JP5219909B2 - Image forming apparatus, print control program, and recording medium - Google Patents

Description

  The present invention relates to an image forming apparatus capable of performing a predetermined printing process on a sheet such as paper.

  In some cases, it is necessary to perform a desired process on a sheet such as a printed matter or a distribution document on which image information is recorded by means of an image forming apparatus such as a printer, a copier, or a multifunction machine.

  For example, it may be necessary for a sheet on which highly confidential image information is recorded to prevent others from understanding the image information from the viewpoint of maintaining confidentiality.

  Specifically, a sheet having highly confidential image information is often disposed of by cutting it with a shredder, breaking it manually, or incinerating it.

  There are few image forming apparatuses such as conventional printers and copiers equipped with a shredder, and even if a shredder is attached, such an image forming apparatus must be provided with a separate shredder. Increase in size and cost.

  Further, since the shredder is relatively noisy, there are many cases where the shredder is located away from the shredder, which is not convenient when performing the cutting work by the shredder. In order to avoid this, the sheet on which image information that should be kept confidential is manually broken or manually cut by a manual cutter such as a scissor equipped with a shredder function and then discarded. Therefore, the work efficiency deteriorates.

  In this regard, in the conventional image forming apparatus, a desired printing process is not performed on a sheet on which image information is recorded, and a desired print process is not performed on a sheet on which image information is not recorded. It is merely configured to perform the printing process.

  For example, the image forming apparatus described in Patent Document 1 below is configured to recognize image data to be printed prior to printing on a sheet on which image information is not recorded, and to perform image processing based on the image data. For the original image data, when it is determined that the solid black area exists at the edge position of the original image and the boundary of the solid black area is linear, the solid black area having a linear boundary is determined. It is merely configured to perform image processing for converting black pixels into white pixels.

JP 2007-150849 A

  Accordingly, the present invention provides a desired print process (for example, a print process in which the image information cannot be understood by others) on the image information of a sheet on which image information (for example, highly confidential image information) is recorded. It is an object of the present invention to provide an image forming apparatus, a print control program, and a recording medium.

The present invention, in order to solve the above problems, a sheet feeding unit for supplying sheets, a sheet conveying path which the sheet is conveyed to be fed from the sheet feeding unit, the conveyed sheet conveying path sheet An image forming apparatus comprising an image forming unit for printing and a control unit for controlling a printing operation, wherein the image sensor reads an image of a sheet conveyed along the sheet conveying path, and performs printing on one side. The sheet is reversed so that the front and back sides of the sheet are reversed by the sheet reversing path, and then the other side is printed, and the sheet conveying path includes the sheet feeding unit and the image forming unit. And a second sheet conveyance path that forms a part of the sheet reversing path, and the image sensor is located in the sheet reversing path. That the is provided in the second sheet conveying path, the control unit, the said second said sheet is conveyed to the sheet conveying path in once the sheet inverter path a sheet supplied from the sheet supply portion a read by the image sensor in the second sheet transport path, said second and based on the reading result by the image sensor of the sheet conveyed through the sheet conveying path, if it is determined that there is an image on the sheet, the first An image configured to convey the sheet in the two-sheet conveyance path to the first sheet conveyance path and perform concealment printing for concealing the image on the sheet by the image forming unit. A forming apparatus is provided.

According to the image forming apparatus of the present invention, the control unit performs the concealment printing for concealing the image of the sheet on the sheet read by the image sensor of the sheet conveyed on the sheet conveyance path. The sheet on which highly confidential image information is recorded can be subjected to a printing process in which the image information cannot be understood by others. In addition, since the image is concealed without providing a separate shredder, confidentiality can be realized without increasing the size of the apparatus and keeping the cost low. Further, since the image forming function of the image forming apparatus is used, confidentiality can be maintained without performing a cutting operation by a shredder or a manual cutting machine, and hence without deteriorating convenience and workability. It becomes possible.

Then , by using the sheet reversing path as the sheet conveying path, a desired printing process is performed on the image information of the sheet on which the image information is recorded without further increasing the size of the apparatus. Can do.
In the image forming apparatus according to the present invention, when the control unit determines that there is no image on both sides of the sheet based on a reading result of the sheet conveyed by the image sensor on the second sheet conveyance path. A mode in which the sheet is discharged to the outside without passing through the forming portion can be exemplified.
According to this specific matter, when there is no image on both sides of the sheet, it is possible to omit useless printing operations by discharging the sheet to the outside without passing through the image forming unit. This configuration is particularly effective when an unprinted sheet is mixed with the sheet supplied from the sheet supply unit.
In the image forming apparatus according to the aspect of the invention, when the control unit determines that there are images on both sides of the sheet based on a reading result of the sheet conveyed by the image sensor on the second sheet conveyance path. The sheet is conveyed to the first sheet conveyance path, and concealing printing is performed on the one side of the sheet by the image forming unit to conceal the image on the one side. A mode in which the front and back sides are reversed so that the other side of the sheet is concealed by the image forming unit to conceal the image on the other side can be exemplified.
In this specific matter, since the concealment printing for concealing the images on both sides of the sheet is performed on the sheet read by the image sensor, for example, on the sheet on which the highly confidential image information is recorded on both sides It is possible to perform a printing process in which the image information cannot be understood by others. Moreover, since the images on both sides are concealed without providing a separate shredder, confidentiality can be realized without increasing the size of the apparatus and keeping the cost low. Further, since the image forming function of the image forming apparatus is used, confidentiality can be maintained without performing a cutting operation by a shredder or a manual cutting machine, and hence without deteriorating convenience and workability. it can.
In the image forming apparatus according to the present invention, when the control unit determines that there is an image on one side of the sheet based on a reading result by the image sensor of the sheet conveyed through the second sheet conveyance path, A mode in which the sheet is transported to the first sheet transport path and concealed printing for concealing the image on the one surface of the one surface of the sheet by the image forming unit can be exemplified.
In the image forming apparatus according to the present invention, the control unit has no image on one side of the sheet based on a reading result of the sheet conveyed by the image sensor on the second sheet conveyance path, and the other side. When the sheet is determined to have an image, the sheet is conveyed to the first sheet conveyance path, and after passing through the image forming unit without performing concealment printing on the one surface, the sheet is A mode in which concealment printing is performed by reversing the sheet so that the front and back sides are reversed by the sheet reversal path, and concealing the image on the other side by the image forming unit on the other side of the sheet.

In the image forming apparatus according to the aspect of the invention, it is preferable that the image sensor is two image sensors respectively disposed on both sides with the sheet conveyance path constituting the sheet reversing path therebetween.

  In this specific matter, since the two image sensors are arranged on both sides with the sheet conveyance path in between so as to read both sides of the sheet, both sides of the sheet can be read by one sheet supply. Can do.

In the image forming apparatus according to the present invention, the sheet supply unit has a manual sheet supply port, and the sheet conveyed through the sheet reversing path can be discharged to the outside from the manual sheet supply port. The controller is configured to manually feed a sheet to be ejected based on a reading result by the image sensor or a sheet to be ejected after a printing operation based on a reading result by the image sensor from the sheet reversing path. It is preferable to discharge to the sheet supply port.

  In this specific matter, since the sheet to be discharged is discharged from the sheet reversing path to the manual sheet supply port, it is possible to avoid confusion with a sheet discharged by a normal printing operation, and the convenience is increased accordingly. Can be improved.

In the image forming apparatus according to the present invention, the image forming apparatus includes a sheet discharge unit having a sheet discharge port for discharging the sheet to the outside, and the control unit discharges the sheet to be discharged to the sheet discharge port or the sheet For example, it is possible to selectively switch whether the sheet is discharged from the reverse path to the manual sheet supply port.

  In this specific matter, the sheet to be discharged can be discharged to the manual sheet supply port as necessary.

The image forming apparatus according to the present invention includes a display panel that displays an image of a sheet read by the image sensor, and the control unit temporarily displays the image of the sheet read by the image sensor so that the image can be partially selected. An example of performing the concealment printing so that an image corresponding to the selected portion is concealed on the sheet after a portion to be concealed is selected by manual operation and displayed on the panel.

  In this specific matter, an image read from a sheet is once displayed on the display panel, and a portion to be concealed is selected by the manual operation, so that an image of a portion of the sheet that should not be concealed is arbitrarily concealed. It becomes possible to choose and leave.

The image forming apparatus according to the present invention, the control unit may have lines the concealed printing for a part of the image of a sheet read by the image sensor and the image newly separate the was concealed by the concealing print It is preferable to print on a sheet.

  In this specific matter, since the concealed image is newly printed on another sheet, an image in which a portion to be concealed with respect to the sheet read by the image sensor is concealed and an image that is not concealed are recorded. Thus, it is possible to record only the image of the portion to be concealed with respect to the other sheet.

  In the case where the image forming apparatus prints a plurality of types of colors as in the case of a color image forming apparatus, the color of the concealment printing is a color darker than a predetermined density (especially from the viewpoint of improving the concealment property). Black) is preferred.

  In the image forming apparatus according to the present invention, the image forming apparatus includes a display panel that displays an image of the sheet read by the image sensor, and the control unit temporarily displays the image of the sheet read by the image sensor on the display panel, A mode in which additional information including at least one of characters and graphics is inserted into the image displayed on the display panel can be exemplified.

  In this specific matter, in addition to the already recorded image information, the additional information including at least one of characters and figures can be inserted into the sheet read by the image sensor.

  The image forming apparatus according to the present invention includes a computer having a display panel, and the display panel in the computer is provided above the image forming unit, and the control unit is a control unit constituting the computer. An aspect can be illustrated.

  In this specific matter, since the display panel in the computer is provided above the image forming unit, the image of the sheet read by the image sensor is displayed on a relatively large screen of the display panel in an easy-to-view state. be able to. Moreover, since the control unit is a control unit that constitutes the computer, the control unit can control the printing operation of the image forming apparatus. For example, for the image displayed on the screen of the display panel, Various image editing such as processing can be performed using the print control program.

In the present invention, it is preferable that the computer temporarily conveys the sheet supplied from the sheet supply unit to the second sheet conveyance path in the sheet reversing path, and the sheet is conveyed by the image sensor in the second sheet conveyance path. reading, said based on the image sensor according to the reading result of the sheet conveyed through the second sheet transport path, when it is determined that there is an image on the sheet, wherein the sheet in the second sheet transport path According to the present invention, a printing control program that causes a sheet to be conveyed to a first sheet conveyance path and to function as a unit including a concealment printing unit that performs concealment printing for concealing the image on the sheet by the image forming unit. Also provided is a computer-readable recording medium characterized by recording such a print control program. To.

  As described above, according to the present invention, desired print processing (for example, the image information is understood by other people) for the image information of the sheet on which the image information (for example, highly confidential image information) is recorded. It is possible to provide an image forming apparatus capable of performing a printing process that cannot be performed.

1 is a cross-sectional view schematically showing an overall configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram schematically showing a configuration of a control system of the image forming apparatus shown in FIG. 1. FIG. 2 is a view of the image forming apparatus shown in FIG. 1 as viewed from the side of a manual sheet supply port. FIG. 4A is a diagram showing a setting screen of a display panel that is switched by a screen switching key in the operation panel unit, where FIG. 1A is a diagram showing a discharge port setting screen, and FIG. 2B is a hidden printing setting screen. FIG. 8C is a diagram illustrating a hidden print type setting screen. FIG. 2A is a diagram illustrating an example of operation of concealment printing by the image forming apparatus illustrated in FIG. 1, in which FIG. 1A illustrates a state in which a sheet is read by the first and second image sensors. ) Is a diagram showing a state in which the rear end of the sheet has passed through the second image sensor, and FIG. (C) is a diagram showing a state in which the sheet is concealed and printed. FIG. 11 is a diagram for explaining the entire concealment printing for the entire image of a sheet on which image information is recorded, and FIG. (A) is a diagram illustrating a state in which the concealment printing is not performed on the sheet; (B) is a diagram showing a state where solid printing is performed as concealment printing for the sheet, and FIG. (C) is a diagram showing a state where halftone printing is performed as concealment printing for the sheet. is there. FIG. 5 is a diagram showing a display screen of a display panel on which an image read from a sheet is displayed and various keys arranged around the display screen, and FIG. (A) is a diagram showing a screen on which an image read from the sheet is displayed. FIG. 4B is a diagram illustrating a screen in which an image read from a sheet is partially selected. FIG. 2 is a schematic cross-sectional view illustrating another example of the image forming apparatus illustrated in FIG. 1, in which FIG. 1A illustrates a state in which a display panel of the image forming apparatus is closed, and FIG. 2 is a diagram illustrating a state in which a display panel of the image forming apparatus is opened. FIG. FIG. 9A is a schematic side view showing the display panel of the image forming apparatus shown in FIG. 8, and FIG. 9A is a view showing a state in which an image read from the sheet is displayed on the display panel, and FIG. FIG. 9 is a diagram showing a state in which a portion to be hidden is selected for an image displayed on the display panel, and FIG. (C) is a diagram showing additional information inserted into the image displayed on the display panel. It is a figure which shows the state currently performed.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such embodiments. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. It is understood.

(Overall configuration of image forming apparatus)
FIG. 1 is a cross-sectional view schematically showing an overall configuration of an image forming apparatus 100 according to an embodiment of the present invention. FIG. 2 is a block diagram schematically showing the configuration of the control system of the image forming apparatus 100 shown in FIG.

  An image forming apparatus 100 illustrated in FIG. 1 includes a sheet supply unit 10 that supplies a sheet P such as paper, a sheet conveyance path 20 that conveys a sheet P that is supplied from the sheet supply unit 10, The image forming unit 30 that prints the sheet P, the control unit 40 that controls the printing operation (not shown in FIG. 1, refer to FIG. 2), and the sheet discharge unit 50 that discharges the sheet P to the outside. . Here, the sheet conveyance path 20 refers to a conveyance path of the sheet P that is conveyed between the sheet supply unit 10 and the image forming unit 30. In the present embodiment, the sheet conveyance path 20 includes a first sheet conveyance path 21 and a second sheet conveyance path 22. The first sheet conveyance path 21 is a path between the sheet supply unit 10 and the image forming unit 30, and guides the sheet P from the sheet supply unit 10 to the image forming unit 30. The second sheet conveying path 22 constitutes a part of a sheet reversing path 61 described later, and is a path between the sheet reversing roller unit 62 and the sheet supply unit 10 in the sheet reversing path 61.

  Here, the sheet supply unit 10 includes a sheet supply cassette unit 11 and a manual sheet supply unit 12.

  The sheet supply cassette unit 11 supplies a large number of stored sheets P one by one to the sheet conveyance path 20. Specifically, the sheet supply cassette unit 11 includes a sheet supply cassette 11a that can store a large number of sheets P, and a sheet supply roller unit 11b that supplies the sheets P stored in the sheet supply cassette 11a one by one to the sheet conveyance path 20. And.

  The sheet supply cassette 11a is disposed below the image forming unit 30, and can be pulled out to accommodate the sheet P. The sheet supply roller unit 11 b is configured to pull out the uppermost sheet P stored in the sheet supply cassette 11 a and send it out to the sheet conveyance path 20.

  The manual sheet supply unit 12 has a manual sheet supply port 12a, and supplies one or many sheets P one by one from the sheet supply port 12a to the sheet conveyance path 20. The manual sheet supply unit 12 further includes a manual tray 12b on which the sheet P is placed and a manual roller unit 12c that supplies the sheets P placed on the manual tray 12b one by one to the sheet conveyance path 20. (See the chain line in FIG. 1).

  The first sheet conveyance path 21 guides the sheet P sent from the sheet supply cassette unit 11 or the manual sheet supply unit 12 to the image forming unit 30.

  In the present embodiment, the image forming unit 30 performs printing by an electrophotographic image forming process. The image forming unit 30 includes a pre-registration conveyance path 31, a registration roller unit 32, an image forming engine unit 33, and a fixing unit 34.

  The pre-registration conveyance path 31 guides the sheet P sent from the sheet conveyance path 20 to the registration roller unit 32.

  The registration roller unit 32 conveys the sheet P in synchronization with the image forming position of the sheet P with respect to the image formed by the image forming engine unit 33. Here, the registration roller unit 32 includes a paper top roller (PS roller) 32 a that is driven to rotate at a timing synchronized with the image forming position of the sheet P with respect to the image formed by the image forming engine unit 33. .

  The image forming engine unit 33 includes an electrostatic latent image carrier (here, a photosensitive drum) 33a, a developing device 33b, a charging device (here, a charging brush) 33c, and an exposure device (here, an image writing LED array) 33d. And a transfer device (here, transfer roller) 33e, a cleaning device (not shown), and a charge eliminating device (not shown).

  In the image forming engine unit 33, the surface of the photosensitive drum 33a is uniformly charged by the charging brush 33c when an image is formed (printed). An electrostatic latent image is formed by irradiating the charge charged on the surface of the photosensitive drum 33a by the charging brush 33c with image light from the image writing LED array 33d based on image data transmitted from an external device. . A developer containing toner is supplied to the obtained electrostatic latent image by the developing device 33b to form a visible image (toner image). Further, the obtained visible image is transferred by the transfer roller 33e to the sheet P conveyed in synchronization with the PS roller 32a. Further, the transfer residual toner remaining on the surface of the photosensitive drum 33a without being transferred by the transfer roller 33e is removed by the cleaning device. Further, the residual charge remaining on the surface of the photosensitive drum 33a is neutralized by the neutralizing device.

  The fixing unit 34 receives the sheet P on which the visible image is transferred and fixes the visible image on the sheet P, and includes a heat roller 34a and a pressure roller 34b. The heat roller 34a and the pressure roller 34b are pressed against each other by a pressing means (not shown), and the sheet P is conveyed while being sandwiched between the rollers 34a and 34b. The temperature of the heat roller 34a is controlled so as to reach a predetermined fixing temperature, and the toner image transferred to the sheet P is melted, mixed, and pressed by thermally pressing the sheet P together with the pressure roller 34b. On the other hand, it has a function of heat fixing.

  Each component that performs these series of printing operations is driven by a main motor 35 provided above the first sheet conveying path 21.

  The sheet discharge unit 50 includes a sheet discharge port 51, and includes a sheet discharge path 52 that communicates with the sheet discharge port 51, a sheet discharge roller unit 53, and a discharge tray 54 that discharges the sheet P. Here, the sheet discharge unit 50 is provided at an end portion on the opposite side to the sheet supply side in the sheet conveyance direction (the direction of arrow A in FIG. 1).

  The sheet discharge path 52 guides the sheet P sent from the image forming unit 30 to the sheet discharge port 51. Here, the sheet discharge path 52 is curved so that the sheet P conveyed in the substantially horizontal direction from the image forming unit 30 is inverted approximately 180 ° upward.

  The sheet discharge roller unit 53 discharges the sheet P sent from the image forming unit 30 to the sheet discharge path 52 to the outside from the sheet discharge port 51. Specifically, the sheet discharge roller unit 53 is driven by the discharge drive unit 71 (see FIG. 2) via the drive transmission means 71a, so that the sheet P is conveyed in the sheet conveyance direction A. Here, the sheet discharge roller portion 53 includes a discharge guide roller 53 a provided in the vicinity of a branch portion (here, a curved portion top portion) 52 a of the sheet discharge path 52 and the sheet reversing path 61, and the vicinity of the sheet discharge port 51. And a paper discharge roller 53b.

  The discharge tray 54 is a tray on which the sheet P discharged from the sheet discharge port 51 is placed. Here, the discharge tray 54 is provided on the upper surface of the image forming unit 30, and the sheet P discharged from the sheet discharge port 51 is placed face down.

  In the present exemplary embodiment, the sheet discharge roller unit 53 conveys the sheet P in the sheet conveyance direction A, and in addition to the sheet P in the sheet conveyance direction A, the sheet reverse conveyance direction (arrow B in FIG. 1). Direction).

  Then, as the double-sided printing function, the image forming apparatus 100 reverses the sheet P printed on one side by the image forming unit 30 so that the front and back sides are reversed, and then performs printing on the other side. In addition, a sheet reversing conveyance unit 60 that leads to the image forming unit 30 is provided.

  The sheet reversing and conveying unit 60 includes a sheet reversing path 61 for double-sided printing, a sheet reversing roller unit 62, and a sheet handle unit 63.

  The sheet reversing path 61 reverses the sheet P conveyed in the sheet reverse conveying direction B from the branching part 52a of the sheet discharge path 52 so that the front and back are reversed, and then guides the sheet P toward the sheet handle part 63. It has become. Here, the sheet reversing path 61 extends downward from the branch portion 52a of the sheet discharge path 52, and is curved so as to change direction by approximately 90 ° toward the sheet handle portion 63 side.

  The sheet reversing roller unit 62 is configured to convey the sheet P conveyed in the sheet reverse conveying direction B from the branch portion 52a of the sheet discharge path 52 toward the sheet handle unit 63 side. Specifically, the sheet reversing roller unit 62 is driven by the reversal driving unit 72 (see FIG. 2) via the drive transmission means 72a, so that the sheet P is conveyed in the sheet reverse conveying direction B. Here, the sheet reversing roller unit 62 includes a first sheet reversing guide roller 62a provided in the vicinity of the end of the second sheet conveying path 22 opposite to the sheet feeding unit 10 side, and a first sheet reversing guide roller. 62 a and a second sheet reversing guide roller 62 b provided between the branch portion 52 a of the sheet discharge path 52.

  The sheet handle unit 63 is a print handle operation for delivering the sheet P conveyed in the sheet conveyance direction A from the sheet supply cassette unit 11 or the manual sheet supply unit 12 to the image forming unit 30, and the sheet. A reversing handle operation is performed to deliver the sheet P conveyed in the sheet reversing direction B in the sheet reversing direction B by the reversing roller unit 62 so as to be reversed by approximately 180 ° to the image forming unit 30. Specifically, the seat handle portion 63 is driven by the handle drive portion 73 (see FIG. 2) via the drive transmission means 73a so as to rotate in a predetermined forward rotation direction (the direction of arrow C in FIG. 1). It has become. Here, the sheet handle portion 63 includes a sheet handle intermediate roller 63a. The sheet handle intermediate roller 63a rotates in the forward rotation direction C while holding the sheet P conveyed through the first sheet conveyance path 21 or the second sheet conveyance path 22 during the printing handle operation or the reversing handle operation. Then, the downstream end (front end) of the sheet P in the sheet conveyance direction A is delivered to the pre-registration conveyance path 31.

  When the image forming apparatus 100 according to the present embodiment constitutes a copying machine, an image reading apparatus 300 (see a chain line in FIG. 1) such as a scanner unit that reads an image of a document is provided.

  In the image forming apparatus 100 described above, when printing on one side of the sheet P (single-sided printing), first, the sheet P supplied from the sheet supply cassette unit 11 or the manual sheet supply unit 12 is the first sheet. The sheet is conveyed from the conveyance path 21 to the registration roller section 32 via the pre-registration conveyance path 31 by the printing handle operation of the sheet handle section 63. Next, the sheet P conveyed to the registration roller unit 32 is conveyed by the registration roller unit 32 to the transfer site in synchronization with the toner image on the photosensitive drum 33a. A toner image on the photosensitive drum 33a is transferred onto the sheet P conveyed to the transfer portion by a transfer electric field applied to the transfer roller 33e, and the toner image is fixed on the sheet P by the fixing unit 34. . At this time, the sheet discharge roller unit 53 is in a state of transporting the sheet P in the sheet transport direction A. In this state, the sheet P on which the toner image is fixed is discharged from the sheet discharge path 52 to the discharge tray 54 via the sheet discharge port 51 by the sheet discharge roller unit 53.

  On the other hand, when printing on both sides of the sheet P (double-sided printing), as described above, the sheet P that has finished single-sided printing and has passed through the fixing unit 34 is upstream of the sheet conveying direction A by the sheet discharge roller unit 53. The side end (rear end) is conveyed to a position where it passes through the branching portion 52a of the sheet discharge path 52 with the sheet reversing path 61. At this time, the rear end side of the sheet P faces in a substantially vertical direction. Thereafter, when the sheet discharge roller unit 53 rotates in the reverse direction while being held by the sheet discharge roller unit 53, the sheet P held by the sheet discharge roller unit 53 is directed toward the sheet reverse roller unit 62 in the reverse sheet conveyance direction B. Transport to. Then, after the sheet P transported in the sheet reverse transport direction B by the sheet reverse roller section 62 is transported to the registration roller section 32 through the pre-registration transport path 31 by the reverse handle operation of the sheet handle section 63, As described above, the printing operation is performed on the other side of the sheet P from the image forming unit 30. The printed sheet P is discharged from the sheet discharge path 52 to the discharge tray 54 through the sheet discharge port 51 by the sheet discharge roller unit 53. Thus, duplex printing is completed.

  Note that the image forming apparatus 100 may further include a reverse switching member provided in the vicinity of the branch portion 52a between the sheet discharge path 52 and the sheet reverse path 61. The reversal switching member includes a discharge operation for guiding the sheet P sent from the image forming unit 30 in the sheet conveyance direction A toward the sheet discharge port 51 when the sheet P is discharged from the sheet discharge port 51, and the sheet P. Can be switched between the reversing operation for guiding the sheet P sent in the sheet reverse conveyance direction B from the sheet discharge path 52 to the sheet reversing path 61.

(Description of features of the present invention)
In the image forming apparatus 100 according to the present embodiment, an image sensor 90 is disposed in the sheet conveyance path 20 (here, the second sheet conveyance path 22).

  In the present embodiment, the sheet reversing path 61 communicates with a middle portion of the first sheet conveying path 21. A part of the sheet reversing path 61 (here, a path on the way from the communicating portion 21a of the first sheet conveying path 21 to the branching section 52a of the sheet discharging path 52) is the second sheet conveying path 22. An image sensor 90 is disposed in the second sheet conveyance path 22.

  The image forming apparatus 100 further includes a conveyance switching member 81. The conveyance switching member 81 is provided in the vicinity of the communication portion 21 a between the first sheet conveyance path 21 and the second sheet conveyance path 22. The conveyance switching member 81 performs a first switching operation for guiding the sheet P sent in the sheet conveyance direction A from the sheet supply cassette unit 11 or the manual sheet supply unit 12 toward the first sheet conveyance path 21 (solid line in FIG. 1). And a second switching operation for guiding the sheet P sent in the sheet conveyance direction A from the sheet supply cassette unit 11 or the manual sheet supply unit 12 toward the second sheet conveyance path 22 in the sheet inversion path 61 (see FIG. 1 (see the broken line 1). Specifically, the conveyance switching member 81 is a guide member extending in the rotation axis direction of each roller, and is rotatable around the pivot shaft 81a along the rotation axis direction. The conveyance switching member 81 is driven by the switching drive unit 74 (see FIG. 2) via the drive transmission means 74a, so that the first switching operation and the second switching operation are switched.

  The sheet handle unit 63 further includes a reading handle operation for conveying the sheet P conveyed in the sheet conveyance direction A as it is in the second sheet conveyance path 22 when the conveyance switching member 81 is in the second switching operation state, It is also configured to perform a discharge handle operation in which the sheet P conveyed in the second sheet conveyance path 22 in the sheet reverse conveyance direction B is conveyed as it is. Specifically, the seat handle portion 63 is further driven to rotate in the reverse rotation direction (the direction of arrow D in FIG. 1) by being driven by the handle driving portion 73 via the drive transmission means 73a. Here, the sheet handle intermediate roller 63a rotates in the reverse direction D in the reading handle operation and sends out the sheet P in the second sheet conveyance path 22 in the sheet conveyance direction A. The sheet P in the second sheet conveyance path 22 is rotated in the rolling direction C and sent out in the sheet reverse conveyance direction B.

  Further, the sheet reversing roller unit 62 further conveys the sheet P conveyed in the sheet conveyance direction A from the sheet supply cassette unit 11 or the manual sheet supply unit 12 toward the sheet discharge path 52. It is also. Specifically, the sheet reversing roller unit 62 is further driven by the reversal driving unit 72 via the drive transmission unit 72a, so that the sheet P is conveyed in the sheet conveying direction A.

  Further, in the present embodiment, the conveyance switching member 81 is configured so that the sheet P conveyed in the sheet reverse conveyance direction B in the sheet reverse conveyance direction B can be discharged to the manual sheet supply port 12a in the second switching operation state. Has been. In this case, the second switching operation is also a switching operation that guides the sheet P sent in the sheet reverse conveyance direction B from the sheet reversing path 61 toward the sheet feeding port 12a for manual feeding. In the case where the manual sheet supply unit 12 includes the manual tray 12b and the manual roller unit 12c, when the sheet P is discharged from the manual sheet supply port 12a to the manual tray 12b, the manual roller unit 12c is routed to the sheet P. It can be located in the retracted position retracted from.

  In the present embodiment, the image sensor 90 is a contact image sensor. As the contact image sensor, a contact reading sensor generally used for reading an original in an image reading apparatus such as a scanner apparatus or a facsimile apparatus or a commercially available product called CIS (Contact Image Sensor) can be used. A sensor unit in which a SELFOC lens, an image reading sensor such as CMOS (Complementary Metal Oxide Semiconductor), and a light source such as a light emitting diode (LED) are combined can be exemplified. As a specific product, for example, a contact image sensor HE06G-W01 (manufactured by Canon Components Inc.) can be cited.

  In the present embodiment, the image sensor 90 includes the first image sensor 91 disposed on the printing side (here, the lower side) on one side of the both sides of the second sheet conveyance path 22 and the other side. And a second image sensor 92 disposed on the printing side (upper side in this case). That is, the first image sensor 91 is disposed at a position for reading one side of the sheet P conveyed in the sheet conveying direction A (the surface printed first in the image forming unit 30). The second image sensor 92 is arranged at a position for reading the other surface (back side) opposite to the other surface of the sheet P. Here, the first and second image sensors 91 and 92 are arranged so that the reading units 91 a and 92 a are displaced along the second sheet conveyance path 22.

  As shown in FIG. 2, the first and second image sensors 91 and 92 are connected to the input system of the control unit 40. The discharge drive unit 71, the reverse drive unit 72, the handle drive unit 73, and the switching drive unit 74 are connected to the output system of the control unit 40. The control unit 40 is also connected to the image forming unit 30.

  The control unit 40 includes a processing unit 41 such as a CPU (Central Processing Unit) and a storage unit 42. The storage unit 42 includes a storage memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and stores various control programs, necessary functions, tables, and various data. Specifically, in the image forming apparatus 100, the processing unit 41 of the control unit 40 loads and executes a print control program stored in advance in the ROM of the storage unit 42 on the RAM of the storage unit 42, thereby executing various components. It comes to control.

  The control unit 40 is configured to control the printing operation based on the reading results of the sheet P conveyed through the second sheet conveyance path 22 by the first and second image sensors 91 and 92.

  In the present embodiment, the control unit 40 is based on the reading results of the sheet P conveyed by the first and second image sensors 91 and 92 on the second sheet conveyance path 22 that constitutes a part of the sheet reversing path 61. When it is determined that there is an image on at least one surface of the sheet P, the image forming unit 30 performs concealment printing for concealing the image on the sheet P.

  Specifically, the controller 40 reads one of the sheets P conveyed by the first image sensor 91 based on the reading results of the sheets P conveyed by the first and second image sensors 91 and 92 on the second sheet conveying path 22. When it is determined that there is an image only on the surface (front surface), the image forming unit 30 performs concealment printing on the image on one surface of the sheet P, and then the sheet P is discharged to the sheet discharge port 51. Alternatively, the sheet is discharged to the manual sheet supply port 12a.

  Further, the control unit 40 determines that there are images on both sides of the sheet P based on the reading results of the sheet P conveyed by the second sheet conveyance path 22 by the first and second image sensors 91 and 92. In this case, concealment printing is performed by the image forming unit 30 on the image on one side of the sheet P, the sheet P is reversed by the sheet reversing conveyance unit 60 so that the front and back are reversed, and the other side of the sheet P is reversed. After concealment printing is performed on the front (back) image by the image forming unit 30, the sheet P is discharged to the sheet discharge port 51 or discharged to the manual sheet supply port 12 a.

  This hidden printing may be performed on the entire image of the sheet P or may be performed on a part of the image. As the concealment printing, for example, solid printing for painting an image recorded on the sheet P may be performed, or halftone printing for concealing the image recorded on the sheet P in a halftone dot shape may be performed.

  In the present embodiment, the control unit 40 performs concealment printing so that the image read by the first and second image sensors 91 and 92 is concealed with a size larger than the image by the image processor.

  Further, in the present embodiment, the control unit 40 has images on both sides of the sheet P based on the reading results of the sheet P conveyed by the second sheet conveyance path 22 by the first and second image sensors 91 and 92. If it is determined that there is no sheet, the sheet P is discharged from the sheet discharge port 51 to the discharge tray 54 or is discharged to the manual sheet supply port 12a without passing through the image forming unit 30.

  Note that when the control unit 40 determines that an image is present only on the other side of the sheet P read by the second image sensor 92, the control unit 40 removes the sheet P from the sheet discharge port without passing through the image forming unit 30. It may be discharged to 51 or discharged to the manual sheet supply port 12a. Further, when the control unit 40 determines that there is an image only on the other side read by the second image sensor 92 of the sheet P, the control unit 40 passes the image P through the image forming unit 30 without performing a printing operation. Is reversed so that the front and back sides are reversed by the sheet reversing conveyance unit 60, and the image on the other side of the sheet P is concealed by the image forming unit 30, and then the sheet P is fed to the sheet discharge port 51. The sheet may be discharged or may be discharged to the manual sheet supply port 12a.

  In the present embodiment, the image forming apparatus 100 is provided with an operation panel unit 110 (not shown in FIG. 1 but see FIG. 3 to be described later) that can be manually operated on the side surface of the manual sheet supply port. Yes.

  3 is a view of the image forming apparatus 100 shown in FIG. 1 as viewed from the side of the manual sheet supply port 12a.

  As shown in FIG. 3, the operation panel unit 110 includes a display panel (here, a liquid crystal display panel) 111. Specifically, the display panel 111 is a touch panel that can input position information of the display screen 111a by a touch operation on the display screen 111a.

  The display panel 111 is provided in the operation panel unit 110. The operation panel unit 110 is further provided with a start key 112 and a screen switching key 113 that act as operation members.

  As shown in FIG. 2, the start key 112 and the screen switching key 113 are connected to the input system of the control unit 40. The display panel 111 is connected to the output system of the control unit 40.

  The start key 112 is an operation key for instructing the control unit 40 to start a printing operation for hidden printing. The screen switching key 113 is a key for selecting various setting screens displayed on the display screen 111 a of the display panel 111.

  FIG. 4 is a diagram showing a setting screen of the display panel 111 that is switched by the screen switching key 113 in the operation panel unit 110. 4A shows the discharge port setting screen D1, FIG. 4B shows the hidden print setting screen D2, and FIG. 4C shows the hidden print type setting screen D3. Yes.

  When the screen switch key 113 is pressed by the operator, the control unit 40 sequentially displays the discharge port setting screen D1, the hidden print setting screen D2, and the hidden print type setting screen D3 on the display screen 111a.

  The discharge port setting screen D1 shown in FIG. 4A is a screen for setting sheet discharge to the sheet discharge port 51 or the manual sheet supply port 12a. When the screen switching key 113 is used to switch to the discharge port setting screen D1 shown in FIG. 4A, a discharge port discharge button D1a and a manual feed port discharge button D1b are displayed on the discharge port setting screen D1.

  When the operator performs a touch operation on the discharge port discharge button D1a, a discharge port discharge mode for discharging the sheet P to be discharged to the sheet discharge port 51 is set, while the manual input port discharge button D1b is touched by the operator. When operated, a manual port discharge mode is set in which the sheet P to be discharged is discharged from the sheet reversing path 61 to the manual sheet supply port 12a.

Further, the control unit 40 performs the whole concealment printing for performing concealment printing on the entire image of the sheet P read by the image sensor 90 and the concealment printing for a part of the image of the sheet P read by the image sensor 90. It is possible to selectively switch between partial concealment printing to be performed. Specifically, the concealment print setting screen D2 shown in FIG. 4B is a screen for setting whether to perform concealment printing on all or part of the sheet image. When the hidden print setting screen D2 shown in FIG. 4B is switched by the screen switching key 113, the entire print button D2a and the partial print button D2b are displayed on the hidden print setting screen D2. As described above, the entire hidden printing and the partially hidden printing can be selectively switched, so that the entire hidden printing and the partially hidden printing can be selected as necessary.

  When the operator touches the entire print button D2a, an entire hidden print mode is set in which hidden printing is performed on the entire image of the sheet P read by the first and second image sensors 91 and 92. On the other hand, when the partial print button D2b is touched by the operator, a partial concealment print mode for performing concealment printing on a part of the image of the sheet P read by the first and second image sensors 91 and 92 is set. The

  Here, when the partial concealment printing mode is set, the control unit 40 temporarily displays the image of the sheet P read by the first and second image sensors 91 and 92 on the display screen 111a so as to be partially selectable. After the part to be concealed is selected by the touch operation by the operator, concealment printing is performed on the sheet P so as to conceal the image corresponding to the selected part. Furthermore, the control unit 40 newly prints the image concealed by the concealment printing on another sheet. For this reason, when the partial concealment print mode is set, another sheet print button D2c is displayed on the concealment print setting screen D2.

  When the operator performs a touch operation on the separate sheet print button D2c, a separate sheet print mode is set in which an image concealed by concealment printing is printed on another sheet.

The concealment printing includes solid printing that fills an image and halftone printing that conceals the image in a halftone dot pattern, and the control unit 40 can selectively switch between solid printing and halftone dot printing. . Specifically, the concealment print type setting screen D3 shown in FIG. 4C is a screen for setting solid print or halftone print of concealment printing. When the hidden print type setting screen D3 shown in FIG. 4C is switched by the screen switching key 113, a solid print button D3a and a halftone print button D3b are displayed on the hidden print type setting screen D3.

  When the solid print button D3a is touch-operated by the operator, a solid print mode for filling the image recorded on the sheet P is set, while when the halftone print button D3b is touch-operated by the operator, the sheet A halftone dot printing mode for hiding the image recorded in P in a halftone dot shape is set.

  In addition, the operation panel unit 110 is further provided with an up key 114a and a down key 114b that act as operation members.

  When the up key 114a is pressed by the operator, the control unit 40 scrolls the image of the sheet P displayed on the display screen 111a downward so that the upper information is displayed, while the operator presses the down key. When 114b is pressed, the image of the sheet P displayed on the display screen 111a is scrolled upward so that lower information is displayed.

(Concealment printing operation)
Next, a specific operation of hidden printing will be described. FIG. 5 is a diagram illustrating an operation example of concealment printing by the image forming apparatus 100 illustrated in FIG. 5A shows a state in which the sheet P is read by the first and second image sensors 91 and 92, and FIG. 5B shows a state in which the rear end of the sheet P uses the second image sensor 92. FIG. 5C shows a state in which the sheet P is concealed and printed.

  When the operator presses the start key 112, first, as shown in FIG. 5A, the conveyance switching member 81 is switched to the second switching operation, and the sheet handle intermediate roller 63a of the sheet handle portion 63 is rotated in the reverse direction D. It will be in a state of rotating. In this state, the sheet P supplied from the sheet supply cassette unit 11 or the manual sheet supply unit 12 (manual sheet supply unit 12 in the illustrated example) is guided to the second sheet conveyance path 22 by the conveyance switching member 81, and the sheet handle The sheet 63 is conveyed in the sheet conveying direction A to the first and second image sensors 91 and 92 by the reading handle operation of the unit 63.

  At this time, when the leading edge of the sheet P passes through the reading unit 91a of the first image sensor 91, image reading by the first image sensor 91 is started, and when the leading end of the sheet P passes through the reading unit 92a of the second image sensor 92, the second image sensor 92 is started. Start image reading by.

  Further, as shown in FIG. 5B, the sheet P that has passed through the sheet handle portion 63 is conveyed by the sheet reversing roller portion 62 until the rear end passes through the first and second image sensors 91 and 92.

  At this time, when the rear end of the sheet P passes through the reading unit 91a of the first image sensor 91, the image reading by the first image sensor 91 is finished, and when the rear end of the sheet P passes through the reading unit 92a of the second image sensor 92, the second image sensor. The image reading by 92 is finished. The read image data is stored in the storage unit 42 of the control unit 40.

  The reading start timing and reading end timing are the same as those used in the conventional image reading apparatus, and detailed description thereof is omitted here.

  Here, the conveying operation of the sheet P will be described separately for a case where there is an image on only one side, a case where there is an image on both sides, and a case where there is no image on both sides.

<When there is an image only on one side of the sheet P>
Based on the reading results of the first and second image sensors 91 and 92, when there is an image on only one side of the sheet P, the first sheet reversing guide roller 62a and the second sheet reversing guide roller 62b are reversely conveyed by the sheet. The sheet handle intermediate roller 63a of the sheet handle portion 63 rotates in the forward direction C while rotating in the direction B. In this state, as shown in FIG. 5C, the sheet P is conveyed in the sheet reverse conveyance direction B by the sheet reverse roller unit 62, and passes through the pre-registration conveyance path 31 by the reverse handle operation of the sheet handle unit 63. After being conveyed to the registration roller unit 32, concealment printing is performed on one side of the sheet P from the image forming unit 30.

(When discharging to the discharge tray)
When the discharge port discharge mode is set, the concealed printed sheet P is conveyed in the sheet conveyance direction A by the sheet discharge roller unit 53 and discharged from the sheet discharge port 51 to the discharge tray 54.

(When discharging to the bypass tray)
On the other hand, when the manual feed port discharge mode is set, after the rear end of the sheet P that has been concealed printed by the sheet discharge roller unit 53 passes through the branch portion 52a of the sheet discharge path 52 with the sheet reversing path 61, The sheet is conveyed in the sheet reverse conveyance direction B and is shifted to the sheet reversal path 61. At this time, the first sheet reversing guide roller 62a and the second sheet reversing guide roller 62b rotate in the sheet reverse conveying direction B, and the sheet handle intermediate roller 63a of the sheet handle portion 63 rotates in the normal rotation direction C. Is done. In this state, the sheet P is conveyed in the sheet reverse conveyance direction B by the sheet reversing roller unit 62, and the communication unit between the first sheet conveyance path 21 and the second sheet conveyance path 22 is performed by the discharge handle operation of the sheet handle unit 63. The sheet is discharged from 21a through the first sheet conveying path 21 to the manual sheet supply port 12a.

<When there are images on both sides of the sheet P>
Based on the reading results of the first and second image sensors 91 and 92, when there are images on both sides of the sheet P, concealment printing is performed on one side of the sheet P in the same manner as when there is an image only on one side. I do. Then, after the sheet P that has been concealed printed on one side is reversed in the same manner as the double-sided printing described above, concealed printing is also performed on the other side of the sheet P from the image forming unit 30.

  If there is no image on one side of the sheet P and an image on the other side, the sheet P is passed through the image forming unit 30 without performing concealment printing on the other side. The image forming unit 30 may perform concealment printing on the other side via the sheet discharge path 52, the sheet reversing path 61, the sheet handle part 63, the pre-registration conveyance path 31, and the registration roller part 32.

(When discharging to the discharge tray)
When the discharge port discharge mode is set, the concealed printed sheet P is discharged from the sheet discharge port 51 to the discharge tray 54 in the same manner as when the image is present only on one side of the sheet P. .

(When discharging to the bypass tray)
On the other hand, when the manual feed port discharge mode is set, the cover-printed sheet P is discharged to the manual feed sheet supply port 12a in the same manner as when an image is present only on one side of the sheet P.

<When there are no images on both sides of the sheet P>
If there is no image on both sides of the sheet P based on the reading results by the first and second image sensors 91 and 92, the sheet P is discharged outside without passing through the image forming unit 30.

(When discharging to the discharge tray)
That is, when the discharge port discharge mode is set, the sheet P read by the first and second image sensors 91 and 92 is conveyed in the sheet conveyance direction A by the sheet reverse roller unit 62 and the sheet discharge roller unit 53. The sheet is directly discharged from the sheet discharge port 51 to the discharge tray 54.

(When discharging to the bypass tray)
On the other hand, when the manual feed port discharge mode is set, the sheet P read by the first and second image sensors 91 and 92 is conveyed in the sheet reverse conveyance direction B by the sheet reverse roller unit 62, and the sheet handle unit 63. Is discharged from the communicating portion 21a of the first sheet conveyance path 21 to the second sheet conveyance path 22 through the first sheet conveyance path 21 to the manual sheet supply port 12a.

  Even when there is no image on one side of the sheet P and there is an image on the other side, the sheet P can be discharged to the outside without going through the image forming unit 30.

  Next, the hidden printing will be described separately for the case where the entire hidden printing mode is set and the case where the partially hidden printing mode is set.

[Wide print mode]
FIG. 6 is a diagram for explaining the entire concealment printing for the entire image of the sheet P on which the image information is recorded. FIG. 6A shows a state where the cover P is not subjected to the concealment printing. FIG. 6B shows a state in which solid printing is performed as concealment printing for the sheet P. FIG. 6C shows a state in which halftone printing is performed as concealment printing for the sheet P.

  When the entire concealment printing mode for performing concealment printing is set for the entire image of the sheet P (see FIG. 6A), when the solid print mode is set, solid printing is performed ( If the halftone printing mode is set, halftone printing is performed (see FIG. 6C). For example, when the image on the sheet P is a character, the text on the page may be framed as a group of images and the whole may be concealed. However, the amount of printing material (toner in this case) used for concealment may be reduced. From the viewpoint of further reduction, it is possible not to perform concealment printing between each paragraph by performing frame concealment printing by paragraph unit, or concealment printing between each line by performing frame concealment printing by concealing line unit by line. You may make it not. Alternatively, the concealment printing may not be performed between characters by cutting out a frame in character units and performing concealment printing. For recognition of sentences, paragraphs, lines, and characters, conventionally known image processing techniques can be used, and detailed description thereof is omitted here.

  Specifically, for image data stored in the storage unit 42, an image such as a character or a graphic is identified by an image processor, for example, for hiding the image of the sheet P in FIG. A solid image or a halftone image is created.

  Here, the solid printing and the halftone dot printing are larger in size by about 1 mm than the size of the image (outer shape) such as characters and figures to be concealed in consideration of the shift (for example, about ± 0.5) due to the conveyance of the sheet P. Preferably there is.

  When the image reading by the second image sensor 92 is completed at a position where the rear end of the sheet P deviates from the second image sensor 92 on the downstream side in the sheet conveying direction A (see FIG. 5B), the sheet P is turned into the sheet reversing roller. The sheet is conveyed in the sheet reverse conveyance direction B by the unit 62 and conveyed to the image forming unit 30 via the sheet handle intermediate roller 63a (see FIG. 5C). In the image forming apparatus 30, the sheet P transported from the pre-registration transport path 31 to the PS roller 32 a is synchronized with the image of the sheet P by the PS roller 32 a, and then the image forming engine unit 33 The toner of the created image is transferred by the transfer roller 33e, concealed with toner so as to overlap the image portion read in advance, and concealed printing is performed via the fixing unit.

  Here, the solid printing mode is set in the initial setting. Normally, when solid printing is performed, as shown in FIG. 6B, the dot printing button D3b is used to suppress toner consumption. By setting the halftone printing mode according to (see FIG. 4C), halftone printing as shown in FIG. 6C can be performed. By the way, in the case of an A4 size original and a printing rate of 5%, the toner consumption is generally 0.02 g. If halftone printing is used as opposed to solid printing, for example, toner consumption can be reduced by half.

  Note that solid printing and halftone printing are the same in the case of partial concealment printing described below.

[Partial concealment printing mode]
When the partial concealment printing mode is set, the image reading by the second image sensor 92 is finished, and the sheet reverse roller unit 62 removes the sheet P at a position where the rear end of the sheet P deviates from the second image sensor 92. To temporarily stop.

  Then, the image of the sheet P read by the first and second image sensors 91 and 92 is displayed on the display screen 111 a of the display panel 111.

  FIG. 7 is a diagram showing the display screen 111a of the display panel 111 on which an image read from the sheet P is displayed and various keys 112, 113, 114a, and 114b arranged around the display screen 111a. FIG. 7A shows a screen on which an image read from the sheet P is displayed, and FIG. 7B shows a screen on which an image read from the sheet P is partially selected.

  The operator selects the portion on the display screen 111a read from the sheet P by erasing a portion to be concealed (see FIG. 7A) by a touch operation. For example, a portion to be concealed in the display image is selected by surrounding it with a frame by a touch operation (specifically, touching the screen with a screen position specifying member having a sharp tip like a pen (screen position specification)). It may be. In this case, the inside of the frame may be filled (see FIG. 7B). Note that the image displayed on the display screen 111a can be scrolled by pressing the up / down keys 114a and 114b.

  When a part to be concealed is selected by the operator and the start key 112 is pressed, concealment printing is performed on the read sheet P so as to conceal an image corresponding to the selected part.

  In this case, when the separate sheet printing mode is set, the image concealed by concealment printing is printed on another new sheet (for example, a blank sheet supplied from the sheet supply cassette unit 11 or the manual sheet supply unit 12). To do.

  As described above, the image forming apparatus 100 according to the present embodiment is configured to perform, for example, a printing process that conceals the image information on the sheet P on which highly confidential image information is recorded. be able to.

  By the way, the main purpose of image forming apparatuses is to print image information such as characters and graphics. However, the image forming apparatus is entirely applied to the entire sheet surface regardless of the presence or size of image information recorded on the sheet. If the whole surface concealing printing is performed, image information such as characters and figures can be concealed easily and easily. Therefore, this whole surface concealment printing is a simple method in that image information such as characters and figures cannot be understood by others. However, if any sheet is subjected to a printing process and full concealment printing is performed on the entire sheet surface, the amount of concealment printing material (toner in this case) is increased, which is too uneconomical. .

  In consideration of recent environmental problems, it is not preferable to incinerate a sheet on which confidential information is recorded, and it is desired to use it effectively instead of simply breaking it.

  In this regard, according to the image forming apparatus 100, an image for concealment printing (in this case, a concealment larger than the image of the read sheet P is used based on the image of the sheet P read by the first and second image sensors 91 and 92. Print image), and the sheet P is conveyed to the image forming unit 30 and then printed on the image of the sheet P, so that images such as characters and figures on the sheet P can be concealed. Confidentiality can be easily achieved. In addition, there is no bulkiness due to shredder cutting, and a sheet that may have been incinerated conventionally can be collected as a sheet for recycling.

  In the present embodiment, the sheet reversing path 61 for double-sided printing is used as a sheet conveying path for reading the image of the sheet P by the first and second image sensors 91 and 92 without providing a separate sheet conveying path. Therefore, without causing an increase in the size of the apparatus 100, it is possible to perform a printing process on the sheet P on which the image information is recorded so that the image information cannot be understood by others.

  In the present embodiment, the two image sensors 91 and 92 are respectively arranged on both sides of the second sheet conveyance path 22 and both sides of the sheet are read simultaneously. Therefore, both sides of the sheet P are fed by one sheet supply. Can be processed.

By the way, the image sensor normally receives reflected light obtained by irradiating the sheet with light. In this case, a sheet that easily transmits light, such as a thin sheet, has two images. If the reading sections of the sensors are facing each other, there may be a case where an individual image sensor reads a transmission image through which an image on the side opposite to the reading side is transmitted due to the effect of light transmission through the sheet. . If it does so, the image of the surface which should read the sheet cannot be read accurately.
In this regard , in the present embodiment, since the reading units 91a and 92a of the two image sensors 91 and 29 are displaced along the second sheet conveyance path 22, light is transmitted like a thin sheet. Even an easy-to-use sheet can be hardly affected by light transmission, an image on the surface to be read of the sheet P can be read with high accuracy, and image identification on both sides of the sheet P can be accurately performed.

  In the present embodiment, when the two image sensors 91 and 92 recognize that there are images on both sides of the sheet P, the image forming unit 30 performs concealment printing on one side and then the sheet P Is reversed so that the front and back are reversed by the sheet reversing path 61, and the concealing printing is performed on the other side, so that the concealing printing of the double-sided image can be performed with one sheet supply.

  On the contrary, when there is no image on both sides of the sheet P, the sheet P is stained with toner in the image forming engine unit 33 or discharged in the fixing unit 34 by discharging to the outside without passing through the image forming unit 30. The sheet P can be discharged without being affected by heat or pressure. By doing so, even if white paper is mixed in the sheet supply unit 10, it is possible to correctly sort, and it is possible to eliminate the waste of the sheet.

  In this embodiment, if the manual feed outlet mode is selected, the sheet P to be discharged or the reading by the first and second image sensors 91 and 92 based on the reading result by the first and second image sensors 91 and 92 is selected. Since the sheet P to be discharged after the printing operation based on the result can be discharged from the sheet reversing path 61 to the sheet feeding port 12a for manual feeding, confusion with a sheet discharged by a normal printing operation other than the concealment printing is possible. It can be avoided and the convenience can be improved accordingly.

In the present embodiment, once the partial concealment printing mode in which an image read from the sheet P is displayed on the display panel 111 is selected, a portion to be concealed can be easily selected by touching the display screen 111a. Specifically, the operator can easily select only images such as texts and figures that the operator wants to conceal, and can select and leave the image of the part that does not need to be concealed arbitrarily. Is possible.

  In the present embodiment, since the concealed image is newly printed on another sheet (for example, a blank sheet), the concealed image and the concealment with respect to the sheet P read by the first and second image sensors 91 and 92 are printed. While recording an image that has not been performed, it is possible to record only an image of a portion that the operator wants to conceal from another sheet.

  Further, in the present embodiment, the image of the sheet P is concealed with a larger area than the image of the sheet P read by the first and second image sensors 91 and 92. The image information is understood by others with a small area to be concealed on the sheet on which the information is recorded (that is, with the amount of the printing material (toner) used for concealment being kept low). It becomes possible to perform printing processing that cannot be performed.

  Further, in the present embodiment, when performing solid printing, it is possible to reliably hide an image to be hidden. On the other hand, when halftone printing is performed, the amount of printing material used for concealment can be reduced while maintaining the concealability of the image to be concealed.

  In the present embodiment, since the solid print mode and the halftone print mode can be switched, the solid print can be selected when the operator wants to prioritize the concealment, and the halftone print can be selected when priority is given to the toner reduction. Can be selected.

Further, in this embodiment, since use of the contact image sensor as the first and second image sensors 91 and 92, can be disposed a contact image sensor by using the extra space of the existing structure, thereby, the The above-described effects can be obtained while maintaining the overall size of the image forming apparatus 100 , that is, without increasing the size of the image forming apparatus 100.

(Other embodiments)
Next, another example of the image forming apparatus 100 shown in FIG. 1 will be described. FIG. 8 is a schematic sectional view showing another example 200 of the image forming apparatus 100 shown in FIG. FIG. 9 is a schematic side view showing the display panel 210 of the image forming apparatus 200 shown in FIG. In FIG. 8 and FIG. 9, the same components as those of the image forming apparatus 100 shown in FIG. In FIG. 8, the conveyance switching member 81 is not shown.

  An image forming apparatus 200 illustrated in FIG. 8 is obtained by integrating the image forming apparatus 100 illustrated in FIG. 1 and a display panel 210 of a computer (here, a personal computer). That is, the image forming apparatus 200 is the same as the image forming apparatus 100 shown in FIG. 1 except that a display panel 210 of a personal computer is provided instead of the display panel 111 and a control unit of the personal computer is provided as the control unit 40.

  The image forming apparatus 200 includes a personal computer having a display panel (here, a liquid crystal display panel) 210, and the display panel 210 is opened and closed above the image forming unit 30 (here, with respect to the image forming unit 30). Possible).

  8A shows a state where the display panel 210 of the image forming apparatus 200 is closed, and FIG. 8B shows a state where the display panel 210 of the image forming apparatus 200 is opened.

  In this image forming apparatus 200, as shown in FIG. 8A, the display panel 210 is configured to cover the upper surface of the image forming unit 30, and the display panel 210 is erected as shown in FIG. 8B. Thus, the operator can visually recognize the display screen 210a satisfactorily.

  Specifically, with respect to the image forming unit 30, the display panel 210 extends along the rotation axis direction of each roller at the sheet supply side end in the sheet conveyance direction A (the end opposite to the sheet discharge port 51). The pivot shaft 211 is supported so as to be rotatable.

  The image forming apparatus 200 further includes a discharge tray 220 provided in the image forming unit 30 above the image forming unit 30 instead of the discharge tray 54 of the image forming apparatus 100 shown in FIG. The discharge tray 220 may be provided so as to be openable and closable with respect to the image forming unit 30.

  The display panel 210 may store the discharge tray 220 on the back surface. Specifically, the discharge tray 220 is housed on the back surface of the display panel 210 in a closed state (see FIG. 8A), and the display panel 210 in an open state is formed from the vicinity of the sheet discharge port 51 to form an image. You may support in the state inclined with respect to the front end side of the part 30 (refer FIG.8 (b)).

  The control unit 40 in the image forming apparatus 200 is a control unit that constitutes a personal computer.

  FIG. 9A shows a state where an image read from the sheet P is displayed on the display panel 210. FIG. 9B shows a state in which a portion to be hidden is selected for the image displayed on the display panel 210. FIG. 9C shows a state in which additional information is inserted into the image displayed on the display panel 210.

  The image forming apparatus 200 controls various components by reading and executing a print control program from a computer-readable recording medium M on which the print control program is recorded.

  The print control program includes print control means for controlling the printing operation based on the reading results of the personal computer by the first and second image sensors 91 and 92 of the sheet P conveyed on the second sheet conveyance path 22. It functions as a means. Further, the printing control program may cause the personal computer to function so as to perform a normal printing operation.

  The print control unit can execute the above-described printing operation. For example, when the printing control unit determines that there is an image on the sheet P based on the reading results of the sheet P conveyed through the second sheet conveyance path 22 by the first and second image sensors 91 and 92, The sheet P may include a concealment printing unit that performs concealment printing for concealing the image by the image forming unit 30.

  Here, the concealment printing means temporarily displays the image of the sheet P read by the first and second image sensors 91 and 92 on the display screen 210a, and after selecting a portion to be concealed by manual operation, the sheet P The concealment printing is performed on P so as to conceal the image corresponding to the selected portion.

  Specifically, the printing control unit temporarily displays the image of the sheet P read by the first and second image sensors 91 and 92 on the display panel 210 (see FIG. 9A) and displays it on the display screen 210a. A portion to be concealed is selected by an operating means such as a pointing device (so-called mouse) (not shown) for the displayed image (see FIG. 9B).

  In addition, the print control unit temporarily displays an image of the sheet P read by the first and second image sensors 91 and 92 on the display screen 210a, and at least one of characters and figures is displayed on the image displayed on the display screen 210a. Includes image editing means for inserting additional information including (see FIG. 9C). Here, the image editing unit prints the additional information on the read sheet P by the image forming unit 30.

  According to the image forming apparatus 200 described above, since the display panel 210 in the personal computer is provided on the upper part of the image forming unit 30, the image of the sheet P read by the first and second image sensors 91 and 92 is displayed. It can be displayed on a relatively large display screen of the panel 210, and the operation can be performed in such a way that the operator can easily see it. In addition, since the display panel 210 can be opened and closed with respect to the image forming unit 30, the image forming apparatus 200 can be made compact. Furthermore, since the control unit 40 is a control unit that constitutes a personal computer, the control unit can control the printing operation of the image forming apparatus 200. For example, the image displayed on the screen 210a of the display panel 210 can be subjected to various image editing such as processing by the image editing means.

  Further, by inserting additional information including at least one of characters and figures into the image displayed on the display screen 210a, and printing the inserted additional information on the read sheet P by the image forming unit 30, the first and As shown in FIG. 9B, the image of the sheet P as shown in FIG. 9A read by the second image sensors 91 and 92 is not only subjected to the concealment printing as shown in FIG. As shown in FIG. 4, a new printed matter can be obtained in which additional information such as a date and a guide map is added in addition to the already recorded image information.

  In the image forming apparatuses 100 and 200 according to the present embodiment, the image sensor 90 replaces or in addition to the second sheet conveyance path 22, the first sheet conveyance between the sheet supply unit 10 and the image forming unit 30. You may provide in the path | route 21. FIG. Alternatively, the image sensor 90 may be provided in the sheet supply unit 10.

  In addition, the image forming apparatuses 100 and 200 according to the present embodiment have a double-sided printing function, but may have only a single-sided printing function. In this case, the image sensor 90 can be provided in the first sheet conveyance path 21 or the sheet supply unit 10.

  In the image forming apparatuses 100 and 200 of the present embodiment, the image forming unit 30 performs printing by an electrophotographic image forming process. However, the present invention is not limited to this. An image forming unit that performs printing by a forming process may be used.

DESCRIPTION OF SYMBOLS 10 Sheet supply part 12a Manual sheet supply port 20 Sheet conveyance path 30 Image forming part 40 Control part 50 Sheet discharge part 51 Sheet discharge part 61 Sheet inversion path 90 Image sensor 91 First image sensor 92 Second image sensor 100 Image formation Device 110 Display panel 111a Display screen 200 Image forming device 210 Display panel M Recording medium P Sheet

Claims (14)

A sheet feeding unit for supplying sheets, a sheet conveying path which the sheet is conveyed to be fed from the sheet feeding unit, and an image forming unit that prints the conveyed sheet conveying path sheet, the control of the printing operation An image forming apparatus including a control unit
An image sensor that reads an image of a sheet conveyed through the sheet conveyance path and a sheet printed on one side are reversed so that the front and back are reversed by the sheet reversal path, and then printing is performed on the other side. With double-sided printing function ,
The sheet conveyance path includes a first sheet conveyance path that is a path between the sheet supply unit and the image forming unit, and a second sheet conveyance path that forms a part of the sheet reversal path,
The image sensor is provided in the second sheet conveyance path in the sheet reversing path,
Wherein the control unit reads by the image sensor in the second and conveyed to the sheet conveying path wherein the sheet second sheet conveying path in once the sheet reversing path supplied thereto sheet from the sheet supply unit, said first 2 based on the reading result by the image sensor of the sheet conveyed through the sheet conveying path, if it is determined that there is an image on the sheet, the second said the sheet in the sheet conveying path first sheet conveying An image forming apparatus configured to perform concealment printing for concealing the image by the image forming unit on the sheet conveyed to a path . The image forming apparatus according to claim 1 .
When the control unit determines that there is no image on both sides of the sheet based on the reading result of the sheet conveyed by the image sensor on the second sheet conveyance path, the control unit does not pass through the image forming unit. An image forming apparatus for discharging a sheet to the outside. The image forming apparatus according to claim 1 or claim 2,
When the control unit determines that there are images on both sides of the sheet based on a reading result of the sheet conveyed by the image sensor on the second sheet conveyance path, the sheet is conveyed to the first sheet conveyance path. Then , after performing concealment printing to conceal the image of the one side by the image forming unit with respect to one side of the sheet, the sheet is reversed so that the front and back are reversed by the sheet reversal path, An image forming apparatus, wherein concealment printing is performed on the other side of the sheet by the image forming unit to conceal an image on the other side. The image forming apparatus according to any one of claims 1 to 3,
When the control unit determines that there is an image on one side of the sheet based on a reading result of the sheet conveyed by the image sensor on the second sheet conveyance path, the control unit transfers the sheet to the first sheet conveyance path. The image forming apparatus performs concealment printing on the one side of the sheet by the image forming unit so as to conceal the image on the one side. The image forming apparatus according to any one of claims 1 to 4, wherein:
When the control unit determines that there is no image on one side of the sheet and an image on the other side based on the reading result of the sheet conveyed by the image sensor on the second sheet conveyance path. Transports the sheet to the first sheet transport path, passes the image forming unit without performing concealment printing on the one side, and then reverses the sheet by the sheet reversal path. The image forming apparatus is configured to perform concealment printing for concealing the image on the other side of the other side of the sheet by the image forming unit. The image forming apparatus according to any one of claims 1 to 5 , wherein:
The image sensor, the image forming apparatus, wherein the in between the second sheet conveying path in the sheet reverse path is two image sensors which are arranged on both sides. The image forming apparatus according to any one of claims 1 to 6,
The sheet supply unit has a manual sheet supply port, and is configured to discharge the sheet conveyed through the sheet reversing path from the manual sheet supply port to the outside.
The control unit discharges a sheet to be discharged based on a reading result by the image sensor or a sheet to be discharged after a printing operation based on a reading result by the image sensor from the sheet reversing path to the manual sheet supply port. An image forming apparatus. The image forming apparatus according to claim 7.
A sheet discharge unit having a sheet discharge port for discharging the sheet to the outside;
The control unit is capable of selectively switching whether to discharge the sheet to be discharged to the sheet discharge port or to discharge from the sheet reversal path to the manual sheet supply port. An image forming apparatus. The image forming apparatus according to any one of claims 1 to 8,
A display panel that displays an image of the sheet read by the image sensor;
The control unit temporarily displays the image of the sheet read by the image sensor on the display panel so that the image can be partially selected, and after the portion to be hidden is selected by human operation, the selected image is selected for the sheet. An image forming apparatus that performs the concealment printing so as to conceal an image corresponding to the portion. The image forming apparatus according to any one of claims 1 to 9,
The control unit performs the concealment printing on a part of the image of the sheet read by the image sensor, and newly prints the image concealed by the concealment printing on another sheet. Forming equipment. The image forming apparatus according to any one of claims 1 to 1 0,
A display panel that displays an image of the sheet read by the image sensor;
The control unit temporarily displays an image of a sheet read by the image sensor on the display panel, and inserts additional information including at least one of characters and figures into the image displayed on the display panel. Image forming apparatus. The image forming apparatus according to any one of claims 1 to 11 ,
A computer having a display panel;
The display panel in the computer is provided on an upper part of the image forming unit,
An image forming apparatus, wherein the control unit is a control unit constituting the computer. The computer in the image forming apparatus according to claim 12 , wherein the sheet supplied from the sheet supply unit is once transported to the second sheet transport path in the sheet reversing path, and the sheet is transported to the second sheet transport path. the reading by the image sensor, the second and based on the reading result by the image sensor of the sheet conveyed through the sheet conveying path, if it is determined that there is an image on the sheet, the second sheet transport path in The sheet is conveyed to the first sheet conveyance path, and the sheet is caused to function as a unit including a concealment printing unit that performs concealment printing for concealing the image by the image forming unit. program. A computer-readable recording medium on which the printing control program according to claim 13 is recorded.

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