Abstract: An endoscope includes: a connector portion for electrically coupling to an external connector. The connector portion includes: a base portion having a tubular shape; and a tubular sleeve portion extending from the base portion, at least a part of an end portion of the sleeve portion being provided with a cutout portion. When a water-resistant cap is installed at the connector portion, the endoscope takes any state of a first state where an abutting portion of the water-resistant cap configured to abut on the sleeve portion abuts on the sleeve portion on a side of the base portion with respect to the cutout portion to hold an airtightness between the water-resistant cap and the connector portion, and a second state where the abutting portion abuts on or faces the sleeve portion including the cutout portion to make non-airtight between the water-resistant cap and the connector portion.

Abstract: An ultrasound transducer of the present invention includes elements each provided with an electromechanical conversion element that converts an electric signal inputted between a first electrode and a second electrode into vibration, an array section made up of n elements in a row direction and m elements in a column direction (nm) arranged in a matrix form, and an array forming section that switches between a one-dimensional array state column-wise made up of m element groups formed by electrically connecting the first electrode terminals neighboring in the row direction out of the first electrode terminals in the element groups arranged on the same column and a one-dimensional array state row-wise made up of n element groups formed by electrically connecting the first electrode terminals neighboring in the column direction out of the first electrode terminals in the element groups arranged on the same row in the array section.