JPH10775A - Ink jet image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly regulate the temp. of a printing head or ink by providing a temp. regulating means regulating the temp. of the printing head to a carriage in contact with the printing head. SOLUTION: A passage member 20 consisting of a tube 16, the tubes 18 connected to both ends of the tube 16 and the plate 18a fixed to the tubes 18 to come into contact with a base plate 14 is fixed to a carriage 12 loaded with a printing head 10. A motor 22 and the gears 24a-24f rotated by the motor 22 are fixed to the carriage 12 and, when the gears 24a-24f are rotated by the rotation of the motor 22, a liquid is circulated within the tubes 16, 18. For example, water of room temp. is circulated, the base plate 14 is cooled and the surface 14 exposed to the outside of the base plate 14 and the silicon plate formed on the opposite surface thereof are also cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet type image forming apparatus for forming an image on a recording medium such as recording paper by ejecting ink from the print head while reciprocating a carriage on which the print head is mounted in a predetermined direction. Related to the device.

[0002]

2. Description of the Related Art As one of output devices of computers and workstations, there is known an ink jet type image forming apparatus which forms an image on recording paper by discharging ink. This inkjet type image forming apparatus includes, for example,
A print head having a plurality of discharge nozzles for discharging ink, a carriage mounted with the print head and reciprocating in a predetermined direction, and a transport device for transporting recording paper in a direction orthogonal to the predetermined direction are provided. ing. When an image is formed on a recording sheet, the recording sheet being conveyed by the conveyance device is temporarily stopped, and the carriage is reciprocated in the above-described predetermined direction. Ink is ejected from the ejection nozzles to form (print) an image for one band in the portion located at the position, and then the recording paper is conveyed by a predetermined length, and the next portion is newly located in the image forming area. The operation of forming an image for the band is repeated.

The above-described print head usually includes a silicon plate on which a plurality of discharge nozzles are formed, and near the respective discharge nozzles inside the silicon plate,
A heating element for discharging ink from each of the plurality of discharge nozzles is formed. The print head also includes an aluminum base plate that overlaps the silicon plate and reinforces the silicon plate. In the print head having such a configuration, the temperature of the print head or the ink rises every time the heating element generates heat to discharge ink from the discharge nozzle.

When the temperature of the ink changes, the viscosity of the ink changes. Since the viscosity of the ink affects the flow resistance when the ink is ejected from the ejection nozzles, if the viscosity of the ink changes, the amount of the ejected ink changes, resulting in uneven image density. Further, when the temperature of the ink rises to near the boiling point of the ink, bubbles are generated in the ink, and the ink cannot be supplied to the discharge nozzle due to the bubbles, so that the ink cannot be discharged. Therefore, in order to prevent image density unevenness and ink ejection failure, when the temperature of the print head exceeds a predetermined temperature, printing is stopped or blown to the print head to lower the temperature of the print head.

[0005]

However, in natural cooling or air cooling in which the print head is cooled by stopping printing or blowing air to the print head, there is a possibility that the temperature of the print head slows down and the print head cannot be sufficiently cooled. is there.

Incidentally, when the temperature of the print head or the ink is low in winter or the like, the viscosity of the ink increases. In this case, the flow resistance when ejecting ink from the ejection nozzle is large, and the amount of ejected ink is reduced. As a countermeasure against this, there is known a technique in which a heater for temperature control is arranged inside the print head, and the print head is heated by the heater so that the print head stands by at a predetermined standby position until the ink has a viscosity that allows proper printing. ing. However, in this technique, since the heater is provided inside the print head, the structure of the print head is complicated, and the heater cannot be provided at an appropriate position due to the layout, and the print head and the ink are sufficiently supplied. Heating may not be possible.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an ink jet type image forming apparatus capable of appropriately adjusting the temperature of a print head and ink with a relatively simple structure.

[0008]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising:
A plurality of ejection nozzles for ejecting ink are formed, and a heating element for ejecting ink from each of the plurality of ejection nozzles is arranged in the vicinity of each of the plurality of ejection nozzles. A carriage reciprocating in a predetermined direction, wherein the carriage reciprocates in the predetermined direction and discharges ink from the discharge nozzles to form an image on a recording medium. A temperature control means for controlling the temperature of the print head, which is fixed and comes into contact with the print head, is provided.

Here, (2) the temperature control means circulates a heating medium or a cooling medium inside the temperature control means, and (3) the ink jet type image forming apparatus includes: It is preferable to provide a medium supply unit that supplies a heating medium or a cooling medium.

(4) It is preferable that the medium supply means is mounted on the carriage.

(5) The medium supply means is arranged in an area where the carriage reciprocates.
(6) Preferably, the carriage moves to the medium supply unit when the temperature adjustment unit is used.

(7) The temperature control means circulates a heating medium or a cooling medium inside the temperature control means, and the ink jet type image forming apparatus comprises: (8) a rack extending in the predetermined direction. And a guide rail (9) for guiding the carriage in the predetermined direction. The guide rail engages with the rack and rotates to circulate a heating medium or a cooling medium inside the temperature control means. It is preferable to provide a gear set.

(10) It is preferable that a heating / cooling means for heating or cooling a heating medium or a cooling medium circulating inside the temperature control means is provided in the circulation path.

Further, (11) the print head has a heat conductive base plate disposed near the heating element and exposed to the outside. (12) The temperature control means is provided to expose the base plate. It is preferable that it comes into contact with the part.

(13) It is preferable that the medium supply means or the heating / cooling means is operated or stopped based on the temperature of the print head.

(14) The ink jet type image forming apparatus further comprises a recovery device for recovering an ink discharge state of the print head by discharging or sucking ink from the print head, and (15) the temperature control. Preferably, the means uses the ink discharged or sucked by the recovery device as a heating medium or a cooling medium.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an ink jet type image forming apparatus according to the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a perspective view showing a schematic configuration of a plotter which is an example of an ink jet type image forming apparatus of the present invention.

The plotter 1 is fixed to an upper part of a stand 2 with casters 2a. The plotter 1 includes an operation unit 3 for operating the plotter 1. By operating various switches and the like provided on the operation unit 3, paper size, online / offline, commands, and the like are instructed. You. The recording paper inserted into the recording paper insertion slot 4 in the direction of arrow A is conveyed into the plotter 1 based on an instruction from the operation unit 3, where an image is printed and discharged. Further, the plotter 1 includes a cover 5 that covers the inside thereof. When the cover 5 is opened, a guide rail 13 (see FIG.
3 is reciprocated in the direction of arrow B guided by the carriage 3
Can be seen.

The carriage and print head of the plotter 1 will be described with reference to FIG.

FIG. 2 is a perspective view showing a carriage on which a print head is mounted.

A carriage 12 on which a print head 10 containing black ink is mounted is fixed to a belt (not shown) that reciprocates in the direction of arrow B. When the belt reciprocates in the arrow B direction, the carriage 12 is also guided by the guide rail 13 and reciprocates in the arrow B direction.

The print head 10 includes an aluminum base plate (an example of a heat conductive base plate according to the present invention) 14.
4 is exposed outside. In addition, a silicon plate (or a glass plate, not shown) is provided on the surface of the base plate 14 opposite to the surface 14a exposed to the outside.
Are formed on top of each other. This silicon plate has
An ink pad for storing ink and a plurality of ejection nozzles formed downward from the ink pad are formed. An ejection heater (an example of a heating element according to the present invention) for ejecting ink from each of the plurality of ejection nozzles is formed on the silicon plate near the ejection nozzle. Since the area near half of the discharge nozzle is in contact with the silicon plate, every time the discharge heater is heated and ink is discharged from the discharge nozzle, the heat of the discharge heater is transmitted through the silicon plate and the base plate 1 is heated.
4 increases with the temperature of the ink.

The carriage 12 has a rubber tube 1 attached thereto.
6, an aluminum tube 18 connected to both ends of the tube 16, and an aluminum plate 18 a fixed to the tube 18 and in contact with the base plate 14 (a temperature member according to the present invention). 20 (which is an example of an adjusting means) is fixed, and the tube 16 and the tube 18 are fixed.
A liquid such as water circulates in the inside. Here, the tube 16 is made of rubber, but may be formed of another elastic member. The tube 18 is made of another material having high thermal conductivity,
For example, it may be formed from a metal such as copper, brass, iron or an alloy material. Further, the flow path member 20 may be detachably fixed to the carriage 12.

Further, a motor 22 is mounted on the carriage 12.
And a gear group 24 rotated by the motor 22
Has been fixed. A gear 24a is fixed to a rotating shaft 22a of the motor 22, and the gear 24a is a gear 24b.
And are engaged. The gear 24c and the gear 24d are fixed coaxially with the gear 24b, and the gear 24c meshes with the gear 24e. A gear 24f is fixed coaxially with the gear 24e. The tube 16 is formed by the gear 24d and the gear 24f.
Gear group 2 is rotated by the rotation of the motor 22.
4 gears 24a, 24b, 24c, 24d, 24e,
When 24f rotates, the tube 16 is compressed or restored by the gear 24d and the gear 24f, so that the liquid circulates inside the tube 16 and the tube 18. As this liquid, for example, when room temperature water is circulated, the base plate 1
4 is cooled, whereby the silicon plate on which the discharge nozzles and discharge heaters are formed is also cooled. As a result,
The temperature of the ink contained in the print head 10 can be appropriately adjusted, and uneven image density and inability to eject ink can be prevented. Here, the water circulating inside the tubes 16 and 18 is an example of the cooling medium according to the present invention.

In forming an image on the recording paper, the recording paper is placed on a platen (not shown), and a carriage drive motor (not shown) is operated to reciprocate the carriage 12 in the direction of arrow B. An image signal carrying image information is input to the print head 10, and based on the image signal, the ejection heater is heated to eject ink from the ejection nozzles, thereby forming an image on recording paper. Each time ink is ejected, the temperature of the base plate 14 is increased by the heat from the ejection heater. The motor 22 is operated at the same time when the above-described image signal is input to the print head 10. By the operation of the motor 22, as described above, the liquid circulates inside the flow path member 20 to cool the base plate 14, thereby also cooling the silicon plate, and the temperature of the ink contained in the print head 10. Can be adjusted appropriately, and uneven image density and inability to eject ink can be prevented.

If a temperature sensor is installed in the print head 10 and the motor 22 is driven when the ink temperature is high based on the temperature detected by the temperature sensor, the Since the gears of the gear group 24 do not rotate without driving the motor 22, the liquid does not circulate inside the tubes 16 and 18, and the print head 10 is not excessively cooled. As a result, the ink temperature can be adjusted so as to be properly maintained, which is more effective. Thus, by rotating the gear group 24 based on the temperature of the print head 10, cooling or heating of the print head 10 is promoted, and the print head 10 can be adjusted to an appropriate temperature. [Second Embodiment] A second embodiment of the ink jet type image forming apparatus of the present invention will be described with reference to FIG. FIG.
3 is a perspective view showing a carriage on which a print head is mounted, and the same components as those in FIG. 2 are denoted by the same reference numerals.

The difference between the second embodiment shown in FIG. 3 and the first embodiment shown in FIG.
A circulating fluid tank 30 is installed.
The point is that a circulating liquid heating / cooling device 32 (for example, a heating / cooling unit according to the present invention) including a heater and an electronic cooling element is provided in the area 0.

In forming an image on the recording paper, the recording paper is placed on a platen (not shown), and a carriage driving motor (not shown) is operated to reciprocate the carriage 12 in the direction of arrow B. An image signal carrying image information is input to the print head 10, and based on the image signal, the ejection heater is heated to eject ink from the ejection nozzles, thereby forming an image on recording paper. Each time ink is ejected, the temperature of the base plate 14 rises. At the same time when an image signal is input to the print head 10, the motor 22 is operated to circulate the circulating fluid inside the tubes 16 and 18. The liquid heating / cooling device 32 is also operated to cool the circulating liquid. As a result, the cooled circulating fluid circulates inside the tubes 16 and 18 to cool the base plate 14, thereby cooling the silicon plate and appropriately adjusting the temperature of the ink contained in the print head 10. It is possible to prevent image density unevenness and ink ejection failure.

A temperature sensor is installed in the print head 10, and based on the temperature detected by the temperature sensor, the circulating fluid heating / cooling device 32 is operated so as to cool the circulating fluid when the ink temperature is high. When the ink temperature is low, the circulating fluid heating / cooling device 3 heats the circulating fluid.
2 can be adjusted to maintain the ink temperature more appropriately. Thus, the print head 1
By operating the circulating fluid heating / cooling device 32 based on the temperature of 0, cooling or heating of the print head 10 is promoted, and the print head 10 can be adjusted to a more appropriate temperature. Here, the heated circulating liquid is an example of the heating medium according to the present invention, and the cooled circulating liquid is an example of the cooling medium according to the present invention.

Further, the temperature of the print head may be predicted from image information or the like without installing a temperature sensor in the print head, and the circulating fluid heating / cooling device 32 may be operated based on this temperature. Third Embodiment A third embodiment of the ink jet type image forming apparatus of the present invention will be described with reference to FIG.

FIG. 4 is a perspective view showing a carriage on which a print head is mounted, and the same components as those in FIG. 2 are denoted by the same reference numerals.

The third embodiment shown in FIG. 4 is different from the first embodiment shown in FIG. 2 in that a rack is formed on a guide rail and a gear that meshes with the rack is provided on a carriage.

The plotter of the third embodiment has a guide rail 40 on which a rack 40a extending in the direction of arrow B is formed. A gear group 42 is fixed to the carriage 12, and the gear 42a meshes with the rack 40a. Therefore, when the carriage 12 reciprocates in the arrow B direction, the gear 42a rotates. Gears 42b and 42d are mounted coaxially with the gear 42a.
Are engaged with the gear 42c. A gear 42e is mounted coaxially with the gear 42c. Gear 42d and gear 42
e sandwich the tube 16 between the carriage 12
Reciprocates in the direction of arrow B to rotate the gear 42a, and the other gears 42b, 42c, 42d, 42e also rotate.
As a result, the tube 16 is connected between the gear 42d and the gear 42e.
Is compressed or restored, so that liquid circulates inside the tubes 16 and 18. For example, when water at room temperature is circulated as this liquid, the base plate 14 is cooled, thereby cooling the silicon plate on which the discharge nozzles and discharge heaters are formed. As a result, the temperature of the ink contained in the print head 10 can be appropriately adjusted, and uneven image density and inability to eject ink can be prevented. Here, the water circulating inside the tubes 16 and 18 is an example of the cooling medium according to the present invention.

In forming an image on the recording paper, the recording paper is placed on a platen (not shown), and a carriage drive motor (not shown) is operated to reciprocate the carriage 12 in the direction of arrow B. An image signal carrying image information is input to the print head 10, and based on the image signal, the ejection heater is heated to eject ink from the ejection nozzles, thereby forming an image on recording paper. Each time ink is ejected, the temperature of the base plate 14 increases, but as described above, the gear 42a rotates and the gears 42d and 42e rotate as the carriage 12 reciprocates in the direction of arrow B. Therefore, the liquid circulates inside the tubes 16 and 18 to cool the base plate 14, thereby cooling the silicon plate and appropriately adjusting the temperature of the ink contained in the print head 10, resulting in uneven image density. And ink ejection failure can be prevented. In addition, since the liquid is circulated inside the tubes 16 and 18 using the reciprocating motion of the carriage 12, no extra driving source is required. Fourth Embodiment A fourth embodiment of the ink jet type image forming apparatus of the present invention will be described with reference to FIG.

FIG. 5 is a perspective view showing a carriage on which a print head is mounted, and the same components as those in FIG. 4 are denoted by the same reference numerals.

The difference between the fourth embodiment shown in FIG. 5 and the third embodiment shown in FIG.
A circulating fluid tank 50 is installed.
The point is that a circulating fluid heating / cooling device 52 (e.g., a heating / cooling unit according to the present invention) including, for example, a heater and an electronic cooling element is provided in the area 0.

In forming an image on the recording paper, the recording paper is placed on a platen (not shown), and a carriage drive motor (not shown) is operated to reciprocate the carriage 12 in the direction of arrow B. An image signal carrying image information is input to the print head 10, and based on the image signal, the ejection heater is heated to eject ink from the ejection nozzles, thereby forming an image on recording paper. Each time ink is ejected, the temperature of the base plate 14 increases, but as described above, the gear 42a rotates and the gears 42d and 42e rotate as the carriage 12 reciprocates in the direction of arrow B. Therefore, the liquid circulates inside the tubes 16 and 18 to cool the base plate 14, thereby cooling the silicon plate, and appropriately adjusting the temperature of the ink contained in the print head 10. And ink ejection failure can be prevented.

A temperature sensor is installed in the print head 10, and based on the temperature detected by the temperature sensor, the circulating fluid heating / cooling device 52 is operated so as to cool the circulating fluid when the ink temperature is high. When the ink temperature is low, the circulating fluid heating / cooling device 5 heats the circulating fluid.
2 can be adjusted to maintain the ink temperature more appropriately. Thus, the print head 1
By operating the circulating fluid heating / cooling device 52 based on the temperature of 0, cooling or heating of the print head 10 is further promoted, and the print head 10 can be maintained at a more appropriate temperature. The temperature of the print head may be predicted from image information or the like without installing a temperature sensor on the print head, and the circulating fluid heating / cooling device 52 may be operated based on this temperature. Here, the heated circulating fluid is an example of the heating medium according to the present invention, and the cooled circulating fluid is
It is an example of a cooling medium according to the present invention. [Fifth Embodiment] A fifth embodiment of the ink jet type image forming apparatus of the present invention will be described with reference to FIG.

FIG. 6 is a perspective view showing a carriage on which a print head is mounted, and the same components as those in FIG. 2 are denoted by the same reference numerals.

A plate 18a is in contact with the base plate 14 of the print head 10, and a tube 18 is fixed to the plate 18a. A tube 16a and a tube 16b are connected to both ends of the tube 18, respectively. At one end of the carriage 12 within the range of reciprocation, a circulating liquid tank 60 (which is an example of a medium supply unit according to the present invention) filled with a circulating liquid 62 is provided. Circulating fluid tank 60
Is provided with a tube 64 for supplying the circulating fluid 62 to the tube 16b. When the carriage 12 comes near the circulating fluid tank 60, the tube 16b and the tube 64 are connected to each other. . A valve is provided at one end of the tube 16b connected to the tube 64 so that the circulating fluid does not overflow when the tube 64 comes off. The circulating fluid tank 60
Is provided with a motor 66 and a gear group 68 for sucking up the circulating fluid 62 in the circulating fluid tank 60. Motor 6
A gear 68a is fixed to the rotation shaft 66a of the sixth gear 6, and the gear 68a is engaged with the gear 68b. Gear 68
A gear 68c is mounted coaxially with the gear a.
A gear 68d is mounted coaxially with b. Gear 68
c and the gear 68d sandwich the tube 64, and the rotation of the motor 66 causes the gears 68a, 68
When b, 68c and 68d rotate, the gear 68c and the gear 6
8d, the tube 64 is compressed or restored, so that the tube 64 sucks up the circulating fluid 62 and the tube 1
6b. The circulating fluid supplied to the tube 16b passes through the tube 18 and the tube 16a and passes through the circulating fluid tank 6.
Return to 0. As the circulating liquid 62, water may be used, or waste ink not used for printing may be used.

In forming an image on the recording paper, the recording paper is placed on a platen (not shown), and a carriage drive motor (not shown) is operated to reciprocate the carriage 12 in the direction of arrow B. An image signal carrying image information is input to the print head 10, and based on the image signal, the ejection heater is heated to eject ink from the ejection nozzles, thereby forming an image on recording paper. Each time ink is ejected, the temperature of the base plate 14 rises, but at the end of all printing or at the end of one-line printing, the tube 16b and the tube 64 are connected to operate the motor 66, and the tubes 16a, 16b, The circulating liquid 62 is circulated inside the pipe 18 to cool the base plate 14. Thereby, the silicon plate is also cooled, the temperature of the ink contained in the print head 10 can be appropriately adjusted, and unevenness in image density and inability to eject ink can be prevented. If a high-temperature liquid is contained as the circulating liquid, the print head can be warmed, which is convenient in winter and the like.

If a temperature sensor is installed in the print head 10 and the tube 16b and the tube 64 are connected based on the temperature detected by the temperature sensor when the ink temperature is high, the ink temperature can be reduced. When low, the carriage 12 is not connected without moving, so that the circulating fluid does not circulate inside the tubes 16a, 16b and the tube 18, and the print head 10 is not excessively cooled. As a result,
It can be adjusted to keep the ink temperature more properly. Thus, by connecting the tube 16b and the tube 64 based on the temperature of the print head 10, cooling or heating of the print head 10 is promoted, and the print head 10 is cooled.
Can be maintained at an appropriate temperature. The temperature of the print head may be predicted from image information or the like without installing a temperature sensor in the print head, and the tube 16b and the tube 64 may be connected based on this temperature. Sixth Embodiment A sixth embodiment of the ink jet type image forming apparatus of the present invention will be described with reference to FIG.

FIG. 7 is a perspective view showing a carriage on which a print head is mounted, and the same components as those in FIG. 6 are denoted by the same reference numerals.

A feature of the sixth embodiment shown in FIG. 7 resides in that the temperature of the print head is adjusted by using a recovery device that recovers the ink discharge state of the print head by discharging ink from the print head.

The carriage 12 has a rubber tube 70,
An aluminum tube 18 is connected to each end of the tubes 70 and 72. Although the tubes 70 and 72 are made of rubber, they may be formed of other elastic members. At one end within the range of reciprocation of the carriage 12, there is provided a recovery device 80 for forcibly discharging ink from the print head 10 to recover the ink discharge state of the print head. The recovery device 80 includes a cap 8 that covers a discharge nozzle (not shown) of the print head 10.
2 and a valve 84 for sealing the cap 82. The recovery device 80 includes a rubber tube 86 connected to the cap 82, a three-way valve 88 connected to one end 86 a of the tube 86, and a rubber tube connected to one end 90 a to the three-way valve 88. 90. The other end 90 b of the tube 90 is located above the waste ink tank 92. Further, the recovery device 80 includes the print head 10
A motor 94 and a gear group 96 for sucking ink from the discharge nozzles are provided. A gear 96a is fixed to a rotation shaft 94a of the motor 94, and the gear 96a is engaged with a gear 96b. The gear 96 is coaxial with the gear 96a.
c is attached and the gear 96 is coaxial with the gear 96b.
d is attached. The tube 90 is sandwiched between the gears 96c and 96d, and the gears 96a, 96b, 96c, 96 of the gear group 96 are rotated by the rotation of the motor 94.
When d rotates, the tube 90 is compressed or restored by the gears 96c and 96d, so that the ink is sucked from the discharge nozzles and discarded in the waste ink tank 92. The ink 63 discarded in the waste ink tank 92 is sucked up from one end 70a of the tube 70 and
0, the tube 18, the tube 72, the three-way valve 88, and the tube 90, and return to the waste ink tank 92. When the waste ink tank 92 does not have a sufficient amount of the waste ink 63, water or the like may be stored in the waste ink tank 92 in advance.

To form an image on the recording paper, the recording paper is placed on a platen (not shown), and a carriage drive motor (not shown) is operated to reciprocate the carriage 12 in the direction of arrow B. An image signal carrying image information is input to the print head 10, and based on the image signal, the ejection heater is heated to eject ink from the ejection nozzles, thereby forming an image on recording paper. Each time ink is ejected, the temperature of the base plate 14 rises. When the motor 94 is driven, the waste ink 63 flows through the tubes 70, 18, 72, the three-way valve 88, and the tube 90, and the base plate 14 Cooling. Thereby, the silicon plate is also cooled, the temperature of the ink contained in the print head 10 can be appropriately adjusted, and unevenness in image density and inability to eject ink can be prevented. Further, the waste ink 63 stored in the waste ink tank 92 does not have to be wasted.

If a temperature sensor is installed in the print head 10 and the motor 94 is driven when the ink temperature is high based on the temperature detected by the temperature sensor, when the ink temperature is low, Since the gears of the gear group 96 do not rotate without driving the motor 94, waste ink does not flow through the tubes 70, 18, the tube 72, the three-way valve 88, and the tube 90. As a result, the ink temperature can be adjusted so as to maintain it more appropriately. Thus, by rotating the gear group 96 based on the temperature of the print head 10, cooling or heating of the print head 10 is promoted, and the print head 10 can be maintained at an appropriate temperature. Further, the temperature of the print head may be predicted from image information or the like without installing a temperature sensor in the print head, and the motor 94 may be operated based on this temperature.

[0048]

As described above, according to the ink jet type image forming apparatus of the present invention, the temperature control means for controlling the temperature of the print head is fixed to the carriage and is in contact with the print head. The temperature of the print head and ink can be appropriately adjusted with a simple structure.

Here, the temperature adjusting means is a means for circulating a heating medium or a cooling medium inside the temperature adjusting means, and the ink jet type image forming apparatus is provided with a temperature adjusting means arranged in the main body thereof. When a medium supply means for supplying a heating medium or a cooling medium is provided, the temperature of the print head and the ink can be adjusted efficiently.

When the medium supply means is mounted on a carriage, space can be saved.

In the case where the medium supply means is arranged in an area where the carriage reciprocates, and the carriage moves to the medium supply means when the temperature adjusting means is used, it is more suitable. The temperature of the print head and ink can be adjusted.

The temperature control means circulates a heating medium or a cooling medium inside the temperature control means, and the ink jet type image forming apparatus has a rack which extends in a predetermined direction. When a gear rotatably fixed to the carriage is provided, which circulates the heating medium or the cooling medium inside the temperature adjusting means by engaging with the guide rail to be guided and rotating in the rack, the reciprocating motion of the carriage is used. Then, the heating medium or the cooling medium is circulated inside the temperature adjusting means, so that an extra drive source is not required.

When a heating / cooling means for heating or cooling a heating medium or a cooling medium circulating inside the temperature adjusting means is provided in the circulation path, the temperature of the print head and the ink can be more easily adjusted.

Further, in the case where the print head has a heat conductive base plate disposed near the heating element and exposed to the outside, and the temperature control means is in contact with the exposed portion of the base plate, The temperature of the print head can be adjusted more efficiently.

Further, when the medium supply means or the heating / cooling means is operated or stopped based on the temperature of the print head, the heating medium or the cooling medium is circulated only when the temperature adjustment is necessary. Good adjustment efficiency.

Further, the ink jet type image forming apparatus has a recovery device for recovering the ink discharge state of the print head by discharging or sucking ink from the print head, and the temperature adjusting means causes the recovery device to discharge or suck ink. When the used ink is used as a heating medium or a cooling medium, the ink ejected by the recovery device does not needlessly be discarded.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a plotter which is an example of an inkjet type image forming apparatus of the present invention.

FIG. 2 is a perspective view showing a characteristic portion of the first embodiment of the inkjet type image forming apparatus of the present invention.

FIG. 3 is a perspective view showing a characteristic portion of a second embodiment of the ink jet type image forming apparatus of the present invention.

FIG. 4 is a perspective view showing a characteristic portion of a third embodiment of the ink jet type image forming apparatus of the present invention.

FIG. 5 is a perspective view showing a characteristic portion of a fourth embodiment of the ink jet type image forming apparatus of the present invention.

FIG. 6 is a perspective view showing a characteristic part of a fifth embodiment of the ink jet type image forming apparatus of the present invention.

FIG. 7 is a perspective view showing a characteristic portion of a sixth embodiment of the ink jet type image forming apparatus of the present invention.

[Explanation of symbols]

 Reference Signs List 1 plotter 10 print head 12 carriage 14 base plate 16, 70, 72, 90 tube 18 tube 18a plate 20 flow path member 24, 42, 66, 96 gear group 30, 50 circulating liquid tank 32, 52 circulating liquid heating / cooling device 40 guide Rail 40a Rack 60 Circulating fluid tank 62 Circulating fluid 80 Recovery device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobumori Shimizu 6-3-3, Shimorenjaku, Mitaka City, Tokyo Inside the Copier Corporation (72) Inventor Kenji Nagata 6-3-3, Shimorenjaku, Mitaka City, Tokyo (72) Inventor Hirokazu Ikegami 6-3-3 Shimorenjaku, Mitaka City, Tokyo

Claims (9)

[Claims] A print head having a plurality of ejection nozzles for ejecting ink, and a heating element for ejecting ink from each of the plurality of ejection nozzles disposed in the vicinity of each of the plurality of ejection nozzles; And a carriage that reciprocates in a predetermined direction with the carriage mounted thereon, and an ink jet type image forming apparatus that forms an image on a recording medium by discharging ink from the discharge nozzles while reciprocating the carriage in the predetermined direction. An ink jet type image forming apparatus, comprising: a temperature adjusting unit fixed to a carriage and in contact with the print head for adjusting the temperature of the print head. 2. The temperature adjusting means, wherein a heating medium or a cooling medium is circulated inside the temperature adjusting means, and a medium supply means for supplying the heating medium or the cooling medium to the temperature adjusting means is provided. The inkjet image forming apparatus according to claim 1, wherein: 3. The ink jet image forming apparatus according to claim 2, wherein said medium supply means is mounted on said carriage. 4. The medium supply means is disposed in an area where the carriage reciprocates, and the carriage moves to the medium supply means when the temperature adjustment means is used. The inkjet image forming apparatus according to claim 2, wherein the image forming apparatus is provided. 5. The temperature adjusting means circulates a heating medium or a cooling medium inside the temperature adjusting means, and guides the carriage, in which a rack extending in the predetermined direction is formed, in the predetermined direction. The apparatus according to claim 1, further comprising: a guide rail; and a gear rotatably fixed to the carriage, wherein the gear circulates a heating medium or a cooling medium inside the temperature control means by rotating while meshing with the rack. 5. The inkjet image forming apparatus according to any one of 1 to 4. 6. A heating / cooling means for heating or cooling a heating medium or a cooling medium circulating in the temperature adjusting means is provided in a circulation path. An inkjet image forming apparatus according to claim 1. 7. The print head includes a heat conductive base plate disposed near the heating element and exposed to the outside, and the temperature control unit contacts an exposed portion of the base plate. The inkjet image forming apparatus according to any one of claims 1 to 6, wherein: 8. The apparatus according to claim 2, wherein the medium supply unit or the heating / cooling unit operates or stops based on the temperature of the print head. Inkjet type image forming apparatus. 9. A recovery device for recovering an ink discharge state of the print head by discharging or sucking ink from the print head, wherein the temperature adjusting means controls the ink discharged or sucked by the recovery device. The inkjet image forming apparatus according to any one of claims 1 to 8, wherein the inkjet image forming apparatus is used as a heating medium or a cooling medium.