JPH05318716A - Fixing mechanism for ink jet recorder - Google Patents

Abstract

PURPOSE:To reduce irregularity in density caused by a wrinkle or the like of a material to be recorded by improving thermal efficiency. CONSTITUTION:Recording paper 1 being a medium to be recorded is carried in the arrow A direction in the figure respectively with a pair of a paper feed roller 3 and a paper delivery roller 4. A recording head 2 is so arranged that recording is carried out downwards. A halogen lamp heater 6 is provided as a heating source for heating a rear surface of the recording paper 1. Intensive infrared rays radiated from the halogen lamp heater 6 are absorbed in an absorption coating applied to an inner surface of a heating cylinder 7 heated by a dirving means, and converted to heat. A heat conducting component 8 made from soft spongy silicone rubber of a good thermal conductivity is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing mechanism of an ink jet recording apparatus which ejects ink to form an image on a recording medium.

[0002]

2. Description of the Related Art Conventionally, a fixing mechanism of an ink jet recording apparatus is provided with a heater and a heat transfer plate or a heating cylinder for transmitting the heat to the recording medium on the back side of the recording medium (the side opposite to the printing surface). A configuration has been widely used in which a recording medium is heated by heating and the ink on the recording medium is evaporated and dried.

[0003]

However, in the above-mentioned conventional example, since there is unfixed ink on the printing surface side of the recording medium, it is possible to completely bring the recording medium into close contact with the heater by a roller or the like. It was not possible to avoid the decrease in thermal efficiency due to some floating. Therefore, in order to compensate for this, it is necessary to provide a high-temperature and large-sized heater or to provide a long heating path in order to obtain a longer heat transfer time. In addition, the wrinkles of the recording medium, and the difference in the drying speed between the portion with the floating and the portion without the floating may change the degree of ink penetration into the recording medium, resulting in uneven density that deteriorates the image.

It is an object of the present invention to provide a fixing mechanism of an ink jet recording apparatus which can improve thermal efficiency and reduce uneven density due to wrinkles of a recording member.

[0005]

A fixing mechanism of an ink jet recording apparatus according to the present invention comprises an ink jet recording head for ejecting ink from an ejection port toward a recording medium to perform recording, and a conveyance for conveying the recording medium. In a fixing mechanism of an inkjet recording apparatus having a heating member that contacts a back surface of a recording surface of the recording medium on which recording is performed by the inkjet recording head, a portion of the heating member that contacts the recording medium. It is characterized in that a flexible heat transfer member is provided.

The flexible heat transfer member may comprise a sponge-like member or a felt-like member.

[0007]

According to the present invention, the flexible heat transfer member is provided in the portion of the heating member that comes into contact with the recording medium, whereby the clearance between the back surface of the recording medium and the heat transfer member is eliminated, and thermal efficiency is improved. , So that uniform heating can be obtained.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a fixing mechanism of an ink jet recording apparatus of the present invention.

A recording paper 1 which is a recording medium has a pair of paper feed rollers 3 each driven by a driving means (not shown).
Also, the sheet is conveyed in the direction of arrow A in the figure by the sheet discharge roller 4. The ink jet recording head 2 of the ink jet recording apparatus is a so-called full line type recording head in which ejection nozzles are arranged over the entire paper width, and in this embodiment, the ink jet recording head 2 is arranged so that recording is performed downward.

The image recorded on the recording paper 1 by the ink jet recording head 2 is destroyed by the discharge roller 4 before the ink is fixed on the recording paper 1, so that the image is destroyed and the roller is soiled. It is necessary to fix it quickly. Therefore, in this embodiment, a method of heating the back surface of the recording paper 1 to about 150 ° C. to dry and fix the ink is adopted, and the halogen lamp heater 6 is provided as a heating source therefor. The strong infrared rays radiated from the halogen lamp heater 6 are absorbed by the absorbing paint applied to the inner surface of the heating cylinder 7 which is heated by the driving means (not shown) and converted into heat. Conventionally, this heat is transferred by directly applying the outer peripheral portion of the heating cylinder 7 to the back surface of the recording paper 1,
Although the recording paper 1 was heated, in this embodiment, the recording paper 1 swells due to the water content of the ink and wrinkles are formed, so that a gap is generated between the recording paper 1 and the heating cylinder 7, and the heat conduction is partially deteriorated. In order to prevent the disadvantage that the fixing speed decreases,
A heat transfer member 8 made of flexible sponge-like silicon rubber having a high thermal conductivity is provided, and the heat transfer member 8 is devised so that the heat is surely transferred even if there is some unevenness on the back side of the recording paper 1.

Therefore, heating unevenness is reduced and printing density unevenness (a phenomenon in which a dot diameter in a portion where the fixing speed is fast and a dot diameter becomes large due to bleeding in a portion where the fixing speed is fast) resulting from the heating unevenness is small and thermal efficiency is good. An inkjet recording device can be obtained.

In this embodiment, sponge-like silicone rubber is used as the heat transfer member, but any material having good thermal conductivity, flexibility and heat resistance of 150 ° C. or higher can be used in the same manner. For example, a stainless fiber made of felt or a brush of bristles may be used.
Further, in this embodiment, the heat transfer member is formed in a roller shape, but it may be formed in a belt shape or a flat plate shape to obtain the same effect.

FIG. 2 is a schematic configuration diagram showing the configuration of the ink jet recording head used in this embodiment.

The ink jet recording head 2 includes a substrate 201 made of silicon or the like, a plurality of electrothermal converting elements 202 which are thermal energy generating elements for generating thermal energy for ejecting ink, and an electrothermal converting element 202.
A plurality of nozzle walls 203 for separating the above and a top plate 204 provided so as to face the substrate 201 with the nozzle walls 203 interposed therebetween. The energy of foaming generated by heating the ink is used to eject ink droplets from the plurality of ejection ports 208. The ink is supplied to the common liquid chamber 207 from an ink tank (not shown) via a supply pipe 205 and a connector 206,
It is supplied to the nozzle (each space surrounded by the substrate 201, the nozzle wall 203, and the top plate 204) by a capillary phenomenon.

The present invention is particularly effective in an ink jet recording head and an ink jet recording apparatus of the ink jet recording method of ejecting ink with thermal energy proposed by Canon Inc.

Regarding the typical structure and principle thereof, for example, US Pat. Nos. 4,723,129 and 4,740 are incorporated.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, a liquid (ink) is used.
By applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or liquid path holding the , Heat energy is generated in the electrothermal converter, and the film is boiled on the heat acting surface of the recording head,
As a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal, which is effective. The growth of this bubble,
The contraction causes the liquid (ink) to be ejected through the ejection opening to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. This pulse-shaped drive signal is disclosed in U.S. Pat.
Those as described in 345262 are suitable. If the conditions described in US Pat. No. 4,313,244 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, other than the combination constitution (straight liquid flow passage or right-angled liquid flow passage) of the ejection port, the liquid passage, and the electrothermal converter as disclosed in the above-mentioned specifications. U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4, which disclose a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of 459600 is also effective for the present invention. In addition, Japanese Patent Application Laid-Open No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration corresponding to the ejection portion.

Further, as a full line type recording head having a length corresponding to the width of the maximum recording medium which can be recorded by the ink jet recording apparatus, a combination of a plurality of recording heads as disclosed in the above-mentioned specification is used. The present invention can exert the above-mentioned effects more effectively, although either the constitution satisfying the length or the constitution as one recording head integrally formed may be used.

In addition, by being attached to the apparatus main body, it can be electrically connected to the apparatus main body and can be supplied with ink from the apparatus main body by a replaceable chip type recording head, or the recording head itself. The present invention is also effective when a cartridge-type recording head that is specially provided is used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a constitution of the ink jet recording apparatus, because the effect of the present invention can be further stabilized. Specific examples thereof include capping means, cleaning means, pressurizing or suctioning means, electrothermal converter or a heating element other than this, or preheating for the recording head. It is also effective to perform stable recording by performing a preliminary discharge mode in which discharge is performed separately from the means and the recording.

Further, the recording mode of the ink jet recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrally formed or a plurality of combinations may be used. The present invention is extremely effective for an apparatus provided with at least one of color or full color by color mixture.

In the embodiment of the present invention described above, the ink is described as a liquid, but it is an ink that solidifies at room temperature or below, and is softened or liquid at room temperature, or the ink itself is 30 in the above ink jet. Generally, the temperature is adjusted within the range of ℃ or more and 70 ° C. or less to control the temperature of the ink so that the viscosity of the ink is within the stable ejection range. good. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy for the state change of the ink from the solid state to the liquid state, or
By using ink that solidifies when left standing for the purpose of preventing evaporation of the ink, the ink is liquefied by applying heat energy according to the recording signal and reaches the recording medium or the one that is ejected as an ink liquid. It is also applicable to the present invention to use an ink which has a property of being liquefied only by thermal energy, such as one which has already started to solidify at this point. In such a case, the ink is disclosed in JP-A-54-568.
47 or JP-A-60-71260, a mode in which it is opposed to the electrothermal converter in the state of being held as a liquid or solid in the recesses or through holes of the porous sheet. Also good. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

[0024]

As described above, according to the present invention, a flexible heat transfer member having good thermal conductivity is provided in a portion of a heating member that heats the back surface of the recording medium to dry and fix the ink and is in contact with the recording medium. By providing it, it becomes possible to reduce density unevenness due to wrinkles of the recording medium. Further, since the loss of heat conduction due to the gap between the recording medium and the heating body is reduced, the thermal efficiency is improved, the amount of heat supplied from the heater can be reduced, and the power consumption of the entire apparatus can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a configuration of an inkjet recording head used in this embodiment.

[Explanation of symbols]

 1 Recording Paper 2 Inkjet Recording Head 3 Paper Feed Roller 4 Paper Ejection Roller 6 Halogen Lamp Heater 7 Heating Cylinder 8 Heat Transfer Member

Claims (3)

[Claims] 1. An inkjet recording head for recording by ejecting ink from a discharge port toward a recording medium, a conveying means for conveying the recording medium, and the recording medium on which recording is performed by the inkjet recording head. In a fixing mechanism of an inkjet recording apparatus having a heating member that abuts on the back side of a recording surface of a recording medium, a flexible heat transfer member is provided in a portion of the heating member that contacts the recording medium. The fixing mechanism of the device. 2. The fixing mechanism for an ink jet recording apparatus according to claim 1, wherein the flexible heat transfer member is a sponge-like member. 3. The fixing mechanism for an ink jet recording apparatus according to claim 1, wherein the flexible heat transfer member comprises a felt-like member.