Abstract: Some examples relate to database systems for electronic spreadsheets. In one specific example, a system includes a relational database and a document database that is separate from the relational database. The system can retrieve structural data from the relational database, where the structural data describes a column configuration for a set of columns of the electronic spreadsheet, and where the structural data describes a row configuration for a set of rows of the electronic spreadsheet. The system can also retrieve cell data from the document database. The system can then generate the electronic spreadsheet based on the structural data and the cell data, such that the electronic spreadsheet has the column configuration and the row configuration defined in the structural data, and has the cell data positioned in a set of cells located at intersections of the set of rows and the set of columns.

Abstract: A power saving welding helmet includes a helmet shell and a lens device. The helmet shell includes a mounting hole to contain the lens device. The lens device has an inner surface and an outer surface, and includes a magnetic sensor, a filter control unit, and a filter lens. The control logic module controls the filter lens according to magnetic signals generated by the magnetic sensor. The filter lens includes a first LCD panel and a second LCD panel respectively controlled by different control signals. Therefore, a refresh time of the first LCD panel and a refresh time of the second LCD panel do not synchronize. A welder does not feel the first LCD panel or the second LCD panel flashing, and the welding experiences this as consistent darkness.

Abstract: A power saving welding helmet includes a helmet shell and a lens device. The helmet shell includes a mounting hole to contain the lens device. The lens device has an inner surface and an outer surface, and includes a magnetic sensor, a filter control unit, and a filter lens. The control logic module controls the filter lens according to magnetic signals generated by the magnetic sensor. The filter lens includes a first LCD panel and a second LCD panel respectively controlled by different control signals. Therefore, a refresh time of the first LCD panel and a refresh time of the second LCD panel do not synchronize. A welder does not feel the first LCD panel or the second LCD panel flashing, and the welding experiences this as consistent darkness.