JPH0482765A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent rear side staining phenomenon of a transfer roller, etc., by toner flying from happening by a method wherein even when a recording medium of which size is unknown is fed, developer transfer, etc., to an image forming area which is deviated from the recording medium is suppressed. CONSTITUTION:When a recording medium of an optional size is fed from a manual paper feed means, whether the recording medium of the optional size is carried or not is respectively detected by respective recording paper detection sensors 15a-15c. Based on these respective detection output, an image mask control unit 23 controls setting of an image writing prohibited area to the recording medium of the optional size which is fed from a paper feed means (e.g. the image mask control unit 23 controls the operation of an optical system control unit 24, and vanishes the image by emitting light to an unnecessary image area.), and thus image forming to an area which is deviated from a recording medium with an unknown size is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus having a manual paper feeding mechanism capable of manually feeding a recording medium of unknown size.

[Prior Art] A conventional image forming apparatus is configured as shown in FIG. 10, for example.

FIG. 10 is a schematic cross-sectional configuration diagram illustrating an example of a conventional image forming apparatus, illustrating, for example, a laser beam printer using an electrophotographic process.

In the figure, 1 is a photosensitive drum which is an electrostatic latent image carrier; 2
is a laser beam, 3 is a polygon scanner for scanning the laser beam 2 on the photosensitive drum 1, 4 is a charger for uniformly charging the photosensitive drum 1, and 5 is a developer (toner) for electrostatic latent images. A transfer charger 6 transfers the developed toner image onto the recording paper, which is a recording medium, and a transfer roller 6 transfers the developed toner image onto the paper. 7 is a fixing device that melts the toner transferred to the paper; 8
10 is a paper feed roller for feeding paper from the paper cassette 9; 10 is a manual paper feed roller for feeding paper; 11 is a manual paper feed roller for feeding paper from the paper cassette 9;
1 is a registration roller that synchronizes the timing of paper conveyance and irradiation of image data onto the photosensitive drum 1 with the laser beam 2; 12 is a manual paper sensor for detecting the presence or absence of manual paper; 13 is a paper feed sensor for detecting the presence or absence of manual paper; A registration sensor 14 for detecting arrival is a paper discharge sensor for confirming paper discharge from the fixing device 7.

FIG. 11 is a block diagram illustrating the control configuration of the image forming apparatus shown in FIG. 10.

In the figure, reference numeral 2o denotes a printer engine control section that controls various functions inside the printer engine in response to commands from the printer controller 21, and the blink engine control section 20 operates the various control sections described below.

22 is a paper conveyance control unit that drives/stops the motor.

Paper feed roller 82 manual paper feed roller 10. Controls driving/stopping of the registration rollers 11. The image control section 23 controls the masking of the image signal sent to the optical system control section 24 so that the image signal from the printer controller 21 is masked according to the paper size to be printed, so that the image does not protrude from the paper and is not developed. ing.

The optical system control section 24 drives/stops the laser and scanner. The high voltage control section 25 controls driving/stopping of each high voltage signal for charging, development, and transfer.

The input data control section 26 sends human input signals from each sensor to the printer engine control section 20 .

The operation of the printer engine control section 2o will be described below with reference to the flowchart shown in FIG.

FIG. 12 is a flowchart illustrating the operation of the printer engine control section 20 shown in FIG. 11. In addition,(
1) to (19) indicate each step.

First, wait for a print start signal to be received from the printer controller 21. 1) Read the paper feed port designation by the printer controller 21 (2) and determine whether manual feeding is being designated. 3) If NO, then the printer will wait for the print start signal to be received from the printer controller 21. (4) On the other hand, if the determination in step (3) is YES, the printer sends the image mask signal generation data to the image control unit 23 (4). Image mask signal generation data of paper (LEGAL size if possible) is sent to the image control unit 23 (5). And motor drive,
Pre-rotation is started for driving the scanner, raising high pressure for standby of the photosensitive drum, etc. (6). When the pre-rotation is completed (7), paper feeding starts from the designated paper feed port (8), and when the paper reaches the registration sensor 13 (9).
) T, see timer set (lO), 'l”
, After the time-up of the sec timer, the paper feed roller 8
11), and outputs a vertical synchronization request signal to the printer controller 21 (12). After that, when the vertical synchronization signal is received from the printer controller 21 (13), the drive of the registration roller 11 is started (14).
), allow writing of image data to photosensitive drum 1.
5) Start writing image data to the photosensitive drum 1.

Set the timer TzSeC corresponding to the length of the paper to be printed at the same time in the paper transport direction16), and after the timer ends (
17), image writing is prohibited 18), and after that, ejection processing is performed (19), and the processing ends.

[Problems to be Solved by the Invention] However, in the above conventional example, when printing on paper whose paper size is unknown, as in the case of manual paper feeding, the printer uses manual paper as the maximum paper size that can be printed. However, even if paper of a smaller paper size is fed, there is no function to distinguish it, and the printer controller 2
Even if data for the maximum paper size is sent from 1 to 1, the data is printed directly onto the photosensitive drum 1 without masking. There was a serious problem in that the toner that was not transferred to the paper adhered to the 6th grade, and as a result, stains were generated on the back of the paper, which significantly deteriorated the image quality.

This invention was made to solve the above problems, and detects the width of a recording medium of any size fed from a paper feeding means before starting image writing, and performs image mask processing on the photoreceptor. It is an object of the present invention to provide an image forming apparatus that can suppress toner transfer based on image information in a width direction that deviates from the width of a recording medium of an arbitrary size being conveyed immediately before image writing.

[Means for Solving the Problems 1] An image forming apparatus according to the present invention includes a plurality of paper detecting means for detecting whether or not a recording medium of an arbitrary size is fed from a first paper feeding means, and An image mask control means is provided for controlling the setting of an image write prohibition slope for a recording medium of an arbitrary size fed from the first paper feeding means based on each detection output from the detection means.

[For use] In this invention, when a recording medium of any size is fed from the first paper feeding means, each sheet detection means detects the recording medium of any size fed from the first paper feeding means. Based on these detection outputs, the image mask control means controls the setting of an image write-prohibited area for a recording medium of any size fed from the first sheet feeding means, and This makes it possible to suppress image formation in areas that deviate from the recording medium.

[Embodiment 1] FIG. 1(a) is a schematic sectional view illustrating the configuration of an image forming apparatus showing an embodiment of the present invention, and the same parts as in FIG. 10 are given the same reference numerals.

In this figure, reference numerals 15a to 15c are paper presence/absence detection sensors (sensors) serving as paper detection means, and as shown in FIG. The sensors 15a to 15c are sequentially arranged at predetermined intervals in the paper transport direction at predetermined positions in the direction perpendicular to the paper transport direction (chronological arrangement). Note that this embodiment corresponds to a case where a recording medium of any size can be manually fed along the conveyance reference plane MK at one end of the apparatus, but even when the conveyance reference is in the center, the sensor This can be handled by appropriately setting the arrangement positions of 15a to 15c.

As shown in Figure 2, each size of paper has the force shown in the figure.
It will be transported to a position as shown by Izumi. That is, when a B5 size paper passes, only the sensor 15a is used, when an A4 size paper passes, only the sensors 15a and 15b are used, and when an LGL or LTR paper passes, the sensor 1
It will pass through all of 5a to 15c.

FIG. 1(b) is a block diagram illustrating the control configuration of the image forming apparatus shown in FIG. 1(a), and the same components as in FIG. 11 are given the same reference numerals.

In the image forming apparatus configured as described above, when a recording medium of an arbitrary size is fed from the first paper feeding means (manual paper feeding means), each paper detecting means (sensors 15a to 15C in this embodiment) detects whether or not a recording medium of an arbitrary size is being fed from the first paper feeding means, and
Based on each of these detection outputs, the image mask control means (the image control section 23 in this embodiment) controls the setting of an image write-prohibited area (for example, control the driving of the optical system control unit 24, emit light to unnecessary image areas and erase the image),
It is possible to suppress image formation in an area that deviates from a recording medium of unknown size.

FIG. 3 is a perspective view illustrating the detailed configuration of the sensors 15a to 15c shown in FIG. 2, and the configuration and operation will be described below.

In the figure, reference numeral 16 is a photo ink printer, and sensor 15
When the flags A-C of a to 15c are pressed down by the recording medium, the light-shielding plate D-F is moved between the slits in conjunction with this pressing operation.
It is structured so that it crosses the

At this time, a detection pulse signal as shown in the timing chart of FIG. 4 is output from the photo ink club 16 to the printer engine control section 20.

Therefore, when one flag is activated by paper, a detection pulse signal having a different number of pulses depending on each size is input to the printer engine control section 20. Therefore, by monitoring the detection pulse signal, the printer engine control unit 20 can recognize the width of the paper currently being fed (the length in the direction perpendicular to the paper conveyance direction), and based on the detection pulse signal, Set the image mask signal in the image control section 23,
Registration control becomes possible.

In this embodiment, a registration sensor 13 is provided, but instead of this registration sensor 13, a sensor 15a is used.
If a configuration is adopted in which flag A is used as a one-sided reference, if flag A is placed near the reference plane (placed in the center in the case of center reference), no matter what paper size paper is conveyed (for example, an envelope), it will always be By passing through this flag A and using the first generated detection pulse signal as the paper leading edge signal, it can also function as a registration sensor 13.

Furthermore, the trailing edge of the paper can also be detected using the detection pulse signal of this sensor 15a, and the trailing edge detection signal output from the sensor 15a can also perform masking control for the trailing edge of the paper. LGL and LT with different vertical lengths
A vertical mask for R is also possible.

The image mask processing operation during manual paper feeding in the image forming apparatus according to the present invention will be described below with reference to FIG.

FIG. 5 is a flowchart illustrating an example of an image mask processing procedure during manual paper feeding in the image forming apparatus according to the present invention. Note that (1) to (22) indicate each step.

First, when a print start signal is received from the printer controller 21, (1) the paper feed slot designation is read from the printer controller 21 (2), and it is determined whether the paper feed slot designation is manual paper feeding or not. 3) If YES Proceed to step (5) and later, and if No (cassette paper feed specified),
Read the cassette size and set mask data based on that data (4) Next, start the pre-rotation process 5), and when the pre-rotation is finished (6), determine whether it is movable while manual paper feeding is specified 7 )NO
If so, proceed to step (8) and execute cassette paper feeding processing.

On the other hand, in the determination in step (7), the manual paper feed roller 10
9) The timer in the printer engine control unit 20 is set to T, 5ec (after manual paper feeding, the paper reaches the sensor 15a).
Set the time required to pass through all the flags A-C of ~15c and reach the registration sensor 1310), and determine whether or not the paper size pulse signal is received from the sensors 15a-15c11) , the number of pulses received during the timer activation of T3sec is incremented by 1 (12), and it is determined whether the timer has finished Ta5ec over time (13), and if NO, returns to step (ll) and YES. If so, the counted pulse number count n is confirmed to be valid, and it is determined whether the pulse number count n is "1" (14). If YES, the manually fed paper is determined to be B5 size, and the B5 size mask is determined. Set the control signal to the image control unit 2315
), proceed to step (19) and subsequent steps.

On the other hand, if the determination in step (14) is NO, it is determined whether the pulse number count n is "2" (16) and NO.
If so, proceed to step (18), and the manually fed paper size is determined to be LTR, LGL, and the paper size is LTR.
, LGL are set in the image control section 23, and the process proceeds to step (19) onwards.

On the other hand, if the determination in step (16) is YES, the manually fed paper is determined to be A4 size, and a mask control signal for A4 size is set in the image control unit 23 (17).
.

Thereafter, the system waits for the manually fed paper to be conveyed to the position where the registration sensor 13 is disposed (19), and when it reaches the position, the manual feed roller 10 that feeds the manually fed paper is stopped (20), and the registration control processing routine is executed. Execution 21),
A paper discharge processing routine is executed (22), and the processing ends.

In the above embodiment, a case has been described in which the sensors 15a to 15c are arranged at predetermined intervals in the paper conveyance direction, that is, arranged in chronological order, but as shown in FIG. Paper presence detection sensor (
The sensors 17 to 19 may be arranged in a row at the same predetermined position between the registration roller 11 and the manual paper feed roller 10 and perpendicular to the paper conveyance direction.

FIG. 6 is a schematic sectional view illustrating the configuration of an image forming apparatus showing another embodiment of the present invention, and the same components as in FIG. 1 are given the same reference numerals.

FIG. 7 is a perspective view showing the arrangement positions of the sensors 17 to 19 shown in FIG. 6, and the same components as in FIG. 2 are given the same reference numerals.

FIG. 8 is a perspective view illustrating the detailed configuration of the sensors 17 to 19 shown in FIG.
The structure is such that each photo ink printer 1
The 3-bit output from 6 is as shown in FIG.

FIG. 9 is a timing chart illustrating the detection pulse signal states of the sensors 17 to 19 shown in FIG.
) is when B5 size paper is manually fed and sensor 17~
(b) corresponds to the output when A4 size paper is manually fed and passes over the sensors 17 to 19, and (C) corresponds to the output when the paper is passed over the sensors 17 to 19.
This corresponds to the output when L size paper is manually fed and passes over the sensors 17 to 19.

In the above embodiment, the H level of the detection pulse signal is processed as being valid, but the detection pulse signal may be processed as being L level as valid.

In the image forming apparatus configured as described above, the printer engine control unit 20 sets the output timing of the image write inhibit signal in the main scanning direction to the image control unit 23 based on the input state of the 3-bit detection pulse signal, and detects the size unknown. When a recording medium is manually fed, image formation outside the recording medium area can be restricted, and toner transfer to the transfer system can be effectively restricted.

[Effects of the Invention] As explained above, the present invention includes a plurality of paper detecting means for detecting whether or not a recording medium of any size fed from the first paper feeding means is conveyed, and a An image mask control means for controlling the setting of an image writing prohibited area for a recording medium of an arbitrary size fed from the first paper feeding means based on each detection output is provided, so that a recording medium whose paper size is unknown is Even when paper is fed from the first paper feeding means, it is possible to perform image mask processing commensurate with the width size of the fed recording medium. Therefore, even if a recording medium of unknown paper size is fed, the transfer of developer to the image forming area that deviates from the recording medium is suppressed, and this is an excellent feature that prevents the back side of the transfer roller etc. from becoming dirty due to toner scattering. It has a great effect.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic sectional view illustrating the configuration of an image forming apparatus showing an embodiment of the present invention, and FIG. 1(b) is a control configuration of the image forming apparatus shown in FIG. 1(a). FIG. 2 is a perspective view showing the arrangement position of the sensor shown in FIG. 1(a), and FIG. 3 is a perspective view showing the detailed configuration of the sensor shown in FIG. 2. , FIG. 4 is a timing chart for explaining the state of the detected pulse signal of the sensor shown in FIG. 2, and FIG. 5 is for explaining an example of the image mask processing procedure during manual paper feeding in the image forming apparatus according to the present invention. Flowchart, FIG. 6 is a schematic sectional view illustrating the configuration of an image forming apparatus showing another embodiment of the present invention, and FIG.
FIG. 8 is a perspective view showing the arrangement positions of the sensors shown in the figure.
FIG. 6 is a perspective view illustrating the detailed configuration of the sensor shown in FIG. 6, FIG. 9 is a timing chart illustrating the detection pulse signal state of the sensor shown in FIG. 6, and FIG. 10 is an example of a conventional image forming apparatus. A schematic cross-sectional configuration diagram, FIG. 11, for explaining the
FIG. 10 is a block diagram illustrating the control configuration of the image forming apparatus, and FIG. 12 is a flowchart illustrating the operation of the printer engine control section shown in FIG. 11. In the figure, 20 is a printer engine control section, 21 is a printer controller, 15a to 15c are sensors, and 16 is a photo ink printer. Figure Figure Figure Figure (b) +5b Figure Figure Figure Figure Photo Ink Rack Output Figure Figure Figure Figure

Claims (1)

[Claims] In an image forming apparatus including a first paper feeding means for feeding a recording medium of an arbitrary size and a second paper feeding means for feeding a recording medium of a standard size, a plurality of paper detecting means for detecting whether or not a recording medium of any size is conveyed; and recording of an arbitrary size fed from the first paper feeding means based on each detection output from these paper detecting means. An image forming apparatus comprising: an image mask control means for controlling setting of an image write prohibited area on a medium.