JPH03213352A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To improve heat transfer by forming a first heat exchange section for effecting heat exchange with a recording head into a flat shape and forming the cross section of a second heat exchange section, extending from the first section, for effecting heat exchange with heat medium liquid in a container into a circular-pipe shape. CONSTITUTION:Heat pipes 2A-2D are disposed in juxtaposition with recording heads 11A-11D respectively, while ink having different colors is delivered from each head onto a recording material 7 which is moved in a direction normal to the arrangement direction of the heads 11A-11D to effect recording. A heat radiating section 9 having protruding strips for radiating heat is providing on one surface of a heat medium container 8 charged with liquid of heat medium for effecting heat exchange with the pipes 2A-2D and a fan 10 is provided on the lower side of the section 9 to cool the heat medium filled in the container 8 through the section 9. In this manner, heat exchange of high efficiency is achieved, whereby the temperature of each of the heads is equalized and controlled stably to predetermined temperature, while the device as a whole can be made smaller.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an inkjet recording device.

[Prior Art] Conventionally, among recording apparatuses, an inkjet recording method in which information such as characters and images is recorded by ejecting a recording liquid from a recording head is widely known.

This type of recording device has the advantage that it has particularly low operating noise compared to other recording methods, has a simple and inexpensive basic mechanical structure, and can be easily converted to color. Inkjet recording apparatuses using line-type recording heads have recently been devised in order to achieve even higher speeds.

In the inkjet recording method, the ejection conditions change depending on the temperature at which the head is maintained, so it is necessary to control the temperature at a constant level.
In particular, in line-type recording heads for bubble-jet inkjet recording that utilize phase changes in the recording liquid caused by thermal energy, it is necessary to prevent positional and temporal temperature fluctuations in the head even when the recording head is locally driven. Temperature control is required to equalize the temperature.

The present inventors first installed a heat vibrator 2 on a line-type recording head 1 as shown in FIG. The heating means 3 and forced heat radiation means 4 are controlled by a controller 6 based on the output of a temperature sensor 5 disposed at an appropriate position in the recording head 1, so that positional and temporal temperature changes do not occur in the recording head 1. We have confirmed that the temperature can be controlled reliably.

[Problems to be Solved by the Invention] However, when a plurality of line type recording heads are provided as in color recording, each head is driven individually, so it is necessary to control each recording head using the above idea. control becomes complicated.

Therefore, as shown in FIG. 4, a plurality of recording heads IA,
Heatvibe 2A, 2B for IB, Ic and ID
, 2C and 2D, respectively, and then guiding them to a common forced heat radiating means 4, disposing heat radiating fins 41 on the forced heat radiating means 4, and cooling them with a common fan 42. However, in this case, since heat is exchanged between the recording heads, there is a problem that when the entire recording head is cooled, the temperature of the recording heads other than the desired one decreases, resulting in blurred recording.

An object of the present invention is to provide a compact temperature control means that can efficiently equalize and control the temperature of a plurality of recording heads, and that can be downsized. An object of the present invention is to provide a color inkjet recording device that can improve registration accuracy.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an inkjet recording apparatus that performs recording by ejecting ink from a recording head onto a recording material, in which the recording head is provided with a a first heat exchange section having a flat cross-sectional shape that maintains contact with the recording head and exchanges heat with the recording head; and an area extending from a region of the first heat exchange section that exchanges heat between the recording head and is,
a heat exchange member that is inserted into a container and has a second heat exchange portion having a circular cross-sectional shape that exchanges heat with the heat medium liquid in the container; and a heat exchange member that controls the temperature of the heat medium liquid. The invention is characterized by comprising a control means.

[For production]

According to the present invention, since the first heat exchange part of the heat exchange member has a flat cross-sectional shape and maintains contact along the longitudinal direction of the recording head, efficient heat exchange (heat exchange) is achieved between the first heat exchange part and the recording head. is carried out, and the heat carried through the first heat exchange section is efficiently exchanged between the second heat exchange section having a circular cross-sectional shape and the heat medium liquid in the container. By controlling the temperature of the heat medium liquid by a set of temperature control means including a heating means and a cooling means, it is possible to not only maintain the temperature in a plurality of recording heads evenly, but also to 1
It is possible to maintain a narrow interval between each recording head unit including the heat exchanger, and it is possible to improve registration accuracy and facilitate alignment.

〔Example〕

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

FIG. 1 shows an embodiment of the invention. Here, 11A,
For example, IIB, IIC, and 110 are recording heads for black, cyan, magenta, and yellow, and each recording head is constructed as shown in FIG. That is, these recording rods 11 are constructed on a substrate member 12, and a plurality of ink ejection ports 13 are arranged in a line on the surface of the recording rod 11 facing the recording material. A liquid path (not shown) communicates with the ejection port, and each liquid path is further provided with an electric/thermal conversion element that selectively generates thermal energy in accordance with a recording signal. Further, ink is supplied to each liquid path from a common liquid chamber (not shown). A support member 14 is attached to the substrate member 12 and supports the recording head 11. Furthermore, ink is supplied to the common liquid chamber of the recording rad 11 from an ink reservoir (not shown) provided separately from the recording rad 11.

Recording heads IIA and JIB configured as described above.

As shown in FIG. 1, heat vibes 2A, 2B, 2C, and 2D are attached to heat vibrators 2A, 2B, 2C, and 2D, respectively, as shown in FIG. Ink of different colors is ejected from each recording head onto the recording material 7 to perform recording. Reference numeral 8 denotes a liquid medium container filled with a heat medium liquid in which heat is exchanged between the heat vibrators 2A to 2D. A heat dissipation section 9 is provided, and a blower fan 10 for cooling the heat medium liquid filled in the liquid medium container 8 via the heat dissipation section 9 is disposed on the lower surface side of the heat dissipation section 9. It is.

Each of the heat vibrators 2A to 2D is formed flat to be easily installed along the recording heads IIA to 110 and to facilitate heat transfer, and one end thereof is formed into a circular tube shape and can be folded. It is bent and inserted into the liquid medium container 8. Reference numerals 20A to 20D are extension portions each formed into a circular tube shape, and a seal 15 for keeping the container 8 liquid-tight is provided at a portion thereof penetrating the container 8.

By forming the heat vibrators 2A to 2D and their extension parts 20A to 200 in this manner, highly efficient heat exchange can be performed, and the temperature of each head can be equalized and stably controlled to a predetermined temperature. In addition, since the interval between recording heads can be narrowed, registration accuracy can be improved, and the entire apparatus can be made smaller. 16 is a heater for heating the liquid heat medium, and 17 is used to stir the liquid medium in the container 8 to make the liquid temperature uniform, and to obtain efficient heat exchange with the heat vibrators 2A to 2D. Stirrer for making
7A is the stirring impeller, and 17B is the stirring motor.

The temperature of the IA medium liquid in the liquid medium container 8 is detected by a temperature sensor 18, and the detection signal is input to the controller 19, so that the controller 19 controls the heater 16 and the air blower to keep the liquid temperature constant. Controls on/off of the fan 10.

As described above, according to this embodiment, a plurality of heat vibrators 2A to 2D are connected to each other through one container 8 containing liquid as a heat medium.
This not only makes it possible to control the temperature of the recording heads 1A to 1D by uniformly heating or cooling the recording heads to average the temperature during that time (it is possible to average the temperature of each recording head). For example, even if only one recording head LA performs recording and the other recording heads IB, IC, and ID do not perform recording, the heat generated by the recording head IA will indirectly transfer to the other recording heads IB~ The temperature is then transmitted to the ID, allowing each print head to maintain an appropriate temperature for printing with efficient power usage.

Furthermore, when color recording is performed, normally three colors are not ejected at the same time.

This is because, in general, when using three colors, OCR (under
This is because the ink is replaced with black ink as part of the color removal process. Therefore, when setting the power used for heat radiation, the number of recording heads used can be limited to three or less, and it is unnecessary to provide a high-output heat radiation means.

Note that each of the recording heads IIA to 110 is provided with the heat vibrator 2A to 2D in an integrated manner, and by forming a unit, attachment to the liquid medium container 8 is facilitated. By using the material, it is possible to easily adjust the position of the recording head IIA-110.

Now, the smaller the interval between adjacent heads of the recording head IIA-11D, the more preferable it is in order to improve the precision of recording positioning, that is, registration, and to further downsize the entire apparatus. Therefore, it is desirable that the thickness of the heat vibes 2A to 2D, which are provided so as to maintain contact with each of the recording heads IIA to IID in the recording area, be as thin as possible without adversely affecting the flow of the heat medium. It will be done.

On the other hand, considering the maximum amount of heat dissipated by each of the recording heads IIA to LID, it goes without saying that it is necessary to use a heat vibrator having a corresponding amount of heat transport. The present invention shows that the efficiency of heat exchange with the heat medium is improved by making the vibrator into a round shape, that is, a cylindrical shape, rather than making it flat in the extension parts 20A to 200 that exchange heat with the heat medium. The person has confirmed.

Therefore, as a preferred example, in the case of a 400 dpi A3 full line type recording head, the thickness of the short side of the heat vibrators 2A to 2D, that is, the thickness in the arrangement direction is dl.
, 5≦d, where d is the interval between each recording head IIA-11D, and d3 is the distance between the side surface of the heat vibe between adjacent heads and the side surface of the opposite recording head.
≦20mm, 5≦d1≦20mm, 056361
5 mm, however, it is set to satisfy the condition of d>d, and on the other hand, the diameter of the heat vib extension parts 20A to 20D is set to be IO≦D≦3, which is a preferable diameter that is efficient in terms of heat exchange characteristics.
Furthermore, by setting the thickness in the range of 0+nm, the present invention brings about excellent effects particularly in bubble jet recording heads and recording apparatuses among ink jet recording systems.

This is because such a system can achieve higher recording density and higher definition.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,7407g6. 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, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. The electrothermal converter that is
By applying a single drive signal that corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling, the electrothermal transducer generates thermal energy, causing film boiling on the heat-active surface of the recording head. As a result, bubbles in the liquid (ink) can be formed in a one-to-one correspondence with this drive signal, which is effective, and the liquid (ink) is ejected to form at least one drop. It is more preferable to use a pulse-shaped drive signal as the bubble growth and contraction occurs immediately and appropriately, making it possible to eject liquid (ink) with particularly excellent responsiveness. Specification No. 4463359, No. 4345
262 is suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

The configuration of the recording head includes, in addition to the combination configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the wafer is placed in a bending region. In addition, Japanese Patent Application Laid-Open No. 1989-5 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
No. 9-123670 and Japanese Patent Application Laid-Open No. 59/1989 which discloses a configuration in which a discharge portion is made to correspond to an opening that absorbs pressure waves of thermal energy.
The effects of the present invention are also effective even if the structure is based on the publication No.-138461. In other words, regardless of the form of the recording head, recording can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by a recording apparatus.

Such a recording head may have either a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration in which a single recording head is formed in one direction. In addition, even the serial type shown above can be installed on the main body of the device, allowing for electrical connection to the main body of the device and supply of ink from the main body of the device.Replaceable chip type recording heads. Alternatively, the present invention is also effective when using a cartridge type recording head that is integrally provided with the recording head itself.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention, because the effects of the present invention can be further stabilized. Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing.

In addition, regarding the type and number of recording heads installed, for example, in addition to one type that corresponds to single-color ink, there is also a plurality of recording heads that correspond to multiple inks with different recording colors and densities. It may be something that can be done.

In addition, in addition to being used as an image output terminal for information processing equipment such as a computer, the inkjet recording apparatus of the present invention may also take the form of a copying machine combined with a league, etc., or a facsimile machine having a transmission/reception function. It may be something.

[Effects of the Invention] As described above, according to the present invention, the first heat exchange section that transfers heat to and from the recording head has a flat shape, and the first heat exchange section extends from the first heat exchange section. By making the cross-sectional shape of the second heat exchange part that exchanges heat with the heat medium liquid in the container into a circular tubular shape, the heat transfer efficiency can be improved, especially in an inkjet having a plurality of inkjet recording heads. When applied to a recording device, it becomes possible to uniformly control the temperature of multiple recording heads using a set of control means including a heating means and a cooling means, thereby increasing the efficiency of power usage.
In particular, less power is required for cooling, the heat dissipation means can be small, and this contributes to making the entire recording device more compact and reducing costs.

In addition, by flattening the first heat exchanger, it is possible to reduce the distance between the recording heads arranged in parallel, thereby improving the accuracy of registration and facilitating registration. In addition, by bending the cross-sectional shape of the second heat exchange part into a circular tube shape and inserting it from above the container, for example, it is possible to prevent the heat medium liquid from leaking from the insertion port, and also to prevent the heat exchange member and the recorder from leaking. Each head unit consisting of a head can be easily replaced.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention, FIG. 2 is a perspective view showing one of the recording heads according to the present invention, and FIGS. 3 and 4 are conventional monochrome and color recording heads. FIG. 3 is a perspective view showing the configuration of an inkjet recording head and its temperature control means. 2A to 2D...Heat vibrator, 7...Recording material, 8...Liquid medium container, 9...Heat radiation section, 10...Blower fan, 11, IIA to 110...Recording spatula 16 . . . Heater, 18. Temperature sensor, 19. Controller, 20A to 20D. Extension portion.

Claims (1)

[Scope of Claims] 1) In an inkjet recording apparatus that performs recording by ejecting ink from a recording head onto a recording material, the recording head maintains contact along the longitudinal direction and exchanges heat with the recording head. A first heat exchange section having a flat cross-sectional shape extending from a region where heat exchange is performed between the recording head of the first heat exchange section and inserted into a container, A heat exchange member having a second heat exchange portion having a circular cross-sectional shape for exchanging heat with a heat medium liquid, and a control means for controlling the temperature of the heat medium liquid. Inkjet recording device. 2) A plurality of the recording heads are arranged substantially horizontally in parallel, each of which is provided with the heat exchange member, and the second heat exchange part is bent downward from the first heat exchange part to be inserted into the container. 2. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is inserted into each of the inkjet recording apparatuses. 3) The control means includes a heating means for heating the heat medium liquid, a cooling means for cooling the heat medium liquid, a detection means for detecting the temperature of the heat medium liquid, and a temperature detected by the detection means, the heating means or and a drive control means for controlling the drive of the cooling means.
or 2. The inkjet recording device according to 2. 4) The recording head is equipped with a thermal energy generating element as an ejection energy generator that generates thermal energy used to eject ink, and utilizes rapid pressure changes caused by bubbles generated by the thermal energy. 4. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus discharges the ink by discharging the ink. 5) The inkjet recording apparatus according to claim 1, wherein the recording head is provided with the ejection ports over the entire width of the recording material.