JPH04266338A - Paper sheet carrier device of printer - Google Patents

Abstract

PURPOSE:To provide a paper sheet carrier device for carrying a paper sheet layered on a paper sheet storage part and a paper sheet inserted from a manual feeding port to an image formation part through one feeding roller. CONSTITUTION:A paper sheet 4 on a paper sheet storage part 1 is drawn out to a paper sheet carrier passage 32 in a reversed way by the operation of one rotation of a feeding roller 23, and is thus supplied to an image formation part 31, and when the feeding roller 23 is stopped, the paper sheet 4 extracted by the rotational member of the image formation part 31 is pressed by a protrusive part 69 of a cam 68 and is separated from the feeding roller 23, so as to suppress the adhesion of paper sheet powder to the feeding roller 23. Since the cross section of the feeding roller 23 is of circular shape, even the paper sheet inserted from a manual feeding port 35 is carried to the image formation part 31 by the feeding roller 23, and paper sheets of different feeding routes can be carried by one feeding roller 23, and the installation space of a printer can be reduced thereby.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper conveying device for a printing device.

0002

2. Description of the Related Art Conventionally, as shown in FIG. 7, paper in a paper feed cassette 101 provided at the bottom of a housing 100 is pulled out while being reversed by a paper feed roller 102.
3 or inserted from the manual feed tray 104 in the direction of the arrow by the conveyance roller 103, the developed image formed on the photoreceptor 105 is transferred to the paper, and the transferred image transferred to the paper is There is a printing device in which the image is fixed by a fixing roller 106. The electrostatic latent image is formed on the photoreceptor 105 by applying a charge to the photoreceptor 105 from the charger 107.
This is carried out by charging the outer circumferential surface of , and scanning this charged portion with an optical signal corresponding to an image signal from the exposure unit 108 . This electrostatic latent image is developed by a developing device 109, and this developed image is transferred onto paper by a transfer charger 110. Further, the photoreceptor 105 is connected to a cleaning unit 111.
Cleaned by.

Furthermore, as shown in FIG. 8, the paper in the paper feed cassette 113 attached to the side surface of the housing 112 is fed to the photoreceptor 105 by the paper feed roller 102 or inserted from the manual feed tray 104. The conveyed paper is supplied to the photoreceptor 105 by the conveyance roller 103, and then the paper is transported to the housing 112.
There is a printing device that transfers the developed image on the photoreceptor 105 onto a sheet of paper during the process of discharging the paper using a paper discharge roller 115 toward a paper discharge receptacle 114 formed on the upper surface of the paper. Note that the photoreceptor 10
Since the formation and fixing of an image on the image forming apparatus 5 are the same as the principle shown in FIG.

0004

[Problem to be solved by the invention] What is shown in FIG.
Since the paper feed path for feeding paper from the paper feed cassette 113 and the paper feed path from the manual feed tray 104 are different, the paper feed roller 102 and conveyance roller 103 for feeding paper for each of these paper feed paths are different. I need. As a result, the number of parts for the paper conveyance device increases, making the device larger.

In the system shown in FIG. 7, the paper feed path from the paper feed cassette 101 is reversed and merges with the paper feed path from the manual feed tray 104, so that only the paper feed roller 102 is used to feed the paper from the paper feed cassette 101. It is conceivable to send the paper from the manual feed tray 104 to the photoreceptor 105. However, in general, the paper feed roller 102 is stopped after feeding out the leading edge of the paper in order to intermittently feed the top layer of paper in the paper feed cassette 101, and while it is stopped, the paper feed roller 102 avoids contact with the paper pulled out by the photoreceptor 105 and rolls the paper. It is necessary to suppress the adhesion of powder. This is to prevent paper conveyance force from being reduced due to adhesion of paper dust. For this purpose, the paper feed roller 102
The cross section is not circular, and part of the outer periphery is cut off. On the other hand, the conveyance roller 103 provided in the paper conveyance path must be in contact with the paper at any part of its circumference in order to continue conveying the paper, and must have a circular cross section. Therefore, a paper feed roller 102 and a conveyance roller 103 are separately provided to feed paper from the paper feed cassette and paper from the manual feed tray.

Furthermore, the paper feed cassette 1 shown in FIG.
The height of the casing 100 is increased in order to arrange the photoreceptor 105 at the top of 01 with an interval for reversing the paper.
The paper pulled out by the paper feed roller 102 is transferred to the photoconductor 1.
05, the length of the housing 100 cannot be shortened. In the case shown in FIG. 8, the height of the housing 112 can be restricted by placing the paper feed cassette 113 on a tangent to the outer circumference of the lower part of the photoreceptor 105. There is a problem that the installation area becomes large because it protrudes from the side.

[0007]

[Means for Solving the Problems] The present invention provides a paper storage section in which a large number of sheets of paper are stored in a stacked state, and a paper transport path that faces the upper surface of the paper storage section at a predetermined distance. , a paper feed roller having a circular cross section, which is rotatably provided between an end of the top layer of paper in the paper storage unit and the paper transport path, and whose length of one circumference is set to be shorter than the length of the paper. and a pair of cams that are arranged on both sides of the paper feed roller, have protrusions that partially protrude with a radius larger than the radius of the paper feed roller, and rotate integrally on the same axis as the paper feed roller. and a rotating member arranged along the paper transport path at a position away from the paper feed roller with an interaxial distance shorter than the length of one circumference of the paper feed roller, and is provided at the upper part of the paper storage section. an image forming section;
and a manual paper feed port formed at the end of the paper transport path on the paper feed roller side.

[0008]

[Operation] The paper in the paper storage section is pulled out while being reversed to the paper conveyance path by one rotation of the paper feed roller and is supplied to the image forming section. When the paper feed roller is stopped, the paper pulled out by the rotating member of the image forming section is pressed by the protrusion of the cam and separated from the paper feed roller, thereby suppressing the adhesion of paper dust to the paper feed roller. Also, since the paper feed roller has a circular cross section, the paper inserted from the manual paper feed slot is also conveyed to the image forming unit by the paper feed roller, and sheets with different paper feed paths are conveyed by only one paper feed roller. Therefore, it becomes possible to reduce the installation space of the printing device.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1 to 5. 1 and 2 are longitudinal sectional front views. In the figure,
1 is a paper storage section. The paper storage unit 1 is held movably in the width direction of the paper 4 by a flat paper feed body 2 that is slightly larger than A4 size paper 4 and a protrusion 3 formed at the bottom of the paper feed body 2. It consists of a mounting plate 5 and a pressing plate 6 which is held on the paper feed main body 2 so as to be able to rise and fall freely. Guides 7 for supporting both side edges of the paper 4 are formed on both sides of the mounting plate 5. Further, although the pressing plate 6 holds the sheets 4 in a stacked state and is biased by a spring 8 in a direction away from the mounting plate 5, the guide 7 may be provided with a stopper 9 that contacts the top layer of sheets 4. This limits excessive upward movement. Further, an electrical equipment compartment 10 is formed at the bottom of the paper feed main body 2, and the electrical equipment compartment 10 is provided with an electrical equipment case 11 and a circuit board 12 connected to the electrical parts housed in the electrical equipment case 11. It is being Electrical equipment room 1
A plurality of legs 14 are fixed to a base plate 13 that closes the bottom of the desk. Further, a lid 15 is attached to the upper surface of the paper feed main body 2 so as to be openable and closable.

[0010] A printing unit 16 is provided above the paper storage section 1. This printing unit 1
Reference numeral 6 denotes a case 18 which is rotatably held on both sides of the paper feed main body 2 by a fulcrum shaft 17, a support 19 fixed to this case 18, and a support body 19 which is rotatably held by the case 18 by a fulcrum shaft 20. It has a cover 21. A developer container 22 for storing developer is integrally formed in the case 18. The case 18 also includes a paper feed roller 23, a photoreceptor 24 which is a rotating member whose outer diameter is approximately half the outer diameter of the paper feed roller 23, and a developing roller 2.
5, and a regulating roller 26 that regulates the thickness of the developer layer.
A fixing roller 27 is rotatably held, and a motor (not shown) for driving these rotating bodies is fixed.

The support 19 includes a charger 28 that applies a voltage to the photoreceptor 24 to charge the photoreceptor 24, and a charger 28 that irradiates the charged portion of the photoreceptor 24 with a light signal corresponding to an image signal. An exposure section 29 that forms an electrostatic latent image and a photoreceptor 24
An auxiliary brush 30 that evens out the developer remaining on the outer peripheral surface of the
and a static eliminator 30a that removes the electric charge from the photoreceptor 24. The exposure section 29 is formed by arranging a large number of edge light emitting elements in a line. and,
The aforementioned photoreceptor 24, the developing roller 25 and regulation roller 26 in the developer container 22, the fixing roller 27 and the press roller 41, the charger 28, the exposure section 29, the auxiliary brush 30, and the static eliminator 30a. , and a transfer roller 39 form an image forming section 31. Here, the length of one circumference of the paper feed roller 23 is determined to be shorter than the length of the paper 4, and the paper feed roller 23 and the photoreceptor 24 of the image forming section 31
The distance between the axes is set to be shorter than the length of one circumference of the paper feed roller 23.

A paper conveyance path 32 is formed between the case 18 and the cover 21, and the paper conveyance path 32 and the extension surface (paper feed path) of the uppermost layer of paper 4 on the press plate 6 are similar to each other. , a plurality of ribs 34 connected by a reversing path 33 formed by a part of the outer circumferential surface of the paper feed roller 23, and for promoting the guiding action of the paper 4 through this reversing path 33.
is formed in the case 18. Further, a manual paper feed port 35 is formed at the end of the paper transport path 32 on the paper feed roller 23 side.

Furthermore, a paper guide surface 37 is formed on the toner cartridge 36 mounted in the developer container 22, and a paper guide plate 38 facing the paper guide surface 37 is held by the cover 21. The transfer roller 39 is rotatably held in the cover 21 in contact with the photoreceptor 24 . The paper guide plate 38 is formed of a leaf spring, and a pinch roller 40 and the press roller 41 are rotatably held at both ends thereof while being urged toward the case 18 side. As a result, the pinch roller 40 is brought into pressure contact with the paper feed roller 23, and the press roller 41 is brought into pressure contact with the fixing roller 27. Further, near the tip of the press plate 6 in the paper storage section 1, a lever 43 having a friction member 42 at the tip is biased clockwise by a spring 44 and is held rotatably about a support shaft 45. has been done. Thereby, the friction member 42 is brought into elastic contact with the outer peripheral surface of the paper feed roller 23. Further, a connector 46 for inputting power supply voltage, image signals, etc. is fixed to the case 18 of the printing unit 16, and a connector 47 connected to the circuit board 12 is provided in the paper storage section 1, These connectors 46 and 47 are connected by a cable 48.

Furthermore, the case 18 is provided with a stop lever 49. As shown in FIG. 3, this stop lever 49 is urged clockwise by a spring 50 and is rotatably held by a support shaft 51, and a stop shaft 52 facing the side edge of this stop lever 49 is attached to the case 18. It is erected on the side of the Further, a protrusion 53 is formed at the lower end of the stop lever 49 and comes into contact with the upper surface 2a of the paper feed main body 2. Here, FIG. 3 shows the paper feed main body 2.
2 is a side view showing the relative relationship between the upper surface 2a of the printer and the case 18 of the printing unit 16. FIG. That is, when the case 18 rotates upward about the fulcrum shaft 17, the relative position with respect to the upper surface 2a of the paper feed main body 2 changes. When the relative position of the upper surface 2a to the case 18 is L, the case 18 is located at the lower position and is in contact with the upper surface 2a of the sheet feeding main body 2. In this state, the upper surface 2a and the projection 53 contact each other. The rotational movement of the stop lever 49 is blocked, so that the upper part of the stop lever 49 projects into the manual paper feed port 35. When the relative position of the top surface 2a with respect to the case 18 is H, the case 18 is located at the upper position and is separated from the top surface 2a of the paper feed main body 2. In this state, the stop lever 49 is moved by the spring as shown by the imaginary line. It rotates clockwise due to the biasing force of 50, and its tip retreats below the manual paper feed port 35.

FIG. 4 is a front view showing the support structure of the case 18 of the printing unit 16 with respect to the paper feed main body 2. The fulcrum shaft 17 and the pin 54 are provided on the front and back surfaces of the case 18.
has been erected. Further, on the front and back sides of the paper feed main body 2, an L-shaped groove 55 for holding the fulcrum shaft 17 and a pin 5 are provided.
A notch 56 having an opening on the top surface into which the pin 54 is fitted is formed, and a hook 58 that is rotatably held on the support shaft 57 and latched to the pin 54 is provided. This hook 5
8 is biased in one direction by a spring 59,
Excessive rotational movement is prevented by the pin 60.

FIG. 5 shows the paper feed roller 2 partially in cross section.
FIG. 3 is a side view showing the support structure of No. 3; That is, a drive shaft 61 is provided that is connected to a motor via a spring clutch (not shown). The drive shaft 61 includes a hub 63 that is prevented from rotating by a pin 62, and a hub 63 that is fixed to the drive shaft 61 by a pin 62.
a hub 6 rotatably and slidably fitted in the axial direction of the hub 1;
4 and an elastic roller 65 that is rotatably fitted to one hub 63 and fixedly fitted to the other hub 64. The hub 64 is biased in one direction by a spring 66, and the hub 64 is biased in one direction by a spring 66.
A rotation transmitting portion 67 is formed on the opposing surfaces of the rotation transmitting portions 3 and 64 and is removably engaged with each other through a relationship between a protrusion and a groove. Further, a pair of cams 68 disposed on both sides of the paper feed roller 23 are fixedly fitted onto the drive shaft 61. These cams 68 are set to have an outer diameter smaller than the outer diameter of the paper feed roller 23, but a protrusion 69 that projects with a radius larger than the radius of the paper feed roller 23 is integrally formed on a part of the outer periphery. It is formed. These protrusions 69 have the function of pressing the top layer of paper 4 on the press plate 6 and separating the paper 4 from the paper feed roller 23 when the paper feed roller 23 is stopped. The spacing between the sides is set to match the width of the postcard.

In such a configuration, when printing using the paper 4 in the paper storage section 1, as shown in FIG. Maintain the state in which it is in contact with 2a. In this state, as described above, the tip of the stop lever 49 protrudes upward from the manual paper feed port 35, so that the paper feeding operation from the manual paper feed port 35 is prohibited. Then, when the paper feed roller 23 is driven clockwise, the sheets 4 stacked on the press plate 6 are separated one by one by the friction member 42 and pulled out, and are reversed toward the paper transport path 32 through the reversing path 33. . A photoreceptor 24 is attached to the paper 4 conveyed along this paper conveyance path 32.
The upper developed image is transferred by the transfer roller 39, and the transferred image is fixed by the fixing roller 27. The paper 4 with the image transferred in this way is discharged onto the top surface of the lid 15 of the paper storage section 1.

At this time, the paper 4 in the paper storage section 1 is pulled out while being reversed to the paper transport path 32 by one rotation of the paper feed roller 23 and is supplied to the image forming section 31. When the paper feed roller 23 is stopped, the paper 4 pulled out by the rotation of the photoreceptor 24 is pressed by the protrusion 69 of the cam 68 and separated from the paper feed roller 23, so that paper dust is prevented from adhering to the paper feed roller 23. suppressed.

In FIG. 3, the stop lever 49 is biased by a spring 50, and its protrusion 53 presses the upper surface 2a of the paper feed main body 2, and the reaction force of the pressing force acts as an upward rotational force on the printing unit 16. However, when feeding paper from the paper storage section 1, as shown in FIG. Rotational movements are prevented.

Therefore, in FIG. 4, the spring 5
When the hook 58 is rotated counterclockwise against the biasing force of the spring 50 and removed from the pin 54, the stop lever 49 is rotated clockwise due to the biasing force of the spring 50, as shown by the imaginary line in FIG. Since the projection 53 presses the upper surface 2a of the paper feed main body 2, the reaction force causes the printing unit 16 to rotate upward about the fulcrum shaft 17. As a result, as shown in FIG. 2, a gap s is formed between the left upper surface of the paper feed main body 2 and the left lower surface of the case 18. In this state, the upper end of the stop lever 49 is retracted below the manual paper feed port 35, so that paper can be fed from the manual paper feed port 35. In this case, since the paper feed roller 23 has a circular cross section, the paper 4 inserted from the manual paper feed port 35 is also continuously conveyed to the image forming section 31 by the paper feed roller 23 .

As described above, the paper 4 in the paper storage section 1 is reversed by the paper feed roller 23 and conveyed to the photoreceptor 24.
Further, the paper inserted from the manual paper feed port 35 is also conveyed to the photoreceptor 24 by the paper feed roller 23, and it becomes possible to convey sheets of different paper feed paths with only one paper feed roller 23. It becomes possible to reduce the installation space of the printing device.

Furthermore, a photoreceptor 2 is placed below the paper transport path 32.
4, the mounting position of the printing unit 16 can be lowered, and since the photoreceptor 24 is formed with an outer diameter that is approximately half the outer diameter of the paper feed roller 23, it is possible to lower the mounting position of the printing unit 16. The distance from the paper conveyance path 32 can be reduced, and each process unit for charging, development, transfer, etc. of the image forming section 31 can be easily arranged within a small space. Moreover, the image forming unit 31 can be placed without protruding from the upper surface of the paper feed main body 2 that stores the paper 4 and is placed on the desk, and the paper 4 after printing can also be placed on the lid 15 of the paper feed main body 2. Since the paper can be ejected in a small space, the installation space can be extremely small.

In this embodiment, the outer diameter of the paper feed roller 23 is set to about 20 mm, and the outer diameter of the photoreceptor 24 is set to about 10 mm. As a result, the length of the printing unit 16 in the paper feeding direction is about 70 mm, the height is about 30 mm, and the width corresponds to the width of A4 size paper 4, making it compact enough to be owned by an individual. Further, even if the size of the paper 4 to be used changes, only the width dimension of the printing unit 16 changes somewhat, and the height and length of the printing unit 16 are maintained within a certain dimension.

Although the above embodiments have been explained using an image forming section that forms images by electrophotography, the present invention is also applicable to those using an image forming section equipped with a line-type thermal head or an inkjet printer head. It is something that will be done. Further, when using an image forming section having a platen as a rotating member, the distance between the axes of the platen and the paper feed roller 23 is made shorter than the length of one circumference of the paper feed roller 23.

Note that, as shown in FIG. 6, the paper feed roller 23
An image forming unit 31 is disposed before and after the paper storage unit 1, and the paper in the paper storage unit 1 is pulled out straight to the left by the paper feed roller 23, an image is formed by the left image forming unit 31, and the paper is manually fed. A configuration is also possible in which the paper inserted from the paper slot is conveyed to the right by the paper feed roller 23 and an image is formed by the image forming section 31 on the left.

[0026]

Effects of the Invention The present invention provides a paper storage section in which a large number of sheets of paper are stored in a stacked state, a paper transport path that faces the upper surface of the paper storage section at a predetermined distance, and a paper feed roller with a circular cross section, which is rotatably provided between an end of the uppermost sheet of paper in the unit and the paper transport path, and whose length of one circumference is set to a value shorter than the length of the paper;
a pair of cams that are arranged on both sides of the paper feed roller, have protrusions that partially protrude with a radius larger than the radius of the paper feed roller, and rotate integrally on the same axis as the paper feed roller; The image forming apparatus includes rotating members arranged along the paper transport path at positions separated from the paper feed roller with an interaxial distance shorter than the length of one circumference of the paper feed roller, and is provided at the upper part of the paper storage section. Since the paper feed slot is configured to include a forming section and a manual paper feed port formed at the end of the paper transport path on the paper feed roller side, the paper in the paper storage section is transferred to the paper transport path by one rotation of the paper feed roller. When the paper feed roller is stopped, the paper pulled out by the rotating member of the image forming section is pressed by the protrusion of the cam and separated from the paper feed roller. , it is possible to suppress the adhesion of paper dust to the paper feed roller, and since the paper feed roller has a circular cross section, the paper inserted from the manual paper feed slot is also transferred to the image forming unit by the paper feed roller. As a result, sheets of paper having different paper feeding paths can be transported with only one paper feeding roller, which has the effect of reducing the installation space of the printing device.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and is a longitudinal sectional front view showing a state in which paper is fed from a paper storage section.

FIG. 2 is a vertical sectional front view showing a state of paper being fed from the manual paper feed port.

FIG. 3 is a side view showing the opening/closing operation of the manual paper feed slot by the stop lever.

FIG. 4 is a front view showing the support structure of the printing unit with respect to the paper storage section.

FIG. 5 is a longitudinal sectional side view of the paper feed roller.

FIG. 6 is a front view showing a modification of the present invention.

FIG. 7 is a front view showing the internal structure of a conventional printing device.

FIG. 8 is a front view showing the internal structure of a conventional printing device.

[Explanation of symbols]

1 Paper storage section 4 Paper 23 Paper feed roller 24 Rotating member 31 Image forming section 32 Paper conveyance path 35 Manual paper feed slot 68 Cam 69 Protrusion

Claims (1)

[Claims] 1. A paper storage section in which a large number of sheets of paper are stored in a stacked state, a paper transport path facing the upper surface of the paper storage section at a predetermined distance, and a top layer in the paper storage section. a paper feed roller with a circular cross section, which is rotatably provided between an end of the paper and the paper transport path, and whose circumferential length is set to be shorter than the length of the paper, and both sides of the paper feed roller. a pair of cams that rotate integrally on the same axis as the paper feed roller and have protrusions that partially protrude with a radius larger than the radius of the paper feed roller; an image forming unit provided at the upper part of the paper storage unit and having a rotating member arranged along the paper transport path at a position away from the paper feed roller with an interaxial distance shorter than the length of the paper; A paper transport device for a printing device, comprising a manual paper feed port formed at an end of a transport path on the paper feed roller side.