Scan circuit, display substrate, and display apparatus

A display substrate, comprising a scan circuit, a first reference signal line in a third region, and at least three clock signal lines arranged in a fourth region;

• wherein the scan circuit comprises a plurality of stages, wherein a respective stage of the scan circuit comprises a respective scan unit configured to provide a control signal to at least a row of subpixels;
• wherein the respective scan unit comprises an input subcircuit configured to receive from an input terminal a start signal or an output signal from a previous scan unit of a previous stage, a first processing subcircuit, a second processing subcircuit, and an output subcircuit configured to output an output signal from an output terminal;
• wherein the output subcircuit comprises a first output transistor;
• wherein the input subcircuit comprises a first input transistor and a second input transistor sequentially coupled between an input terminal and a first node;
• and
• the first node is coupled to a gate electrode of the first output transistor;
• wherein the first processing subcircuit comprises a first switch transistor and a second switch transistor coupled between the first node and a first reference terminal;
• and
• the first reference terminal is configured to receive a first reference signal;
• wherein a first output transistor and a second output transistor of the output subcircuit are arranged in a first region;
• input transistors, switch transistors, and control transistors of the respective scan unit are arranged in a second region;
• capacitors of the respective scan unit are arranged in the third region;
• and
• the fourth region, the second region, the first region, and the third region are sequentially arranged;
• wherein the second processing subcircuit is electrically connected to the first processing subcircuit;
• and
• the second processing subcircuit is configured to receive a second reference signal, and configured to output the second reference signal to the output subcircuit.