TECHNOLOGY FOCUS - IMAGING AND COMMUNICATION - Preferred Component: A polymeric light emitting component has an anode, cathode and light emitting layer containing the polymer compound and provided between the electrodes.    TECHNOLOGY FOCUS - POLYMERS - Preferred Polymer: The benzo thiadiazole-containing repeating unit of formula (1) is given by formula (1a). The polymer compound further contains repeating unit of formula (2): -Ar5-Z2-.R1-R4=H, alkyl, alkoxy or aryl group;R5,R6=H, alkyl or aryl;o,p=1 or 2;Ar5=(un)substituted bivalent heterocyclic group preferably group of formula (70) more preferably group of formula (2E), (un)substituted arylene group preferably group of formula (60) more preferably group of formula (2A-2D), or (un)substituted bivalent aromatic amine group,;Z2=-CR3=CR4- or -C=?C-, preferably -CR3=CR4-;R3,R4=H, alkyl, aryl, monovalent heterocyclic or cyano group;ring A,ring B=(un)substituted aromatic hydrocarbon ring;Rw,Rx=H, alkyl, alkoxy, alkylthio, alkyl silyl, alkylamino, aryl, aryloxy, aryl alkyl, aryl alkoxy, aryl alkenyl, aryl alkynyl, aryl amino, monovalent heterocyclic, acyl, substituted carboxyl or cyano group;R7=H, alkyl or aryl;ring C,ring D=aromatic ring optionally having alkyl, alkoxy, alkylthio, alkyl silyl, alkyl amino, aryl, aryloxy, aryl alkyl, aryl alkoxy, aryl alkenyl, aryl alkynyl, acyl amino, monovalent heterocyclic, acyl, acyloxy, substituted carboxyl or cyano group;E,Y'=O or S;R8,R9=alkyl, alkoxy or aryl;anda,b=0 or 1.Preferred Composition: A composition contains the polymer compound and other compound having number average molecular weight of 103-108 by polystyrene conversion. A liquid composition contains the polymer compound and solvent. A thin film contains the polymer compound. EXAMPLE - 4-formyl phenyl boric acid (in g) (3.3) and dibrom compound monomer (4.86) were reacted in presence of toluene (80). Tetra-n-butyl ammonium bromide (1.6) was added and subsequently 16.7 wt.% sodium carbonate aqueous solution (50 ml) was added. The solution was heated with tetrakis (triphenyl phosphine)palladium (1.2) for 20 hours, to obtain monomer of formula (1). The obtained monomer (0.107), monomer (0.61) of formula (2) and monomer (0.293) of formula (3) were dissolved in dehydrated toluene (50) and bubbled with argon gas. Subsequently, tertiary butoxy potassium (0.45) was added and reacted at 95degrees C for 2 hours. After completion of reaction, the reaction solution was neutralized with acetic acid and reprecipitated. The precipitate was filtered, collected, dried and purified to obtain polymer compound. The weight average molecular weight and number average molecular weight of the obtained polymer compound was 1.4x 104 and 7.1x 103, respectively. The polymer compound exhibited red fluorescence.