JP2768508B2 - Ink jet recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus that performs recording by discharging ink from a recording head to a recording member.

[Conventional technology]

The ink jet recording method, which discharges ink from the recording head to record information such as characters and images, has lower operating noise than other recording methods, the basic mechanical structure is simple and inexpensive, and color printing Therefore, research and development have been widely promoted as a recording apparatus.

In recent years, an ink jet recording apparatus using a line type recording head, which enables a higher speed, has been known. However, in the case of ink jet recording, an ink ejection state changes depending on a substrate temperature of the recording head. In addition, it is necessary to control the substrate temperature to be constant, and in a line type recording head used for an ink jet system using a phase change of ink due to thermal energy, there is no unevenness in position of the recording head itself or a temporal temperature change. like,
A uniform and constant temperature control of the recording head is required.

For this reason, conventionally, as shown in FIG. 9, a discharge port (not shown) is provided on a line type recording head 51 provided over the entire width of a recording member. A heat pipe 52, which extends outside the recording area and has a heater 53 attached thereto, is attached.
A temperature sensor 55 is mounted at an appropriate position on the heat pipe 51, and a discharge portion of the heat pipe 52 is mounted on a fin 57 of a cooling means 54 including a radiating fin 57 and a fan 58. , The controller 56 as a drive control unit drives the heater 53 or the fan 58 to heat or cool the heat pipe 52 to control the temperature of the recording head 51.

On the other hand, in the case of using a plurality of line-type print heads, it is considered that the temperature control of each head can be performed well by controlling the above-mentioned one print head control method. As the temperature rises, there is a problem that heat is transferred between the heads to increase the temperature as a whole.

Therefore, when using a plurality of recording heads, as shown in FIG. 10, each of the recording heads 61a, 61b, 61c, 61d,
Heat pipes 62a, 62b, 62c, 62d, heaters 63a, 63b, 63c, 6
3d and the temperature sensors 65a, 65b, 65c, 65d are attached to the fins 67 of the common cooling means 64. And the controller
Reference numeral 66 denotes each recording head 61 from the temperature sensors 65a, 65b, 65c, 65d.
heaters 63a, 63b, 63 based on the temperatures of a, 61b, 61c, 61d
drive the heat pipes 62a, 62b, 62c, 62d
, Or the fan 68 of the common cooling means 64 is driven to cool the heat pipes 62a, 62b, 62c, 62d.

[Problems to be solved by the invention]

However, the main focus has been on controlling the temperature of the storage head using a heat pipe within a certain temperature range near a specified temperature. Therefore, since the degree of heating and heat radiation at this time cannot be extremely increased, there is a problem that it takes time to start up from the standby state (normal temperature) to the vicinity of the specified temperature. In particular, this problem becomes important when the length of the recording head is increased or when members such as fins are attached.

In addition, in the configuration shown in FIG. 10, in addition to the above problem, since the heat pipes mounted on a plurality of recording heads are mounted on a common cooling means, the temperature of a specific recording head rises and the temperature rises. When trying to lower the temperature, the fan of the common cooling means is driven, but in this case, the temperature of the recording head whose temperature has risen and the temperature of the other recording heads also decrease, and the temperature of the specific recording head is a predetermined temperature. , But the temperature of the other recording heads falls below a predetermined temperature. Therefore, it is necessary to drive the heater corresponding to the recording head whose temperature has decreased to increase the temperature of the recording head, resulting in an increase in the heat generated from the entire recording head, which consumes extra power for the recording apparatus. Accordingly, there is a problem that heat generation increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the related art, and uniformly raises a recording head to a specified temperature in a short time and keeps the recording head uniformly and precisely at a specified temperature when the temperature is near a specified temperature. It is an object of the present invention to provide an ink jet recording apparatus capable of performing the above.

It is another object of the present invention to provide an ink jet recording apparatus capable of controlling the temperature of each recording head uniformly and stably even when a plurality of recording heads are used.

[Means for solving the problem]

An ink jet recording apparatus according to the present invention is an ink jet recording apparatus that performs recording by discharging ink from a recording head to a recording member, the recording apparatus having a protruding portion attached to the recording head and protruding longer than the length of the recording head. A heat pipe, cooling means for the recording head provided on the projecting portion of the heat pipe, and heating means provided to variably switch the amount of heat applied to the recording head via the heat pipe. An ink jet recording unit, a temperature detecting means for detecting a temperature of the ink jet recording unit, and a drive control means for controlling the driving of the cooling means and the heating means based on a temperature detection value of the temperature detecting means. A first heating unit mainly used for starting up the recording head; After startup of the recording head, and having a second heating means is mainly used when performing a fine adjustment of the temperature of the recording head.

Some of the first heating means and the second heating means are provided on the back side of the heat pipe in contact with the recording head.

Some of the first heating means and the second heating means are provided at predetermined positions of the cooling means.

The first heating means may be provided at a predetermined location of the cooling means, and the second heating means may be provided on the back side of the heat pipe in contact with the recording head.

A plurality of the recording heads are provided, and the heat pipes are attached to each of the recording heads, and one end of the heat pipes is integrally fixed by a joining member that thermally connects the respective heat pipes. Some of the joining members are provided with the cooling means.

The recording head includes a thermal energy generating element as a discharge energy generator that generates thermal energy used for discharging ink, and utilizes a rapid pressure change generated by bubbles generated by the thermal energy. There is a device that ejects ink by using the following.

Some recording heads are provided with the discharge ports over the entire width of the recording member.

(Operation)

The ink jet recording apparatus of the present invention configured as described above heats and cools the recording head through the heat pipe, so that the heat medium in the heat pipe recirculates, so that the temperature of the recording head can be uniform and stable. Can control.

Heating means provided so as to variably switch the amount of heat applied to the recording head via the heat pipe increases the amount of heat applied to the recording head via the heat pipe at the time of startup, so that the recording head can be started up in a short time. Can be raised.

When each heat pipe is integrally fixed by a joining member, this joining member enables heat transfer between the recording heads to effectively utilize the heat of each recording head, and one cooling All recording heads of the means are allowed to cool.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1, 2, and 3 each show a main part of a first embodiment of the present invention, and 2 is a substrate member on which a thermal energy generating element (not shown) for applying thermal energy to ink is provided. Are provided corresponding to at least one orifice 3.

As shown in FIG. 2, the orifice 3 is
When thermal energy is applied to the ink from the thermal energy generating element according to an image signal, the ink is ejected from here. Reference numeral 4 denotes an ink chamber, which comprises an ink flow path and a common liquid chamber for supplying ink to the ink flow path, which are connected to the orifice 3 (both are not shown). The ink chamber 4 is supplied with ink from an ink reservoir (not shown). Reference numeral 13 denotes a support member which is partially fixed to the substrate member 4. 5 is a heat pipe,
A fin 6 for heat radiation is provided at an end, and a heater 7 for heating and a heater 12 for startup are provided on one side surface. Reference numeral 8 denotes a recording member, which is conveyed in the direction of arrow A by conveyance means (not shown). The recording head 1 is bonded to the heat pipe 5 and is directed to a method in which the orifice 3 faces the recording member 8. Ink is ejected from the orifice 3 onto the recording member 8 in accordance with an image signal, and an image is recorded. Reference numeral 9 denotes a fan which sends air to the fins 6 according to a command from a controller 11 which is a drive control means. The cooling means 14 is constituted by the fan 6 and the fins 9. The temperature sensor 10 is attached between the heat pipe 5 and the support member 13 and detects a temperature. The controller 11 is connected to the temperature sensor 10 and receives a temperature detected by the temperature sensor 10.

The controller 11 is also connected to the heater 7, the startup heater 12, and the fan 9, and the heater 7, the heater 12, and the fan 9 according to the temperature detected by the temperature sensor 10.
Adjust the input power or on / off time interval to the

 Next, the operation of this embodiment will be described.

When a recording operation start switch (not shown) is turned on,
First, the temperature of the support member 13 is detected by the temperature sensor 10. When the detected temperature is lower than a predetermined temperature (hereinafter, referred to as a specified temperature) which must be maintained during recording, for example, 50 ° C., the heater 7 and the start-up heater 12 are turned on, and the heat pipe 5 is turned on. Through the support member
Heat 13 At this time, the bonding side surface between the heat pipe 5 and the support member 13 serves as a condensing portion where the working fluid in the heat pipe 5 is liquefied, and the working fluid evaporated by heating from the heaters 7 and 12 spreads and condenses uniformly, and becomes uniform. In order to release latent heat, the support member 13 receives a uniform heat flux and the temperature rises uniformly and steeply.

When the temperature of the support member 13 reaches the specified temperature, the ink inside the orifice is adjusted by the recovery means (not shown), and the recording member 8 is transported in the direction of arrow A by the transport means (not shown). When the recording member 8 reaches a position facing the orifice 3 of the recording head 1, thermal energy is applied to the ink according to an image signal, and the ink is ejected from the orifice 3. When the ejected ink reaches the opposing recording member 8, it is absorbed and forms an image. As the image formation progresses, the temperature of the recording head 1 rises due to the heat remaining in the recording head 1 out of the thermal energy applied to the ink, and the temperature of the support member 13 also rises. At this time, the incubation sensor
When the detected temperature from 10 deviates from the specified temperature by more than an allowable amount, the controller 11 turns on the fan 9, sends air to the fins 6, and starts radiating heat from the recording head 1 via the heat pipe 5. At this time, the contact surface of the heat pipe 5 with the support member 13 becomes an evaporating portion, and a large amount of working fluid evaporates from a portion where the heat flux from the support member 13 is large, and according to the evaporation amount, Exposing a large amount of heat, a small amount of heat,
Turns into steam. In addition, for a portion where no heat flux flows, the working liquid that has once been vaporized condenses there to generate latent heat and supply heat. Since the steam portion has almost no thermal resistance and the amount of heat moves instantaneously, the interface temperature between the working liquid in the evaporation portion and the steam portion is instantaneously made uniform, and the heat flow flowing into the heat pipe 5 Even when the bundle has uneven locations, the interface temperature is maintained substantially uniform. Therefore, even if the heat flux having unevenness in the location flows into the support member 13 in accordance with the image signal, the support member 13 is maintained at a substantially uniform temperature by the action of the temperature equalization inside the heat pipe 5. Become. Then, even if the interface temperature is made uniform, the excess amount of heat is
Where it is condensed and generates heat. The generated heat is transmitted to the airflow sent from the fan 9 through the fins 6 and released into the air.

Then, the image recording operation is continued stably in a state where the temperature of the support member 13 is maintained almost uniformly near the specified temperature as described above by the controller 11 turning on and off the fan 9 appropriately according to the temperature detected by the temperature sensor 10. Can be

As described in detail above, by attaching a heat pipe to the recording head, and by heating or radiating the recording head through the heat pipe according to the temperature of the recording head,
The long recording head can be uniformly heated or uniformly radiated, and the long recording head can be stably controlled at a uniform temperature. As a result, the ink ejection state is dramatically stabilized, and the stability of the image is greatly improved. Further, in the configuration as in the present embodiment, since the installation positions of the fins and the fan can be located outside the image area, a strong airflow from the fan can be separated from the image area, and heat radiation can be performed without disturbing the flight path of the ejected ink. Yes, which further enhances image stability.

Here, FIG. 4 shows actual measurement data obtained by measuring the temperature change in the longitudinal direction of the support member 13 due to this heating at a plurality of locations of the support member 13.

In FIG. 4, the horizontal axis is heater 7 or heater 12
Indicates the time since the switch was turned on, and the vertical axis in FIG.
It indicates the temperature of the contact surface between the support member 13 and the heat pipe 5. The temperature detection points are three points at the position directly below the heater 7,
A position 10cm in the longitudinal direction from the position directly below the heater 7,
This is a position 20 cm apart from the position directly below the heater 7 in the longitudinal direction. The specified temperature is set to 50 ° C., and a detection point immediately below the heater is given to the controller 11 as a control temperature. Before startup, the temperature of the support member 13 is 28 ° C., the same as room temperature.

When the heater 7 and the heater 12 are used, the start-up is received by the controller 11, and the detected temperature of the temperature sensor 10 shown in FIG. 4A is 28 ° C., which is lower than the specified temperature (50 ° C.). As shown in FIGS. 8B and 8C, the controller 11 turns on the heaters 7 and 12 and turns off the heaters 7 and 12 when the temperature reaches a specified temperature (50 ° C.).
Thereafter, only the heater 7 is appropriately turned on and off so that the detected temperature becomes 50 ° C.

In the case where only the heater 7 is used, as shown in FIG. 4 (d), the control of the heater 12 for start-up is not performed (off state or the heater 12 is not attached).
The control for the same is the same.

Obviously, the heater 7 and the heater 12 have a shorter arrival time (rise time) to the specified temperature (50 ° C.) by half or less than the heater 7 alone. However, it is the same that almost no temperature difference occurs in the longitudinal direction, and the temperature after startup is suppressed to within ± 1 ° C. around the specified temperature.

In order to explain the effect of the heat pipe, an aluminum substrate having the same size as the heat pipe 5 is used instead of the heat pipe 5 in FIG.
The actual measurement data obtained with the same configuration as that of the embodiment of FIG.

In FIG. 5, the coordinate system and the temperature detection points are the same as in FIG. If the heat pipe 5 is not used, as shown in FIG. 5, a temperature difference of up to about 10 ° C. occurs in the longitudinal direction (in FIG. 4, there is almost no temperature difference). When the heat pipe 5 is not used, as shown in FIG. 5, a temperature oscillation of ± 7 ° to 8 ° C. occurs around the specified temperature immediately below the heater (± 1 ° C. in FIG. 4).

Thus, it can be seen that the use of the heat pipe 5 achieves the ideal control of the heating temperature of the support member 13 and the use of the start-up heater achieves the high-speed start-up.

FIG. 6 shows actually measured data when the recording head 1 of the embodiment of FIG. 1 is fully discharged, the fan 9 is appropriately turned on and off, and the temperature of the support member 13 is controlled to near the specified temperature by appropriate heat radiation. FIG. 7 shows similar execution data when half of the recording head 1 of FIG. 1 is ejected and half is in a non-ejection state. In both figures, the horizontal axis represents time, and the vertical axis represents the temperature at the interface between the support member 13 and the heat pipe 5. Room temperature is 26 ° C. After the support member 13 is heated by the heater 7 and controlled at 40 ° C., the time when the discharging operation is started is set as the origin. Fan 9
It turns on when the temperature of the support member 13 exceeds 41 ° C. and turns off when the temperature is 41 ° C. or less. In the case of full discharge, as shown in FIG. 6, by appropriately turning on and off the fan 9, the support member 13 can maintain the specified temperature almost stably. Needless to say, in this case, there is almost no temperature unevenness in the longitudinal direction. Next, in the case of half-discharge and half-non-discharge, as shown in FIG. 7, the temperature of the support member 13 is suppressed to a difference of about 1 ° C. and is stably maintained. This temperature difference is due to the thermal resistance of the wick inside the heat pipe 5, and the vapor-working fluid interface has a uniform temperature.
When the temperature reaches the surface of the heat pipe 5, this temperature difference occurs. However, the support member 13 of the non-discharge portion and the discharge portion
The temperature difference of 1 ° C is a temperature difference that causes almost no problem.
In this sense, when the recording head 1 is radiated through the heat pipe 5, the temperature of the support member 13 can be ideally and substantially uniformly controlled.

In the embodiment shown in FIG. 1, a heater 12 for start-up and a heater 7 for recording are provided on the heat pipe 5, and both are turned on at the time of start-up, and the heater 12 for start-up is turned off at the time of recording. Although the temperature of the support member 13 is controlled by turning on and off the fan 7 and the fan 9, the present invention is not limited to this.

For example, one heater increases the current to be injected at startup, increases the amount of heat generated, heats the heat pipe,
At the time of recording, it is easy to heat the heat pipe by switching the injected current to the same heater to reduce the amount of heat generation and reduce the amount of heat generated.

Further, the heater for startup may not be provided on the heat pipe and may be attached to the fin. However, attachment to a recording head is not preferable.

FIG. 8 shows the main parts of a second embodiment of the present invention,
Four recording heads 21a, 21b, 21c, 21d to which black, cyan, magenta, and yellow inks are respectively supplied are fixed to heat pipes 22a, 22b, 22c, 22d, respectively, and an orifice (not shown) is formed on the recording member 27. They are oriented in opposite directions. Black, cyan, magenta, and black, respectively, according to the image signals from the orifices of the recording heads 21a, 21b, 21c, and 21d.
The yellow image is ejected, and a color image is recorded on the recording member 27. The recording member 27 is transported in the direction of arrow A by transport means (not shown). Each heat pipe 22a, 22
One end of each of b, 22c, and 22d is elongated, and is fitted as a heat conductive block to a copper block 28, which is a thermally good conductor, so as to make good thermal contact. On the upper surface of the copper block 28, a heater 31 for start-up and recording heads 21a, 21b,
One heater 32 for temperature control during recording of 21c and 21d is fixed respectively. A fin 41 is fixed to the lower surface of the copper block 28, and a fan 42 for blowing air to the fin 41 is provided below the fin 41. The heater 31 and the heater 32 constitute a heating unit, and the fins 41 and the fan 42 constitute a cooling unit 40, respectively.The temperature sensor 25 embedded in the copper block 28, and the controller 26 serving as a drive control unit, Each recording head 21 is connected via each heat pipe 22a, 22b, 22c, 22d.
a, 21b, 21c, 21d are heated and cooled.

The copper block 28 includes one heater 31 and one heater.
At 32, not only can the four recording heads 21a, 21b, 21c, 21d be heated, but the heat of the respective recording heads 21a, 21b, 21c, 21d is transmitted, so that the temperature of each recording head 21a, 21b, 21c, 21d is increased. Has the function of averaging. Therefore, each recording head 21a,
When the recording states of the recording heads 21b, 21c, and 21d are offset, for example, even when recording (ejection) is performed on only one recording head 21a and the other three recording heads 21b, 21c, and 21d are not recording (ejection),
The heat of the one recording head 21a is changed to the other three recording heads 2a.
1b, 21c, 21d, four recording heads 21a, 21b, 21c, 21d
Maintaining an appropriate temperature as a whole and increasing the efficiency of electric power are performed. In general, when recording a color image, it is rare that three colors are simultaneously ejected (because simultaneous three colors are replaced with black ink by UCR processing). It is possible to design for full discharge power.

As a material of the heat conducting block 28, other than copper, aluminum or other good heat conductor such as the heat pipe itself may be used. Also,
As long as the print head is of a type that uses heat for which it is necessary to control the temperature of the print head to be constant, not only the above-described print head but also another print head may be used.

Next, the start-up of the recording heads 21a, 21b, 21c, 21d and the copper block 28 from the standby state to the recording state will be described.

Upon receiving the recording request, the controller 26 sets the temperature sensor 25
Temperature is lower than the specified temperature for recording (here, set to 50 ° C) at normal temperature (here, 28 ° C), so the heater 31 for start-up and the heater 32 for recording are turned on and the copper block 28 is heated. And heat pipes 22a, 22b, 22c, 22d
Instantaneously transfers heat to heat the recording heads 21a, 21b, 21c, 21d. When the detected temperature reaches the specified temperature, the controller 26
Turns off the heater 31 for start-up and the heater 32 for recording, and thereafter turns on and off the heater 32 for recording appropriately so that the detected temperature becomes a specified temperature (50 ° C.).

In the embodiment shown in FIG. 8, as in the embodiment shown in FIG. 1, by turning on both the heater for start-up and the heater for recording at the time of start-up, it is possible to start up in a short time and reach the specified temperature. Was. The same is true for the temperature difference that hardly occurs in the longitudinal direction, and that the temperature can be controlled to a substantially constant temperature range around the specified temperature after reaching the specified temperature.

In the embodiment of FIG. 8, the heater is composed of two heaters and the heating amount is switched.
It is also possible to configure one heater and control the amount of heating by switching the current flowing through the heater.

As described above, the present invention brings about an excellent effect particularly in a recording head and a recording apparatus of a bubble jet method among ink jet recording methods. Regarding the typical 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 the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). That corresponds to the recorded information on the electrothermal transducer
Applying at least one drive signal that provides a rapid temperature rise to obtain nucleate boiling causes the electrothermal transducer to generate thermal energy, causing nucleate boiling on the heat-acting surface of the recording head, resulting in this drive. This is effective because bubbles in liquid (ink) can be formed in one-to-one correspondence with signals. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the gas, at least one liquid 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 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. 4,462,259 and 4,434,262 are suitable. If the conditions described in the specification of 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 the configuration of the recording head, in addition to the combination configuration of the discharge port and the liquid path electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above specification, the heat acting portion is bent. A configuration using U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration arranged in a region where the region is located, is also included in the present invention. JP-A-59 / 123670 discloses a configuration in which a slit common to a plurality of electrothermal transducers is used as a discharge junction of electrothermal transducers.
The effect of the present invention is also effective in a configuration based on Japanese Patent Application Laid-Open No. 138461/1984, which discloses a configuration in which an opening for absorbing a pressure wave of thermal energy corresponds to a discharge portion. Further, as a full line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus,
As disclosed in the above specification, any combination of a plurality of recording heads may be used to satisfy the length or a single recording head integrally formed. The above effects can be more effectively exhibited. In addition, it is provided integrally with a replaceable chip-type recording head or the recording head itself, which can be electrically connected to the apparatus main body and supplied with ink from the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a cartridge type recording head is used. Further, it is preferable to add recovery means for the printhead provided as a configuration of the printing apparatus, preliminary auxiliary means, and the like, since the effects of the present invention can be further stabilized. If these are specifically raised, capping means for the recording head, cleaning means, pressurizing or suction means, an electrothermal transducer or a preheating means using a pressurizing element or a combination thereof separately from these, and separate from recording It is also effective to perform a preliminary ejection mode in which the ejection is performed in order to perform stable printing. Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be configured integrally with the recording head or by combining a plurality of recording heads. The present invention is also very effective for an apparatus provided with at least one of the above.

〔The invention's effect〕

As described above, the present invention can control the temperature of a long recording head uniformly and stably by heating and cooling the recording head through a heat pipe, stabilizing the ink ejection state, and Stability is improved. Further, since the heat pipe is used, it is not necessary to adjust the size of the heating means to the size of the recording head or to uniformly control the heating means with a plurality of heating means, so that the cost is reduced and the configuration is simplified.

Heating means provided so as to variably switch the amount of heat applied to the recording head via a heat pipe can shorten the rise time required to enter a recording state after a recording request, thereby achieving high-speed image output. Can be made possible. Further, after the elapse of the rise time, the amount of heat of the heating means can be reduced, and there is an effect that the power of heating and heat radiation can be made more efficient (energy saving).

In the case where each heat pipe is integrally fixed by a joining member, the heat can be conducted between the recording heads, and the heating amount can be switched between startup and recording by the heating means. This makes it possible to shorten the time required for each recording head to reach a specified temperature, and to uniformly control the recording head to a constant temperature during recording. As a result, the following effects (1) to (5) are obtained.

(1) A plurality of recording heads can be cooled by one cooling unit, and the size and cost of the apparatus can be reduced.

(2) Efficiency of power for heating and heat radiation can be improved.

(3) The maximum power of heat radiation can be reduced, and the cooling means can be reduced.

(4) The distance between the recording heads can be reduced by the above (1) and (3), which is advantageous for registration.

(5) The time from recording request to image output can be shortened,
In addition, it is possible to record a stable image.

[Brief description of the drawings]

1 is a perspective view showing a main part of a first embodiment of the present invention, FIGS. 2 and 3 are partial perspective views of FIG. 1 respectively, and FIG. 4 is a heater of the embodiment of FIG. 7 is a graph showing a comparison result between a heater using the heater 12 and a heater using only the heater 7, and FIG. 5 shows a temperature change at the time of start-up of an example using an aluminum substrate instead of the heat pipe 5. 6 and 7 are graphs each showing a temperature change at the time of recording in the embodiment of FIG. 1, and FIG. 8 is a second graph of the present invention.
9 and 10 are partial perspective views showing a conventional example, respectively. 1, 21a, 21b, 21c, 21d: print head, 2: substrate member, 3: orifice, 4: ink chamber, 5,22a, 22b, 22c, 22d: heat pipe, 6,41 ... Fins, 7, 12, 31, 32, ... heater, 8, 27 ... recording member, 9, 42 ... fan, 10, 25 ... temperature sensor, 11, 26 ... controller, 13 ... support member , 14,40 ... cooling means, 28 ... copper block.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshihiko Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Ken Doi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Shujiro Kadowaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masafumi Watani 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 56) References JP-A-62-55180 (JP, A) JP-A-57-117673 (JP, A) JP-A-60-73861 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , (DB name) B41J 2/175 B41J 2/335

Claims (7)

(57) [Claims] 1. An ink jet recording apparatus for performing recording by discharging ink from a recording head to a recording member, comprising: a heat pipe mounted on the recording head and having a protrusion protruding longer than the length of the recording head; A cooling means for the recording head provided at the projecting portion of the heat pipe; and a heat amount provided to the recording head via the heat pipe so as to be variably switched. An ink jet recording unit comprising: a first heating unit mainly used for the main unit; and a second heating unit mainly used when finely adjusting the temperature of the recording head after the start of the recording head. Temperature detecting means for detecting the temperature of the ink jet recording unit; and the cooling means based on a temperature detection value of the temperature detecting means. An ink jet recording apparatus characterized by comprising a drive control means for controlling the driving of the serial heating means. 2. The apparatus according to claim 1, wherein said first heating means and said second heating means are provided on a back side of said heat pipe which is in contact with said recording head. Inkjet recording device. 3. An ink jet recording apparatus according to claim 1, wherein said first heating means and said second heating means are provided at predetermined positions of said cooling means. 4. A method according to claim 1, wherein said first heating means is provided at a predetermined position of said cooling means, and said second heating means is provided on a back side of said heat pipe in contact with said recording head. The ink jet recording apparatus according to claim 1, wherein: 5. The recording head according to claim 1, wherein a plurality of recording heads are provided.
The heat pipe is attached to each of the recording heads,
2. The heat pipe according to claim 1, wherein one end of the heat pipe is integrally fixed by a joining member that thermally connects the heat pipes, and the joining member is provided with the cooling unit. 3.
The ink jet recording apparatus according to any one of claims 1 to 4, wherein 6. The recording head has a thermal energy generating element as a discharge energy generator for generating thermal energy used for discharging ink, and a sudden pressure change is caused by bubbles generated by the thermal energy. The ink jet recording apparatus according to any one of claims 1 to 5, wherein the ink is ejected by utilizing the ink jet recording method. 7. The ink jet recording apparatus according to claim 1, wherein the recording head is provided with the discharge port over the entire width of the recording member.