Patent ID: 6994427

Claim:
An ink jet recording head for discharging ink drop onto a recording medium, comprising: a plurality of cavities configured to hold ink; a plurality of piezoelectric elements disposed on the cavities respectively and configured to press each of the cavities; and a plurality of ink discharge orifices arranged on a ink discharging surface as a matrix and each connected to the cavities respectively, wherein the ink jet recording head is designed to satisfy the following relational expression: K 0 ·N a0 ·A b0 ·α c0 ·Spin d0 ·( Scav/Spin ) e0 ·( Spzt/Scav ) f0 ≦0.1 where a 0 =1.87686, b 0 =0.31786, c 0 =−0.18649, d 0 =−1.09273, e 0 =−3.97019, f 0 =0.93332 and K 0 =0.05307 are satisfied when N is a number of layers in one of the piezoelectric element, A is a number of active layers in one of the piezoelectric element, α is an angle [°] which is one of internal angles of virtual lattices containing one of the cavity and forming the matrix and which is not higher than 90°, Spin is an area [mm 2 ] occupied by one lattice in the matrix, Scav is an area [mm 2 ] occupied by the cavity contained in one lattice in the matrix, and Spzt is an area [mm 2 ] occupied by an active portion of the piezoelectric element provided in accordance with one lattice in the matrix.