JPH02287562A - Image recorder - Google Patents

Abstract

PURPOSE:To improve the accuracy of a lateral position and to prevent color slippage by performing lateral-directional positioning with respect to plural main parts which affect the accuracy of the lateral position of an image recorded on paper by means of a stay member with high rigidity. CONSTITUTION:Right and left side plates 102 and 103 composed of iron plates are lapped and fixed with a screw to a bottom plate 101 and the main stay 100 composed of an iron plate which has the thickness of about 1.6mm and high rigidity is also lapped and fixed with the screw from the outside of the plates 102 and 103. A laser scanner unit 105 is positioned and fixed on the top of the main stay 100. A paper laterally registering and refeeding unit 111 is positioned on the main stay 100 in a lateral direction by a projecting part 113 and a slit type square hole 117 and also in a vertical direction by fitting a projecting part 116 on a square hole 119. Thus the accuracy of the lateral position of the image to be printed on the paper is improved without special adjustment only by mutually maintaining the accuracy of the positioning sizes of the main stay 100.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to image recording devices such as copying machines, laser printers, LED printers, and liquid crystal printers. The present invention relates to means for improving positional accuracy.

(B) Conventional technology Conventionally, this type of image recording apparatus usually consists of a bottom plate made of an iron plate, a plurality of side plates, and a plurality of stays supporting between the side plates, and includes an optical system, a paper feed unit, and a double-sided Alternatively, the units that control the accuracy of horizontal registration and the like during multiple printing are each positioned and fixed to the bottom plate, side plate, stay, etc. while maintaining the necessary accuracy.

(c) Problems to be Solved by the Invention However, in the configuration of the image recording device as described above,
Due to the accumulation of tolerances such as component accuracy and assembly accuracy of the parts attached to each unit, there may be considerable deviations and variations in the lateral position accuracy between units, and the lateral position accuracy of the image printed on paper may also be affected by these. There was a drawback that the condition worsened depending on the deviation and variation.

In order to eliminate these drawbacks, it is possible to assemble the unit by adjusting the horizontal position of the jig, or to actually print an image on paper during the inspection process, measure the horizontal position of the image, and then adjust the unit based on that. In some cases, printing accuracy was guaranteed by adjusting the lateral position of the printer and assembling the printer, but as mentioned above, this was a major drawback in terms of assembly and workability.

In addition, with these methods, even if the printing accuracy satisfies the standard when shipped from the factory, when the unit is replaced for maintenance etc. in the market, it is difficult to restore the state to the state before replacement. This was not a desirable method from the point of view of serviceability.

Furthermore, there is a method of suppressing the precision of parts such as side plates, bottom plates, stays, etc. to which each unit is attached without adjustment, but this may result in poor yields due to processing problems.
It was quite disadvantageous in terms of cost. In this way, there is a limit to machining accuracy, and even if part accuracy is kept very strictly, for example, when attaching three units to three parts, the three tolerances will accumulate, so the final result will be There was considerable inconsistency and variation.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image recording device that eliminates the above-mentioned problems by using a highly rigid member as a stay disposed between two side plates that support the main components of the device. .

(:) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. For example, as shown with reference to FIGS. 1 and 2, the main body bottom plate (100) covers almost the entire surface of the device. In an image recording device having two side plates (102, 103) erected at right angles to the main body bottom plate (Zoo) above the main body bottom plate (100), the basic structure of the support part is , the two side plates (102, 10
3) has a stay (100) that connects and supports the paper, at least one of the stays is made of a highly rigid member, and the highly rigid stay member affects the lateral position accuracy of the image recorded on the paper. Multiple main parts giving <105,11
1,120) is characterized in that positioning in the lateral (left and right) direction is performed.

(n) Both side plates 102 and 103 erected on the bottom plate 101 of the action main body
are positioned, connected, and supported by a main stay 100 made of a highly rigid member. As a result, the relative positional accuracy of the main components mounted on the side plates 102, 103 and the main stay 100 is maintained without any special adjustment. In addition, the highly rigid main stay 1
By connecting and supporting the side plates 102 and 103 with 00, the strength of the main body of the device is increased.

(F) Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.The illustrated apparatus is a laser printer equipped with an automatic double-sided printing mechanism using a process cartridge.

FIG. 3 is a schematic longitudinal sectional side view of a laser printer to which the present invention is applied. In this device, a laser beam corresponding to an image signal to be recorded is emitted as image light from a laser scanner unit 10, and this image light is uniformly charged by a primary charger 1 while rotating in the direction of the arrow. An electrostatic latent image is formed on the drum 2. Photosensitive drum 2
The electrostatic latent image formed thereon is developed with toner from a developing device 3, and transferred to a transfer charging roller 5.

On the other hand, the sheets P are conveyed one by one to the registration rollers 9 through the rotation of the sheet feed roller 6 and a multi-feed prevention mechanism using a known glue roller rough. The paper P stops here once to form a loop to correct the skew, and is then conveyed to the transfer section in synchronization with the image on the photosensitive drum 2, where the toner image on the photosensitive drum 2 is transferred. The toner is sequentially transferred onto the paper P, and the toner remaining on the photosensitive drum 2 without being transferred onto the paper P is collected by the cleaner 10.

Note that the photosensitive drum 2, the developing device 3, the cleaner 1o, the charger 1, etc. are integrated as a known process cartridge.

Now, the paper P on which the toner image has been transferred is sequentially separated from the photosensitive drum 2, passed through the conveyance guide plate 11, and then transferred to the fixing device 12.
The toner image is fixed. In the case of one-sided printing, the flapper 13 is in the solid line state in the figure, and the paper P is conveyed along the upper guide plate, and is placed onto the tray 15 with the image side down (face down) by a pair of paper ejection rollers having a curl removal mechanism. ) and then discharged and loaded.

Next, when performing automatic double-sided printing, use flapper 1.
3 is switched to the broken line state, and the sheet P on which the - side is printed is conveyed along the lower guide plate and conveyed by a pair of conveying rollers 16 and 17 having a curl removal mechanism. When the trailing edge of the paper P passes through the transport roller pair 17 while being detected by a detection member (not shown), the half-moon-shaped forward/reverse roller 19 makes one rotation counterclockwise, and the trailing edge of the paper P reaches the reversal branch point 20. move on.

At this time, since the forward/reverse roller 19 has a half-moon facing downward as shown, the paper P is in a free state, and the lateral registration of the paper P is corrected here by a method not shown. This is because the conveyance position of the paper P deviates from the standard while being conveyed through a long conveyance path after printing the first side.
This process corrects skewing and shrinkage of the paper P during fixing to improve printing accuracy on the second side, and is essential for automatic double-sided printing apparatuses.

Next, the forward/reverse roller 19 rotates three times clockwise, and the paper P
are conveyed to the registration rollers 9 via the paper refeed roller 21, and thereafter are printed, discharged, and stacked through the same process as the first side.

The process from feeding the paper P to discharging the paper P is as described above.
The configuration of a unit that controls printing accuracy, particularly lateral registration accuracy, will be explained using FIGS. 1 and 2.

FIG. 1 is an exploded perspective view of the main body bottom plate, side plate, main stay scanner unit, lateral registration refeed unit, etc. that constitute the image recording apparatus.

First, the configuration of the main body frame will be explained. The right side plate 102 and the left side side plate 103, which are made of iron plates with a thickness of about 11 cm, are fixed from above to the bottom plate 101 made of a similar bottom plate with screws, and the main stay is made of a highly rigid iron plate with a thickness of about 1.6 cm. 100 connects the left and right side plates 102, 103.
As a supporting stay member, both side plates 102 and 103 are also fixed with screws from the outside.

A laser scanner unit 105 is positioned and fixed above the main stay 100. That is,
Positioning boss 1 such as φ6f8 from the bottom of the unit
09 and 110 protrude, and this positioning boss 10
9 and 110 are the positioning holes (for example, φ6H8) 106 and round holes (for example, 6H8) drilled on the top surface of the main stay 100.
8x8) 107, and is fixed to the main stay 100 with four screws shown in the figure.

Furthermore, a lateral registration refeeding unit 111 is positioned and fixed on the vertical surface of the main stay 100, and a paper feeding unit 120 is further positioned. First, regarding the horizontal registration refeeding unit 111, a protrusion 113 as shown in the figure is formed at the tip of the unit left side plate 112 made of an iron plate with a thickness of about 1 to 2 cm, and a protrusion 113 as shown in the figure is formed at the tip of the unit left side plate 115. Also, a protrusion 116 having the same height and shape as the protrusion 113 is formed.

On the other hand, on the vertical surface of the main stay 100, the 113.
A square hole is bored at a position corresponding to 116, and the square hole 117 corresponding to the protrusion 113 has a slit shape with a width of 1.2 mm, and the square hole 119 corresponding to the protrusion 116 has a width of about 3 mm. . FIG. 4 shows the positioning and fitting state of the main stay 100 and the lateral registration refeeding unit 111. FIG. 4(b) shows the state before fitting, and FIG. 4(a) shows the state after fitting.

That is, the horizontal registration refeeding unit 111 has a protrusion 113 and a slit-shaped square hole 117 with respect to the main stay 100.
Positioning is performed in the lateral direction (horizontal direction), and positioning in the height direction is also performed by fitting the protrusion 116 and the square hole 119.

Next, in the paper feeding unit 120 shown in FIG.
00 square holes 123 and 125, and positioning is performed in the lateral direction (left-right direction) and height direction.

As described above, the main stay 100 with high rigidity is used to position all the units responsible for horizontal image registration, such as the laser scanner unit 105, paper feeding unit 120, and horizontal registration refeeding unit 111, in the horizontal direction (horizontal direction). Since this is done, the accuracy of the lateral position of the image printed on the paper P can be improved without any special adjustment by simply maintaining the mutual accuracy of the positioning dimensions of the main stay 100. .

In particular, recent printers are required to improve total print (image) quality such as higher definition and higher print (image) position accuracy, and the present invention can meet the above requirements. effective. Further, even on paper P on which the format of a slip, form, etc. is printed in advance, there is only a printing position, and it is possible to print at a predetermined position with high precision.

Furthermore, the above-mentioned main stay 100 has main body side plates 102.
, 103, it goes without saying that the strength of the main body is improved.

FIG. 5 shows another embodiment of the invention.

The device shown in the figure positions and fixes the scanner unit and paper refeeding unit relative to the paper feeding unit and integrates them.
This increases the mutual positional accuracy between the three units.

That is, the scanner unit 105A is positioned on the upper part of the paper feed unit frame 131 in the lateral direction (horizontal direction) by fitting the positioning boss, round hole, and round elongated hole in the same way as in the first embodiment described above, and then fixed with screws. Fixed by

Further, a horizontal registration refeeding unit 111A having a similar configuration is positioned and fixed between the lower part of the paper feeding unit frame 131 and the lower part of the paper feeding unit frame 131.

Even in the above configuration, since the mutual lateral positional accuracy between the units is improved, the lateral positional accuracy of the image printed on the paper P is also improved. In addition, since the paper feed unit frame 131 is fixed to both side plates 102 and 103 of the main body, the first
Since it functions as a stay as in the embodiment, it is also effective in increasing the strength of the main body.

In the two embodiments described above, each unit was positioned and fixed with screws, but it is of course possible to perform only positioning and fixing with another member.

Further, the positioning method is not limited to the above-mentioned embodiment, and various known methods may be used.

Further, in the second embodiment, the scanner unit 105 and the lateral registration refeed unit 111A are fixed to the paper feed unit frame 131 as a base, but the present invention is not limited to this.

(g) As described in detail, according to the present invention, a unit that controls the horizontal position of the image is attached to highly rigid members such as the main stay that connects and supports the left and right side plates of the main body, and the paper feeding two-knit frame. beside(
By performing positioning in the left and right directions, it is possible to make special adjustments and improve the lateral position accuracy of images printed on paper.

In addition to improving the accuracy of printing positions on double-sided printing and pre-printed paper, it also improves color shift when printing multiple images using multi-color printers, full-color printers, etc., which are rapidly becoming popular in recent years. However, the present invention makes a significant contribution.

Furthermore, since the left and right side plates of the main body are connected and supported by the above-mentioned main stay, etc., it is effective in increasing the strength of the main body.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of the main parts of an image recording apparatus showing a first embodiment of the present invention, FIG. 5(a) is a perspective view showing another embodiment of the present invention, and FIG. 5(b) is a side view of the positioning fitting portion of the horizontal registration refeeding unit. 100... Main stay 101... Main body bottom plate 102... Right side plate 103
...Left side plate 105...Laser scanner unit 111...Horizontal registration paper refeed unit
112...Unit left side plate 115-...Unit left side plate 120...Paper feeding unit 131...Paper feeding unit frame.

Claims (1)

[Claims] 1. The device has a main body bottom plate that covers almost the entire surface of the device, and two side plates that stand above the main body bottom plate at right angles to the main body bottom plate, and provide basic support for the main components of the device. The image recording apparatus has a stay that connects and supports the two side plates, and at least one of the stays is made of a highly rigid member, and the highly rigid stay member records images on the paper. An image recording device characterized in that a plurality of main parts are positioned in the lateral (left and right) direction, which affects the lateral position accuracy of an image. 2. The image recording apparatus according to claim 1, wherein the main components include an optical system unit such as a laser scanner, an LED head, and a liquid crystal shutter array, a paper feed unit, and a lateral registration unit in a duplex/multiple printed paper conveyance path.