1. A range image generating apparatus comprising: a plurality of image pickup units having an optical system which forms images of subjects and image sensors which capture the images of the subjects formed by the optical system with two-dimensionally arrayed light receiving elements as electric signals; a first image capturing device which captures from each of the plurality of image pickup units an image of the subject formed by light in a first wavelength range as a first image; a second image capturing device which captures from at least one of the plurality of image pickup units an image of the subject formed by light in a second wavelength range as a second image; a first range image generating device which generates a first range image having values of pixels as distance data indicating a distance on the basis of a plurality of first images captured by the first image capturing device; a second range image generating device which generates a second range image having values of pixels as distance data indicating a distance on the basis of a second image captured by the second image capturing device; a third range image generating device which generates a third range image on the basis of the first range image and the second range image; and a recording device which records the third range image onto a recording medium, further comprising a light radiating device which irradiates the subject with light in the second wavelength range, wherein the second image capturing device irradiates the subject with light in the second wavelength range by using the light radiating device and captures an image of the subject formed by the reflected light thereof as the second image, wherein the first range image generating device is a range image generating device using a stereo matching technique which detects, from the plurality of first images, corresponding points indicating image points for the same object point, figures out the distance to the object point on the basis of the parallax of the corresponding points, and generates the first range image by using distance data indicating the distance as values of the pixels of the corresponding points, wherein the second range image generating device is a range image generating device using a TOF technique which figures out the distance to the object point having each pixel as the image point on the basis of the second image representing pixel values according to the length of time taken by the light of the second wavelength range to irradiate the subject and reach the image pickup units, and generates the second range image by using the distance data indicating the distance as the value of each pixel, wherein the third range image generating device generates the third range image by interpolating the first range image with the second range image, wherein the third range image generating device applies distance data obtained from pixels corresponding to the second range image to distance data for pixels whose distance could not be calculated in the generating of the first range image.