Code disc support, grating assembly and optical encoder

The utility model discloses a coded disc support, a grating assembly, an optical encoder and a coded disc support, the coded disc support and the grating assembly are used for bearing and fixing a reflective coded disc, and the coded disc support comprises a support seat (1) made of plastic and a coded disc bearing plate (2); a lower first through hole (11) penetrating through the upper end and the lower end is formed in the middle of the support base (1), and a second through hole (21) penetrating through the top face and the bottom face is formed in the middle of the coded disc bearing plate(2). The coded disc bearing plate (2) is fixed at the lower end (13) of the support seat (1), the first through hole (11) is communicated with the second through hole (21), the support seat (1) and the coded disc bearing plate (2) are sleeved on a motor rear shaft extending out of a rear end cover of a motor through the first through hole (11) and the second through hole (21), and accordingly thereflective coded disc is