JP3746954B2 - Printing device release method of printing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing unit release method for a printing apparatus suitable for printing relatively small size paper such as business cards and postcards.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a printing apparatus that performs printing on a relatively small size paper such as a business card or a postcard is known from, for example, Japanese Patent Laid-Open No. 2-206573.
[0003]
In this type of printing apparatus, normally, sheets are sequentially sent out from a paper feeding mechanism on which a large number of papers are set, and the fed-out paper is transported to a printing mechanism by a pre-stage transport mechanism, and a print head (thermal head) and ink Printing is performed by a thermal transfer method using a ribbon. The printed paper is then transported by the subsequent transport mechanism and discharged onto the paper discharge tray. In this case, when the sheet is conveyed to the printing mechanism and the sheet is placed on the platen, the printing unit including the print head and the ink ribbon at the release position is displaced to the set position, and the printing unit is pressed with a pressure spring (pressurization). The printing is performed by pressing the sheet with the member.
[0004]
[Problems to be solved by the invention]
By the way, in this type of printing apparatus, it is necessary to suppress the consumption of the ink ribbon outside the printing region as much as possible to avoid the generation of a waste ink ribbon. Therefore, normally, when the printing area is completed, the printing unit is quickly released from the paper and the ink ribbon feeding operation is stopped.
[0005]
However, the conventional printing apparatus has a problem that when the printing unit is released, dirt such as black streaks due to the ink ribbon adheres to the paper and the printing quality is deteriorated. FIG. 7A shows measured data of the acceleration G added to the printing unit during the printing operation. When the printing unit at the release position is displaced from time to, first, the release motor An acceleration Ga at the time of start-up is generated, and thereafter an acceleration Gb is generated when the printing unit comes into contact with the paper on the platen. When the print area is released and the printing section is released, acceleration Ge is generated when the printing section is separated from the paper, and the vibration (impact) at this time becomes a major factor of contamination. FIG. 7B shows the detection result of the reference position sensor that detects the reference position of the printing unit, and Xs shows the detected reference position. Further, FIG. 7C shows the operating state of the release motor, Zs is the operating period when the printing unit at the release position is displaced to the set position, and Zr is the displacement of the printing unit at the set position to the release position. The operating period is shown.
[0006]
The present invention solves such problems existing in the prior art. In addition to eliminating waste of the ink ribbon and saving resources and running costs, printing is performed by eliminating contamination on the paper. It is an object of the present invention to provide a printing unit release method of a printing apparatus that can improve quality and can be easily realized by improving a control method without requiring additional parts.
[0007]
[Means for Solving the Problems and Embodiments]
The printing unit release method of the printing apparatus M according to the present invention performs printing when the printing unit 1 including the ink ribbon 5 and the print head 6 that are pressed against the paper P on the platen 2 by the pressure member 3 is released. After starting the release operation by starting the release motor 7 for releasing the part 1, the printer 1 is operated until immediately before the printing unit 1 is separated from the paper P, and then the release operation is temporarily performed for a pause time Ts that can eliminate the preset vibration. The release operation is re-executed after the stop time Ts has elapsed.
[0008]
In this case, according to a preferred embodiment, if the release motor 7 uses the stepping motor 7s and starts the stepping motor 7s and then drives the stepping motor 7s by a preset setting step, the stepping motor 7s Can be suspended for the rest time Ts. In addition, a speed-dependent first torque limiter 10a can be provided in the take-up shaft rotation drive unit 9 that drives the take-up shaft 8 that takes up the ink ribbon 5 to limit the rotational torque of the take-up shaft 8, and The rotational torque of the winding shaft 8 can be limited by providing a speed-independent second torque limiter 10b.
[0009]
【Example】
Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.
[0010]
First, in order to facilitate understanding of the present invention, an outline of the printing apparatus M will be described with reference to FIG.
[0011]
The printing apparatus M includes a main body lower portion 61 and a main body upper portion 62 that opens and closes up and down with respect to the main body lower portion 61 using a rear hinge portion 60 as a fulcrum. The printing apparatus M shown in FIG. 8 has a front surface portion Mf on the right side, and a paper feed mechanism 63 is disposed on the front surface portion Mf, and the front transport mechanism 64 and the print mechanism are moved from the paper feed mechanism 63 toward the rear. 65, a rear-stage transport mechanism 66 and a paper discharge tray mechanism 67 are sequentially arranged. Reference numeral 68 denotes a control unit, and 69 denotes an operation panel.
[0012]
The paper feed mechanism 63 includes a paper feed guide mechanism 70 for setting a large number of papers P ... and a paper feed roller mechanism 71 for feeding the paper P one by one from the many papers P ... set in the paper feed guide mechanism 70. Prepare. The paper feed guide mechanism 70 includes a paper feed tray 73 that can be raised by a paper feed elevator mechanism 72 and lowered by a manual operation. A large number of sheets P are stacked on the paper feed tray 73 and set. Is done. The sheets P that can be set are a horizontally placed business card Pa, a vertically placed postcard Pb, and a vertically placed envelope Pc. Note that the upper surface position of the paper P is detected by a sensor, and the feed elevator mechanism 72 is driven and controlled, so that the height is always maintained within a certain range. On the other hand, the paper feed roller mechanism 71 is in contact with the uppermost surface of the set paper P ..., the pickup roller 74 for feeding the paper P ... forward in the transport direction, the feed roller 75 arranged in front of the pickup roller 74 in the transport direction, and the feed A retard roller 76 is provided below the roller 75, and the paper P is separated by the feed roller 75 and the retard roller 76 and fed forward one by one.
[0013]
The pre-stage transport mechanism 64 is configured by sequentially arranging a takeaway roller mechanism 77, a pre-registration roller mechanism 78, and a registration roller mechanism 79 in the horizontal direction, and prints the paper P ... fed from the paper feed roller mechanism 70. It has the function to convey up to. The intervals between the roller mechanisms 77 to 79 are set to be shorter than the minimum size of the paper P to be conveyed. In particular, the pre-registration roller mechanism 78 and the registration roller mechanism 79 have a skew correction function for keeping the angle (orientation) of the transported paper P ... constant and an interval between the transported paper P ... by controlling the rotation operation. In addition, a transport interval correction function for reducing the interval is provided.
[0014]
Next, the configuration of the printing mechanism 65 that can carry out the printing unit release method according to the present embodiment will be specifically described with reference to FIGS.
[0015]
Reference numeral 11 denotes a horizontal support shaft disposed below the paper feed roller mechanism 71. One end of the cassette loading frame 12 is rotatably attached to the support shaft 11 via a bearing. The cassette loading frame 12 has a cassette loading section 12s for loading the ink ribbon cassette C.
[0016]
On the other hand, an elevating drive unit 13 is disposed below the other end of the cassette loading frame 12. The elevating drive unit 13 includes a release motor 7 using a stepping motor 7s, an eccentric cam 14, a rotation transmission gear mechanism 16 that transmits the rotation of the release motor 7 to the shaft portion 15 of the eccentric cam 14, and the eccentric cam 14. A follower 17 fixed to the lower surface of the cassette loading frame 12 to be engaged is provided. The driven portion 17 includes an upper engagement portion 17u having a V surface on the lower surface and a lower engagement portion 17d having a V surface on the upper surface, and the upper engagement portion 17u and the lower engagement portion 17d. An eccentric cam 14 is arranged therebetween. Accordingly, when the release motor 7 is driven and controlled, the eccentric cam 14 rotates, and the other end portion side of the cassette loading frame 12 is displaced up and down according to the rotation angle of the eccentric cam 14. In addition, a fan-shaped shutter 21 is fixed to the shaft portion 15 and a transmission type optical sensor 22 whose optical path is opened and closed by the shutter 21 is attached. Thereby, the reference position sensor 23 for detecting the reference position Xs (FIG. 6) of the printing unit 1 is configured.
[0017]
On the other hand, 25 is a head support frame formed in a U shape in a side view. One end of the head support frame is rotatably attached to the support shaft 11 via a bearing, and the other end is below the cassette loading frame 12. Go up via. As shown in FIG. 3, the print head 6 is supported on the upper end of the other end of the head support frame 25 via the head support mechanism 26. The head support mechanism 26 has a positioning function with respect to the print head 6. The print head 6 uses a C-end surface type thermal head so that printing can be reliably performed even on thick or hard paper P such as business cards and postcards. Further, when a C-end face type thermal head is used, curling is likely to occur on the paper P. Therefore, the platen 2 is prevented from being curled by using a rubber roller having a rubber hardness of 80 degrees or more. The print head 6 is located immediately below the platen 2.
[0018]
Further, as shown in FIG. 3, a lower spring receiving portion 27 is fixed to the cassette loading frame 12, and an upper spring receiving portion 28 that is opposed to the lower spring receiving portion 27 at the upper side of the head support frame 25. And a pressure spring (pressure member) 3 is interposed between the upper spring receiving portion 28 and the lower spring receiving portion 27. Further, the cassette loading frame 12 is provided with a stopper 29 for restricting the upward displacement of the head support frame 25, and a spring 30 is provided between the fixed chassis and the cassette loading frame 12 as shown in FIG. It is installed and the cassette loading frame 12 is urged upward.
[0019]
On the other hand, the control unit 68 has various setting functions, storage functions, calculation functions, and control functions, and executes the release method according to the present embodiment by sequence control. The control unit 68 is connected to the release motor 7 and the transmissive optical sensor 22 described above, and is also connected to a registration sensor 31 that detects the front end of the sheet P being conveyed.
[0020]
With the above configuration, the support shaft 11, the cassette loading frame 12 supported by the support shaft 11 and provided with the driven portion 17 at the other end, and the head support frame 25 for supporting the print head 6 are connected to the ink ribbon 5 and the print. A transmission mechanism 32 that displaces the head 6 together is configured. This transmission mechanism 32 transmits the elevation displacement of the driven unit 17 by the elevation drive unit 13 to the print head 6, thereby causing the sheet P on the platen 2 to be displaced. The release mechanism performs the pressure contact of the print head 6 against the pressure and the pressure release.
[0021]
On the other hand, FIG. 4 shows a take-up shaft rotation drive unit 9 for driving the ink ribbon cassette C loaded in the cassette loading unit 12s. Reference numeral 8 denotes a take-up shaft attached to the take-up reel of the cassette C, and 33 denotes a supply shaft attached to the supply reel of the cassette C. The take-up shaft 8 has an integral driven gear 34, and the rotation of a drive gear 36 provided on the rotary shaft of the take-up motor 35 is transmitted to the driven gear 34 via a rotation transmitting portion 37. The rotation transmission unit 37 includes a first gear 37a, a second gear 37b, a third gear 37c, a fourth gear 37d, a fifth gear 37e, a sixth gear 37f, and a seventh gear 37g, and the first gear 37a has a drive gear. 36 meshes, and the driven gear 34 meshes with the seventh gear 37g.
[0022]
A speed-independent second torque limiter 10b is interposed between the first gear 37a and the second gear 37b. As the second torque limiter 10b, a spring-type slip clutch can be used. As a result, when the rotation transmission is performed but the rotation torque equal to or higher than the set rotation torque is applied, the slip occurs and the rotation torque is limited to a constant rotation torque. Furthermore, the input gear 41 provided on the input shaft 40 of the speed dependent first torque limiter 10a is meshed with the fourth gear 37d. An oil type rotary damper can be used as the first torque limiter 10a. The oil-type rotary damper (first torque limiter 10a) is filled with silicone oil, and as shown by Kd in FIG. 5, the rotational torque (load torque) generated increases as the rotational speed of the winding shaft 8 increases. It has the characteristic which becomes. On the other hand, the rotational output of the second torque limiter 10b exhibits a constant rotational torque characteristic as indicated by Ko in FIG. Therefore, if a speed-independent spring-type slip clutch and a speed-dependent oil-type rotary damper are provided and the characteristics of both are combined, the winding shaft 8 can be wound even if the rotational speed of the winding shaft 8 is different at the beginning and end of winding. As shown by Ks in FIG. 5, the rotational torque of the spindle 8 is small at the start of winding and increases as the winding ends. Therefore, when the ribbon tension is set (adjusted) to an optimum value, an ideal ribbon tension (tensile force) that is substantially constant from the start to the end of winding regardless of the winding diameter of the ink ribbon 5 on the winding shaft 8. Is maintained. In particular, in relation to the present embodiment, the problem of deviation from the optimal state due to the winding amount of the winding shaft 8 is solved despite the optimal setting (adjustment) for the rest time Ts and the like described later. Is done.
[0023]
Reference numeral 42 denotes a slip clutch mechanism using a spring-type slip clutch that receives rotation from an output gear 43 provided on the supply shaft 33, and applies a constant back tension to the supplied ink ribbon 5. Reference numeral 44 denotes a guide shaft for guiding the ink ribbon 5, and 45 denotes a guide plate for guiding the ink ribbon 5.
[0024]
Next, the operation of the printing mechanism 65 including the printing unit release method according to the present embodiment will be described according to the flowchart shown in FIG.
[0025]
First, when the power is turned on, the cassette loading frame 12 is in the lowered position shown by the solid line in FIG. Accordingly, the ink ribbon 5 (cassette C) and the print head 6 constituting the printing unit 1 are both lowered and are at a release position separated from the platen 2.
[0026]
If the paper P is transported from the preceding transport mechanism 64, the front end of the paper P is detected by the registration sensor 31 (step S1). Thereby, time measurement is started by the timer function of the control unit 68 (step S2). When the preset first set time Ta has elapsed, the rotation of the registration roller mechanism 79 driven by a registration motor (not shown) is stopped (steps S3 and S4). Thereafter, when the second set time Tb has elapsed, the registration roller mechanism 79 is driven to rotate (steps S5 and S6). Thus, in order to temporarily stop the rotation of the registration roller mechanism 79, the front end of the sheet P hits the stopped registration roller mechanism 79 and the sheet P is bent. At this time, when the front end of the sheet P hits the registration roller mechanism 79, the skew is corrected so that the front end is parallel to the axial direction of the registration roller mechanism 79, and the bending is within the bending allowable space Rw provided by the guide plate. To escape. Then, after this bending occurs, the registration roller mechanism 79 starts to rotate and starts transporting the paper P. Accordingly, the second set time Tb is set to a time during which the sheet P is moderately bent.
[0027]
If the third set time Tc has elapsed since the registration sensor 31 detected the paper P, the control unit 68 activates the release motor 7 (steps S7 and S8). “To” shown in FIG. 6 indicates the starting point of the release motor 7. Thereby, the eccentric cam 14 rotates, the follower 17 is displaced upward, and the cassette loading frame 12 is raised. In this case, the third set time Tc is set in consideration of the distance at which the front end of the conveyed paper P is positioned a predetermined distance ahead of the pressure contact position of the ink ribbon 5 with respect to the platen 2. As a result, when the cassette loading frame 12 is raised, the ink ribbon 5 is always in pressure contact with the lower surface of the paper P. Even when the thick paper P is used, the paper P The problem that the front end of the battery collides and gets dirty is avoided.
[0028]
On the other hand, the shutter 21 also rotates together with the rotation of the eccentric cam 14. If the shutter 21 rotates by a certain angle and the end of the shutter 21 is detected by the transmissive optical sensor 22, this position becomes the reference position Xs. When the reference position Xs has been reached, the release motor 7 (stepping motor 7s) is operated for a preset first setting step (number of pulses) and then stopped (steps S10 and S11). As a result, the printing unit 1 rises to the set position and presses against the paper P. In this case, as shown in FIG. 3, if the rising stroke of the cassette loading frame 12 is Ld and the rising stroke of the print head 6 is Lu, Ld-Lu becomes the compression amount of the pressure spring 3, and in this embodiment this compression The amount is set to about 2 [mm], and a pressing force of about 1 [MPa] is applied.
[0029]
On the other hand, printing is performed on the paper P by the printing unit 1. When the printing (printing area) is completed, a printing end command is output (step S12). In response to the output of the print end command, the release motor 7 is started, operated for a preset second setting step (number of pulses), and then stopped (steps S13 and S14). When the operation of the second setting step is completed, the time is started by the timer function of the control unit 68, and the release motor 7 is restarted after the preset rest time Ts has elapsed (steps S15 and S16).
[0030]
In this case, the timing for stopping the release motor 7 is set immediately before the printing unit 1 leaves the paper P. That is, the eccentric cam 14 is rotated by the activation of the release motor 7 and the cassette loading frame 12 is lowered, but the printing unit 1 is initially kept in pressure contact with the paper P by the elastic return of the pressure spring 3, and the cassette Since the printing unit 1 is separated from the sheet P from the position where the loading frame 12 is lowered by the above-described compression amount, that is, 2 [mm], the operation of the release motor 7 is stopped immediately before the cassette loading frame 12 is lowered by 2 [mm]. Let The lowered position of the cassette loading frame 12 can be accurately known based on the reference position Xs. The rest time Ts can be set to a relatively short time because it is sufficient that the vibration (impact) associated with the elastic return of the pressure spring 3 can be eliminated. On the other hand, after restarting, the release motor 7 is operated for a preset third setting step (number of pulses), and then stopped (step S17).
[0031]
Therefore, according to the printing unit release method according to the present embodiment, the release operation of the printing unit 1 is stopped for the pause time Ts immediately before leaving the paper P, and therefore vibration (impact) associated with the elastic return of the pressure spring 3 is achieved. Is absorbed within the rest time Ts. FIG. 6A shows measured data of the acceleration G added to the printing unit 1 during the printing operation, but no acceleration G is generated when the printing unit 1 moves away from the paper P. FIG. That is, the acceleration Ge when the conventional printing part release method shown in FIG. 7A is used does not occur when the printing part release method according to the present embodiment is used. Therefore, in addition to eliminating waste of the ink ribbon 5 and saving resources and running costs, it is possible to improve the print quality by eliminating the adhesion of dirt on the paper P, and control without requiring additional parts. It can be easily realized by improving the method.
[0032]
In FIG. 6, to is the drive time of the release motor 7 in the release position, Ga in FIG. 6A is the acceleration when the release motor 7 is started, and Gb is the paper P on the platen 2 by the printing unit 1. Acceleration that occurs when abuts against. In this case, the acceleration G was measured by an acceleration sensor 51 attached to the print head 6 as shown in FIG. FIG. 6B shows the detection result of the reference position sensor 23 that detects the reference position of the printing unit 1, and Xs shows the detected reference position. Further, FIG. 6C shows the operating state of the release motor 7, Zf is the operating period according to the first setting step described above, Zrrf is the operating period according to the second setting step described above, Ts is the pause time described above, and Zrr. Indicates the operation period by the third setting step described above.
[0033]
The embodiment has been described in detail above, but the present invention is not limited to such an embodiment, and the detailed configuration, shape, material, technique, and the like can be arbitrarily set within the scope of the present invention. Can be changed, added or deleted. For example, the pressure member is exemplified by the pressure spring 3, but may be replaced by another pressure member such as a pressure leaf spring. Although the stepping motor 7s is used as the release motor 7, the use of other types of motors is not excluded. Further, although the case where both the speed-dependent first torque limiter 10a and the speed-independent second torque limiter 10b are used is shown, the speed-dependent first torque limiter 10a is added to the speed-independent torque limiter 10a. When the function is included, only the first torque limiter 10a may be used.
[0034]
【The invention's effect】
As described above, the printing unit release method of the printing apparatus according to the present invention starts the release motor using the stepping motor that releases the printing unit and starts the release operation, and then operates until just before the printing unit leaves the sheet. Thereafter, the release operation is paused for a pause time that can eliminate the vibration set in advance, and the release operation is re-executed after the pause time has elapsed.
[0035]
(1) In addition to eliminating waste of the ink ribbon and reducing resource and running costs, it is possible to improve the print quality by eliminating the adhesion of dirt to the paper.
[0036]
(2) It can be easily realized by improving the control method without requiring additional parts.
[0037]
(3) According to a preferred embodiment, a speed-dependent first torque limiter is provided in the winding shaft rotation drive unit to limit the rotational torque of the winding shaft, and further, a speed-independent second torque limiter is provided. If the rotational torque of the take-up shaft is limited, the setting (adjustment) for the resting time or the like can always be maintained in an optimum state regardless of the take-up amount of the take-up shaft.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a processing procedure of a printing unit release method of a printing apparatus according to a preferred embodiment of the present invention;
FIG. 2 is an operation explanatory diagram including a printing mechanism including the printing unit and a control system;
FIG. 3 is an enlarged partial cross-sectional view of a part of a printing mechanism including the printing unit,
FIG. 4 is a configuration diagram of a cassette driving mechanism in the printing mechanism;
FIG. 5 is a diagram for explaining the operation of the cassette drive mechanism;
FIG. 6 is a timing chart showing the state of each part when the printing part release method is used;
FIG. 7 is a timing chart showing the state of each part when a printing part release method according to the prior art is used;
FIG. 8 is a schematic diagram of a printing apparatus provided with the printing mechanism;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Printing part 2 Platen 3 Pressure member 5 Ink ribbon 6 Print head 7 Release motor 7s Stepping motor 8 Winding shaft 9 Winding shaft rotation drive part 10a First torque limiter 10b Second torque limiter M Printing device P Paper Ts Rest time

Claims (5)

  In a printing unit release method of a printing apparatus for releasing a printing unit including an ink ribbon and a printing head pressed against a sheet on a platen by a pressure member, a release motor for releasing the printing unit is activated to perform a release operation. After starting, the printing unit is operated until just before it leaves the paper, and then the release operation is paused for a pause time during which the preset vibration can be extinguished, and the release operation is resumed after the pause time has elapsed. A printing unit release method for a printing apparatus, comprising:   The printing unit release method of a printing apparatus according to claim 1, wherein a stepping motor is used as the release motor.   3. The printing apparatus according to claim 2, wherein after the stepping motor is activated, if the stepping motor is operated for a preset setting step, the rotation of the stepping motor is temporarily stopped for the pause time. 4. Print part release method.   A speed-dependent torque limiter (first torque limiter) is provided in a take-up shaft rotation drive unit that rotationally drives the take-up shaft that winds up the ink ribbon, and the rotational torque of the take-up shaft is limited. A printing unit release method for a printing apparatus according to claim 1.   5. The printing according to claim 4, wherein a speed-independent second torque limiter is provided in the winding shaft rotation driving unit in addition to the first torque limiter to limit the rotational torque of the winding shaft. The printing part release method of the device.

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