JP2006027780A - Paper feeding mechanism and paper feeding method of printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To contribute to an increase in the quality of printing and enable the easy printing with less number of additional parts and at low cost by eliminating or remarkably reducing such defects that the blanks of a printing paper printed on one side is stained uselessly. <P>SOLUTION: This paper feeding mechanism of a printing device comprises a roller displacement means 7 displacing a pickup roller 3 to a set position Xs where the pickup roller comes into contact with the upper surface of the printing paper P or a release position Xr where the pickup roller is separated from the upper surface of the printing paper P, a detection means 8 detecting that the printing paper P sent out by the pickup roller 3 is moved to a position to which the printing paper P is sent out by a feed roller 4, and a control means 9 displacing the pickup roller 3 to the release position Xr by controlling the roller displacement means 7 by detection of the detection means 8 and, after paper feeding of the printing paper fed by the feed roller 4 is completed, displacing the pickup roller 3 to a set position Xs by controlling the roller displacement means 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a paper feed mechanism and a paper feed method of a printing apparatus including a paper feed roller mechanism that feeds print sheets stacked on a paper feed tray one by one.

  Conventionally, printing apparatuses that perform printing of business cards, postcards, and the like are known, and the present applicant has already proposed a printing apparatus suitable for such applications in Japanese Patent Laid-Open No. 2003-128278.

By the way, this type of printing apparatus is usually provided with a paper feed mechanism having a paper feed roller mechanism that feeds the print sheets stacked on the paper feed tray one by one. A pickup roller abutting on the uppermost surface of a large number of printed materials, a feed roller disposed in front of the pickup roller in the conveying direction, and a retard roller disposed below the feed roller. The paper feed roller mechanism that feeds the prints one by one by rotating the printhead, and the weight applied from above to the prints on the feed tray from the pickup roller is changed according to the type of prints A paper feeding mechanism of a printing apparatus provided with the mechanism is disclosed. According to this paper feed mechanism, there are problems that occur when the paper is an envelope, that is, a plurality of papers are overlapped, there is a step due to sticking, a bag shape that easily generates an air layer, etc. The problem that occurs with envelopes that cannot be fed smoothly and stably during paper feeding is effectively eliminated, and even with envelopes, pickup errors do not occur smoothly and stably. Sheet feeding is realized.
JP 2003-128278 A

  However, the above-described conventional paper feeding mechanism of the printing apparatus solves the problem that occurs when the printing paper is an envelope, and cannot cope with a problem that occurs when the size of the printing paper is large or when duplex printing is performed. There was a further problem to be solved.

  That is, when performing double-sided printing, the printed paper on the back side is stacked on the paper feed tray. Therefore, when the paper is fed by the pickup roller, the space between the printing paper fed by the pickup roller and the lower printing paper is As a result, there is a problem that the printed color of the printed surface on the back side of the printing paper to be sent is transferred to the white background on the lower printing paper, and the white background is soiled. The bigger it is, the bigger it becomes. Note that this problem is practically a slight and negligible stain, or it may occur due to the use environment, etc. Therefore, it is desirable to take necessary measures from the viewpoint of always ensuring a high-quality printing surface.

  An object of the present invention is to provide a paper feeding mechanism and a paper feeding method for a printing apparatus that solve the problems in the background art.

  In order to solve the above-described problem, the paper feed mechanism 1 of the printing apparatus M according to the present invention has a pickup roller 3 that contacts the upper surface of the printing paper P stacked on the paper feed tray 2 and the conveyance of the pickup roller 3. A feed roller having a feed roller 4 disposed in front of the direction Fc and a retard roller 5 disposed below the feed roller 4 and rotating the pickup roller 3 and the feed roller 4 to feed the printing paper P one by one. A paper feed mechanism having a mechanism 6, a roller displacing means 7 for displacing the pickup roller 3 to a set position Xs contacting the upper surface of the print paper P or a release position Xr spaced from the upper surface of the print paper P; Detecting means 8 for detecting that the printing paper P delivered by 3 has moved to a position delivered by the feed roller 4; At least, the roller displacing means 7 is controlled by detection by the detecting means 8 to displace the pickup roller 3 to the release position Xr, and the roller displacing means 7 is controlled when the feeding of the printing paper P delivered by the feed roller 4 is completed. And a control means 9 for displacing the pickup roller 3 to the set position Xs. In this case, according to a preferred aspect of the present invention, the roller displacing means 7 can be a drive solenoid 11 that displaces the pickup roller 3 supported so as to be movable up and down to at least one of the release position Xr and the set position Xs. .

  Further, in order to solve the above-described problem, the paper feeding method of the printing apparatus M according to the present invention includes a pickup roller 3 that contacts the upper surface of the printing paper P stacked on the paper feeding tray 2, and the pickup roller 3. When feeding the printing paper P one by one by rotating the pickup roller 3 and the feed roller 4 having a feed roller 4 disposed in front of the conveyance direction Fc and a retard roller 5 disposed below the feed roller 4, If the pickup roller 3 is brought into contact with the upper surface of the printing paper P and the printing paper P is sent out by the rotation of the pickup roller 3 and the sent printing paper P is moved to a position where it is sent out by the feed roller 4, the pickup roller 3. Is separated from the upper surface of the printing paper P and the printing paper P sent out by the feed roller 4 is Wherein the paper has to be brought into contact with the upper surface of the printing paper P to the pickup roller 3 has finished. In this case, according to a preferred aspect of the invention, the printing paper P is preferably a printing paper on which one side has been printed.

  According to the sheet feeding mechanism 1 and the sheet feeding method of the printing apparatus M according to the present invention, the following remarkable effects can be obtained.

  (1) Since the rubbing between the printing papers P when the printing paper P is fed out by the pickup roller 3 can be greatly reduced, in particular, the problem that one side of the printing paper P that has already been printed is unnecessarily soiled. This can be eliminated or greatly reduced, and can contribute to the improvement of print quality.

  (2) In addition to being able to be implemented easily and at low cost with a small number of additional parts, the pickup roller 3 supported by the roller displacing means 7 so as to be movable up and down is at least set to the release position Xr or set according to a preferred embodiment. If the drive solenoid 11 that is displaced to one of the positions Xs is used, it is possible to contribute to further ease of implementation and cost reduction.

  Next, the best embodiment according to the present invention will be given and described in detail with reference to the drawings.

  First, in order to facilitate understanding of the present invention, an overview of the entire printing apparatus M will be described with reference to FIGS.

  FIG. 5 shows an external configuration of the printing apparatus M. The printing apparatus M roughly includes a paper feeding unit U1, a transport unit U2, a color printing unit U3, and a paper discharge unit U4. Reference numeral 65 denotes an operation unit. This printing apparatus M can be used particularly for business purposes, and a large amount and a wide range of sizes can be used for the printing paper P ... such as business card printing to poster printing.

  FIG. 6 shows a schematic configuration of a mechanical system in the printing apparatus M, and the positional relationship corresponds to the external configuration of the printing apparatus M shown in FIG. The paper feed unit U1 incorporates the paper feed mechanism 1 according to the present embodiment. The sheet feeding mechanism 1 is composed of a sheet feeding tray 2 on which a large amount of printing sheets P... Can be set, a sheet feeding elevator mechanism 71 for raising and lowering the sheet feeding tray 2, and a sheet of printing sheets P on the sheet feeding tray 2. A paper feed roller mechanism 6 for feeding the printing paper P one by one is provided. In this case, the paper feed elevator mechanism 71 includes a face control sensor (not shown) that detects the top surface position of the printing paper P stacked on the paper feed tray 2, and if the top surface position is lowered, the paper feed elevator mechanism 71 is fed. The paper elevator mechanism 71 is driven and controlled, and the top surface position is always maintained at a fixed position. The paper feed roller mechanism 6 constitutes a main part of the present invention, and a specific configuration and operation will be described later.

  The transport unit U2 includes a plurality of transport rollers 72, and has a function of transporting the printing paper P fed from the paper feed roller mechanism 6 to the color printing unit U3. In this case, the interval between the conveying rollers 72 is set to be shorter than the minimum size of the printing paper P to be conveyed. In addition, the transport unit U2 includes various correction functions such as a skew correction function that uniformly aligns the angle (orientation) of the printing paper P to be transported.

  The color printing unit U3 includes a developing unit 73, a transfer unit 74, and a fixing unit 75 as main components. In this case, the developing unit 73 has a function of forming an electrostatic image on a semiconductor drum (photoconductor) based on print image data transferred from a computer C, which will be described later, and attaching color toner to the electrostatic image. And a Y (yellow) developing unit 73y, an M (magenta) developing unit 73m, a C (cyan) developing unit 73c, and a Bk (black) developing unit 73bk. Further, the transfer unit 74 has a function of transferring the toner image obtained by the developing unit 73 to the conveyed printing paper P. Further, the fixing unit 75 has a function of fixing (fixing) the toner image transferred to the printing paper P by the transfer unit 74 to the printing paper P by heating and pressing.

  The paper discharge unit U4 includes a discharge roller 76 and a stacker mechanism 77. The stacker mechanism 77 receives the print sheets P ... discharged from the discharge roller 76 and descends sequentially according to the weight of the stacked print sheets P .... The paper discharge unit U4 is provided with a cooling mechanism 78, and the heated print paper P is cooled (air-cooled) by blowing air to the print paper P discharged from the discharge roller 76.

  The printing apparatus M is used by connecting to a computer. FIG. 7 shows a printing system S in which a printing apparatus M and a computer C are connected. In this case, the interface 51 of the printing apparatus M and the interface 52 of the computer C are connected by the connecting means 53. The interfaces 51 and 52 may be a parallel method or a serial method. Further, the connection means 53 may be a wired system or a wireless system. The printing apparatus M includes a main part including a print controller 54, a memory 55, and the like. In the printing apparatus M, printing is performed under the control of the print controller 54. On the other hand, the computer C can be a general-purpose personal computer including main parts such as a processing unit 57 including a CPU and the like, and a memory 58 including a hard disk, a ROM, a RAM, and the like. In particular, the computer C includes a printer driver 60 installed by application software, and various printing conditions for operating the printing apparatus M are set by the printer driver 60, and print image data is transferred from the computer C to the printing apparatus M. Is done. The computer C and the printing apparatus M can perform two-way communication, and printing under the control of the computer C is also possible.

  Next, a specific configuration of the paper feed mechanism 1 according to the present embodiment will be described with reference to FIGS. 1 and 2.

  The paper feed mechanism 1 includes the above-described paper feed roller mechanism 6. The paper feed roller mechanism 6 includes a pickup roller 3 that abuts on the upper surface of the printing paper P stacked on the paper feed tray 2, and the pickup roller 3. A feed roller 4 disposed in front of the feed direction Fc and a retard roller 5 disposed below the feed roller 4. The pickup roller 3 and the feed roller 4 are rotated to feed the printing paper P, and the feed roller 4 and the retard roller 5 have a function of separating the printing paper P one by one and feeding it forward.

  The pickup roller 3 is rotatably supported by a rear portion of a bracket 22 whose front portion is rotatably supported by the shaft 21 of the feed roller 4. As a result, the pickup roller 3 can be pivoted up and down with the shaft 21 as a fulcrum. Further, in FIG. 1, the fixed intermediate chassis 23 indicated by a broken line is provided with a vertical opening 24 indicated by a virtual line, and one end of the shaft 25 of the pickup roller 3 further extends outward in the axial direction. The engaging portion 25 s is formed to protrude outward of the intermediate chassis 23 through the opening 24. Thereby, the vertical displacement of the engaging portion 25 s is allowed by the opening 24.

  The drive solenoid 11 is attached to the outer surface of the intermediate chassis 23. The drive solenoid 11 is pulled into the plunger 11p by energization (excitation) and displaced to the lowered position shown in FIG. 2, and the plunger 11p protrudes by the release of energization (excitation) and is displaced to the raised position shown in FIG. Further, a lever member 26 formed in a T shape is provided, and one end portion of the horizontal portion 26 h of the lever member 26 is rotatably supported by a support shaft portion 27 fixed to the outer surface of the intermediate chassis 23. At this time, the other end portion of the horizontal portion 26h is positioned below the engaging portion 25s, and a notch engaging portion 28 is formed at the lower end portion of the vertical portion 26v, and this notch engaging portion 28 is connected to the plunger 11p. It engages with an engagement pin 29 provided at the tip of the. Further, a coil spring 30 is attached to the support shaft portion 27, and the other end portion of the horizontal portion 26h of the lever member 26 is biased upward.

  As described above, in the state where the roller displacing means 7 is configured and the drive solenoid 11 is de-energized (excited), the plunger 11p protrudes, so that the horizontal portion 26h of the lever member 26 biased by the coil spring 30 is Then, it is pivotally displaced counterclockwise with the support shaft portion 27 as a fulcrum. As a result, as shown in FIG. 1, the other end portion of the horizontal portion 26h of the lever member 26 is locked from the lower side with respect to the engaging portion 25s, and the engaging portion 25s is displaced upward, that is, a pickup roller. 3 is displaced to a release position Xr that is separated from the upper surface of the printing paper P. On the other hand, in a state where the drive solenoid 11 is energized (excited), the plunger 11p is drawn, so that the vertical portion 26v of the lever member 26 is lowered by the plunger 11p, and the horizontal portion 26h of the lever member 26 is a support shaft. The portion 27 is pivotally displaced clockwise with the fulcrum 27 as a fulcrum. As a result, the other end portion of the horizontal portion 26h of the lever member 26 is displaced to the lowered position as shown in FIG. 2, so that the engagement with the engaging portion 25s is released, and the pickup roller 3 is lowered by its own weight. Then, it is displaced to a set position Xs that contacts the upper surface of the printing paper P.

  The feed roller 4 is rotationally driven by a roller drive mechanism (not shown), and the pickup roller 3 rotates integrally (synchronously rotates) with the feed roller 4 via a rotation transmission gear mechanism (not shown). The roller drive mechanism that rotationally drives the feed roller 4 is controlled by the print controller 54. Thus, since the pickup roller 3 supported so as to be movable up and down is used as the roller displacing means 7 by using the drive solenoid 11 that displaces at least one of the release position Xr and the set position Xs, the implementation is easy and low. There is an advantage that can contribute to cost reduction.

  On the other hand, a detecting means 8 for detecting that the printing paper P sent out by the pickup roller 3 has moved to a position sent out by the feed roller 4 is provided. As the detection means 8, a detection switch 35 having a detection lever 35r as shown in FIG. 2 can be used. In the non-detection state, the detection switch 35 is turned OFF when the detection lever 35r is displaced upward as shown in FIG. 2, and when the print paper P passes, as shown in FIG. Is pushed downward to turn on. In this case, it is desirable to set the position at which the detection switch 35 is disposed so that the timing immediately after the printing paper P enters between the feed roller 4 and the retard roller 5 can be detected.

  Further, when the detection switch 35 is turned on, the drive solenoid 11 is controlled to displace the pickup roller 3 to the release position Xr, and when the feeding of the printing paper P delivered by the feed roller 4 is finished, the drive solenoid 11 is controlled. Control means 9 for displacing the pickup roller 3 to the set position Xs is provided. The control means 9 is used by the print controller 54 described above. For this reason, the drive solenoid 11 is connected to the output side of the print controller 54 and the detection switch 35 is connected to the input side of the print controller 54.

  Next, the operation of the paper feed mechanism 1 including the paper feed method according to the present embodiment will be described according to the flowchart shown in FIG.

  First, the printing paper P is set on the paper feed tray 2. The printing paper P is a printing paper on which one side has been printed. Note that the paper feeding method according to the present embodiment is particularly effective when used on the printing paper P ... on which one side is printed, so that only when printing the printing paper P ... on which one side is printed by mode selection, The sheet feeding method according to the present embodiment can be selected to be executed. In this case, the printer driver 60 in the computer C can be activated and a mode can be selected from the property screen displayed on the display.

  On the other hand, when the start key on the property screen is turned ON, the setting data and the print image data are transferred from the computer C to the printing apparatus M and stored in the memory 55. When the printing device M is ready for printing, the paper feed roller mechanism 6 is activated, and the printing paper P loaded on the paper feed tray 2 is fed forward by the pickup roller 3 (steps S1 and S2). . Therefore, when the paper feed roller mechanism 6 operates, the drive solenoid 11 is energized (excited) and the pickup roller 3 is in the set position Xs shown in FIG. This state is shown in FIG.

  When the printing paper P moves forward and moves to a position where it is fed out by the feed roller 4, the detection switch 35 is turned on to detect the leading edge of the printing paper P, so that the print controller 54 immediately drives. Control to cancel energization (excitation) of the solenoid 11 is performed (steps S3 and S4). As a result, the lever member 26 is displaced upward and the engaging portion 25s is lifted to displace the pickup roller 3 to the release position Xr that is separated from the upper surface of the printing paper P (step S5). This state is shown in FIG. Therefore, the pressure applied to the printing paper P by the pickup roller 3 is released, so that the rubbing between the printing papers P is avoided. That is, the occurrence of rubbing between the printing papers P due to the pressurization of the pickup roller 3 is only a small section Ls from when the pickup roller 3 starts to rotate until the printing paper P reaches the feed roller 4. ... the friction between each other is greatly reduced, and in particular, the problem of unnecessarily soiling the white background of the printing paper P ... on which one side has been printed can be eliminated or greatly reduced. FIG. 4C shows a state in which the printing paper P is sent out only by the feed roller 4.

  Further, when the printing paper P is sent out only by the feed roller 4 and the feeding of the printing paper P is completed, the operation of the paper feeding roller mechanism 6 is stopped (steps S6, S7, S8). In this case, the end of feeding of the printing paper P can be detected based on the fact that the trailing edge of the printing paper P passes the detection switch 35 and the detection switch 35 is turned off. For example, after the detection switch 35 is turned off. After a predetermined set time (margin time) has elapsed, the operation of the paper feed roller mechanism 6 can be stopped. Then, simultaneously with or after the stop of the operation of the paper feed roller mechanism 6, the drive solenoid 11 is energized (excited) (step S9). As a result, the pickup roller 3 is displaced to the set position Xs in contact with the upper surface of the printing paper P. Thereafter, the same operation is performed for feeding the next printing paper P (steps S10, S1,...).

  Although the best embodiment has been described in detail above, the present invention is not limited to such an embodiment, and departs from the gist of the present invention in the detailed configuration, shape, material, quantity, numerical value, and the like. It can be changed, added, or deleted as long as it is not.

  For example, the case where the drive solenoid 11 that is displaced to the set position Xs and the spring 30 that is displaced to the release position Xr are used as the roller displacing means 7, but the set position is set by the bidirectional drive type drive solenoid without using the spring 30. It may be displaced to Xs and release position Xr, or other drive means such as a drive motor may be used instead of the drive solenoid. Moreover, although the case where the detection switch 35 was used as the detection means 8 was shown, other detection means 8 such as an optical sensor may be used. Furthermore, although the case where the print controller 54 is used as the control means 9 is shown, a simple sequence circuit that can control the roller displacement means 7 in accordance with the detection result of the detection means 8 without using the print controller 54 is shown. It may be provided separately.

The side surface block diagram of the state which displaced the pick-up roller in the paper feeding mechanism which concerns on the best embodiment of this invention to the release position, Side view of the state in which the pickup roller in the paper feed mechanism is displaced to the set position, A flowchart for explaining the operation of the paper feed mechanism including the paper feed method according to the present embodiment; Operation explanatory diagram of the paper feeding mechanism, External perspective view of a printing apparatus provided with the paper feeding mechanism, Schematic configuration diagram of the mechanical system in the printing apparatus, Block diagram of a printing system that connects the printing device and a computer,

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed mechanism 2 Paper feed tray 3 Pickup roller 4 Feed roller 5 Retard roller 6 Feed roller mechanism 7 Roller displacement means 8 Detection means 9 Control means 11 Drive solenoid M Printing device P ... Printing paper Fc Conveyance direction Xs Set position Xr Release position

Claims (4)

  A pickup roller abutting on the upper surface of the printing paper stacked on the paper feed tray; a feed roller disposed in front of the pickup roller in the transport direction; and a retard roller disposed below the feed roller, the pickup roller And a feed roller mechanism that feeds the print paper one by one by rotating the feed roller, in the paper feed mechanism of the printing apparatus, the pick-up roller contacts the upper surface of the print paper or the upper surface of the print paper A roller displacing means for displacing to a release position that is separated from the detecting position; a detecting means for detecting that the printing paper fed by the pickup roller has moved to a position fed by the feed roller; and at least by detection of the detecting means The pick-up is controlled by controlling the roller displacement means. And a controller for displacing the roller to the release position and controlling the roller displacing means to displace the pickup roller to the set position when feeding of the printing paper fed by the feed roller is completed. A feeding mechanism of a printing apparatus.   The sheet feeding mechanism of the printing apparatus, wherein the roller displacing unit includes a drive solenoid that displaces the pickup roller supported so as to be movable up and down to at least one of a release position and a set position.   A pickup roller abutting on the upper surface of the printing paper stacked on the paper feed tray; a feed roller disposed in front of the pickup roller in the transport direction; and a retard roller disposed below the feed roller, the pickup roller And feeding the print paper one by one by rotating the feed roller, the pickup roller is brought into contact with the upper surface of the print paper, and the print paper is fed out by rotation of the pickup roller. If the sent printing paper has moved to the position fed by the feed roller, the pickup roller is moved away from the upper surface of the printing paper, and the feeding to the printing paper fed by the feed roller is completed. Pickup roller for the printing Paper of the printing apparatus, characterized in that to abut the to the top surface.   4. The paper feeding method for a printing apparatus according to claim 3, wherein the printing paper is a printing paper on which one side has been printed.

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