A face authentication device is provided that can perform personal identification with high accuracy regardless of an imaging environment for an input face image. The insulator includes a rear body portion, a middle body portion and a large-diameter portion located between and protruded radially outwardly from the rear and middle body portions to define a rear shoulder section connected to the rear body portion and a front shoulder section connected to the middle body portion. The estimating unit estimates a length in a transport direction of the sheet as a detection target on the basis of individual detection results generated by the plural detecting units. The planer and thicknesser also comprises a cover mounted above the upper table capable of being moved from a first position where it covers a portion of the cutting drum to a second position where it does not cover a portion of the cutting drum. The dimmer control device further compensates for warmup and startup transistions by directing input voltage through relays that provide full voltage until desired voltagecurrent phase relation is established within acceptable tolerance levels.