JP2760518B2 - Registration adjusting device in image forming apparatus - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a registration adjusting device in an image forming apparatus such as a laser printer.

[Conventional technology]

Generally, in an image forming apparatus such as a laser printer,
When a plurality of paper feeding units are provided, the paper fed from each paper feeding unit is conveyed to the registration roller due to the parallelism of each paper feeding unit and the variation in mechanical characteristics. The position of the paper in the horizontal direction may be shifted or the position in the vertical direction may be shifted for each means.

Therefore, conventionally, a horizontal registration correction value setting unit and a vertical registration correction value setting unit including a dip switch or a volume for setting a correction value with respect to a reference value for each paper feeding unit are provided, and according to the correction value set by these. The reference value is corrected to adjust the horizontal registration and the vertical registration.

[Problems to be solved by the invention]

However, if the horizontal registration correction value setting unit and the vertical registration correction value setting unit including the depth switch or the volume are provided for each sheet feeding unit in this manner,
When the number of paper feeding means increases with the systemization, the number of registration correction value setting means must be increased, which complicates the configuration and increases the cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and enables a single correction value setting unit to set correction values of a horizontal registration and a vertical registration for a plurality of paper feeding units, thereby simplifying the configuration and reducing costs. It is intended to reduce the amount.

[Means for solving the problem]

In order to achieve the above object, the present invention provides an image forming apparatus provided with a plurality of paper feeding means, as shown in a functional block diagram in FIG. 1, of a paper feeding means for setting a correction value for registration adjustment. A sheet feeding designating unit A which also serves as a designating unit and a unit for designating which type of correction value to be set is a horizontal registration correction value or a vertical registration correction value;
One correction value setting means B for setting the correction value, and a correction value set by the correction value setting means B
And a correction value storage means C for storing the correction values stored in association with the type of the sheet correction means and the registration correction value specified by the correction value storage means. It is an object of the present invention to provide a registration adjustment device including a registration adjustment unit D for performing a horizontal registration adjustment and a vertical registration adjustment of a selected sheet feeding unit.

(Operation)

According to the registration adjusting apparatus having the above-described configuration, the correction value to be set for any one of the plurality of paper feeding units by the paper feeding specifying unit A and the correction value to be set are set to the horizontal registration correction value. And the vertical registration correction value, and the correction value is set by the correction value setting means B, so that the correction value storage means C stores the set correction value in the sheet feeding specification means. The information is stored in association with the paper feeding means and the type of the registration correction value designated by A.

Accordingly, the correction value is set by the correction value setting means B while sequentially changing the paper feeding means designated by one paper feeding designating means A and the type of the registration correction value, whereby one correction value is set. The correction value setting means B can set the correction values of the horizontal registration and the vertical registration for all of the plurality of paper feeding means and store them in the correction value storage means C.

Accordingly, the registration adjustment unit D performs horizontal registration adjustment and vertical registration adjustment of the selected sheet feeding unit according to the correction values stored in the correction value storage unit C.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a schematic configuration diagram showing an example of a laser printer as an image forming apparatus to which the present invention is applied.

A printer body 1 of the laser printer includes a laser writing unit 2 for optically scanning a photosensitive member according to an image.
And photoreceptor unit, charging charger, developing unit,
A process unit 3 for performing an image forming process such as a transfer charger and a cleaning unit; an upper paper feed cassette 4 and a lower paper feed cassette 5 for supplying paper; and a toner image developed by the process unit 3 and transferred onto paper. The fixing unit 6 includes a fixing unit 6 for fixing by heating and pressurizing, and a lower discharge tray 9 and an upper discharge tray 10 for receiving sheets fixed by the fixing unit 6 and discharged through the paper path 15. .

Further, in this laser printer, a large-volume paper feeding unit 7 provided as another option of the printer main body 1 and a sheet on which an image is formed on one side subjected to a fixing process by the fixing unit 6 are turned over and sent to the process unit 3 again. A reversing unit 8 for forming an image on both sides is provided. The printer main body 1 is mounted on the reversing unit 8, and a large-volume sheet feeding unit 7 is also mounted on the side of the reversing unit 8.

The upper paper feed cassette 4, the lower paper feed cassette 5, and the large paper feed unit 7 are provided with an upper paper feed roller 11, a lower paper feed roller 12, and a large paper feed roller 13 for sequentially sending out the paper, respectively. In front of the photoreceptor of the process unit 3, a registration roller for aligning the paper and the image (toner image) on the photoreceptor in the paper feeding direction (vertical registration adjustment).
14 are provided.

In this laser printer, formed image data such as a character code transmitted from a host such as a computer or a word processor is converted into image data (image data) by an internal controller (character generator) described later.
Then, the printer main body 1, the large-volume paper feeding unit 7 and the reversing unit 8 are controlled by a main body control unit, which will be described later, to form an image on paper.

That is, the photoreceptor 3a of the process unit 3 is rotated in the direction of the arrow by a main motor (not shown), and the surface of the photoreceptor is uniformly charged by discharging from a charging charger. The writing unit 2 irradiates the photosensitive member with laser light corresponding to the formed image (written image) to form an electrostatic latent image corresponding to the written image, and the electrostatic latent image on the photosensitive member according to the developing unit. The toner is made to adhere to the latent image to be visualized as a toner image.

On the other hand, the upper paper feed cassette 4, the lower paper feed cassette 5, and the paper feed rollers 11 and 1 of the large-volume paper feed unit 7 corresponding to the selected paper.
When one of the sheets 2 and 13 is driven to feed the sheet, and the leading end of the sheet is detected by a registration sensor (not shown), the leading end of the sheet is pressed against the registration roller 14 based on the detection result to form the sheet. The skew is corrected, and the driven paper feed rollers 11, 12, or 13 are temporarily stopped to wait for the paper.

Then, at a predetermined timing, the paper feed rollers 11, 12, or 13, which are temporarily stopped again, are driven and the registration rollers 14 are stopped.
Is driven to feed the paper to the transfer unit of the process unit 3, the paper is brought into contact with the photoreceptor 3 a at the transfer position and superimposed on the toner image, and a predetermined voltage is applied to the transfer charger at a predetermined timing to apply the toner to the toner. To the paper side to transfer the toner image on the photoreceptor 3a onto the paper.

In this way, after the paper fed from the upper paper feed cassette 4, the lower paper feed cassette 5, and the large-volume paper feed unit 7 is temporarily stopped by the registration rollers 14, the registration rollers 14 are driven to be sent to the transfer section. Thus, the vertical registration adjustment, which is the position adjustment in the sheet feeding direction, that is, the sub-scanning direction, of the relative position between the image on the photoconductor 3a and the sheet can be performed.

Therefore, in the vertical registration adjustment, for example, the pulses output in synchronization with the rotation of the photoconductor 3a are counted, and when the count value becomes a value obtained by adding the correction value to the reference value, the registration roller 14 is driven. Can be performed.

The sheet separated from the photoreceptor 3a is sent from the process unit 3 to the fixing unit 6, and the fixing unit 6 performs a process of applying pressure while heating the sheet and the toner image to melt and fix the toner image on the sheet. The sheet subjected to the fixing process is discharged to the lower discharge tray 9 or the upper discharge tray 10 via the discharge path 15, or is sent to the reversing unit 8 to be fed again.

After the transfer step, the photoreceptor 3a removes residual toner by a cleaning unit, and erases residual charges by irradiation with a neutralization lamp to prepare for the next image forming process.

FIG. 3 is a schematic plan view showing details of the laser writing unit 2 in the laser printer.

The laser writing unit 2 includes a laser diode 16 for emitting a laser beam, a collimator lens 17 for condensing the laser beam emitted from the laser diode 16 to reduce the spot, and a cylindrical lens 18.
A polygon mirror 19 for optically scanning with a rotating polygonal mirror, θ lenses 20 and 21 for correcting the direction of the laser beam so that the scanning of the light spot on the photoconductor is linear,
A mirror 22 for directing the direction of the laser beam onto the photoconductor, a mirror 23 for directing the direction of the laser beam outside the main scanning area to the synchronous detection sensor 24, and a synchronous detection sensor for detecting the beginning of each scanning cycle 24, and an optical housing 25 and the like that house these optical members while shielding them from light.

In the laser writing unit 2, the laser light emitted from the laser diode 16 in accordance with the write information is condensed by a collimator lens 17 and is incident on a siligon mirror 19 via a cylindrical lens 18; After being reflected by the mirror surface 19, it is incident on the mirror 22 via the .theta. Lenses 20 and 21, the direction of which is changed, and from this mirror 22, the charged photosensitive member 3a of the process unit 3 shown in FIG. Irradiated on top.

At this time, by the rotation of the polygon mirror 19 in the direction indicated by the arrow, the laser beam becomes a scanning beam for scanning (main scanning) from one end A to the other end B on the photoconductor, and this optical scanning is performed by the polygon mirror. 19 is repeated for each mirror surface, and at the same time, the photosensitive member 3a of the process unit 3 rotates in the direction (sub-scanning direction) orthogonal to the main scanning direction as described above,
An electrostatic latent image corresponding to the written image is formed on 3a.

The scanning beam reflected by the polygon mirror 19 is reflected by the mirror 23 via the θ lenses 20 and 21 and is incident on the synchronization detection sensor 24. Based on the detection result of the synchronization detection sensor 24, the main scanning start timing is determined. By controlling the main scanning start timing at a timing obtained by adding the correction value to the reference value, the relative position between the image on the photosensitive member and the paper is adjusted in the main scanning direction. Lateral registration adjustment can be performed.

That is, as shown in FIG. 4, after a lapse of a certain time (reference value) from the generation of the synchronization detection signal DETP, a signal Z indicating the writing start position of the image is generated, and a certain time determined by the paper size elapses from that time. A signal W indicating the writing end position of the image is generated later. Here, the timing of generating the signal Z indicating the writing start position of the image is changed within the range from the time point x to the time point y according to the set correction value. The horizontal resist is adjusted according to.

FIG. 5 is a block diagram showing a control unit of the laser printer.

The date switch 31 specifies whether the paper feeding means for setting the registration correction value is one of the upper paper feeding cassette 4, the lower paper feeding cassette 5, the large-volume paper feeding unit 7, and the reversing unit 8, and sets the correction value. Is a switch as sheet feeding designating means for designating which is a correction value of the horizontal registration or a correction value of the vertical registration.

The other date switch 32 is a switch as correction value setting means for setting a correction value of the resist.

It should be noted that, instead of these dip switches, those which output analog signals such as volumes can also be used as the sheet feeding designating means and the correction value setting means.

The non-volatile memory 33 is a correction value for storing the horizontal registration correction value and the vertical registration correction value of the upper paper feed cassette 4, the lower paper feed cassette 5, the large paper feed unit 7 and the reversing unit 8 set by the date switches 31, 32. It is a memory as storage means.

The character controller 34 converts the character code data transferred and repeated from the host HT into image data according to the selected character font, and sends it to the control unit 35.

The control unit 35 is a micro computer (CPU), I /
A control unit 35 comprising an O and a memory, etc., controls the entire laser printer.The control unit 35 takes in information from the dip switches 31 and 32 with respect to resist adjustment, and registers the resist correction value set by the dip switch 32 with the dip switch. The data is stored at a predetermined address in the nonvolatile memory 33 corresponding to the paper feeding means designated by 31.

Further, at the time of printing, a registration correction value corresponding to the selected sheet feeding means is read out from the nonvolatile memory 33 and sent to the drive control device 36 such as a motor and the image control circuit 37.

A drive control device 36 such as a motor drives and controls each part other than the on / off control of the laser diode 16 of the laser writing unit 2 of the laser printer based on an instruction from the control unit 35. Body 3a
The main roller output in synchronization with the rotation of the counter is used as a count, and the count value is corrected based on the vertical registration correction value transferred from the control unit 35.
When it reaches the count value indicating the start timing of 14,
The driving of the registration roller 14 is started.

The image control circuit 37 controls the laser writing unit 2 according to the writing image data based on the instruction from the control unit 35.
The on / off control of the laser diode 16 is performed, and for the registration adjustment, the image writing clock WCLK is counted from the input of the synchronization detection signal DETP, and this count value is used as the horizontal registration correction value transferred from the control unit 35. The light emission control of the laser diode 16 is started when the count reaches the count value indicating the writing start timing of the image corrected on the basis of.

Next, the operation of the resist adjustment in this embodiment thus configured will be described with reference to FIGS. 6 to 8. FIG.

First, the upper paper feed cassette 4, the lower paper feed cassette 5, the large-volume paper feed unit 7, and the reversing unit 8 (hereinafter, these cassettes and units are referred to as "paper feed units") using the dip switches 31, 32. A horizontal registration correction value and a vertical registration correction value are set.

For example, as shown in FIG. 6, the correction value is set by first designating a paper feed unit for which the correction value is to be set by the DIP switch 31, and the correction value to be set by the DIP switch 31 is the horizontal registration correction value. After specifying which of the vertical registration correction values, that is, the type of the registration correction value to be set, the registration switch is set by the dip switch 32.

Thus, the control unit 35 is connected to the date switch.
The registration correction value set by the dip switch 32 is stored in the address of the non-volatile memory 33 corresponding to the sheet feeding unit and the type of the registration correction value designated by 31.

For example, the upper feed cassette 4 is specified as a paper feeding unit for setting a correction value by the dip switch 31, and a vertical registration correction value as a type of the registration correction value to be set is specified. Then, the registration correction is performed by the dip switch 32. By setting the value, the set registration correction value is stored in a predetermined address “address 22” of the nonvolatile memory 33 as shown in FIG. 7, for example.

By performing the same operations, the horizontal registration correction value of the upper paper cassette 4, the vertical registration correction value of the lower paper cassette 5, the horizontal registration correction value of the lower paper cassette 5, the large paper cassette 7
The vertical registration correction value, the horizontal registration correction value of the large-volume cassette 7, the vertical registration correction value of the reversing unit 8, and the horizontal registration correction value of the reversing unit 8 are set (in any order) as shown in FIG. As described above, the set registration correction values are sequentially stored in the addresses “23 to 29” which are predetermined addresses in the nonvolatile memory 33.

Next, at the time of printing, as shown in FIG. 8, when a print command is input, the designated feeding among the upper feeding cassette 4, the lower feeding cassette 5, the large-volume feeding unit 7 and the reversing unit 8 is performed. After selecting a paper unit and reading out the vertical registration correction value and the horizontal registration correction value corresponding to the paper supply unit 8 from the nonvolatile memory 33, paper supply is started from the selected paper supply unit and the image is printed on the paper. To record.

At this time, as described above, the drive timing of the registration roller 14 is corrected in accordance with the read vertical registration correction value to perform alignment in the main scanning direction, and the image writing start position is determined in accordance with the read horizontal registration correction value. The position is corrected in the sub-scanning direction.

When the power of the printer is turned on, the registration correction value may be read from the nonvolatile memory 33 and stored in the internal RAM, and the registration adjustment may be performed using the registration correction value in the RAM.

As described above, the laser printer according to the present embodiment can set the horizontal registration correction value and the vertical registration correction value for a plurality of paper feed units by using the single switch 32 as one correction value setting unit. Becomes easier.

In the above embodiment, an example in which the present invention is applied to a laser printer has been described. However, for example, the vertical registration adjustment can be applied to an electrostatic copying apparatus or the like.

〔The invention's effect〕

As described above, according to the present invention, the horizontal registration correction value and the vertical registration correction value are set for a plurality of paper feeding units by one paper feeding designating unit and one correction value setting unit. Can be performed, the configuration of the resist adjustment can be simplified, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention, FIG. 2 is a schematic configuration diagram of a mechanical portion of a laser printer embodying the present invention, FIG. 3 is a plan view of the laser writing unit, and FIG. FIG. 5 is also a block diagram showing the control unit, and FIG. 6 is a flowchart showing the setting operation and storage processing of the registration correction value. FIG. 8 is an explanatory diagram showing an example of storing a registration correction value, and FIG. 8 is a flowchart for explaining a process at the time of printing. 1 Laser printer body 2 Laser writing unit 3 Process unit 3a Photoconductor 4 Upper paper feed cassette 5 Lower paper feed cassette 7 Large-volume paper feed unit 8 Reversed Unit 31 Date switch (paper feed specifying means) 32 Date switch (correction value specifying means) 33 Non-volatile memory (correction value storage means) 35 Control unit 36 Drive control device such as motor 37 Image control device

Claims (1)

(57) [Claims] An image forming apparatus provided with a plurality of paper feeding means, a means for designating a paper feeding means for setting a correction value for registration adjustment, and wherein the correction values to be set are a horizontal registration correction value and a vertical registration correction value. One sheet supply designating unit also serving as a unit for designating which type of value, one correction value setting unit for setting the correction value, and a correction set by the correction value setting unit Correction value storage means for storing a value in association with the paper feeding means designated by the paper feeding designating means and the type of the registration correction value, and the correction value storage means according to each correction value stored in the correction value storage means. A registration adjusting unit that performs horizontal registration adjustment and vertical registration adjustment of a paper feeding unit selected from a plurality of paper feeding units.