A machine for projecting the images of opaque objects or transparencies on a screen.
A machine for projecting the images of opaque objects or transparencies on a screen.
透反射两用幻灯机用于将不透明或透明物体的影象投影到屏幕上的机器
A machine for projecting the images of opaque objects or transparencies on a screen.
透反射两用幻灯机用于将不透明或透明物体的影象投影到屏幕上的机器