Abstract: A method of reading a bar code having guard bars at both sides thereof without fail even if the bar code image is highly distorted. An image region taken in by a CCD camera is scanned in horizontal and/or vertical directions to find out a first guard bar in the bar code. Then, a first scanning line for reading the bar code is set in a direction perpendicular to the first guard bar. The bar code is scanned along the first scanning line. If the first scanning line goes out of the bar code region, the first scanning line is traced back to a bar which is last read. Another scanning line starting from the last read bar and extending perpendicularly thereto is set to read the rest of the bar code. This process is repeated until the second guard bar is detected and a whole bar code is completely read. The first scanning line may be set, so that it only reads a predetermined number of bars and the rest of the bar code is read by new scanning lines starting from the last read bar.

Abstract: In an optical information reading apparatus in which the degree of freedom with which the apparatus is shaped is improved, a mirror for bending a reflected light which has passed through an image forming lens is disposed between the image forming lens and an image sensor, whereby the provision of the image sensor at a position which is not on a line extending between the image forming lens and the mirror is enabled. That is, a space located beyond the line extending between the image forming lens and the mirror can be freely altered, thus increasing the degree of freedom with which a casing is shaped.

Abstract: Apparatus for optically reading printed information by radiating light onto printed information to be reflected thereby, receiving the reflected light through an optical system and converting the image of the reflected light into a corresponding electric signal. The light source employs red light emitting diodes which radiate highly bright red light having a wavelength peak at about 660 nm so that the image sensor can receive a highly contrasting reflected light from the information printed in black on a white base. The light source further or alternatively employs infrared light emitting diodes for radiating the light having a peak wavelength at about 925 nm so that the image sensor can also received a highly contrasting reflected light from information printed in black on a blue or green base.