Abstract: A polyester resin contains a dicarboxylic acid constituent unit and a diol constituent unit, wherein more than 0% by mol and 20% by mol or less of the diol constituent unit is a unit originated from a diol having a cyclic acetal skeleton; 70 to 98% by mol of the diol constituent unit is a unit originated from a diol having an alicyclic skeleton; the diol constituent unit comprises a unit originated from ethylene glycol; 80% by mol or more of the dicarboxylic acid constituent unit is a unit originated from terephthalic acid; and the polyester resin has a physical property indicated by the following (A): (A) the minimum value of the semi-crystallization time is 600 s or less based on a depolarized light intensity method when the polyester resin is melted at 280° C. and crystallized at a constant temperature of 150 to 230° C.

Abstract: An electro-optical composite connector includes a receptacle connector including a receptacle housing to be mounted on a first board, a receptacle shell for covering the receptacle housing, and a receptacle terminal arranged on the receptacle housing; and a plug connector including a plug housing for holding an optical fiber, a plug shell for covering the plug housing, and an optical module to be connected to the optical fiber. The optical module includes a second board; a light receiving/emitting element mounted on one surface of the second board; at least one of a plug terminal and a land mounted on the one surface of the second board for transmitting a signal relative to the receptacle terminal; and a grounding surface formed on the other surface of the second board opposite to the one surface. The grounding surface is electrically connected to an inner wall of the plug shell.

Abstract: An electro-optical composite connector includes a receptacle connector including a receptacle housing to be mounted on a first board, a receptacle shell for covering the receptacle housing, and a receptacle terminal arranged on the receptacle housing; and a plug connector including a plug housing for holding an optical fiber, a plug shell for covering the plug housing, and an optical module to be connected to the optical fiber. The optical module includes a second board; a light receiving/emitting element mounted on one surface of the second board; at least one of a plug terminal and a land mounted on the one surface of the second board for transmitting a signal relative to the receptacle terminal; and a grounding surface formed on the other surface of the second board opposite to the one surface. The grounding surface is electrically connected to an inner wall of the plug shell.