1. Field of the Invention
This invention relates to a camera having a digital exposure value display device.
2. Description of the Prior Art
A digital exposure value display device for displaying a manually set or automatically controlled shutter time value or aperture value as a digital value in the viewfinder of a camera is known. Such digital exposure value display device requires a highly accurate reference voltage generating circuit for generating a number of reference voltages of different levels to quantize a voltage associated with the exposure value to be displayed.
Also known is a digital fixed point match type exposure display device for digitally displaying whether a manually set shutter time or aperture value provides a proper exposure or an under-exposure or an over-exposure, by the use of a plurality of display elements such as lamps or the like. This has, for example, three LEDs (light emitting diodes) and displays the proper exposure by the turn-on of a first LED, the under-exposure by the turn-on of a second LED, and the over-exposure by the turn-on of a third LED. Such digital fixed point match type exposure display device also compares a voltage representing a manually set exposure value with a plurality of reference voltages and necessarily requires a highly accurate reference voltage generating circuit.
Therefore, a camera provided with both the digital exposure value display device and the digital fixed point match type exposure display device requires two highly accurate reference voltage generating circuits and this results in a high cost of the camera.
Also, a camera which permits selection of automatic exposure setting and manual exposure setting requires a reference voltage generating circuit for an exposure value display device which displays an automatically controlled shutter time or aperture value as a digital value in the viewfinder of the camera, and a reference voltage generating circuit for generating a voltage corresponding to a set value provided by rotation of a shutter dial or the like. Again in the case, there is a disadvantage that two highly accurate reference voltage generating circuits are required.
USPTO Backgrounds
USPTO Backgrounds