Abstract: The light source device includes at least one excitation light source which emits primary light, a light conversion member which emits secondary light that contains the primary light and wavelength-converted light obtained by converting a wavelength of at least part of the primary light, a sensor which detects the primary light and the wavelength-converted light, and a controller which obtains a first signal which is a signal indicating the detected primary light and a second signal indicating the wavelength-converted light detected by the sensor. The controller determines an operation safety parameter based on a ratio of an output value of the first signal to an output value of the second signal, and controls the at least one excitation light source based on the operation safety parameter with respect to a predetermined threshold or an amount of change of the operation safety parameter from that during normal operation.

Abstract: The piezoelectric device comprises a piezoelectric vibrating piece having a base portion, a pair of vibrating arms extending in a specified direction from the base portion, and a pair of connection portions disposed on the pair of the supporting arms; a package having a bottom surface which accommodates the piezoelectric vibrating piece and side faces surrounding the bottom surface, in which a pair of electrode pads corresponding to the connection portions are formed on the bottom surface; and adhesive for bonding the pair of the electrode pads with the pair of connection portions. One electrode pad and the other electrode pad, with adhesive applied to the electrode pads, are shifted with respect to each other in a predetermined direction.

Abstract: The piezoelectric devices allow outside-in adjustment of their vibration frequency. An exemplary piezoelectric device includes a tuning-fork type piezoelectric vibrating piece mounted inside a package. The vibrating piece has a base fabricated of a piezoelectric material, a pair of vibrating arms extending parallel from the base in a predetermined direction, and a frequency-adjustment unit situated on the distal ends of the vibrating arms. The package includes first metal films on the inner main surface thereof where an external laser beam can be irradiated. The frequency-adjustment unit includes a transparent region extending in a predetermined direction, allowing the laser beam, passing through the lid of the package, to be incident on second metal films by passing through the transparent regions. The laser beam also can be incident on first metal films without also being incident on the second metal films, by passing through the lid but not through the transparent regions.

Abstract: Piezoelectric devices are disclosed that allow outside-in adjustment of vibration frequency produced by the devices. I.e., the vibration frequency can be increased or reduced. An exemplary piezoelectric device includes a tuning-fork type piezoelectric vibrating piece mounted inside a package. The vibrating piece has a base fabricated of a piezoelectric material, a pair of vibrating arms extending parallel from the base in a predetermined direction, and a frequency-adjustment unit situated on the distal ends of the vibrating arms. The package includes first metal films disposed on the inner main surface of the package at a location where a beam from an external laser can be irradiated. The frequency adjustment unit includes a transparent region that extends in a predetermined direction for allowing the laser beam, passing through the lid of the package, to be incident on second metal films by passing through the transparent regions.

Abstract: The piezoelectric device comprises a piezoelectric vibrating piece having a base portion, a pair of vibrating arms extending in a specified direction from the base portion, and a pair of connection portions disposed on the pair of the supporting arms; a package having a bottom surface which accommodates the piezoelectric vibrating piece and side faces surrounding the bottom surface, in which a pair of electrode pads corresponding to the connection portions are formed on the bottom surface; and adhesive for bonding the pair of the electrode pads with the pair of connection portions. One electrode pad and the other electrode pad, with adhesive applied to the electrode pads, are shifted with respect to each other in a predetermined direction.