Patent Description:
When thick paper is used as a document to be read by an automatic document conveyance device, a jam easily occurs because a load on a conveyance roller becomes higher at a curved portion of a conveyance path. On the other hand, when thin paper is used as a document, because the weight of the document is light, it takes time for the document discharged to a sheet discharging unit to completely settle, and the rear end of a document collides with the leading end of a subsequent document. Such collision leads to a jam and a stack failure.

For solving such problems, there has been conventionally known an apparatus that detects the thickness of a document using a sensor and varies a conveyance speed of the document in accordance with the detected thickness (<CIT>).

<CIT> discloses an image reading apparatus as claimed in the pre-characterizing portion of claim <NUM>.

An automatic document conveyance device that prompts a user to set the thickness of a document by the user placing the document on a document tray of the. automatic document conveyance device when a copy screen is being displayed is proposed. The automatic document conveyance device can thereby recognize the thickness of a document without using a sensor.

Nevertheless, depending on the types of screens being displayed, some screens are undesired to be switched when a document is placed.

For example, such screens include a screen for notifying a way of clearing a paper jam. Because the user clears a paper jam while viewing the screen, the clearing of the paper jam is disturbed if the screen is hidden upon the placement of a document onto a document tray.

According to a first aspect of the present invention, there is provided an image reading apparatus as specified in claims <NUM> to <NUM>. According to a second aspect of the present invention, there is provided a control method as specified in claim <NUM>. According to a third aspect of the present invention, there is provided a storage medium as specified in claim <NUM>.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. Each of the embodiments of the present invention described below can be implemented solely or as a combination of a plurality of the embodiments or features thereof where necessary or where the combination of elements or features from individual embodiments in a single embodiment is beneficial.

A first exemplary embodiment will be described. <FIG> is a diagram illustrating an external appearance example of an image forming apparatus serving as an example of an image reading apparatus.

The image forming apparatus according to the present exemplary embodiment includes an image reading unit <NUM> and an image forming unit <NUM>.

The image reading unit <NUM> converts information regarding an image on a document into an electrical signal by inputting reflected light obtained by exposing and scanning the image with light emitted from an illumination lump, to a linear image sensor (charge-coupled device (CCD) sensor). The image reading unit <NUM> further converts the electrical signal into a luminance signal including colors of red (R), green (G), and blue (B), and outputs the luminance signal to a controller of the image forming apparatus as image data.

The document is set onto a document installation tray <NUM> of an automatic document feeder (hereinafter, "ADF") <NUM>. If a user issues an execution instruction for reading processing via an operation unit of the image forming apparatus, the controller of the image forming apparatus transmits a document reading instruction to the image reading unit <NUM>. Upon receipt of the document reading instruction, the image reading unit <NUM> feeds documents from the document installation tray <NUM> of the ADF <NUM> one by one, and performs a reading operation of the documents. Alternatively, the user can also perform the read operation of documents by placing the documents on a platen glass to be described below.

The image forming unit <NUM> is an image forming device that forms an image onto a sheet based on image data received from a controller unit <NUM>.

An image forming method according to the present exemplary embodiment is an electrophotographic method that uses a photosensitive drum and a photosensitive belt. The image forming unit <NUM> includes, as a sheet feeding unit <NUM>, a plurality of cassettes adapted to different sheet sizes or different sheet orientations. A printed sheet is discharged to a sheet discharging unit <NUM>. A finisher unit <NUM> performs postprocessing such as stapling or punching processing on the sheet based on a setting made by the user.

<FIG> is a cross-sectional view schematically illustrating a configuration example of the image reading unit <NUM> of the ADF <NUM> according to the present exemplary embodiment.

An operation of the ADF <NUM> will be described with reference to <FIG>. The ADF <NUM> illustrated in <FIG> includes the document installation tray <NUM>, a separation pad <NUM>, and a sheet feeding roller <NUM>. A document bundle S including one or more document sheets is stacked on the document installation tray <NUM>. The separation pad <NUM> prevents the document bundle S from protruding from the document installation tray <NUM> and moving forward to a downstream side before a conveyance start of the documents. The ADF <NUM> further includes a document detection sensor <NUM>, a distance measuring sensor <NUM>, and a separation sensor <NUM>. The document detection sensor <NUM> detects that the document bundle S is stacked on the document installation tray <NUM>. The distance measuring sensor <NUM> measures a distance from the uppermost surface of the document bundle S. The separation sensor <NUM> detects that a document has passed through a separation roller <NUM>. The document detection sensor <NUM> may be provided below a document and detect that the document is placed. The sheet feeding roller <NUM> falls onto the document surface of the document bundle S stacked on the document installation tray <NUM> and rotates. The uppermost document of the document bundle S is thereby fed. The one document conveyed by the sheet feeding roller <NUM> is separated from the other documents by the function of the separation roller <NUM> and the separation pad <NUM>. The separation is implemented by a known retard separation technique. At this time, if the separation sensor <NUM> does not detect a document after a certain period of time (t1) elapses from a conveyance start, the driving of the sheet feeding roller <NUM> is stopped. The certain period of time (t1) until the driving is stopped is set in view of a time it takes for a document to reach the separation sensor <NUM> from a conveyance start, which is predicted in accordance with a conveyance speed, further taking into account an adequate delay time.

The document separated by the separation roller <NUM> and the separation pad <NUM> is conveyed to a registration roller <NUM> by a conveyance roller <NUM>, and the document collides with the registration roller <NUM>. The document is thereby formed into a loop shape, and the skew of the document in the conveyance is corrected. A sheet feeding path is disposed on the downstream side of the registration roller <NUM>. The feeding path conveys the document that has passed through the registration roller <NUM>, toward a moving document reading glass <NUM>.

The document fed to the sheet feeding path is fed onto a platen by a large roller <NUM> and a conveyance roller <NUM>. At this time, the large roller <NUM> contacts the moving document reading glass <NUM>. The document conveyed by the large roller <NUM> passes through a conveyance roller <NUM>, moves between a roller <NUM> and a moving glass, and is discharged to a document discharging tray <NUM> via a sheet discharging flapper and a sheet discharging roller <NUM>.

The ADF <NUM> illustrated in <FIG> reads a rear surface image of a document by reversing the document. By reversing the sheet discharging roller <NUM> and switching the sheet discharging flapper in a state where the sheet discharging roller <NUM> retains the document, the ADF <NUM> moves the document toward a reversing path <NUM>. The ADF <NUM> causes the moved document to collide with the registration roller <NUM> from the reversing path <NUM>, and the document is formed into a loop shape again. The skew of the document in the conveyance is thereby corrected. After that, by the conveyance roller <NUM> and the large roller <NUM> moving the document again to the moving document reading glass <NUM>, the ADF <NUM> can read the rear surface of the document by the moving document reading glass <NUM>.

The document installation tray <NUM> is provided with a guide regulation plate <NUM> slidable in a sub scanning direction of the stacked document bundle S, and is also provided with a document width detection sensor (not illustrated) that detects a document width in conjunction with the guide regulation plate <NUM>. By the combination of the above-described document width detection sensor and a pre-registration sensor <NUM>, a document size of the document bundle S stacked on the document installation tray <NUM> becomes detectable. In addition, using a document length detection sensor (not illustrated) provided in a conveyance path, it is possible to detect a document length based on a conveyance distance from a detected leading end to a detected rear end of the document being conveyed. It is also possible to detect a document size by the combination of the detected document length and the above-described document width detection sensor.

By an optical scanner unit <NUM> scanning a document on a platen glass <NUM> in the sub scanning direction indicated by an arrow in <FIG>, the image reading unit <NUM> optically reads image information recorded on the document. In addition, the image reading unit <NUM> controls the ADF <NUM> to convey the documents on the document installation tray <NUM> to a reading position one by one. Furthermore, the image reading unit <NUM> moves the optical scanner unit <NUM> to a reading center position R of the large roller <NUM> of the ADF <NUM>, and reads the document at the reading center position R of the large roller <NUM>. A document on the ADF <NUM> or a document on the platen glass <NUM> is read by the following optical system. The optical system includes the moving document reading glass <NUM>, the platen glass <NUM>, the optical scanner unit <NUM> including a lamp <NUM> and a mirror <NUM>, mirrors <NUM> and <NUM>, a lens <NUM>, and a CCD sensor unit <NUM>. The read image information is photoelectrically converted and the converted image information is input to a controller unit not illustrated in <FIG>, as image data. A white board <NUM> is a white board for creating white level reference data by shading.

In the present exemplary embodiment, the CCD sensor unit <NUM> includes a color image reading (RGB) CCD sensor (three-line sensor unit) <NUM> and a monochrome image reading CCD sensor (single-line sensor unit) <NUM>.

In the present exemplary embodiment, the description has been given of an example in which the image reading unit <NUM> reads a rear surface image of a document by the ADF <NUM> reversing the document. The image reading unit <NUM> may include both of a document front surface reading CCD sensor and a document rear surface reading CCD sensor, and read both surfaces of a document in one document conveyance.

<FIG> is a block diagram illustrating a configuration of the image forming apparatus according to the present exemplary embodiment.

A control block of the ADF <NUM> includes a central processing unit (CPU) <NUM> serving as a control unit, a read-only memory (ROM) <NUM>, a random access memory (RAM) <NUM>, an output port, and an input port. Control programs and fixed parameters are stored in the ROM <NUM>, and input data and work data are stored in the RAM <NUM>.

A motor <NUM> that drives various conveyance rollers, a solenoid <NUM>, and a clutch <NUM> are connected to the output port, and various sensors <NUM> are connected to the input port. For example, the sensors <NUM> include paper jam detection sensors provided at predetermined intervals on a conveyance path, in addition to the document width detection sensor and the document length detection sensor.

The CPU <NUM> controls sheet conveyance in accordance with a control program stored in the ROM <NUM> connected via a bus line. The CPU <NUM> performs serial communication with a CPU <NUM> of the image reading unit <NUM> via a control communication line <NUM>, and exchanges control data with the image reading unit <NUM>. An image leading end signal serving as a reference of a leading end of document image data is also notified to the image reading unit <NUM> via the control communication line <NUM>.

The CPU <NUM> notifies values of the various sensor <NUM> to the image reading unit <NUM> in accordance with control data from the CPU <NUM> of the image reading unit <NUM>.

In a control block of the image reading unit <NUM>, the CPU <NUM> performs all the controls of the image reading unit <NUM>. A ROM <NUM> that stores programs and a RAM <NUM> that provides a work area are connected to the CPU <NUM>. The RAM <NUM> provides a work area including an area for performing nonvolatile storage.

An optical system motor drive unit <NUM> is a driver circuit for driving an optical system drive motor. In the image reading unit <NUM>, the lamp <NUM> and the CCD sensor unit <NUM> (the monochrome image reading CCD sensor <NUM> for front surface images/the color image reading CCD sensor <NUM> for front surface images) are connected the image reading unit <NUM>. The CPU <NUM> executes image reading processing by controlling the optical system motor drive unit <NUM> and controlling the CCD sensor unit <NUM> via an image processing unit <NUM>.

For implementing sheet conveyance, the CPU <NUM> issues an instruction by transmitting a command regarding sheet conveyance control to the CPU <NUM> for sheet conveyance control of the ADF <NUM> via the control communication line <NUM>. Upon receipt of the instruction, the CPU <NUM> implements sheet conveyance by monitoring the sensors <NUM> installed on the conveyance path, and driving the conveyance motor <NUM>, the solenoid <NUM>, and the clutch <NUM> serving as loads. In this manner, the CPU <NUM> causes the ADF <NUM> to perform sheet conveyance and causes the image reading unit <NUM> to perform image reading control. An inter-sheet correction processing unit <NUM> performs inter-sheet correction.

An image signal formed by the lens <NUM> on the CCD sensor unit <NUM> (either the color image reading (RGB) CCD sensor <NUM> or the monochrome image reading CCD sensor <NUM>) is converted into digital image data. Furthermore, various types of image processing for detecting and correcting a streaky image on image data, such as shading, are executed on the converted image data by the image processing unit <NUM>, and the resultant image data is written into an image memory unit <NUM>.

The data written in the image memory unit <NUM> are sequentially transmitted to the controller unit <NUM> via a controller/interface image data information communication line <NUM> including an image transfer clock signal line. Furthermore, an image leading end signal serving as a reference for a leading end of document image data is notified to the controller unit <NUM> via a controller/interface control communication line <NUM> at a timing adjusted by the CPU <NUM>. An image leading end signal notified via a communication line from the ADF <NUM> is similarly notified to the controller unit <NUM> via the controller/interface control communication line <NUM> at a timing adjusted by the CPU <NUM> of the image reading unit <NUM>.

The CPU <NUM> controls the image processing unit <NUM> connected to a control bus line. Furthermore, the CPU <NUM> controls the CCD sensor unit <NUM> by transmitting a control signal from a control communication line <NUM> to the CCD sensor unit <NUM> via the image processing unit <NUM>. While a document image is scanned by the CCD sensor unit <NUM>, the document image is read by the color image reading CCD sensor <NUM> or the monochrome image reading CCD sensor <NUM>. Then, an analog image signal corresponding to read one line is output to a CCD control unit <NUM> from an image data communication line <NUM> or <NUM> including an image transfer clock signal line.

The analog signal is converted into the digital image data by the CCD control unit <NUM> and transmitted to the controller unit <NUM> via the image data information communication line <NUM> by way of the image memory unit <NUM> from an image data information communication line <NUM> including an image transfer clock signal line.

The CPU <NUM> performs serial communication with a CPU <NUM> of the controller unit <NUM> via the image data information communication line <NUM>, and exchanges control data with the controller unit <NUM>. Based on control data from the CPU <NUM> of the controller unit <NUM>, the CPU <NUM> detects a shape abnormality in a document being conveyed. In the shape abnormality detection, for each document, a difference between a distance from the uppermost surface of the document bundle S that has been measured before a conveyance start, and a distance from the uppermost surface of the document bundle S that has been measured after a certain period of time (t2) elapses from the conveyance start is calculated, and if the calculated difference is equal to or larger than a predetermined difference (d1), it is determined that the document has a shape abnormality. Then, the CPU <NUM> notifies the determination result to the CPU <NUM> of the controller unit <NUM>.

The controller unit <NUM> for image processing is a device that controls an entire image forming apparatus <NUM> including the ADF <NUM>, the image reading unit <NUM>, and the image forming unit <NUM>. The controller unit <NUM> includes the CPU <NUM>, an image processing circuit <NUM>, a scanner interface (IF) <NUM>, an image memory <NUM>, an operation unit <NUM>, a RAM <NUM> that provides a work area, a ROM <NUM> that stores programs, a printer IF <NUM>, and a hard disk drive (HDD) <NUM>. The RAM <NUM> provides a work area including an area for performing nonvolatile storage. The ROM <NUM> and the HDD <NUM> are examples of a computer-readable storage medium.

Alternatively, a program may be loaded from the HDD <NUM> onto the RAM <NUM> and executed by the CPU <NUM>.

The image data transmitted to the controller unit <NUM> via the image data information communication line <NUM> is saved into the image memory <NUM> via the scanner IF <NUM>.

The image processing circuit <NUM> converts an image in the image memory <NUM> and returns the converted image to the image memory <NUM>. The image conversion processing performed by the image processing circuit <NUM> includes rotation processing of rotating an image including <NUM> pixels × <NUM> pixels at a designated angle, and resolution conversion processing of converting the resolution of an image. The image conversion processing performed by the image processing circuit <NUM> further includes scaling processing of scaling an image, and color space conversion processing of converting an input multivalued image from a YUV image into a Lab image using matrix calculation and a look-up table (LUT). The color space conversion uses <NUM> × <NUM> matrix calculation and a one-dimensional LUT, and can perform known background removal and show-through reduction.

The controller unit <NUM> includes a network interface (IF) (not illustrated), and performs transmission and reception of image data and other data with an external personal computer (PC).

The image forming unit <NUM> conveys recording paper (sheet), prints image data onto the recording paper as a visible image, and discharges the recording paper to the outside of the apparatus. The image forming unit <NUM> includes a control unit <NUM> that controls the image forming unit <NUM>, the sheet feeding unit <NUM> including a plurality of types of recording paper cassettes, and a marking unit <NUM> having a function of transferring and fixing image data onto the recording paper. The image forming unit <NUM> further includes the sheet discharging unit <NUM> having a function of outputting the printed recording paper to the outside of the apparatus, and the finisher unit <NUM> that performs punching processing and sorting processing.

When the marking unit <NUM> becomes ready to perform image formation, the control unit <NUM> transmits an image leading end signal serving as a reference of a leading end, to the controller unit <NUM> via a controller/interface control communication line <NUM>.

Then, the marking unit <NUM> transfers and fixes image data transmitted via a controller/interface image communication line <NUM>, onto the recording paper.

Hereinafter, the operation unit <NUM> illustrated in <FIG> will be described with reference to <FIG>. A liquid crystal display (LCD) touch panel <NUM> is used for performing main mode settings and status display. A numerical keypad <NUM> receives input of numerical values from <NUM> to <NUM>. An ID key <NUM> is used for inputting a section number and a passcode mode when the apparatus is managed for each section.

A reset key <NUM> is a key for resetting a set mode. A guide key <NUM> is a key for displaying an explanatory screen of each mode. An interrupt key <NUM> is a key for performing interrupt copy.

A start key <NUM> is a key for receiving an execution instruction for copy or scan. A stop key <NUM> is a key for stopping a job being executed (copy job or scan job).

A user mode key <NUM> is a key for transitioning to a user mode screen. On the user mode screen, the image forming apparatus receives various settings regarding the apparatus.

A power saving key <NUM> is a key for shifting the image forming apparatus to a power saving state. If the power saving key <NUM> is selected again when the image forming apparatus is in the power saving state, the image forming apparatus returns from the power saving state.

A counter check key <NUM> is a key for displaying, on the LCD touch panel <NUM>, a count screen displaying the total number of copies that have been used so far.

A light-emitting diode (LED) <NUM> indicates that the apparatus is executing a job or accumulating an image into an image memory. An error LED <NUM> indicates that the apparatus is in an error state such as a jam or door open. A power switch LED <NUM> indicates that a main switch of the apparatus is turned ON.

A copy screen <NUM> illustrated in <FIG> is a screen to be displayed on the LCD touch panel <NUM>. As basic settings, buttons for setting color selection <NUM>, a copy ratio <NUM>, and sheet selection <NUM> are disposed as illustrated in the copy screen <NUM> in <FIG>, and these setting statuses are displayed in a region <NUM>. The settings other than the basic settings can be selected by pressing an other functions button <NUM>. <FIG> illustrates an other functions setting screen <NUM>, and the setting of functions other than the color selection <NUM>, the copy ratio <NUM>, and the sheet selection <NUM> can be performed. A shortcut button of a function frequently-used by the user among these functions can be created on the copy screen. In this example, two-sided <NUM> for setting two-sided printing and show-through reduction <NUM> for setting show-through reduction of a document are disposed as shortcut buttons. Furthermore, finishing <NUM> for setting an output mode to be used in printing or for setting postprocessing is disposed as a shortcut button.

A sheet thickness setting screen <NUM> illustrated in <FIG> is an example of a screen for setting a sheet thickness of a document (thickness of paper). The sheet thickness setting screen <NUM> illustrated in <FIG> is displayed upon the document detection sensor <NUM> detecting a document, for example. Alternatively, the sheet thickness setting screen <NUM> can also be manually displayed by selecting a sheet thickness setting provided as the other functions <NUM>. On the sheet thickness setting screen <NUM>, thick paper <NUM>, plain paper <NUM>, or thin paper <NUM> is selectable. The description has been given of an example of displaying the thick paper <NUM>, the plain paper <NUM>, and the thin paper <NUM> as buttons. Alternatively, the thick paper <NUM>, the plain paper <NUM>, and the thin paper <NUM> may be displayed as a list including each button as one record. Buttons and records are examples of objects. By pressing an OK key <NUM> after selecting a sheet thickness, the user sets the selected sheet thickness. The set sheet thickness is saved into the RAM <NUM>.

The other functions setting screen <NUM> illustrated in <FIG> is a screen for performing setting of advanced functions of a copy function. The other functions setting screen <NUM> is displayed when the other functions button <NUM> on the copy screen <NUM> is selected. The other functions setting screen <NUM> includes the two-sided <NUM>, the show-through reduction <NUM>, the finishing <NUM>, and density <NUM> for setting print density. The other functions setting screen <NUM> also includes number of copy printing <NUM> for setting print designation of a copy number on a print document, and a sheet thickness setting <NUM> for setting a sheet thickness of a document. The number of copy printing <NUM> and the sheet thickness setting <NUM> are both displayed as buttons.

An advanced sheet thickness setting screen <NUM> in <FIG> illustrates an example of a screen for performing a sheet thickness setting. The advanced sheet thickness setting screen <NUM> is displayed when the sheet thickness setting <NUM> is pressed on the other functions setting screen <NUM>. On the advanced sheet thickness setting screen <NUM>, thick paper <NUM>, plain paper <NUM>, or thin paper <NUM> is selectable. By pressing an OK key <NUM> after selecting a sheet thickness, the selected sheet thickness is set. By selecting a cancel key <NUM>, the setting of a sheet thickness can be cancelled. The description has been given of an example of displaying the thick paper <NUM>, the plain paper <NUM>, and the thin paper <NUM> as buttons. Alternatively, the thick paper <NUM>, the plain paper <NUM>, and the thin paper <NUM> may be displayed as a list including each button as one record. Buttons and records are examples of objects. By pressing the OK key <NUM> after selecting a sheet thickness, the user sets the selected sheet thickness. The set sheet thickness is saved into the RAM <NUM>.

<FIG> illustrates an example of a sheet thickness selection method setting screen. The screen can be displayed by an operation performed on the user mode screen. The user mode screen is displayed by the press of the user mode key <NUM> on the operation unit <NUM>. Functions for performing various settings in the image forming apparatus are additionally prepared on the user mode screen although these functions are not illustrated in the drawings.

A sheet thickness selection method setting screen <NUM> includes a fixed setting <NUM> and a designation setting <NUM>, which are buttons for setting a sheet thickness selection method. The designation setting <NUM> is a button for enabling a function of automatically displaying the sheet thickness setting screen <NUM> upon detecting that a document is placed on the document installation tray <NUM>. The fixed setting <NUM> is a button for disabling the function of automatically displaying the sheet thickness setting screen <NUM> upon detecting that a document is placed on the document installation tray <NUM>. By selecting either the fixed setting <NUM> or the designation setting <NUM>, the user can set the selected sheet thickness selection method. When the fixed setting <NUM> is selected, thick paper <NUM>, plain paper <NUM>, and thin paper <NUM> for performing a sheet thickness setting are displayed in a sheet thickness fixed setting region <NUM>. The thick paper <NUM>, the plain paper <NUM>, or the thin paper <NUM> is selectable. If an OK key <NUM> is selected in a state where any one of the thick paper <NUM>, the plain paper <NUM>, and the thin paper <NUM> is selected, the fixed setting selected as a sheet thickness selection method and the selected sheet thickness are set and saved into the RAM <NUM>.

A specific example will be described with reference to <FIG> illustrates an example of a screen to be displayed when the fixed setting is selected as a sheet thickness selection method setting and thick paper is selected as a sheet thickness fixed setting. <FIG> illustrates a state where the fixed setting <NUM> is selected as a sheet thickness setting and the thick paper <NUM> is selected. By pressing the OK key <NUM> in this state, the fixed setting is set in a sheet thickness selection method setting <NUM> in <FIG>, and thick paper is set in a sheet thickness fixed setting <NUM> in <FIG>, which will be described below.

If a cancel key <NUM> is selected, the settings of a sheet thickness selection method and a sheet thickness can be cancelled.

<FIG> illustrates an example of a screen to be displayed when the designation setting <NUM> is selected as a sheet thickness selection method setting. When the designation setting <NUM> is selected as a sheet thickness setting, a setting button is not displayed in a sheet thickness fixed setting region <NUM>. If the OK key <NUM> is pressed in this state, the designation setting is set in the sheet thickness selection method setting <NUM> in <FIG>.

<FIG> is a diagram illustrating an example of a setting value saved in the RAM <NUM>. An apparatus setting is an area for saving setting values used in common in the entire apparatus, and includes the sheet thickness selection method setting <NUM>, the sheet thickness fixed setting <NUM>, and a sheet thickness designation setting <NUM>. An apparatus setting other than these may exist. A copy setting <NUM> is an area for saving setting values used in a copy function. As examples, the copy setting <NUM> includes a sheet thickness setting <NUM>, page printing <NUM>, N-in-one printing <NUM>, bookbinding <NUM>, and the number of copies <NUM>. These setting items are examples, and a copy setting other than these may be saved. In addition, an area for saving setting values of functions other than the copy function such as a data transmission function may be provided.

The image forming apparatus according to the present exemplary embodiment controls the execution of a copy job based on these settings.

First of all, a flowchart for setting a sheet thickness selection method setting from the user mode screen will be described with reference to <FIG>.

The flowchart is started when the user mode key <NUM> of the operation unit <NUM> is selected, the user mode screen is displayed, and a sheet thickness selection method setting is selected from the user mode screen. In addition, the flowchart is performed by the CPU <NUM> of the controller unit <NUM> executing a control program read from the ROM <NUM> and loaded onto the RAM <NUM>.

In step S801, the CPU <NUM> displays the sheet thickness selection method setting screen <NUM> illustrated in <FIG>, on the LCD touch panel <NUM>. Then, the LCD touch panel <NUM> receives, on the sheet thickness selection method setting screen <NUM>, the selection of the fixed setting <NUM> or the designation setting <NUM>, and the selection of the thick paper <NUM>, the plain paper <NUM>, or the thin paper <NUM> displayed in the sheet thickness fixed setting region <NUM>. The CPU <NUM> saves the received settings into the RAM <NUM>.

Next, in step S802, the CPU <NUM> determines whether the selection of the cancel key <NUM> has been received. If the selection of the cancel key <NUM> has been received (YES in step S802), the CPU <NUM> ends this flow without reflecting the selection state on the sheet thickness selection method setting screen <NUM> in the apparatus setting. On the other hand, if the selection of the cancel key <NUM> has not been received (NO in step S802), the CPU <NUM> advances the processing to step S803.

In step S803, the CPU <NUM> determines whether the selection of the OK key <NUM> has been received. If the selection of the OK key <NUM> has been received (YES in step S803), the CPU <NUM> advances the processing to step S804, and if the selection of the OK key <NUM> has not been received (NO in step S803), the CPU <NUM> returns the processing to step S801.

In step S804, the CPU <NUM> determines which setting of the fixed setting <NUM> and the designation setting <NUM> is selected as a sheet thickness selection method setting, and if the fixed setting <NUM> is selected ("FIXED SETTING" in step S804), the CPU <NUM> advances the processing to step S805, and if the designation setting <NUM> is selected ("DESIGNATION SETTING" in step S804), the CPU <NUM> advances the processing to step S806.

In step S805, the CPU <NUM> saves the fixed setting in the sheet thickness selection method setting <NUM> in the apparatus setting. Then, the CPU <NUM> saves a sheet thickness selected from among the thick paper <NUM>, the plain paper <NUM>, and the thin paper <NUM> displayed in the sheet thickness fixed setting region <NUM>, in the sheet thickness fixed setting <NUM>, and ends this flowchart.

In step S806, the CPU <NUM> saves the designation setting in the sheet thickness selection method setting <NUM> in the apparatus setting, and ends this flowchart.

<FIG> illustrates an example of a management structure of screen information for controlling the display of a screen that is saved in the RAM <NUM>, and the management structure has a table structure. Information regarding a screen that can be displayed on the image forming apparatus is stored.

A screen ID <NUM> is uniquely allocated for each type of a screen, and the type of a screen can be uniquely identified based on the screen ID <NUM>. A display priority order <NUM>, a state name <NUM>, and a state bit <NUM> are stored in association with the screen ID <NUM>. An item other than these may be stored, but the description will be omitted. In addition, a screen ID other than the examples of screen IDs illustrated in <FIG> may be stored, but the description will be omitted.

In the table illustrated in <FIG>, the highest display priority order <NUM> is allocated to a screen (shutting down screen) having the screen ID <NUM> of <NUM>.

The state name <NUM> indicates that a shutdown is being executed, and indicates that the shutting down screen is displayed when a shutdown is being executed. The state bit <NUM> indicates <NUM> when the corresponding state currently occurs, and indicates <NUM> when the corresponding state does not occur. In the table illustrated in <FIG>, the state bit <NUM> associated with the screen ID <NUM> of <NUM> indicates OFF. This indicates that the image forming apparatus is not executing a shutdown. Thus, the screen having the screen ID <NUM> of <NUM> is not displayed as a pop-up screen.

On the other hand, a screen (paper jam display screen) having the screen ID <NUM> of <NUM> has the twentieth highest display priority order <NUM>, and the state name <NUM> indicates that the screen is a screen to be displayed when a paper jam has occurred. In the example of the table illustrated in <FIG>, the state bit <NUM> indicates ON. In other words, a paper jam has occurred in the image forming apparatus.

In addition, a screen (sheet thickness setting screen) having the screen ID <NUM> of <NUM> has the seventieth highest display priority order <NUM>, and the state name <NUM> indicates that the screen is a pop-up screen to be displayed if a document is placed when the sheet thickness designation setting is set. In the example of the table illustrated in <FIG>, the state bit <NUM> indicates ON. In other words, the state bit <NUM> indicates a state where a document is placed when the designation setting <NUM> is set.

At this time, the state bit <NUM> of a screen having a screen ID other than the screens having the screen IDs illustrated in <FIG> is set to OFF. In other words, the image forming apparatus is in a state of a paper jam and in a state where a document is installed with the designation setting <NUM> being set. In this case, because the paper jam display screen having the screen ID <NUM> of <NUM> has the higher display priority order <NUM> than that of the sheet thickness setting screen having the screen ID <NUM> of <NUM>, the paper jam display screen is displayed.

<FIG> illustrates an example of an error screen displaying a status of a paper jam. In the example illustrated in <FIG>, information for promoting the user to clear the paper jam is displayed. An apparatus picture <NUM> displaying the position of the paper jam, and a message <NUM> for prompting the user to perform processing for the paper jam are displayed. While viewing the screen, the user checks the position where the paper jam has occurred, and removes a sheet remaining in the apparatus without being conveyed. In addition, a next button may be provided on the screen illustrated in <FIG>, and if the next button is selected, a plurality of procedures necessary for clearing the paper jam may be displayed in order. By following the procedures, the user can remove the paper jam.

Next, with reference to the flowchart illustrated in <FIG>, the description will be given of the details of processing performed depending on a sheet thickness selection method in an apparatus setting when a document is placed on the ADF <NUM> and scan is executed according to the present exemplary embodiment.

This flowchart is started from a state where the copy screen <NUM> is displayed on the LCD touch panel <NUM>. The series of processes is performed by the CPU <NUM> of the controller unit <NUM> executing a control program read from the ROM <NUM> and loaded onto the RAM <NUM>.

In step S901, the CPU <NUM> determines whether a detection state of the document detection sensor <NUM> of the ADF <NUM> has changed, and if the CPU <NUM> determines that the detection state of a document has changed to "present" from "absent" (YES in step S901), the CPU <NUM> advances the processing to step S902, and if a document is not detected (NO in step S901), the CPU <NUM> ends the processing in the flowchart illustrated in <FIG>.

In step S902, the CPU <NUM> determines whether a designation setting is saved in the sheet thickness selection method setting <NUM> saved in the RAM <NUM>. If a designation setting is saved (YES in step S902), the CPU <NUM> advances the processing to step S903, and if a designation setting is not saved (NO in step S902), the CPU <NUM> ends the processing in the flowchart illustrated in <FIG>.

In step S903, the CPU <NUM> determines whether an error screen displaying a status of a paper jam is currently displayed, based on whether the state bit <NUM> associated with the screen having the screen ID <NUM> of <NUM> in <FIG> indicates ON. If the CPU <NUM> determines that an error screen displaying a status of a paper jam is displayed (YES in step S903), the CPU <NUM> advances the processing to step S904, and if the CPU <NUM> determines that an error screen displaying a status of a paper jam is not displayed (NO in step S903), the CPU <NUM> advances the processing to step S905.

In step S904, the CPU <NUM> determines whether the paper jam has been cleared, based on whether the state bit <NUM> associated with the screen having the screen ID <NUM> of <NUM> in <FIG> indicates OFF. If the CPU <NUM> determines in step S904 that the paper jam has been cleared (YES in step S904), the CPU <NUM> returns the processing to step S901. If the CPU <NUM> determines in step S904 that the paper jam has not been cleared (NO in step S904), the CPU <NUM> repeats the processing in step S904 and waits until the paper jam is cleared.

In step S905, the CPU <NUM> displays, on the LCD touch panel <NUM>, with the sheet thickness setting screen <NUM> illustrated in <FIG> being superimposed onto the current screen, and receives the selection of a sheet thickness setting.

In step S906, the CPU <NUM> determines whether the selection of the OK key <NUM> has been received, and if the selection of the OK key <NUM> has been received (YES in step S906), the CPU <NUM> advances the processing to step S907. If the selection of the OK key <NUM> has not been received (NO in step S906), the CPU <NUM> returns the processing to step S905. In step S905, the CPU <NUM> displays the sheet thickness setting screen <NUM> on the LCD touch panel <NUM>.

In step S907, the CPU <NUM> saves information regarding a sheet thickness selected at the time (thick paper/plain paper/thin paper), in the sheet thickness designation setting <NUM> in the apparatus setting in the RAM <NUM>, and ends the processing in the flowchart illustrated in <FIG>.

Next, with reference to a flowchart illustrated in <FIG>, the description will be given of the details of processing performed when a copy job is executed according to the present exemplary embodiment.

The description will be given using copy as an example of a function of performing scan. Nevertheless, the processing may be applied to other functions such as an e-mail transmission function of transmitting, by e-mail, image data representing an image of a scanned document, or a facsimile transmission function of transmitting, by Group <NUM> Facsimile (G3FAX), image data representing an image of a scanned document.

The series of processes is performed by the CPU <NUM> of the controller unit <NUM> executing a control program read from the ROM <NUM> and loaded onto the RAM <NUM>.

In step S1001, the CPU <NUM> determines whether the selection of the start key <NUM> of the operation unit <NUM> has been received. If the CPU <NUM> determines that the selection of the start key <NUM> has been received (YES in step S1001), the CPU <NUM> advances the processing to step S1002, and if the CPU <NUM> determines that the selection of the start key <NUM> has not been received (NO in step S1001), the CPU <NUM> repeats the processing in step S1001.

In step S1002, the CPU <NUM> determines a value in the sheet thickness setting <NUM> in the copy setting <NUM>. If the CPU <NUM> determines that a sheet thickness is set (YES in step S1002), the CPU <NUM> advances the processing to step S1006. On the other hand, if the CPU <NUM> determines that a sheet thickness is not set (NO in step S1002), the CPU <NUM> advances the processing to step S1003.

In step S1003, the CPU <NUM> displays, on the LCD touch panel <NUM>, the sheet thickness setting screen <NUM> illustrated in <FIG> being superimposed onto the current screen, and receives the selection of a sheet thickness setting.

Next, in step S1004, the CPU <NUM> determines whether the selection of the OK key <NUM> has been received, and if the selection of the OK key <NUM> has been received (YES in step S1004), the CPU <NUM> advances the processing to step S1005. If the selection of the OK key <NUM> has not been received (NO in step S1004), the CPU <NUM> returns the processing to step S1003.

In step S1005, the CPU <NUM> saves information regarding a sheet thickness selected at the time (thick paper/plain paper/thin paper), in the sheet thickness designation setting <NUM> in the apparatus setting in the RAM <NUM>, and advances the processing to step S1006.

In step S1006, the CPU <NUM> determines a value in the sheet thickness setting <NUM> in the copy setting <NUM>. If the sheet thickness determined in step S1006 is plain paper (predetermined thickness) ("PLAIN PAPER" in step S1006), the CPU <NUM> advances the processing to step S1008. If the sheet thickness determined in step S1006 is thick paper (thickness larger than the predetermined thickness) ("THICK PAPER" in step S1006), or if the determined sheet thickness is thin paper (thickness smaller than the predetermined thickness) ("THIN PAPER" in step S1006), the CPU <NUM> advances the processing to step S1007. In step S1007, the CPU <NUM> notifies the CPU <NUM> of the ADF <NUM> that a document conveyance speed is to be set to a low speed.

If the CPU <NUM> is notified that a document conveyance speed is to be set to a low speed, the CPU <NUM> decreases rotating speeds of motors that respectively drive the conveyance roller <NUM>, the registration roller <NUM>, the conveyance roller <NUM>, the conveyance roller <NUM>, the large roller <NUM>, and the sheet discharging roller <NUM>, and controls a conveyance speed to be lower than a normal conveyance speed. For example, the CPU <NUM> controls a conveyance speed to be half of the normal conveyance speed. As a result, when a document is thick paper, it is possible to overcome the shortage in torque at a curved portion of a conveyance path, and prevent the thick paper document from getting jammed at the curved portion of the conveyance path. Meanwhile, when a document is thin paper, after a discharged thin paper document completely falls, a next document is discharged. With this configuration, it is possible to enhance a stacking property of the sheet discharging unit, and prevent the thin paper document from getting jammed near the sheet discharging unit.

In step S1008, the CPU <NUM> transmits a sheet feeding start instruction to the CPU <NUM>. Upon receiving the sheet feeding start instruction from the CPU <NUM>, the CPU <NUM> drives the motor <NUM> and starts to feed the document. If a notification indicating that a document conveyance speed is to be set to a low speed is not received, the CPU <NUM> controls the document to be conveyed at the normal conveyance speed. On the other hand, if a notification indicating that a document conveyance speed is to be set to a low speed is received, the CPU <NUM> controls the document to be conveyed at half conveyance speed of the normal conveyance speed.

In step S <NUM>, the CPU <NUM> determines whether a paper jam has occurred, based on a signal from the ADF <NUM>. If the CPU <NUM> determines that a paper jam has occurred (YES in step S1009), the CPU <NUM> advances the processing to step S1010. On the other hand, if the CPU <NUM> determines that a paper jam has not occurred (NO in step S1009), the CPU <NUM> advances the processing to step S1016.

In step S1010, the CPU <NUM> stores information indicating a paper jam occurrence state, into the RAM <NUM>. Specifically, the CPU <NUM> changes the state bit <NUM> associated with the screen having the screen ID <NUM> of <NUM> to ON. After that, the CPU <NUM> advances the processing to step S1011.

In step S1011, the CPU <NUM> displays, on the LCD touch panel <NUM>, the paper jam display screen illustrated in <FIG> being superimposed on the current screen, and advances the processing to step S1012.

In step S1012, the CPU <NUM> determines whether the paper jam has been cleared. More specifically, the CPU <NUM> determines whether any unremoved sheet remains on the conveyance path of the document, based on signals from the sensors <NUM>. Then, if no unremoved sheet remains, the CPU <NUM> determines that the paper jam has been cleared (YES in step S1012), and advances the processing to step S1013. On the other hand, if any unremoved sheet remains, the CPU <NUM> determines that the paper jam has not been cleared (NO in step S1012), and repeats the processing in step S1012.

In step S1013, the CPU <NUM> stores information indicating a paper jam cleared state, into the RAM <NUM>. Specifically, the CPU <NUM> changes the state bit <NUM> associated with the screen having the screen ID <NUM> of <NUM> to OFF. After that, the CPU <NUM> advances the processing to step S1014.

In step S1014, the CPU <NUM> controls display so as to close the paper jam display screen in <FIG> that is displayed on the LCD touch panel <NUM>, and advances the processing to step S1015.

In step S1015, the CPU <NUM> determines whether a scan restart instruction for restarting scan has been received. If the CPU <NUM> determines that a scan restart instruction has been received (YES in step S1015), the CPU <NUM> returns the processing to step S1008, and if the CPU <NUM> determines that a scan restart instruction has not been received (NO in step S1015), the CPU <NUM> repeats the processing in step S1015.

In step S1016, the image reading unit <NUM> reads an image on the document and generates image data.

The generated image data is transmitted to the controller unit <NUM> via the image data information communication line <NUM> and saved into the image memory <NUM> via the scanner IF <NUM>.

In step S1017, the CPU <NUM> executes image processing on the image data saved in the image memory <NUM>.

In step S1018, the CPU <NUM> determines whether a document is present on the document installation tray <NUM>, and if the CPU <NUM> determines that a document is present (YES in step S1018), the processing returns to step S1008, and if the CPU <NUM> determines that a document is absent (NO in step S1018), the processing proceeds to step S1019.

In step S1019, the CPU <NUM> transmits the image data and a printing instruction to the image forming unit <NUM>, and causes the image forming unit <NUM> to execute printing. In the case of executing e-mail transmission or facsimile transmission, in step S1019, the CPU <NUM> is only required to perform processing of transmitting the data to a destination designated by the user, instead of transmitting a printing instruction.

In the present exemplary embodiment, a sheet thickness setting screen is displayed upon detecting that a document is placed in a state where an error screen displaying a status of a paper jam is not displayed, and when a document is placed in a state where an error screen displaying a status of a paper jam is displayed, a sheet thickness setting screen is not displayed.

According to the present exemplary embodiment as described above, while a thickness setting screen is displayed upon detecting that a document is placed on a document tray, a specific screen desired to be continuously displayed can be prevented from being hidden upon detecting that a document is placed on a document tray. Thus, when a paper jam has occurred, by preferentially displaying a screen for clearing the paper jam, it is possible to avoid impairing user-friendliness.

In addition, if a paper jam occurs during job execution, after the paper jam is cleared, by restarting the job with successively using the thickness setting saved in step S1005, without displaying a sheet thickness setting screen, it becomes possible to save the user's trouble of performing a sheet thickness setting again on the sheet thickness setting screen.

In the above-described exemplary embodiment, the description has been given using a paper jam display screen as an example of a specific screen, but the specific screen is not limited to this. For example, the specific screen may be a screen such as the user mode screen to be displayed by the press of the user mode key <NUM>. With this configuration, it is possible to prevent an apparatus setting from being disturbed by the user mode screen switching to a sheet thickness setting screen upon detecting that a document is placed when the apparatus setting of an image forming apparatus is being performed on the user mode screen.

Claim 1:
An image reading apparatus that conveys a document placed on a document tray (<NUM>), based on information indicating a thickness of the document, the image reading apparatus comprising:
detection means (<NUM>) configured to detect that a document is placed on the document tray (<NUM>);
display means (<NUM>) configured to display a setting screen for setting a thickness of the document, based on the detection means (<NUM>) detecting that the document is placed on the document tray (<NUM>);
conveyance control means (<NUM>) configured to control, based on information indicating a thickness of a document that is set on the setting screen displayed by the display means (<NUM>), conveyance means (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) to convey the document; and
reading means (<NUM>) configured to read an image on a document conveyed by the conveyance means (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>),
characterized in that:
the display means (<NUM>) is configured to display, based on the detection means (<NUM>) detecting that the document is placed on the document tray (<NUM>) in a state where a first predetermined screen is being displayed by the display means (<NUM>), the setting screen so that at least a part of the first predetermined screen is hidden by the setting screen, and
the display means (<NUM>) is configured to not display the setting screen based on the detection means (<NUM>) detecting that the document is placed on the document tray (<NUM>) in a state where a second predetermined screen, different from the first predetermined screen, is being displayed by the display means (<NUM>).