Mid-air images are formed in the air by the reflection and refraction of light emitted by a light source, which allows the user to view the floating image in real space without wearing special equipment. However, conventional mid-air image optical systems have some weaknesses, such as the need to suitably adjust the height of the viewpoint position depending on its optical arrangement. We propose an optical design that can be installed simply by placing it on a glossy plane, on which an upright mid-air image can be displayed and which is smaller than the existing system.