Abstract: A calibration device (CC) is coupled to a balanced circuit device (MC) comprising first and second outputs respectively provided with first (Z1) and second (Z2) load impedance means. This calibration device (CC) comprises adjusting means (ADM) arranged to adjust said first (Z1) and second (Z2) load impedance means into a load imbalance for linearization purposes, and a coupling means (CM) inserted between the load impedance adjusting means (ADM) and the first and second outputs and arranged to selectively couple the load impedance adjusting means (ADM) to only a chosen one of the first and second outputs, so that the load impedance adjusting means (ADM) is connected in parallel either to the first load impedance means (Z1) or to the second load impedance means (Z2).

Abstract: To increase an amount of the light that can be used for the display efficiently in the total amount of the emitted light in the liquid crystal display device having the surface lighting device such as the front-light. The light (a) becomes the light component of the linearly polarized light by passing the retardation plate (11a). In the reflective polarizer (11b), only the light (b) that is a component of the polarization axis of the reflective polarizer (11b) passes through the reflective polarizer (11b) to enter into the end portion of the light guide (12). The light that is a component other than the component of the polarization axis of the reflective polarizer (11b) is reflected on the reflective polarizer (11b). The light reflected on the reflective polarizer (11b) changes from the linearly polarized light to the circularly polarized light by passing through the retardation plate (11a).