An image transmission device and method, a transmitting device and method, a receiving device and method, and robot apparatus are capable effectively transmitting the image data of multiple channels by using the existing systems which are formed on the premise of transmitting and receiving of the image data through single transmission line. An engaging tube portion is integrally formed with an upper part of the bellows tube portion of the dust cover. A front end of the main body is installed with a plurality of terminal grooves A hollow cover is formed at the rear end of the connector. The capillary test space is positioned to be in contact with the fluid in the reservoir after the fluid has accumulated to a predetermined transfer volume of fluid.