<p>An optical pattern detecting apparatus has a ball lens (2), a light emitting device such as LED (3) and a light receptor such as photodiode (4), the latter two (3, 4) being disposed side-by side with their optical axis substantially in parallel so that light from the light emitting device (3) is converged by the ball lens (2) onto barcode mark (7) and light reflected from said barcode mark (7) is guided by the same ball lens (2) to the light receptor (4); the apparatus can stably detect the barcode mark even at inclination of the apparatus to the surface of the barcode mark.</p>
