Illumination device for a motor vehicle headlamp and/or for a rear lamp of a motor vehicle and/or for a signal lamp for a motor vehicle headlamp, for generating a light distribution or a partial light distribution or an intermediate light image, wherein the illumination device comprises an optical body, hereinafter referred to as TIR optical body, and a number of light sources, in particular LED light sources, wherein, for example, exactly one light source, or two or more than two light sources are provided, wherein the TIR optical body is made of an optically transparent material, wherein the TIR optical body has a light input region and a light output area, wherein light from the light sources fed into the TIR optical body via the light input region emerges at least partially via the light output surface, and wherein the TIR optical body is, in a first direction extending transversely to an optical axis of the TIR optical body, bounded by two mutually opposite boundary surfaces (4, 5), wherein the light input region has lateral coupling surfaces (110, 111) in a second direction transverse to the optical axis of the TIR optical body and transverse to the first direction, and wherein the light input region further comprises a central light coupling surface, the central light coupling surface being adjacent to or abutting the two lateral coupling surfaces (110, 111) and wherein light from the at least one light source can be fed into the TIR optical body via the central light input region as well as via the, in particular two, side input surfaces (110, 111), which light propagates in the TIR optical body and emerges from the TIR optical body as a light beam via the light output surface, and the or at least one of the side light coupling surfaces (110, 111) of the light coupling region being matched to upper and/or lower boundary surfaces (6, 7) of the TIR optical body in such a way that at the upper and/or lower boundary surface (6, 7) of the TIR optical body light rays that are reflected totally propagate, as seen in vertical sections through the TIR optical body, parallel to each other and preferably parallel to the optical axis of the TIR optical body, characterized in that the central light coupling surface comprises a, preferably smooth, base surface on which an optical structure is provided, which is formed such that light rays, when entering the TIR optical body via the central light coupling surface, are deflected by the latter, as seen in a projection to a plane which is defined by the optical axis and the first direction or is parallel to this plane, in such a way that these light rays propagate parallel to each other within the TIR optical body, as seen in this projection. wherein the TIR optical body is made of an optically transparent material, wherein the TIR optical body has a light input region and a light output area, wherein light from the light sources fed into the TIR optical body via the light input region emerges at least partially via the light output surface, and wherein the TIR optical body is, in a first direction extending transversely to an optical axis of the TIR optical body, bounded by two mutually opposite boundary surfaces (4, 5), wherein the light input region has lateral coupling surfaces (110, 111) in a second direction transverse to the optical axis of the TIR optical body and transverse to the first direction, and wherein the light input region further comprises a central light coupling surface, the central light coupling surface being adjacent to or abutting the two lateral coupling surfaces (110, 111) and wherein light from the at least one light source can be fed into the TIR optical body via the central light input region as well as via the, in particular two, side input surfaces (110, 111), which light propagates in the TIR optical body and emerges from the TIR optical body as a light beam via the light output surface, and the or at least one of the side light coupling surfaces (110, 111) of the light coupling region being matched to upper and/or lower boundary surfaces (6, 7) of the TIR optical body in such a way that at the upper and/or lower boundary surface (6, 7) of the TIR optical body light rays that are reflected totally propagate, as seen in vertical sections through the TIR optical body, parallel to each other and preferably parallel to the optical axis of the TIR optical body, characterized in that the central light coupling surface comprises a, preferably smooth, base surface on which an optical structure is provided, which is formed such that light rays, when entering the TIR optical body via the central light coupling surface, are deflected by the latter, as seen in a projection to a plane which is defined by the optical axis and the first direction or is parallel to this plane, in such a way that these light rays propagate parallel to each other within the TIR optical body, as seen in this projection.