Optics: measuring and testing – Photometers – Photoelectric
Reexamination Certificate
2002-01-18
2004-04-13
Font, Frank G. (Department: 2877)
Optics: measuring and testing
Photometers
Photoelectric
C356S213000, C356S219000
Reexamination Certificate
active
06721044
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an exposure meter used for photographing, and in particular, to an exposure meter for incident- and reflected-light photometry which can be favorably used by a professional photographer or in a photographic studio.
2. Description of Related Art
Exposure meters for incident- and reflected-light photometry which are capable of measuring light by simply switching light to be measured to incident light on an object or reflected light from the object have been largely used by professional photographers, and various exposure meters are commercially available. In recent years, an exposure meter for incident- and reflected-light photometry has been known which incorporates a display means for digitally displaying various exposure conditions based on photometric results in order to facilitate the setting of exposure values to a still camera or a cinecamera, and a finder for visualizing a photometric area of spot light in order to allow the photometry of spot light with no parallax (refer to Japanese Patent Preliminary Publication No. Hei 8-128892). Moreover, another exposure meter has also been known in which the emission of a flash and the amount of flashlight can be controlled, by cordless operation, through a built-in remote control adjusting device (refer to Japanese Patent Publication No. Hei 7-122591).
Any of well-known exposure meters for incident- and reflected-light photometry is designed so that a light receiving section is fixedly mounted to an exposure meter body and cannot be dismounted. Thus, the problem arises that although in recent years the display of a photometric value has been digitized and a display function of the exposure meter has been diversified, such display cannot be used with a simple exposure meter for incident- and reflected-light photometry.
Furthermore, the well-known exposure meter for incident- and reflected-light photometry is not always satisfactory for a camera used by a professional photographer because the kind of exposure value to be set to the camera is highly limited. In the photometry of spot light, there is inconvenience that even though a photometric area is determined by looking through a finder, a display window for the exposure value is located at a position different from that of the finder and thus a photographer's eye must be moved from the finder to the display window in order to see the exposure value.
In any of the well-known exposure meters, the remote control device for flashlight is housed in the exposure meter body and thus the cost of the exposure meter itself is very high and prohibitive.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the present invention to provide an exposure meter for incident- and reflected-light photometry in which a light receiving section is used interchangeably, with a conventional function held, and other photometric attachments can be mounted and used instead of the light receiving section.
It is another object of the present invention to provide an exposure meter for incident- and reflected-light photometry in which various exposure values can be displayed and a photographer is capable of reading the exposure values directly while looking through a finder.
It is still another object of the present invention to provide an exposure meter for incident- and reflected-light photometry in which a flashlight emitting control device can be loaded, irrespective of relatively low cost, when necessary.
In order to achieve a first object, the exposure meter for incident- and reflected-light photometry of the present invention has, as a unit, a mount section mountable in, or demountable out of, an exposure meter body; a light-receiver raising and lowering mechanism incorporated in the mount section; and a light receiver attached to a movable section of the light-receiver raising and lowering mechanism. In this case, another mount section connectable to the above mount section is constructed in the exposure meter body so that when both the mount sections are connected, the light receiver is aligned with a light receiving element supporting cylinder provided in the exposure meter body. Whereby, an extremely useful exposure meter for incident- and reflected-light photometry can be provided in which adjustment can be made depending on the purpose of photometry and various attachments for photometry can be used for exchange.
According to the present invention, a waterproof member constructed so that the movable section and the light receiving element supporting cylinder are fitted in a watertight fashion is mounted to one of the movable section and the light receiving element supporting cylinder. The light receiver has the shape of a hemisphere of milk white color.
In order to achieve a second object, the exposure meter for incident- and reflected-light photometry of the present invention comprises an incident-light receiving section; a finder optical system for reflected-light photometry including an objective lens and an eyepiece; an arithmetical element for calculating various exposure values on the basis of photometric results obtained by incident- and reflected-light receiving elements; a display window for displaying information on the exposure values obtained by the arithmetical element; a first prism placed in the finder optical system for reflected-light photometry, reflecting incident light passing through the objective lens, even or odd numbers of times, to emerge therefrom; a second prism having an entrance surface opposite to an exit surface of the first prism and reflecting incident light from the first prism, odd or even numbers of times, to emerge toward an eyepiece; and a liquid crystal display device interposed between the first prism and the second prism. Whereby, a very advantageous exposure meter for incident- and reflected-light photometry can be provided in which information on exposure values required for photometry of various modes is displayed on the display window and the liquid crystal display device and can be viewed even in the finder.
According to the present invention, this information on exposure values includes a shutter speed, a stop value, luminance, a luminance difference, and a flashlight component ratio.
According to the present invention, the value of the shutter speed can be displayed, corresponding to a preselected stop value, and the stop value can be displayed, corresponding to a preselected shutter speed.
According to the present invention, the exposure meter is provided with an exposure correcting means in which the amount of correction always used and the amount of correction temporarily used can be set independently of each other.
In order to achieve a third object, the exposure meter for incident- and reflected-light photometry of the present invention has an incident-light photometric section, a finder for reflected-light photometry, a display window for displaying information on exposure values on the basis of photometric results brought about by incident- and reflected-light receiving elements, and a transmitting unit placed to be mountable to, or demountable out of, an exposure meter body, including an arithmetical element which is capable of calculating the total amount of flashlight and ordinary light to display the result on the display window. Whereby, the exposure meter of this type which tends to have a relatively high cost can be provided at a relatively low cost in accordance with a purchaser's desire.
According to the present invention, the transmitting unit and a housing compartment provided in the exposure meter body to house the transmitting unit are designed so that the transmitting unit can be housed in the housing compartment in a specific positional relationship alone. By doing so, an exposure meter for incident- and reflected-light photometry in which the transmitting unit can be loaded rapidly and accurately can be provided.
These and other objects as well as the features and advantages of the present invention will become apparent from th
Bunya Ikuo
Fukazawa Yasushi
Hotta Tetsuo
Kashima Masaharu
Font Frank G.
Nguyen Sang H.
Pillsbury & Winthrop LLP
Seknoic Corporation
LandOfFree
Exposure meter used for photographing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Exposure meter used for photographing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Exposure meter used for photographing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3188340