JP2007216451A - Method for judging viscosity of ink and recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep recording performance with a high quality and being homogeneous of a recording apparatus by judging viscosity increasing condition of ink at a low cost, and making interchanging of an ink cartridge, injection of a diluting liquid, and agitation appropriate. <P>SOLUTION: A test pattern for judging the viscosity of the ink is made to be a belt-like pattern intersecting at right angles to the paper conveying direction. Before recording the test pattern is started, a recording head is held under a condition exposing to the atmosphere in accordance with temperature and humidity condition in the recording apparatus. Then, recording operation is started, and the viscosity increasing condition of the viscosity of the ink can be judged with a lapse of time from an unstable recording just after starting to a condition being stabilized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for determining the viscosity of ink used in ink jet recording, and a recording apparatus including a test pattern for determining ink viscosity.

  2. Description of the Related Art Inkjet recording apparatuses (inkjet printers) that form images by ejecting ink (ink droplets) onto a recording medium from ink ejection ports of a plurality of nozzles formed on a recording head (printing head) are widely used.

  Among the above-described recording apparatuses, there is a recycle type in which the ink discharged from the nozzles during a known recovery operation is used again for image recording. In this type of recording apparatus, moisture may evaporate from the ink during recycling and the colorant concentration of the ink may increase to thicken the ink (the viscosity of the ink may increase), so that the desired image quality may not be obtained. There is.

Therefore, for example, a technique is known in which the amount of ink diluent is obtained from the difference between the assumed ink remaining amount and the actual ink remaining amount, and the viscosity of the ink is adjusted by adding the ink diluent to prevent deterioration in recording performance and image quality. ing.
(For example, see Patent Document 1)
As is well known, during a recovery operation, the face surface (the surface on which a plurality of ink discharge ports are formed) is closed with a rubber cap, and ink is discharged from the ink discharge port to this cap. The ink discharged to the cap is collected and reused.

  In particular, during printing standby or when the power is turned off for a long time, the ink viscosity increases because water is evaporated from the ink discharged to the cap. Ink whose viscosity has suddenly increased (hereinafter referred to as thickening) has a sudden change in the ejection characteristics of the recording head, and cannot be ejected under normal driving conditions, causing disconnection or scorching of the heater section of the recording head.

  In particular, when pigment ink is used, a pigment that easily aggregates in the ink recovery path may block the ink flow path, or cause a printing failure that cannot be recovered by clogging the nozzles of the recording head.

  As a means for detecting ink thickening, there is known a technique in which an ink viscosity detection sensor and a camera for observing ink are installed in the main body of the apparatus. However, since a sensor and a camera are installed, the cost increases.

Japanese Patent Laid-Open No. 2001-010087

  In view of the above circumstances, the present invention can determine the thickening state of ink at a low cost, and make the recording device high-quality and more uniform recording performance by appropriately replacing the ink cartridge, injecting the diluent, and stirring. The purpose is to maintain.

  The test pattern for determining the ink viscosity is a belt-like pattern perpendicular to the paper transport direction, and the recording head is kept exposed to the atmosphere for a time according to the temperature and humidity conditions inside the recording apparatus. It was made possible to judge the increase in ink viscosity from the stable recording to the stabilization.

  By implementing the present invention, the ink used in the recording apparatus can be used effectively. In particular, in a recording apparatus capable of recycling the ink used for the cleaning and recovery operations of the recording head, there is an effect of maintaining a high-quality and more uniform recording performance.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a front view showing an example of a recording apparatus capable of executing an ink viscosity determination test according to the present invention.

  The recording apparatus 100 is connected to a host PC (personal computer) (not shown) and receives a recording command and image data. In the recording apparatus 100, four recording heads 102, 103, 104, and 105 are arranged in parallel in the conveyance direction of the recording medium (here, roll paper P).

Black, cyan, magenta, and yellow inks are ejected from the recording heads 102, 103, 104, and 105, respectively. Ink is exchangeable from each of the replaceable ink cartridges 106 (black), 107 (cyan), 108 (magenta), and ink cartridge 109 (yellow) via the corresponding sub-tanks 116, 117, 118, and 119. 102, 103, 104, and 105.
The diluting liquid tank 307 is for injecting diluting liquid into the sub-tanks 106 to 109 of the respective colors, which will be described later.

  The recording heads 102, 103, 104, and 105 are so-called line heads, and the recording width extends in the depth direction of the roll paper P in FIG. The maximum recording width of each recording head is designed to be slightly wider than the width of the roll paper P. During the recording operation, these recording heads are stationary at the recording position.

  In order to maintain stable recording performance of the recording heads 102, 103, 104, and 105, recovery units (capping units) 112, 113, 114, and 115 corresponding to the respective recording heads are provided.

  The recovery unit of FIG. 1 shows six colors, but two of these are spare mechanisms when a recording head is added. The recovery units 112 to 115 are configured by known wiper blades, caps, and the like.

  When forming an image on the roll paper P, after the recording start position of the roll paper P being conveyed reaches below the black recording head 102, the recording head is based on the recording data (image information). Black ink is selectively ejected from 102 (black). Similarly, color recording is performed by ejecting ink of each color in the order of the recording head 103 (cyan), the recording head 104 (magenta), and the recording head 105 (yellow).

  FIG. 2 is an electrical block diagram of the recording apparatus 100 embodying the present invention.

  Recording data and commands transmitted from the host PC 200 are received by the CPU 202 via the interface controller 201. The CPU 202 is an arithmetic processing unit that performs overall control such as reception of recording data of the printer 100, recording operation, and handling of the roll paper P. The interface controller 201 may include another independent CPU.

  In the CPU 202, after analyzing the received command, the image data of each color component of the recording data is rendered as a bitmap on the image memory 207. As an operation process before recording, the capping motor 215 and the head up / down motor 214 are mutually driven via the output port 220 and the motor drive unit 221, and the recording heads 102 to 105 are moved from the cap positions of the capping mechanisms 112 to 115, respectively. Move to the recording position.

  Subsequently, the servo logic for driving the paper feed motor 216 for feeding out the roll paper P through the output port 220 and the motor drive unit 221 and for starting the transport motor 212 for transporting the roll paper P, etc. An instruction speed value corresponding to a desired conveyance speed is written in the circuit 210. A rotary encoder 213 is coupled to the motor shaft of the transport motor 212 or a transport roller shaft (not shown), and a pulse synchronized with the movement of the roll paper P is output.

  A plurality of labels temporarily attached to the paper P are fed out and the leading edge of the label arrived by the leading edge detection sensor 120 is detected, and the U / D (Up / Down) in the servo logic circuit 210 is detected by the output of the rotary encoder 213 described above. ) A counter (not shown) can accurately indicate the latest position of the label.

  Further, the servo logic circuit 210 obtains the latest transport speed of the transported label from a value proportional to the reciprocal of the pulse interval of the output pulse from the rotary encoder 213, and performs feedback control so as to obtain the above indicated speed value.

  Since the cut-out timing for starting the recording can be determined from the above, in synchronization with the conveyance of the roll paper P, the CPU 202 sequentially reads out the corresponding color recording data from the image memory 207, and passes through the recording head control circuit 219. The recording data is transferred to the recording heads 102 to 105.

  A temperature sensor 209 is built in each of the recording heads 102 to 105, and the CPU 202 can sequentially read through the A / D converter 208.

  Further, the output of the temperature / humidity sensor 210 for detecting the temperature and humidity inside the recording apparatus 100 can also be read out via the A / D converter 208.

  Further, a timer (not shown) for measuring the exposure time described later is incorporated in the CPU 202.

  The operation of the CPU 202 is executed based on a processing program stored in the program ROM 203.

  A test recording procedure for determining ink viscosity, which will be described later, is also stored in the program ROM 203. The ink viscosity determination test may be appropriately determined by the user depending on the quality of the recorded image, but is executed when a predetermined period (for example, one month) has elapsed after the recording heads 102 to 105 have been replaced.

  In addition, the CPU 202 uses a work RAM 204 as a working memory. During the cleaning or recovery operation of the recording heads 102 to 105, the CPU 202 drives the pump motor 217 via the output port 220 and the motor driving unit 221 and controls ink pressurization and suction.

  Parameters unique to the recording apparatus 100, such as an electrical correction value for finely correcting a mechanical recording position shift resulting from the attachment of the recording heads 102 to 105, are stored in the EEPROM 205, which is a nonvolatile memory.

  The instruction of test recording for viscosity determination according to the present invention is normally performed from the host PC 200, but can also be executed by an operation key on the operation panel 121 or an input from a display.

  FIG. 3 is a schematic diagram showing an ink supply path of the recording apparatus 100 of the present invention, and shows a state where ink is supplied from a replaceable ink tank to a sub tank. Each component will be described representatively when the ink color is black, but the same applies to other ink colors.

  When the supply valve 303 is opened and the pump 304 is driven, the ink 301 in the ink tank 106 is supplied to the sub tank 116 via the filter 302, the supply valve 303, and the pump 304, and the ink remaining amount detection sensor 305 detects the full tank. If it does not reach the full tank within a predetermined time, it is determined that the ink 301 in the ink tank 106 has become empty, and an ink tank replacement request can be displayed.

  The diluent tank 307 for storing the pure water 308 to which the antifungal agent is added will be described later.

  Next, FIG. 4 shows a state during the recording operation. The ink color is typically described as black, but the other ink colors are substantially the same.

  While the air communication valve 306 of the sub tank 116 is open, an image is formed on the paper P from a number of nozzles of the recording head 102, but the liquid chamber 404 inside the recording head 102 is negatively charged according to the amount of ink ejected. Pressure is generated, and the ink moves from the sub tank 116 through the filters 402 and 403.

  Next, FIG. 5 shows a state where the recording head 102 has entered a recovery operation for maintaining or recovering sound recording performance. The recovery valve 401 is closed first, and the recording head 102 returns to the state capped by the capping mechanism 105. When the pressurizing pump 501 is driven, the ink in the sub tank 116 moves through the filter 403, but since the recovery valve 401 is closed, the ink in the liquid chamber 404 is rapidly pressurized and is discharged from each nozzle of the recording head 102. Since a relatively large amount of ink is forcibly discharged instantaneously, the nozzle is restored to a healthy state.

  The forcibly discharged ink tries to temporarily accumulate in the ink reservoir 405 of the capping mechanism 105. However, since the recycle valve 505 is opened in advance and the pump 304 is operating, the ink is discharged from the discharge port 503 to the recycle valve 505 to the pump 304. In this way, it is collected in the sub tank 116 and recycled. Accordingly, the ink in the recording apparatus gradually evaporates and the ink density tends to increase, so that dilution is necessary.

  FIG. 6 illustrates a method for injecting the diluent.

  First, the recycle valve 505 on the return path from the capping mechanism 105 side is closed, and the valve 601 on the side of the diluent tank 307 containing the diluent 308 is opened.

  Then, the pump 304 is driven, and the diluent 308 is injected into the sub tank 116 through the path of the valve 601 to the pump 304. At this time, the stirring blade 602 inside the sub tank 116 is rotated in advance to average the ink density inside.

  For example, the diluent 308 is obtained by adding a fungicide to pure water, and can be used not only for the black ink shown in this embodiment but also for other ink colors.

  In addition to the recovery operation by pressurization described with reference to FIG. 5, there is also a simple recovery operation in which ink is preliminarily discharged from the ink discharge port. The execution conditions of this preliminary discharge (preliminary discharge) will be described with reference to FIG.

The temperature and humidity in FIG. 7-1 are measured by a temperature / humidity sensor 126 (see FIG. 2) inside the recording apparatus. The time (seconds) entered in the table shows an example of an allowable time in which stable recording performance is maintained even if the nozzle surface of the recording head is removed from the capping mechanism and exposed to the atmosphere. Is 10 to 15 [° C.] and the internal humidity is in the range of 50 to 70 [% RH], the allowable time is 35 seconds. The reasons why these allowable times must be taken into account are mainly as follows.

For example, considering a line head, there may be a nozzle that ejects ink continuously or intermittently depending on an image pattern to be printed, and a nozzle that continues to be in a state where no ejection operation is performed.
The ink in the vicinity of the nozzles ejected at an appropriate frequency is refreshed so that the viscosity is not easily increased. However, in the vicinity of the nozzle that is not used, the thickening of the ink proceeds and the recording tends to become unstable. Since the thickening varies greatly depending on the ambient conditions, it is preferable to have the allowable time in a table format depending on the temperature and humidity as shown in FIG.

  FIG. 7A is stored in the ROM 203 and is used to determine whether or not to perform a preliminary ejection operation during a normal recording operation.

  FIG. 8 is a graph showing the relationship between the water evaporation rate and the viscosity, and the relationship varies depending on the type of ink.

  In the case of the ink used in this embodiment, the ink viscosity allowable range in which the recording operation can be performed is less than 6 [mpa / s], and if the ink is used continuously with a viscosity of 6 [mpa / s] or more, it results from ejection failure. There is a concern of causing an unrecoverable failure due to overheating of the nozzle heater.

  Next, the ink viscosity determination method of the present invention will be described with reference to FIG.

  FIG. 9A shows that recording is started after the nozzle surface of the recording head is removed from the capping mechanism and exposed to the atmosphere for the exposure time shown in the figure under a 25 [° C.] / 60 [% RH] environment. It is a graph which shows the number of discharges required until it stabilizes, and uses ink viscosity as a parameter.

  The horizontal axis is the exposure time (seconds), and the vertical axis is the number of ejections required until the recording is stabilized.

The number of ejections required to obtain a stable recorded image after 100 seconds exposure is
Viscosity 6 [mpa / s]: 3000 [dot]
４ 4 [mpa / s]: 1500 [dot]
〃 2 [mpa / s]: 500 [dot]
It is.

  Accordingly, a case will be described in which, for example, a test image pattern as shown in FIG. 10 is formed by exposing the head for 100 seconds in an environment of 25 [° C.] / 60 [% RH], for example. One line 1001 of the test image pattern is composed of 100 [dots] in the transport direction.

  If an image recording result as shown in FIG. 10-1 is obtained, the internal ink viscosity is as high as 6 [mpa / s] or more, and it is difficult to maintain the image quality as it is. It is necessary to refresh the ink by injecting the diluent.

  If the image recording result as shown in FIG. 10-2 is obtained, the internal ink viscosity is considered to be about 4 [mpa / s]. It is necessary to lower the ink viscosity by injection.

  When an image recording result as shown in FIG. 10-3 is obtained, the internal ink viscosity is considered to be good within 2 [mpa / s], and there is no need for ink replacement or dilution liquid injection.

  In the figure, b is an unstable area at the start of recording, and a is a stable area of recording.

  FIG. 9-2 shows that recording starts after the nozzle surface of the recording head is removed from the capping mechanism and exposed to the atmosphere for the exposure time shown in the drawing under an environment of 15 [° C.] / 10 [% RH]. It is a graph which shows the number of discharges required until it stabilizes, and uses ink viscosity as a parameter.

  The horizontal axis is the exposure time (seconds), and the vertical axis is the number of ejections required until the recording is stabilized.

In this figure, the number of ejections required to obtain a stable recorded image after exposure for 80 seconds is
Viscosity 6 [mpa / s]: 3000 [dot]
４ 4 [mpa / s]: 1500 [dot]
〃 2 [mpa / s]: 500 [dot]
It is.

  Therefore, for example, when the viscosity determination pattern is executed in an environment of 15 [° C.] / 10 [% RH], the exposure time is reduced to 80 seconds and the test image as shown in FIG. 10 is formed as described above. .

  As described above, if an image recording result as shown in FIG. 10-1 is obtained, the internal ink viscosity is as high as 6 [mpa / s] or more, and it is difficult to maintain the image quality as it is. Furthermore, it is necessary to refresh the ink by injecting the diluent.

  Further, if an image recording result as shown in FIG. 10-2 is obtained, the internal ink viscosity is considered to be about 4 [mpa / s]. It is necessary to lower the ink viscosity by injection.

  When an image recording result as shown in FIG. 10-3 is obtained, the internal ink viscosity is considered to be good within 2 [mpa / s], and there is no need for ink replacement or dilution liquid injection.

  FIG. 9-3 shows that the recording is started after the nozzle surface of the recording head is removed from the capping mechanism and exposed to the atmosphere for the exposure time shown in FIG. 9 in an environment of 20 [° C.] / 80 [% RH]. It is a graph which shows the number of discharges required until it stabilizes, and uses ink viscosity as a parameter.

  The horizontal axis is the exposure time (seconds), and the vertical axis is the number of ejections required until the recording is stabilized.

In this figure, since the humidity is high unlike the above two ambient conditions, the number of ejections required for obtaining a stable recorded image after starting a recording after a relatively long exposure time of 240 seconds,
Viscosity 6 [mpa / s]: 3000 [dot]
４ 4 [mpa / s]: 1500 [dot]
〃 2 [mpa / s]: 500 [dot]
And getting results.

  Therefore, for example, when the viscosity determination pattern is executed in an environment of 20 [° C.] / 80 [% RH], the exposure time is increased to 240 seconds and a test image as shown in FIG. 10 is recorded as described above.

  As described above, if an image recording result as shown in FIG. 10-1 is obtained, the internal ink viscosity is as high as 6 [mpa / s] or more, and it is difficult to maintain the image quality as it is. Furthermore, it is necessary to refresh the ink by injecting the diluent.

  Further, if an image recording result as shown in FIG. 10-2 is obtained, the internal ink viscosity is considered to be about 4 [mpa / s]. It is necessary to lower the ink viscosity by injection.

  When an image recording result as shown in FIG. 10-3 is obtained, the internal ink viscosity is considered to be good within 2 [mpa / s], and there is no need for ink replacement or dilution liquid injection.

  Further, as is clear from FIG. 9-3, for ink having an ink viscosity of about 6 [mpa / s], for example, there is data indicating that 1500 [dot] is necessary before a stable image can be formed after exposure for 120 seconds. Since it is obtained in advance, if the result shown in FIG. 10-2 is obtained after exposure for 120 seconds in a 20 [° C.] / 80 [% RH] environment, the viscosity of the ink in use is 6 [mpa / s. ] Can be determined.

  Although it is not possible to determine whether the exposure time is 120 seconds or 4 [mpa / s] or 2 [mpa / s], it is possible to reduce the determination time for thickened ink outside the use limit.

As described above, the exposure time corresponding to the temperature and humidity inside or around the recording apparatus 100 is determined in advance, and the ink viscosity determination test is executed. The ink viscosity determination test method of the present invention can execute a viscosity determination test by previously setting an exposure time corresponding to the type of ink.
The procedure of this ink viscosity determination test method will be described based on the flowchart of FIG.

  The ink viscosity determination test is started when the user presses a viscosity determination test button (not shown) of the recording apparatus 100. A sequence for executing the ink viscosity determination test at regular intervals may be stored in the program ROM 203 (see FIG. 2). First, the CPU 202 of the recording apparatus 100 reads the value of the temperature / humidity sensor 210 (see FIG. 2) and converts it to the temperature and humidity inside the recording apparatus 100 to detect (1101).

  Based on these temperatures and humidity, the exposure time τ is determined from FIG. 7-2 (1102), and the recording heads 102 to 105 capped at the standby position are moved to the recording position (1103). Then, the state in which the recording heads 102 to 105 are exposed to the atmosphere is maintained for the exposure time τ (1104). When this exposure time has elapsed (1104-Yes), a test pattern for ink viscosity determination is recorded (1105).

  The temperature / humidity to exposure time τ conversion table (FIG. 7B) inside the recording apparatus 100 is stored in the ROM 203.

  In the above embodiment, only one table shown in FIG. 7-2 is used, but this table varies depending on the ink type (for example, pigment ink, dye ink) or the color of the ink used. If the exposure time differs greatly, you should have a table independently for each ink type and color. In this case, the ink viscosity determination tests of the recording head (K) 102, the recording head (C) 103, the recording head (M) 104, and the recording head (Y) 105 are executed in a time division manner.

  FIG. 7-3 is an exposure time table before the start of the ink viscosity determination test pattern according to another embodiment of the present invention.

  When determining the ink (for example, black) that seems to be thickened, the exposure time is fixed (for example, 10 seconds), and the number of dots in the conveyance direction of the image to be recorded is determined by the temperature and humidity conditions inside the recording apparatus 100. It is variable.

  In this case, if the number of dots shown in FIG. 7-3 is unstable in the vicinity of the rear end of the image, the viscosity of the ink has reached 6.0 [mpa / s], and discharge failure is observed at the rear end of the image. If not, the viscosity of the ink is less than 6.0 [mpa / s], and it can be determined that the ink is in a usable region.

  According to FIG. 7-3, when the inside of the recording apparatus 100 is, for example, 20 [° C.] / 60 [% RH], the head exposure time is 10 seconds, and the continuous recording dot number of the test pattern is automatically 300 [dot]. Selected. The test pattern selected according to the color or type of ink can also have an independent table.

  Since the ink viscosity determination pattern according to the present invention varies in ejection suitability for each nozzle, a determination pattern using all nozzles is preferable in order to improve determination reliability.

  As a result of the ink viscosity determination according to the present invention, when the ink viscosity exceeds 6.0 [mpa / s] and refresh is performed by supplying ink from a new ink cartridge, the operation flow of the CPU 202 will be described with reference to FIG.

  When it is detected that a new ink cartridge has been replaced (1201-Yes), first, ink supply from the cartridge to the sub tank is started by the method already described (FIG. 3) (1202), and stirring in the sub tank is performed. The blade 602 is also turned on by an actuator (not shown) (1203). When the sub tank is detected to be full (1204—Yes), the ink supply is stopped (1207). If the sub-tank does not become full even after a predetermined time has elapsed (1205-Yes), it is determined that the ink cartridge has become empty, and an alarm requesting that a new cartridge be replaced is sent (1206).

  When the ink supply is completed, a predetermined amount of the diluted solution is injected from the diluted solution tank (1208). Injected after detection of the full tank in the sub tank, but at least, it is designed so that ink overflow does not occur from the sub tank when the dilution liquid is injected. Subsequently, in order to refresh the ink path between the sub tank and the recording head and the ink in the liquid chamber of the recording head, the pump 501 is driven to start the ink circulation operation (12020). At this time, the recovery valve 401 is kept open to form a return path from the recording head to the sub tank. When the ink is circulated, pressure inside the recording head is applied, and a small amount of ink is discharged from the nozzles to the ink reservoir 502 of the recovery mechanism 105. The recycling pump 304 that collects and reuses the ink is also turned on (1210).

  When the predetermined time has elapsed (1211-Yes), the ink circulation is ended (1212). When a predetermined time further elapses (1213-Yes), the recycling system pump is also turned off (1214), and finally the rotation of the stirring blade is stopped (1215) to complete the ink refresh operation.

  In some cases, the ink cartridge is not replaced based on the result of the determination of the ink viscosity according to the present invention, and only the diluted solution is injected, and the ink viscosity is reduced and optimized. However, the method is almost included in the description of FIG. It is omitted here.

  The recording apparatus of the present invention can remarkably improve the operation reliability for maintaining high image quality by using it for a high-speed line printer that can recycle ink, such as a high-speed and heavy-duty label printer and a large color printer. .

It is a figure which shows typically the recording device which implemented this invention. 1 is an electrical block diagram of a recording apparatus embodying the present invention. It is a schematic diagram which shows ink replenishment to a sub tank. FIG. 6 is a schematic diagram illustrating an ink flow during a recording operation. FIG. 5 is a schematic diagram illustrating a pressure recovery operation of the recording head. It is a schematic diagram which shows the injection method of a dilution liquid. It is a figure which shows the pre-discharge interval with respect to temperature / humidity, the exposure time at the time of a test pattern, and the continuous dot number of the test pattern by another Example. It is a figure which shows the ink viscosity change with respect to a water evaporation rate. It is a figure of the number of required dots from the start of recording to the stability with respect to the exposure time. It is a figure which shows the recording result which can be estimated with the check pattern for ink viscosity determination. It is a flowchart at the time of execution of an ink viscosity determination pattern. It is a flowchart in the case of ink refresh.

Explanation of symbols

100 Recording Device 102 Recording Head (K)
103 Recording head (C)
104 Recording head (M)
105 Recording head (Y)
106 Ink cartridge (K)
107 Ink cartridge (C)
108 Ink cartridge (M)
109 Ink cartridge (Y)
112 Recovery Unit (K)
113 Recovery Unit (C)
114 Recovery Unit (M)
115 Recovery Unit (Y)
116 Sub tank (K)
117 Sub tank (C)
118 Sub tank (M)
119 Sub tank (Y)
120 Tip detection sensor 121 Operation panel

200 host PC
202 CPU
203 ROM
208 AD converter 210 Temperature / humidity sensor

304 Pump 307 Diluent tank 308 Diluent

505 Recycling valve

601 Valve 602 Agitation blade

Claims (8)

A recording head for recording an image by discharging ink onto a sheet to be conveyed; a capping mechanism for capping the recording head;
Temperature and humidity detection means for detecting temperature and humidity in the vicinity of the recording head;
Test pattern operation instruction means for instructing the operation of a strip-shaped test pattern perpendicular to the transport direction;
Based on the detection result of the temperature / humidity detection means, the recording head is removed from the capping mechanism, and by the start of recording of the test pattern,
A waiting time setting means for setting a waiting time,
Ink viscosity determination method for recording apparatus. When the ink is replaced based on the result of the ink viscosity determination method, the ink is supplied from the first ink tank to the second ink tank and is stirred by the stirring means in the second ink tank. To
A recording apparatus comprising the ink viscosity determination method according to claim 1. After supplying ink from the first ink tank to the second ink tank, a predetermined amount of dilution liquid is injected from the third ink tank to the second ink tank, and the second ink tank and the recording head are also injected. And further comprising an ink circulation means for circulating ink between and
The recording apparatus according to claim 2. An ink recycling means for collecting ink from the capping means to the second ink tank while the ink circulation means is in operation is further provided.
The recording apparatus according to claim 2. Based on the result of the ink viscosity determination method, a diluent is injected from the third ink tank into the second ink tank, and is stirred by the stirring means in the second ink tank.
The recording apparatus according to claim 2. The dilution liquid contains pure water and a fungicide,
The recording apparatus according to claim 5. A recording head for recording an image by discharging ink onto a sheet to be conveyed; a capping mechanism for capping the recording head;
In a recording apparatus comprising test pattern recording instruction means for instructing recording of a test pattern based on predetermined image data,
The predetermined image data is a belt-like pattern perpendicular to the conveyance direction, and the test pattern recording instruction unit has a predetermined waiting time until the recording head is released from the cap state by the capping mechanism and starts recording of the image data. A recording apparatus, further comprising a waiting time setting means for setting. Further comprising temperature and humidity detection means for detecting temperature and humidity in the vicinity of the recording head;
The recording apparatus according to claim 7, wherein the waiting time setting unit sets a waiting time based on a detection result of the temperature and humidity detection unit.

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