direction of the received light amount detecting means at the time of reading, the bar code reading control means are located at different positions in the moving direction of the received light amount detecting means. Add the pixel values of the pixels whose light reception amount is detected in the above and the pixels at the corresponding positions on the image data, and use the obtained pixel values as the pixel values of the pixels corresponding to the position. May increase the difference between the pixel values.

Further, when the movement of the barcode along the movement direction intermittently moves at a plurality of positions, the barcode reading means reads the barcodes displayed at the plurality of positions on the scanned image. An image dividing means for dividing at a dividing position and dividing into a plurality of partial images, and an image adding means for adding pixel values of pixels at corresponding positions between the plurality of partial images may be provided. ..

Further, when the bar code continuously moves at a speed slower than the moving speed of the light receiving amount detecting means, among the lines orthogonal to the bar direction on the bar code, the lines adjacent to each other in the bar direction are selected. An image segmentation means for dividing a scanned image into a plurality of partial images at a partitioning position, and a pixel value is added to each of the pixels continuous in the bar direction for each partial image to correspond to a position on the line. An image segmentation means for setting the pixel value of a pixel may be provided.

By doing so, the difference in pixel values between the white portion and the black portion of the barcode is increased, so that the white portion and the black portion can be accurately discriminated, and the barcode analysis can be performed. The accuracy can be improved.

It is an external perspective view of the image forming apparatus 1 which concerns on 1st Embodiment of this disclosure. It is sectional drawing which shows the main structure of the image reading apparatus 100. It is a block diagram explaining the main functional structure of the image forming apparatus 1. FIG. It is a block diagram explaining the main functional structure of the image reading apparatus 100. It is a flowchart explaining the main routine of the reading operation of the image forming apparatus 1. It is a flowchart explaining the bar code reading process which concerns on 1st Embodiment of this disclosure. (A) is a graph explaining the contrast characteristic and the noise component in the barcode image before addition, and (b) is a graph explaining the contrast characteristic and the noise component in the barcode image after addition. It is a flowchart explaining the bar code reading process which concerns on 1st modification of 1st Embodiment of this disclosure. It is a figure which illustrates the bar code image. It is a flowchart explaining the bar code reading process which concerns on the 2nd modification of the 1st Embodiment of this disclosure. It is a flowchart explaining the bar code reading process which concerns on 2nd Embodiment of this disclosure. It is a figure explaining the relationship between the reset period of CMOS sensor 223 and the amount of accumulated electric charge for each pixel. It is a flowchart explaining the bar code reading process which concerns on the modification of the 2nd Embodiment of this disclosure. It is a flowchart explaining the bar code display process of the smartphone 240 which concerns on 3rd Embodiment of this disclosure. (A) exemplifies the barcode displayed at the first position on the smartphone screen, (b) exemplifies the barcode displayed at the second position on the smartphone screen, and (c) exemplifies the barcode displayed at the second position on the smartphone screen, and (c) is read by the image reading device 100. An example of a barcode image is shown. It is a flowchart explaining the bar code reading process which concerns on 3rd Embodiment of this disclosure. It is a flowchart explaining the barcode displayed on the smartphone screen which concerns on the modification of the 3rd Embodiment of this disclosure, the barcode image read by the image reading apparatus 100, and the barcode image after addition. It is a flowchart explaining the execution necessity determination process of the bar code reading process which concerns on the modification of this disclosure. It is a flowchart explaining the execution necessity determination process of another bar code reading process which concerns on the modification of this disclosure. (A) is a figure comparing the contrast characteristic of the barcode image read from plain paper with the contrast characteristic of the barcode image read from the smartphone screen, and (b) is the pixel of the barcode image read from the smartphone screen. An example is an example of a graph before the value gain adjustment and a graph after the gain adjustment.

Hereinafter, embodiments of the image reading device and the image forming device according to the present disclosure will be described with reference to the drawings.
[1] First Embodiment In the present embodiment, a plurality of barcode images are added to equalize the random noise superimposed on the barcode image, and the contrast is emphasized to detect the barcode. Improve accuracy.
(1-1) Configuration of Image Forming Device First, the configuration of the image forming apparatus according to the present embodiment will be described.

As shown in FIG. 1, the image forming apparatus 1 according to the present embodiment is a so-called multi-function peripheral (MFP) having a scanning function, a printing function, a copying function, a facsimile function, a network function, a BOX function, and the like. ), Which includes an image reading device 100, an automatic document feeder (ADF) 110, an image forming device 120, a paper feeding device 130, and an operation panel 140.

The image reading device 100 can read an image by two reading methods, a sheet-through method and a platen set method. As shown in FIG. 2, a slit is opened on the upper surface of the image reading device 100, and the slit is closed by the contact glass 201. The contact glass 201 faces a portion of the document transport path by the automatic document transport device 110 along the bottom surface of the automatic document transport device 110. In the case of the sheet-through method, the document passes over the contact glass 201.

A platen glass 202 is disposed on the upper surface of the image reading device 100, and closes an opening different from the slit in which the contact glass 201 is closed. When the original is read by the platen set method, the original is placed on the platen glass 202. When reading the display screen of the smartphone 240 on which the barcode 241 or the like is displayed (hereinafter, abbreviated as "smartphone screen"), the smartphone 240 is placed on the platen with the smartphone screen facing the platen glass 202 side. Place on glass 202.

The image reading device 100 has a built-in drive motor 231 and pulls the wire 232 by rotating in the direction of arrow A or the direction of arrow B. A slider 233 is fixed to the wire 232. Therefore, when the drive motor 231 pulls the wire 232, the slider 233 reciprocates from directly below the contract glass 201 to the opposite end of the platen glass 202 as viewed from the contact glass 201.

A line light source 210 is built in the slider 233. When the document is read by the platen set method, the slider 233 moves in the arrow C direction (sub-scanning direction) and irradiates the document surface with the illumination light emitted by the line light source 210. The reflected light from the document surface enters the optical element 221 via the folded mirrors 234, 235 and 236. The incident light is focused by the optical elements 221 and 222, and then the amount of light (reflection density) is detected at each position in the main scanning direction by the line sensor 223.

When the line sensor 223 outputs an analog signal according to the amount of detected light, the analog signal is converted into a digital signal and image data is generated. The generated image data is transmitted to the image forming apparatus 120 as described later.

When reading a document by the sheet-through method, image data is generated by illuminating the document surface with a line light source 210 and detecting the amount of reflected light while the slider 233 is stationary directly under the contact glass 201.

When the automatic document conveying device 110 reads the originals by the sheet-through method, the automatic document conveying device 110 feeds out the originals one by one from the highest-ranked originals in the original bundle placed on the platen tray 111 and conveys the originals one by one, and the original surface is contact glass 201. After passing the document through the contact glass 201 while facing the side, the document is ejected onto the output tray 112.

The image forming apparatus 120 forms an image on a recording sheet supplied by the paper feeding apparatus 130 by using the image data generated by the image reading apparatus 100 and the image data received from another apparatus. The image-formed recording sheet is discharged onto the paper ejection tray 121.

The operation panel 140 is arranged on the front side facing the user of the multifunction device 1. The operation panel 140 is provided with a touch panel, hard keys, and a speaker consisting of a flat display and a touch pad, and can display a screen such as a menu screen to the user of the multifunction device 1 or accept touch input or key operation by the user. To do. The operation panel 140 allows the user to freely adjust the angle of the operation surface, and can realize high operability according to the operation posture of the user.
(1-2) Control system of the multifunction device 1 Next, the control system of the multifunction device 1 will be described.

As shown in FIG. 3, the image forming apparatus 120 is equipped with a system controller 300 for controlling the operation of the multifunction device 1. The system controller 300 includes a CPU (Central Processing Unit) 301 and a ROM (Read Only Memory) 302. The CPU 301 starts when it is reset, reads data such as a control program and operating parameters from the ROM 302, and executes the data. As a result, the controller 300 controls the operation of the multifunction device 1 and executes jobs such as a scan job, a print job, a copy job, a facsimile transmission / reception job, and a mail transmission / reception job.

The image forming apparatus 120 further includes an input image processing unit 310, a memory 320, a network interface 330, a printer engine 340, an output image processing unit 350, and a storage device 350, all of which are connected to the system controller 300.

The input image processing unit 310 performs a process of converting the data format of the image data generated by the image reading device 100.

The memory 320 is a RAM (Random Access Memory), which is used as a work storage area when the CPU 301 executes a control program, and data such as image data and temporary data are written and read.

The network interface 330 executes communication processing for sending and receiving job data, e-mail, and the like with other devices via a network to which the multifunction device 1 is connected, such as a LAN (Local Area Network) or the Internet.

The printer engine 340 executes a process of forming an image on a recording sheet using the raster data for printing generated by the output image processing unit 360.

The output image processing unit 360 processes the image data stored in the memory 320 to generate raster data for printing. When the multifunction device 1 executes a print job, raster data is generated from the image data specified in the print job. Further, in the case of a copy job, raster data is generated from the image data generated by the image reading device 100.

The storage device 106 is a large-capacity, non-volatile storage device such as an HDD (Hard Disk Drive). The storage device 106 is used to store various data related to the operation of the multifunction device 1, for example, screen data to be displayed on the screen of the operation panel 140.

As shown in FIG. 4, the image reading device 100 includes a line light source 210, a drive motor 231 and a line sensor 223, an A / D conversion unit 401, and a barcode processing unit 402. When the line light source 210 receives a light emission command from the CPU 121 included in the controller 300 of the image forming apparatus 120, the line light source 210 emits illumination light upward. As a result, a linear region along the sub-scanning direction is illuminated on the document surface.

The drive motor 231 moves the slider 233 while the line light source 210 emits illumination light, and the reflected light from the document surface passes through the folded mirrors 234, 235, 236 and the optical elements 221 and 222, and the line sensor 223. The line sensor 223 detects the amount of incident light at each sub-scanning position and outputs an analog image signal.

The A / D conversion unit 402 converts the analog image signal output by the line sensor 223 into digital data to generate image data. The generated image data is input to the input image processing unit 310 of the image forming device 120 or the bar code processing unit 402 of the image reading device 100 itself according to the processing type signal from the CPU 301.

The barcode processing unit 402 performs image processing so that the barcode included in the image output by the A / D conversion unit 402 becomes clear, and inputs the processed image data to the input image processing unit 310.
(1-2) Bar code detection operation of the multifunction device 1 Next, the bar code detection operation of the multifunction device 1 will be described.
(1-2-1) Main Routine When the user sets the job content using the operation panel 140 and presses the start key on the operation panel 140, the multifunction device 1 completes the job content setting. Check the settings of. As shown in FIG. 5, when a scan job is accepted from the user (S501: YES), it is determined from the setting contents of the scan job whether or not the scan job is a job for reading a barcode from the smartphone screen. If the barcode is not read from the smartphone screen (S502: NO), after executing the normal reading process (S506), the process proceeds to step S501 and waits for the next job.

If the barcode is read from the smartphone screen (S502: YES), the barcode reading process is executed (S503), the obtained barcode is analyzed (S504), and then the analysis result is output (S505). ), Proceed to step S501 and waits for the next job. The barcode analysis is a process of specifying the width of the white portion or the black portion, or decoding the barcode from the size of the specified width.
(1-2-2) Bar code reading process (S503)
In the barcode reading process, as shown in FIG. 6, first, the line light source 210 is turned off (S601), and then the value of the working variable n is initialized to 1 (S602). Next, with the line light source 210 turned off, the drive motor 241 is rotated to move the slider 233. Then, the emitted light of the smartphone screen of the smartphone 240 mounted on the platen glass 202 is incident on the line sensor 223 via the folding mirrors 234, 235, 236 and the optical elements 221 and 222.

The line sensor 223 detects the amount of incident light at each sub-scanning position and generates an image signal, and the A / D conversion unit 401 digitizes the image signal generated by the line sensor 223 to generate image data, and a bar code processing unit. Input to 402 (S603).

The barcode processing unit 402 adds the input image data to each other (S604). That is, the pixel values of the corresponding pixels of the image data are summed. The total value for each pixel corresponds to the total amount of incident light detected corresponding to the pixel. In the image data, the pixel value of the pixel of the barcode portion includes a barcode component corresponding to the amount of emitted light of the smartphone 240 and a noise component.

The noise component is so-called random noise, and as illustrated in FIG. 7A, the magnitude of the noise component 701 differs between pixels. When the contrast is low compared to the fluctuation range of the size of the noise component 701, such as a barcode displayed on the screen of a smartphone, the pixel value for each pixel is used to make the white part and the black part accurate. It becomes difficult to identify well.

On the other hand, when the average value of the noise component for each pixel matches each other among the pixels, the noise component included in the total value is calculated by summing the pixel values among the pixels corresponding to each other. The total value of the pixel values of is asymptotic even between pixels that do not correspond to each other. Therefore, as illustrated in FIG. 7B, the noise component 702 superimposed on the white pixel and the noise component 703 superimposed on the black pixel have similar magnitudes of the noise component.

Furthermore, as the image data is added, the contrast between the white pixel and the black pixel (difference in pixel value) becomes twice as many as the number of added image data with respect to the contrast of one image, and the contrast is improved. There is also the effect of being done. Therefore, if the addition of image data is repeated, the barcode can be analyzed accurately using the added image.

Aiming at such an effect, when the value of the working variable n is smaller than the predetermined threshold value N (S605: YES), the value of the working variable n is increased by 1 (S606), and the process proceeds to step S603. Proceed and repeat the addition of image data. After that, when the value of the working variable n is smaller than the predetermined threshold value N (S605: YES), the barcode processing unit 402 outputs the added image data to the input image processing unit 310 (S607). , Return to the main routine.

In S607, the barcode processing unit 402 may output the image data after the division after dividing by the number N of the image data obtained by adding the pixel values for each pixel.

By adding the image data in this way, if the noise components are added, the noise components between the added pixels can be made uniform to N times the average value. In particular, when the average value of random noise is 0, it can be made uniform to 0, which is N times the average value, in other words, the noise component can be offset. In addition, the difference in pixel value between the white pixel and the black pixel after addition can be increased.

Therefore, since the white pixel and the black pixel in the barcode can be reliably distinguished, the boundary between the white portion and the black portion can be detected with high accuracy. Then, the width of the striped black lines constituting the barcode and the distance between the adjacent black lines can be accurately specified. Therefore, the barcode data encoded using the width and the distance can be obtained. It can be analyzed with high accuracy.
(1-3) Modification example of the first embodiment The following modification example can be considered for this embodiment.
(1-3-1) First Modification Example In the above embodiment, a case where noise is made uniform and contrast is enhanced by adding a plurality of image data has been described as an example, but this modification has been described. In, the same effect is achieved by using only one image data.

That is, as shown in FIG. 8, in the barcode reading process, after turning off the line light source 210 (S801), reading the smartphone screen and generating image data (S802), adjacent pixels of the same color on the barcode The pixel values are summed together (S803).

In the barcode, as illustrated in FIG. 9, black pixels or white pixels are arranged along the length direction of the striped black line (hereinafter, referred to as “bar direction”). Therefore, if the pixel values are summed between the pixels adjacent to each other in the bar direction, the pixel values can be added to the pixels of the same color. Therefore, the noise component is made uniform by the same mechanism as in the above embodiment, and the white color is obtained. Pixels and black pixels can be reliably distinguished.

Focusing on such characteristics of the barcode, in step S803, the sum of the pixel values of the plurality of pixels continuous along the bar direction is set to the pixel value of any one of the plurality of pixels. For example, among the plurality of pixels, the pixel value of the pixel on the most upstream side in the moving direction of the slider 233 may be used, or the pixel may be the pixel on the most downstream side.

Further, the pixel value of the central pixel of the plurality of pixels continuous in the bar direction may be used. Since the barcode is generally displayed at a position away from the edge of the smartphone screen in the bar direction, the pixel value of the pixel corresponding to the edge of the smartphone screen is calculated in order to calculate the pixel value. Even if the number of pixel values to be totaled is small, it is considered that there is no possibility of causing a problem for the purpose of analyzing the barcode.

Further, the pixels are grouped by a predetermined number from the most upstream side in the moving direction of the slider 233, and the total pixel value of the pixels belonging to the group is set to the pixel value of each pixel belonging to the group for each group. Good. In this way, the number of pixels for which the pixel values are totaled can be made uniform regardless of whether or not it is at the edge of the smartphone screen.

After that, the total value sequence is input to the input image processing unit of the system controller 300 (S804), and the process returns to the main routine. Since the system controller 300 can specify the line width and the interval of the bar in the barcode by referring to the distribution of the white pixel and the black pixel in the total value sequence, the barcode can be analyzed accurately. it can.

Regarding the method of specifying the bar direction, for example, when the user places the smartphone 240 on the platen glass 202, the smartphone 240 is placed so that the bar direction faces in a predetermined direction, or the operation panel 140 is placed. It may be used to force the user to enter the bar direction. Further, the user may be made to specify the display position of the barcode on the smartphone screen by using the operation panel 140.
(1-3-2) Second Modified Example In the above embodiment, a case where a plurality of image data are generated one by one has been described as an example, but it goes without saying that the present disclosure is not limited to this. Instead of, the following may be used.

That is, as shown in FIG. 10, in the barcode reading process, the line light source 210 is turned off (S1001), and the rotation speed of the drive motor 241 is set to 1 / N of the rotation speed in the normal reading process (S1002). .. While setting the rotation speed in this way, the reading speed by the line sensor 223 is set to the same as the normal time, the smartphone screen is read, and image data in which the number of lines in the main scanning direction is N times the normal time is generated ( S1003).

Further, with respect to the image data generated in step S802, the pixel values of N pixels at the same position in the main scanning direction are totaled for each N line from the first line in the sub-scanning direction (S1004) to obtain the image data. The image data is output to the input image processing unit 301 of the system controller 300 (S1005). By doing so, it is possible to obtain image data in which noise is uniformed and contrast is emphasized in the same manner as when N image data are summed up, so that the barcode can be analyzed with high accuracy.
[2] Second Embodiment In the present embodiment, when reading the smartphone screen, the exposure time of the line sensor 223 is extended to improve the contrast. Therefore, the bar code is read with the smartphone placed on the platen glass so that the bar direction of the bar code displayed on the smartphone screen matches the sub-scanning direction of the image reading device 100. Also in the barcode reading process according to the present embodiment, as shown in FIG. 11, the line light source 210 is first turned off (S1101).

In the present embodiment, a CMOS (Complementary Metal Oxide Semiconductor) sensor is used as the line sensor 223, and during normal reading, for example, a reset signal is input every 42 microseconds to detect the exposure amount per pixel. On the other hand, when reading the smartphone screen, the cycle of inputting the reset signal to the CMOS sensor is extended (S1102), and the smartphone screen is read (S1103).

As shown in FIG. 12, when the input cycle of the reset signal of the CMOS sensor 223 is a normal length, the white portion of the barcode printed on plain paper is the amount of reflected light of the illumination light emitted by the line light source 210. There are many. Since the CMOS sensor 223 accumulates charges according to the amount of received light, as shown in FIG. 12, the accumulated charge amount 1201 increases for the pixels corresponding to the white portion of the barcode printed on plain paper.

On the other hand, in the white part of the bar code displayed on the smartphone screen, the display light amount of the smartphone 240 is smaller than the illumination light amount of the line light source 210, so if the exposure time when reading the bar code from plain paper is the same, the exposure time is the same. , The amount of accumulated charge 1202 for the pixel of the CMOS sensor 223 is reduced.

On the other hand, in the bar code reading process according to the present embodiment, the bar direction and the sub-scanning direction are matched, and even if the slider 233 moves, the display light in the white portion continues to be incident on the CMOS sensor 223. Since the reset cycle of the CMOS sensor 223 is extended in this way, the accumulated charge amount 1203 for the pixel of the CMOS sensor 223 is increased without being reset.

For example, if the cycle of inputting the reset signal to the CMOS sensor is set to 10 times the normal period, the exposure time per pixel becomes 10 times, so that the exposure amount per pixel can be increased. Therefore, the difference in pixel values between the white pixels and the black pixels constituting the barcode can also be increased by 10 times to enhance the contrast of the barcode image, so that the barcode image can be analyzed accurately. it can.

In addition, the time required to read one barcode image is the same as the normal time for reading a barcode image from plain paper or the like.
(2-1) Modification Example of the Second Embodiment In the above second embodiment, the user sets the bar direction of the bar code displayed on the smartphone screen to match the sub-scanning direction of the image reading device 100. The smartphone 240 must be placed on the platen glass 202. There is also a problem that the resolution in the sub-scanning direction is lowered.

In response to such a problem, in this modification, as shown in FIG. 13, the reset cycle of the CMOS sensor 223 when reading the barcode from the smartphone screen is set to N times the normal reset cycle (S1302). ), The rotation speed of the drive motor 231 is set to 1 / N times the normal rotation speed (S1303), and the barcode is read (S1304).

By doing so, it is possible to increase the amount of accumulated charge for the pixels corresponding to each position on the smartphone screen, so that the contrast of the barcode image can be improved. Therefore, it is not necessary for the user to limit the direction in which the smartphone 240 is placed on the platen glass 202, and the resolution in the sub-scanning direction does not decrease.
[3] Third Embodiment In the present embodiment, the image reading device 100 reads the barcode image while intermittently moving the display position of the barcode on the smartphone screen in the bar direction, and the barcode image is displayed on the barcode. By summing the pixel values among the pixels corresponding to the same position, the noise component is made uniform and the contrast between the white part and the black part is emphasized.
(3-1) Bar Code Display Processing of Smartphone 240 In the present embodiment, the smartphone 240 is placed on the platen glass 202, and as shown in FIG. 14, the value of the working variable n is first set to 1. Initialize (S1401). Next, the barcode is displayed in the nth display area (S1402). In the example shown in FIG. 15A, when the value of the working variable n is 1, the barcode 1512 is displayed in the display area 1511 on the smartphone screen.

After that, the time required for the reading position of the image reading device 100 to pass the barcode 1512 is set in the timer (S1403), and the elapse of the time is waited for. When the time elapses and a timeout occurs (S1404: YES), the value of the working variable n is compared with the number N of the positions where the barcode is displayed.

As a result of this comparison, if the value of the working variable n is smaller (S1405: YES), the value of the working variable n is increased by 1 (S1406), the process proceeds to step S1402, and the bar is placed at the next position. Display the code. In the example shown in FIG. 15B, when the value of the working variable n is 2, the barcode 1522 is displayed in the display area 1521 on the smartphone screen. The image reading device 100 moves the slider 233 to read the barcode 1522.

After that, when the value of the working variable n reaches the number N and the reading of the Nth barcode is completed (S1405: NO), the process ends.

The smartphone 240 needs to operate at the same timing as the image reading device 100. Therefore, the smartphone 240 detects that the image reading device 100 has turned off the line light source 210 by using the in-camera provided on the display screen side, and immediately after the line light source 210 is turned off, or a predetermined time elapses. After that, the bar code display (S1402) may be started.
(3-2) Bar Code Reading Process of Image Reading Device 100 As shown in FIG. 16, the image reading device 100 turns off the line light source 210 (S1601), reads N bar codes, and generates image data. (S1602). The image data 1531 illustrated in FIG. 15C is image data including N barcodes 1532.

Next, N barcode images including only one barcode are cut out from the generated image data (S1603). The position (separation position) of the cutout line 1533 for cutting out N image data from the image data 1531 including N barcodes is set in advance. The image reading device 100 cuts out N image data by cutting out the image data at the position of the cutout line 1533.

Further, the added image data obtained by summing the N cut-out image data is generated (S1604), and the obtained image data is output (S1605). Even in this way, the noise component superimposed on the barcode image can be made uniform and the contrast of the barcode image can be emphasized, so that the barcode can be analyzed with high accuracy.

Instead of displaying N barcodes on the smartphone screen in sequence, all N barcodes may be displayed on the smartphone screen, and the same effect can be obtained in this way.
(3-3) Modification Example of Third Embodiment In the above-mentioned third embodiment, a case where a barcode is displayed at N positions has been described as an example, but instead of this, the slider 233 The barcode may be read while continuously moving the barcode in the bar direction (sub-scanning direction) at a speed slower than the moving speed.

As illustrated in FIG. 17A, the barcode 1712 is displayed in the display area 1711 on the smartphone screen, and the image reading device 100 moves the barcode in the sub-scanning direction, which is the moving direction of the slider 233. Read.

Then, as illustrated in FIG. 17B, the length of the barcode image 1721 in the sub-scanning direction changes according to the difference between the moving speed of the barcode and the moving speed of the slider 233. In particular, as the moving speed of the barcode on the smartphone screen is slower than the moving speed of the slider 233, the barcode image 1721 is enlarged in the sub-scanning direction.

As a result, when the length of the barcode image in the sub-scanning direction becomes N times the barcode displayed on the smartphone screen, N lines from the upstream side in the sub-scanning direction are read in the main scanning direction. Group. Then, the pixel values of the pixels corresponding to each other in the lines belonging to the same group are summed using the adder 1731.

Since the bar code image 1741 generated in this way also homogenizes the noise component and emphasizes the contrast, the bar code can be analyzed with high accuracy.
[4] Modified Examples Although the present disclosure has been described above based on the embodiments, it goes without saying that the present disclosure is not limited to the above-described embodiments, and the following modified examples can be implemented. ..
(4-1) The determination as to whether or not to execute the barcode reading process is performed, for example, as shown in FIG. 18, when the user sets the content of the scan job using the operation panel 140, the barcode reading mode. When is selected (S1801: YES), the process may shift to the barcode reading process (S1802).

As another method, as shown in FIG. 19, the line light source 210 is first turned off (S1901), the image is read, and image data is generated (S1902). Next, each pixel of the generated image data is binarized according to whether or not the pixel value is larger than a predetermined threshold value (S1903), and the number of white pixels having a pixel value of 1 in the binarized image is counted. (S1904).

If the number of white pixels is larger than the predetermined number (threshold value) (S1905: YES), it is determined that the barcode image is displayed on the smartphone screen that emits light by itself without irradiating the illumination light. , Shift to the barcode reading process (S1906).

When the number of white pixels is less than or equal to a predetermined number (threshold value) (S1905: NO), plain paper or the like does not emit light by itself, and therefore it is dark unless illuminated with a line light source 210, and the pixel value decreases. Since it is determined that the image is being read from, the line light source 210 is turned on and a normal reading process is executed.

When the number of white pixels is larger than the predetermined number (threshold value) (S1905: YES), the rectangular area having the same area and shape as the bar code is moved on the binarized image. The number of black pixels is counted for each region, and it is confirmed whether or not the number of black pixels is larger than a predetermined number (a threshold value set separately from the threshold value of the number of white pixels).

It is considered that the rectangular area including the barcode has black pixels concentrated in the rectangular area as compared with the rectangular area not including the barcode. Therefore, only when the number of black pixels is larger than the threshold value, it may be determined that the rectangular area contains the barcode, and the process may shift to the barcode reading process.

Since it does not emit light by itself such as plain paper, it is dark unless it is illuminated with a line light source 210, and the number of black pixels tends to increase when the image read from a medium whose pixel value decreases is binarized. Therefore, if the number of white pixels is compared with the threshold value to confirm that the screen is displayed and then the number of black pixels is counted, the barcode is read only when the barcode image is displayed on the screen. You can move to processing.
(4-2) In the above embodiment, the case where the image forming apparatus is a multifunction device has been described as an example, but it goes without saying that the present disclosure is not limited to this, and instead, a copying apparatus, a facsimile apparatus, etc. , It may be a single-function device including the image reading device 100. Further, even if the automatic document transporting device 110 is not provided, the above-mentioned effects can be obtained by applying the present disclosure.
(4-3) In the above embodiment, the case of reading the barcode displayed on the smartphone screen has been described as an example, but it goes without saying that the present disclosure is not limited to this, and other than the smartphone 240 such as a tablet terminal is possible. The barcode displayed on the portable terminal device may be read. If the barcode displayed on the screen is read by emitting light, the effect can be obtained by applying the present disclosure.
(4-4) In the above embodiment, the case where the line light source 210 is turned off when reading the barcode displayed on the smartphone screen has been described as an example, but it goes without saying that the present disclosure is not limited to this. Instead of this, the barcode may be read from the smartphone screen with the line light source 210 turned on. The same effect can be obtained by applying the present disclosure when the line light source 210 is turned on.

The image reading device and the image forming device according to the present disclosure are useful as devices capable of reading the barcode displayed on the screen with high accuracy.

1 ... Image forming device 100 ... Image reading device 202 ... Platen glass 210 ... Line light source 223 ... Line sensor 233 ... Slider 240 ... Smartphone 241 ... Bar code

Claims (14)

When reading with the platen set method, the lighting means to illuminate the reading target and
A light receiving amount detecting means for detecting the light receiving amount from the reading target while moving together with the lighting means along the reading surface of the reading target.
An image forming apparatus comprising a conversion means for converting the detected light receiving amount into a pixel value.
A reading target determining means for determining whether or not the reading target is a barcode displayed on the display screen of the portable device, and
When the determination is affirmative, the white portion and the black portion of the barcode are formed by performing at least one of the control of the light receiving amount detecting means and the image processing for changing the pixel value obtained by the conversion. An image forming apparatus comprising: a bar code reading control means for expanding the difference in pixel values between pixels and averaging noise components contained in the pixel values after the image processing among the pixels. .. The image forming apparatus according to claim 1, further comprising a light-off means for turning off the lighting means when it is determined that the reading target is a barcode displayed on a display screen. The reading target determination means is
A reception means for accepting designation as to whether or not the read target is a barcode is provided.
The image forming apparatus according to claim 1 or 2, wherein the determination of the reading target is executed according to the designation received by the receiving means. The reading target determination means is
A concentration area determination means for determining whether or not there is a concentration area in which pixels whose pixel values obtained by the conversion are equal to or greater than a predetermined threshold value are concentrated is provided.
The image forming apparatus according to claim 1 or 2, wherein when it is determined that there is a concentrated area, it is determined that the reading target is a barcode. The barcode reading control means is used in the image processing.
The difference between the pixel values is increased by adding the pixel values between the pixels estimated to be the same color from the position on the image data and making the obtained pixel value the pixel value corresponding to the pixel set. The image forming apparatus according to any one of claims 1 to 4. The barcode reading control means is
The operation of detecting the light receiving amount while moving the light receiving amount detecting means from the reading start end to the reading end end along the platen glass is repeated a plurality of times.
The image forming apparatus according to claim 5, wherein pixels at the same position among the obtained plurality of image data are estimated as pixels of the same color, and the pixel values are added. When the reading target is placed on the platen glass in a state where the bar direction of the barcode coincides with the moving direction of the light receiving amount detecting means.
Pixels that are continuous along the bar direction are estimated to be pixels of the same color, and the pixel values are added to obtain the pixel values of pixels that are at the same position as the continuous pixels in the direction orthogonal to the bar direction. The image forming apparatus according to claim 5. The barcode reading means is
By controlling the light receiving amount detecting means and reducing the moving speed thereof, the same line orthogonal to the bar direction in the barcode is read a plurality of times.
The image forming apparatus according to claim 5, wherein a plurality of pixels corresponding to the same position on the same line are estimated as pixels of the same color, and the pixel values are added. The barcode reading means is
By controlling the light receiving amount detecting means to lengthen the exposure time for detecting the light receiving amount of one pixel as compared with the case where it is determined that the reading target is not the bar code displayed on the screen, the pixel value is determined. The image forming apparatus according to any one of claims 1 to 4, wherein the difference is enlarged. When the reading target is placed on the platen glass so that the bar direction of the barcode coincides with the moving direction of the light receiving amount detecting means.
The barcode reading means is
It is characterized in that the difference in pixel values is increased by detecting the amount of light received as one pixel in a wide range in the bar direction, as compared with the case where it is determined that the reading target is not the bar code displayed on the screen. The image forming apparatus according to claim 9. The barcode reading means is
The light receiving amount detecting means according to the ratio of the exposure time when it is determined that the reading target is not the screen-displayed barcode to the exposure time when it is determined that the reading target is not the screen-displayed barcode. The image forming apparatus according to claim 9, wherein the moving speed of the image forming apparatus is reduced. When the barcode is displayed to move along the moving direction of the received light amount detecting means at the time of reading.
The barcode reading control means is
The pixel values obtained by adding the pixel values of the pixels whose light receiving amounts are detected at different positions in the moving direction of the light receiving amount detecting means and at the corresponding positions on the image data are obtained. The image forming apparatus according to any one of claims 1 to 4, wherein the difference between the pixel values is increased by setting the pixel value of the pixel corresponding to the position. When the movement of the barcode along the movement direction intermittently moves to a plurality of positions.
The barcode reading means is
An image dividing means for dividing the barcodes displayed at the plurality of positions on the scanned image at the dividing positions and dividing the barcodes into a plurality of partial images.
The image forming apparatus according to claim 12, further comprising an image adding means for adding pixel values of pixels at corresponding positions among the plurality of partial images. When the barcode continuously moves at a speed slower than the moving speed of the received light amount detecting means.
Among the lines orthogonal to the bar direction on the barcode, an image dividing means for dividing the scanned image into a plurality of partial images at a dividing position for dividing adjacent lines in the bar direction.
The twelfth claim is characterized in that each partial image is provided with an image adding means for adding pixel values between pixels continuous in the bar direction to obtain pixel values of pixels corresponding to positions on the line. The image forming apparatus according to.

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