Filters for electronic display device

A filter for an electronic display device comprising a squarylium compound represented by the general formula (I):

• 13
• wherein X represents a nitrogen atom or an oxygen atom;
• Q represents a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom;
• R1 represents a hydrogen atom, an alkyl group optionally having substituent(s), an aryl group optionally having substituent(s), an aralkyl group optionally having substituent(s), or a heterocycle group optionally having substituent(s), provided that when X is an oxygen atom, then R1 is absent;
• R2 represents a hydrogen atom, a halogen atom, an alkyl group optionally having substituent(s), an alkoxyl group optionally having substituent(s), an aralkyl group optionally having substituent(s), an aryl group optionally having substituent(s), a nitro group, a cyano group, a hydroxyl group, an amino group optionally having substituent(s), or a heterocycle group optionally having substituent(s);
• R3 and R4 are the same or different, and represent a hydrogen atom, an alkyl group optionally having substituent(s), an aryl group optionally having substituent(s), an aralkyl group optionally having substituent(s), or a heterocycle group optionally having substituent(s), or R3 and R4 may be taken together with an adjacent carbon atom to form an alicyclic hydrocarbon ring optionally having substituent(s), or an heterocyclic ring optionally having substituent(s), provided that when Q is a nitrogen atom, then R4 is absent and, when Q is an oxygen atom or a sulfur atom, then R3 and R4 are absent;
• R5 represents a hydrogen atom, an alkyl group optionally having substituent(s), an aryl group optionally having substituent(s), an aralkyl group optionally having substituent(s), or a heterocycle group optionally having substituent(s);
• R6 represents a halogen atom, an alkyl group optionally having substituent(s), an alkoxyl group optionally having substituent(s), an aralkyl group optionally having substituent(s), an aryl group optionally having substituent(s), a nitro group, a cyano group, a hydroxyl group, an amino group optionally having substituent(s), or a heterocycle group optionally having substituent(s);
• and m represents an- integer of 0-2, wherein when m is 2, then respective R6S may be the same or different, or further two R6s may be taken together with two carbon atoms to which each R6 is adjacent to form an aromatic ring optionally having substituent(s).