JPH10217493A - Cleaning device and ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effect optimum cleaning based on the ambient temperature by a method wherein ambient temperature is detected and conditions upon effecting the cleaning are set based on the detecting result of the ambient temperature. SOLUTION: When a print head 3 is at a maintenance position, the surface of the print head 3 provided with a nozzle is brought into close contact with a suction cap 16 and a pulse voltage for flying ink is impressed on the print head 3 while sucking air by a piston pump 17 to discharge ink and effect self purge. By this method, bubbles, dust and the like which are adhered to the peripheral rim of the nozzle and affecting on printing are removed. In this case, the time for which the maximum amplitude of the pulse voltage impressed to drive the piezoelectric element of the print head 3 upon the self purge is kept is increased or decreased in accordance with the decrease or increase of the ambient temperature considering that the viscosity of the ink is increased and cleaning of the ink sludge becomes hard by the reduction of the ambient temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus for a recording head, and more particularly to a cleaning apparatus for a recording head of an ink jet recording apparatus.

[0002]

2. Description of the Related Art Heretofore, there has been an ink jet printer using a piezoelectric element as a print head. In such a printer head, ink in a predetermined closed space is pressurized by distortion of a piezoelectric element driven by application of a voltage. The pressurized ink flies toward the recording sheet as ink droplets from nozzles provided in a predetermined closed space.

[0003] Ink may adhere to the periphery of such a nozzle, or the flying of the ink may become unstable due to contamination caused by drying of the attached ink. Various cleaning devices have been considered for removing these wastes.

[0004]

However, the cleaning effect of the cleaning device against such wastes is affected by the ambient temperature. Such an effect on the cleaning effect is caused by a change in a physical property value or the like of the viscosity of the waste ink adhering to the periphery of the nozzle depending on the ambient temperature.

For example, in the case of performing cleaning for wiping the periphery of the nozzle of the recording head, the number of wipings is set at an ambient temperature of about 25 ° C. when the wiping device is manufactured. However, the ambient temperature assumed as the use environment of the ink jet printer equipped with the cleaning device is, for example, 35 ° C. to 10 ° C., and when the temperature is lowered during this time, among the inks used in the commercially available ink jet printer, In some cases, the viscosity increases 1.5 times or more. 25
Even if cleaning is performed under non-conforming conditions set at an ambient temperature other than around ° C and assuming an ambient temperature of around 25 ° C, the cleaning effect does not increase. In addition, temporarily
If conditions are set so that wiping can be performed reliably even at 0 ° C, unnecessary wiping operations will be repeated at a higher temperature than the normal temperature, and the wiping member will have a longer life in the long term. Will have an effect.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and an object of the present invention is to provide a recording head cleaning apparatus and an ink jet recording apparatus capable of performing optimum cleaning in accordance with the ambient temperature. It is to provide.

[0007]

According to a first aspect of the present invention, there is provided a cleaning apparatus for cleaning a recording head, wherein a detecting means for detecting an ambient temperature and a cleaning condition are set based on the detected ambient temperature. Setting means.

According to the first aspect of the present invention, the ambient temperature is detected, and conditions for performing the cleaning are set based on the result of the detection of the ambient temperature. Thereby, it is possible to perform the optimum cleaning according to the ambient temperature.

According to a second aspect of the present invention, there is provided an ink jet recording apparatus, comprising: a recording head for discharging ink; a cleaning unit for cleaning the recording head; a detecting unit for detecting an ambient temperature; Setting means for setting the cleaning condition based on the condition.

According to the present invention, the ambient temperature is detected, the cleaning condition is set based on the detected ambient temperature, and the recording head is cleaned. This makes it possible to perform optimal cleaning according to the ambient temperature.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an ink jet printer having a suction cap according to a first embodiment of the present invention and an ink jet printer having a wiping device according to a second embodiment of the present invention will be described below. The printer will be described.

First, an ink jet printer having a suction cap according to a first embodiment will be described.

FIG. 1 shows an ink jet printer 1 having a suction cap according to an embodiment of the present invention.
It is a perspective view which shows the outline of a structure of.

[0014] The ink jet printer 1 uses paper or OH.
A recording sheet 2 which is a recording medium such as a P sheet, and a printer head 3 which is an inkjet printer head
A carriage 4 for holding the printer head 3, swinging shafts 5 and 6 for reciprocating the carriage 4 in parallel with the recording surface of the recording sheet 2, and swinging shafts 5 and 6 for the carriage 4.
Drive motor 7 for reciprocating drive along
The timing belt 9 and the idle pulley 8 for changing the rotation of the carriage into a reciprocating motion of the carriage are included.

The ink jet printer 1 includes a platen 10 also serving as a guide plate for guiding the recording sheet 2 along the transport path, a paper pressing plate 11 for pressing the recording sheet 2 between the platen 10 and preventing floating. Recording sheet 2
Roller 12, spur roller 13 for discharging
Paper feed knob 14 for manually conveying recording sheet 2
And a wiping device 15 for wiping unnecessary substances such as ink adhered around the nozzle portion of the printer head 3 and a suction cap 16 for removing these unnecessary substances by suction.

The recording sheet 2 is supplied to a printer head 3 by a sheet feeding device such as a manual feed or cut sheet feeder.
And the platen 10 are sent to the opposite recording unit. At this time, the rotation amount of a paper feed roller (not shown) is controlled, and the conveyance to the recording unit is controlled.

In the printer head 3, a piezoelectric element (PZT) is used as an energy source for flying ink droplets. A voltage is applied to the piezoelectric element, causing distortion. This distortion changes the volume of the channel filled with ink. Due to this change in volume, ink is ejected from nozzles provided in the channel, and recording on the recording sheet 2 is performed.

The carriage 4 is driven by the drive motor 7, the idle pulley 8, and the timing belt 9 to perform main scanning in the direction of the digit of the recording sheet 2 (the direction across the recording sheet 2). Record the image for the line. Each time recording of one line is completed, the recording sheet 2 is fed in the vertical direction and sub-scanned, and the next line is recorded.

The image is recorded on the recording sheet 2 in this manner, and the recording sheet 2 that has passed through the recording section is discharged by a discharge roller 12 disposed downstream of the conveyance direction and a spur roller 13 pressed against the discharge roller 12. Is done.

FIGS. 2 to 4 are diagrams for explaining the configuration of the printer head 3. FIG. 2 is a plan view showing the printer head 3, FIG. 3 is a sectional view taken along line III-III of FIG. 2, and FIG. 4 is a sectional view taken along line IV-IV of FIG.

The printer head 3 has a large-diameter head section 301.
And a small diameter head section 302. The large diameter head portion 301 and the small diameter head portion 302 are
3, the partition wall 304, the diaphragm 305, and the substrate 306 are integrally laminated. Among the plurality of dot diameter ink droplets, a large diameter ink droplet is ejected from the large diameter head portion 301, and a small diameter ink droplet is ejected from the small diameter head portion 302.

The nozzle plate 303 is made of metal, ceramic, or the like, and has a water-repellent coating layer on the surface 320. The surface facing the partition wall 304 is finely processed by Ni electroforming or a photoresist, and the large diameter head portion 301 and the small diameter head portion 302 are provided with a plurality of ink channels 308 for accommodating ink 307 and each ink channel 308, respectively. An ink inlet 311 connected to the ink supply chamber 310 is formed.

As shown in FIG. 3, the ink channels 308 of the large-diameter head portion 301 and the small-diameter head portion 302 have a long groove shape extending in the direction in which the large-diameter head portion 301 and the small-diameter head portion 302 face each other. They are formed in parallel. In addition, the ink supply chamber 310 and the ink channel 30
8 is formed symmetrically with respect to the center line 312,
It is connected to an ink tank (not shown).

A thin film is used for the partition wall 304, and is fixed between the nozzle plate 303 and the diaphragm 305. The partition 304 is fixed in a state where a predetermined tension is applied.

The diaphragm 305 includes a PZT 315. The processing of the diaphragm 305 is first fixed to the substrate 306 with an insulating adhesive, and then the separate grooves 3 are formed by dicer processing.
18 and 319 are formed and divided. In addition, due to this division, each ink channel 30
8, the PZT column 316 located between the adjacent PZTs 315, and the surrounding wall 317 surrounding them are separated.

In the printer head 3 configured as described above, the ink 307 is supplied to the ink supply chamber 310 from an ink tank (not shown) connected to the ink cartridge. The ink 307 in the ink supply chamber 310 is distributed to each ink channel 308 via the ink inlet 311.

From the head ejection driving unit 105 described later, P
A predetermined voltage, which is a print signal, is applied between a common electrode provided at both ends of the ZT 315 and an individual electrode, and the PZT 3
Reference numeral 15 deforms in a direction in which the partition 304 is pushed. PZT315
Is transmitted to the partition wall 304, which pressurizes the ink 307 in the ink channel 308 and causes the nozzle 30
The ink droplet flies toward the recording sheet 2 via 9.

In the present embodiment, a printer head having a large diameter nozzle and a small diameter nozzle is described, but the diameter of the nozzle may be the same.

FIG. 5 is a diagram for explaining the outline of the configuration of the ink cartridge 30 for supplying ink to the printer head 3. FIG. 5A is a front sectional view of the ink cartridge 30, and FIG. 5B is a side view of the ink cartridge 30 as viewed from the supply tube side in FIG. 5A.

The ink cartridge 30 includes the ink chamber 3
3, 35, the ink communication slit 36, and the air communication port 3
7 is included. The ink chambers 33 and 35 are filled with ink, and a filling member 34 such as polyurethane is filled in the ink chamber 33. The ink in the ink cartridge 30 is supplied to the printer head 3 via the ink supply port 32 and the supply pipe 31.

The composition of this ink was 82.5 in water.
% (Hereinafter all weight%), food black dye 3%, diethylene glycol 10%, cyclohexanol 4
%, Surflon S-145 0.2%, and BIT (benz isothiazoline) 0.3%.

FIG. 6 is a block diagram showing the configuration of the control unit of the ink jet printer 1. The control unit of the inkjet printer 1 includes a CPU 101, a RAM 102,
ROM 103, data receiving unit 104, head ejection driving unit 105, head movement driving unit 106, paper feed driving unit 107, cleaning system driving unit 108, cleaning control unit 109, and various sensor units 110 In.

The CPU 101 for controlling the whole executes a program stored in the ROM 103 by using the RAM 102 as necessary. This program includes a head ejection drive unit 105, a head movement drive unit 106, a paper feed drive unit based on image data read from a data reception unit 104, which is connected to a host computer or the like and receives data of an image to be recorded. 107, various sensor units 110
For recording an image on the recording sheet 2 by controlling the
When necessary, a portion for controlling the cleaning system driving unit 108, the cleaning control unit 109, and various sensor units 110 to clean the printer head 3 is included.

Under the control of the CPU 101, the head ejection drive unit 105 drives the PZT 315 of the printer head 3, and the head movement drive unit 106 drives the drive motor 7 that moves the carriage 4 holding the printer head 3 in the column direction.
, And the paper feed drive unit 107 drives the paper feed roller. Further, based on the control of the CPU 101, the cleaning system drive unit 108 and the cleaning control unit 109 drive the wiping device 15, the suction cap 16, and the like to perform cleaning. The various sensor units 110
Includes a temperature sensor required when setting cleaning conditions.

FIG. 7 is a block diagram of a control unit, particularly related to the present invention.
4 is a flowchart illustrating a procedure for controlling a suction cap 16 performed by a PU 101.

First, in S1, it is determined whether a predetermined temperature corresponding to the set cleaning condition is appropriate by comparing with an ambient temperature detected by a temperature sensor.
If the predetermined temperature corresponding to the cleaning condition is appropriate (YES in S1), in S6, the suction cap 16 performs cleaning under the set cleaning condition. If the predetermined temperature corresponding to the cleaning condition is not appropriate (NO in S1), it is determined whether or not printer head 3 is at the maintenance position (in FIG. 1, printer head 3 is in front of suction cap 16). Is determined.

If the printer head 3 is not at the maintenance position (NO at S2), the printer head 3 is returned to the maintenance position at S3, and if the printer head 3 is at the maintenance position (S2). , YE
S), the process is directly shifted to S4.

In S4, the cleaning conditions are adjusted. Next, in S5, it is determined whether or not the predetermined temperature corresponding to the cleaning condition adjusted in S4 for performing printing is appropriate by comparing with the ambient temperature detected by the temperature sensor. If the predetermined temperature corresponding to the cleaning condition is not appropriate (NO in S5), the process proceeds to S4, and if the predetermined temperature corresponding to the cleaning condition is appropriate (YES in S5), In S6, the suction cap 16 performs cleaning under the set cleaning conditions.

FIG. 8 is a perspective view for explaining the outline of the operation of the suction cap 16. At the time of cleaning the printer head 3, the printer head 3 moves in the direction of arrow a along the swing shafts 5 and 6 to reach the front of the suction cap 16 and is in the maintenance position (in FIG. 7). Become.

The self-purge means that the surface of the printer head 3 having the nozzle is brought into close contact with the suction cap 16 while the printer head 3 is in the maintenance position,
Arrow b by piston pump 17 driven by
In other words, while suctioning air in the direction, a pulse voltage for causing the ink to fly to the printer head 3 is applied to discharge the ink. This self-purge removes bubbles, dust, and the like, which affect the printing, and which are mixed in the periphery of the nozzle, so that the periphery of the nozzle of the printer head 3 can be restored to a normal state.

FIG. 9 is a perspective view for explaining the outline of the structure of the suction cap 16, and FIG.
FIG. 5 is a schematic cross-sectional view for explaining the operation of FIG.

The suction cap 16 includes a cap housing 161.
, Cap mounting member 162, rubber cap 16
3, a sponge 164, and a suction hole 165.

The printer head 3 has a nozzle plate 30 having nozzles in a row (in a direction perpendicular to the paper surface) aligned with the arrow c.
Nozzle plate 3 so that the portion B maintains airtightness when the printer head 3 is at the maintenance position.
03 is in close contact with the rubber cap 163.

At the time of self-purging, the ink is ejected from the printer head 3 while the air is sucked from the suction hole 165 in the direction of arrow d by the piston pump 17 (see FIG. 8). This ink is sucked by the air and absorbed by the sponge 164. As a result, air bubbles, dust, and the like that adversely affect the flying of the ink are removed in the ink flow path around the nozzle.

In the present invention, the maximum amplitude or the duration of the maximum amplitude of the pulse voltage applied to drive the piezoelectric element of the printer head 3 during the self-purge is determined.
7. The air suction time or the suction amount by means of 7 is optimized for the ambient temperature.

Hereinafter, the maximum amplitude of the pulse voltage is treated as the self-purging amount, and the duration of the maximum amplitude of the pulse voltage is treated as the self-purging time.

FIG. 11 is a diagram showing the setting of the PZT self-purge time with respect to the ambient temperature. FIG. 11A is a graph showing the setting of the PZT self-purge time with respect to the ambient temperature, and FIG. 11B is a diagram showing the waveform of the pulse voltage applied to the piezoelectric element of the printer head 3 at this time.

As shown in FIG. 11B, the pulse voltage rises with a rise time of 5 μsec, continues the maximum amplitude of 20 V for T [μsec], and has a fall time of 25 μs.
ec is dropped. Considering that the duration T of the maximum amplitude of the pulse voltage is increased in consideration of the fact that the viscosity of the ink increases due to a decrease in the ambient temperature and cleaning becomes difficult,
As shown in (a), the temperature is increased as the ambient temperature decreases. Further, the duration T of the maximum amplitude is reduced with an increase in the ambient temperature, thereby avoiding unnecessary cleaning. As a result, it is possible to perform the optimum cleaning according to the ambient temperature.

FIG. 12 is a view showing the setting of the self-purging amount of PZT with respect to the ambient temperature. FIG. 12A is a graph showing the setting of the self-purging amount of PZT with respect to the ambient temperature, and FIG. 12B is a diagram showing the waveform of the pulse voltage applied to the piezoelectric element of the printer head 3 at this time.

As shown in FIG. 12B, the pulse voltage rises with a rise time of 5 μsec, continues the maximum amplitude of V0 [V] for 10 μsec, and has a fall time of 25 μsec.
It is dropped in sec. The maximum amplitude V of this pulse voltage
In consideration of the fact that the viscosity of the ink increases due to a decrease in the ambient temperature and cleaning becomes difficult, 0 is increased as the ambient temperature decreases, as shown in FIG. Also,
The maximum amplitude is reduced with increasing ambient temperature to avoid unnecessary cleaning. As a result, it is possible to perform the optimum cleaning according to the ambient temperature.

FIG. 13 is a diagram showing the setting of the suction time of the suction cap 16 with respect to the ambient temperature, and FIG. 14 is a diagram showing the setting of the suction amount of the suction cap 16 with respect to the ambient temperature.

The viscosity of the ink increases with a decrease in the ambient temperature, making cleaning difficult. However, by increasing the suction time or the suction amount with the decrease in the ambient temperature as described above, the optimum cleaning is achieved. Can be performed.

The setting for either the self-purging time or the self-purging amount of PZT and the setting for either the suction time or the suction amount of the suction cap are as follows.
They can be used together, or they can be used independently.

Next, an ink jet printer having a wiping device according to a second embodiment will be described.

Regarding an ink jet printer having a wiping device according to the second embodiment, the overall configuration, the configuration of the printer head, the configuration of the control unit, the control procedure, and the like are based on the suction cap of the first embodiment. The wiping device can be used in combination with the suction cap described above.

FIG. 15 is a schematic sectional view for explaining the operation of the wiping device 15. FIG. 15A is a top view around a portion where the wiping device 15 contacts the printer head 3, and FIG. 15B is a side view around a portion where the wiping device 15 contacts the printer head 3.

When cleaning the printer head 3,
Carriage 4 for holding printer head 3 (see FIG. 1)
Moves in the direction of arrow e, reaches the front of the wiping device 15, and is in the maintenance position (in FIG. 7).

The printer head 3 has a nozzle plate 303 having nozzles in rows arranged in the direction of arrow f in the top view (the direction of arrow g in the side view). When the printer head 3 is in the maintenance position, the wiper blade 151 of a part 150 of the wiping device shown in the drawing comes into contact with the surface of the nozzle plate with a predetermined pressure. Further, during the wiping operation, the rotating belt 153 rotates in the direction of arrow h while being held by the upper and lower rotating shafts (only the upper rotating shaft 152 is shown in the figure), and the wiper blade 15
1 rubs the surface of the nozzle plate 303. This removes ink residue, dust, and the like on the nozzle plate surface that adversely affect the flying of the ink.

In the present invention, at the time of wiping, the number of wiping operations performed by the wiping device 15 is optimized with respect to the ambient temperature.

FIG. 16 is a diagram showing the setting of the wiping frequency of the wiping device 15 with respect to the ambient temperature.

The viscosity of the ink increases as the ambient temperature decreases, making cleaning difficult. However, as shown in FIG. 16, the number of wiping operations increases as the ambient temperature decreases. By reducing the number of times of wiping with the rise and avoiding unnecessary cleaning, it is possible to perform optimum cleaning according to the ambient temperature.

In the above description, the value of each cleaning condition is set to be increased as the ambient temperature is decreased, mainly in consideration of the increase in the viscosity of the ink as the ambient temperature is decreased. In consideration of changes in other factors, the value of the cleaning condition depending on the ambient temperature can be set in any way to enhance the cleaning effect.

In the above description, the printer head of an ink jet printer has been particularly described. However, the present invention can be applied to a cleaning device for a recording head of another printer or another recording apparatus.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a configuration of an ink jet printer 1 having a suction cap according to an embodiment of the present invention.

FIG. 2 is a plan view showing the printer head 3 for explaining the configuration of the printer head 3;

FIG. 3 is a sectional view taken along line III-III of FIG. 2 for explaining the configuration of the printer head 3;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3 for explaining the configuration of the printer head 3;

FIG. 5 is a diagram for explaining an outline of a configuration of an ink cartridge 30 that supplies ink to a printer head 3;

FIG. 6 is a block diagram illustrating a configuration of a control unit of the inkjet printer 1.

FIG. 7 is a flow chart showing a procedure for controlling the suction cap 16 performed by the CPU 101 of the control unit, particularly relating to the present invention.

FIG. 8 is a perspective view for explaining the outline of the operation of the suction cap 16;

FIG. 9 is a perspective view for explaining the outline of the configuration of the suction cap 16;

FIG. 10 is a schematic cross-sectional view for explaining the operation of the suction cap 16;

FIG. 11 is a diagram showing a setting of a self-purging time of a suction cap 16 with respect to an ambient temperature.

FIG. 12 is a diagram showing a setting of a self-purging amount of a suction cap 16 with respect to an ambient temperature.

FIG. 13 is a diagram showing the setting of the suction time of the suction cap 16 with respect to the ambient temperature.

FIG. 14 is a diagram showing a setting of a suction amount of a suction cap 16 with respect to an ambient temperature.

FIG. 15 is a schematic cross-sectional view for explaining the operation of the wiping device 15;

FIG. 16 is a diagram showing a setting of the number of times of wiping of the wiping device 15 with respect to an ambient temperature.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink jet printer 3 Printer head 15 Wiping device 16 Suction cap 17 Piston pump 18 Motor 101 CPU 108 Cleaning system drive unit 109 Cleaning control unit 110 Various sensor units 303 Nozzle plate 315 PZT

Claims (2)

[Claims] 1. A cleaning device for cleaning a recording head, comprising: a detecting unit for detecting an ambient temperature; and a setting unit for setting a cleaning condition based on the detected ambient temperature. 2. A recording head for discharging ink, a cleaning unit for cleaning the recording head, a detecting unit for detecting an ambient temperature, and a setting unit for setting a cleaning condition based on the detected ambient temperature. , Inkjet recording device.