Ink jet recording head

#1. Field of the Invention

#The present invention relates to an ink jet recording head for performing recording by discharging an ink droplet from a discharge port and by adhering the ink droplet onto a recording medium.

#2. Related Background Art

#FIG. 1A is a schematic plan view showing a fundamental construction of an ink jet recording head according to a first reference example, and FIG. 1B is a sectional view thereof;

#FIG. 2A is an enlarged plan view showing main part of the ink jet recording head according to the first reference example shown in FIG. 1A with partially omitted, and FIG. 2B is a sectional view taken along the line 2B-2B;

#FIG. 3A is an enlarged plan view showing main part of an ink jet recording head according to a second reference example with partially omitted, and FIG. 3B is a sectional view taken along the line 3B-3B;

#Now, embodiments of the present invention and reference examples will be explained with reference to the accompanying drawings.

#An ink jet recording head according to a first reference example is shown in FIGS. 1A and 1B and FIGS. 2A and 2B. As shown in FIGS. 1A and 1B, in a fundamental construction of the ink jet recording head, five ink supply ports 5 are formed in a single substrate 1, and cyan ink is supplied to the ink supply ports 2A and 2E, magenta ink is supplied to the ink supply ports 2B and 2D and yellow ink is supplied to the ink supply port 2C. A discharge port plate 9 to be jointed to the substrate 1 is provided with large liquid droplet discharge ports 3a for discharging large liquid droplets and small liquid droplet discharge ports 3b for discharging small liquid droplets with respect to the respective ink supply ports 2. Regarding the ink supply ports 2A and 2B, the large liquid droplet discharge ports 3a are disposed at a left side in FIGS. 1A and 1B and small liquid droplet discharge ports 3b are disposed at a right side in FIGS. 1A and 1B. Regarding the ink supply ports 2D and 2E, the small liquid droplet discharge ports 3b are disposed at a left side in FIGS. 1A and 1B and the large liquid droplet discharge ports 3a are disposed at a right side in FIGS. 1A and 1B, and, regarding the ink supply port 2C, the large ink droplet discharge ports 3a are disposed on both sides. Accordingly, if the substrate 1 is shifted in either direction along an arrangement direction of the ink supply ports 2 (left-and-right direction in FIGS. 1A and 1B), the order for discharging the ink colors onto a recording medium (not shown) becomes the same, thereby preventing generation of color unevenness.

#As shown in enlarged views of FIGS. 2A and 2B illustrating left side portions of FIGS. 1A and 1B, the large liquid droplet discharge port 3a is provided at one side of each ink supply port 2 and the small liquid droplet discharge port 3b is provided at the other side. The discharge ports 3a and 3b are communicated with a common liquid chamber 6 via pressure chambers 4a and 4b and ink flow paths 5a and 5b, respectively, and the common liquid chamber 6 is communicated with the ink supply ports 2. Electro-thermal converting elements (referred to as “heaters” hereinafter) 7a and 7b are disposed within the pressure chambers 4a and 4b, respectively. Incidentally, in this specification, a condition that the ink flow path is continued to the pressure chamber is generically referred to as “nozzle.” A cylindrical nozzle filter 8 integrally formed with the discharge port plate 9 is disposed in the vicinity of portions of the common liquid chamber 6 to which the ink flow paths 5a and 5b are connected.