JP2831795B2 - Temperature adjusting device, recording head unit having the temperature adjusting device, and recording device equipped with the unit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature adjusting device, a recording head unit, and a recording device using the unit.
A heat exchange member for exchanging heat with the recording head by being attached to the recording head for performing recording by heat generated by the heat generating element, and a temperature adjustment for adjusting the temperature of the recording head. The present invention relates to an apparatus, a recording head unit using the same, and a recording apparatus using the unit.

[Background Art] Recording methods for performing recording using thermal energy include, for example, a thermal recording method and a thermal transfer recording method, and ink is ejected along with growth of bubbles in the ink due to heat generated by an electrothermal transducer. There is an ink jet system or the like for performing recording. These recording methods are widely used in printers, copiers, and the like. Among them, the above-mentioned ink jet method enables high-definition and high-speed recording, and a recording head of this method is manufactured by the same process as a semiconductor device. By doing so, there are a number of advantages not found in other systems, such as a relatively low-cost configuration of the recording head and apparatus.

By the way, in a recording apparatus of the type that performs recording by using these thermal energies, generally, so-called heat storage and a temperature distribution between the recording elements due to the heat storage are generated as the recording proceeds. The occurrence of the heat storage and the temperature distribution affects the printing characteristics of the printing element, and as a result, for example, density unevenness occurs in a printed image,
In the case of color recording, problems such as loss of color balance are caused.

Such heat storage is particularly problematic in an ink jet recording apparatus of the above-described type that performs recording using ink. That is, a recording head of this type generally has a plurality of discharge ports for discharging ink, a liquid path in which an electrothermal conversion element is provided in communication with each of the plurality of discharge ports, and each of the liquid paths. Has a common liquid chamber that stores the ink supplied to the ink, and a part of the thermal energy generated by the electrothermal conversion element during recording is transmitted as heat to the liquid path and the ink in the common liquid chamber. . As a result, the temperature of the ink in the liquid path and the common liquid chamber changes, and a corresponding ink temperature distribution occurs between the respective discharge ports.

Such a change in the ink temperature affects the viscosity and the like of the ink. As a result, the amount of ink ejected from each ejection port changes, thereby changing the pixel density to be recorded. At this time, if there is a temperature distribution of the ink between the plurality of ejection ports, density unevenness occurs in an image printed according to the distribution. In color recording, the color balance is lost.

The density unevenness and the loss of the cover balance are problematic in a so-called full-line type recording head among ink jet recording heads. That is, this full-line type recording head has a plurality of ejection openings per line of recording corresponding to the width of the recording paper being conveyed. For example, when using A3 size recording paper, It has 4376 outlets and a corresponding electrothermal transducer at a density of 400 dpi.

When a large number of ejection ports are arranged in this manner, firstly, the difference in ejection frequency between the ejection ports often increases depending on the print data, which may cause a temperature distribution between the ejection ports. Secondly, for example, in the case of performing A3 size printing immediately after performing B5 size printing using a part of the ejection port array, between the ejection ports used for recording and the ejection ports that are not so far. Temperature distribution may occur.

In addition, when a plurality of print heads are used for each color ink to perform full-color printing, a temperature difference occurs between the print heads due to a difference in the frequency of use between these print heads, and a minute difference occurs in the volume of ink ejected. This may cause problems such as a loss of color balance and a difference in density depending on the ink color.

In order to alleviate the temperature distribution generated between the ejection ports of the recording head described above, or the temperature difference between a plurality of recording heads, a heat exchange member such as a heat pipe is attached to the recording head, and the heat pipe or the like is connected thereto. The present applicant has proposed a configuration for performing heat exchange with the recording head.

The heat pipe in this configuration has a working fluid such as water or Freon liquid in the hollow interior, and the working fluid is vaporized or condensed according to the relative temperature with respect to the recording head, thereby performing heat exchange (recording). Heat from the head or heating the recording head). The inside of the heat pipe is filled with the working fluid and the vaporized vapor, and the rapid heat transfer of the vapor acts on the heat pipe to always equalize its temperature.

Further, in order to promote heat exchange by the heat pipe, for example, a fin for exchanging heat (radiation) with the atmosphere in a portion where the heat pipe extends and a heat exchange structure such as a fan for blowing air to the fin are provided. The present applicant has also proposed a configuration in which heat is exchanged between the heat pipe and the heat pipe (heat pipe is heated) by a heater provided at a predetermined portion of the heat pipe.

However, the above-described heat exchange member and the recording head to which the heat exchange member is attached have room for improvement as described below regarding the heat exchange member itself and the configuration of the recording head unit using heat exchange.

[Problems to be Solved by the Invention] That is, when a plurality of recording heads are used as in a recording apparatus that performs full-color recording, the heat exchange member is also provided for each recording head.

In such a case, in order to control the temperature of each recording head via these heat exchange members, it is necessary to provide a heater as a heating element and a temperature sensor as a temperature detection element for each heat exchange member. As a result, the structure for temperature control becomes complicated and expensive.

The present invention has been made based on the above viewpoints,
Each of the heat exchange members provided corresponding to each of the plurality of recording heads is integrated by communicating with each other at a predetermined portion, and a temperature detecting element and a heating element are provided near the integrated portion of the heat exchange member. An object of the present invention is to provide a printing apparatus which can perform temperature control of a print head with a simple configuration by providing the printing apparatus.

Further, even when the integrated heat exchange member is used, a temperature adjustment device capable of performing temperature control according to the temperature of each recording head corresponding to each of the heat exchange members,
It is another object to provide a recording head unit and a recording device.

[Means for Solving the Problems] In the present invention, a heating element for generating the thermal energy is provided in a recording head unit for discharging ink using thermal energy to perform recording on a recording medium. A plurality of recording heads arranged, a plurality of heat pipe portions for the recording head provided for each of the plurality of recording heads, a heat pipe coupling portion connecting the plurality of heat pipe portions, and the heat pipe It is characterized by comprising a plurality of heating members provided on both sides of the connecting portion, and a temperature sensor provided for each of the plurality of recording heads for controlling the operation of the heating members.

Further, in a recording apparatus that performs recording on a recording medium by ejecting ink using thermal energy, a plurality of recording heads each including a heating element, a heating element for generating the thermal energy, A plurality of heat pipe portions for the print head provided for each of the plurality of print heads, a heat pipe connecting portion connecting the plurality of heat pipe portions, and a heat pipe connecting portion provided on each of both side portions of the heat pipe connecting portion. A plurality of heating members, a temperature sensor provided for each of the plurality of recording heads for controlling the operation of the heating members, and a fan provided for the heat pipe coupling portion; and a temperature for each of the heads. When any one of the sensors exceeds a first predetermined temperature, the fan is driven, and even if any one of the temperature sensors for each of the heads has the first predetermined temperature. Characterized in that to drive the heating member when: lower second predetermined temperature Ri.

Further, a temperature adjusting device for arranging a heating element for generating thermal energy and adjusting the temperature of a plurality of recording heads for discharging ink using the thermal energy to perform recording on a recording medium. A plurality of heat pipe portions for a recording head provided for each of the plurality of recording heads, a heat pipe coupling portion connecting the plurality of heat pipe portions, and a heat pipe coupling portion on each side of the heat pipe coupling portion. A plurality of heating members are provided, and a temperature sensor is provided for each of the plurality of recording heads to control the operation of the heating members.

[Operation] According to the configuration described above, the heat pipe portions provided corresponding to the plurality of recording heads are connected by the heat pipe connecting portion, and the connecting portion has a heating portion for heating this portion. Since the members are provided, the heat exchange in the heat pipe of each recording head can be controlled integrally at the connection portion.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 (A), 1 (B) and 1 (C) are views showing a copier using an ink jet recording apparatus according to an embodiment of the present invention in a recording section, and are schematic cross-sectional views as viewed from the front, respectively. FIG. 2 is a schematic cross-sectional view of only a recording unit viewed from information, and a schematic diagram of only a recording unit viewed from a side.

The copying machine according to the present embodiment is roughly divided into two parts. In these figures, reference numeral 301 denotes a scanner unit which reads a document and converts it into an electric signal. A recording unit 302 performs recording on a recording material such as recording paper based on the electric signal converted by the scanner unit 301.

In the scanner unit 301, reference numeral 401 denotes a document, and 406 denotes a document table on which the document 401 is placed, which is made of transparent glass or the like.
Reference numeral 402 denotes a document reading unit for reading an image of the document 401 by moving and scanning. Document reading unit
The 402 includes a rod array lens 403, a 1 × color separation line sensor (color image sensor) 404, and an exposure unit 405. When the original reading unit 402 moves and scans in the direction of the arrow in the drawing by a moving scanning mechanism (not shown) to read an image of the original 401 on the original platen 406, an exposure lamp constituting the exposure unit 405 of the original reading unit 402 is turned on. The reflected light from the image on the original 401 illuminated by the light is condensed by a rod array lens 403 onto an equal-size color separation line sensor (hereinafter referred to as a reading sensor) 404. The reading sensor 404 detects color image information of a document image for each of red (R), green (G), and blue (B), and converts these into electrical digital signals. This digital signal is transferred to the printer unit 302 as recording data.

In the recording unit 302, reference numeral 305 denotes a recording head unit.
As will be described later in the drawings, a so-called full line in which ejection ports are formed over the entire recording width of the recording material for each of the yellow (Y), magenta (M), cyan (C), and black (Bk) inks. 1 includes a recording head 1 of the type. Each of these recording heads is provided with a heat pipe 2 arranged on the side surface thereof for adjusting the temperature of the recording head. Note that the heed pipe of this example was integrated with the other at each end. Reference numeral 306 denotes a recovery cap section, which moves relative to the print head section 305 as necessary, as described later with reference to FIG. 14 and the like, and caps the ejection port forming surface of the print head. This prevents the ink from drying during non-printing, performs preliminary discharge, etc., and always maintains the discharge characteristics of the print head in a good condition.
During non-capping, such as during recording, the recording head unit 305 is disposed at a position facing the conveyance path of the recording sheet as shown in FIGS. 1 (A) and 1 (B).

Reference numeral 303 denotes a sheet feeding unit, which includes a cassette 411 for storing a plurality of recording sheets in a stacked state. The recording paper stored in the cassette 411 is fed to the recording paper transport path while being separated one by one by a pickup roller 412 or the like.
The fed recording paper is conveyed into a conveyance path 419 by a pair of conveyance rollers 413 and 414, and further a pair of registration rollers 4
According to 15,416, the sheet is conveyed to a position facing the ejection port surface of the recording head unit 305 while the conveyance timing is adjusted.

The recording paper transport path at a position facing the discharge port surface is formed by the belt transport unit 304. That is, the belt transport unit 3
Reference numeral 04 denotes an endless belt that adsorbs and adsorbs the recording paper and travels in the transport direction at a position facing the ejection port surface, and a drive unit for driving and driving the endless belt. The distance between the recording surface of the recording paper conveyed while being attracted to the belt and the ejection port surface of the recording head is appropriately maintained by the attraction force or the like. During this time, the four recording heads for each ink color are driven based on the recording data, and recording is performed on recording paper.

The recording sheet on which the recording has been performed is further conveyed from a position facing the recording head unit 305 by the belt conveying unit 304 and reaches the sheet discharge port. During this time, the air heated by the infrared heater 308 is sent by the fan 307 to the recording paper on the transport path. As a result, the evaporation of the water content of the ink ejected from the recording head and adhering to the sheet is promoted, and the ink fixing of the recorded image is promoted. The recording sheet that has reached the discharge port is discharged onto a discharge tray 420 by a pair of discharge rollers 213 and 214.

As described above, the heat pipe is attached to the recording head of this embodiment, so that the temperature of the recording head is adjusted to a desired temperature. As a result, the ink temperature in the print head is controlled to a favorable temperature for printing. For this reason, as shown in FIGS. 1B and 1C, a part of the heat pipe 2 extends to outside the area where the recording head is provided, and radiates excess heat there. Fins, a heater for supplying heat to the recording head, and the like are configured. A fan 4 for blowing air toward the fins is provided below the heat exchange unit.

2 (A) to 2 (C) show an example of a recording head unit having a recording head 1 constituting a recording section of the ink jet recording apparatus shown in FIG. 1 and a heat pipe 2 as a heat exchange means. 2A is a schematic perspective view showing only one of the four heads, and FIGS. 2B and 2C are a schematic plan view and a schematic side view of the entire recording head unit. .

In these figures, reference numeral 1 denotes a so-called full line type recording head provided with ejection ports corresponding to the entire width of recording on a recording material. The print head of this example has 63.5 ejection ports.
4736 pieces are arranged at a pitch of μm. An electrothermal conversion element is provided in a liquid path provided to communicate with each of these discharge ports. Utilizing the thermal energy generated by the electrothermal conversion element, the temperature of the ink in the vicinity is rapidly increased to cause film boiling, and the rapid pressure change caused by the bubble generation due to the film boiling is utilized. To eject ink.

Reference numeral 2 denotes a heat pipe provided for each of the recording heads 1 in contact with substantially the entire area except for a predetermined area in the longitudinal direction of one side surface. Each of these heat pipes 2 forms a substantially square portion 2A in a region at one end thereof which is not in contact with the recording head 1, and the end portions of the respective portions 2A are integrally formed so that the insides communicate with each other. .
By being integrally formed in this way, the structure for controlling the temperature of each heat pipe is particularly simplified. Between these parts 2A, meandering fins 3 are attached. Thereby, the heat pipe 2 and the recording head 1
A first heat exchange unit 20A that performs heat conversion between the first heat exchange unit and the second heat exchange unit 20B that extends outside and is located away from the recording area of the recording head.

The heat pipes 2 and 2A are composed of a body made of aluminum in consideration of workability, cost, as well as heat transferability, and a working fluid made of a fluorocarbon fluid injected into the hollow interior. In a heat pipe, it is generally necessary to consider the heat transport amount. In other words, there is a limit to the heat transfer amount of the heat pipe, and in order to obtain appropriate thermal characteristics for recording, the maximum heat amount transferred from the head to the heat pipe or from the heat pipe to the head at that limit It is necessary to be able to transmit the above amount of heat.

The limit amount of the heat transfer amount also has a correlation with the cross-sectional area of the heat pipe. The larger the cross-sectional area of the heat pipe, the larger the heat transfer amount.

On the other hand, when a color image is recorded by using a plurality of recording heads as in this example, generally, the larger the distance between recording heads in the recording paper transport direction, the more image data to be transferred is stored. May have to be made larger, which leads to an increase in the cost of the entire apparatus.

Further, the distance between the recording heads is small in order to improve the accuracy of the relative positioning between the recording heads and the recording paper (hereinafter, also referred to as registration) and to reduce the size of the recording apparatus. It is more preferable.

In consideration of these points, the heat pipe 2 constituting the first heat exchange unit 20A that performs heat exchange with the recording head 1 by taking into account these points has a substantially rectangular cross section, The heat pipe 2A constituting the second heat exchanging unit 20B that dissipates heat is substantially square having the same thickness as the heat pipe 2 as described above. By using a heat pipe having such a shape, the distance between the recording heads can be reduced, and efficient heat exchange can be performed without reducing the heat transport amount.

The recording head 1 and the heat pipe 2 are connected by a pressing member 8. That is, the pressure contact member 8 is a leaf spring-shaped member, and as shown in detail in FIG. 6 and the like, this portion covers almost the entire area excluding a predetermined portion in one side of the recording head 1 in the longitudinal direction. Heat pipe 2 which comes in contact with
To connect the two. Also,
As described above, the press contact member 8 is provided with several cuts in the longitudinal direction. This cut is for bringing the heat pipe 2 into pressure contact with the head 1 with a uniform pressing force, so that heat transfer between the head 1 and the heat pipe 2 is performed uniformly over the entire recording head. At the same time, smooth insertion and removal when inserting the heat pipe is also possible.

It is appropriate to use an elastic material such as SUS or phosphor bronze for this pressure contact member.
The optimum is about m to 1.0 mm. Since the thickness is very thin, even if it is in direct contact with the heat pipe 2, thermal problems such as heat conduction can be ignored.

The heat radiating fins 3 forming the heat radiating means as described above are provided at the portion of the heat pipe 2A forming the second heat exchanging section 20B.
It is mounted in a form pressed into three regions formed between the two heat pipes 2A. In order to maximize the heat radiation function of the heat radiation fins 3, the fan 4 constituting the heat radiation means is provided with a wind fan in the direction near the heat radiation fins 3 and opposed to the direction in which ink is ejected from the recording head. Is provided below the heat radiation fins 3. The maximum wind speed of the fan 4 is 3 m / sec, and only a part thereof is shown in FIG. 2 (A), and the blow port 4A extends over three regions where the fins 3 are provided.

This fan 4 is not limited to the mounting form of the present embodiment, and is a place where the problem of ink mist described below and the influence on the ink ejection direction do not occur, and the heat radiation assisting effect, the miniaturization of the device, etc. are achieved. It can be placed in the most preferred position where it can be done. 2 (B) and 2 (C), the heat pipes 2 and 2A and the recording head 1 are supported by the housing 101, but the second heat conversion section, that is, the heat pipe 2A and the fins There is no support member such as a housing at the position where 3 is disposed. Thus, there is nothing obstructing the air flow from the fan 4 and air can be satisfactorily blown to the fins 3 and the heat pipe 2A.

Although this fan 4 is provided in the main unit,
It may be provided on the recording unit side such as a recording head. The heat radiation fins 3 are provided so as to form their surfaces in a direction intersecting the longitudinal direction of the heat pipe 2 as will be described later in detail with reference to FIG. By providing the radiation fins 3 in this manner, the wind sent from below the radiation fins 3 by the fan 4 is suppressed from flowing around to the recording head side (recording area side). As a result, problems such as flying of the ink mist in the recording apparatus and changing the direction of ink ejection are reduced. The heat dissipating fins 3 are made of lightweight aluminum which is relatively excellent in heat dissipating property like the heat pipe 2.

2 (A) to 2 (C) again, reference numeral 5 denotes a temperature sensor which can be constituted by a thermistor or the like, which constitutes a second heat exchange section and is provided at the center of an area where four heat pipes 2A are integrated. Can be Reference numeral 6 denotes a heater in the form of a planar heater, which is attached to each side of the outermost heat pipe 2A among the four heat pipes 2A.

The temperature sensor used in the present example is a PCB type thermistor having a φ1.5 mm (diameter in contact with a heat pipe) × 2.5 mm (sensor thickness) in a miniature shape. As in this example, when the heat pipes 2 and 2A are so-called integral heat pipes in which a plurality of heat pipes communicate with each other at one end and share a working fluid, four heat pipes are provided by one temperature sensor 5. The temperature of the recording head 1 can be detected. In this case, the mounting position is the center of the connecting area where the heat pipes 2A are integrated as described above.

Generally, a temperature sensor is provided to detect a recording head temperature that changes with recording in the temperature control of the recording head, and it is originally mounted directly on the recording head and can detect the temperature with good responsiveness. It may be desirable.

However, the ink jet recording apparatus of the present embodiment is configured such that the recording heads can be individually exchanged as necessary, such as deterioration of the ejection characteristics of the recording head used in the apparatus. Therefore, when the temperature sensor is attached to the recording head, the work of removing the temperature sensor from the recording head at the time of replacement is troublesome, or the temperature sensor is replaced for each recording head from which the temperature sensor is removed. This also causes a problem that the cost for the temperature sensor is increased.

Further, when the temperature sensor is directly attached, the thermal conductivity is small depending on the material of the recording head, and the temperature of the portion of the recording head other than the portion where the temperature sensor is attached may not be reflected with good responsiveness. This is particularly remarkable in the case of a full-line type recording head as in this example.

For the above reasons, when the temperature sensor is installed on the heat pipe, the temperature detection that responds satisfactorily to the temperature distribution generated in the print head by the rapid temperature uniformization effect due to the good thermal conductivity of the heat pipe. It can be carried out.

In the case of this example, only one temperature sensor 5 is provided in the integrated connection area of the heat pipe 2A. This is because the heat pipe is integrated so that the temperatures of the heads are sufficiently uniform. This is effective in a printing apparatus compatible with a printing mode in which the temperature variation among the four printing heads is relatively small. However, in the detachable recording head as in this example, the thermal resistance between the recording head and the heat pipe may increase, and a temperature difference between the heads may occur. As described above, when the temperature variation between the heads becomes large, it is desirable to provide a temperature sensor corresponding to each of the four recording heads in order to perform appropriate temperature control for each recording head. In that case, the temperature sensor is preferably mounted at the center of each heat pipe 2.

On the other hand, the heater 6 is attached to the side surfaces of the two outermost heat pipes 2A as described above.

The heat pipe used together with the heater is provided to uniformly transfer the heat generated by the heater to the entire recording head by utilizing the good heat transfer property of the heat pipe. Therefore, it is desirable that the position on the heat pipe where the heater is attached is a position where at least a part of the heater corresponds to a portion corresponding to the working fluid in the heat pipe. Accordingly, the heat generated by the heater is quickly transmitted to the working fluid, and the working fluid is vaporized by this heat, whereby the gas allows rapid heat transport to the entire recording head. Incidentally, as will be described in detail in FIG. 3, in a state where the recording head and the unit of the heat pipe are mounted on the ink jet recording apparatus of this embodiment, that is, in a state at the time of recording, the heat pipe is in a state shown in FIG. 2), the recording head 1 and the heat pipe 2 extend in a horizontal direction. For this reason, at the time of recording, the hydraulic fluid is supplied to the heat pipes 2, 2A in the state shown in FIG.
Extends to the bottom of the From the above, in the present example, the planar heater 6 is attached to a portion of the heat pipe 2A corresponding to the working fluid.

When the heater is attached to any part of the heat pipe 2 corresponding to the recording head 1, the heat generated by the heater is transmitted to the recording head in the vicinity without passing through the heat pipe 2 to increase the temperature. May have adverse effects. In this sense, it is desirable that the heater 6 is provided on the heat pipe 2A remote from the recording head 1.

The heater 6 is a substantially square planar heater as described above. This is to prevent the heat generated from the heater from being concentrated on a part of the heat pipe and causing a so-called dry-out phenomenon at this part. That is, the heat generated by the heater is expanded so that the heat generated by the heater is not concentrated on a part. The heater 6
When the ambient temperature at which the apparatus of this example is used is low, the recording head temperature is raised to about 40 ° C. or higher, and the output is 100 W in order to quickly start the recording.

In this example, the heater 6 is directly bonded to the body of the heat pipe 2A. However, when a generally available heater is used, the heater is connected via a plate such as an Al plate according to the output of the heater used. The plate may be attached, or a part of the plate may be provided with holes to control the amount of heat transmitted to the heat pipe. Furthermore, when the output of the heater used is relatively large, a single heater may be provided at the connecting portion of the heat pipe 2A. At this time, the sensor 5 similarly provided in the connecting portion is mounted above (in FIG. 2C) a certain distance from the heater.

Further, the heater 6 is not limited to a planar heater, and for example, a power transistor may be used as the heater. In this case, since the power transistor is small and generates a relatively large amount of heat, the power transistor is mounted via a predetermined member in consideration of the above-described dryout phenomenon and the like.

As is clear from the above description, according to the heat pipe configuration of the present example, the number of heaters and temperature sensors can be reduced, and the cost of the mechanism for controlling the temperature adjustment of the recording head can be reduced. Become.

In FIGS. 2B and 2C, 22, 23, 24a, 24b,
Reference numeral 25 denotes a member for adjusting the registration of the recording head 1, and reference numerals 30 to 33 denote members for adjusting the warpage of the recording head. 2 (B) and 2 (C), and FIG. 11 (A)
And (B), which will be described later in detail with reference to FIGS. 12 (A) to (C).

FIG. 3A is a schematic cross-sectional view showing the internal configuration of the heat pipes 2, 2A. In the drawing, reference numeral 203 denotes a hydraulic fluid filling portion filled with a hydraulic fluid 207, and 206 denotes a partition plate provided above the hydraulic fluid filling portion 203 and covering almost the entire area of the hydraulic fluid filling portion 203 except for both ends thereof. It is. 204 is provided in a portion corresponding to the heat pipe 2, and is a hydraulic fluid vapor passage formed above the partition plate 206, and 205 is provided in a portion corresponding to the heat pipe 2 A and formed as a heat radiator formed above the partition plate 206. Section (condensing section).

The heat pipes 2 and 2A as described above are used, and are connected to the recording head 1 as described in detail in FIG. When a recording head is operated with such a recording head 1, the heat generated from the electrothermal transducers provided corresponding to the respective ink discharge ports first flows into the working fluid filling section 203 (in the figure, arrow D). direction). This heat is generated by the hydraulic fluid 207
With the convection and evaporation of the fluid, it is quickly diffused to almost the entire area of the working fluid filling section 203, and the inside of the working fluid filling section 203 is made uniform. By equalizing the temperature of the filling portion 203, the ink temperature in the vicinity of the recording head 1 where the electrothermal transducer is provided, that is, the recording head temperature is also equalized.

Further, the steam generated in the hydraulic fluid filling section 203 is
It reaches the steam passage 4 through a portion of the end portion without the partition plate 206 and passes through the steam passage 4 (in the direction of arrow E in the figure).
And moves in the direction of arrow F in the figure. During this transfer, the steam is condensed with heat. This condensed hydraulic fluid 207
Moves along the inner wall of the pipe body constituting the heat pipe 2A and moves in the direction of arrow G in FIG.
Return to 3.

In the operation of the hydraulic fluid described above, the provision of the partition plate 206 makes it possible to perform the temperature equalizing action of the recording head by the hydraulic fluid independently of the condensing action of the hydraulic fluid. That is, heat generated in the recording head 1 with a temperature distribution that varies between the ejection ports, the heat pipe 2A
As described above, the heat generated from the heater 6 attached to the side surface of the recording head 1 is quickly equalized in the working fluid filling unit 203, and as a result, the temperature between the ejection ports of the recording head 1 is made uniform. At this time, the behavior of heat in the heat radiating portion 205 is
Does not reach the working fluid filling section 203. Thereby, an efficient temperature equalizing action and a heat radiating action by the heat pipe become possible. In addition, due to the presence of the partition plate 206, it is possible to satisfactorily circulate the heat until the excess heat in the hydraulic fluid filling unit 203 reaches the condensation in the heat radiation unit 205.

Further, the partition plate prevents the working fluid from being wiped off with the movement of the steam, thereby preventing the temperature rise of the recording head due to the dryout phenomenon.

In order to smoothly perform a series of operations using the above-described hydraulic fluid, it is desirable to arrange the heat radiating unit 205, the steam passage 204, and the hydraulic fluid filling unit 203 in order along the direction of gravity.

According to the configuration of the heat pipes 2 and 2A as described above, the third
As compared with the conventional heat pipe as shown in FIG. 3C, the recording head can be more efficiently temperature-equalized and radiated more efficiently, and a simple heat pipe can be obtained. That is, FIG. 3 (C) shows a cross section of a conventional heat pipe. In this heat pipe, the hydraulic fluid condensed and adhered to the inner wall of the heat pipe is moved by capillary force to a portion corresponding to a recording head of the heat pipe. A groove for movement is provided. Therefore, it is necessary to provide a groove on the inner wall of the heat pipe, which may increase the cost. Further, according to this conventional heat pipe, it is not possible to perform efficient temperature equalization or the like because there is no partition plate.

Note that the function of the partition plate 206 according to the present embodiment is not only to perform the temperature equalizing action independently and efficiently as described above, but also to perform capping as described later in FIG. 13, for example. When the recording head 1 moves, the partition plate 206 prevents uneven distribution of the hydraulic fluid in the heat pipes 2 and 2A due to this movement. This allows
Even during the capping operation, temperature uniformization and heat radiation can be performed well. When the recording head to be used is a so-called serial type recording head for performing recording along with the scanning movement, the function of the partition plate is particularly remarkably exhibited.

FIG. 3B shows an embodiment in which the ink ejection direction is a direction (horizontal direction) perpendicular to the direction of gravity. In this case, the heat radiating unit 205, the vapor passage 204, the working fluid filling unit 203, and the heat generating unit of the recording head 1 are arranged in this order along the direction of gravity.
It is possible to exhibit the same temperature equalizing action and heat radiating action as in the embodiment shown in FIG. 3 (A). In this configuration, it is desirable to dispose the heat-generating portions existing in the vicinity of the discharge port surface and its vicinity in the horizontal direction as shown in FIG. 3B in order to maintain the recording characteristics. This will be described in detail with reference to FIG.

FIG. 4 is a schematic cross-sectional view showing details of the fin 3 shown in FIG. 2 and the like, and is a cross-section viewed from a direction indicated by an arrow B in FIG. 2 (B). FIG. 4 shows only a part of the fin 3.

As is apparent from FIG. 4, the fin 3 is provided with a plurality of slit plates 3A which are alternately opened in the lower right or lower left direction in the figure for each predetermined region and the slits 3B formed therewith. With this fin configuration, the flow of air blown by the fan 4 from below in the figure as shown by the arrow, when flowing into the fin 3, a part of the air flows in the opening direction by the slit plate 3A as shown by the arrow in the figure. Receives a corresponding deflection. Thereby, the airflow flowing between each of the plurality of fins 3 is in a turbulent state. In this turbulent state, the heat of the fins 3 is transmitted relatively well to the air flow, and the air flow from the fins 3 is hardly separated, so that the efficiency of heat radiation from the fan 3 is improved.

Furthermore, by providing the slit plate 3A, the fin 3
The overall surface area for heat dissipation increases, which also improves heat dissipation efficiency.

The fins 3 of this example are arranged in three spaces formed by four heat pipes 2A, and form a meandering shape in each space. According to the above configuration, the heat pie
Combined with the plate shape of 2A, the space for disposing the second heat exchange section is reduced, and at the same time, the heat dissipation effect is not impaired by the meandering shape and the configuration of the slit plate.

In addition, about the shape of the heat pipe and the fin,
The present invention is not limited to this example, and may be, for example, one as shown in FIG. 16 according to the required amount of heat radiation or the amount of air blown from the fan. Also in this case, by providing the slit and the slit plate in the fin 3, the heat radiation efficiency is improved.

In addition, the opening direction of the slit plate and the number of each area are not limited to the above example, and, for example, for example,
The opening directions of the slit plates may be alternately changed one by one.

FIG. 5 is a block diagram showing a control configuration of the recording unit 302 using the ink jet recording apparatus of this example. In this figure, illustration of each control configuration such as a recording paper transport system is omitted,
A control configuration for adjusting the temperature of the recording head 1 is mainly shown.

In FIG. 5, reference numeral 100 denotes a CPU, which executes control processing such as operation, data processing, and the like in the recording unit 302 using the inkjet recording apparatus of the present embodiment. 100A is RAM used as a work area in control processing by CPU 100, 100B
Is a ROM for storing a processing procedure relating to the recording section 302 such as a processing procedure described later in FIG. 1A is a head driver for driving the electrothermal transducer of the recording head 1 based on a drive data signal and a control signal transferred from the CPU 100, and 4A and 6A are fans 4 based on a control signal from the CPU 100, respectively. Fan motor 4B for rotating the
And a fan motor driver and a heater driver for driving the heater 6.

The CPU 100 performs predetermined processing on the print data transferred from the scanner unit 301, and transfers the print data as drive data to the head driver 1A in synchronization with the conveyance of the print sheet. At the same time, based on the temperature of the recording head 1 detected by the temperature sensor 5, the CPU 100 controls the temperature of the recording head as described later with reference to FIG.

6A and 6B are side views of the recording head 1 and the heat pipes 2, 2A, showing the details of the recording head 1 and the manner of mounting the heat pipes 2, 2A.

In these figures, reference numeral 10 denotes an electrothermal conversion element for generating thermal energy used for discharging ink, and 4376 pieces are arranged at a density of 400 dpi in the vertical direction in FIG. A discharge port (not shown) is also provided. Reference numeral 11 denotes a substrate on which the electrothermal conversion elements 10 are provided.
10 is a top plate that forms a liquid path that communicates with the discharge port and has a common liquid chamber for supplying ink to the liquid path. Reference numeral 13 denotes a base which supports the substrate 11 and forms a main body of the recording head.

In the configuration described above, as shown in FIG. 6 (B), the heat pipe 2 is a side surface region of the base 13 supporting the substrate 11 on which the electrothermal conversion element is provided, and the heat pipe 2 is provided with the electrothermal conversion element. It is attached to an area outside the area corresponding to the set part. That is, the heat pipe is not attached to the area where the electrothermal conversion element is provided with the substrate 11 and the base 13 interposed in the thickness direction.

When the heat pipe is provided in a region corresponding to the electrothermal conversion element, the ink temperature and ink ejection near the electrothermal conversion element are easily affected. That is, for example, when a heat pipe is not provided in the vicinity, about 40 to 60% of the heat generated by the electrothermal transducer is used as energy for ejecting ink, whereas the heat pipe is electrically heated. When provided near the converter, the amount of heat transfer between the heat pipe and the vicinity increases, and only a part of the heat energy generated by the electrothermal conversion element, for example, about 10%, is involved in ink ejection. become unable. If it is attempted to perform good ink ejection under such conditions, the thermal energy generated by the electrothermal transducer increases, so that, for example, it is necessary to increase the voltage or pulse width of the driving pulse, resulting in power consumption. Increase. Further, when the generated thermal energy increases, it is necessary to increase the speed of heat transport for equalizing the recording head temperature, which complicates the configuration.

In addition, since the amount of heat transfer between the heat pipe and the vicinity of the electrothermal conversion element increases, the heat of the heat pipe easily moves to the vicinity of the heat pipe, and the ink temperature in this portion becomes unnecessarily high. In some cases, a desired amount or more of ink is ejected to affect the density of an image to be printed.

As described above, by providing the heat pipe in contact with the area of the recording head outside the area where the electrothermal transducer is provided, excessive heat transfer from the vicinity of the electrothermal transducer and to the vicinity thereof occurs. Therefore, the ink discharge characteristics and temperature control of the recording head using the heat pipe can be favorably performed.

In addition, according to the arrangement of the heat pipes as described above, the ink temperature mainly in the ink liquid path and the common liquid chamber is more easily controlled than in the vicinity of the electrothermal transducer of the recording head. This makes it possible to stabilize the ink viscosity especially in the entire full-line type recording head,
It is possible to stabilize the responsiveness of the ink behavior, such as the infill refill.

FIGS. 7A and 7B are a schematic front view and a schematic side view showing a second embodiment having the configuration shown in FIGS. 6A and 6B.

7 (A) and 7 (B), reference numeral 1 denotes an ink jet recording head according to the present embodiment, 11 denotes a substrate of the recording head 1, 2 denotes a heat pipe disposed along the substrate 11, and Electrothermal conversion element 10, liquid path 14, and discharge port
15 is formed. Reference numeral 16 denotes a top plate for forming the liquid path 14 and the discharge port 15.

Now, for the recording head 1 described above, 1 mm
When a silicon plate having a thickness is used, 33
(V), when a drive pulse having a pulse width of 7 (μs) is applied, heat generated by the element 10 is transmitted through the substrate 11 as shown in FIG.
As shown by the middle arrow, the light diffuses slowly and is transmitted to the heat pipe 2. At this time, the temperature of the recording head 1 is constantly maintained at 45 to 52 by blowing air of 2 m / s by a heater and a fan having an output of 50 W.
It could be maintained stably in the range of ° C. In contrast, when a silicon substrate having a thickness of 0.4 mm was used as the substrate 11, a similar drive pulse was applied, but ink could not be ejected.

The above experimental results can be explained as follows. That is, as the thickness of the silicon substrate becomes smaller,
The heat easily flows into the heat pipe 2 through the heat pipe 11, and thus the amount of heat flowing therethrough increases.
The amount of heat transmitted to the ink that is in contact with the inner electrothermal conversion element 10 is reduced. Therefore, a silicon substrate of 0.5 mm or less
When used as 1, heat energy required for ink foaming cannot be obtained from the electrothermal converter 10, and stable ejection cannot be performed. When the calorific value ratio transmitted to the heat pipe 2 was actually measured in each of the above experiments, when the thickness of the silicon substrate was 1 mm, the electrothermal conversion element 1
When the power input to 0 is about 70% and the thickness of the silicon substrate is 0.5 mm, about 80% of the power input is converted to heat pipe 2
It can be seen from the above experimental results that the amount of heat diffused and transmitted to the heat pipe 2 is desirably kept to about 70%.

FIGS. 8A and 8B show a recording head and a heat pipe according to the third embodiment. The recording head 1 of this embodiment has a second substrate 11B made of aluminum or copper having good heat conductivity between a first substrate 11A such as a silicon substrate on which the electrothermal transducer 10 and the like are provided and a heat pipe 12. FIG. 8B shows the heat flux from the recording head 1 side.
The diffusion as shown by the middle arrow prevents the concentration, and therefore, prevents the heat transport capability of the heat pipe 2 from becoming excessive.

As an experiment using the third embodiment, the first substrate 11A was the same as that of the first embodiment, the second substrate 11B was an aluminum substrate having a thickness of 5 mm, a low voltage of 30 (V) and a pulse width of 7 μs. By supplying the energy drive pulse to the electrothermal transducer 10, good ink ejection characteristics could be obtained.
In this experiment, the heat pipe 2 having a maximum heat transport capacity of 70 (W) was used, and the recording head 1 could be constantly controlled at 45 ° C to 52 ° C. However, if the thickness of the second substrate 11B is 10 mm or more, the heat transfer becomes too low, and
The range of 45 ° C to 52 ° C cannot be controlled.

9 (A) and 9 (B) are views for explaining the configuration of attaching and detaching the recording head, and FIG. 9 (A) shows a state in which four recording heads 1 are mounted as viewed from the side. Sectional view, ninth
FIG. 2B is a perspective view showing a state where the recording head is detached.

In FIG. 9 (A), the heat pipes 2 and 2A are formed by housing (not shown) near the boundary between the heat pipe 2 and the heat pipe 2A, that is, near the boundary between the first heat exchange section and the second heat exchange section. The recording head 1 having a pressing member 8 is fixed to the heat pipe 2 from above in FIG. Before the recording head 1 is mounted, as shown in FIG. 6A, the pressing member 8 is slightly inclined toward the recording head 1. When the recording head is mounted, the heat pipe 2 is inserted into a space between the pressing member 8 and the recording head 1, and the heat pipe 2 is relatively pressed toward the recording head 1 by the elastic force of the pressing member generated at this time.

FIG. 9B shows a state before the recording head 1 is inserted into or detached from the housing 101. in this way,
Since the recording head 1 can be individually attached and detached for each ink color, the recording head can be easily replaced.

FIG. 10 shows a configuration in which the recording head is fixed to the housing 101 and four heat pipes 2 and 2A are integrally attached to and detached from the housing 101, contrary to the configuration shown in FIG. In this configuration, as shown in the figure, the insertion direction of the heat pipes 2 and 2A is the longitudinal direction of the recording head, and the heat pipes 2 are inserted between the pressing member 8 and the recording head 1, respectively.

As described above, when the recording head 1 and the heat pipe 2 are fixed to each other by the pressing member 8 in the attachment and detachment of the recording head shown in FIG. 9 and FIG.
The positioning in the recording paper conveyance direction, that is, the direction perpendicular to the longitudinal direction of the recording head 1 is favorably performed.

Next, a description will be given, with reference to FIGS. 2B and 2C, of the positioning mechanism of the recording head and the registration mechanism between the heads and the operation thereof in the ink jet recording apparatus configured as described above.

In these figures, reference numeral 101 denotes a housing for holding a plurality of print heads 1 and a heat pipe 2 attached along the side surfaces of these print heads 1, and 101 A and 101 B denote a discharge surface 1 A side of each print head 1. Are positioning surfaces in which the positioning in the direction of arrow C is performed by abutting both end portions. Further, one of these positioning surfaces, that is, the positioning surface 101B on the side where the heat pipe 2 is restrained by the housing wall 101C has a head positioning pin 25 projecting therefrom, and is provided on the recording head 1. The position of this end of the head 1 is regulated by fitting the pin 25 into the elongated hole 1B extending in the direction of the arrow A.

Reference numeral 22 denotes an upright spring that stands on the housing 101 and abuts against the side surface of the other end of the recording head 1 to regulate the position of the head 1 in the direction of arrow B. This is a pressing spring that comes into contact with the other end face of the recording head 1 and regulates the position of the head 1 in the direction of arrow A. 24A and 24B are both rotatable eccentric top members erected on the positioning surface 101A, and have eccentric cams 26A and 26B for keeping contact with the head 1, and the eccentric cam members 26A and 26B are operated by rotating the eccentric top member 24A. This end of the recording head 1 can be slightly moved in the direction of the arrow B through 26A. Further, by rotating the eccentric frame member 24B, the other end of the recording head 1 can be slightly moved in the direction of arrow A via the cam 26B.

Therefore, in the recording head position adjusting mechanism configured as described above, each recording head 1 is fitted to the corresponding heat pipe 2 from above the housing 101 in a state where the heat pipes 2 and 2A are mounted on the housing 101. The heat pipe 2 is clamped between the recording head 1 and a pressing member 8 formed by a leaf spring attached to each recording head 1. At the same time, the head fixing pin 25 provided on the housing positioning surface 101B is fitted into the long hole 1B of the head 1, and the recording head 1
The head 1 is positioned in the direction of arrow C by bringing both ends of the discharge surface 1A into contact with the positioning surfaces 101A and 101B of the housing.

In this state, one end of the recording head 1 in the longitudinal direction is in contact with the pressing spring 23, and the other end is kept in a state regulated by the pressing spring 22 and the eccentric top members 24A and 24B. . Therefore, the position of each recording head 1 in the direction of arrow A is adjusted by rotating the eccentric frame member 24A, and the recording head 1 is rotated about the head fixing pin 25 by rotating the eccentric frame member 24B. Can be finely adjusted with respect to the direction of arrow B on the side that keeps contact with the eccentric cam 26B. Thus, for example, a shift between images recorded with inks of different colors can be corrected, and higher-quality image recording can be obtained.

Next, with reference to FIGS. 2B and 2C again, a description will be given of the means for adjusting the warpage of each recording head 1. FIG.

In these figures, reference numeral 30 denotes a fixed block which is attached so as to extend over substantially the center of the upper surface of the housing wall 101C, and 31 denotes a slide block fitted into the fixed block 30. The slide block 31 is a side surface of each recording head 1. The recording head 1 is positioned above the slide block support hole 30A provided in the fixed block 30 as shown in FIGS. 11 (A) and 11 (B). Can be moved in a direction perpendicular to.
Reference numeral 32 denotes a warp adjusting screw member screwed to the slide block 31, and reference numeral 32A denotes a tapered portion formed at the tip of the screw member 32. On the other hand, each recording head 1 has a slide block 31 substantially at the center in the longitudinal direction and a screw member.
A warp adjusting section 33 is provided at a position corresponding to 32, and the taper section 32 </ b> A of the screw member 32 is introduced into a hole 34 of the adjusting section 33. 34A and 34B are tapered surfaces formed in the hole 34, respectively.

By the way, in the inkjet recording apparatus having the full-line recording head 1 as described above,
The longer the recording head 1 is, the more easily the recording medium is warped in the transport direction. Therefore, if recording is performed with such a warp, the recorded image will be displayed as shown in FIGS.
, A distortion having a tendency as shown by a broken line occurs. According to the warp adjusting means of this embodiment, such a warp of the recording head can be easily adjusted so that a normal recorded image as shown in FIG. 12B can be obtained. Now, for example, when it is desired to adjust the warpage in the direction of arrow L in one recording head 1 as shown in FIG. 11 (A), the slide block 31 is positioned at the position shown in FIG. 32A warp adjustment block 33 taper surface 34A
By performing a screwing operation of the screw member 32 so as to press the central portion of the recording head 1 with the heat pipe 2, the central portion of the recording head 1 can be extruded in the pressure direction. When it is desired to adjust the warp in the right direction indicated by the opposite arrow R, the taper portion 32A of the screw member 32 is pressed against the taper surface 34B of the warp adjustment portion 33 as shown in FIG. Screw member 3
It is sufficient to perform the screwing operation of 2. The warpage adjusting means is used not only for completely eliminating the warpage as shown in FIG. 12 (B), but also for adjusting such that a plurality of recording heads have the same warpage. Can also.

In the above-described embodiment, the position adjustment and the warpage adjustment of the recording head in the case where the plurality of heat pipes 2 are communicated with each other at the end 2A have been described. The present invention is not limited to the case where the heat pipe and the recording head are provided in various forms. For example, as shown in FIGS. 16 (A) and 16 (B), each heat pipe 2 is individually held in the housing 101. In addition, it is needless to say that the present invention can be applied to a configuration in which the recording head 1 is attached to each of the heat pipes 2. The present invention can be widely applied to a form in which the pipe is joined.

Further, by using the above-described warpage adjusting means in combination with the above-described position adjusting mechanism, registration can be perfectly performed, and furthermore, distortion of a recorded image due to warpage of the head and color misregistration particularly in the case of color can be eliminated. An inkjet recording apparatus can be provided.

Further, although not shown, for example, the eccentric top member 24A
Alternatively, the eccentric top member 24B has a double screw structure, and the end portion of the recording head 1 is finely moved in the vertical direction via the cam 26A or 26B by this screw mechanism to reduce the distance between the recording material and the recording head 1. It is also possible to configure to adjust.

You.

FIGS. 13 (A) to 13 (E) are diagrams for explaining a moving mechanism of a unit composed of a recording head and a heat pipe. FIG. 13 (A) shows a recording head unit 305 and a recovery system unit 306. FIG. 13B is a schematic top view showing these drive systems, FIG. 13B is a schematic top view showing the recovery system unit 306, and FIGS. 13C to 13D are print head units 305 and recovery systems, respectively. FIG. 8 is a schematic sectional view for explaining mutual movement with a system unit 306.

As described above, the print head unit 305 and the recovery system unit 306 of this example move together from the position at the time of printing in order to perform capping for always maintaining good ink discharge and discharge recovery processing in this capping state. And take the appropriate arrangement.

In FIGS. 13 (A) and (B), reference numeral 26 denotes a recovery system unit drive unit, which is driven by belt pulleys 2001 and 200.
2 and transmitted to the recording head unit drive unit 2004 via the timing belt 2003. Head unit drive unit 20
04 has a torsion angle of 45 to convert the drive direction to a right angle direction.
The helical gear pair 2005, the spur gears 2006 and 2007, and the worm reducer 2008 are arranged, and the driving force input by the belt is finally transmitted to the rack gear 2009 via the spur gear train. The driving force of the rack gear 2009 is transmitted to racks 2010 provided at two longer positions of the housing 101 having a rectangular frame shape, and converted into vertical movement of the housing 101. The housing 101 is provided with rollers 2011 and 2012 at the front and rear, and each moves along the inner surface of the head unit moving rails 2013 and 2014, so that the housing 101 moves up and down, that is, the recording head and the heat The pipe is moved in the vertical direction.
Thus, the housing 101 can be moved only by the driving force from the driving source side due to the characteristics of the worm speed reducer, and the recording head itself falls naturally even when a plurality of heads mounted in the housing 101 overlap. There is no serious accident, and the position of the head unit can be fixed at the position where the driving of the motor is stopped.

The heat pipes 2 and 2A are connected to the rack gear 200 of the housing 101.
9, supported by the shorter frame near where Roller 2012 is located. Therefore, in this example, the center of gravity of the unit including the recording head 1 and the heat pipes 2 and 2A is set to be present in the region near the portion where the heat pipes 2 and 2A are supported. Thus, when the head unit 305 moves for capping or the like, vibration of the recording head 1 and the heat pipes 2 and 2A caused by acceleration and deceleration of the movement can be reduced. By reducing the vibration, unnecessary flow of the working fluid in the heat pipe can be prevented, and the temperature of the recording head using the heat pipe can be controlled continuously even during the capping operation.

13 (C) to 13 (E) are cross-sectional views of main parts of the head unit moving mechanism. There are three stop positions of the head unit: a head recovery position (capping position), a recording position, and an escape position. FIG. 13 (C) shows a recovery position (capping position), FIG. 13 (D) shows a recording position, and FIG. 13 (E) shows a retreat position. Each of these position detections is accurately performed by shielding the detectors of the sensors 51a to 51c arranged corresponding to each stop position with the light shielding plate 2021 provided on the housing 101.

Next, a driving mechanism of the recovery unit 306 of the recording head will be described. As shown in FIGS. 13 (A) and (B),
26 is a recovery system unit drive unit, and this drive force is transmitted to the drive wire pulley 2015. Drive wire pulley 2015
Is wound with a driving wire 2016, and both ends of the wire are respectively attached to a wire bridging member 2019 attached to the recovery system container 306A via tension pulleys 2017 and 2018. The recovery container 306A is slidable on the slide shaft 2020 via a slide bearing (not shown) on the rear side, and a slide roller 2030 slides on the rail 2031 on the front side. As a result, the drive by the drive unit is converted into reciprocating motion of the recovery system container 306A, and the recovery system container 306A is driven.
306A is moved from the recovery position, that is, the capping position to the retreat position.

The stop positions of the recovery container 306A are the position shown in FIG. 13 (B), that is, the recovery position and the position shown in FIG. 13 (A), that is, the retracted position.
A light-shielding plate (not shown) attached to the light-shielding plate accurately shields light from a detection unit of a sensor such as a photo-interrupter arranged corresponding to each stop position.

FIG. 14 (A) is a flowchart showing a processing procedure of printhead temperature control by the control configuration of the present embodiment shown in FIG. 2, FIG. 5, and the like.

In this process, every time a predetermined amount of printing operation is performed in step S101, for example, a printing operation for one row by each print head 1, whether or not the sensor 5 is at or above a predetermined temperature (for example, 50 ° C.) is determined in step S103. Is determined. If the determination is affirmative, the fan 4 is driven in step S105, and the driving of the heater 6 (if driven) is stopped. After this processing and in the case of a negative determination in step S103, step S107
Then, it is determined whether the temperature T is equal to or lower than a predetermined temperature T ₂ (for example, 45 ° C.). Here, in the case of an affirmative determination, step S1
At 09, the heater 6 is driven, and the driving of the fan 4 (if driven) is stopped. Thereafter, it is determined in step S111 whether or not the recording operation has been completed. If the determination is affirmative, the present process ends. If the determination is negative, the process returns to step S101 to perform the predetermined amount of recording operation.

The above-described processing of the present example is a processing in a case where one temperature sensor 5 is provided at a connecting portion of the heat pipe 2A where the four heat pipes 2 are integrated as shown in FIG. 2 and the like. is there. As described above, when a remarkable temperature difference occurs between the four print heads, a temperature sensor is provided for each print head. FIG. 14 (B) shows a processing procedure of the temperature control in this case.

After the recording operation in step S201, in steps S203 to S209, the temperatures T _Bk , T _Y , T _M , and T _C detected by the temperature sensors provided for the respective recording heads are respectively higher than the predetermined temperature T ₁ . Is also high. These decision step if there is a predetermined temperature above T ₁ of the recording head even one
Turn on the fan with S211. Next, in step S213～S219, the detected temperature _{T Bk, T Y, T M} , T C is determined whether the lower than the predetermined temperature T _2.

If at least one of these determinations is affirmative, step S2
Proceed to 21 to determine whether the fan is off. Only when the fan driving is off, the driving of the heater is turned on in step S223. This prevents the fan and heater from being driven simultaneously. That is, by prioritizing the driving of the fan, unnecessary heating of the recording head due to driving of the heater is prevented.

Four temperature of the recording head when it is determined that all the predetermined temperature T ₂ below, to turn off the driving of the fan at step S225.

When an image having a high duty portion is printed by the control procedure shown in FIG. 14 (B), for example, Bk = 10% and C = 80 for each ink as the printing duty.
FIG. 15A shows a change in temperature of the recording head when an image of%, M = 70%, and Y = 20% is recorded. As can be seen from this figure, the temperature of the print head (Y, Bk) having a low print duty drops sharply. As the temperature decreases, the density change of the image density also increases.

On the other hand, in addition to the control shown in FIG. 14 (B), the drive signal waveform of each recording head is changed to a voltage value pulse width T _{C, M, Bk} <40 ° C. 35 (V) 7 (μs) T _{C , M, Bk} <45 ° C. 33 (V) {TC _{, M, Bk} ≧ 45 ° C. 31 (V)} The voltage of the drive pulse is changed according to each head temperature. According to this, the image density can be made uniform as shown in FIG. 15 (B).

In the above case, the voltage of the drive pulse is changed, but the same effect can be obtained by changing the pulse width of the drive pulse. For example, voltage value pulse width T _{C, M, Bk} <40 ° C. 31 (V) 9 (μs) T _{C, M, Bk} <45 ° C.８8 (μs) T _{C, M, Bk} ≧ 45 ° C. ↑ 7 (μs The same effect can be obtained by setting.

Further, by using a two-divided pulse as the driving pulse, the image can be further stabilized.

For example, voltage value pulse width T _{C, M, Bk} ≦ 35 ° C. 31 (V) 2 divisions, 4+ (pause 3) +5 (μs) T _{C, M, Bk} <40 ° C. な し No division 9 (μs) T _{C, M, Bk} <45 ° C. な し No division 8 (μs) T _{C, M, Bk} ≧ 45 ° C. No division 7 (μs), a greater effect can be obtained.

Furthermore, since the heat pipe used in this example has a relatively large heat melting capacity, it takes a very long time to warm up until the recording head temperature reaches a temperature at which recording can be started after the apparatus is turned on. There are many. Therefore, the fourteenth
If the processing shown in FIG. 4C is performed at the time of warm-up, the warm-up time can be significantly reduced (for example, 2 minutes to 40 minutes).
Seconds) can be achieved.

That is, the drive voltage for preheating is set according to the head temperature determination performed stepwise in steps S305 and S309. For example, when the head temperature is relatively low, preheating is performed with a large voltage.

FIGS. 16A and 16B are schematic top views and side views showing another embodiment of the recording head unit including the recording head 1, the heat pipe 2, and the housing 101 for supporting these. It is an outline sectional view.

The configuration of the present embodiment is different from the above-described embodiment in that the four heat pipes 2 are not integrated at their ends but are independent, and the fins 3 are also provided independently in accordance therewith. However, only the mounting positions and the numbers of the temperature sensors and heaters are different from those in the above example, and there is no difference in the configurations and effects described in the respective parts regarding the above example except for this.

Although the above embodiment has been described with respect to the ink jet recording apparatus, the application of the present invention is not limited to this method, and the present invention can be applied to a recording apparatus of a heat sensitive type or a thermal transfer type.

(Others) In addition, the present invention brings about an excellent effect in a bubble jet type recording head and a recording apparatus as described above. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

As for the representative configuration and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or the liquid path holding the liquid (ink). Applying at least one drive signal corresponding to recording information and providing a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, thereby causing the electrothermal transducer to generate heat energy, and This is effective because film boiling occurs on the heat energy acting surface of the liquid, and as a result, bubbles in the liquid (ink) corresponding to this drive signal one-to-one can be formed. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in U.S. Pat. Nos. 4,463,359 and 4,434,262 are suitable. Further, when the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As a configuration of the recording head, in addition to a combination configuration (a linear liquid flow path or a right-angled liquid flow path) of a discharge port, a liquid path, and an electrothermal converter as disclosed in the above-mentioned specifications, A configuration using U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which is disposed in a bending region, is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be particularly effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by the recording apparatus as shown in the above embodiment. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, the present invention is also applicable to a serial type. As such a recording head, a recording head fixed to the apparatus main body, or an electric connection with the apparatus main body by being attached to the apparatus main body. The present invention is also applicable to a case where a replaceable chip-type recording head that enables connection and supply of ink from the apparatus main body, or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used. It is valid.

Further, it is preferable to add recovery means for the print head, preliminary auxiliary means, and the like provided as a configuration of the printing apparatus in the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, capping means for the recording head, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof, Performing a preliminary ejection mode in which ejection is performed separately from printing is also effective for performing stable printing.

Regarding the type or number of print heads to be mounted, for example, in addition to the one provided corresponding to a single color ink, a plurality provided corresponding to a plurality of inks having different print colors and densities. May be used. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also extremely effective for an apparatus provided with at least one of full colors by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink that solidifies at or below room temperature and softens or liquefies at room temperature, or the ink itself in an inkjet method. In general, the temperature is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. I just need. In addition, the temperature rise due to thermal energy can be positively prevented by using it as energy for changing the state of the ink from a solid state to a liquid state, or ink that solidifies in a standing state to prevent evaporation of the ink can be used. In any case, the ink is liquefied by the application of the thermal energy according to the recording signal, and the ink is liquefied, and the liquid ink is discharged. The present invention is also applicable to a case where an ink that liquefies for the first time by energy is used. The ink in such a case is disclosed in
No. -56847 or JP-A-60-71260, while being held as a liquid or solid substance in a porous sheet recess or through hole, facing the electrothermal converter. It is good also as a form. In the present invention,
The most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition to the above, the form of the ink jet recording apparatus of the present invention is not only used as an image output terminal of an information processing device such as a computer, but also takes a form of a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. And so on.

[Effects of the Invention] As is clear from the above description, according to the present invention, the heat pipe portions provided corresponding to the plurality of recording heads are connected by the heat pipe connection portion, and furthermore, the connection portion is connected to the connection portion. Is provided with a heating member for heating this portion, so that heat exchange in the heat pipe of each recording head can be controlled integrally at the connection portion.

As a result, the temperature of the recording head can be made uniform with a simple control configuration, and as a result, the variation in image density can be reduced.

[Brief description of the drawings]

1 (A), 1 (B) and 1 (C) are a schematic front sectional view, an upper sectional view and a side sectional view, respectively, of a copying machine using an ink jet recording apparatus according to an embodiment of the present invention in a recording section. 2 (A), (B) and (C) are a perspective view, a top view and a side sectional view, respectively, of a recording head unit comprising a recording head and a heat pipe according to an embodiment of the present invention, and FIG. 3 (A). 3 (B) is a schematic cross-sectional view showing the internal configuration of a heat pipe according to one embodiment of the present invention, FIG. 3 (C) is a cross-sectional view of a conventional heat pipe, and FIG. FIG. 5 is a schematic cross-sectional view showing a detailed shape of a fin according to an example, FIG. 5 is a block diagram showing a control configuration of an ink jet recording apparatus according to an embodiment of the present invention, and FIGS. 6 (A) and (B) show the present invention. To the heat pipe record for one embodiment 7 (A) and (B) are front and side sectional views showing another embodiment of the heat pipe mounting mode shown in FIG. 6, and FIG. 8 ( A) and (B) are front and side sectional views showing still another embodiment of the heat pipe mounting mode shown in FIG. 6, and FIGS. 9 (A) and (B) show one embodiment of the present invention. FIG. 10 is a cross-sectional view and a perspective view showing the attachment / detachment mode of the recording head and the heat pipe, respectively. FIG. 12A and 12B are cross-sectional views showing a recording head warpage adjusting mechanism according to an embodiment of the present invention. FIGS. 12A to 12C are FIGS. 11A and 11B. Recording for explaining the warpage of the recording head with respect to the indicated warpage adjusting mechanism FIGS. 13A and 13B are top sectional views of a copying machine showing a moving mechanism of a recording head unit and a recovery system unit according to an embodiment of the present invention, and FIGS. (E) is a sectional side view showing the moving position of the recording head unit and the recovery system unit by the moving mechanism shown in FIGS. 13 (A) and (B), and FIGS. 14 (A) to (C) show the present invention, respectively. 15A and 15B are flowcharts showing the processing procedure of printhead temperature control according to one embodiment. FIGS. 15A and 15B show the printhead temperature and the temperature of the printhead by the temperature control shown in FIGS. 14A to 14C, respectively. 16A and 16B are a top view and a side sectional view showing another embodiment of the unit including the recording head and the heat pipe shown in FIG. 2; FIG. It is. 1 ... recording head, 2,2A ... heat pipe, 3 ... fin, 3A ... slit plate, 3B ... slit, 4 ... fan, 5 ... temperature sensor, 6 ... heater, 8 ... pressing Member, 10 electrothermal transducer, 11 substrate, 11A first substrate, 11B second substrate, 12 top plate, 22 pressing spring, 24a, 24b eccentric top, 25… fixed pin, 30… fixed block, 31… slide block, 32… warp adjustment screw, 33… warp adjustment section, 100… CPU, 100A… RAM, 100B… ROM, 101… ... Housing, 301 ... Scanner unit, 302 ... Recording unit.

Continuation of the front page (56) References JP-A-55-130781 (JP, A) JP-A-55-117672 (JP, A) JP-A-58-107565 (JP, A) JP-A-1-207505 (JP) , A) Japanese Utility Model Application Sho 62-35840 (JP, U) Japanese Utility Model Application Hei 1-144670 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 2/01, 2/12, 29/00

Claims (12)

(57) [Claims] 1. A recording head unit for discharging ink by using thermal energy to perform recording on a recording medium, comprising: a plurality of recording heads provided with a heating element for generating the thermal energy; A plurality of heat pipe portions for the print head provided for each of the plurality of print heads; a heat pipe connecting portion connecting the plurality of heat pipe portions; and a heat pipe connecting portion provided on both sides of the heat pipe connecting portion. A recording head unit comprising: a plurality of heating members; and a temperature sensor provided for each of the plurality of recording heads for controlling the operation of the heating members. 2. The printing head according to claim 1, wherein the heat energy generated by the heating element causes film boiling in the ink.
Ejecting ink along with the growth of bubbles due to the film boiling,
2. A recording method using the ink.
2. The recording head unit according to item 1. 3. A heat pipe connecting part is provided with a fan, and when any one of the temperature sensors for each of the heads exceeds a first predetermined temperature, the fan is driven;
The recording head unit according to claim 1, wherein the heating member is driven when at least one of the temperature sensors for each of the heads is equal to or lower than a second predetermined temperature lower than the first predetermined temperature. . 4. A voltage for preheating driving the heating member is set to a large voltage when the detected temperature is low in accordance with the detected temperature of the temperature sensor during a period from when the power is turned on until a recording operation is started, 3. The recording head unit according to claim 1, wherein control is performed to decrease the voltage as the detected temperature increases from the low case. 5. A recording apparatus for recording on a recording medium by discharging ink using thermal energy, wherein: a plurality of recording heads provided with a heating element for generating the thermal energy; A plurality of heat pipe sections for the recording head provided for each of the heads; a heat pipe connecting section for connecting the plurality of heat pipe sections; and a plurality of heating sections provided on both sides of the heat pipe connecting section. A temperature sensor provided for each of the plurality of recording heads for controlling the operation of the heating member; and a fan provided for the heat pipe coupling portion. If at least one of the temperature sensors exceeds a first predetermined temperature, the fan is driven, and any one of the temperature sensors for each of the heads is driven by the first temperature sensor.
A recording apparatus, wherein the heating member is driven when the temperature is equal to or lower than a second predetermined temperature lower than a predetermined temperature. 6. A recording apparatus according to claim 5, wherein said recording head is provided with a plurality of heating elements corresponding to the width of the recording material being conveyed. 7. The recording head causes film boiling in ink by thermal energy generated by the heating element,
Ejecting ink along with the growth of bubbles due to the film boiling,
The recording is performed with the ink.
Or the recording device according to 6. 8. A heating element for generating thermal energy, wherein the thermal energy is used to adjust the temperature of a plurality of recording heads for discharging ink to perform recording on a recording medium. In the temperature control device, a plurality of heat pipe portions for a print head provided for each of the plurality of print heads, a heat pipe connecting portion connecting the plurality of heat pipe portions, and both sides of the heat pipe connecting portion A temperature control device comprising: a plurality of heating members provided in each of the units; and a temperature sensor provided for each of the plurality of recording heads for controlling the operation of the heating members. 9. The heat pipe connection part has a flat part,
9. The temperature adjusting device according to claim 8, wherein the heating member is a planar heater disposed on the flat portion. 10. The temperature control device according to claim 8, wherein the heat pipe connecting portion has a flat portion, and the heating member is a bean heater arranged on the flat portion. 11. A fan is provided in the heat pipe connecting portion, and one of the temperature sensors for each of the heads is provided.
At least any one of the temperature sensors for each of the heads, and drives the heating member when any one of the temperature sensors of the heads is equal to or lower than a second predetermined temperature lower than the first predetermined temperature. 9. The method according to claim 8, wherein
11. The temperature adjustment device according to any one of 10. 12. According to a temperature detected by the temperature sensor until power is turned on and before a recording operation is started, a voltage for preheating driving the heating member is set to a large voltage when the detected temperature is low, 11. The temperature adjusting device according to claim 8, wherein a control is performed such that the voltage becomes smaller as the detected temperature increases from the low case.