JP3674971B2 - Inkjet printing and recording device - Google Patents

Description

[0001]
[Industrial application fields]
  The present invention relates to an ink jet printing recording apparatus in which a drive motor is shared by a paper feed system and a head recovery system, and in particular, a drive transmission to a head recovery system is disconnected and a print head passes through a printing medium. The present invention relates to an ink jet printing recording apparatus in which paper feeding operation and paper ejection operation by a paper feeding system is performed only when it is at an outside position, thereby preventing adverse effects such as breakage of the print head.
[0002]
[Prior art]
  2. Description of the Related Art Conventionally, a printing recording apparatus that records a dot pattern image on a printing medium such as paper or a plastic sheet based on transferred printing information, such as a copying machine, a facsimile machine, a personal computer printer, and the like has been used. As one type of print head mounted on the print portion of these printing recording apparatuses, there is an ink jet print head that performs printing by ejecting and ejecting small droplets of ink from an ejection port and adhering them to paper or the like to be printed. .
[0003]
  In such an ink jet print head, bubbles may be generated in the ink inside the print head during use, resulting in poor ink ejection. Therefore, it is necessary to periodically perform cleaning to remove the cause of the defect and restore the good discharge port state. For this reason, a purge pump driven by a motor is provided, and a purge operation for sucking out defective ink from the discharge surface of the print head by the negative pressure generated by the purge pump is periodically performed.
  Although it is conceivable to provide a dedicated motor for driving the purge pump, it is common to use a drive motor for the platen roller for paper feeding, and it is configured to change which one is driven by switching the connecting gear. Many. This is because the motor is heavy, so if the number of motors is large, the weight and size of the entire printing and recording apparatus are affected.
[0004]
  As a conventional example in which the drive motor is shared by the drive of the purge pump and the paper feed, there is one disclosed in Japanese Patent Laid-Open No. 62-263058. In the ink jet printer disclosed in the publication, the print head recovery mechanism is configured such that the gear of the drive transmission system is slid only when the carriage is in the recovery position where the recovery operation is received by the rotation lever that is linked to the movement of the carriage on which the print head is mounted. The drive is transmitted to. When the drive transmission system is connected to the recovery mechanism side, paper feeding is not performed.
[0005]
  The reason is to prevent the reverse drive from being transmitted to the print head recovery mechanism. When the purge pump of the print head recovery mechanism receives a reverse drive, a positive pressure is generated in reverse to the normal operation, so that the defective ink that has been sucked in from the discharge surface of the print head and collected in the recovery mechanism in the recovery operation so far is collected. It is because it will be ejected.
  On the other hand, when feeding paper, the drive motor needs to rotate not only forward but also in reverse to align the leading edge of the printing paper or to remove excess printing paper when multiple papers are fed. When such reverse rotation is transmitted to the print head recovery mechanism, a reverse flow of ink from the recovery mechanism to the print head occurs, the head is damaged, or ink is scattered from the recovery mechanism to the surroundings, resulting in significant dirt. Become. In order to prevent such an adverse effect, the drive connection to the recovery mechanism side is disconnected except when the recovery operation is performed.
[0006]
[Problems to be solved by the invention]
  However, the conventional ink jet printing recording apparatus has the following problems. That is, although the reverse rotation of the purge pump of the print head recovery mechanism is prevented, no consideration is given to the positional relationship between the print head and the print head newly supplied to the platen roller. Therefore, even when the print head is positioned within the range through which the printing paper on the platen roller passes, the paper feeding mechanism may be driven for paper feeding. For this reason, as shown in FIG. 9, the ejection surface of the print head 10 may be attacked and damaged by the leading edge of the printing paper S. This is because the front end of the printing paper S is not tensioned and may slightly float from the platen roller 6, while the discharge surface of the print head 10 is not very strong. In some cases, the printing paper S is stained with ink.
[0007]
  Further, when the printed paper S is discharged from the platen roller 6, the discharge surface of the print head 10 may be attacked by the end of the printing paper S to cause the same problem.
[0008]
  The present invention has been made to solve the above-mentioned conventional problems. The drive transmission to the head recovery system is connected only when the print head recovery operation is performed by the head recovery system, and the print head is covered. The paper feed system and the paper discharge operation are performed only when the print body is out of the range where the printed material passes. An object of the present invention is to provide an ink jet printing recording apparatus that can share a drive motor with a system.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, an ink jet printing recording apparatus (1) of the present invention comprises:A print head for ejecting ink onto the print paper; a transport roller for feeding the print paper to the print head; A carriage that is movable in the axial direction of the transport roller, a recovery unit that recovers the print head, a switching mechanism that drives either the recovery unit or the transport roller, and the switching mechanism via the switching mechanism. A recovery motor or a drive motor that drives the transport roller, and the switching mechanism is an idle that is slidable between a platen gear that drives the transport roller, a purge gear that drives the recovery means, and the platen gear and the purge gear. A gear, a first urging member that urges the idle gear to move in the purge gear direction, and a regulating member that regulates movement of the idle gear in the purge gear direction by the first urging member, When the carriage moves to a recovery position where the print head receives a recovery operation by the recovery means, the carriage moves forward. The regulating member is moved to the non-operating position to release the regulation of the idle gear, the idle gear is biased in a connectable position and the purge gear by said first biasing memberIt is set as the characteristic characterized by this.
[0010]
  Further, the ink jet printing recording apparatus (2) of the present invention isThe idle gear includes an outer peripheral surface of the purge gear, a mesh tooth meshed with the outer peripheral surface of the platen gear, and a mesh tooth meshed with an outer peripheral surface of the drive gear for transmitting the drive motor, Slides in mesh with the drive gear and meshes with either the purge gear or the platen gearIt is set as the structure of (1) characterized by this.
  Moreover, the ink jet printing recording apparatus (3) of the present invention isThe restriction member includes an idle kicker that abuts on an axial end surface portion of the idle gear, and a second biasing member that biases the idle kicker to move the idle gear in the platen gear direction, The biasing force of the second biasing member is greater than the biasing force of the first biasing member.It is set as the structure of (1) or (2) characterized by the above.
[0011]
[Action]
  In the ink jet printing recording apparatus (1) of the present invention having the above configuration,The driving force of the drive motor is transmitted to either the recovery means or the transport roller via the switching mechanism. The switching mechanism includes a platen gear that drives the transport roller, a purge gear that drives the recovery means, an idle gear that can slide between the platen gear and the purge gear, and a first bias that moves the idle gear in the purge gear direction. The urging member and a restricting member for restricting the movement of the idle gear in the purge gear direction by the first urging member are configured, and the idle gear is engaged with the platen gear by the restriction by the restricting member. When the carriage moves to the recovery position where the print head receives the recovery operation by the recovery means, the carriage moves the restricting member to the non-functional position for releasing the restriction on the idle gear, and the idle gear is moved to the first biasing member. Is biased to a position connectable to the purge gear. Thus, when the carriage moves to the recovery position, the driving force of the drive motor is transmitted to the recovery means, and the print head is recovered.
[0012]
  In the ink jet printing recording apparatus (2) of the present invention,The idle gear slides while meshing with the outer peripheral surface of the drive gear, and meshes with either the outer peripheral surface of the purge gear or the platen gear.
  In the ink jet printing recording apparatus (3) of the present invention,The idle gear is regulated so as to move in the platen gear direction by an idle kicker biased by a second biasing member having a biasing force larger than that of the first biasing member.
[0013]
【Example】
  Hereinafter, an ink jet printing recording apparatus according to the present invention will be described in detail with reference to the drawings based on an embodiment in which the present invention is embodied as an ink jet printer connected to a personal computer.
  First, the configuration of the ink jet printer according to this embodiment will be described with reference to FIGS.
  FIG. 1 is a perspective view of an ink jet printer. In FIG. 1, a manual paper feed unit 3 is provided at the front of the main body frame 2 of the inkjet printer 1, and a print head 10 and a recovery mechanism, which will be described later, are located behind the manual paper feed unit 3 and above the main body frame 2. A sub-frame 4 incorporating the RM and the paper feed mechanism LM is placed. A paper feed cassette 5 for storing a plurality of printing papers is detachably attached to the upper rear side of the subframe 4.
[0014]
  FIG. 2 is a perspective view of the subframe 4 of the ink jet printer 1 and the print head 10 built in the subframe 4, the recovery mechanism RM, the paper feed mechanism LM, and the like. In FIG. 2, a cylindrical platen roller 6 is disposed in the rear side of the subframe 4. The platen roller 6 conveys the printing paper supplied from the paper feeding cassette 5 or the manual paper feeding unit 3 while facing the print head 10, and forms part of the paper feeding mechanism LM. On the upper side of the platen roller 6, a pressure roller 8 is provided for bringing the printing paper into close contact with the platen roller 6. The platen roller 6 is driven via the platen gear 7 by an LF motor 29 that does not appear in FIG. The platen gear 7 also transmits drive to a paper feed gear train (described later) for feeding printing paper from the paper feed cassette 5 to the single platen roller 6.
[0015]
  A carriage 9 is provided in front of the platen roller 6. The carriage 9 is equipped with an ink jet print head 10 and is movable along a carriage shaft 11 provided in parallel with the platen roller 6. This is because the print head 10 is moved along the platen roller 6. A CR motor 12 for driving the carriage 9 is disposed on the right rear surface of the subframe 4. The CR motor 12 drives the carriage 9 via the belt 13, and uses a step motor or a DC motor. A tape-like position gauge 14 is provided along the belt 13. The position gauge 14 is provided with a scale.
[0016]
  A recovery mechanism RM for the print head 10 is disposed on the left side of the platen roller 6. The ink jet print head 10 causes a discharge failure due to bubbles generated inside during use or ink droplets adhering to the discharge surface, and this is recovered to a good discharge state. Because. A purge device 18 or the like is provided as the recovery mechanism RM.
  A cap 15 is provided at the tip of the purge device 18. The purge device 18 generates a negative pressure with a known pump when the print head 10 is covered with the cap 15, and sucks and recovers defective ink inside the print head 10. The pump of the purge device 18 is driven by an LF motor 29 through a pump cam gear 19.
[0017]
  Here, the relationship between the movement range of the carriage 9, the position covered by the cap 15 of the purge device 18, and the range through which the printing paper on the platen roller 6 passes will be described with reference to FIG. In FIG. 3, the position of the carriage 9 is taken on the horizontal axis, the left side in the figure corresponds to the left side in FIG. 2 (the side with the recovery mechanism RM), and the right side in FIG. Side). The movement range m of the carriage 9 is wider than the width w of the platen roller 6, and in particular, on the left side of the width w, a standby position HP of the carriage 9 and a position CP covered by the cap 15 of the purge device 18 are provided. The printing paper passes through the width w. The printing range p from the line head printing position O to the line end printing position Z is within the platen roller width w, and the moving speed of the carriage 9 within this range is a predetermined printing speed.
[0018]
  Next, the control system of the inkjet printer 1 will be described with reference to the block diagram of FIG. This control system is configured around a CPU 20 which is a known arithmetic processing unit. The CPU 20 is connected to the host 22 via the interface 21. The host 22 is a personal computer. That is, the ink jet printer 1 receives a print command from the host 22 and executes various printings according to the command.
[0019]
  A switch panel 23, ROM 24, and RAM 25 are connected to the CPU 20. The switch panel 23 sets and displays the paper size and other various parameters. The ROM 24 stores various programs necessary for controlling the ink jet printer 1. As a typical program stored in the ROM 24, a paper feed program for driving the LF motor 29 to supply printing paper from the paper feed cassette 5 to the platen roller 6, and for discharging printed paper from the platen roller 6 There are a paper discharge program for driving the LF motor 29, a retreat program for retreating the carriage 9 to the standby position HP before paper supply and paper discharge, and the like. The RAM 25 temporarily stores print data transferred from the host 22 and various numerical values necessary for controlling the inkjet printer 1.
[0020]
  The CPU 20 controls driving of the LF motor 29, the CR motor 12, and the print head 10 via the LF driving circuit 26, the CR driving circuit 27, and the head driving circuit 28.
  The LF motor 29 drives either the purge mechanism 32 or the paper feed mechanism LM via the switching mechanism 30. The purge mechanism 32 includes the purge device 18, the pump, the pump cam gear 19, and the like. The paper feed mechanism LM includes the platen roller 6 and the pressure roller 8 described above.
  The CR motor 12 drives the carriage mechanism 31. The carriage mechanism 31 includes the belt 13 and its pulleys in addition to the carriage 9. The switching mechanism 30 is switched by the movement of the carriage 9.
[0021]
  Each of the purge mechanism 32, the paper feed mechanism LM, and the carriage mechanism 31 includes a sensor, and notifies the counter group 36 provided in the CPU 20 of a detection signal.
  The purge mechanism 32 is provided with a purge HP sensor 33. The purge HP sensor 33 notifies the purge position counter of the counter group 36 when the pump is at the origin position. This signal is used as a reference for the purge operation by the purge mechanism 32.
[0022]
  The paper feed mechanism LM is provided with a PE sensor 34. The PE sensor 34 generates a signal by the leading edge of the newly supplied printing paper and notifies the LF position counter of the counter group 36. This signal becomes the reference for the printing position control in the vertical direction.
  The carriage mechanism 31 is provided with a CR position sensor 35. The CR position sensor 35 counts the drive pulses of the CR motor 12 to detect the position of the carriage 9 and informs the CR position counter of the counter group 36. This position information serves as a reference for controlling the printing position in the horizontal direction, and also serves as a reference for determining whether or not a new printing paper supply operation and a printed paper discharge operation are possible.
[0023]
  Next, the switching mechanism 30 will be described. As described above, the switching mechanism 30 switches the transmission destination of the drive of the LF motor 29 between the purge mechanism 32 and the paper feed mechanism LM. FIG. 5 shows a gear group forming the switching mechanism 30. The switching mechanism 30 includes an LF idle gear 41 that can move in the axial direction (arrow A), an idle kicker 43 that moves the LF idle gear 41 in the axial direction, and a compression that biases the LF idle gear 41 leftward in the arrow A direction. And a spring 45. In FIG. 5, each component is drawn separately for easy understanding, but in actuality, each component is arranged closer to the horizontal direction (direction parallel to the arrow A) in the drawing.
[0024]
  The LF idle gear 41 includes a mesh tooth 38 between the LF motor 29 and the coaxial motor gear 37, a mesh tooth 40 between the platen roller 6 and the coaxial platen gear 7, a mesh tooth 39 with the purge gear 42 that transmits drive to the pump cam gear 19, It has three biting teeth. The biting teeth 38 and the motor gear 37 are always meshed. The biting teeth 40 and the platen gear 7, and the biting teeth 39 and the purge gear 42 are alternatively meshed by the movement of the LF idle gear 41 in the axial direction.
[0025]
  The idle kicker 43, together with the kick portion 46 and the spring hook 48, is formed on a kicker shaft 44 that is pivotable about an axis. By the rotation of the kicker shaft 44, either the state indicated by a solid line or the state indicated by a two-dot chain line is taken. A tension spring 47 is hung on the spring hook 48, and the idle kicker 43 and the like are urged by the elastic force of the tension spring 47 to be in a solid line state. The elastic force of the tension spring 47 is stronger than the elastic force of the compression spring 45. Further, the kick portion 46 is provided at a position protruding in the movement range of the carriage 9. When the carriage 9 moves from the standby position HP in FIG. 3 to the purge position CP, the lower portion of the carriage 9 kicks the kick portion 46 to be in a two-dot chain line state.
[0026]
  In normal times, the spring is biased by the elastic force of the pulling spring 47 and is in a solid line position. At this time, the idle kicker 43 pushes the LF idle gear 41 in the right direction of the arrow A against the bias of the compression spring 45. For this reason, the mesh teeth 40 of the LF idle gear 41 mesh with the platen gear 7, and the drive of the LF motor 29 is transmitted to the platen roller 6 and the like. On the other hand, the teeth 39 and the purge gear 42 do not mesh with each other, and the pump cam gear 19 is not driven.
  On the other hand, when the carriage 9 is positioned at the purge position CP, the idle kicker 43 and the like are in a two-dot chain line state, and the bias of the tension spring 47 is released. Only in this case, the LF idle gear 41 is pushed to the left of the arrow A by the urging of the compression spring 45, and the meshing teeth 39 mesh with the purge gear 42. Thus, the drive is transmitted to the pump cam gear 19 and the purge mechanism 32 is driven. At this time, the teeth 40 and the platen gear 7 do not mesh with each other, and the platen roller 6 and the like are not driven.
[0027]
  Next, a paper feed gear train for supplying printing paper from the paper feed cassette 5 to the platen roller 6 will be described with reference to FIGS. The paper feed gear train shown in FIG. 6 includes a first idle gear 49 that meshes with the platen gear 7, a gear frame 50 that is provided coaxially with the first idle gear 49, and a first idle gear 49 that is attached to the gear frame 50. 49, a second idle gear 51 that meshes with 49, and a third idle gear 54, and a separation roller gear 53 that is coaxial with the separation roller just below the sheet feeding cassette 5 and a fourth idle gear 52 that meshes with this. doing.
[0028]
  When the printing paper S already supplied to the platen roller 6 is fed in the forward direction, the forward rotation of the LF motor 29 is transmitted to the platen gear 7 and rotates counterclockwise in the figure. Therefore, the first idle gear 49 meshing with this rotates in the clockwise direction in the figure. The driven gear frame 50 rotates clockwise in the drawing until the second idle gear 51 is engaged with the fourth idle gear 52. Since the second idle gear 51 rotates in the counterclockwise direction in the figure, the fourth idle gear 52 rotates in the clockwise direction in the figure, and the separation roller gear 53 engaged therewith rotates in the counterclockwise direction in the figure. FIG. 6 shows this state.
[0029]
  When supplying a new sheet of printing paper S to the platen roller 6, the LF motor 29 rotates in the reverse direction. This is because the platen gear 7 is rotated in the reverse direction (clockwise in the figure) to align the paper S. For this reason, the first idle gear 49 meshing with this rotates counterclockwise in the figure. The driven gear frame 50 rotates counterclockwise in the drawing until the third idle gear 54 meshes with the separation roller gear 53. Therefore, the third idle gear 54 rotates clockwise in the figure, and the separation roller gear 53 that meshes with the third idle gear 54 rotates counterclockwise in the figure. This state is shown in FIG. That is, the rotation direction of the separation roller gear 53 is the same regardless of whether the platen gear 7 rotates in the forward or reverse direction. The printing paper S is supplied by moving the carriage 9 to the standby position HP in FIG. 3 as will be described later.
[0030]
  The basic operation of the ink jet printer 1 having such a configuration is that the print paper supplied from the paper feed cassette 5 or the manual paper feed unit 3 is conveyed by the platen roller 6 and the carriage 9 and the print head according to the command signal from the host 22. By driving and controlling 10, characters, symbols, graphics, etc. are printed on the printing paper. When printing is performed, the platen roller 6 sends a line on which printing paper is printed to a position facing the print head 10 and stops there. The carriage 9 is driven by the CR motor 12 at a predetermined printing speed, and during that time, the print head 10 ejects ink in accordance with a command signal and printing is performed.
[0031]
  Next, the actual operation when a print command is input from the host 22 to the inkjet printer 1 will be described with reference to the flowchart of FIG.
  The ink jet printer 1 is normally in a state of waiting for a print command from the host 22 (S1). If there is a print command (S1: Yes), the process proceeds to S2. In S2, it is determined whether or not the stop position of the carriage 9 is the standby position HP (see FIG. 3). If the carriage 9 has stopped at a position other than the standby position HP (S2: No), the carriage 9 is moved to the standby position HP by the retraction program in S3, and then the process proceeds to S4. If the carriage 9 is stopped at the standby position HP (S2: Yes), the process proceeds to S4 as it is.
[0032]
  At this time, since the carriage 9 exists at the standby position HP, the switching mechanism 30 in FIG. 5 has the kick portion 46 not kicked by the carriage 9, so that the LF idle gear 41 is moved to the arrow A by the idle kicker 43 in the solid line state. Pushed rightward, the biting teeth 40 are engaged with the platen gear 7. Therefore, the purge system is not driven.
[0033]
  In S4, paper feeding is performed by a paper feeding program. That is, the LF motor 29 reversely rotates and the paper feed gear train rotates as shown in FIG. 7, and one sheet of printing paper is supplied from the paper feed cassette 5 to reach the platen roller 6, but the platen roller 6 reversely rotates (FIG. 7 is clockwise), the printing paper is not placed on the platen roller 6. Next, the LF motor 29 is rotated forward, the paper feed gear train is rotated by a predetermined amount as shown in FIG. 6, the platen roller 6 is rotated forward (clockwise in FIG. 6), and the printing paper is printed on the platen roller 6. 10 to a position where it can face 10.
[0034]
  At this time, the carriage 9 is located at the standby position HP, and is outside the range through which the printing paper passes as described with reference to FIG. . Accordingly, it is possible to prevent the print surface of the print head 10 from being deteriorated and the printing paper from being stained. Further, since the LF idle gear 41 and the purge gear 42 are separated in the switching mechanism 30, the reverse rotation of the LF motor 29 is not transmitted to the purge system. Therefore, the print head 10 is not damaged or the surroundings are not contaminated by the backflow of ink from the purge device 18.
[0035]
  In step S5, one page is printed on the supplied printing paper. Since the carriage 9 during printing moves within the printing range p in FIG. 3, the switching mechanism 30 in FIG. 5 is in a state of engaging with the platen gear 7 (solid line state), as in the case where it is in the standby position HP. Therefore, the purge system is not driven.
  When printing for one page is completed, the process proceeds to S6, and it is determined whether the stop position of the carriage 9 is the standby position HP as in S2. Since the stop position of the carriage 9 at this time varies depending on the print end position in the last line of the printing in S5, this determination is required. If the carriage 9 has stopped at a position other than the standby position HP (S6: No), the carriage 9 is moved to the standby position HP by the retraction program in S7, and then the process proceeds to S8. If the carriage 9 is stopped at the standby position HP (S6: Yes), the process proceeds to S8.
[0036]
  In S8, the paper is discharged by the paper discharge program. That is, the LF motor 29 rotates forward and the paper feed gear train rotates as shown in FIG. 6, and the printed paper on the platen roller 6 is discharged. At this time, the carriage 9 is located at the standby position HP as in S4 and is outside the range through which the printing paper passes, so that the print head 10 is not attacked by the trailing edge of the discharged paper. Accordingly, it is possible to prevent the print surface of the print head 10 from being deteriorated and the printed paper from being stained.
  When the printed paper is discharged, it is determined in S9 whether there is a remaining print data. If there is remaining data (S9: Yes), the process returns to S4 and the operations up to S8 are repeated to continue printing. When all the print data has been printed, it is determined No in S9, and the process proceeds to S10.
[0037]
  In S10, the carriage 9 is moved to the purge position CP (see FIG. 3), and the process returns to S1 to wait for the next print command. This is because the purge operation is not necessarily performed, but there is a case where there is a considerable time until the next print command, so that the print head 10 is covered with the cap 15 of the purge device 18 to prevent the discharge port from being dried. At this time, the switching mechanism 30 of FIG. 5 is in a state of meshing with the purge gear 42 (two-dot chain line state), and therefore, if there is a purge command from the CPU 20, the rotation of the LF motor 29 is transmitted to the purge system. Is purged. When purging is performed, defective ink (including bubbles) in the print head 10 is sucked to the cap 15 side by a negative pressure, and the print head 10 is recovered to a good discharge state.
  This is the end of the flow.
[0038]
  As described above in detail, in the inkjet printer 1 according to the present embodiment, when a print command is issued, the carriage 9 is first moved to the standby position HP in the movement range m and then printed on the platen roller 6. Since the paper is supplied and printing is performed, the carriage 9 does not exist within the range through which the paper passes when the printing paper is supplied. Therefore, the print head 9 is not attacked by the leading edge of the paper. For this reason, deterioration of the printing surface of the print head 10 and contamination of the printing paper are prevented. At this time, in the switching mechanism 30, the LF idle gear 41 and the purge gear 42 are separated by the urging of the pulling spring 47. Therefore, it is possible to prevent the print head 10 from being damaged or surrounding contamination from being caused by the back flow of the ink from the purge device 18.
[0039]
  When printing for one page is completed, the carriage 9 is first moved to the standby position HP, and then the printed paper on the platen roller 6 is discharged. The carriage 9 does not exist within the range through which the paper passes, so that the print head 9 is not attacked by the trailing edge of the paper. For this reason, as in the case of paper feeding, deterioration of the printing surface of the print head 10 and contamination of the printing paper are prevented.
[0040]
  Further, in the switching mechanism 30, only when the carriage 9 is positioned at the purge position CP in the movement range m, the kick portion 46 is kicked by the carriage 9 and the bias of the pulling spring 47 is released, and the bias of the compression spring 45 is released. Accordingly, the gear teeth 39 of the LF idle gear 41 are connected to the purge gear 42, so that the purge device 18 is not driven when the carriage 9 is located at a position other than the purge position CP, and the purge device 18 rotates in the reverse direction. The harmful effect of being transmitted is prevented. On the other hand, when the carriage 9 is positioned at the purge position CP, the recovery operation by the purge device 18 is possible. When the recovery operation is performed, defective ink in the print head 10 is discharged to the cap 15 side and the discharge state is improved. .
[0041]
  In addition, this invention is not limited to the said Example, Of course, various improvement and deformation | transformation are possible within the range which does not deviate from the summary of this invention.
  For example, in the embodiment, the switching mechanism 30 is configured to selectively connect the LF idle gear 41 to only one of the platen gear 7 and the purge gear 42. May be always connected, and only the connection relationship between the biting teeth 39 and the purge gear 42 may be switched by the carriage 9.
  In the above-described embodiment, the position of the carriage 9 is detected by the drive signal of the CR motor 12. However, a reader that reads the scale of the position gauge 14 may be provided in the carriage 9 to detect the position.
[0042]
【The invention's effect】
  As explained above, according to the present invention,Recovery that print head receives recovery action by recovery means When the carriage moves to the position, the restriction on the idle gear of the restriction member is released by this carriage, and the drive motor drive is connected to the recovery means, so that the recovery operation of the print head by the purge device is possible, and the recovery When the operation is performed, defective ink in the print head is ejected, and the ejection state can be improved. Further, when the carriage does not move to the recovery position of the print head, the restriction on the idle gear of the restriction member is not released, so the drive of the drive motor is not coupled to the recovery means,Even if the drive motor reversely rotates for paper feeding operation or the like, the reverse rotation is not transmitted to the recovery means, and backflow of ink is prevented in the recovery means.
[0043]
  Also,When the idle gear slides, it always meshes with the outer peripheral surface of the drive gear, so that it can be moved horizontally by being guided by the tooth surface of the drive gear, and can smoothly mesh with the outer peripheral surface of the purge gear or the platen gear. Further, the idle gear, the purge gear, and the platen gear are not arranged on the same axis, but can be arranged with their shaft positions shifted so as to be able to mesh with the idle gear.
  Further, when the carriage is not positioned at the recovery position, the idle kicker moves the idle gear in the direction of the platen gear by the second urging member, and the driving force of the drive motor is transmitted to the transport roller. When located in a position other than the above, the recovery means is not driven, and it is possible to prevent adverse effects caused by reverse rotation of the purge device.
[Brief description of the drawings]
FIG. 1 is an external perspective view of an ink jet printer according to an embodiment.
FIG. 2 is a perspective view showing a recovery mechanism, a paper feed mechanism, and the like of the ink jet printer.
FIG. 3 is an explanatory diagram showing a positional relationship such as a retracted position and a platen roller width in a carriage movement range.
FIG. 4 is a control block diagram of the ink jet printer.
FIG. 5 is a diagram illustrating a configuration of a transmission gear switching mechanism.
FIG. 6 is a diagram illustrating a state during forward rotation of a paper feed gear train.
FIG. 7 is a diagram illustrating a state when a paper feed gear train rotates in reverse.
FIG. 8 is a flowchart showing an operation when there is a print command.
FIG. 9 is a diagram illustrating a state in which a print head is attacked by a leading edge of a printing paper supplied in a conventional apparatus.
[Explanation of symbols]
  1 Inkjet printer
  6 Platen roller
  9 Carriage
  10 Print head
  18 Purge device
  20 CPU
  24 ROM
  29 LF motor
  41 LF idle gear
  42 Purge gear
  45 Compression spring
  46 Kick club
  47 Spring
  53 Separation roller gear
  CP recovery position
  HP standby position

Claims (3)

A print head that ejects ink onto printing paper;
A transport roller for feeding printing paper to the print head;
A carriage mounted with the print head and movable in the axial direction of the transport roller;
Recovery means for recovering the print head;
A switching mechanism for driving either the recovery means or the transport roller;
A drive motor that drives the recovery means or the transport roller via the switching mechanism,
The switching mechanism includes a platen gear that drives the transport roller;
A purge gear for driving the recovery means;
An idle gear slidable between the platen gear and the purge gear;
A first urging member that urges the idle gear to move in the purge gear direction;
A regulating member that regulates movement of the idle gear in the purge gear direction by the first biasing member,
When the carriage moves to a recovery position where the print head receives a recovery operation by the recovery means, the carriage moves the restriction member to a non-functional position for releasing the restriction on the idle gear, and the idle gear is 1. An ink jet printing recording apparatus , wherein the biasing member is biased to a position connectable to a purge gear by one biasing member . The idle gear includes an outer peripheral surface of the purge gear, a gear tooth that meshes with an outer peripheral surface of the platen gear,
A meshing tooth meshing with the outer peripheral surface of the drive gear for transmitting the drive of the drive motor,
2. The ink jet printing apparatus according to claim 1, wherein the idle gear slides in mesh with the drive gear and meshes with either the purge gear or the platen gear. The regulating member is an idle kicker that abuts against an axial end surface portion of the idle gear;
A second urging member that urges the idle kicker to move the idle gear in the platen gear direction;
3. The ink jet printing recording apparatus according to claim 1, wherein an urging force of the second urging member is larger than an urging force of the first urging member . 4.

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