JP3404921B2 - Roll paper feeder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll-shaped recording paper which is pulled out by a predetermined length and cut by a rotary cutter.
The present invention relates to a roll paper feeder for supplying an image forming apparatus such as a printer or a plotter, and more particularly, to maintain a relative positional relationship between a rotary blade (or a swing blade) of a rotary cutter and a fixed blade. To a roll paper feeding device. 2. Description of the Related Art In a large-size electronic copying machine or the like that handles large-size paper such as A0 size or A1 size, unlike an electronic copying machine using a normal cut sheet, a roll paper is mounted in a roll paper storage unit. The roll paper is cut into a predetermined length based on the length information of the document, and is used as recording paper. A rotary cutter is used for cutting the recording paper. As is well known, a rotary cutter includes a rotating blade or a swinging blade (hereinafter, represented by a rotating blade) and a fixed blade.
The driving means is energized to rotate the rotary blade in one direction, and the recording paper is cut by continuously rubbing the blade edge with the fixed blade. On the other hand, in the oscillating blade, the driving means is urged to oscillate the oscillating blade, and the recording paper is cut by continuously rubbing the blade edge thereof with the fixed blade. [0003] In the rotary cutter having such a configuration, the relative positional relationship between the rotary blade and the fixed blade is shifted, and if the distance between the blades to be rubbed is widened, poor cutting of thin paper occurs. In addition, when the interval between the blades is reduced, an excessive driving force is required for cutting the thick paper. Accordingly, in the rotary cutter, it is necessary to firmly position and fix the rotary blade and the fixed blade so that the relative positional relationship between the rotary blade and the fixed blade is always kept constant. [0004] As for the structure of a rotary cutter, a rotating blade and a fixed blade are supported by sheet metal frames at both ends thereof, as described in, for example, JP-A-61-173889. Then, the sheet metal frame is fixed by bringing its flat bottom surface into surface contact with the device frame or the like and screwing it. [0005] The device frame of the roll paper feeding device is generally made of sheet metal from the viewpoint of cost and weight, and it is difficult to manage the flatness thereof. Further, since high rigidity is not required for the device frame, deformation such as "twisting" or "distortion" is likely to occur. Therefore, when the sheet metal frame of the rotary cutter is brought into surface contact with the apparatus frame and fixed by screwing, as in the above-described prior art,
The "twist" or "distortion" of the sheet metal frame also affects the sheet metal frame of the rotary cutter. Therefore, even if the relative positional relationship between the rotary blade and the fixed blade is accurately maintained on the sheet metal frame, the positional relationship between the blades is shifted in an actual use state fixed to the apparatus frame. was there. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art, and to provide a rotary blade and a fixed blade even if the object to which the rotary cutter is fixed is deformed such as "twist" or "distortion". It is an object of the present invention to provide a roll paper feeder that can always maintain the relative positional relationship accurately between thin paper and thick paper at high speed. According to the present invention, there is provided a roll paper feeder having a rotary cutter for cutting roll paper in accordance with the size of document information. The rotary cutter is constituted by a pair of rotary blades and fixed blades, and a support frame that supports the rotary blades and fixed blades while maintaining their relative positions in a predetermined relationship, and the rotary cutter support frame is It is characterized in that the object to which the support frame is fixed is brought into contact with only three small areas. [0008] Since only one plane passes through any three points in the space, "twisting" or "distortion" occurs in the fixed object, and the relative positional relationship between the three small areas is shifted. Even if
Since the support frame is fixed on a plane uniquely determined by the three new small areas after the positional relationship has shifted, even if “twisting” or “distortion” occurs in the fixed object,
This will not be transmitted to the support frame to cause a "displacement" in the relative positional relationship between the rotary blade and the fixed blade. FIG. 1 is a perspective view of a large-sized printer to which a roll paper feeder of the present invention is applied, and an image forming apparatus 1 for forming an image on recording paper, and a roll on the image forming apparatus 1. The image forming apparatus 1 includes a roll paper feeding device 3 for feeding paper and cut paper feeding devices 4 and 5 for feeding cut paper to the image forming apparatus 1. The recording paper after image formation is discharged onto a recording paper discharge tray 7 provided at the top of the printer. The roll paper feeder 3 can accommodate a plurality of roll papers. As will be described in detail later, the paper drawn from each roll paper is cut into a predetermined length to form an image. A mechanism for feeding paper to the unit 1 is provided. Similarly, the cut sheet feeding devices 4 and 5 are provided with a mechanism that feeds the stacked cut sheets to the image forming unit 1 while separating the cut sheets one by one. Further, a manual paper feed unit 6 is provided on a side surface of the image forming apparatus 1, and it is also possible to manually supply cut paper. A message such as a paper jam or an out of paper is displayed on the operation display unit 8 of the image forming apparatus 1. FIG. 2 is a perspective view showing a state in which the roll paper feeding device 3 is pulled out from the printer main body. In this embodiment, two roll papers 11a and 11b are accommodated. A rail mechanism 10 is provided on a side surface of the roll paper feeder 3, and the roll paper feeder 3 is configured to be pulled out by the rail mechanism 10 in a direction perpendicular to the roll paper transport direction. Although the cut sheet feeders 4 and 5 can be pulled out of the printer main body in the same manner as the roll sheet feeder 3, they are not shown here. A paper quality selection switch 17 and a paper type selection switch 18 are provided on the front upper portion of the roll paper feeding device 3 for each roll paper. When the roll paper is set, the paper quality of the paper and the roll used are set. Which paper is registered is registered. FIG. 3 is a cross-sectional view showing a schematic configuration of a paper transport path inside the printer. In the roll paper feeding device 3, the recording paper 20 fed from the roll papers 11 a and 11 b by the feed roller 22 forms an image via a rotary cutter 25 and a transport roller 36 disposed on a paper transport path 23. The paper is supplied into the paper transport path 24 of the apparatus 1. On the other hand, the cut sheet feeding devices 4, 5
Then, the stacked cut papers 30a and 30b are drawn into the paper transport path 32 one by one, and are transported by the transport rollers 31a to 31e.
Is supplied to the inside of the image forming apparatus 1. In the image forming apparatus 1, the recording paper 20 supplied into the paper transport path 24 is transported downstream by the transport roller 51, reaches the image transfer unit via the registration roller device 27, and forms the photosensitive drum 26. The transferred toner image is transferred by discharging the transfer corotron 28. The recording paper onto which the toner image has been transferred is guided to the fixing device 42 by the vacuum transport device 41. The recording paper on which the fixing is completed is discharged onto the recording paper discharge tray 7 by the discharge roller 43. The discharge roller 43 is constituted by a pair of rollers having a concave and convex shape, and gives corrugation to the discharged recording paper by corrugation so that the discharged recording paper can be neatly arranged on the recording paper discharge tray 7. The clamshell 9 including the recording paper discharge tray 7 can be opened to a broken line position 9 'by operating a handle (not shown), thereby removing a paper jam and improving maintainability. FIG. 4 is a cross-sectional view more specifically showing the configuration of the paper transport path in the roll paper feeder 3, and the same reference numerals as those described above denote the same or equivalent parts. Roll paper 11a, 11b of A3 size to A1 size can be mounted on the roll paper feeder 3, and each roll paper is fed by a feed roller 22a, 2
2b selectively feeds at a constant speed V (mm / sec). The feed rollers 22a and 22b also have a function of rewinding the roll paper remaining after the cutting operation in a direction opposite to the above-described paper feed direction. Downstream of the feed rollers 22a and 22b and in front of the junction 15, reflection photosensors 14a and 14b for detecting the width of the recording paper are provided, respectively. In the initialization operation, the roll paper 11a
The recording paper pulled out from (11b)
Photo sensor 14a (14b) by 2a (22b)
After the sheet is sent out to the detection position and the size is detected, when the leading end position reaches the merging portion 15 of the sheet conveying path, the apparatus enters a standby state. A rotary cutter 25 is provided downstream of the junction 15. When the rotary cutter 25 receives the cut operation signal in response to the document length information,
The driving means (not shown) is urged to rotate the rotary blade 251, and the cutting edge 251 a is continuously rubbed with the fixed blade 252 to cut the recording paper into a predetermined length. Since the recording paper continues to be conveyed even during cutting by the rotary cutter 25, the rotary cutter 25 is mounted obliquely with respect to the paper conveyance direction so that the cut portion is perpendicular to the conveyance direction. Downstream of the rotary cutter 25, there are provided a conveying roller 36 and a reflection type photo sensor 34 for detecting the leading end of the roll paper. The transport roller 36 is disposed to face the encoder wheel 38, and the encoder wheel 38 rotates following the running of the roll paper,
A pulse signal corresponding to the rotation amount is output from the encoder. This pulse signal is input to a control system (not shown) as a signal representing the roll paper transport amount after the leading edge of the recording paper reaches the photo sensor 34, so that the transport length of the recording paper can be recognized. ing. Note that the encoder wheel 38 is formed of a metal disk-shaped body so that the friction coefficient is maintained at a constant value regardless of the quality of the recording paper being conveyed. The control system converts the received pulse signal into a transport length, and issues a cut operation signal to the driving device of the rotary cutter 25 when the transport length of the roll paper reaches a predetermined length. The photo sensor 34 is also used for detecting the leading edge of the roll paper, the paper jam at the trailing end of the roll paper after cutting, and the remaining roll paper other than during the paper feeding operation. Below the roll paper mounting portion, fulcrums 44a,
The levers 45a and 45b that rotate about the roll 44b are arranged so as to be pressed against the outer peripheral surfaces of the roll paper 11a and 11b. The rotation angles of the fulcrums 44a and 44b are detected by a sensor (not shown), and when the distance δ between the outer diameter of the remaining roll paper and the outer diameter of the core 57 becomes 8 mm or less, a signal indicating that the remaining amount is insufficient is sent to the control system. Is displayed on the operation display section 8 to inform the operator that the remaining amount of recording paper has become low to urge the operator to prepare for replenishment. FIG. 5 is a diagram specifically showing the configuration of the area surrounded by the broken line A in FIG. 3. FIG. 5A shows the state in which the upper baffle 50 provided on the paper transport path 24 is closed. FIG. 4B shows a state in which the upper baffle 50 is open. The upper baffle 50 on the paper transport path 24 is generated on the recording paper when the registration roller 27 temporarily stops the leading edge of the paper to synchronize the toner image formed on the photosensitive drum 26 with the recording paper. The cam mechanism 54 is rotated when the leading edge of the sheet is detected by the registration sensor 52, and the upper baffle 50 is opened by rotating the lever 53 about the shaft 53a. It has become. At this time, the nip caused by the transport rollers 51a and 51b is also eliminated, so that the recording paper is in a free state. The deflection of the recording paper also serves to absorb the impact on the paper when the roll paper is cut by the rotary cutter 25 in the roll paper feeding device 3. FIG. 6 is a diagram showing a configuration in which the roll paper core 57 is supported at both ends. The bearing member 46 provided coaxially with the central axis of the core 57 is sandwiched between the side surface of the groove and the L-shaped lever 49 in the groove provided in the roll paper support plate 47. In such a configuration, when the roll paper 11 ends and the core 57 is dragged by the roll paper, and the bearing member 46 moves up the slope of the groove against the holding force of the L-shaped lever 49, the L-shaped lever 49 rotates in the direction of the arrow around the rotation shaft 49a. When one end of the L-shaped lever 49 kicks the claw of the photointerrupter type sensor 50, a signal is output to the control system to notify the movement of the core 57. Here, the operation when the roll paper ends during the paper feeding will be described. FIG. 7 is a block diagram showing a roll paper end determination method by the control system. As described above, when the winding thickness of the roll paper becomes thin during paper feeding and the distance δ (thickness of the roll paper) between the outer diameter of the remaining roll paper and the outer diameter of the core 57 becomes 8 mm or less, the control system is not controlled. Notification that the remaining amount of roll paper is insufficient. Thereafter, when the paper is further pulled out and the roll paper ends, the core 57 is dragged in the paper transport direction by the paper pulling force of the feed roller 22. As a result, as described above with reference to FIG. 6, the bearing member 46 of the core 57 climbs the slope of the roll paper support plate 47, and the L-shaped lever 4
9 kicks the photointerrupter-type sensor 50 with a nail, and the movement of the core 57 is notified to the control system. In the control system, as shown in FIG. 7, the end of the roll paper is determined only when both the insufficient amount of the roll paper and the movement of the core 57 are detected. Therefore, due to intermittent paper conveyance or the like, a force exceeding the holding force of the L-shaped lever 49 is applied to the core 57 and the roll paper main body moves in the paper feeding direction. Is not determined. Therefore, even if the movement of the main body of the roll paper in the paper feeding direction is erroneously detected, the end of the roll paper is not determined based on this. FIG. 8A shows the rotary cutter 25.
FIG. 2B is a sectional view of the rotary cutter 25.
FIG. The rotary cutter 25 is a rotary blade 2
51, and a fixed blade 252 biased in the direction of the rotary blade 251 by a spring 69. The rotary blade 251 is rotatably supported at both ends by a pair of side plates 62a and 62b. The two ends are connected to a pair of side plates 62a, 6a.
2b, the spring 69 is pivotally supported so as to be able to swing by the elasticity. The pair of side plates 62a, 62b
Constitutes the support frame 60 together with the pair of reinforcing members 61a and 61b. The support frame 60 is accommodated in a bat-shaped cutter support frame 70 which has been subjected to sheet metal processing. Cutter support frame 7
0, three bosses 71a, 71b, 71c and two positioning pins 72a, 72b are erected, and the pair of side plates 62a, 62b of the support frame 60 are
Openings 64a, 64b, 64c at positions opposed to the three bosses 71a, 71b, 71c, and openings 65a, 65b at positions opposed to the two positioning pins 72a, 72b.
Are provided respectively. In the present embodiment, the boss 71 is formed of a welding nut, but may be formed by drawing the support frame 70. To fix the support frame 60 to the cutter support frame 70, first, the positioning pins 72a, 72b are inserted into the openings 65a, 65b to relatively position them, and then the side plates 62a, 62b Opening 64a provided in
64b and 64c from the boss 71a, 71
b, 71c. In this embodiment, one end of the support frame 70 is a fixed end, and is fixed to an apparatus frame or the like (not shown) by two screws 73, while two guide pins 32 are provided at the other end. Are arranged in the up-down direction, and are vertically movable with respect to a long hole provided in an apparatus frame or the like. For this reason, the perpendicularity of the support frame 70 to the roll paper feeding direction during assembly can be adjusted. In the rotary cutter having the above configuration,
Support frame 60 that supports rotating blade 251 and fixed blade 252
Are fixed to the support frame 70 only in the three small areas on the upper surface of the bosses 71a, 71b, 71c. Here, since only one plane passes through any three points in the space, "twist" or "distortion" occurs in the support frame 70, and the relative positions of the respective fixed points, ie, the upper surfaces of the bosses 71a, 71b, and 71c. Even if a misalignment occurs, the support frame 60 is fixed on a new plane uniquely determined by the bosses 71a, 71b, 71c after the positional relationship has shifted, so that the support frame 60 is twisted by the support frame 70. And even if "distortion" occurs, this is
Will not be transmitted to Generally, in the rotary cutter, as long as the relative positional relationship between the rotary blade 251 and the fixed blade 252 is strictly defined, a slight shift in the relative position of the rotary cutter itself with respect to the recording paper is sharp. Has little effect. Therefore, according to the configuration of the present embodiment described above, even if “twist” or “distortion” occurs in the support frame 70 (including the device frame), the relative positional relationship between the rotary blade 251 and the fixed blade 252 is maintained. Since it is always kept constant, it is possible to cut from thin paper to thick paper stably and at high speed. As described above, according to the present invention, even if "twist" or "distortion" occurs in a support frame or a device frame to which the rotary cutter is fixed, the rotary blade of the rotary cutter can be used. Since the relative positional relationship with the fixed blade is always kept constant, it is possible to cut from thin paper to thick paper at high speed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a large-sized printer to which the present invention is applied. FIG. 2 is a perspective view in a state where a roll paper feeding device is pulled out. FIG. 3 is a side sectional view of FIG. 1; FIG. 4 is a cross-sectional view of the roll paper feeding device. FIG. 5 is a diagram specifically showing a configuration of a region surrounded by a broken line A in FIG. FIG. 6 is a diagram showing a configuration in which a core of roll paper is supported at both ends. FIG. 7 is a block diagram showing functions of a control system. FIG. 8 is a configuration diagram of a rotary cutter. [Description of Signs] 1 ... Image forming apparatus, 3 ... Roll paper feeder, 4, 5 ... Cut paper feeder, 6 ... Manual paper feeder, 7 ... Recording paper discharge tray, 8 ... Display unit, 11 ... Roll paper, 22: delivery roller, 25: rotary cutter, 26: photosensitive drum, 30: cut paper, 57: core, 60: support frame, 70
... Cutter support frame, 71a, 71b, 71c ... Boss, 7
2a, 72b: positioning pin, 251: rotary blade, 252
… Fixed blade

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-213295 (JP, A) JP-A-5-86498 (JP, U) JP-A-6-23755 (JP, U) 24055 (JP, B2) Jiko Hira 6-252704 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B26D 1/38 B65H 35/06 G03G 15/00

Claims (1)

(1) In a roll paper feeder provided with a rotary cutter for cutting roll paper according to the size of document information, the rotary cutter comprises a pair of rotary blades and a fixed blade. When, the rotary blade and the fixed blade, and a support frame for rotatably supporting and maintaining the relative positions of both the predetermined relationship, and a fixed object for fixing the support frame, said support frame and said fixed object Contact only in three small areas
And fixed on a plane uniquely determined by the three small areas.
Roll paper feeding apparatus characterized by being constant.