Abstract: This optical coupler for coupling a plurality of visible light beams having different wavelengths includes: a substrate made of a material different from lithium niobate; and an optical coupling function layer formed on a main surface of the substrate. The optical coupling function layer includes: two multimode-interference-type optical coupling parts; optical-input-side waveguides and an optical-output-side waveguide connected to one multimode-interference-type optical coupling part, and optical-input-side waveguides and an optical-output-side waveguide connected to the other multimode-interference-type optical coupling part. The multimode-interference-type optical coupling parts, the optical-input-side waveguides, and the optical-output-side waveguides are made of a lithium niobate film.

Abstract: It is an object of the present invention to provide techniques for shortening a time required for establishing a correspondence between an electronic shelf label and a product. In an electronic shelf label system (1), in response to receipt of a correspondence cancellation signal in an electronic shelf label (5), a hardware information screen (S2) including a device code (8d) appears. Thus, in the electronic shelf label (5) in an unlinked state, the device code (8d) is kept being displayed. Accordingly, in a subsequent linking process for establishing a correspondence between the electronic shelf label (5) and a product, a process for causing the electronic shelf label (5) to display the device code (8d) is unnecessary, to thereby significantly shorten a time required for establishing a correspondence between the electronic shelf label (5) and a product.

Abstract: A data reading apparatus includes a TV camera with a deflecting mechanism for reading codified data. The scanning direction of the TV camera is rotated by using the deflecting mechanism.