A data conversion apparatus is provided as a data transmitting apparatus in a data communication system which achieves pseudo interactive communications by using one-way communications between the data transmitting apparatus and a plurality of data receiving apparatuses. The data conversion apparatus converts documents stored inside into images to be displayed on the screen, such as a TV screen. In doing so, if the document includes character strings or image information as link destination information which specifies another document as a link destination, the data conversion apparatus adds a supplementary design into the image of the link destination information for the viewer to recognize such information.