Image scanning apparatus

An image scanning apparatus includes a transport roller transporting an original, a CCD scanning a first side of the original, a CIS scanning unit scanning a second side of the original, and a flap for reversing the original and sending the original to a transport path. A CPU controls the transport roller, the CCD and the CIS scanning unit to scan each side of the original. The CPU determines from the result of scanning whether or not each side of the original includes a predetermined pattern. When the CPU cannot identify from the result of scanning of the second side whether or not the second side includes a predetermined pattern, the CPU controls the flap and a transport unit to reverse the original and cause the CCD to scan the second side.

This application is based on Japanese Patent Application No. 2008-158229 filed with the Japan Patent Office on Jun. 17, 2008, the entire content of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image scanning apparatus scanning an original to detect a predetermined pattern included in the original.

2. Description of the Related Art

In recent years, for the purpose of preventing unauthorized copy of an original, an image scanning apparatus having bill recognition capability or security screen pattern capability has been developed.

The bill recognition is a technology of determining whether or not an original is a special one such as bill or valuable paper. The bill recognition is generally achieved by examining whether or not image data obtained by scanning an original includes a specific pattern.

Further, the security screen pattern is a technology of printing in advance, on an original image, a character string or the like such as “copy prohibited” as a screen pattern that reappears on a copy of the original. The security screen pattern can prevent unauthorized copy of a confidential document. Japanese Laid-Open Patent Publication No. 2005-142917 discloses an image processing apparatus that determines, based on the dot density of image data, whether or not the image data obtained by scanning an original with a scanner is a confidential document.

The image scanning apparatus thus scans an original to determine whether or not the original includes a pattern specific to a bill or a predetermined pattern such as screen pattern. The image scanning apparatus can use the result of the determination to prevent unauthorized copy of the original.

Consideration will be given here to an original whose opposing two sides are both printed with respective images. It is supposed that, if at least one side of the original is printed with a predetermined pattern as described above, the images on the opposing two sides are intended to be prevented from being copied unauthorizedly. Actually, however, an apparatus scanning only one side of the original can scan the side without the predetermined pattern. Therefore, in order to surely determine whether or not the original includes the predetermined pattern, it is necessary to scan both sides of the original.

A method for scanning both sides of an original is to combine one-side scanning and reversal of an original.

Another method for scanning both sides of an original is to use an image scanning apparatus including two scanning units (first scanning unit and second scanning unit). According to this method, the image scanning apparatus scans a first side of the original using the first scanning unit, and scans a second side of the original using the second scanning unit. This method is hereinafter referred to as simultaneous double-side scanning. The simultaneous double-side scanning requires a large-sized apparatus including two image scanning units. The simultaneous double-side scanning, however, can shorten the time required for scanning. The simultaneous double-side scanning is therefore widely used.

Some image scanning apparatuses for use in simultaneous double-side scanning include a scanning unit configured with a combination of a CCD (Charge-Coupled Device) and a CIS (Contact Image Sensor).

The CCD scans, via a reduction optical system, the light that is emitted from a light source such as halogen lamp or xenon bulb lamp to an original and reflected from the original. The CIS scans the light emitted from an LED (Light Emitting Diode) light source to an original where the size of the scan light is identical to the original size.

Scanning with the CIS is shallower in depth of field as compared with scanning with the CCD, resulting in an out-of-focus state even when the fed original is displaced to a slight degree. Thus, the accuracy of scanning with the CIS is low. In the case of scanning with the CCD, however, an optical system has to be provided between an original and the CCD. Thus, scanning with the CCD has a disadvantage that a large space is necessary. Both the high scanning accuracy and the downsizing of the apparatus can be accomplished by combining the CIS scanning and the CCD scanning.

Japanese Laid-Open Patent Publication No. 2007-074500 discloses an image scanning apparatus having an original reversal mechanism. The image scanning apparatus disclosed in Japanese Laid-Open Patent Publication No. 2007-074500 includes a CCD scanning unit and a CIS scanning unit. The CCD scanning unit can scan both of a monochrome image and a color image. While the CIS scanning unit can scan a monochrome image only, the CIS scanning unit can determine whether a scan image is a monochrome image or color image. Only in the case where the image scanned by the CIS scanning unit is a color image, the image scanning apparatus reverses the original and scans the original again. In this way, the image scanning apparatus can efficiently scan a plurality of originals including a color image and a monochrome image.

Japanese Laid-Open Patent Publication No. 2005-012442 discloses an image scanning apparatus performing the simultaneous double-side scanning with a CCD and a CIS in a speed-priority mode. This image scanning apparatus scans the front side and the rear side of an original using the CCD in an image-quality-priority mode.

If the simultaneous double-side scanning technology by means of the CIS and CCD in combination is directly applied, it may not be accurately determined whether or not an original includes a predetermined pattern, because the accuracy of scanning with the CIS and the accuracy of scanning with the CCD differ from each other.

SUMMARY OF THE INVENTION

The present invention has been made to solve the problems above. A main object of the present invention is to provide an image scanning apparatus scanning an original with two different types of scanning apparatuses with respective scanning accuracies different from each other, and capable of highly accurately determining whether or not the original includes a predetermined pattern.

According to an aspect of the present invention, an image scanning apparatus is provided. The image scanning apparatus includes a first scanner, a second scanner, a determination unit, and a control unit. The first scanner scans a first side of an original with a first scanning accuracy to generate first image data. The second scanner scans a second side of the original with a second scanning accuracy lower than the first scanning accuracy to generate second image data. The determination unit determines whether or not each of the first image data and the second image data includes a predetermined pattern. The control unit causes the first scanner to scan the second side when the determination unit determines that whether the second image data includes the predetermined pattern is indeterminate.

Preferably, the determination unit includes a calculation unit calculating a degree to which each of the first and the second image data includes the predetermined pattern. The determination unit determines, based on the degree, whether or not each of the first image data and the second image data includes the predetermined pattern. The control unit controls the first scanner such that the first scanner scans the second side when the degree of the second image falls within a predetermined range.

More preferably, the determination unit determines that the first image data includes the predetermined pattern when the degree of the first image data exceeds a first criterion. The determination unit determines that the first image data does not include the predetermined pattern when the degree of the first image data does not exceed the first criterion. The determination unit determines that the second image data includes the predetermined pattern when the degree of the second image data exceeds a second criterion. The determination unit determines that the second image data does not include the predetermined pattern when the degree of the second image data does not exceed a third criterion.

More preferably, a value of the first criterion is not less than the third criterion and not more than the second criterion.

Preferably, when the determination unit determines that the first image data includes the predetermined pattern, the control unit keeps the first scanner from scanning the second side regardless of a result of determination for the second side by the determination unit.

More preferably, the predetermined pattern is a pattern representing prohibition of output of image data. When the determination unit determines that the first image data or the second image data includes the predetermined pattern, the control unit prohibits output of respective images corresponding to the first image data and the second image data.

More preferably, the predetermined pattern is a pattern for identifying the original as a bill.

Preferably, when the determination unit determines that the first image data does not include the predetermined pattern, the control unit keeps the first scanner from scanning the second side regardless of a result of determination for the second side by the determination unit.

More preferably, the predetermined pattern is a pattern representing permission of output of the first image data and the second image data. When the determination unit determines that neither the first image data nor the second image data includes the predetermined pattern, the control unit prohibits output of respective images corresponding to the first image data and the second image data.

Preferably, the image scanning apparatus further includes a transport unit transporting the original, and a reversal unit reversing the original when the original whose second side is scanned by the second scanner is transported to the first scanner by the transport unit. The control unit causes the first scanner to scan the second side by controlling the transport unit and the reversal unit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described hereinafter with reference to the drawings. In the following description, like components are denoted by like reference characters. The components are named identically and function identically as well. Therefore, a detailed description thereof will not be repeated.

First Embodiment

FIG. 1is a schematic diagram of an image processing apparatus100according to the present embodiment. Image processing apparatus100includes an image scanning apparatus102and a print unit150. Image scanning apparatus102includes an upper unit110, an original tray120, an original catch tray130, and a lower unit140. Print unit150includes a plurality of paper feed trays152and a catch tray154.

On original tray120, an original to be transported to upper unit110is set. Onto original catch tray130, the original is ejected from upper unit110.

Details of image scanning apparatus102will be described now with reference toFIG. 2.FIG. 2is a cross section of image scanning apparatus102.

Upper unit110includes transport rollers202-212, a CIS scanning unit220, a member230, and a flap240.

Transport rollers202-212each transport the original which is set on original tray120, and finally eject the original onto original catch tray130.

CIS scanning unit220applies LED (Light Emitting Diode) light to the original. CIS scanning unit220also detects the LED light reflected from the original. Further, CIS scanning unit220generates image data (hereinafter scan data) according to the result of the detection.

Member230presses the original against CIS scanning unit220while transporting the original. Flap240switches the transport path of the original carried by transport roller211and transport roller212into the transport path so as to turn the original upside down.

Lower unit140includes a transparent platen250, a movable stage260, a light source265, a first mirror270, a second mirror272, a third mirror274, a CCD280, and a processing unit290. Light source265and first mirror270are placed on movable stage260.

The original is placed on platen250. Movable stage260moves under platen250in the direction indicated by the arrow in the drawing. Light source265applies light to the original. First mirror270receives the light reflected from the original. First mirror270, second mirror272and third mirror274are arranged in such a manner that directs the light from the original to CCD280. CCD280detects the light reflected from the original to generate scan data according to the result of the detection.

Processing unit290includes a CPU (Central Processing Unit)292, a RAM (Random-Access Memory)294, a ROM (Read-Only Memory)296, and a flash memory298.

CPU292controls the operation of each component of image processing apparatus100. RAM294stores temporary data generated while CPU292executes a process. ROM296stores a program or the like for controlling image processing apparatus100. Flash memory298stores image data such as scan data scanned by a scanning unit, a determination level used when a determination is made as to whether or not an original includes a predetermined pattern, a reference pattern used as a reference for the determination, and set values or the like for the copy such as the number of copies to be made and sheet size.

It is supposed here that CPU292, RAM294, ROM296, and flash memory298are included in lower unit140. The locations where these components are provided, however, are not limited to the inside of lower unit140.

Referring back toFIG. 1, print unit150prints the scanned original on a recording medium such as a sheet of paper supplied to paper feed tray152. Namely, print unit150prints an image on a sheet of paper, based on the scan data that are output respectively from CIS scanning unit220and CCD280. Print unit150also exits the sheet of paper printed with the image to catch tray154.

FIG. 3is a top view of image processing apparatus100. Referring toFIG. 3, an operation panel310, an input key set320and a start key330are disposed on the top surface of lower unit140.

Operation panel310receives an instruction of a user. Operation panel310also displays various information that can be set by the user for image processing apparatus100, such as output condition settings. Input key set320includes for example numerical keys and a clear key. As an input key320is pressed down, a set value such as an output condition is input to image processing apparatus100. As start key330is pressed down, image processing apparatus100starts printing image data according to the input set value.

FIG. 4is a diagram showing an example of the display screen of operation panel310. Operation panel310indicates a copy type area410, a paper size area420, a copy number area430, a scale area440, a density area450, and a scan condition setting area460. As a user touches a portion corresponding to each area on operation panel310, the area is selected.

When copy type area410is selected, operation panel310indicates a screen for allowing the user to select color printing or monochrome printing. As the user performs an operation, for example, touches operation panel310, the copy type is determined as color copy or monochrome copy. The screen indicated on operation panel310when copy type area410is selected may naturally include an indication for setting other copy types.

When paper size area420is selected, operation panel310indicates a screen for allowing the user to select a paper size. As the user performs an operation, for example, touches operation panel310, the paper size is determined.

When copy number area430is selected, operation panel310indicates a screen for allowing the user to input the number of copies to be made. As the user performs an operation, for example, touches operation panel310, or presses a numerical key(s) of input key set320, the number of copies is determined.

When scale area440is selected, operation panel310indicates a screen for allowing the user to select (input) the scale or degree of enlargement/reduction of an output image relative to the original. As the user performs an operation, for example, touches operation panel310, the scale is determined.

When density area450is selected, operation panel310indicates a screen for allowing the user to select an output density setting. As the user performs an operation, for example, touches operation panel310, the density is determined.

When scan condition setting area460is selected, operation panel310indicates a screen for allowing the user to select a scanning condition of the original. As the user performs an operation, for example, touches operation panel310, the scan condition is determined.

Regarding the image processing apparatus in the present embodiment, the scan condition includes, in addition to the resolution or the like, a determination level. The determination level is used when CPU292determines whether a scanned original is a bill or the scanned original includes security information such as a screen pattern. Details of the determination level will be described hereinlater.

FIG. 5is a block diagram showing a functional configuration of image processing apparatus100. Referring toFIG. 5, the functional configuration of image processing apparatus100will be described below.

Image processing apparatus100includes an input unit510, a control unit520, a transport unit530, a reversal unit540, an image scanning unit550, a storage unit560, a display unit570, a print unit580, an image facsimile transmission and reception unit590, and a network connection unit595.

Input unit510receives an instruction given from the outside. In the present embodiment, operation panel310, input key set320and start key330correspond to input unit510.

Control unit520controls the operation of image processing apparatus100based on the instruction received by input unit510or the like. In the present embodiment, CPU292corresponds to control unit520. Each function of control unit520may be implemented by hardware.

Control unit520includes a scan control unit522, a level setting unit524, a print setting unit526, and a determination unit528. Determination unit528has a pattern matching unit529.

Scan control unit522controls transport unit530and image scanning unit550based on an instruction so as to scan the original. Further, when it cannot be determined whether image data on a side scanned by CIS scanning unit220in the first scanning operation includes a predetermined pattern, scan control unit522controls transport unit530, reversal unit540and image scanning unit550so that image scanning unit550scans the original again.

Level setting unit524sets a determination level564used for determining whether or not the original includes a predetermined pattern, based on an instruction.

Print setting unit526sets various information such as output condition at print setting568in storage unit560.

Pattern matching unit529calculates the rate of agreement with (or rate of detection of) a reference pattern566of scan data562. Determination unit528determines whether or not the original includes reference pattern566based on the rate of agreement (or rate of detection) as well as determination level564, and outputs the result of the determination to print unit580. Details of reference pattern566, the rate of agreement and the rate of detection will be described hereinlater.

Transport unit530transports the original. In the present embodiment, transport rollers202-212each and member230correspond to transport unit530. It should be noted that the component(s) used as transport unit530is not limited to them.

Reversal unit540turns the original upside down in the transport path. In the present embodiment, flap240, transport roller211and transport roller212correspond to reversal unit540.

Image scanning unit550scans the original to output scan data562to storage unit560. Image scanning unit550includes a first scanning unit552and a second scanning unit554. It is supposed here that the accuracy in scanning the original by first scanning unit552is higher than the accuracy in scanning the original by second scanning unit554. In the present embodiment, movable stage260, light source265, first mirror270, second mirror272, third mirror274, and the CCD scanning unit configured with CCD280correspond to first image scanning unit552. CIS scanning unit220corresponds to second image scanning unit554.

Storage unit560stores scan data562, determination level564, reference pattern566, and print setting568. Reference pattern566is used for determining whether or not scan data562includes a bill or screen pattern (security information). Reference pattern566includes a bill pattern566a, and a screen pattern (security pattern)566bused for detecting a screen pattern (security information). In the present embodiment, RAM294, ROM296and flash memory298correspond to storage unit560. Display unit570indicates information concerning the inside of image processing apparatus100such as print setting568. In the present embodiment, operation panel310corresponds to display unit570.

Print unit580prints, on a sheet of paper, an image based on scan data562, according to the result of the determination of determination unit528. Print unit580includes an image forming unit582and an image output unit584.

Image forming unit582generates image data (hereinafter referred to as output data) based on the result of the determination by determination unit528and print setting568.

When image forming unit582receives the result of the determination that copy is to be permitted, image forming unit582performs image processing or the like based on the output condition set at print setting568for scan data562, and generates output data. Image forming unit582generates such output data when, for example, it is determined that the original is not a bill, what is represented by a detected screen pattern indicates permission of copy, or a screen pattern indicating prohibition of copy is not detected from scan data.

When image forming unit582receives the result of the determination that copy is to be prohibited, image forming unit582does not generate the output data. Alternatively, image forming unit582may generate the output data such that characters such as “copy prohibited” overlap scan data562. Image forming unit582generates such output data when, for example, it is determined that the original is a bill, or what is represented by the detected screen pattern indicates that copy is to be prohibited.

Image output unit584prints the output data generated by image forming unit582on a sheet of copy paper. Image output unit584may print the output data on a recording medium except for paper, such as film for example.

Facsimile transmission and reception unit590transmits facsimile data to another apparatus. Facsimile transmission and reception unit590also receives facsimile data from another apparatus. Network connection unit595connects image processing apparatus100and another apparatus by network.

Image processing apparatus100according to the first embodiment is used for bill recognition. A process performed by image processing apparatus100according to the first embodiment will be described in the following.

Image processing apparatus100according to the present embodiment calculates, for bill recognition, the rate of agreement of scan data562obtained by CIS scanning unit220or CCD280with bill pattern566a. A higher rate of agreement can be regarded as indicating a greater resemblance to a bill. Therefore, image processing apparatus100determines that an original is a bill when the rate of agreement is equal to or higher than the set determination level564. When the rate of agreement is not higher than determination level564, image processing apparatus100determines that the original is not a bill.

In the present embodiment, determination level564that is used when it is determined whether or not an original is a bill based on scan data562obtained by CIS scanning unit220, and determination level564that is used when it is determined whether or not an original is a bill based on scan data562obtained by CCD280are different from each other, which will be described with reference toFIG. 6.FIG. 6is a diagram illustrating determination level564in the first embodiment.

Determination unit528determines, based on a first determination level, whether or not scan data562obtained by CCD280agrees with bill pattern566a, and accordingly determines whether the original is a bill or not.

Specifically, when the rate of agreement of scan data562obtained by CCD280with bill pattern566ais equal to or higher than the first determination level (hereinafter referred to Level 1), determination unit528determines that the original is a bill. When the rate of agreement is lower than Level 1, determination unit528determines that the original is not a bill.

Here, “rate of agreement” refers to a measure representing to what degree a face of an original agrees with a bill. Specifically, “rate of agreement” refers to the rate of agreement of a predetermined pattern included in scan data562as scanned, with bill pattern566a.

In contrast, determination unit528uses a second determination level and a third determination level when determination unit528determines whether or not an original is a bill based on scan data562obtained by CIS scanning unit220. It is supposed hereinafter that the value of the second determination level is “Level 2” and the value of the third determination level is “Level 3.”

When the rate of agreement of scan data562obtained by CIS scanning unit220with bill pattern566ais equal to or higher than Level 2, determination unit528determines that the original is a bill. When the rate of agreement is equal to or lower than Level 3, determination unit528determines that the original is not a bill. When the rate of agreement is between Level 2 and Level 3, determination unit528cannot determine whether the original is a bill or not. In other words, when the rate of agreement is between Level 2 and Level 3, determination unit528determines that whether the side of the original scanned by CIS scanning unit200includes bill pattern566ais indeterminate.

Here, Level 2 is a value indicating a higher rate of agreement than Level 1. Further, Level 3 is a value indicating a lower rate of agreement than Level 1. The scanning accuracy of the CIS is lower than the scanning accuracy of the CCD. Therefore, the determination level value Level 2 used for determining that an original is surely a bill is set higher than Level 1. Further, the determination level value Level 3 used for determining that an original is surely not a bill is set lower than Level 1.

Referring toFIG. 7, a process performed by image processing apparatus100according to the first embodiment will be described.FIG. 7is a flowchart showing the process performed by image processing apparatus100according to the first embodiment.

In step S701, CPU292controls transport roller202for example to transport an original.

In step S703, CPU292controls CIS scanning unit220, CCD280and movable stage260for example to scan both sides of the original. CPU292causes CCD280to scan the upward-facing side (hereinafter referred to as front side) of the original set on original tray120. Further, CPU292causes CIS scanning unit220to scan the side facing downward when set on original tray120(the side is hereinafter referred to as rear side).

In step S705, CPU292calculates the rate of agreement of scan data562obtained by CCD280with bill pattern566aby means of pattern matching. CPU292then regards the calculated rate of agreement as a resemblance of the front side to a bill and determines whether or not the resemblance of the front side to a bill is less than Level 1.

It is supposed in the present embodiment that image processing apparatus100uses bill pattern566aof only one side even when the apparatus is to recognize a duplex-printed bill such as Japanese bills. It should be noted that image processing apparatus100may store respective patterns of the two sides of a bill in storage unit560and determine whether or not the front side of an original scanned by CCD280agrees with the front side or rear side of the bill so as to authenticate the bill. The configuration as described above, however, requires a large storage capacity for storing the patterns of the two sides of a bill.

When the resemblance of the front side to a bill is not less than Level 1 (NO in step S705), CPU292causes in step S707print unit150to cancel output of an image. This is for the reason that, when it is determined that the resemblance of scan data562obtained by CCD280to a bill is equal to or higher than Level 1, it is highly likely that the original is a bill. Through this process, image processing apparatus100can skip the steps from step S709for determining the resemblance of the rear side to a bill. In this way, the speed of the process performed by image processing apparatus100can be increased.

When the resemblance of the front side to a bill is less than Level 1 (YES in step S705), CPU292performs pattern matching in step S709between scan data562obtained by CIS scanning unit220and bill pattern566a. CPU292then regards the rate of agreement of scan data562obtained by CIS scanning unit220with bill pattern566aas the resemblance of the rear side to a bill, and determines whether or not the resemblance of the rear side to a bill is less than Level 2.

When the resemblance of the rear side to a bill is not less than Level 2 (NO in step S709), CPU292causes print unit150to cancel output of an image in step S707, since it is seen that the original is highly likely to be a bill when the result of the determination as to the rear side is the one as described above.

When the resemblance of the rear side to a bill is less than Level 2 (YES in step S709), CPU292determines in step S711whether or not the resemblance of the rear side to a bill is equal to or less than Level 3.

When the resemblance of the rear side to a bill is equal to or less than Level 3 (YES in step S711), both of the front side and the rear side do not agree with the bill pattern. In other words, the original is not a bill. In this case, CPU292causes print unit150to output an image in step S713.

When the resemblance of the rear side to a bill is not equal to or less than Level 3 (NO in step S711), the resemblance of the rear side to a bill is between Level 2 and Level 3. Therefore, CPU292cannot determine that the rear side is a bill, and cannot determine that the rear side is not a bill. CPU292then performs the following steps to reverse the original and cause CCD280with a higher scanning accuracy to scan the rear side, and determines the resemblance of the rear side to a bill, based on the scan data.

In step S715, CPU292uses transport roller211, transport roller212and flap240to reverse the original and return the original back to the transport path.

In step S719, CPU292causes CCD280to scan the rear side of the original.

In step S721, CPU292performs pattern matching between scan data562obtained by CCD280and bill pattern566a. CPU292then regards the rate of agreement of scan data562with bill pattern566aas the resemblance of the rear side to a bill, and determines whether the resemblance of the rear side to a bill is less than Level 1.

When the resemblance of the rear side to a bill is less than Level 1 (YES in step S721), the original can be regarded as not a bill, and thus CPU292can cause print unit150to output an image in step S713.

When the resemblance of the rear side to a bill is not less than Level 1 (NO in step S721), it is highly likely that the rear side of the original is bill data, namely the original is highly likely to be a bill. In this case, CPU292causes print unit150to cancel output of an image in step S707.

In other words, image processing apparatus100according to the present embodiment causes the original to be scanned again when the rate of agreement of scan data562obtained by the CIS with a predetermined bill pattern is within a predetermined range including the determination level used for the determination as to the scan data obtained by the CCD. Image processing apparatus100thus operates in the above described manner to reduce the number of reversal operations and improve the scan accuracy.

An example has been described above where two determination levels are used for determining whether or not an original is a bill based on scan data562obtained by CIS scanning unit220. CPU292, however, may use only one determination level to determine whether or not an original is a bill, based on scan data562obtained by CIS scanning unit220. For example, in the case where CPU292uses only the determination level of Level 3 to recognize a bill, the operation in step S709ofFIG. 7is skipped.

It should be noted that in the case where the two determination levels are used like the present embodiment, the rate of agreement between an original and a bill can be determined with a higher accuracy.

While the case where image processing apparatus100is used for bill recognition has been described above, image processing apparatus100according to the present embodiment may be used for recognition of a special original whose copy is prohibited such as valuable paper and postage stamp, in addition to recognition of a bill. Further, image processing apparatus100may use screen pattern566brepresenting information that copy is prohibited, instead of bill pattern566a. In this case, image processing apparatus100can prevent unauthorized copy of an original provided with security screen pattern.

Second Embodiment

Image processing apparatus100according to the first embodiment prohibits copy when a predetermined pattern is detected on either the front side or the rear side.

Image processing apparatus100in a second embodiment prohibits copy when a predetermined pattern is not detected on either the front side or the rear side. In other words, image processing apparatus100permits copy only when a predetermined pattern is detected on the front side and the rear side. In particular, a description will be given here supposing that the predetermined pattern is a screen pattern representing information “copy permitted.”

The hardware configuration and the functional configuration of image processing apparatus100in the second embodiment are substantially identical to those of the first embodiment. Therefore, the description thereof will not be repeated. It should be noted that the process performed by determination unit528differs from that of the first embodiment as described below.

Determination unit528of image processing apparatus100in the second embodiment determines whether or not a screen pattern that agrees with screen pattern566bis embedded in an original.

Determination unit528makes a comparison between the rate of detection of the screen pattern in the image data which is obtained by scanning the original and determination level564to determine whether or not the screen pattern is embedded in the original.

Determination level564used in the second embodiment will be described with reference toFIG. 8.FIG. 8is a diagram illustrating determination level564in the second embodiment.

Determination unit528determines whether or not an original scanned by the CCD includes a screen pattern based on a first determination level564. The value of first determination level564is hereinafter referred to as “Level 1.” When the rate of detection of the screen pattern in the scan data obtained by scanning with the CCD system is equal to or higher than Level 1, determination unit528determines that the original includes the screen pattern. When the rate of detection is less than Level 1, determination unit528determines that the original does not include the screen pattern.

In contrast, when the rate of detection of the screen pattern in the scan data obtained by scanning with the CIS is equal to or higher than Level 2 that is a second determination level, determination unit528determines that the original includes the screen pattern. When the rate of detection is less than Level 2, determination unit528determines that whether or not the original includes the screen pattern cannot be identified. Here, Level 2 is set higher than Level 1, since the accuracy of scanning by the CIS is lower than the accuracy of scanning by the CCD.

Referring toFIG. 9, a process performed by image processing apparatus100according to the second embodiment will be described.FIG. 9is a flowchart showing the process performed by image processing apparatus100according to the second embodiment.

In step S901, CPU292controls transport roller202for example to transport an original.

In step S903, CPU292controls CIS scanning unit220, CCD280and movable stage260for example to cause CCD280to scan the front side of the original. CPU292also causes CIS scanning unit220to scan the rear side of the original.

In step S905, CPU292uses pattern matching between scan data562of the front side obtained by CCD280and screen pattern566bto calculate the rate of detection of the screen pattern on the front side. CPU292then determines whether the rate of detection of the screen pattern is equal to or higher than Level 1.

When the rate of detection of the screen pattern on the front side is not equal to or higher than Level 1 (NO in step S905), CPU292causes print unit150to cancel output of an image in step S907.

In the present embodiment, CPU292cancels output of an image regardless of the rate of detection of the screen pattern on the rear side. In this way, CPU292can surely prohibit copy of an original including a side whose copy is not permitted.

It should be noted that, in the case where the screen pattern for permitting copy is not embedded in one side of the original while the screen pattern for permitting copy is embedded in the other side, image processing apparatus100cannot copy the side where the screen pattern for permitting copy is embedded if the apparatus performs the process in the above-described manner. Accordingly, CPU292may prohibit only the output by print unit150of the side where the rate of detection of the screen pattern is low in step S907.

CPU292herein cancels the output of an image in step S907. CPU292, however, may cause print unit150to restrict the complete copy of an original, for example, to output an image where the characters “copy prohibited” overlap, instead of canceling output of an image.

When the rate of detection of the screen pattern on the front side is equal to or higher than Level 1 (YES in step S905), CPU292calculates in step S909the rate of detection of the screen pattern on the rear side through pattern matching between scan data562of the rear side obtained by CIS scanning unit220and screen pattern566b. CPU292then determines whether the rate of detection of the screen pattern is equal to or higher than Level 2.

When the rate of detection of the screen pattern on the rear side is equal to or higher than Level 2 (YES in step S909), the screen pattern is detected on both of the front side and the rear side. In other words, copy of both the front and rear sides of the original is permitted. CPU292accordingly causes print unit150to output an image in step S911.

When the rate of detection of the screen pattern on the rear side is not equal to or higher than Level 2 (NO in step S909), CPU292cannot determine whether the screen pattern is embedded in the rear side. CPU292accordingly performs a series of steps as described below to reverse the original and cause CCD280having a higher scanning accuracy to scan the rear side so as to determine whether or not the rear side includes the screen pattern based on the scan data562.

First, CPU292uses transport roller211, transport roller212and flap240to reverse the original and return the original back to the transport path in step S913.

Next, CPU292causes transport rollers203-210to transport the original in step S915.

In step S917, CPU292causes CCD280to scan the rear side of the original.

In step S919, CPU292calculates the rate of detection of the screen pattern in the image data through pattern matching between scan data562of the rear side obtained by CCD280and screen pattern566b. CPU292then determines whether the rate of detection of the screen pattern on the rear side is equal to or higher than Level 1.

When the rate of detection of the screen pattern on the rear side is equal to or higher than Level 1 (YES in step S919), CPU292causes print unit150to output an image in step S911.

When the rate of detection of the screen pattern on the rear side is not equal to or higher than Level 1 (NO in step S919), CPU292causes print unit150to cancel output of an image in step S907.

While an example has been described above where CPU292uses one determination level564to determine whether or not the rear side includes the screen pattern based on scan data562of the rear side that is obtained by CIS scanning, CPU292may use two determination levels564to determine whether or not the rear side includes the screen pattern, like the first embodiment.

Specifically, referring toFIG. 10, two determination levels564(Level 2 and Level 3) are set.FIG. 10is a diagram illustrating a modification of determination level564that is set in the second embodiment. The value of determination level564(Level 1) used by determination unit528for determining whether or not an original includes the screen pattern based on image data obtained by CCD scanning is similar to the above-described one.

Determination unit528uses determination levels564that are Level 2 and Level 3 when determination unit528determines from the result of CIS scanning whether or not the original includes the screen pattern. When the rate of detection of the screen pattern is equal to or lower than Level 2, determination unit528determines that the original does not include the screen pattern. Here, Level 2 is a value representing a lower rate of detection than Level 1. Further, determination unit528determines that the original includes the screen pattern when the rate of detection is equal to or higher than Level 3. Here, Level 3 is a value representing a higher rate of detection than Level 1.

When the rate of detection is between Level 2 and Level 3, determination unit528determines that whether or not the original includes the screen pattern cannot be identified. Since the CIS scanning accuracy is lower than the CCD scanning accuracy, the value Level 2 of the determination level used for determining that the original surely does not include the screen pattern is set lower than Level 1, and the value Level 3 of the determination level used for determining that the original surely includes the screen pattern is set higher than Level 1.

A process performed by image processing apparatus100in the case where determination levels564as described above are used will be described with reference toFIG. 11.FIG. 11is a flowchart showing the process performed by image processing apparatus100according to the modification of the second embodiment.

In step S1101, CPU292controls transport roller202for example to transport an original.

In step S1103, CPU292controls CIS scanning unit220, CCD280and movable stage260for example to cause CCD280to scan the front side of the original. CPU292also causes CIS scanning unit220to scan the rear side.

In step S1105, CPU292calculates the rate of detection of the screen pattern on the front side through pattern matching between scan data562of the front side obtained by CCD280and screen pattern566b. CPU292then determines whether the rate of detection of the screen pattern is equal to or higher than Level 1.

When the rate of detection of the screen pattern on the front side is not equal to or higher than Level 1 (NO in step S1105), CPU292causes print unit150to cancel output of an image in step S1107.

When the rate of detection of the screen pattern on the front side is equal to or higher than Level 1 (YES in step S1105), CPU292calculates in step S1109the rate of detection of the screen pattern on the rear side through pattern matching between scan data562of the rear side obtained by CIS scanning unit220and screen pattern566b. CPU292then determines whether the rate of detection of the screen pattern is higher than Level 2.

When the rate of detection of the screen pattern on the rear side is not higher than Level 2 (NO in step S1109), CPU292causes print unit150to cancel output of an image in step S1107.

When the rate of detection of the screen pattern on the rear side is higher than Level 2 (YES in step S1109), CPU292determines in step S1111whether the rate of detection of the screen pattern on the rear side is equal to or higher than Level 3.

When the rate of detection of the screen pattern on the rear side is equal to or higher than Level 3 (YES in step S1111), the screen pattern is detected on both of the front side and the rear side. Namely, copy of both the front and rear sides of the original is permitted. In this case, CPU292causes print unit150to output an image in step S1113.

When the rate of detection of the screen pattern on the rear side is not equal to or higher than Level 3 (NO in step S1111), CPU292cannot determine whether or not the screen pattern is embedded in the rear side. CPU292accordingly performs a series of steps as described below to reverse the original and cause CCD280with a higher scanning accuracy to scan the rear side so as to determine, from the scan data, whether or not the rear side includes the screen pattern.

First, CPU292uses transport roller211, transport roller212and flap240to reverse the original and return the original back to the transport path in step S1115.

Then, CPU292causes transport rollers203-210to transport the original in step S1117.

In step S1119, CPU292causes CCD280to scan the rear side of the original.

In step S1121, CPU292calculates the rate of detection of the screen pattern in the image data through pattern matching between scan data562of the rear side that is obtained by CCD280and screen pattern566b. CPU292then determines whether the rate of detection of the screen pattern on the rear side is equal to or higher than Level 1.

When the rate of detection of the screen pattern on the rear side is equal to or higher than Level 1 (YES in step S1121), CPU292causes print unit150to output an image in step S1113.

When the rate of detection of the screen pattern on the rear side is not equal to or higher than Level 1 (NO in step S1121), CPU292causes print unit150to cancel output of an image in step S1107.

According to the present modification, image processing apparatus100may not perform the process steps such as reversal and re-scanning of an original for which it is determined in step S1109that the original does not surely include the screen pattern. In this way, the modification can reduce the number of process steps.

Third Embodiment

In connection with a third embodiment, image processing apparatus100will be described having the security screen pattern capability using a plurality of different types of screen patterns.

In general, the easiness of detection of a screen pattern embedded in an original varies depending on the type of the screen pattern. Accordingly, the type of the screen pattern is changed according to the type of information to be embedded. For example, in an original, important information such as the information that copy is permitted/prohibited and password may be embedded as an easy-to-detect screen pattern, and other information may be embedded as a difficult-to-detect screen pattern.

When such an original is scanned, the easy-to-detect screen pattern is detected while the difficult-to-detect screen pattern may not be detected in some cases. In the case where a screen pattern that is easier to detect, for example, an important screen pattern such as the one indicating that copy is permitted/prohibited is detected, it may become unnecessary at this time to know the information of the difficult-to-detect screen pattern, depending on the information of the easy-to-detect screen pattern. Image processing apparatus100according to the present embodiment uses the difference in easiness to detect according to the type of screen pattern to reduce the number of times an original is scanned. In the following description, the difference in easiness to detect according to the type of the screen pattern corresponds to the easiness to make a determination in pattern matching described hereinlater, namely the easiness to recognize a pattern. The factor of the difference in easiness to detect, however, is not limited to the above-described one.

The hardware configuration and the functional configuration of image processing apparatus100according to the third embodiment are substantially identical to those of the first and second embodiments. Therefore, the description thereof will not be repeated. It should be noted that the process performed by determination unit528differs from those of the first and second embodiments as described below.

Image processing apparatus100according to the present embodiment also uses determination level564for determining whether or not an original includes a screen pattern, like other embodiments. This determination level564will be described with reference toFIG. 12.FIG. 12is a diagram illustrating determination level564set in the third embodiment.

In the present embodiment, a screen pattern included in an original includes a first screen pattern that is relatively easy to detect and a second screen pattern that is relatively difficult to detect.

When the rate of detection of the first screen pattern in scan data obtained by scanning with the CCD is equal to or higher than Level 1, determination unit528determines that the original includes the first screen pattern and, when the rate of detection of the first screen pattern is not equal to or higher than Level 1, determination unit528determines that the original does not include the first screen pattern.

When the rate of detection of the second screen pattern in the scan data obtained by scanning with the CCD is equal to or higher than Level 2, determination unit528determines that the original includes the second screen pattern. When the rate of detection of the second screen pattern is not equal to or higher than Level 2, determination unit528determines that the original does not include the second screen pattern.

Here, Level 2 is set higher than Level 1, in order to avoid the possibility that an erroneous determination is made as to the second screen pattern that is more difficult to detect than the first screen pattern. It should be noted that the relative magnitudes of Level 1 and Level 2, however, are not limited to the above-described ones, and are set appropriately according to the nature of the screen pattern.

When the rate of detection of the first screen pattern in the scan data obtained by scanning with the CIS is equal to or higher than Level 3, determination unit528determines that the original includes the first screen pattern. When the rate of detection of the first screen pattern is not equal to or higher than Level 3, determination unit528determines that the original does not include the first screen pattern.

Further, when the rate of detection of the second screen pattern in the scan data obtained by scanning with the CIS is equal to or higher than Level 4, determination unit528determines that the original includes the second screen pattern. When the rate of detection of the second screen pattern is not equal to or higher than Level 4, determination unit528determines that whether or not the original includes the second screen pattern cannot be identified.

Here, for a similar reason to the reason why Level 2 is set higher than Level 1, Level 4 is set higher than Level 3. It should be noted that the relative magnitudes of Level 3 and Level 4 are not limited to the above-described ones, and are appropriately set according to the nature of the screen pattern.

Further, as described in connection with the first embodiment and the second embodiment, since the scanning accuracy of the CIS system is lower than the scanning accuracy of the CCD system, Level 3 and Level 4 are set higher than Level 1 and Level 2 respectively.

Referring toFIG. 13, a process performed by image processing apparatus100according to the third embodiment will be described.

Here, a first screen pattern represents the information that copy is permitted, and a second screen pattern represents the information concerning print such as printed date and time and the name of the apparatus used for printing. When the first screen pattern and the second screen pattern are detected, copy of the original is permitted.

In step S1301, CPU292controls transport roller202for example to transport an original.

In step S1303, CPU292controls CIS scanning unit220, CCD280and movable stage260for example to scan both sides of the original. CPU292causes CCD280to scan the front side of the original and causes CIS scanning unit220to scan the rear side of the original.

In step S1305, CPU292calculates the rate of detection of the first screen pattern on the front side through pattern matching between image data of the front side obtained by CCD280and the screen pattern. CPU292then determines whether the rate of detection of the first screen pattern is equal to or higher than Level 1.

When the rate of detection of the first screen pattern on the front side is not equal to or higher than Level 1 (NO in step S1305), copy of the front side is not permitted. Therefore, CPU292causes print unit150to cancel output of an image in step S1307.

When the rate of detection of the first screen pattern on the front side is equal to or higher than Level 1 (YES in step S1305), CPU292determines whether the rate of detection of the second screen pattern on the front side is equal to or higher than Level 2 in step S1309.

When the rate of detection of the second screen pattern on the front side is not equal to or higher than Level 2 (NO in step S1309), CPU292causes print unit150to cancel output of an image in step S1307.

In the present embodiment, CPU292causes the output to be cancelled regardless of the rate of detection of the screen pattern on the rear side, if the first screen pattern or the second screen pattern is not detected on the front side. In this way, CPU292can surely prohibit copy of an original that includes a side whose copy is not permitted.

This process, however, causes the state where image processing apparatus100does not copy the rear side even if copy of the rear side is permitted. Accordingly, CPU292may cause print unit150to cancel only the output of a side whose copy is not permitted in step S1307.

Here, CPU292causes the output of an image to be cancelled in step S1307. CPU292, however, may causes print unit150to perform another operation for restricting complete copy of an original, for example, to output the characters “copy prohibited” overlapping the image, instead of canceling the output of the image.

When the rate of detection of the second screen pattern on the front side is equal to or higher than Level 2 (YES in step S1309), CPU292calculates in step S1311the rate of detection of the first screen pattern on the rear side through pattern matching between image data of the rear side obtained by CIS scanning unit220and the screen pattern. CPU292then determines whether the rate of detection of the first screen pattern is equal to or higher than Level 3.

When the rate of detection of the first screen pattern on the rear side is not equal to or higher than Level 3 (NO in step S1311), copy of the rear side is not permitted. Therefore, CPU292causes print unit150to cancel output of an image in step S1307.

When the rate of detection of the first screen pattern on the rear side is equal to or higher than Level 3 (YES in step S1311), CPU292calculates in step S1313the rate of detection of the second screen pattern on the rear side through pattern matching between image data of the rear side obtained by CIS scanning unit220and the screen pattern. CPU292then determines whether the rate of detection of the second screen pattern is equal to or higher than Level 4.

When the rate of detection of the second screen pattern on the rear side is equal to or higher than Level 4 (YES in step S1313), copy of both of the front side and the rear side is permitted. Accordingly, CPU292causes print unit150to output an image in step S1315.

When the rate of detection of the second screen pattern on the rear side is not equal to or higher than Level 4 (NO in step S1313), CPU292cannot determine whether or not the second screen pattern is embedded in the rear side. Accordingly, CPU292performs a series of process steps as described below to reverse the original, cause CCD280with a higher scanning accuracy to scan the rear side, and determine whether or not the rear side includes the screen pattern based on the scan data.

First, CPU292uses transport roller211, transport roller212and flap240to reverse the original and return the original back to the transport path in step S1315.

Then, CPU292causes transport rollers203-210to transport the original in step S1317.

In step S1319, CPU292causes CCD280to scan the rear side of the original.

In step S1321, CPU292calculates the rate of detection of the second screen pattern in the image data through pattern matching between the image data of the rear side obtained by CCD280and the screen pattern. CPU292then determines whether the rate of detection of the second screen pattern on the rear side is equal to or higher than Level 2.

When the rate of detection of the second screen pattern on the rear side is equal to or higher than Level 2 (YES in step S1321), CPU292causes print unit150to output an image in step S1315.

When the rate of detection of the second screen pattern on the rear side is not equal to or higher than Level 2 (NO in step S1321), CPU292causes print unit150to cancel output of an image in step S1307.

Image processing apparatus100according to the present embodiment determines whether or not each of screen patterns that are different in type from each other is included in an original, according to the degree of easiness or the degree of difficulty in detecting the screen pattern depending on the type of the screen pattern. This image processing apparatus100can thus reduce the number of process steps necessary for detecting the screen pattern.

An example has been described above where one determination level (Level 4)564is used by CPU292for determining whether or not the rear side includes the second screen pattern based on image data of the rear side obtained by scanning with the CIS system. CPU292, however, may use two determination levels564to make the determination, like other embodiments described above.

Further, image processing apparatus100in the present embodiment has been described as the one permitting copy of an original when the first screen pattern and the second screen pattern are detected. The relation between the result of detection of a predetermined pattern and subsequent process steps is not limited to this. For example, if the first screen pattern represents information that copy is prohibited, image processing apparatus100may prohibit copy of an original when the first screen pattern is detected. Where this is described in connection withFIG. 13, the determinations YES and NO of steps S1305and S1311are replaced with each other.