1. Field of the Invention
The present invention relates to an ink jet recording apparatus, an ink cartridge and an ink jet head unit, and more particularly to an ink jet recording apparatus, an ink cartridge and an ink jet head unit, which are capable of high quality color recording with good water resistance and no spreading of ink.
The term xe2x80x9crecordingxe2x80x9d includes application of ink to (or printing of) all kinds of ink supporting body such as cloth, threads, paper and sheet materials. This invention can be applied to any kind of equipment that use such recording materials as paper, cloth, nonwoven cloth and OHP sheets for over-head projector. Among equipment to which the invention is applicable are office equipment such as printers, copying machines and facsimiles, and also mass production equipment.
2. Description of the Prior Art/Related Art
The ink jet recording method involves ejecting small droplets of recording liquid and landing them on a recording material such as paper (hereinafter referred to as a recording medium) to record information.
This recording method, because of its advantages such as low noise, low running cost, small size of apparatus and ease with which color printing is implemented, has found wide use in printers and copying machines.
This kind of ink jet recording generally employs ink whose major component is water that contains water-soluble, high boiling point solvent, such as glycol, for the purpose of preventing drying and clogging. Recording the ordinary paper using such ink, however, may result in poor fixing of ink on the paper or non uniform image presumably due to uneven distribution of loading materials and sizes applied to the surface of the paper. When a color image is formed, in particular, ink droplets of two or more different colors are successively ejected overlapping the previous ones before the droplets that have landed become fixed to the recording medium, so that colors may get blurred at boundary portions in the image between different colors or mixed unevenly causing feathering. As a result, a satisfactory printed image may not be obtained.
To solve the above-mentioned problem, a method has been proposed which involves purchasing a particular recording medium applied over its entire surface to a specified thickness with a substance that fixes a dye in the recording liquid and ejecting the recording liquid against the recording medium.
With such a method, however, satisfactory recording cannot be realized unless the above-mentioned special recording mediums are purchased.
Another method is known which sprays a colorless treatment liquid, that renders the dye in the recording liquid insoluble, over a wide area on one surface of the recording medium irrespective of the positions where the recording liquid droplets are landed.
Because the treatment liquid is also applied to portions not related to ink ejection, the amount of the treatment liquid is far greater than the amount of ink used, increasing the running cost and the size of the apparatus.
A first object of this invention is to provide an ink jet recording apparatus as well as an ink cartridge and an ink jet head unit mountable on the apparatus, which can solve the above-mentioned conventional problems, can perform water-resistant, anti-bleed processing on a recorded image swiftly and accurately with a minimum amount of processing liquid, and can perform this processing without requiring a recording head of special construction for ejecting the processing liquid.
A second object of this invention is to provide an ink jet recording apparatus as well as an ink cartridge and an ink jet head unit mountable on the apparatus, which can realize, without degrading operability, high-quality, high-reliability image recording that exhibits improved water resistance for ordinary paper and produces no feathering or color bleed at the boundaries between different colors in color recording.
In order to achieve these objects, in a first aspect of the present invention, a recording apparatus, which performs recording on a recording medium by using a coloring material-containing ink accommodated in a first accommodating portion and processing liquid accommodated in a second accommodating portion to make insoluble or coagulate the coloring material in the ink, comprises:
a means to hold a first ink jet head for ejecting the ink and a second ink jet head for ejecting the processing liquid in line with each other and opposite the recording surface of the recording medium; and
a control means to control the ejecting of the processing liquid from the second ink jet head in connection with the ejecting of the ink from the first ink jet head.
Here, the first ink jet head and the second ink jet head may be arranged in the order of the second ink jet head and the first ink jet head in the direction in which these two heads perform at least the image recording so that the processing liquid can be ejected from the second ink jet head prior to the ejecting of the ink from the first ink jet head.
The first ink jet head and the second ink jet head may be combined together to form an ink jet head unit.
The ink jet head unit may be removably mounted on a carriage that reciprocally moves in a direction in which the unit moves when performing the image recording.
The ink jet head unit mounted on the carriage may be removably provided with the first accommodating portion that accommodates the ink containing the coloring material and with the second accommodating portion that accommodates the processing liquid to make insoluble or coagulate the coloring material in the ink.
It may further comprise a processing liquid supply means to supply the processing liquid to the second accommodating portion.
The processing liquid supply means may be removably fixed on a guide along which the carriage reciprocally moves and, only when the carriage moves to a predetermined position, is connected to the second accommodating portion to supply the processing liquid thereto.
The processing liquid supply means may further include a pressurizing pump that uses a driving force of the carriage to supply the processing liquid to the second accommodating portion.
The pressurizing pump may include bellows that pressurizes the interior of the processing liquid supply means when the second accommodating portion is connected to the processing liquid supply means.
The processing liquid supply means may include a soaking body that retains waste liquid of the processing liquid or the ink.
The first ink jet head may have an electro-thermal conversion body as an element that generates thermal energy for ejecting the ink.
In order to achieve these objects, in a second aspect of this invention, an ink jet head unit, comprises:
a first ink jet head to eject a coloring material-containing ink; and
a second ink jet head to eject processing liquid to make insoluble or coagulate the coloring material in the ink;
wherein the first ink jet head and the second ink jet head are integrally combined.
Here, the second ink jet head and the first ink jet head may be arranged in this order in a direction in which the both heads move when performing at least image recording.
In order to achieve these objects, in a third aspect of this invention, an ink cartridge, comprises:
a first accommodating portion that is removably fixed to a first ink jet head which ejects a coloring material-containing ink, the first accommodating portion accommodating the ink to be supplied to the first ink jet head.
Here, the first accommodating portion may be divided into a first portion containing a absorbing body that absorbs and retains the ink and a second portion that accommodates the ink and communicates with the first portion through small holes.
The first accommodating portion may be divided according to the kind of the coloring material in the ink.
The first accommodating portion may be divided as claimed in the density of the ink.
In order to achieve these objects, in a fourth aspect of this invention, an ink cartridge, comprises:
a second accommodating portion that is removably fixed to a second ink jet head which ejects processing liquid to make insoluble or coagulate a coloring material contained in ink, the second accommodating portion accommodating the processing liquid to be supplied to the second ink jet head.
Here, a surface tension of the processing liquid may be smaller than the surface tension of the ink.
In order to achieve these objects, in a fifth aspect of this invention, an ink cartridge, comprises:
a first accommodating portion that accommodates ink to be supplied to a first ink jet head which ejects a coloring material-containing ink; and
a second accommodating portion that accommodates processing liquid to be supplied to a second ink jet head which ejects the processing liquid to make insoluble or coagulate the coloring material in the ink;
wherein the first accommodating portion and the second accommodating portion are integrally combined.
The ink may contain anionic dye.
The ink may contain at least anionic compound and pigment.
The processing liquid may contain a cation substance including a low-molecular component and a high-molecular component.
With this invention, because the recording head is so arranged as to allow the processing liquid to be sprayed prior to the ejecting of ink onto the recording medium, it is possible to apply a sufficient amount of processing liquid for recording to the recording medium. According to the recording data, the processing liquid is sprayed over only the locations on the recording medium where the ink is to be ejected, so that the ink lands on the applied processing liquid. This makes it possible to form a desired stable image by using only the minimum required amount of processing liquid, thereby optimizing the amount of processing liquid applied prior to the ink ejecting and lowering the running cost and the manufacture cost of the apparatus.
Further, because the recording heads of the same construction and configuration are employed, there is no need to change the design of the recording head according to whether the droplets to eject are the processing liquid or the ink, thus improving the development efficiency and productivity.
Moreover, the recording head for ejecting the ink containing a coloring material and the recording head for ejecting the processing liquid for coagulating the coloring material in the ink may be integrally held by a frame, or the nozzle for the ink containing the coloring material and the nozzle for the processing liquid that coagulates the coloring material in the ink may be provided in the same recording head. This construction makes it possible to eject the processing liquid and the ink immediately following it in each line during each scan of the recording heads. This in turn allows the original purpose of the processing liquid to be accomplished even when the image data transfer from the host computer is halted.
Furthermore, the recording heads for ejecting the processing liquid may be arranged on both sides of the recording head for ejecting the ink. This construction makes it possible to apply the processing liquid to the recording medium even during the bi-directional scan of the carriage, which in turn allows the output time to be reduced by the bi-directional recording and the recording speed to be improved.
In the ink jet recording apparatus of this invention, the colorless or light-colored transparent liquid (referred to as a processing liquid) containing a compound to render dye in the ink insoluble is sprayed onto the recording medium according to the image information, followed by ink of one color or two or more colors being ejected against the recording medium according to the image information. The apparatus has a dedicated tank for the processing liquid whose capacity is equal to or greater than that of the colored ink tank and which is installed in the apparatus body. The apparatus is so constructed as to make easily recognizable to an operator the necessity for replacing the tank of the processing liquid. High reliability of the recording apparatus is thus realized.
These and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.