Abstract: There is provided a liquid discharge apparatus including: a print head including a first connector; a substrate unit including a second connector fitted to the first connector and a third connector different from the second connector; and a relay substrate including a first cable through which a first voltage signal supplied to the substrate unit propagates, a second cable through which a second voltage signal supplied to the substrate unit propagates, a fourth connector fitted to the third connector, a relay substrate front surface, and a relay substrate back surface opposite to the relay substrate front surface, in which the first cable and the second cable are electrically coupled to the relay substrate front surface, the fourth connector is provided on the relay substrate back surface, and the first voltage signal and the second voltage signal propagate to the fourth connector.

Abstract: There is provided a liquid discharge apparatus including a substrate unit, and includes a wiring substrate having a plurality of rigid members and flexible member, in which a first rigid member, and a second rigid member are positioned facing each other, a third rigid member laminated on a first surface of a third region of the flexible member is positioned such that a normal direction of a third front surface intersects a normal direction of a first front surface and a second front surface, the second connector is provided on a fourth rigid member laminated on a second surface of a third region of the flexible member, and a size of the third rigid member and a fourth rigid member is smaller than a size of the print head when a first discharge section is viewed from the first connector.

Abstract: The preset disclosure provides a catalyst layer that has a small contact resistance with a gas diffusion layer and excellent gas diffusion properties. The catalyst layer for a fuel cell has a uniform thickness and includes fibrous conductive members and catalyst particles. The fibrous conductive members are inclined relative to a surface direction of the catalyst layer, and a lengthwise direction of the fibrous conductive members, on average, matches a first direction.

Abstract: A liquid residual amount detection device (printing apparatus) of the invention includes an irradiation unit that performs irradiation of a detection light, and a reaction detection unit that detects a reaction by the detection light irradiated by the irradiation unit. An amount of liquid is detected based on an amount of the detection light that reaches the reaction detection unit.

Abstract: A liquid residual amount detection device (printing apparatus) of the invention includes an irradiation unit that performs irradiation of a detection light, and a reaction detection unit that detects a reaction by the detection light irradiated by the irradiation unit. An amount of liquid is detected based on an amount of the detection light that reaches the reaction detection unit.