Liquid droplet discharging method, and liquid droplet discharging apparatus

This application is a divisional application of U.S. Ser. No. 11/274,767 filed Nov. 15, 2005, which is a continuation application of U.S. Ser. No. 10/844,972 filed May 13, 2004, now U.S. Pat. No. 6,992,746 issued Jan. 31, 2006 which claims priority to Japanese Patent Application No. 2003-135791 filed May 14, 2003. The entire disclosures of each of the above applications are incorporated herein by reference.

1. Field of the Invention

The present invention relates to a liquid droplet discharging method and to a liquid droplet discharging apparatus.

2. Description of Related Art

In recent years, liquid crystal devices, electroluminescence devices and the like have been used for the display unit of electronic equipment such as mobile telephones and portable computers. For example, in a liquid crystal device, a color filter is formed by arranging dot-shaped filter elements of the respective colors of red, green, and blue in a predetermined pattern such as a stripe pattern, a delta pattern, or a mosaic pattern on a surface of a substrate formed from glass, plastic or the like.

A method of forming this type of color filter is known in which, while a dye droplet discharging head, which discharges liquid droplets of red, green, and blue dyes is being scanned, liquid droplets are discharged onto an acrylic resin that has been coated onto a glass substrate, so as to adhere thereto (for example, see Japanese Unexamined Patent Application, First Publication No. H02-173703).

Note that, because it is necessary for the respective liquid droplets to be adhered to positions on the substrate that are determined in advance, when a large number of color filters are being formed on a substrate having a large surface area, a mechanism that can precisely adjust the positions of the substrates has been required. In particular, in the case of a color filter that is formed in a minute pattern on a substrate, or in the case of a circuit having a complex pattern or the like, it is necessary to provide an adjustment mechanism having a high degree of precision. Furthermore, if time is needed in order to drive the mechanism for adjusting the position of a substrate, the tact time for each single substrate is lengthened.

The present invention was conceived in view of the above described drawbacks, and it is an object thereof to provide a liquid droplet discharging method and a liquid droplet discharging apparatus that enable an extremely precise pattern to be formed on a substrate using a simple structure.

A liquid droplet discharging method according to the present invention includes steps of: preparing computer aided design (CAD) data that is specified by a combination of a plurality of vector data, in accordance with a configuration of a pattern that is formed by discharging a liquid droplet from a liquid droplet discharging device onto a substrate; preparing bitmap data that specifies discharging positions of the liquid droplet using an XY matrix based on the CAD data; preparing liquid droplet discharging data used for discharging the liquid droplet based on the bitmap data; and forming the pattern by driving the liquid droplet discharging device in accordance with the liquid droplet discharging data.

The “liquid droplet discharging device” has a function of changing the volume inside the discharging heads in accordance with a predetermined voltage waveform that is supplied to piezoelectric elements or the like, and discharging the liquid droplet that has been pressed in accordance with this. Note that the liquid droplet discharging device is not limited to an electromechanical converter that uses a piezoelectric element or the like, and, for example, a device that uses a thermoelectric converter as an energy generator may be used, or else continuous methods and electrostatic absorption methods such as pressure vibration types and electrification control types may be used.

The “liquid droplet discharging data” is data that is used for supplying the voltage waveform to the liquid droplet discharging device, namely, data used for controlling the discharge of the liquid droplet by the liquid droplet discharging device. Data used for moving the discharging head and the substrate relatively to each other is contained in this liquid droplet discharging data, namely, the liquid droplet discharging data is also used for determining the discharging position of the liquid droplets on the substrate. The data format of this liquid droplet discharging data is a time series data format formed using “0” and “1”, and is stored in read only memory (ROM) or random access memory (RAM).

The “pattern” is formed by discharging a material that is capable of being discharged in droplet form onto predetermined positions on a substrate. The term “pattern” refers to pixel patterns of RGB color filters formed by red (R), green (G), and blue (B), circuit patterns having, for example, resistance, capacitance formed by a capacitative element such as a condenser, and inductance such as antennas and coils having a labyrinth structure, patterns having switching elements such as thin film transistors (TFT) having semiconductors and pixel electrodes that are connected to the switching elements and the like, and oriented film materials and liquid crystal materials that require localized discharges and the like. The term “switching element” refers to elements that are formed using a material that is capable of being discharged as a liquid droplet.

The “substrate” is the object of the liquid droplet discharge on which a pattern is formed by discharging the above described liquid droplet. A variety of materials may be used for the substrate. For example, if transparency is required a substrate such as glass or the like may be used, while if transparency is not required a metal substrate or the like may be used. There are no particular restrictions on the size of the substrate and, in the present invention in particular, the term “substrate” refers to a large size substrate in excess of one meter.

According to the present invention, by using a computer provided with a display section such as a monitor and an input section such as a keyboard, it is possible to prepare in advance as CAD data a pattern formed by the above described discharge of a liquid droplet.

Moreover, it is possible to prepare bitmap data by converting the CAD data that has been prepared in this way.

After the liquid droplet discharging data has been prepared based on this bitmap data, by then making a discharge from a discharging head onto a predetermined position on the substrate based on the liquid droplet discharging data, it is possible to form a pattern on the substrate.

It is possible that: the pattern is formed by laminating a plurality of functional layers each having predetermined functions; the CAD data has a plurality of layer data that correspond to the functional layers; the bitmap data are prepared based on the plurality of layer data; the plurality of liquid droplet discharging data is prepared based on the plurality of bitmap data; and the pattern, which is formed by the plurality of functional layers, is formed by driving the liquid droplet discharging apparatus in accordance with the plurality of liquid droplet discharging data.

The term “functional layers” refers to each of the layers that make up the pattern, and refers, for example, to each layer of the aforementioned inductance, capacitance, resistance, switching elements, and the like. Namely, the above described pattern is formed by laminating each of these functional layers.