An image display unit comprising: an image display panel that forms pixels to display an image; and a barrier liquid crystal panel that is arranged above the image display panel and forms slits (100 S) that serve as barriers to shield image light from the pixels of the image display panel, wherein the barrier liquid crystal panel includes a scan-side transparent electrode and a common-side transparent electrode, wherein the scan-side transparent electrode is formed of electrode groups (105a, 105b, 105c), each electrode group including a set of five electrodes consisting of one first electrode having an electrode width substantially half of the arrangement intervals of the pixels, two second electrodes arranged on the respective sides of the first electrode, the second electrodes each having an electrode width substantially one fourth of the arrangement intervals of the pixels, and two third electrodes arranged on the respective sides of the two second electrodes opposed to the first electrode, the third electrodes each having an electrode width substantially one fourth of the arrangement intervals of the pixels, and a gap part is provided between sets of the electrode groups, the gap part having a width substantially half of the arrangement intervals of the pixels, wherein in a first mode as two dimension display function that emits image light for 2D display from the pixels of the image display panel, the first electrode, the second electrodes, the third electrodes, and the common-side transparent electrode are fixed to a common potential or set to an OFF state wherein said slits serving as barriers are not formed, wherein in a second mode as a three dimension display function that emits image light for 3D display from each of pixels for left eye and pixels for right eye of the pixels of the image display panel, an alternating potential is applied to the first electrode and the second electrodes, and the third electrodes and the common-side transparent electrode are fixed to a common potential, wherein in a third mode as a viewing angle control function that controls a viewing angle of the image light from the pixels of the image display panel, an alternating potential is applied to the second electrodes and the third electrodes, and the first electrode and the common-side transparent electrode are fixed to a common potential, and wherein the barrier liquid crystal panel appropriately controls the applied potential according to an operation mode that is specified to change a slit width and a slit pitch of the slits (100 S) formed in the barrier liquid crystal panel, thereby switching one of the first to third modes to another one of the first to third modes. an image display panel that forms pixels to display an image; and a barrier liquid crystal panel that is arranged above the image display panel and forms slits (100 S) that serve as barriers to shield image light from the pixels of the image display panel, wherein the barrier liquid crystal panel includes a scan-side transparent electrode and a common-side transparent electrode, wherein the scan-side transparent electrode is formed of electrode groups (105a, 105b, 105c), each electrode group including a set of five electrodes consisting of one first electrode having an electrode width substantially half of the arrangement intervals of the pixels, two second electrodes arranged on the respective sides of the first electrode, the second electrodes each having an electrode width substantially one fourth of the arrangement intervals of the pixels, and two third electrodes arranged on the respective sides of the two second electrodes opposed to the first electrode, the third electrodes each having an electrode width substantially one fourth of the arrangement intervals of the pixels, and a gap part is provided between sets of the electrode groups, the gap part having a width substantially half of the arrangement intervals of the pixels, wherein in a first mode as two dimension display function that emits image light for 2D display from the pixels of the image display panel, the first electrode, the second electrodes, the third electrodes, and the common-side transparent electrode are fixed to a common potential or set to an OFF state wherein said slits serving as barriers are not formed, wherein in a second mode as a three dimension display function that emits image light for 3D display from each of pixels for left eye and pixels for right eye of the pixels of the image display panel, an alternating potential is applied to the first electrode and the second electrodes, and the third electrodes and the common-side transparent electrode are fixed to a common potential, wherein in a third mode as a viewing angle control function that controls a viewing angle of the image light from the pixels of the image display panel, an alternating potential is applied to the second electrodes and the third electrodes, and the first electrode and the common-side transparent electrode are fixed to a common potential, and wherein the barrier liquid crystal panel appropriately controls the applied potential according to an operation mode that is specified to change a slit width and a slit pitch of the slits (100 S) formed in the barrier liquid crystal panel, thereby switching one of the first to third modes to another one of the first to third modes.