JP3593286B2 - Thermal transfer printer - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is directed to a thermal transfer printer suitable for selecting a desired ribbon cassette from a plurality of ribbon cassettes, automatically exchanging the ribbon cassette, mounting the carriage on a carriage, and transferring ink on an ink ribbon to a recording medium to perform recording. about the data.
[0002]
[Prior art]
Generally, a recording medium such as plain paper and an ink ribbon coated with a desired ink are supported in front of the platen, and a thermal head having a plurality of heating elements arranged reciprocally along the platen together with a carriage. The ink ribbon is paid out, and the heating elements of the thermal head are selectively heated based on the recording information, thereby transferring ink onto a recording medium and recording desired images such as characters and figures. 2. Description of the Related Art Thermal transfer printers are widely used as output devices such as computers and word processors because of high printing quality, low noise, low cost, and ease of maintenance.
[0003]
Also, conventionally, a plurality of ribbon cassettes having different ink colors are arranged so as to face the carriage, and a necessary ribbon cassette is selected from the plurality of ribbon cassettes and automatically transferred to the carriage. 2. Description of the Related Art A serial type thermal transfer printer called a cassette changer type which can be mounted to form a full-color image or the like is known.
[0004]
In such a conventional thermal transfer printer, in order to replace the ribbon cassette, the carriage is provided with a cassette carrier that can be moved toward and away from the carriage. The cassette carrier and the thermal head are both configured so that the operation position is controlled by an operation control cam driven by one cam drive motor including a stepping motor.
[0005]
That is, by rotating the operation control cam with the driving force of the cam drive motor, the operation control cam is moved down to the position where the cassette carrier is closest to the carriage when the recording operation is performed. The recording position that holds the head down state in contact with the platen together, the carrier down state in which the cassette carrier is waiting for the recording operation to be performed closest to the carriage, and the thermal head is separated from the platen The stand-by position holds both the raised head-up state, the carrier-up state in which the cassette carrier has risen so as to be most separated from the carriage, and the head-up state in which the thermal head has been separated from the platen when performing the ribbon cassette exchange operation. Less replacement positions It is also configured so as to be taken selectively three positions.
[0006]
[Problems to be solved by the invention]
However, in the conventional thermal transfer printer described above, due to the setting of the reference operation position of the operation control cam that is performed each time the initialization operation is performed, the thermal head and the platen in the head down state when performing the recording operation are moved. The pressing force changes every time the initialization operation is performed, and there is a problem that high-quality recording quality cannot be maintained for a long period of time.
[0007]
That is, the operation reference position of the operation control cam of the conventional thermal transfer printer is in a state in which the thermal head is most strongly abutted on the platen when performing the initialization operation of the thermal transfer printer. As shown in FIG. 7, the operation control cam 1 is rotated by a cam drive motor, for example, in a counterclockwise direction as a recording position, so that the thermal head fitted in the cam groove 2 of the operation control cam 1 is rotated. Position of the operation control cam 1 when the cam drive motor is stepped out by bringing the roller 3 as a follower provided at one end of the moving head contact / separation lever into contact with the inner wall 4 of the cam groove 2 so as to abut the inner wall 4. Is the reference position, that is, the cam angle is 0 degree. The number of steps of the cam drive motor is set to 0, and the operation control cam 1 controls the number of steps, which is the drive amount of the cam drive motor, based on this reference position. By driving only, the cam angle at the operation reference position of the operation control cam 1 at the standby position is set.
[0008]
As described above, in the conventional thermal transfer printer, each time the initialization operation is performed, the roller 3 is abutted against the inner wall 4 of the cam groove 2 so that the thermal head is in the state of the strongest contact with the platen. As described above, the reference position of the operation control cam 1 is set by synchronizing the cam drive motor by the contact, so that the position of the operation control cam 1 is displaced every time the initialization operation is performed due to an impact or the like. The reference position as the stop position of the control cam 1 varies.
[0009]
When the reference position of the operation control cam 1 varies, the operation reference position of the operation control cam 1, which is a position where the cam drive motor is rotated by a predetermined amount from this reference position, also varies, and every time the initialization operation is performed, When the operation control cam 1 is stopped at a different operation reference position, the pressure contact force between the thermal head and the platen at the time of executing the recording operation changes, and as a result, density unevenness occurs in the recorded image, There is a problem that high-quality recording quality cannot be maintained for a long period of time.
[0010]
The present invention has been made in view of these points, and an object thereof is to provide a thermal transfer printer capable of getting hold over a long period of time the recording quality of high quality.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the thermal transfer printer of the present invention according to claim 1 is characterized in that a position detector is disposed on one of a carriage and a cassette carrier, and a position detector is provided on the carriage and the cassette carrier. On the other side, a position sensor for detecting a position detector is provided, and when performing an initialization operation, the cassette carrier is moved by operating the operation control cam with the driving force of the cam drive motor, and the movement of the cassette carrier is performed. Position control for detecting the reference position of the operation control cam based on the input of the detection signal from the position sensor associated with the operation control cam, and setting the operation reference position of the operation control cam by controlling the driving amount of the cam drive motor based on the reference position. The point is that a part is provided. And, by adopting such a configuration, when setting the operation reference position of the operation control cam, the operation control cam is not affected, so that there is no displacement of the operation control cam and every time the initialization operation is executed. In addition, the operation control cam can be stopped at the same operation reference position, and as a result, the pressure contact force between the thermal head and the platen in the head down state can always be maintained at a constant value. Therefore, high-quality recording quality can be maintained for a long period of time.
[0013]
The characteristic of the thermal transfer printer of the present invention according to claim 2, in claim 1, position sensor, the identification mark is arranged in the ribbon cassette to determine the type of housing ink ribbon in the ribbon cassette The point is that it is configured to also serve as a cassette sensor for detection. In addition, by adopting such a configuration, components can be shared, so that cost increase can be reduced.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to embodiments shown in the drawings.
[0015]
Figures 1 5 shows the main part of an embodiment of a thermal transfer printer according to the present invention, FIG. 1 is a plan view showing a look at the carriage from above, FIG. 2 is a plan view showing the internal structure of the carriage, 3 is an enlarged view of an operation control cam, FIG. 4 is an enlarged front view of a position sensor and a position detector, FIG. 5 is a side view of FIG. 4, and FIG. 6 is a block diagram of control means.
[0016]
As shown in FIG. 1, a thermal transfer printer 11 according to the present embodiment has a carriage 12 having a substantially rectangular planar shape. The carriage 12 is reciprocally movable along a platen 14 as shown by a double-headed arrow A in FIG. 1 by the driving force of a carriage drive motor 13 (FIG. 6) composed of a stepping motor. The carriage drive motor 13 is electrically connected to a control unit 45 (FIG. 6) described later, and can be driven based on a control command sent from the control unit 45.
[0017]
As shown in FIG. 2, the carriage 12 is provided with a thermal head 16 fixed to a thermal head mounting base 15 so as to face the platen 14. The thermal head 16 includes a plurality of heating elements (e.g., a plurality of heating elements) that selectively generate heat based on recording data as desired recording information input by an appropriate input device (not shown) such as a host computer, an image reader, and a keyboard. 1 and 2 are arranged in a direction perpendicular to the main scanning direction, which is the moving direction of the carriage 12 indicated by the double arrow A in FIGS. In other words, the heating elements are arranged in a line in the direction of conveyance of the recording medium (not shown), which is called the sub-scanning direction.
[0018]
The thermal head mount 15 is fixed to one end of a head contacting / separating lever 18 (only a part of which is shown in the drawing) which is pivotally attached to a support shaft (not shown) provided at a desired position on the carriage 12. At the other end of the head contact / separation lever 18, a roller 19 (FIG. 3) is provided to project downward. The roller 19 is fitted in a cam groove 21 (FIG. 3) of an operation control cam 20 rotatably arranged on the carriage. The operation control cam 20 is formed so as to be rotatable by a cam drive motor 22 composed of a stepping motor disposed on the carriage 12, and the operation control cam 20 is rotated by the driving force of the cam drive motor 22. Thus, the thermal head 7 can be moved toward and away from the platen 2. The rotation of the operation control cam 22 can be transmitted to the screw gear 24 via the transmission gear 23.
[0019]
The carriage 12 includes, as an ink ribbon traveling device, a winding mechanism including a winding bobbin 26 projecting upward from the carriage 12 and a ribbon driving roller 27 for winding. A delivery mechanism constituted by a delivery bobbin 28 projecting upward from the upper side of the printer 12 and a delivery ribbon drive roller 29 is provided, and the ink ribbon accommodated in a ribbon cassette (not shown) is provided. In a predetermined direction.
[0020]
Returning to FIG. 1, a substantially flat cassette carrier 31 is disposed on the carriage 12 substantially in parallel with the carriage 12 so as not to interfere with the components disposed on the carriage 12. The cassette carrier 31 is for automatically exchanging a ribbon cassette (not shown) mounted on the carriage 12, and can be vertically moved in parallel by rotating a screw gear 24 protruding from the carriage 12. Is formed. That is, the cassette carrier 31 is configured to be able to contact and separate from the carriage 12 by rotating the operation control cam 20 with the driving force of the cam drive motor 22.
[0021]
A plurality of cassette holders (both not shown) for holding the ribbon cassette are provided above the moving path of the carriage 12, and the cassette carrier is held in a state where the carriage 12 faces the cassette holder in parallel. Is moved to transfer the ribbon cassette.
[0022]
That is, in the present embodiment, by rotating the operation control cam 20 with the driving force 22 of the cam drive motor, the operation control cam 20 causes the cassette carrier 31 at the time of executing the recording operation to come closest to the carriage 12. The recording position where both the carrier down state in which the thermal head 16 has descended and the head down state in which the thermal head 16 abuts on the platen 14, and the cassette carrier 31 which is waiting for the recording operation to be executed is closest to the carriage 12. And a standby position where the thermal head 16 holds the head-up state in which the thermal head 16 is separated from the platen 14 so that the cassette carrier 31 is most separated from the carriage 12 when the ribbon cassette exchange operation is performed. Increased carrier up status and thermal head 16 is configured to be taken selectively at least three positions of the changing position for holding together the head-up state of being separated from the platen 14.
[0023]
As shown in FIG. 3, the roller 19 at the standby position is located at a substantially central portion in the longitudinal direction of the cam groove 21 of the operation control cam 20 and is separated from the axis of the operation control cam 20. It is formed so as to be located near the outer periphery. Further, the roller 19 at the recording position is formed so as to be located near the inner wall 21 a of the cam groove 21 of the operation control cam 20 and near the axis near the axis of the operation control cam 20. Furthermore, the roller 19 at the exchange position is formed so as to be located near the outer wall 21 b of the cam groove 21 of the operation control cam 20 and near the outer periphery separated from the axis of the operation control cam 20.
[0024]
In the vicinity of the upper right portion of the carriage 12 in FIG. 1, a position sensor 34 composed of a reflection type photo sensor fixed to a sensor mount 33 is provided. When the position detector 35 disposed in the section is detected, the detection signal is transmitted to a control means 45 described later, which is electrically connected.
[0025]
More specifically, as shown in FIGS. 4 and 5, the position sensor 34 is fixed to a sensor mount 33 projecting upward from the carriage 12, and the position detector 35 is provided with an operation control cam. 20 is located below the position sensor 34 in the state where it is located at the recording position and the standby position (FIGS. 4 and 5). Further, as shown in FIG. 4, the position detector 35 of the present embodiment has a horizontally long through hole 36 penetrating in the thickness direction, and the position sensor 34 moves up or down the position detector 35. With the movement, the detection signal of the position detector 35 can be sent to the control means 45 twice.
[0026]
That is, when the position sensor 34 is opposed to a position between the upper edge 35a of the position detector 35 and the upper edge 36a of the through hole 36, and when the position sensor 34 is at a position below the lower edge 36b of the through hole 36. When facing, the detection signal of the position detector 35 is transmitted from the position sensor 34 to the control means. In addition, the through-hole 36 may be provided as needed according to a design concept or the like.
[0027]
Further, the position sensor 34 in the present embodiment is configured to also serve as a cassette sensor that detects an identification mark provided on a ribbon cassette for determining the type of the ink ribbon. That is, the position sensor 34 is provided at a height position at which the identification mark of the ribbon cassette mounted on the cassette holder can be detected.
[0028]
In the case where the position sensor 34 is provided separately from the cassette sensor without using the cassette sensor, the position sensor 34 may be provided on the cassette carrier 31 and the position detector 35 may be provided on the carriage 12. Good. Further, as the position sensor 34 in this case, a variety of sensors such as a non-contact type sensor such as a proximity switch and a contact type sensor such as a limit switch are selected as necessary according to the specifications and design concept of the printer. be able to.
[0029]
As shown in FIG. 6, the control unit 45 of the thermal transfer printer 11 of the present embodiment is for controlling the operation of each unit of the thermal transfer printer 11, and is used at least for electrical connection with each unit of the thermal transfer printer 11. It has an I / O interface 46, a CPU 47, and a memory 48 formed of ROM, RAM or the like having an appropriate capacity.
[0030]
The I / O interface 46 includes at least a carriage drive motor 13, a cam drive motor 22, a position sensor 34, a ribbon travel motor for driving an ink ribbon travel device (not shown), a transport motor for transporting a recording medium, and a power supply. Switches and various operation switches and display means provided on the operation panel are electrically connected.
[0031]
The memory 48 has at least a position control unit 49, and a control program for setting an operation reference position of the operation control cam 20 is stored in the position control unit 49. As the control program, when the initialization operation is performed, the operation control cam 20 is operated with the driving force of the cam driving motor 22 to move the cassette carrier 31, and the position sensor 34 from the position sensor 34 accompanying the movement of the cassette carrier 31 is used. An example in which the reference position of the operation control cam 20 is detected by inputting a detection signal, and the operation reference position of the operation control cam 20 is set by controlling the driving amount of the cam drive motor 22 based on the reference position. Can be.
[0032]
The memory 48 includes a control program for executing an initialization operation at the time of turning on the power, a control program for controlling an operation of bringing the thermal head 16 into and out of the platen 14 at the time of executing the recording operation, and a timing thereof. , A control program for controlling the moving speed, moving direction and moving position of the carriage, a program for detecting an abnormal conveyance of the recording medium, a carriage driving motor 13 and a cam for automatically changing the ribbon cassette. Various programs such as a control program for controlling the operation of the drive motor 22 and various data required for the recording operation are also stored.
[0033]
Next, the operation of the present embodiment having the above-described configuration will be described together with a method of setting an operation reference position of the operation control cam.
[0034]
According to the thermal transfer printer 11 of the present embodiment, when performing the initialization operation when power is supplied to the thermal transfer printer 11, the operation reference position of the operation control cam 20 is set.
[0035]
The operation reference position of the operation control cam 20 is set by operating the operation control cam 20 with the driving force of the cam drive motor 22 based on the control program stored in the position control unit 49 to move the cassette carrier 31 from the carriage 12. It starts by moving upward in the separated carrier up direction. When the cassette carrier 31 rises, the position detector 35 rises together with the cassette carrier 31. With the rise of the position detector 35, the position sensor 34 sends a detection signal of the position detector 35 to the control means.
[0036]
More specifically, when the position detector 35 rises, first, the position sensor 34 transmits an OFF signal to the control unit 45 because the position sensor 34 does not receive the reflected light. When the upper edge 35a of the position detector 35 faces the position sensor 34, the position sensor 34 receives the reflected light, and the position sensor 34 sends an ON signal to the control means 45. Next, when the position detector 35 further rises and the upper edge 36a of the through hole 36 of the position detector 35 exceeds the position sensor 34, the position sensor 34 stops receiving reflected light. To the means 45. Then, when the position detector 35 further rises and the lower edge 36b of the through hole 36 of the position detector 35 faces the position sensor 34, the position sensor 34 receives the reflected light. An ON signal is transmitted, and in this state, the ascent of the position detector stops.
[0037]
That is, the position sensor 34 sends a signal to the control unit 45 in the order of OFF-ON-OFF-ON with the ascending operation of the cassette carrier 31.
[0038]
Then, the control means 45 determines the number of steps, which is the drive amount of the cam drive motor 22 at the time when the second ON signal, which is the detection signal from the position sensor 34, is inputted, to the reference position of the operation control cam 20 (see FIG. Detected as 3).
[0039]
Next, based on the number of steps of the cam drive motor 22 at the reference position, by controlling the number of steps, which is the drive amount of the cam drive motor 22, the operation reference position of the operation control cam 20, more specifically, the execution of the recording operation. A standby position is set to hold both the carrier-down state in which the cassette carrier 31 is lowered so that the cassette carrier 31 comes closest to the carriage 12 and the head-up state in which the thermal head 16 is separated from the platen.
[0040]
Specifically, since the cassette carrier 31 cannot be stopped at the time when the second ON signal is input due to inertia or the like, the step of the cam drive motor 22 at the time when the second ON signal is input is performed. The position at which the cam drive motor 22 is driven by a predetermined number of steps so that the cassette carrier 31 moves toward the carriage 14 with respect to the reference step number is stored as an operation reference position. After the second ON signal is input, the cam drive motor 22 is further driven by the predetermined number of steps to move the operation control cam 34 to the set operation reference position and stop.
[0041]
As described above, according to the thermal transfer printer 11 of the present embodiment, the setting of the operation reference position of the operation control cam 20 is performed based on the input of the detection signal from the position sensor 34 accompanying the movement operation of the cassette carrier 31. The operation reference position of the operation control cam 20 is set in a state where the roller 19 can freely move in the cam groove 21 without the head down operation of the thermal head 16, and the roller 19 is There is no need to hit the inner wall 21a and the outer wall 21b. Therefore, when the operation reference position of the operation control cam 20 is set, the operation control cam 20 is not affected. Therefore, unlike the related art, there is no displacement of the operation control cam 20 and the operation is performed every time the initialization operation is performed. The control cam 20 can be stopped at the same operation reference position, and as a result, the pressure contact force between the thermal head 16 and the platen 14 in the head down state can be always maintained at a constant value.
[0042]
Therefore, according to the thermal transfer printer 11 of the present embodiment, it is possible to maintain high-quality recording quality for a long period of time.
[0043]
Further, according to the thermal transfer printer 11 of the present embodiment, since the position sensor 34 is configured to also serve as the cassette sensor, it is possible to use common components, thereby reducing the cost.
[0044]
Further, the present invention is not limited to the above-described embodiment, and can be variously modified as needed.
[0045]
For example, as a method of detecting the reference position, the second OFF of the ON-OFF-ON-OFF detection signal from the position sensor 34 accompanying the lowering operation of the cassette carrier 31 after the cassette carrier 31 is once raised. The reference position of the operation control cam 20 may be detected by inputting a signal, or the reference position of the operation control cam 20 may be detected by inputting the first ON or OFF signal.
[0047]
According to the thermal transfer printer of the present invention according to claim 1 as described above, when setting the operation reference position of the operation control cam, in order to not affect the operation control cam, there is no positional deviation of the operation control cam Each time the initialization operation is performed, the operation control cam can be stopped at the same operation reference position, and as a result, the pressure contact force between the thermal head and the platen in the head down state can be always maintained at a constant value. Has an extremely excellent effect. Therefore, high-quality recording quality can be maintained for a long period of time. And so on.
[0048]
Further, according to the thermal transfer printer of the present invention described in claim 2 , in addition to the effect described in claim 1 , since components can be shared, extremely excellent effects such as reduction in cost can be achieved. To play.
[Brief description of the drawings]
Thermal transfer Figure 1 is a plan view Figure 3 showing the internal structure of the plan view of looking at the carriage of an embodiment of a thermal transfer printer from above according to the invention Figure 2 of the thermal transfer printer of FIG. 1 the carriage 1 FIG. 4 is an enlarged front view of a position sensor and a position detector of the thermal transfer printer of FIG. 1; FIG. 5 is a side view; and FIG. 6 is a block diagram of control means of the thermal transfer printer of FIG. FIG. 7 is an explanatory diagram showing a relationship between a cam groove and a roller at a reference position of an operation control cam when an operation reference position of a conventional thermal transfer printer is set .
11 Thermal Transfer Printer 12 Carriage 14 Platen 16 Thermal Head 19 Roller 20 Operation Control Cam 21 Cam Groove 22 Cam Drive Motor 24 Screw Gear 31 Cassette Carrier 34 Position Sensor 35 Position Detector 45 Control Means 47 CPU
48 memory 49 position control unit

Claims (2)

A thermal head that can contact and separate from the platen,
A cassette carrier disposed to be detachable from the carriage for exchanging a ribbon cassette mounted on the carriage;
An operation control cam for controlling the operation of contacting / separating the thermal head from / to the platen, and the operation of contacting / separating the cassette carrier from / to the carriage;
A cam drive motor comprising a stepping motor for driving the operation control cam,
A thermal transfer printer configured to select a desired ribbon cassette from among the plurality of ribbon cassettes, automatically exchange the ribbon cassette, and mount the ribbon cassette on the carriage to perform recording.
A position detector is disposed on one of the carriage and the cassette carrier, and a position sensor for detecting the position detector is disposed on the other of the carriage and the cassette carrier,
When the initialization operation is performed, the cassette carrier is moved by operating the operation control cam with the driving force of the cam drive motor, and the operation is performed by inputting a detection signal from the position sensor accompanying the movement of the cassette carrier. A heat transfer unit for detecting a reference position of the control cam and controlling a drive amount of the cam drive motor based on the reference position to set an operation reference position of the operation control cam; Printer. The said position sensor is comprised so that the cassette sensor which detects the identification mark arrange | positioned at the said ribbon cassette in order to determine the kind of the ink ribbon accommodated in the ribbon cassette may be used. Item 2. The thermal transfer printer according to Item 1 .

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