JPH0825324B2 - Multi-head printer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a serial type multi-head printer having a plurality of printing heads arranged along a spacing direction.

[Prior art]

In all of the conventional multi-head printers, a plurality of print heads are driven by a single motor, and the print area that each print head receives is fixed.

In such a multi-head printer, when the characters to be printed on one line are evenly distributed over the entire width of the line, the printing speed increases in proportion to the number of print heads.

However, in the actual printing mode, the printing amount and the printing area are various, and most of them are biased to the left side of the line. For this reason, there is a drawback that only a specific print head is worn or the temperature thereof becomes high, and the print speed is not so much improved as compared with a single print head.

In particular, the shuttle type line printer has the drawbacks of large vibration and noise, large size and heavy weight, and is unsuitable as a terminal for OA (office automation).

[Object of the Invention]

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art. By equalizing the load applied to each print head corresponding to various printing modes, high-speed printing can be performed with a relatively small number of print heads. It is possible to realize a multi-head printer suitable for an OA terminal that is small, lightweight, and has less vibration and noise.

[Outline of Invention]

In order to achieve this object, the present invention provides a multi-head printer in which first and second print heads are arranged along a spacing direction, a first carriage having the first print head mounted thereon, and A second carriage equipped with a second print head; a first rotary motor mounted on the first carriage; a second rotary motor mounted on the second carriage; A first rotary motor, which converts the rotation of the rotary motor into a linear motion to move the first print head together with the first carriage in the spacing direction;
Second power conversion means connected to the rotary type motor for converting the rotation into a linear motion to move the second print head together with the second carriage in the spacing direction, and the first rotary type motor. A first sub-control unit that drives a motor and the first print head in synchronization with each other, and a second sub-control unit that drives the second rotary motor and the second print head in synchronization with each other. The received data of one line is divided by the first print head and the second print head so that the data of one line is divided, and the divided data is divided into the first and second data. It has a main control part which outputs to a sub control part.

〔Example〕

 Embodiments will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of a multi-head printer according to the present invention. In the drawing, 1 is a platen rotatably instructed by a pair of left and right side plates, and 2 is a printing sheet set on the platen 1. .

3a and 3b are self-propelled carriages that can be independently moved along the platen 1 in the spacing direction, and 4a and 4b are guide shafts that guide the carriages 3a and 3b. The carriage 3a is provided with a wire dot type print head (first print head) 5a, an ink ribbon cassette 6a, and a space motor (first rotary motor) described later, and the other carriage (second print head). The same print head (second carriage)
Print head) 5b, an ink ribbon cassette 6b, and a space motor (second rotary motor).

The ink ribbon cassettes 6a and 6b are attachable to and detachable from the carriages 3a and 3b, respectively, so that they can be converted.

In the present embodiment, by the control circuit described later, the space motors respectively mounted on the above-mentioned carriages 3a and 3b are independently driven, whereby the carriages 3a and 3b are self-propelled and printing is the earliest. The print heads 5a and 5b are respectively positioned at the print start position where the printing is completed. Thereafter, the carriages 3a, 3b are respectively operated while moving the printing heads 5a, 5b while moving in the spacing direction according to the individual operation sequences, and by the printing wires protruding from the printing heads 5a, 5b, the ink ribbon cartridge 6a, The printing paper 2 is strongly pressed against the platen 1 via the ink ribbon 6b to print a dot character on the printing paper 2.

In this way, the print heads 5a and 5b are individually mounted on the carriages 3a and 3b, and the carriages 3a and 3b are independently driven by separate motors, so that the print areas covered by the print heads 5a and 5b are provided. Since it can be changed, it is possible to evenly print with the two print heads 5a and 5b regardless of whether to print on the left half or right half of the line, and to shorten the time required to print one line. You can

FIG. 2 is a block diagram showing a control circuit in the above-described embodiment. In the figure, 7 is a main control unit for controlling the entire printer, which is mainly composed of a CPU, an I / O port, a timer, a memory and the like. ing.

8a is a spacing operation of the carriage 3a and the carriage
A sub-control unit (first sub-control unit) for controlling the printing operation by the print head 5a mounted on the carriage 3a, and 8b by the spacing operation of the carriage 3b and the print head 5b mounted on the carriage 3b. It is a sub-control unit (second sub-control unit) for controlling the printing operation. Further, 9a and 9b are head drive circuits for driving the print heads 5a and 5b, 10a and 10b are motor drive circuits for driving the space motors of the carriages 3a and 3b, and 11a and 11b are carriage drives 3a and 3b as described above. A space motor for pacing operation, 12 is a motor drive circuit, and 13 is a line feed motor driven by the motor drive circuit 12.

Reference numeral 14 represents the entire control circuit consisting of the above 7 to 12, and 15 is a signal line for print commands and print data input to the main controller 7 from an external device external to the present multi-head printer, and 16a and 16b. Is a signal line for sending a feedback signal from the space motors 11a, 11b to the sub control units 8a, 8b, and 17 is a signal line for sending a feedback signal from the line feed motor 13 to the main control unit 7. .

FIG. 3 is a flow chart showing the operation of the control circuit 14 described above. The operation of the present multi-head printer will be described in detail with reference to FIG. 3 and FIG.

<Reception of Print Command> The main control unit 7 of the present multi-head printer receives print character data for one line from an external device through the signal line 15.

<Sending of print instruction> The main control unit 7 uses two print heads 5a and 5b so that the time required for print processing of the received one line of data is minimized.
Are divided into two optimum print blocks so that they can be shared and printed, and the sub-control units 8a and 8b are instructed to print the respective print blocks.

At this time, the main control unit 7 sets the print start positions of the respective print heads 5a and 5b so as not to cause the collision of the two carriages 3a and 3b during the simultaneous printing operation of the two print heads 5a and 5b. Each sub-control unit controls the spacing direction when printing.
Instruct 8a and 8b at the same time as the print block.

<Movement to print start position> In the sub control units 8a and 8b, based on the instruction from the main control unit 7 described above, first, the print head is moved from the current carriage position.
Move the carriages 3a and 3b so that 5a and 5b are at their designated print start positions, respectively, by the space motors 11a and 11b.
By.

For example, the sub-control unit 8a uses the input of a trigger pulse, which will be described later, as a trigger to determine the rotation direction and drive signal of the motor drive circuit
Then, the space motor 11a is rotated by driving the motor drive circuit 10a according to the signal and the carriage 3a is moved. After that, the movement of the carriage 3a is repeated until the print head 5a reaches the print start position.

Here, when the space motor 11a is a DC motor or the like,
When the closed loop control is performed, the feedback signal input via the signal line 16a is used as the trigger pulse for the above-described repetitive operation. However, when the space motor 11a is controlled by open loop control, the trigger pulse for the above-described repetitive operation is generated inside the sub control unit 8a.

The control for positioning the print head 5b at the print start position is also performed by the sub-control unit 8b, the motor drive circuit 10b, the space motor 11b and the like in the same manner as described above.

<Printing Operation> After the positioning of the printing heads 5a and 5b to the printing start position is completed, the printing operation is started.

In the printing operation, the sub-control unit 8a sends the same signal to the motor drive circuit 10a as the above-described movement to the print start position in order to space the print head 5a in the direction instructed by the main control unit 7. At the same time, in order to print the print pattern corresponding to the current position of the print head 5a in the print block instructed by the main controller 7, the print instruction is given to the print head 5a via the head drive circuit 9a. As a result, the print head 5a performs printing by driving the print wire corresponding to the print pattern in accordance with the instruction from the head drive circuit 5a.

Thereafter, this printing operation is repeated while moving the carriage 3a until all the printing patterns of the printing block instructed by the main control unit 7 are printed.

When the printing of all the print patterns is completed, the sub-control unit 8a sends a signal to the main control unit 7 to notify the end of the print operation (hereinafter referred to as a print end signal), so that the print operation ends. To do.

Here, regarding the printing operation, the operation on the carriage 3a side centering on the sub control unit 8a has been described.
The same applies to the operation on the carriage 3b side centered on 8b, and both operations are performed in parallel.

<Line Feed Operation> Upon completion of the above-described print operation, the print end signals sent from the sub-control units 8a and 8b are both input to the main control unit 7, so that the main control unit 7 enters the line feed operation. .

Since the main control unit performs line feed, the line feed motor 13 is triggered by the input of a trigger pulse described later.
Sends the rotation direction and drive signal of the motor drive circuit 12,
The line feed motor 13 is rotated by the drive of the motor drive circuit 12 by the signal, and the print sheet 2 shown in FIG. 1 is line fed.

Thereafter, the line feed operation is repeated until the target line feed amount is reached.

Here, when the line feed motor 13 is a DC motor or the like and the closed loop control is performed, the feedback signal input to the main control unit 7 via the signal line 17 is used as the trigger pulse for the above-described repetitive operation. However, when performing the open control, the main control unit 7 generates the trigger pulse for the above-described repetitive operation.

As above, from <print command reception> to <line feed operation>
By repeating the above operations, the control circuit 14 causes the printer to continuously perform the printing operation.

An example of the operation of the print heads 5a and 5b at this time is shown in FIG. In the example shown in Fig. 4, the maximum print data is 80 characters /
Since there are only 50 characters from the left edge of the line, the print head
5a is the home position, that is, the initial position, and the print head 5b is positioned at the 24th character to be the print start position.
Both the print heads 5a and 5b are moved rightward so that the printing is completed at the same time.

FIG. 5 is an exploded perspective view showing the structure of the self-propelled carriage part used in the present invention. Since the carriages 3a and 3b have the same structure, only the carriage 3a is shown here. .

The space motor 11a is a flat DC brushless motor,
It is fixed to the lower surface of the carriage 3a with screws or the like. Reference numeral 18 denotes an optical sensor, which together with the slit disk constitutes an encoder for detecting the rotation angle of the space motor 11a. Reference numeral 19 is a pinion attached to the rotor shaft of the space motor 11a, 20 is a rack that meshes with the pinion 19, and 21 is a frame that supports the rack 20. The rack 20 is provided so as to extend in the moving direction of the carriages 3a, 3b, and the space motor 11 of the carriage 3b is installed in the rack 20.
It also meshes with a pinion 19 attached to the rotating shaft of b, and the two pinions 19 and one rack 20 convert the rotation of the space motors 11a and 11b into a linear motion.
1, a first power conversion means is configured.

Reference numeral 22 denotes a flexible cable attached to the carriage 3a together with the space motor and the like, which is connected to the control circuit 14 shown in FIG. 2, and the flexible cable 22 supplies electric power to the circuit parts mounted on the carriage 3a. Is supplied and signals are exchanged between the circuit parts and the control circuit 14.

In this mechanism, the space motor 11a is rotated by the electric power supplied from the control circuit 14 shown in FIG. 2 via the flexible cable 22, and the pinion 19 attached to the rotor shaft thereof is rotated. When the slit plate is rotated integrally with the pinion 19, a signal indicating the rotation angle is output from the optical sensor 18 to the control circuit 14, and the carriage 3a, the space motor 11a, by the reaction force from the rack 20 meshed with the pinion 19, The optical sensor 18, the pinion 19, the flexible cable 22 and the like move integrally.

Note that the present invention is not limited to the above-described embodiment, and for example, the two carriages 3a and 3b fixed to the frame may be used.
You may make it drive individually by one motor and two sets of transmission mechanisms.

Further, the number of print heads may be three or more, but two or three is desirable in view of the complicated mechanism and control circuit.

EFFECTS OF THE INVENTION As described above, according to the present invention, the first carriage on which the first print head is mounted, the second carriage on which the second print head is mounted, and the first carriage are mounted. Connected to the first rotary motor, the second rotary motor mounted on the second carriage, and the first rotary motor, and converting the rotation into a linear motion to move the first rotary motor. First power conversion means for moving the first print head in the spacing direction together with the carriage, and the second
First rotary type motor, which is connected to a rotary type motor for converting the rotation into a linear motion to move the second print head together with the second carriage in the spacing direction. A first sub-control unit that drives the motor and the first print head in synchronization with each other, and a second sub-control unit that drives the second rotary motor and the second print head in synchronization with each other. And dividing the received data of one line so that the first print head and the second print head share and print the data of the first line, and divide the divided data into the first and second data. Since it has a main control unit for outputting to the sub-control unit, the load on each print head can be distributed almost evenly. Therefore, it is possible to prevent only the specific print head from being worn or getting hot.
It is possible to achieve high-speed printing with a comparatively small printing head, reduce vibration and noise, and realize a small and lightweight multi-head printer suitable as an OA terminal.

Further, according to the present invention, since the rotary type motor is used as the power source of each carriage and the power converting means is connected to the rotary motor, the power ratio such as the gear ratio of the power converting means can be easily changed. Since the moving speed of the carriage can be made relatively high even if the motor itself is relatively low, the effect of realizing a high-speed printer can be obtained in this respect as well.

Further, according to the present invention, in order to independently control the two carriages and the two print heads, a main control unit that divides print data and a sub-control that controls each print head and a motor in synchronization with each other. Since the main control unit performs common control and the sub-control unit performs individual control unit, there is an effect that print control can be easily performed.

Further, the present invention provides the motor with an encoder,
Since the position of the print head can be directly detected by this encoder, there is an effect that the position of the print head can be accurately detected.

Furthermore, according to the present invention, since the rack and the pinion are used to change the power of the motor to drive the carriage, the rotation of the pinion enables the carriage to be accurately positioned, and thus the print head to be positioned. Since a common rack is used for each pinion of the motor provided in each carriage, it is possible to move two carriages without preparing a plurality of traveling paths.

[Brief description of drawings]

1 is a perspective view showing an embodiment of a multi-head printer according to the present invention, FIG. 2 is a block diagram showing a control circuit of the embodiment shown in FIG. 1, and FIG. 3 is a flow chart showing the operation thereof. FIG. 5 is an explanatory view of the operation of the print head, and FIG. 5 is an exploded perspective view showing the structure of a self-propelled carriage used in the present invention. 1 ... Platen, 2 ... Printing paper, 3a, 3b ... Carriage, 4a, 4b ... Guide shaft, 5a, 5b ... Printing head,
6a, 6b ... Ink ribbon cartridge, 7 ... Main control unit, 8a, 8b ... Sub control unit, 9a, 9b ... Head drive circuit, 10
a, 10b …… Motor drive circuit, 11a, 11b …… Space motor, 12 …… Motor drive circuit, 13 …… Line feed motor, 14 …… Control circuit, 15,16a, 16b, 17 …… Signal line, 18 ...
… Optical sensor, 19… Pinion, 20… Rack, 21… Frame, 22… Flexible cable

Claims (3)

[Claims] 1. A multi-head printer having first and second print heads arranged along a spacing direction, wherein a first carriage having the first print head and a second print head are provided. A second carriage mounted on the first carriage, a first rotary motor mounted on the first carriage, a second rotary motor mounted on the second carriage, and a first rotary motor on the first rotary motor. Connected to the second rotary motor, which is connected to the first rotary motor and which converts the rotation into a linear motion to move the first print head together with the first carriage in the spacing direction. Second power conversion means for converting the rotation into a linear motion to move the second print head together with the second carriage in the spacing direction, the first rotary motor and the first A first sub-control unit that drives the print head in synchronism; a second sub-control unit that drives the second rotary motor and the second print head in synchronism; Data of 1 line is divided so that the first print head and the second print head share and print the data, and the divided data is output to the first and second sub-control units. A multi-head printer having a main controller. 2. The first rotary motor and the second rotary motor each have encoders for detecting the positions of the first print head and the second print head, respectively. A multi-head printer according to claim 1. 3. The first power conversion means and the second power conversion means mesh with pinions provided on respective rotary shafts of the first rotary motor and the second rotary motor, and mesh with both pinions. The multi-head printer according to claim 1, wherein the multi-head printer comprises a first carriage and a rack extending in a moving direction of the second carriage.