An imaging device includes an image sensing device, a lens array, and a light-channel plate from the image side to the object side of the imaging device. The image sensing device includes a number of image sensors continuously arranged. The lens array includes a number of lenses. The light-channel plate defines a number of light channels. Each lens is received in a corresponding light channel and aligned with a corresponding image sensor. The imaging device also includes a storing device, a distance sensor and an image processor. The storing device stores a predetermined object distance. The distance sensor is configured for sensing a current object distance and controlling the imaging sensors to sense images if determining the current object distance is larger than the predetermined object distance. The image processor is connected with the image sensors and used for combing the images sensed by the image sensors.