JP3156423B2 - Ink jet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus.

[0002]

2. Description of the Related Art Bubbles at an ink discharge portion in ink jet recording adversely affect the particle diameter and flying speed of an ejected ink droplet, and in the worst case, the ink droplet cannot be ejected, resulting in disturbance in recording quality. . In ink jet recording in which ink droplets of a plurality of colors are ejected from a print head, if the particle size of the ejected ink droplets changes, color reproducibility due to the overlap of the inks of the plurality of colors cannot be guaranteed. therefore,
Inflow of bubbles into the ink ejection section due to ink end must be avoided as much as possible. In an ink jet recording apparatus using a plurality of colors of ink, it is necessary to detect the ink end of each color ink cartridge.

When an ink cartridge containing inks of each color is mounted on a carriage in order to eject inks of a plurality of colors, a plurality of ink end detection terminals correspond to each color.

In detecting the ink end of a water-soluble ink impregnated in a foam inside an ink cartridge, an electrode is provided in the foam, and a voltage pulse is input so that the resistance value of the ink changes according to the remaining amount of the ink. Is electrically detected.

In order to detect the ink end from the main board outside the carriage by a voltage pulse, a signal line for connecting each ink end terminal to a detection unit on the main board is required. The number of signal lines of the connection cable tended to increase. In addition, when each ink end detection unit is independently configured, there are a plurality of detection units having the same configuration, so that cost efficiency is reduced and a reduction in substrate area cannot be expected.

In Japanese Patent Application Laid-Open No. 4-122649, in order to solve the above-mentioned problem, one ink end detection unit is used, and the order of information to be detected in the selection circuit is written by MPU for a plurality of information on the carriage. It is stated that the number of signal lines can be reduced by detecting in a time-division manner.

[0007]

However, when the output of the selection circuit for designating the order of the detection information is a decode signal, the effect of reducing the number of signals is reduced when the detection information is relatively small. Further, the connection between the MPU and the selection circuit requires many wirings. Therefore, the effect of reducing the number of signal lines of the connection cable is small when the selection circuit and the switching circuit are mounted on the carriage, or when only the switching circuit is mounted on the carriage.

When an ink end detection method using a pulse voltage is applied to ink cartridges of a plurality of colors, a time corresponding to a detection pulse width is required for each color, and the ink end detection during a printing operation is an independent task. If performed, the throughput will be reduced.

[0009]

An ink jet recording apparatus according to the present invention is an ink jet recording apparatus using a plurality of color inks, comprising: an ink cartridge; an ink end detecting section to which a plurality of ink end terminals are connected; A cartridge selection unit for switching the ink end terminal on the carriage, and an ink end conversion unit for converting the output of the ink end detection unit outside the carriage, and the detection pulse is necessary for ink end detection. It is characterized by comprising a plurality of pulse trains having a pulse width time. Further, the detection pulse is output by a detection trigger synchronized with a phase excitation trigger of the paper feed motor. Further, the detection trigger can be switched between a phase excitation trigger and a software trigger of the paper feed motor. Further, the ink end conversion unit has a data holding unit for holding a plurality of ink end detection results.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment shown in the drawings will be described below.

FIG. 2 is a perspective view showing an embodiment of the configuration of the ink jet recording apparatus according to the present invention, including a partially broken section.

FIG. 3 is a side view for explaining one embodiment of the inside of the carriage 21 and the ink cartridge 25 in the present invention.

The ink cartridges 25 to 28 are mounted on the carriage 21 together with the print head 24. Each of the ink cartridges 25 to 28 contains ink of a different color. The terminal covers 35 to 38 protect the ink end terminals 1 to 4 of the ink cartridges 25 to 28. The carriage board 18 is mounted inside the carriage 21 and is electrically connected to a main board 19 outside the carriage 21 by a connection cable 20. The print medium 29 is wound around the platen 23 and sent by driving the paper feed motor 22.

The inside of the ink cartridge 25 is filled with a foam 39. The water-soluble ink impregnated in the foam 39 accumulates in the ink chamber 42 through the filter 40 and is supplied to the print head 24 through the ink passage 43 penetrating the rubber stopper 41. Ink end terminals 1-a, 1-
b is arranged so as to be in contact with the foam 39 and is partially exposed on the end face of the ink cartridge 25. The ink end connectors 44-a and 44-b are respectively connected to the ink end terminals 1-.
a, 1-b, and connected to the carriage substrate 18. The ink cartridge 25 is detachable from the carriage 21, and the ink cartridges 26 to 2
8 has a similar structure.

FIG. 4 is a circuit diagram showing an embodiment of the configuration of the ink end detecting section 6 according to the present invention.

The ink end terminals 1 to 4 are respectively Tr1 to T
Connected to r4 and R5. Ink end signal 15
, A voltage divided by R and any one of the resistance values R1 to R4 indicated by the ink end terminals 1 to 4 is output. Tr1
Any one of .about.Tr4 is selectively turned on by the transistor drive signals 16-1 to 16-4, and determines an ink end terminal for performing ink end detection.

FIG. 5 is a circuit diagram showing an embodiment of the configuration of the cartridge selection unit 5 for switching the ink cartridge for detecting the ink end in the present invention.

The detection pulse 14 is composed of a pulse train having a time width necessary for detecting the ink end. The detection pulse 14 is input to IC2 via IC1 and counted. The IC3 receives the output of the IC2 and sets any one of Y0 to Y3 to a low level. IC4 to IC7 are each IC3
Of the detection pulses 14 and outputs transistor drive signals 16-1 to 16-4. At this time, any one of the transistor drive signals 16-1 to 16-4 is at a low level, and a plurality of transistor drive signals are not at a low level at the same time. That is, the transistor drive signal 16-1 goes low at the first pulse of the detection pulse 14, and the transistor drive signals 16-2, 16-3, 16-4 go low at the second, third, and fourth pulses, respectively. .

FIG. 6 is a circuit diagram showing an embodiment of the configuration of the ink end converter 8 in the present invention.

The ink end signal 15 output from the ink end detector 6 is input to the A / D converter 30. A
The / D converter 30 outputs data corresponding to the voltage of the ink end signal 15 while the detection pulse 14 is at the low level.
The A / D converter 30 is activated by the rising edge of the detection pulse 14.
Is latched by the latch 31. Following the detection pulse 14, the data is latched in the latch 3.
2, 33 and 34 are sequentially latched. As a result, the latches 31 to 34 latch the ink end detection results by the latest four pulses of the detection pulse 14 and output the results as ink end data 17, respectively.

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention.

The paper feed motor drive unit 9 is driven by a paper feed phase excitation trigger 11 output from the MPU 10 to control the paper feed motor 2.
2 and the paper feed motor 22 is rotated to convey the print medium 29.

The detection pulse generator 7 is triggered by one of the paper feed phase excitation trigger 11 and the software trigger 13 selected by the trigger switching signal 12, and is a detection pulse composed of a pulse train having a time width necessary for detecting the ink end. 14 is output.

The cartridge selector 5 detects the detection pulse 1
By counting four pulses, a transistor drive signal 16 for selecting any one of the ink cartridges 25 to 28 for detecting the ink end is output.

The ink end terminals 1 to 4 of each of the ink cartridges 25 to 28 are connected to an ink end detecting unit 6, and the ink end detecting unit 6 receives a transistor drive signal 16 and selects one of the ink end terminals 1 to 4. Select one to detect the ink end and set the ink end signal 1
5 is output.

The ink end converter 8 sequentially converts and latches the ink end signal 15 with the detection pulse 14 and outputs ink end data 17. The MPU 10 refers to the ink end data 17 as needed.

In this embodiment, the cartridge selector 5
The ink end detector 6 is disposed on a carriage substrate 18 mounted on a carriage 21, and the MPU 10, paper feed motor driver 9, detection pulse generator 7, and ink end converter 8 are mounted on a main substrate 19 outside the carriage 21. Are located.

The detection pulse 14 and the ink end signal 15 are connected to a main board 19 and a carriage board 18 through a connection cable 20.

FIG. 7 is a timing chart showing the operation of this embodiment.

The operation of this embodiment will be described with reference to FIG.

When the trigger switch signal 12 is at a low level indicating that the paper feed phase excitation trigger 11 is valid, and when the paper feed phase excitation trigger 11 is output, the detection pulse generator 12 outputs the detection pulse 14 once. Is set to the low level only for the time necessary for detecting the ink end of the above. At this time, since the outputs QA and QB of the counter IC2 of the cartridge selecting section 5 are at the low level, the decoder IC3 sets the output Y0 to the low level. The IC 7 calculates the logical sum of the output Y0 and the detection pulse 14, and sets the transistor drive signal 16-1 to a low level. On the other hand, transistor drive signals 16-2 to 16
-4 is at the high level.

In response to this, the ink end detector 6 sets the Tr
In order to turn only 1 on, the voltage V1 divided by the resistance value R1 and the resistance R5 of the ink end terminal 1 is output as the ink end signal 15.

A / D converter 30 of ink end converter 8
Outputs the ink end data 1 obtained by converting the ink end signal 15 while the detection pulse 14 is at the low level.

Detection pulse 1 indicating end of ink end detection
The ink end data 1 output from the A / D converter 30 at the rising edge of the signal 4 is latched by the latch 31.

On the other hand, when the detection pulse 14 goes high, the transistor drive signal 16-1 goes high, and Tr1 is turned off. The counter IC2 counts up at the rising edge of the detection pulse 14,
The output QA is at a high level, and QB is at a low level. In response, the decoder IC3 sets the output Y1 to low level.

When the paper feed phase excitation trigger 11 is output again, the detection pulse generator 12 sets the detection pulse 14 to the low level for a time required for one ink end detection.

The IC 6 calculates the logical sum of the output Y1 and the detection pulse 14, and sets only the transistor drive signal 16-2 to a low level.

In response to this, the ink end detector 6 sets the Tr
2 is turned on, the voltage V2 divided by the resistance value R2 of the ink end terminal 2 and the resistance R5 is output as the ink end signal 15.

A / D converter 30 of ink end converter 8
Outputs the ink end data 2 obtained by converting the ink end signal 15 while the detection pulse 14 is at the low level.

Detection pulse 1 indicating end of ink end detection
The ink end data 2 output from the A / D converter 30 at the rising edge of the signal 4 is latched by the latch 31. At the same time, the ink end data 1 latched by the latch 31 is sent to the latch 32 and latched.

This is sequentially repeated, and the ink end terminal 1
Ink end data 1 to 4 corresponding to the respective resistance values of
Are held by the latches 31 to 34.

On the other hand, when the detection pulse 14 is set to the low level four times, the detection pulse generation unit 7 stops its operation, regardless of the presence or absence of the paper feed phase excitation trigger 11, until the ink end data 17 is read by the MPU 17. 1
Keep 4 high. Ink end data 17 is MP
After being read into U10, the detection pulse generator 7 resumes operation and waits for the phase excitation trigger 11.

As described above, the detection pulse 14 is constituted by a plurality of pulse trains having a pulse width time necessary for detecting the ink end, and the cartridge selecting unit 5 and the ink end detecting unit 6 having the counter structure are mounted on the carriage 21. Accordingly, the number of signal lines for ink end detection connected from the carriage substrate 18 to the main substrate 19 can be only two, that is, the detection pulse 14 and the ink end signal 15, and the number of signal lines of the connection cable 20 is reduced. It is possible to greatly reduce.

Printing is completed by detecting the ink end by a trigger synchronized with the paper feed phase excitation trigger 11 →
Even during a printing operation by repeating a series of operations from carriage stop → paper feed → ink end detection → printing start,
The task time required for detecting the ink end is determined by latches 31 to 3
Ink end data 1 to 4 held in MPU 4
Since the reading is completed only by reading the data in step 10, a decrease in throughput can be avoided.

The paper feed phase excitation trigger 11 is output and the paper feed is started when printing is completed and the carriage 21 is stopped, and the ink inside the ink cartridges 25 to 28 on the carriage 21 is stable. In this state, the ink end detection is performed, so that a stable output of the ink end signal 15 is obtained.

Further, in this embodiment, the paper feed phase excitation trigger 11 is used as an example of the detection trigger synchronized with the phase excitation trigger of the paper feed motor.
When the print operation is completed → paper feed start → carriage stop → paper feed end → ink end detection → print start, when paper feed operation and carriage stop processing are overlapped, the first paper feed phase excitation trigger By using a signal delayed from the start of paper feeding by the time of carriage stop for 11 as a detection trigger, ink end detection can be performed in a state where the ink inside the ink cartridges 25 to 28 is stable.

In a paper feed operation without printing (supply and discharge of a print medium, etc.), if the software trigger 13 is enabled by setting the trigger switching signal 12 to a high level, even if the paper feed phase excitation pulse 11 is output. Unless the software trigger 13 is output, the detection pulse 14 does not become low level, and the ink end detection is not performed.

Further, the detection pulse 14 is formed into a plurality of pulse trains having a pulse width time required for ink end detection, and the cartridge selection circuit 5 and the ink end detection unit 6 are mounted on the carriage 21 so that the carriage substrate 18
Therefore, there are only two signal lines related to ink end detection, which are connected to the main board 19, including the ink end signal 15 and the detection pulse 14.

When ink is sucked from the print head 24 by ink suction means (not shown), the amount of ink consumed per time is much larger than the amount of ink consumed during the printing operation. For this reason, it is necessary to always monitor the ink end during the ink suction, and to stop the ink suction operation when the ink end state is detected to prevent bubbles from flowing into the print head 24. As long as the paper feed motor 22 is not the driving source of the ink suction means, the paper feed motor 22 is in a non-operation state during the ink suction operation.

In the present embodiment, the detection of the ink end during the ink suction operation is performed by setting the trigger switching signal 12 to the high level and activating the detection pulse generator 7 by the software trigger 13. The MPU 10 outputs the software trigger 13 four times while sucking the ink, and reads the ink end data 1 to 4 held in the latches 31 to 34 when the four ink end detections are completed. When the ink end state is detected, the ink suction operation is immediately stopped. When the ink end state is not detected, the software trigger 13 is output again and the ink suction operation is continued while monitoring the ink end.

As described above, the trigger change signal 12 causes the paper feed phase excitation trigger 11 and the software trigger 13
Is switched to perform the ink end detection, it is possible to detect the ink end in accordance with the operation state of the ink jet recording apparatus.

In this embodiment, an example has been described in which one ink end detection is performed for one pulse of the paper feed phase excitation trigger 11 or the software trigger 13.
If the configuration of the detection pulse generator 7 is such that the detection pulse 14 is set to the low level four times by one trigger pulse, it is possible to continuously execute the ink end detection operation four times.

[0053]

According to the present invention, the detection pulse is composed of a plurality of pulse trains having a pulse width time necessary for detecting the ink end, so that the number of signal lines for detecting the ink end connected from the carriage substrate to the main substrate can be reduced. And an ink end signal, and the number of signal lines of the connection cable can be greatly reduced.

By detecting the ink end by a detection trigger synchronized with the phase excitation signal of the paper feed motor, the ink inside the cartridge can be detected in a stable state even during the printing operation, and the processing time for the ink end detection is reduced. It becomes unnecessary.

When it is necessary to constantly monitor the ink end, the detection trigger is switched to the software trigger to detect the ink end, so that the ink end can be detected in accordance with the operation status of the ink jet recording apparatus.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an embodiment of an inkjet recording apparatus according to the present invention.

FIG. 2 is a perspective view showing an embodiment of the ink jet recording apparatus according to the present invention, including a partially broken section.

FIG. 3 is a side view illustrating the inside of an embodiment of the carriage and the ink cartridge of the ink jet recording apparatus according to the present invention.

FIG. 4 is a circuit diagram showing an embodiment of an ink end detection unit of the ink jet recording apparatus according to the present invention.

FIG. 5 is a circuit diagram showing an embodiment of a cartridge selection unit of the ink jet recording apparatus according to the present invention.

FIG. 6 is a circuit diagram showing one embodiment of an ink end conversion unit of the ink jet recording apparatus according to the present invention.

FIG. 7 is a timing chart showing the operation of an embodiment of the ink jet recording apparatus according to the present invention.

[Explanation of symbols]

 1-4 Ink end terminal 5 ... Cartridge selection unit 6 ... Ink end detection unit 7 ... Detection pulse generation unit 8 ... Ink end conversion unit 9 ... Paper feed motor drive unit 10 ... MPU 11 ... Paper feed phase excitation trigger 12 ... Trigger Switching signal 13 Software trigger 14 Detection pulse 15 Ink end signal 16 Transistor drive signal 17 Ink end data 18 Carriage board 19 Main board 20 Connection cable 21 Carriage 22 Paper feed motor 23 Platen 24 Print head 25-28 Ink cartridge 29 Print medium 30 A / D converter 31-34 Latch 35-38 Terminal cover 39 Form 40 Filter 41 Rubber plug 42 Ink chamber 43 Ink passage 44 Ink end connector

Claims (4)

(57) [Claims] 1. An ink jet recording apparatus using a plurality of color inks, comprising: an ink cartridge; an ink end detection unit to which a plurality of ink end terminals are connected; and a cartridge selection unit for switching the ink end terminals by a detection pulse. An ink end conversion unit for converting the output of the ink end detection unit, which is provided on the carriage, is provided outside the carriage, and the detection pulse includes a plurality of pulse trains having a pulse width time required for ink end detection. Characteristic inkjet recording device. 2. An ink jet recording apparatus according to claim 1, wherein said detection pulse is output by a detection trigger synchronized with a phase excitation trigger of a paper feed motor. 3. The ink jet recording apparatus according to claim 2, wherein the detection trigger is switched between a phase excitation trigger and a software trigger of the paper feed motor. 4. The ink jet recording apparatus according to claim 1, wherein said ink end conversion section has a data holding section for holding a plurality of ink end detection results.