JP2941101B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus,
More particularly, the present invention relates to an image forming apparatus suitable for an electrophotographic printer or the like having a manual paper feed mechanism with an undefined paper size.

[0002]

2. Description of the Related Art Conventionally, this type of electrophotographic printer is shown in FIG.
The mechanism is as follows. That is, in FIG.
Denotes a photosensitive drum as an electrostatic latent image carrier, and 2 denotes a semiconductor laser as a light source. Reference numeral 3 denotes a rotary polygon mirror, and reference numeral 4 denotes a laser beam scanned on the photosensitive drum 1 by the rotary polygon mirror.

[0005] Reference numeral 5 denotes a charging roller for uniformly charging the photosensitive drum 1, and reference numeral 6 denotes a developing device for developing an electrostatic latent image formed on the photosensitive drum 1 with toner. Reference numeral 7 denotes a transfer roller for transferring the developed toner image to a predetermined sheet, and reference numeral 8 denotes a fixing roller for fusing the toner transferred to the sheet.

Reference numeral 9 denotes a cassette paper feed roller for feeding paper from a cassette capable of identifying a paper size to a transport path, and reference numeral 10 denotes a manual paper feed roller for feeding paper to a transport path from a manual paper feed port whose paper size cannot be identified.

Reference numeral 11 denotes a registration roller which strikes the leading end of the fed sheet to correct skew and synchronizes image writing on the photosensitive drum 1 with paper conveyance. Reference numeral 12 denotes a registration sensor for detecting the leading edge of the paper and measuring the length of the manually fed paper in the transport direction.
Is a discharge roller for discharging the sheet after fixing, and 14 is a sheet discharging sensor for detecting the presence or absence of the sheet after fixing.

FIG. 10 shows a circuit configuration of a control system for controlling such a mechanism.

In FIG. 10, reference numeral 100 denotes a printer controller which develops image code data from an external device such as a host computer into bit data necessary for printing by a printer, reads internal information of the printer by communication or the like, and displays the information. is there.

Reference numeral 101 denotes an engine control unit that controls the operation of each unit of the printer engine in accordance with an instruction from the printer controller 100 and notifies the printer controller 100 of printer internal information.

Reference numeral 102 denotes a paper transport control unit that controls driving and stopping of a motor and rollers for transporting the paper in accordance with an instruction from the engine control unit 101.

Reference numeral 103 denotes a high-voltage control unit that controls output of each high voltage for charging, development, and transfer in accordance with an instruction from the engine control unit 101.

An optical system controller 104 drives / stops the scanner motor and blinks the laser based on an instruction from the engine controller 101.

Reference numeral 105 denotes a sensor input unit for transmitting information of the registration sensor and the paper discharge sensor to the engine control unit 101.

Reference numeral 106 denotes an engine control unit 1 for controlling the temperature of the fixing unit.
A fixing unit temperature control unit that adjusts the temperature to a designated value of 01.

FIG. 11 shows a control sequence of the engine control unit 101 when manual paper feed is designated in such a control system. This flowchart shows a control sequence from when a print request signal is received from the printer controller 100 to when manual paper feeding is performed and the specified paper size is compared with the paper being actually conveyed.

First, when the power is turned on, the printer engine is initialized (S1). This initialization includes processing such as initialization of a central processing unit (CPU), which is the center of the engine control unit 101, and processing for heating the temperature of the fixing unit to a predetermined standby state. When the initialization of the printer engine is completed, the engine control unit 101 enters a state of waiting for a print request from the printer controller 100 (loop processing in S2).

Print request (/ PRNT = "LOW")
In response to this, the paper transport system including the photosensitive drum 1 is driven, and the high pressures of charging, development and transfer are started. Also, the scanner motor is started up to a specified rotation speed.

When these processes are completed, a paper feeding operation from the manual paper feeding port of the designated paper feeding port is started (S3). At this point, the registration roller 11 has stopped, and waits until the leading edge of the paper abuts. After that, when the registration sensor paper is present and the time corresponding to the time that the leading end of the paper abuts the registration roller 11 has elapsed, the manual feed operation is stopped and a vertical synchronization request signal (/ VSREQ) is output to the printer controller 100. (S4 to S5). The vertical synchronization signal (/ VSYN) is sent from the printer controller 100.
When C) is received, the driving of the registration roller 11 is started, and a count-up timer for measuring the paper size is started (S6 to S7). Then, when the registration sensor paper-out state is reached (S9), the count-up is stopped (S10). The count value is T1. Further, the engine control unit 101 has, as data, a reference value T2 of a timer value corresponding to the size specified by the printer controller 100 in advance for each size. When the registration sensor paper runs out, the engine control unit 101 performs a comparison process between T1 and T2 (S1).
1 to S13). However, at the time of comparison, a count value of ± α is added as a margin in consideration of a measurement error and a paper length error. If the condition of T2-α ≦ T1 ≦ T2 + α is satisfied, it is determined that the paper size matches the designated size. If this condition is not satisfied, it is determined that the paper size is different from the designated size, and the printer controller 1
In response to 00, a printer knot ready state is notified by flag information (S13 → S21). Once the printer is ready, the printer controller 100
Unless an instruction to change the designated paper size is received from, the printable state is not set.

FIG. 12 shows the relationship between T1, T2, and α corresponding to paper.

[0019]

However, in the above-mentioned conventional example, if a paper size mismatch is detected, for example, even if a paper larger than the designated size is passed, that is, even if the print data is not lost, an error will occur and the printer Becomes a not-ready state, and the printing operation cannot be continued.

This means that when the above-described sequence control is applied to a device that operates in an unmanned state such as a facsimile, subsequent printing cannot be performed even though print data is not lost. . For this reason, there is a problem in ease of use by the user. In view of the above, an object of the present invention is to perform error processing in which printing operation cannot be continued, based not only on paper size matching / mismatching, but also on print data loss, as a criterion. An object of the present invention is to provide an image forming apparatus capable of performing two processes of a warning process that can continue a printing operation.

[0021]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a detecting means provided on a paper conveying path, wherein the detecting means makes the length of the paper in the conveying direction equal to a designated size. Control means for stopping an image forming operation on the sheet when it is detected that the designated size is smaller than the length in the transport direction.
The detecting means should detect the trailing edge of the sheet with respect to the designated size judging means for judging the standard size and the second standard size longer in the transport direction than in the first standard size and shorter in the direction intersecting the transport direction. Storage means for storing data for specifying a near-timing range; and measurement size judging means for judging that the detection timing of the trailing edge of the sheet is within the vicinity range for the second standard size stored in the storage means. Even if it is not detected that the length of the sheet in the transport direction is shorter than the length of the designated size in the transport direction, the designated size determination means sets the designated size to the first standard size. When the measured size determination means determines that the detection timing of the trailing edge of the sheet is within the vicinity range regarding the second standard size, The serial control means is characterized in that so as to stop the image forming operation to the paper.

[0022]

According to the present invention, attention is paid to the fact that when the size of the recording paper used for recording is larger than the designated size, that is, the size of the recording image area, no loss of the recording image occurs. Is generated to continue the image forming operation. When the (detection) size of the recording paper is smaller than the designated size, the image forming operation is stopped by the image forming operation stop signal.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a basic configuration of an embodiment of the present invention.

The image forming apparatus according to the present embodiment detects the size of a fed recording sheet, and can detect an error in which the detected size of the recording sheet does not match the designated size specified in advance. It is.

In FIG. 1, reference numeral 1000 denotes a judging means for comparing and judging the detected size and the designated size in accordance with the detection of the error.

If the result of the determination by the determining means is that the detected size is larger than the designated size, the image forming operation is continued and a warning signal is generated, and the result of the determination by the determining means is The control unit generates a stop signal for stopping the image forming operation when the detected size is smaller than the designated size.

FIG. 2 shows a specific circuit configuration of the first embodiment of the present invention.

The same components as those in FIG. 2 and those in the conventional example in FIG. 10 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The engine control unit 201 of this embodiment uses an error judgment criterion 201A different from the conventional one (details are described in FIG. 4).
, An error detection process and a warning signal generation process for the recording paper are performed.

For this purpose, the printer controller 200
Information exchange is performed between the engine control unit 201 and the engine control unit 201 by serial communication. A command is sent from the printer controller 200 and the engine control unit 201 sends a status corresponding to the command. Indicates whether the engine is in a printable state or in an impossible state apart from this serial communication /
RDY signal, / VSREQ, / VSY for vertical synchronization
An NC signal or the like is exchanged between the engine control unit 201 and the printer controller 200.

FIG. 3 shows a part of the contents of the serial communication.

In the figure, a command A is sent to the engine control unit 201.
Is a command requesting the status A. Status A indicates the basic state of the printer,
These include the following status items for the printer controller 200. That is, a print request for requesting a print signal, paper transport indicating that the engine is transporting paper, misprinting indicating that a BD error or the like has occurred, or the printer is raising the temperature of the fixing device. During the wait indicating that the power supply to the heater of the fixing unit has been stopped by the instruction of the printer controller, an error that requires operator processing such as paper size mismatch, jam, or no paper has occurred. The indicated call is included in the status A.

Command B is a command for requesting status B from the engine. The status B is a status indicating the details of the status A when the call bit of the status A becomes “1”. These include a jam error that indicates that a paper jam has occurred, a paper-out error that indicates that there is no paper in the designated paper feed port, and a paper size that indicates that the paper in the manual feed paper port is different from the specified size. Includes mismatch errors.

Command C is a command for requesting the printer controller for a status 3 for issuing a warning. The status C includes a toner-out warning indicating that the remaining amount of toner is below a certain level, and if printing is continued, there is a possibility that the toner may be insufficient. A paper size mismatch warning indicating that the paper sizes of the paper passing do not match is included.

FIG. 4 shows a sequence on the engine control unit side for setting / resetting these statuses. Here, / VS from the printer controller 200
This shows a sequence after receiving the YNC signal. In this sequence, the same processing steps as those in the related art in FIG. 11 are denoted by the same step numbers.

When a print request signal is received from the printer controller 200, the engine control unit 201 performs a sheet feeding operation from a manual sheet feeding port which is a designated sheet feeding port. It outputs / VSREQ to the controller 200.

Then, from the printer controller 200 /
When the VSYNC signal is received, the stopped registration roller 11 is driven, and at the same time, a count-up timer for detecting the paper size is started. Then, it waits until the registration sensor 12 becomes out of paper, and when the paper becomes out of paper, stops the paper size detection timer and reads the value. Further, a predetermined reference timer value T2 for each paper size is read, and it is determined whether or not the condition of T2-α ≦ T1 ≦ T2 + α is satisfied. Here, α is a margin for a measurement error of the timer, a paper length error, and the like. If the above condition is satisfied, the paper size matching flag is set and the printing operation is continued (the above-described processing from S7 to S15 in FIG. 4).

If the condition is not satisfied, it is determined whether the measured paper size (corresponding to the timer value T1) is larger than the designated paper size (corresponding to the reference timer value T2). If it is determined that the measurement paper size is smaller than the designated paper size, the paper size mismatch error status bit is set to “1” and
Further, after setting the status A call bit to “1”,
The print impossible state is notified to the printer controller 200 (S100 → S101). If it is determined that the measured paper size is larger than the designated paper size, the paper size mismatch warning status (warning signal of the present invention) bit is set to "1", and the printing operation can be continued.

As described above, the engine control unit 2
01 detects a paper size mismatch, and if there is a possibility of image loss, that is, if the measured paper size is smaller than the specified size, the / RDY signal is set to “false” as an error.
e), an image formation operation stop signal is generated. If there is no possibility of image loss, only a warning is executed, and the / RDY signal retains "true" to continue printing. In a device or the like that operates in the state, it is possible to prevent a decrease in print efficiency without stopping operation unnecessarily.

By notifying the printer controller 200 in the form of a warning signal, the printer controller 200 can display a warning message or the like on a display unit (not shown). The judgment can be left to the user, and the flexibility in using the printer is improved.

<Second Embodiment> FIG. 5 shows the structure of a printer mechanism according to a second embodiment of the present invention.

In the first embodiment, the registration rollers 1
1 is provided, and vertical synchronization is performed by exchanging the / VSREQ signal and the / VSYNC signal between the printer controller 200 and the engine control unit 201.
Vertical synchronization is performed by transmitting an OP signal from the printer engine. The control system is the same as the circuit shown in FIG.

FIG. 6 is a flowchart showing a sequence operation procedure of the engine control unit 201 in the second embodiment. Also in this figure, the same processes in the conventional procedure (FIG. 11) or the procedure of the first embodiment (FIG. 4) are given the same numbers.

From printer controller 200 / PRN
When the T signal is received, the engine control unit 201 starts a sheet feeding operation from a manual sheet feeding port, which is a designated sheet feeding port, when the high-pressure startup and the scanner rotation speed are started up to the specified rotation.

Thereafter, when the paper reaches the TOP sensor, a / TOP signal is sent to the printer controller 200 (S202), and at the same time, a paper size detection timer is started (S203). Then, when the TOP sensor runs out of paper (S204), the counting of the paper size detection timer is stopped, and the subsequent processing determines the match / mismatch of the paper sizes according to the same sequence as that described in the first embodiment. (S10-S14 or S10-S13 → S21 →
S100 to S102).

<Third Embodiment> FIG. 7 shows a paper size comparison process in a third embodiment of the present invention. The mechanism and the control system may be any of the systems of the first and second embodiments.

In the flowchart of FIG. 7, it is assumed that the paper sizes that the printer can pass are only B5, A4, and LTR in the vertical direction.

When the measurement of the paper size is completed, the engine control unit 201 reads the timer value and identifies the type of the measured paper size by using the almost reference table (stored in the engine control unit 201) of FIG. (S300). Further, data of the designated paper size is read (S1).
2) It is determined whether the condition of T2-α ≦ T1 ≦ T2 + α is satisfied (S13). If the conditions are satisfied, the printing operation is continued (S14 → S15).

If the conditions are not satisfied, the size relationship between the designated size and the measurement / paper size is determined. If it is determined that the measured size is smaller, the printing operation is stopped as a paper size mismatch error (S100 → S101).
→ S103).

If it is determined that the measured size is larger, it is determined whether the designated size is the LTR (S100).
→ S301). If the designated size is LTR and the measured size is determined to be A4, the printing operation is stopped as a paper size mismatch error (S301 → S302 → S
101 → S103). For other sizes, the larger the paper length, the larger the width.
Such processing is not performed, and the determination is made only based on the paper length.

<Fourth Embodiment> In the first to third embodiments described above, the manual paper feed port whose paper size is unknown has been described. However, the present invention can be applied to the following cases. For example, even in an image forming apparatus using a cassette whose paper size can be identified, the cassette is a universal cassette corresponding to a plurality of types of paper sizes. In this case, even if the user sets a certain paper and the size frame of the cassette is not switched to the paper size correctly, the phenomenon that the size read by the printer does not match the paper size actually passed through the printer. It can happen.

In this embodiment, error processing in such a case will be described. The operation sequence of the engine control unit when the function of the first embodiment is applied to the present embodiment may use the operation sequence of FIG. 4, and when the case of the second embodiment is applied, the operation sequence of FIG. When the third embodiment is applied, the operation sequence shown in FIG. 7 is used. However, during the above-described operation sequence, the only difference is that the controller designated size is the paper size obtained by reading the cassette frame in the fourth embodiment, and the other controls remain unchanged.

[0054]

As described above, according to the present invention, when the fed recording paper is larger than the recording image area (corresponding to the designated size of the recording paper), a warning is regarded and the image forming operation is performed. Is executed, even if the image forming apparatus is installed in an unmanned apparatus such as a facsimile apparatus,
There is no need to interrupt the recording operation due to a simple paper mismatch error as in the related art.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of the first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing contents of status information according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing the contents of an operation sequence executed by an engine control unit 201 of FIG. 2;

FIG. 5 is a side sectional view schematically showing the structure of a second embodiment of the present invention.

FIG. 6 shows an engine control unit 20 according to a second embodiment of the present invention.
3 is a flowchart showing the contents of an operation sequence of FIG.

FIG. 7 shows an engine control unit 20 according to a third embodiment of the present invention.
3 is a flowchart showing the contents of an operation sequence of FIG.

FIG. 8 is an explanatory diagram showing table contents according to a third embodiment of the present invention.

FIG. 9 is a side sectional view schematically showing a structure of a conventional example.

FIG. 10 is a block diagram showing a circuit configuration of a conventional example.

FIG. 11 is a flowchart showing an operation sequence content of an engine control unit 101 of a conventional example.

12 is a plan view showing the contents of a size used for determining the presence or absence of an error in FIG. 11;

[Explanation of symbols]

 100, 200 Printer controller 101, 201 Engine control unit 102 Paper transport control unit 105 Sensor input unit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 21/00 B41J 11/42 B41J 13/00 B41J 29/48 B41J 29/50

Claims (1)

(57) [Claims] A detecting means provided on a paper conveying path;
When the detection unit detects that the length of the sheet in the conveyance direction is shorter than the length of the specified size in the conveyance direction, the control unit stops the image forming operation on the sheet. A designated size determining unit for determining that the designated size is the first standard size; and a second standard size longer in the transport direction than in the first standard size and shorter in the direction intersecting the transport direction. A storage unit for storing data specifying a range near the timing at which the trailing edge is to be detected; and a detection timing of the trailing edge of the sheet is within a neighborhood range related to the second standard size stored in the storage unit. Measuring means for determining the size of the sheet, the length of the sheet in the direction of conveyance is not detected to be shorter than the length of the specified size in the direction of conveyance. However, the designated size judging means judges the designated size to be the first standard size, and the measured size judging means sets the detection timing of the trailing edge of the sheet within the vicinity range of the second standard size. The image forming apparatus is characterized in that when the determination is made, the control means stops the image forming operation on the sheet.