Abstract: In an interferometric device using a coherent beam and an image pickup camera, a protective glass for the detector surface is needed on the incident side of the pickup unit of the image pickup camera, and this gives rise to interference fringes which constitute noise. To solve this problem, a dustproof container is configured also to cover an imaging lens system arranged on the incident side of the pickup unit of the image pickup camera, and the pickup unit of the image pickup camera is arranged in this container. By assigning the function of the protective glass for the detector surface in the conventional configuration to the imaging lens system, the protective glass is made unnecessary.

Abstract: Methods and apparatus are disclosed for reducing output ripple voltages in bandgap voltage reference circuits. Ripple rejection circuitry is connected to a supply voltage and a first control signal, such as from an amplifier. The ripple rejection circuitry provides a second control signal representative of a difference between the supply voltage and the first control signal. The second control signal is then used to generate a reference voltage output. The incorporation of the supply voltage component in the second control signal operates to reduce or suppress the effects of power supply ripple on the bandgap voltage output.