JPH0444851A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To impart sufficient strength, to carry out heating and fixing at uniform temp. in the lateral direction of a material to be recorded and to prevent the deposition of a waterdrop on the ink emitting surface of a recording head by suppressing that the heat generated by a heat generating means conducts to the region opposed to the recording head of a platen. CONSTITUTION:In arranging a fixed platen 20, the platen part 20A thereof is set so as to come to the position opposed to an ink emitting surface. The platen part 20A is formed by bonding a relatively thick mounting member 21, which is composed of the same material as the fixed platen 20 or a material almost same as that of the fixed platen 20 in heat conductivity, to the main body of the fixed platen 20. Since heat capacity becomes sufficiently large in the platen part 20A by the mounting member 21, the radiation quantity of heat becomes larger than the conduction quantity of heat and the conduction of heat is suppressed. Further, by making the cross-sectional shape of the mounting member 21, constant no density irregularity is generated in both of the platen part 20A and a heater mounting part 20B and the rigidity as the fixed platen is increased.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an inkjet recording device, and in detail,
The present invention relates to an inkjet recording apparatus in which ink recorded on a recording material is fixed by a heater provided on the back side of a member that holds the recording material at a recording position.

[Prior Art] An example of a conventional inkjet recording apparatus of this type is shown in FIG.

Here, 1 is a recording head mounted on a carriage 2, and the carriage 2 is driven by a timing belt stretched between an idler pulley (not shown) and a carriage drive motor (not shown). By reversing the rotation, it is reciprocated along the guide shaft 3. Note that recording head 1
is supplied with ink from an ink cartridge 4 via an ink tube (not shown), and while the carriage 2 is moving from left to right, the ink is supplied from an ink discharge port (not shown) to a recording material, such as a recording sheet 5. Ink is ejected and recording is performed.

6 is a plate-shaped fixed platen that holds the recording sheet 5 at a position facing the ejection surface of the recording head 1 at a predetermined interval; 7 is a feed roller that feeds the recording sheet 5; 8 is in pressure contact with the feed roller rough; A pinch roller 9 is driven to sandwich the recording sheet 5 between them, and 9 is a pinch roller holder for applying pressure to the pinch roller 8. The holder 9 is made of a stainless steel plate or the like, and the spring force of the holder 9 causes the pinch roller to 8 toward the feed roller 7. 10 and 11 hold the recording sheet 5 fed manually, etc., and a feed roller 7 and a pinch roller 8
An upper guide and a lower guide for guiding between.

The upper guide 10 is provided with a guide rail IOA on its upper part, and a leaf spring 2 provided on the lower surface side of the carriage 2.
A is slidably held along this guide rail IOA. (Then, the carriage 2 is moved by the spring force of the leaf spring 2A.
The carriage 2 is urged toward the fixed platen 6, and a part of the carriage 2 is pressed against the sheet holding plate 13 provided in front of the platen 6.
A predetermined distance is maintained between the ink ejection surface IA of the head 1 and the recording sheet 5 by slidably contacting the recording sheet 5. Note that the part of the sheet press plate 13 that a part of the carriage 2 comes into contact with is near the back side of the part of the sheet press plate 13 that the feed roller 7 contacts, and the sheet press plate 13 is moved back by that amount as the recording sheet 5 passes. Then, the carriage 2 similarly moves backward. Therefore, it is possible to maintain the above-mentioned intervals at predetermined intervals regardless of paper thickness and form a high-quality recorded image.

The recording sheet 5 fed by the feed roller 7 and the pinch roller 8 is held by a fixed platen 6 tilted rearward at an angle of approximately 30 degrees, making it easy to see the recording results. In this way, the recorded recording sheet 5 is transferred to the discharge roller 2 and the spur 12B in pressure contact therewith, as shown in FIG.
It is sandwiched between the two and discharged to the stacker section 14. The fixed platen 6 is made of a metal material with good thermal conductivity, such as aluminum, and a heater 15 is fixed to the back side of the fixed platen 6 with an aluminum tape 16 as shown in FIG. For example, set the temperature to 60
By keeping the ink at a temperature of about 80° to 80°, it is possible to avoid drying (it also copes with difficult ink, promotes fixation, and prints).

By the way, in such a fixed platen 6, if the heater 15 is placed on the back side near the position facing the recording head 1, the water contained in the recording sheet 5 itself and the ink will evaporate at the above-mentioned position. There is a possibility that the heater 15 promotes the water droplets to adhere to the ink ejection surface IA of the recording head l. However, when such water droplets are formed, the ink droplet ejected from the ink ejection port may be pulled by the water droplet and its flight path may be bent, or the water droplet may be particularly overlapping the ink ejection port. In this case, ink failure occurs.

Furthermore, there is a risk that the recording sheet 5 may become uneven at the recording position due to the moisture and the rapid heating described above, and the sheet surface may come into contact with the ink ejection surface IA and stain the sheet surface.

In order to eliminate the above-mentioned drawbacks, it is conceivable to provide the heater 15 separately from the fixed platen 5, but it is necessary to install it separately, and in particular, the heater must be arranged so that it acts evenly. However, since the structure is complicated, it is desirable to configure the heater and platen in an integral combination so that their respective functions can be performed independently without being impaired.

Therefore, as shown in FIGS. 5A and 5B, for example,
In the fixed platen 6, slits 17 are provided intermittently between the part C facing the recording head 1 (hereinafter referred to as the platen part) 6A and the part to which the heater 15 is attached (hereinafter referred to as the heater attachment part) 6B. slit 17
Accordingly, proposals have been made to make it difficult for heat to be transmitted from the heater mounting portion 6B to the platen portion 6A.

[Problems to be Solved by the Invention] However, in the fixing device according to the conventional proposal described above, although the separation between the heater mounting portion 6B and the platen portion 6A is temporarily reduced, a seam 6C remains between them. Therefore, it is unavoidable that heat propagates from the heater attachment part 6B to the platen part 6A through these joints 6C, creating a high temperature part in the platen part 6A, where water droplets are generated, and the temperature distribution is affected. This has the drawback that the ink dries slowly and is likely to cause uneven fixation. Furthermore, the formation of the slits 17 results in insufficient strength of the fixed platen 6 itself.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks, to provide a fixed platen with sufficient strength, to be able to perform heat fixing at a uniform temperature in the width direction of a recording material, and to provide a An object of the present invention is to provide an inkjet recording device equipped with a fixing means that can prevent water droplets from being deposited on the ink ejection surface of a head.

[Means for Solving the Problems] In order to achieve the above object, the present invention has a platen that holds a recording material at a position opposite to a recording means, a heat generating means is disposed on the platen, and a heat generating means is disposed on the platen. In an inkjet recording apparatus in which a heat generating means generates heat to fix a recorded image formed on the recording material, the heat generated by the heat generating means is placed in an area of the platen facing the recording head. The present invention is characterized in that it is provided with means for suppressing conduction.

[Function] According to the present invention, the heat conducted from the part of the platen related to the heat generating means to the said part is diffused and dissipated by the heat conduction suppressing means provided in the part of the platen facing the recording head. , the above-mentioned part does not always reach a high temperature, so it is possible to suppress the evaporation of water from the recording material at the position facing the recording head, and prevent water droplets from adhering to the ink ejection surface of the recording head, and preventing water droplets from adhering to the recording surface. It is possible to prevent imperfections that cause unevenness.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail and specifically based on the drawings.

FIGS. 1A and 1B show an example of a fixing device according to the present invention. In these figures, 20 is a fixed platen, 20^ is its platen portion, and 20B is a heater mounting portion. That is, when disposing the fixed platen 20, its platen portion 20A is positioned opposite to the ink ejection surface IA as shown in FIG. In contrast, a relatively thick attachment member 21 made of the same material or a material having substantially the same thermal conductivity is attached by welding or the like.

Note that the temperature of the heater 15 for fixing is generally controlled to a constant temperature using a thermistor or the like, but in this example, if the temperature of the heater mounting portion 20B is controlled in this way, the platen portion 20A has sufficient heat capacity. Since the amount of heat is large, the amount of heat dissipated is greater than the amount of heat conducted, and heat conduction is suppressed. Moreover, by making the cross-sectional shape of the attached member 2 constant, not only will there be no temperature unevenness in either the platen part 20A or the heater handle part 20B, but the rigidity of the fixed platen can be increased. The platen part 20 can contribute
By suppressing the heat conducted to A from the heater attachment portion 20B, the platen portion 20A can function effectively.

Note that in the above example, the attachment member 21 was formed separately from the fixed platen 20 and fixed by welding or the like.
For example, it is suitable for mass production if the platen portion 20A is formed by drawing or the like from a rough material such as aluminum so that the shape of the attachment member 21 is formed integrally with the fixed platen 20.

2A and 2B show a fixing device according to another embodiment of the present invention. In this example, the platen portion 30A of the fixed platen 30 is folded over the heater mounting portion 30B of the platen 30 body. It is formed by folding it thickly, especially by folding the folds toward the recording sheet holding side, that is, the side facing the recording head, as shown in FIG. 2A. In this example, the lower end of the platen 40 is folded three times in an N-shape to prevent heat from being directly transmitted from the heater attachment part 30B side to the sheet holding surface 31. 40A, and by increasing the number of folds in this way, even more heat is transferred to the platen part 40A.
It is possible to suppress the increase due to the transmission of

[Effects of the Invention] As described above, according to the present invention, since a means for suppressing conduction of heat from the fixing heat generating means is provided in the portion of the fixed platen facing the recording head, It is possible to prevent moisture generated by heating from the recording material held on the fixed platen from becoming water droplets and adhering to the ink ejection surface of the recording head. The problem of discharge occurring is resolved. In addition, the above-mentioned portions do not reach high temperatures, which prevents moisture from evaporating from the recording material at the position facing the recording head, and at the same time prevents the recording head from drying out.

Furthermore, by making the portion of the fixed platen facing the recording head evenly thicker than the heater mounting portion to suppress heat conduction, the rigidity of the fixed platen itself can be increased, reducing the possibility of bending. It is possible to provide an inkjet recording apparatus that suppresses vibrations and vibrations and is suitable even when handling a recording material with a wide sheet width.

[Brief explanation of the drawing]

FIG. 1A is a perspective view showing an example of the configuration of a fixed platen according to the present invention, FIG. 1B is a sectional view of FIG. 1A, and FIGS. FIG. 3 is a perspective view showing the configuration of a conventional inkjet recording device, FIG. 4 is an explanatory diagram of the configuration near the fixed platen of the recording device shown in FIG. 3, and FIG. 5A and 5B are a perspective view and a sectional view, respectively, showing the structure of the fixed platen shown in FIG. 4. DESCRIPTION OF SYMBOLS 1... Recording head, LA... Ink ejection surface, 2... Carriage, 5... Recording sheet, 15-... Heater, 20, 30.40... Fixed platen, 20A, 30
A, 40A... platen section, 20B, 30B,
40B... Heater attachment part, 21... Attachment member, 31... Seat holding surface. $, November 1, 1, 1, fixed platen that has the power to invent ゛ρ゛
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Claims (1)

[Scope of Claims] 1) A platen is provided for holding a recording material at a position opposite to a recording means, a heat generating means is disposed on the platen, and the heat generating means is heated to generate heat on the recording material. In an inkjet recording apparatus that fixes a formed recorded image, a means for suppressing conduction of heat generated by the heat generating means is provided in an area of the platen facing the recording head. An inkjet recording device featuring: 2) The means for suppressing conduction of heat from the heat generating means is formed as a thick portion that is thicker than the thickness of a region of the platen in which the heat generating means is disposed. inkjet recording device. 3) The recording means includes an electrothermal converter for ejecting ink to form an image on the recording material, and generates foam in the ink using the heat generated by the electrothermal converter, 2. The inkjet recording apparatus according to claim 1, wherein ink is ejected in accordance with pressure changes caused by the bubbling.