Use of retaining member in a shaving unit for light guiding

Shaving unit (3) for an electric shaver (1), comprising:

• at least one hair-cutting unit (4) having an external cutting member (41) with hair-entry openings (45) and an internal cutting member (42) which is movable relative to the external cutting member (41) and covered by the external cutting member (41);
• a base member (6) having a hair-collecting chamber (61) arranged for collecting hairs cut by the hair-cutting unit (4);
• a supporting member (5) releasably mounted on the base member (5) and configured to support the hair-cutting unit (4), said supporting member (5) having a skin-contacting surface (51) arranged to contact a skin of a user during use of the shaving unit (3), said skin-contacting surface (51) at least partially surrounding the hair-cutting unit (4);
• a retaining member (7) connected to the supporting member (5) and configured to retain the hair-cutting unit (4) in an operational position relative to the supporting member (5), said operational position being between the skin-contacting surface (51) of the supporting member (5) and the retaining member (7);
• and
• at least one light source (81) configured to generate light for illuminating the skin of the user via at least a portion of the skin-contacting surface (51) of the supporting member (5) during use of the shaving unit (3);
• wherein:
• a portion (52) of the supporting member (5) comprising said portion of the skin-contacting surface (51) is optically transparent;
• the retaining member (7) has an optically transparent light-guiding portion (71);
• the light source (81) is arranged such that light generated by the light source (81) is optically coupled into the light-guiding portion (71) of the retaining member (7);
• and
• the light-guiding portion (71) of the retaining member (7) has a light-outcoupling surface (76) and is configured to guide the light received from the light source (81) and to outcouple the light via the light-outcoupling surface (76) in a direction towards the optically transparent portion (52) of the supporting member (5).