JP3018818B2 - Inkjet serial printer and carriage motor controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of a pulse motor for moving a carriage of a printer, and more particularly, to control of an exciting current when the pulse motor is stationary.

[0002]

2. Description of the Related Art In a serial printer, a print head mounted on a carriage performs printing while scanning the surface of a sheet. As a carriage motor for running the carriage, a pulse motor whose position and speed can be easily controlled is preferably used. While no printing is being performed, the pulse motor is stationary, during which time the pulse motor is not completely off. While stationary, the pulse motor is supplied with a constant exciting current enough to maintain the stationary position against a weak external force such as a small vibration generated even under a normal use environment.

[0003]

One problem of the prior art in which a constant exciting current is always supplied to the carriage motor even at rest is a rise in temperature around the carriage due to heat generated by the carriage motor. In particular, in the case of the ink jet type print head, there is a problem that the evaporation of the ink at the tip of the ink nozzle is promoted due to the temperature rise of the print head.

[0004] Another problem is that when an external force higher than usual is applied, the actuator is displaced from the rest position. In particular, in the case of a print head of an ink jet type equipped with an ink cartridge, if the cartridge becomes nearly empty during printing, printing can be paused and the cartridge can be replaced. The position of the print head may be displaced. Therefore, the nozzle surface of the head may be rubbed by the platen or paper. When printing is resumed after the cartridge replacement, a home seek (operation of returning the carriage to the home position and confirming the origin of the position coordinates) is always performed, and the printing resume position is determined again based on the coordinate origin. I have to.

Accordingly, an object of the present invention is to increase or decrease the excitation current supplied when a pulse motor used as a carriage motor is stationary in a serial printer in accordance with the stationary force required for the carriage, thereby enabling the carriage motor to operate. It is an object to suppress heat generation as much as possible and to prevent the carriage from being displaced from a stationary position.

[0006]

An ink jet serial printer according to the present invention has a carriage on which a print head and a cartridge are mounted, and caps the print head when printing is not performed for a predetermined time. A sheet sensor for detecting the presence or absence of a sheet on the platen, and when a sheet is detected by the sheet sensor in the cap, a first excitation current is supplied to a carriage motor to cause the sheet to be detected in the cap. When a sheet is not detected by the sensor, a second excitation current smaller than the first excitation current is supplied to the carriage motor, and when the cartridge is replaced, the carriage motor is supplied with a second excitation current larger than the first excitation current. It is characterized in that a third exciting current is passed. Further, the carriage motor control device according to the present invention includes a detection unit that detects a predetermined state related to printing, and an excitation of the carriage motor according to a state detected by the detection unit when the carriage motor is stationary. Exciting current changing means for changing the magnitude of the current.

In a preferred embodiment of the present invention applied to an ink-jet serial printer using a printer having a print head of a type having an ink cartridge mounted thereon, a carriage is continuously stopped at a home position for a predetermined time or more. And a means for detecting that the ink cartridge is stationary for replacing the ink cartridge. When the carriage is at rest at the home position for a predetermined time or more, the exciting current of the carriage motor is set to zero, and heat generation of the carriage motor is avoided. Further, when the cartridge is stationary for replacement, the exciting current is set to a value larger than usual, and a strong resting force is generated such that the carriage can be reliably stopped during the replacement operation.

[0008]

The exciting current of the carriage motor is increased or decreased according to the state of the carriage. Thus, when no static force is required, the exciting current is reduced to avoid heat generation of the motor, and when a strong static force is required, the exciting current is increased to increase the required static power. Force is generated.

[0009]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of an ink jet serial printer equipped with a carriage motor control device according to the present invention.

In FIG. 1, a data processor 5 in the serial printer 1 receives print data from a host computer 3 and receives data for controlling the travel of a carriage, data for controlling the drive of a print head, And data for controlling the paper feed.

The carriage controller 7 receives the data for controlling the carriage traveling from the data processor 5 and controls the rotation of the carriage motor 11 via the carriage motor driver 9. Thereby, the carriage 1
3 is controlled.

The head controller 15 receives data for print head drive control from the data processor 5 and controls the ink ejection operation of the print head 19 via the head driver 17.

A paper feed controller 29 receives data for paper feed control from the data processor 5 and controls the rotation of a paper feed motor 33 via a paper feed driver 31. Thus, the taking in, transporting and discharging of the paper 37 by the paper feed roller 35 and the platen 23 are controlled.

A pulse motor is used as the carriage motor 11. The control of the exciting current of the pulse motor 11 is performed by the carriage controller 7.

The print head 19 is of a type having a built-in replaceable ink cartridge. The print head 19 is mounted on the carriage 13 and the carriage 1
3 is moved linearly along the surface of the platen 23.

At one end of the traveling path of the carriage 13, a home position, which is the origin of the position coordinates, is defined. When the carriage 13 enters the home position, the carriage 13 is stably stopped at the home position by the elastic stopper 27. When the carriage 13 is at this home position, the home position sensor 25 detects this and sends a home position signal to the carriage controller 7. The home position signal input to the carriage controller 7 is used for exciting current control when the carriage motor is at rest, as described later.

In the vicinity of the position where the print head 19 faces the platen 23, a paper sensor 21 for detecting the presence or absence of the paper 37 on the platen 23 is provided. The paper presence signal generated by the paper sensor 21 means that paper is substantially present in front of the print head 19. The sheet presence signal is input to the paper feed controller 29 and the carriage controller 7, and is used in the carriage controller 7 to control the excitation current when the carriage motor is at rest, as described later.

The control panel 39 is provided with a power switch and various control buttons. Among the various control buttons, in addition to various control buttons for performing well-known functions, special control buttons for exchanging the ink cartridge from a normal state in which the printer 1 can perform printing (hereinafter, referred to as a print mode) are provided. A control button for setting a state (hereinafter, referred to as an exchange mode), canceling the exchange mode and returning to the print mode again is also included. This control panel 39
Are input to the data processor 5, the carriage controller 7, and the paper feed controller 29. Among these button signals, signals indicating the setting and cancellation of the exchange mode are as follows:
As described later, in the carriage controller 7,
It is used as a trigger for starting and ending the cartridge exchange mode.

FIG. 2 shows the carriage 13 and the print head 1.
FIG. 9 is a perspective view showing a schematic structure of No. 9;

The carriage 13 includes a carriage motor 11
, And travels along the guide shaft 41. This carriage 13
The side facing the paper 37 of the print head 19 registered in
An array of ink jet nozzles (not shown) is arranged to form a nozzle surface 19A, and a concave portion is provided on the side opposite to the nozzle surface 19A, where a replaceable ink cartridge for supplying ink to the nozzles is provided. 45 is fitted.

The paper sensor 21 (not shown) detects the presence or absence of paper at a position 21A slightly upstream in the paper feeding direction from the position where the nozzle surface 19A of the print head 19 scans the paper.

At the home position, a cap member 47 biased by a spring is provided. The cap member 47 automatically comes into close contact with the nozzle surface 19A of the print head 19 while the carriage 13 is at the home position in order to prevent evaporation of ink from the ink jet nozzles (this operation is called capping).

The excitation current control of the carriage motor 11 performed by the carriage controller 7 of FIG. 1 under the above configuration will be described below.

In this embodiment, the excitation current of the carriage motor is controlled in three stages of "non-excitation", "normal hold" and "strong hold" when the motor is stationary. Here, "non-excitation" is to reduce the excitation current to zero, and "normal hold" is to apply a relatively weak static force that can maintain the static position in a normal use environment as conventionally performed. The "strong holding" is a relatively large exciting current that can maintain a stationary position against a relatively strong external force that may be applied in an ink cartridge replacement operation. Is flowing.

FIG. 3 shows a flow of an operation for controlling the carriage motor in the print mode by turning on the power and in the print mode.

In FIG. 3, when the power is turned on (S
1) First, an initial setting of the printer 1 is performed (S).
2). In this initial setting, the carriage 13 is returned to the home position, and the print head is capped.
At this position, the carriage motor 11 is normally excited, and the LED display indicating the print mode is started.

Next, it is checked whether a request for an exchange mode set has been received from the control panel 39, and if not, a capping permission flag is checked next (S4). This capping permission flag is set to “1” when the printing mode is not performed in the print mode for 3 seconds or more. The “1” means that the carriage 13 can be returned to the home position for capping. . Immediately after the power is turned on, this flag is set to “0” by the initial setting, so that the control proceeds to step S5.
Then, it is checked whether or not to print, that is, whether or not print data has been input from the host computer 3. If there is no input of print data, the process returns to step S3 and repeats the same operation.

When print data is input, the three-second timer is reset (S6), and then the capping flag is checked (S7). Capping flag "1"
Means that the print head is currently in a capping state. Immediately after the power is turned on, this flag is initially set to "1", so that control proceeds to step S8, where the non-excitation flag is checked. The non-excitation flag “1” means that the carriage motor 11 is in the non-excitation state. Immediately after the power is turned on, this flag is initially set to "1", so that control proceeds to step S9, where the non-excitation flag is set to "0". Subsequently, home seek is performed (S10), and printing processing is performed according to the input print data (S11). In this printing process,
Since the carriage 13 travels out of the home position, the capping flag is set to “0”.

When the printing process for the input printing data is completed, a 3 second timer is started (S12).
The control returns to step S3, and unless there is a request to set the exchange mode, the control proceeds to step 5 to check whether or not there is a subsequent input of print data. If the subsequent print data is input before the 3-second timer times out, the control proceeds to step S7, where the 3-second timer is reset (S6). Since the capping flag is now "0", Jumps to step S11 to perform the printing process. After the end of the printing process, the three-second timer is started again (S12).

In this manner, the printing process is performed as long as the print data is successively input without leaving an interval of 3 seconds or more. During this time, the excitation current of the carriage motor does not fall below the current value of the normal hold.

After the printing process is completed, if three seconds elapse without inputting the next print data, a three-second timer generates a time-out signal, and this is used as a trigger to start an interrupt process (S16). In this interrupt processing, first, the capping flag is checked (S17).
Since this flag is "0" immediately after the end of the printing process and after entering this interrupt process, the control proceeds to step S21, where the capping permission flag is set to "1".
Then, the interrupt processing ends.

When the interrupt processing is completed, the control is restarted from step S3. Then, when the operation proceeds to step S4, the capping permission flag is "1", so that the operation proceeds to step S13, where the carriage is returned to the home position, and the print head 19 is capped. Next, the capping permission flag is set to "0", and the capping flag is set to "1" (S15). Subsequently, a three-second timer is started (S15), and the control returns to step S3.

Thereafter, if there is no input of print data, the control repeats the loop of steps S3 to S5. If three seconds elapse during this time, a timeout signal is generated again and the interrupt process is started (S16).

In this interrupt processing, since the capping flag is "1", the control proceeds to step S18, where the platen 23 is controlled by the signal from the paper sensor 21.
It is checked whether there is no paper 37 above. If there is no paper, it is possible to judge that printing of one document has been completed for a while and there is little possibility that print data will be input immediately thereafter. Then, the non-excitation flag is set to "1" (S20), and the interrupt processing is terminated. on the other hand,
If paper is detected in step S18, it is determined that printing of one document has not been completed yet, and there is a possibility that subsequent print data may be input immediately. In this case, the interrupt processing is immediately terminated. . When the interrupt processing ends, the control is restarted from step S3.

As described above, in the print mode, if there is no input of print data for 3 seconds or more, the carriage 13 is returned to the home position and capping is performed. In this capping state, print data is further output for 3 seconds or more. If there is no input, the excitation current of the carriage motor 11 is switched from the normal hold state to the non-excitation state. In this non-excitation state, the carriage 13 is mechanically fixed to the home position by a stopper, so there is no risk of displacement, and there is no heat generation in the motor because the excitation current is zero.

In this non-excitation state, when print data is input again, the control proceeds to step S6, where the 3-second timer is reset. Then, home seek is performed to confirm the origin (S10), and again. Printing processing is executed (S11).

Now, in the above print mode,
When an exchange mode set request is received from the control panel 39 (S3), the control enters the exchange mode operation shown in FIG.

In this exchange mode, first, the carriage 13 is moved to a predetermined position suitable for cartridge exchange (S31), and the carriage motor 11 is put into a strong hold state at that position (S32). Subsequently, a 5-minute timer is started (S33), and the LED display that has been indicating the print mode is switched to the display that indicates the exchange mode (S34).

Next, it is checked whether a request to cancel the exchange mode has been received from the control panel 39 (S35). If the release request is received, the 5-minute timer is stopped (S36), and the carriage 13 is returned to the home position and stopped there (S38).
The carriage motor 11 is set to the normal hold state (S
38) Then, the LED display is returned to the display indicating the print mode (S39), and the control returns to the operation in the print mode of FIG. 3 again.

On the other hand, if the request to cancel the exchange mode has not been received in step S35, the strong hold at the predetermined position is maintained until the 5-minute timer times out.

If the 5-minute timer times out in the strong hold state (S40), the time usually required for cartridge replacement has passed, and there is a possibility that the user has forgotten to cancel the replacement mode. In this case, the 5-minute timer is stopped (S41), the carriage motor is set to the normal hold (S42), and LE
The D display is returned to the print mode display (S43). Subsequently, it is checked whether the request for setting the exchange mode has been entered again (S44). If not, the control is forcibly returned to the operation in the print mode in FIG. On the other hand, if the exchange mode setting request has been input again, the control proceeds to step S
Returning to 32, the strong hold is performed again.

As described above, in the exchange mode, the carriage motor is held strongly while the carriage 13 is stopped at the predetermined cartridge exchange position.
The carriage 13 does not move left and right even if a considerable force is applied during the cartridge replacement operation.
9A can be prevented from being rubbed with a platen or paper.

[0043]

As described above, according to the present invention,
When the carriage is at rest, the exciting current is increased or decreased so as to generate the required resting force according to the situation, so that the heat generation of the carriage motor can be suppressed as much as possible and the carriage from the rest position can be reduced. Deviation can also be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of an ink jet serial printer on which a carriage motor control device according to the present invention is mounted.

FIG. 2 is a perspective view showing a schematic structure of a carriage and a print head in the embodiment.

FIG. 3 is a flowchart showing an operation of carriage motor control in a print mode in the embodiment.

FIG. 4 is a flowchart showing an operation of carriage motor control in a cartridge replacement mode in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printer 7 Carriage controller 11 Carriage motor 13 Carriage 21 Paper sensor 25 Home position sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-113697 (JP, A) JP-A-59-214676 (JP, A) JP-A-60-40282 (JP, A) JP-A-63-1988 270187 (JP, A) JP-A-4-133775 (JP, A) JP-A-4-47560 (JP, U) JP-A-62-255451 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 19/30 B41J 2/01

Claims (6)

(57) [Claims] An ink-jet serial printer having a carriage on which a print head and a cartridge are mounted and capping the print head when printing is not performed for a predetermined time, wherein a paper sensor for detecting the presence or absence of paper on a platen. When a sheet is detected by the sheet sensor in the cap, a first excitation current is supplied to the carriage motor. When a sheet is not detected by the sheet sensor in the cap, the carriage motor is driven. Ink jetting, wherein a second exciting current smaller than the first exciting current is passed, and when the cartridge is replaced, a third exciting current larger than the first exciting current is passed to a carriage motor. Type serial printer. 2. An ink jet serial printer having a carriage on which a print head and a cartridge are mounted, and capping the print head when printing is not performed for a predetermined time. An ink jet serial printer, wherein an exciting current is larger than an exciting current supplied to a carriage motor in the cap. 3. A carriage having a print head mounted thereon,
An ink-jet serial printer that caps the print head when printing is not performed for a predetermined time. The printer has a paper sensor that detects the presence or absence of paper on a platen, and paper is detected by the paper sensor in the cap. An ink jet type serial printer wherein the exciting current of the carriage motor is reduced to zero only when the printer is not present. 4. A control device for a carriage motor of an ink jet serial printer which has a carriage on which a print head and a cartridge are mounted, and caps the print head when printing is not performed for a predetermined time. A carriage motor control unit that, when the carriage motor is stationary, changes the magnitude of the excitation current of the carriage motor in accordance with the state detected by the detection unit. apparatus. 5. The apparatus according to claim 4, wherein said detection means has a paper presence / absence detection means for detecting the presence / absence of paper on a platen, and said capping means for said excitation current changing means includes: A carriage motor control device, wherein the exciting current is reduced to zero in response to an output of a paper presence / absence detecting means. 6. The apparatus according to claim 4, wherein said detecting means includes replacement state detecting means for detecting that said carriage is stationary for replacing said cartridge, and said exciting current changing means includes: A carriage motor control device for increasing the exciting current in response to an output of the replacement state detecting means.