BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart of an exemplary process performed by an engine control unit according to a first exemplary embodiment of the present invention.
FIG. 2 is a flow chart of an exemplary process performed by a controller according to the first exemplary embodiment of the present invention.
FIG. 3 is a timing diagram in a normal case of conveying a transfer medium according to the first exemplary embodiment of the present invention.
FIG. 4 is a timing diagram for the case when the size of the transfer medium is large according to the first exemplary embodiment of the present invention.
FIG. 5 illustrates an exemplary data structure of a command sent from a controller when feeding of the transfer medium is started according to a second exemplary embodiment of the present invention.
FIG. 6 illustrates an exemplary data structure of status information sent from an engine control unit when the engine control unit detects the size of the transfer medium according to the second exemplary embodiment of the present invention.
FIG. 7 illustrates an exemplary data structure of status information sent from the engine control unit when a transfer-medium size mismatch occurs according to the second exemplary embodiment of the present invention.
FIG. 8 illustrates an exemplary data structure of status information sent from the engine control unit when a transfer-medium size mismatch occurs according to the second exemplary embodiment of the present invention.
FIG. 9 illustrates the detailed data structure of the status information sent from the engine control unit when the engine control unit detects the size of a transfer medium according to the second exemplary embodiment of the present invention.
FIG. 10 illustrates the detailed data structure of status information sent from the engine control unit when a transfer-medium size mismatch occurs according to the second exemplary embodiment of the present invention.
FIG. 11 is a flow chart of a process performed by the engine control unit according to the second exemplary embodiment of the present invention.
FIG. 12 is a process flow diagram according to the second exemplary embodiment of the present invention.
FIG. 13 is a flow chart of a process performed by an engine control unit according to a third exemplary embodiment of the present invention.
FIG. 14 is a flow chart of a process performed by an engine control unit according to the third exemplary embodiment of the present invention.
FIG. 15 is a cross-sectional view of an exemplary structure of an existing image forming apparatus in the form of a laser printer.
FIG. 16 illustrates signals exchanged between a known engine control unit and a controller.
FIG. 17 is a timing diagram illustrating signals exchanged between the known engine control unit and the controller for synchronizing images.
FIGS. 18A-C illustrate the operation of a registration sensor.
FIG. 19 illustrates a process performed by a known engine control unit.
FIG. 20 illustrates a process performed by a known engine control unit.
FIG. 21 illustrates a process performed by a known engine control unit.
FIG. 22 illustrates a process performed by a known controller.
FIG. 23 is a timing diagram for the case of a known normal conveying operation.
FIG. 24 is a timing diagram for the known case of conveyance of a long transfer medium.
FIG. 25 is a cross-sectional view of a known image forming apparatus in the form of a laser printer on which a paper output option unit is installed.
FIG. 26 is a block diagram illustrating a relationship among an engine control unit, a controller, and the paper output option control unit of the known image forming apparatus.
DESCRIPTION OF THE EMBODIMENTS
Exemplary embodiments, features and aspects of the present invention are described in detail with reference to the accompanying drawings. The same numbering will be used in describing similar components in the following drawings.
An image forming apparatus and units according to the exemplary embodiments of the present invention are described next with reference to the accompanying drawings. The image forming apparatus according to the exemplary embodiments has a configuration similar to that illustrated in FIGS. 15 to 26. Therefore, only configurations different from those illustrated in FIGS. 15 to 26 are described below. A transfer medium used in the following embodiments is a recording medium on which an image is to be formed. For example, a recording sheet, such as a plain paper sheet, a thick paper sheet, a glossy paper sheet, or an over head transparency (OHT) sheet, is used.
First Exemplary Embodiment
According to a first exemplary embodiment of the present invention, when a transfer-medium size mismatch occurs, information indicating the transfer-medium size mismatch is sent to a controller and a paper output option unit at the earliest moment so that the conveyance control of the transfer medium including switching of a paper output port is optimized.
Since the configuration of an image forming apparatus according to the present embodiment is similar to that of the above-described known image forming apparatus shown in FIG. 25, description is not repeated. In addition, similar numbering is used in describing the image forming apparatus according to the present embodiment. Furthermore, a sensor 19 and an engine control unit 201 function as a size detecting unit for detecting the size of a transfer medium.
FIG. 1 is a flow chart of a process of detecting the size of a transfer medium performed by an engine control unit 201. This process is performed by a central processing unit (CPU) (not shown) of the engine control unit 201. The CPU reads out a control program from a read only memory (ROM) (not shown) and executes the control program. A difference from the known image forming apparatus is that if the size of a transfer medium exceeds a predetermined value during detection of the size of the transfer medium, the engine control unit 201 sends information indicating the transfer-medium size mismatch (hereinafter referred to as “transfer-medium mismatch information”) to the controller 202 before the process of detecting the size of the transfer medium is completed. Subsequently, the engine control unit 201 sends transfer-medium mismatch information at the time of determining the size of the transfer medium to a paper output option control unit 214 even when the size of the transfer medium is less than the predetermined value via the controller 202. Furthermore, the engine control unit 201 sends a message indicating the size of the transfer medium to the paper output option control unit 214 when the trailing edge of the transfer medium has passed the sensor 19. As used herein, the term “predetermined size” refers to the size of a sheet that is conveyable by the paper output option unit 30.
The first exemplary embodiment is described in more detail with reference to FIG. 1. The engine control unit 201 determines the time to resume conveyance of a transfer medium 2 (step S101). When the time to resume the conveyance of a transfer medium 2 is reached, the engine control unit 201 starts a timer count (step S102). The transfer medium 2 is then conveyed. When the sensor 19 detects the passage of the trailing edge of the transfer medium 2 (step S105) (see FIG. 18C), the engine control unit 201 stops the timer count. The engine control unit 201 computes the size of the transfer medium 2 on the basis of a curved value when the transfer medium 2 is temporarily stopped by a roller 28, a distance between the sensor 19 and the roller 28, and a timer count value (step S106). If the sensor 19 cannot detect the trailing edge of the transfer medium 2 even when a time period corresponding to a maximum size of a transfer medium that is conveyable by the paper output option unit 30 has elapsed (step S103), the engine control unit 201 sends transfer-medium mismatch information to the controller 202 (step S104). Subsequently, the engine control unit 201 determines whether the computed size of the transfer medium 2 is significantly less than a minimum size that is conveyable by the paper output option unit 30 (step S107). If a difference between the computed size of the transfer medium 2 and the minimum size that is conveyable by the paper output option unit 30 is within a predetermined range, the engine control unit 201 completes the transfer-medium size detection sequence. However, if the computed size of the transfer medium 2 is less than the minimum size that is conveyable by the paper output option unit 30 (step S107), the processing of the engine control unit 201 proceeds to step S108. The engine control unit 201 sends transfer-medium size mismatch information to the controller 202 (step S108). Thus, the controller 202 determines that a print failure of the transfer medium 2 occurred. The operations of the image forming apparatus and the paper output option unit 30 are stopped (step S110). Thereafter, the engine control unit 201 detects the trailing edge of the transfer medium 2 and sends a message indicating the size of the transfer medium 2 to the controller 202 (step S109).
FIG. 2 is a flow chart illustrating a process performed by the controller 202 according to the first exemplary embodiment. To carry out this process, a CPU (not shown) of the controller 202 reads out a control program from a ROM (not shown) and executes the control program.
As shown in FIG. 2, the controller 202 receives, from the paper output option control unit 214, the size data of a transfer medium that is conveyable from an FU1 paper output port 24 and the size data of a transfer medium that is conveyable from an FU2 paper output port 31 (step S1101). The controller 202 sends the received size data of the conveyable transfer media to the engine control unit 201. The engine control unit 201 determines whether a transfer-medium size mismatch occurs on the basis of the received size data. If the engine control unit 201 determines that a transfer-medium size mismatch occurs, the controller 202 receives transfer-medium size mismatch information (step S1102-1). If, however, the engine control unit 201 determines that a transfer-medium size mismatch does not occur, the controller 202 receives no information. Subsequently, the controller 202 receives the size data of the transfer medium 2 from the engine control unit 201 (step S1102-2).
The controller 202 determines whether it has received transfer-medium size mismatch information from the engine control unit 201 (step S1103). If not, the controller 202 determines whether the size of the transfer medium 2 is conveyable from the paper output port specified by a user. Subsequently, the controller 202 compares the size of the transfer medium 2 detected by the engine control unit 201 with the conveyable size of a transfer medium sent from a paper output option control unit 214. In this way, the controller 202 determines whether the transfer medium 2 can be output to the paper output port specified by the user (step S1104). If the size of the transfer medium 2 detected by the engine control unit 201 is within the range of the size of a transfer medium conveyable to the specified paper output port, the controller 202 sends the size data of the transfer medium to the paper output option control unit 214 (step S1105) and outputs the transfer medium 2 to the specified paper output port. In this case, the controller 202 directly outputs the transfer medium 2 to the specified paper output port (step S1106).
However, the controller 202 determines that it has received the transfer-medium size mismatch information, the controller 202 determines whether the size of the transfer medium 2 is conveyable to another paper output port of the paper output option unit 30 (step S1107). If a conveyable paper output port is found, the controller 202 submits a paper output port change command to the paper output option control unit 214 (step S1108). Subsequently, the controller 202 outputs the size data of the transfer medium to the paper output option control unit 214 (step 1109) and sends a warning message to the user (step S1110). This warning message indicates that the transfer medium 2 cannot be output to the specified paper output port and the transfer medium 2 is output to another paper output port. If the size of the transfer medium 2 is such that the transfer medium 2 is unconveyable to any other paper output ports, the controller 202 sends information conveying that fact to the engine control unit 201 and the paper output option unit 30 (step S1111) and stops the print operation. Thereafter, the controller 202 sends a message indicating that a print failure occurred, a paper jam occurred, and a paper sheet is left inside the image forming apparatus to the user (step S1112).
FIGS. 3 and 4 are timing diagram for detecting a transfer medium. FIG. 3 is a timing diagram for the case when the size of the transfer medium is small. In many cases, the process is performed in accordance with this timing diagram. FIG. 4 is a timing diagram for the case when the size of the transfer medium is very large. As used herein, the term “very large size of a transfer medium” refers to a size much larger than the size of a transfer medium that is conveyable by the paper output option unit 30 (e.g., an A3 size). Feature of the present embodiment is the operation of sending the transfer-medium mismatch information. The operation of sending is executed before completion of size detection operation of the transfer medium, that is, the operation of sending is executed before detecting the trailing edge of transfer medium. In addition, the term “size of a transfer medium” refers to the length of a transfer medium in a direction in which the transfer medium is conveyed for forming an image. Furthermore, in the present embodiment, only transfer-medium mismatch information that indicates a transfer medium size mismatch is sent. However, the controller 202 may send the transfer-medium mismatch information together with an identification number (hereinafter also referred to as a “transfer medium number”) assigned to each of sheets of a transfer medium in advance. By sending transfer-medium mismatch information together with a transfer medium number, it is clearly determined which transfer medium causes a mismatch. Thus, the controller 202 and the paper output option control unit 214 can perform control more appropriately.
As noted above, in the image forming apparatus to which a paper output option unit can be connected, when the specified size is different from the detected size of a transfer medium, the engine control unit 201 sends transfer-medium size mismatch information to the controller 202 before the size detecting operation performed by the engine control unit 201 is completed. Upon completion of the size detecting operation, the engine control unit 201 sends the detected size data to the controller 202.
In this way, the controller 202 can detect the transfer-medium size mismatch earlier than in known methods. Upon detecting a transfer-medium size mismatch, the controller 202 can select a paper output port capable of outputting the transfer medium, and therefore, the transfer medium can be successfully output. In addition, if the transfer medium cannot be output, the controller 202 can stop the conveyance of the transfer medium at a position at which a user can easily remove the transfer medium (a jam clearance). Thus, ease of use of the image forming apparatus can be improved.
Furthermore, the controller 202 can send the detected size data of a transfer medium to the paper output option unit 30. Thus, the paper output option unit 30 can appropriately set a conveyance speed, a conveyance timing, and a jam determination timing in accordance with the received size data of the transfer medium 2. Consequently, delivery control in the paper output option unit 30 can be facilitated.
Second Exemplary Embodiment
According to a second exemplary embodiment of the present invention, a measured size of a transfer medium is sent to a controller 202 and a paper output option unit 30 together with a transfer medium number assigned to the conveyed transfer medium. The transfer medium number is similar to the one described in Japanese Patent Laid-Open No. 2003-40468. By using the transfer medium number, a correspondence between the size of a transfer medium and the transfer medium is clearly defined. Thus, the processes of the controller 202 and the paper output option control unit 214 can be optimized and simplified.
Since the configuration of an image forming apparatus according to the second exemplary embodiment is similar to that of the above-described known image forming apparatus shown in FIG. 25, description is not repeated. In addition, similar numbering is used in describing the image forming apparatus according to the present embodiment. Furthermore, a sensor 19 and an engine control unit 201 function as a size detecting unit for detecting the size of a transfer medium.
A transfer medium number used in a known image forming apparatus is described first. Subsequently, the present embodiment is described in detail.
FIG. 5 illustrates an exemplary data structure of a four-byte command that is sent from the controller 202 to the engine control unit 201 and the paper output option control unit 214. This command is used for setting transfer medium information.
As shown in FIG. 5, the first byte represents a command code. This command code indicates setting of transfer medium information. The second byte represents a transfer medium number. The controller 202 can set any number in this byte field. However, the maximum number of the transfer medium number is determined to be 255. If a transfer medium number greater than the maximum number is needed, the transfer medium number assigned to the previous transfer medium is re-assigned to a new transfer medium when the previous transfer medium is output and its transfer medium number is released in a sequential manner.
The most significant three bits of the third byte represent a feeder unit number. A feeder unit number is assigned to each of feeder units by the controller 202. The feeder unit number depends on the number of feeder units connected to the image forming apparatus. In the present embodiment, a number between 1 and 7 can be used as the feeder unit number. The least significant five bits of the third byte represent a paper output unit number. A paper output unit number is assigned to each of paper output units by the controller 202. The paper output unit number depends on the number of paper output units connected to the image forming apparatus. In the present embodiment, a number between 1 and 63 can be used as the feeder unit number.
The fourth byte represents a code corresponding to the size of a transfer medium. Information about the size of a transfer medium received from a host computer (not shown) is converted to a code corresponding to information used for the image forming apparatus.
The controller 202 generates paper feed information and paper output information shown in FIG. 5 from print control information received from the host computer. Subsequently, the controller 202 sends the generated information to the engine control unit 201 and the paper output option control unit 214 together with the feeder unit number, the paper output unit number, and the transfer medium number. According to the present embodiment, upon detecting the size of a transfer medium, the engine control unit 201 sends the transfer medium number and information about the size of the transfer medium to the controller 202 at the same time. The controller 202 sends the information about the size of the transfer medium received from the engine control unit 201 to the paper output option control unit 214.
FIG. 6 illustrates an exemplary data structure of two-byte status information about the size of a transfer medium sent from the engine control unit 201 to the controller 202. This status information is sent in response to a command requesting the status information about the size of a transfer medium and sent from the controller 202.
FIG. 9 illustrates the detailed structure of the status information about the size of a transfer medium. The first byte represents the transfer medium number. A transfer medium number received from the controller 202 is set in this field when a transfer medium 2 is fed. The second byte represents a detected size of the transfer medium 2. One binary number in the second byte corresponds to 2 mm.
FIG. 7 illustrates the data structure of two-byte information indicating print failure sent from the engine control unit 201 to the controller 202. This status information is sent to the controller 202 in response to a command requesting the status information about print failure and sent from the controller 202. FIG. 10 illustrates the details of the status information indicating a print failure. The second byte includes information about the transfer medium detected by the engine control unit 201 representing the transfer-medium type mismatch and the transfer-medium size mismatch information (i.e., information indicating that the transfer medium 2 is too long or too short).
As shown in FIG. 8, information indicating the occurrence of print failure may be sent together with the size of a transfer medium and the transfer medium number at one time.
FIG. 11 is a flow chart of a process performed by the engine control unit 201 according to the present embodiment. This process is performed by a central processing unit (CPU) (not shown) of the engine control unit 201 reading out a control program from a ROM (not shown).
The process is described in detail below with reference to FIG. 11. When the transfer medium 2 is fed, the engine control unit 201 receives a transfer medium number corresponding to the transfer medium 2 from the controller 202 (step S201) and starts feeding the transfer medium 2 (step S202). Subsequently, the engine control unit 201 determines the time to resume conveyance of the transfer medium 2 (step S203). When the time to resume the conveyance of a transfer medium 2 is reached, the engine control unit 201 starts a timer count (step S204). The transfer medium 2 is then conveyed. When the sensor 19 detects the passage of the trailing edge of the transfer medium 2 (step S207) (see FIG. 18C), the engine control unit 201 stops the timer count (step S208). The engine control unit 201 computes the size of the conveyed transfer medium 2 on the basis of a curved value when the transfer medium 2 is temporarily stopped by a roller 28, a distance between the sensor 19 and the roller 28, and a timer count value (step S208). If the sensor 19 cannot detect the trailing edge of the transfer medium 2 even when a time corresponding to a maximum size of a transfer medium that is conveyable by the paper output option unit 30 has elapsed (step S205), the engine control unit 201 sends transfer-medium mismatch information to the controller 202 (step S206). Subsequently, the engine control unit 201 determines whether the computed size of the transfer medium 2 is significantly less than a minimum size of a transfer medium that is conveyable by the paper output option unit 30 (step S209). If a difference between the computed size of the transfer medium 2 and the minimum size of a transfer medium that is conveyable by the paper output option unit 30 is within a predetermined range, the engine control unit 201 completes the transfer-medium size detection sequence. However, if the computed size of the transfer medium 2 is significantly less than the minimum size of a transfer medium that is conveyable by the paper output option unit 30, the processing of the engine control unit 201 proceeds to step S210. The engine control unit 201 sends transfer-medium size mismatch information to the controller 202 (step S209). At that time, the controller 202 determines that a print failure of the transfer medium 2 occurred. The operations of the image forming apparatus and the paper output option unit 30 are stopped (step S213). Thereafter, the engine control unit 201 sends the size of the transfer medium 2 and the transfer medium number to the controller 202 (step S211). The controller 202 sends the size of the transfer medium 2 and the transfer medium number to the paper output option unit 30 (step S212).
In this way, the paper output option unit 30 can appropriately set a conveyance speed, a conveyance timing, and a jam determination timing in accordance with the received size data of the transfer medium 2 and the transfer medium number. That is, since the paper output option unit 30 can associate the conveyed transfer medium 2 with the size information about the transfer medium 2, the paper output option unit 30 can set a jam determination timing for the transfer medium 2 in accordance with a conveyance speed, a conveyance timing, and the size of the transfer medium 2.
FIG. 12 is a process flow diagram according to the present embodiment. At step I, the controller 202 sends the transfer medium number, the feeder unit number, and the paper output unit number to the engine control unit 201 and the paper output option control unit 214. At step II, the controller 202 sends a print start instruction to the engine control unit 201 and the paper output option control unit 214. At step III, the controller 202 inquires about the size of the transfer medium 2 to the engine control unit 201. The engine control unit 201 detects the size of the transfer medium 2 to determine whether the detected size matches the size (length) of the transfer medium 2 informed by the controller 202. At step IV, if the detected size does not match the size of the transfer medium 2 informed by the controller 202, the engine control unit 201 sends transfer-medium mismatch information to the controller 202. Subsequently, the engine control unit 201 sends the transfer medium number and the size (length) of the transfer medium 2 to the controller 202. Finally, at step V, the controller 202 sends the transfer medium number and the size (length) of the transfer medium 2 to the paper output option control unit 214.
In the present embodiment, the term “size (length) of a transfer medium” refers to the length of a transfer medium in a direction in which the transfer medium is conveyed for forming an image.
Third Exemplary Embodiment
According to a third exemplary embodiment of the present invention, a measured size of a transfer medium is sent to a controller 202 and a paper output option unit 30 together with a transfer medium number only when the transfer medium is output to a paper output option unit 30. Thus, the internal process of a paper output option control unit 214 can be optimized and simplified.
Since the configuration of an image forming apparatus according to the third exemplary embodiment is similar to that of the above-described known image forming apparatus shown in FIG. 25, description is not repeated. In addition, similar numbering is used in describing the image forming apparatus according to the present embodiment. Furthermore, as in the known image forming apparatus, a sensor 19 and an engine control unit 201 function as a size detecting unit for detecting the size of a transfer medium.
FIG. 13 is a flow chart of an example process performed by the engine control unit 201 according to the present embodiment. To carry out this process, a CPU (not shown) of the engine control unit 201 reads out a control program from a ROM (not shown) and executes the control program.
The process is described in detail next with reference to FIG. 13. When the transfer medium 2 is fed, the engine control unit 201 receives a transfer medium number corresponding to the transfer medium 2 from the controller 202 (step S301) and starts feeding the transfer medium 2 (step S302). Subsequently, the engine control unit 201 determines the time to resume conveyance of the transfer medium 2 (step S303). When the time to resume the conveyance of a transfer medium 2 is reached, the engine control unit 201 determines whether the paper output port for the transfer medium 2 is a duplex printing port (step S304). If the paper output port for the transfer medium 2 is a duplex printing port, the engine control unit 201 does not detect the size of the transfer medium 2 and completes the processing. In the case of duplex printing, the size of the transfer medium 2 has already been detected before an image is formed on a first surface of the transfer medium 2. Accordingly, a size detecting operation is not needed. When outputting the transfer medium 2 to the paper output option unit 30, the engine control unit 201 starts a timer count (step S305). The transfer medium 2 is then conveyed. When the sensor 19 detects the passage of the trailing edge of the transfer medium 2 (step S308) (see FIG. 18C), the engine control unit 201 stops the timer count (step S309). Subsequently, the engine control unit 201 computes the size of the conveyed transfer medium 2 on the basis of a curved value when the transfer medium 2 is temporarily stopped by a roller 28, a distance between the sensor 19 and the roller 28, and a timer count value (step S309). If the sensor 19 cannot detect the trailing edge of the transfer medium 2 even when a time period corresponding to a maximum size of a transfer medium that is conveyable by the paper output option unit 30 has elapsed (step S306), the engine control unit 201 sends transfer-medium mismatch information to the controller 202 (step S307). Subsequently, the engine control unit 201 determines whether the computed size of the transfer medium 2 is significantly less than a minimum size of a transfer medium that is conveyable by the paper output option unit 30, that is, the engine control unit 201 determines whether a difference between the computed size of the transfer medium 2 and the minimum size of a transfer medium that is conveyable by the paper output option unit 30 is within a predetermined range (step S310). If a difference between the computed size of the transfer medium 2 and the minimum size of a recording medium that is conveyable by the paper output option unit 30 is within a predetermined range, the engine control unit 201 completes the transfer-medium size detection sequence. However, if the computed size of the transfer medium 2 is significantly less than the minimum size that is conveyable by the paper output option unit 30, the processing of the engine control unit 201 proceeds to step S310. The engine control unit 201 sends transfer-medium size mismatch information to the controller 202 (step S311). Thus, the controller 202 determines that a print failure of the transfer medium 2 occurred. The operations of the image forming apparatus and the paper output option unit 30 are stopped (step S314). Thereafter, the engine control unit 201 sends the size of the transfer medium 2 and the transfer medium number to the controller 202 (step S312). The controller 202 sends the size of the transfer medium 2 and the transfer medium number to the paper output option unit 30 (step S313).
In this way, the paper output option unit 30 can appropriately set a conveyance speed, a conveyance timing, and a jam determination timing for the transfer medium 2 in accordance with the received size of the transfer medium 2 and the transfer medium number. That is, since the paper output option unit 30 can associate the conveyed transfer medium 2 with the size information about the transfer medium 2, the paper output option unit 30 can set a jam determination timing for the transfer medium 2 in accordance with a conveyance speed, a conveyance timing, and the size of the transfer medium 2.
FIG. 14 is a flow chart of an example process performed by the engine control unit 201 in which, during duplex printing, the size of the transfer medium 2 is detected, but the detected size is not sent to the paper output option unit 30. To carry out this process, a CPU (not shown) of the engine control unit 201 reads out a control program from a ROM (not shown) and executes the control program.
The process is described in detail next with reference to FIG. 14. When the transfer medium 2 is fed, the engine control unit 201 receives a transfer medium number corresponding to the transfer medium 2 from the controller 202 (step S321) and starts feeding the transfer medium 2 (step S322). Subsequently, the engine control unit 201 determines the time to resume conveyance of the transfer medium 2 (step S323). In the case of duplex printing, when the time to resume the conveyance of a transfer medium 2 is reached, the processing is completed without detecting the size of the transfer medium 2. In the case of duplex printing, the size of the transfer medium 2 has already been detected before an image is formed on a first surface of the transfer medium 2. Accordingly, a size detecting operation is not needed. When outputting the transfer medium 2 to the paper output option unit 30, the engine control unit 201 starts a timer count (step S324). The transfer medium 2 is then conveyed. When the sensor 19 detects the passage of the trailing edge of the transfer medium 2 (step S327) (see FIG. 18C), the engine control unit 201 stops the timer count (step S328). Subsequently, the engine control unit 201 computes the size of the conveyed transfer medium 2 on the basis of a curved value when the transfer medium 2 is temporarily stopped by a roller 28, a distance between the sensor 19 and the roller 28, and a timer count value (step S328). If the sensor 19 cannot detect the trailing edge of the transfer medium 2 even when a time corresponding to a maximum size of a transfer medium that is conveyable by the paper output option unit 30 has elapsed (step S325), the engine control unit 201 sends transfer-medium mismatch information to the controller 202 (step S326). Thereafter, the engine control unit 201 determines whether the computed size of the transfer medium 2 is significantly less than a minimum size of a transfer medium that is conveyable by the paper output option unit 30, that is, whether a difference between the computed size of the transfer medium 2 and the minimum size of a transfer medium that is conveyable by the paper output option unit 30 is within a predetermined range (step S329). If the difference between the computed size of the transfer medium 2 and the minimum size of a transfer medium that is conveyable by the paper output option unit 30 is within the predetermined range, the engine control unit 201 completes the transfer-medium size detection sequence. If the computed size of the transfer medium 2 is significantly less than the minimum size of a transfer medium that is conveyable by the paper output option unit 30, the processing of the engine control unit 201 proceeds to step S330. The engine control unit 201 sends transfer-medium size mismatch information to the controller 202 (step S330). At that time, the controller 202 determines that a print failure of the transfer medium 2 occurred. The operations of the image forming apparatus and the paper output option unit 30 are stopped (step S334). Thereafter, the engine control unit 201 determines whether the output port for the transfer medium 2 is a duplex printing port (step S331). If the output port for the transfer medium 2 is not a duplex printing port, the engine control unit 201 sends the size of the transfer medium 2 and the transfer medium number to the controller 202 (step S332). The controller 202 sends the size of the transfer medium 2 and the transfer medium number to the paper output option unit 30 (step S333).
In this way, the paper output option unit 30 can appropriately set a conveyance speed, a conveyance timing, and a jam determination timing for the transfer medium 2 in accordance with the received size of the transfer medium 2 and the transfer medium number. That is, since the paper output option unit 30 can associate the conveyed transfer medium 2 with the size information about the transfer medium 2, the paper output option unit 30 can set a jam determination timing for the transfer medium 2 in accordance with a conveyance speed, a conveyance timing, and the size of the transfer medium 2.
Note that, in the present embodiment, the term “size (length) of a transfer medium” refers to the length of a transfer medium in a direction in which the transfer medium is conveyed for forming an image.
The paper output option unit is a paper handling unit. For instance, the paper handling unit includes stapler, booklet maker, and folder.
Other Exemplary Embodiments
In addition to the above-described embodiments, the following embodiments can be made.
Except for hardware having a network function, the above-described embodiments can be realized by software that sequentially performs the above-described data processing. That is, the above-described embodiments of the present invention can be realized by supplying a storage medium (or a recoding medium) storing software program code that achieves the functions of the above-described embodiments to a system or an apparatus and by causing a computer (central processing unit (CPU) or micro-processing unit (MPU)) of the system or apparatus to read and execute the software program code. In such a case, the program code itself read out of the storage medium realizes the functions of the above-described embodiments. The program code can be stored in a variety of storage media, such as a CD (compact disc), an MD (magnetic disk), a memory card, an MO (magneto optical) disc or the like.
Furthermore, the functions of the above-described embodiments can be realized by another method in addition to executing the program code read out by the computer. For example, the functions of the above-described embodiments can be realized by a process in which an operating system (OS) running on the computer executes some of or all of the functions in the above-described embodiments under the control of the program code.
The present invention can also be achieved by writing the program code read out of the storage medium to a memory of an add-on expansion board of a computer or a memory of an add-on expansion unit connected to a computer. The functions of the above-described embodiments can be realized by a process in which, after the program code is written, a CPU in the add-on expansion board or in the add-on expansion unit executes some of or all of the functions in the above-described embodiments under the control of the program code.
While the foregoing embodiments have been described with reference to an image forming apparatus serving as a laser printer, the present invention is applicable to an image forming apparatus serving as a copier having a copy function, an image scanning apparatus having only an image scanning function, a multi-function printer or the like.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications, equivalent structures and functions.
This application claims the benefit of Japanese Application No. 2006-163823 filed Jun. 13, 2006, which is hereby incorporated by reference herein in its entirety.
Patent Application
20070286614
