Imagine a transparent optical scanning disc or drum with translucent pits embossed or drilled part way through one surface as a substitute for apertures. Imagine a linear modulated light source, such as a linear bank of LEDs, illuminating a portion of one edge of the transparent scanning element to transmit a linear light beam through the disc. As the transparent scanning element rotates about its axis, the linear light beam sequentially illuminates each translucent pit as it passes within the boundary of the beam, forming one scanning line.
All the light from the LEDs is concentrated into a single line, rather than spread out over the entire area of the display. Thus, in the case of a 32 × 48 pixel display, each pixel is 1/48 th of the brightness of the light source instead of 1/( 32 × 48 ) th of the brightness that a conventional opaque scanning element with apertures would provide.
A photosensor with a linear field of view could substitute for the light source for camera use. The photosensor would have an improvement in signal to noise ratio of as much as 32 times, since the area of view is limited by this amount compared to a photosensor with a rectangular field of view with a conventional opaque scanning element.
I have posted a description and illustration of this concept at http://www.taswegian.com/NBTV/images/TOSE.pdf .