Abstract: A vital signal detecting apparatus comprises an attachable device to be attached to a finger, a sensor having a light-emitting device and a light-receiving device, and a transmitting circuit for transmitting a signal waveform as a pulse wave from the sensor to a pulse wave monitoring unit. The pulse wave detecting unit also has an attachment detecting circuit for detecting whether or not the attachable device is in an attached state by comparing a signal waveform obtained when the light-emitting device is on with a signal waveform obtained when the light-emitting device is off and an operation control circuit for controlling the operation of the sensor, the transmitting circuit and the attachment detecting circuit. Preferably, the light-transmitting plate is disposed above the light-emitting device and the light-receiving device to pass light therethrough, and the light transmitting plate may be an IR-cut filter capable of blocking light of wavelengths greater than 700 nm.

Abstract: White light projected from a white light source is divided into three light beams of primary colors, i.e., red, green and blue by a dichroic mirror. Three light beams projected from the dichroic mirror are made incident upon a micro-lens array and reflected on and modulated in a liquid crystal panel disposed beneath the micro-lens array. The liquid crystal panel is driven by a driver circuit which supplies color signals to the panel, thereby modulating the light beams in the panel. The modulated light beams are projected from the micro-lens array to a schlieren diaphragm which eliminates scattered light components from the light beams. The light beams then enter into a projection lens and display color images on the screen. Since light beams constituting a picture element consisting of red, green and blue colors are projected from a single micro-lens of the micro-lens array, a color image displayed on the screen has no blur among three primary colors.

Abstract: A two-dimensional optical scanner not affected by acceleration disturbances. The two-dimensional optical scanner includes a mirror section having at least one mirror surface formed thereon. A first frame is provided outside the mirror section with a first clearance therebetween. First springs connect the mirror section and the first frame and torsionally vibrating about an axis passing through the center of gravity of the mirror section. A second frame is provided outside the first frame with a second clearance therebetween, and second springs connect the first frame and the second frame. The second springs torsionally vibrate about an axis passing through the center of gravity of mirror section. Piezoelectric bimorphs 21, 22, 23, and 24 drive the optical scanner to impart a torsional oscillation to the first springs and the second springs.