JP3407089B2 - Portable light meter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable light meter for measuring the amount of illuminance light on a subject surface which is convenient for carrying.

[0002]

2. Description of the Related Art A large exposure meter or a small exposure meter that is convenient for carrying is generally used as an exposure meter for measuring the brightness of an object and surroundings. Are commercially available. This portable exposure meter is generally a semi-transparent flat plate having a light diffusing property for controlling the incident amount (light distribution amount) of light rays at the measurement position of the exposure meter main body, that is, the front position of the light receiving element that converts the light amount into an electric amount. Or a hemispherical light receiving plate must be arranged. There are several types of light receiving plates, such as those with different shapes and different light transmittance.When the photographer decides the exposure, a specific light receiving plate is placed at the measurement position of the exposure meter depending on the shooting conditions and the brightness is adjusted. Is being measured. Therefore, it is necessary to always carry such a plurality of light receiving plates without storing means.

[0003]

However, it is bulky and troublesome to carry many types of light receiving plates. Also, since only a single light-receiving plate is placed at the measurement position during measurement, it is necessary to consider the storage location of other light-receiving plates as well, and the surface of the light-receiving plate should be kept clean when storing it in a storage bag such as a jacket pocket. It might hurt. Further, in the case where a hemispherical light receiving plate (light bulb) is fixed, the hemispherical portion protrudes from the exposure meter main body, which is an obstacle to carrying. In particular, there is a risk that the surface may be damaged when it is stored in a portable soft case. With such an exposure meter with a light-receiving plate protruding from the surface, it becomes an obstacle when carrying it, storing it in a pocket or storing it in a carrying case, and in the case of a carrying case, it causes friction between the case and the surface of the receiving plate. Therefore, the surface is often damaged, and therefore, the surface is easily damaged, and when the surface is damaged, it affects the amount of incident light received, making accurate measurement difficult. An object of the present invention is to provide a portable exposure meter that does not require a separate storage bag when carrying two types of light receiving plates, a flat plate type and a hemispherical type. Another purpose is to provide a portable light meter that can be stored in a box body so that it does not damage the surface of the projected light bulb when it is stored in a carrying case, which is convenient for carrying. is there.

[0004]

The above object of the present invention can be achieved by the following constitution. The configuration is such that it has a built-in light receiving element that receives the amount of emitted light and converts it into an amount of electricity, arranges a light diffusing light receiving plate in the light incident path of this light receiving element, and displays the measured values converted by the light receiving element. In a portable light meter consisting of a box with a display unit that does not project from the surface of the box by burying the protruding portion of the light-receiving plate placed at the measurement position when being carried or in the non-measuring state inside the box. It is characterized by having done. According to the present invention, a light-receiving element that receives the amount of irradiation light and converts it into an electric quantity is built in, and a light-receiving plate composed of a light-transmissive light diffusing plate is arranged in the light incident path of this light-receiving element and converted by the light-receiving element. In a portable light meter consisting of a box with a display for displaying measured values, a configuration is provided in which a light receiving plate with different light distribution characteristics is stored in the same box separately from the light receiving plate placed at the measurement position. Thus, the above-mentioned object can be achieved.

[0005]

In the portable light meter of the present invention, the light receiving plate which is arranged in a protruding manner can be housed inside the box of the light meter body when not being measured or when it is carried. The surface of the light receiving plate is not damaged when it is stored in the case, and it is possible to accurately measure the ambient irradiation light for a long period of time. Therefore, a photo of proper exposure is always obtained. Moreover, since there is no protruding portion, it can be easily stored when the exposure meter body is stored in a carrying case or in a pocket such as a jacket. As a fixing method for fixing the hemispherical light receiving plate to the main body of the present invention, it is easy by providing a protruding piece on the lower edge of the light receiving plate and adopting a screw groove method, a pressing method in which an elastic member is arranged, or a bayonet method that can be easily removed. It can be easily attached and detached, and since it has no protruding part on the surface of the main body, it can be easily stored in a portable soft case.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a portable light meter of the present invention is shown in the drawings. FIG. 1 is a perspective view of an embodiment of a portable light meter of the present invention. FIG. 2 is an enlarged XX cross-sectional view of a state where the light receiving plate is stored in the storage portion of this embodiment. FIG. 3 is a side view of the housing in the carrying case. FIG. 4 is a side view showing a storage state of a conventional exposure meter. FIG. 5 is a plan view of a second embodiment of the portable light meter of the present invention. FIG. 6 is an enlarged YY sectional view showing the housed state of the light receiving plate of the second embodiment.

Reference numeral 1 denotes a main body formed of a box body arranged at a measuring position by a detaching mechanism such as screwing a flat or hemispherical light receiving plate 2, and a light receiving element 3 is arranged inside the light receiving plate 2. The light receiving element 3 is composed of a photoelectric tube, a photoelectric semiconductor, etc., and converts the incident light quantity into a current value and a voltage value. The converted measured values are displayed on the display plate 4 formed of a liquid crystal plate or the like on the side surface of the main body 1 by analog display or digital display. Reference numeral 5 denotes an accommodating portion provided with an engaging portion 6 capable of accommodating the hemispherical portion after the light receiving plate 2 is removed from the main body 1. The engaging portion 6 is provided with a screw groove or a bayonet type groove. A groove that engages with the engaging portion 6 is provided on the peripheral edge of the light receiving plate 2. Reference numeral 7 is an elastic member such as a rubber or a rubber which comes into contact with the lower edge 2a of the light receiving plate 2. Reference numeral 8 is a locking groove that engages with a locking piece 2b provided on the lower end edge 2a of the light receiving plate 2, and 9 is a carrying case. Reference numeral 10 denotes a projecting piece provided on the lower end edge 2a of the light receiving plate. The projecting piece 10 is formed so as to engage with a rack groove 11a of a guide member 11 that slides and guides the light receiving plate 2. The guide member 11 is always provided. The light receiving plate 2 is elastically biased toward the center.

A portable light meter of the present invention will be described based on an embodiment shown in the drawings. When measuring the amount of light
As shown in FIG. 3, the flat light receiving plate 2 is screwed and fixed to the fitting portion 2 a on the upper surface of the light receiving element 3. On the other hand, hemispherical light receiving plate 2
Is stored in the storage portion 5 with the hemispherical portion inside. Now, in the measurement, the exposure meter main body 1 is gripped, the light receiving plate 2 is arranged on the incident surface of the subject to measure the amount of light to the subject, and further the amount of light reflected from the subject is measured. Based on these values, the exposure amount such as the aperture value and the exposure time (shutter open time) is determined based on the digital value displayed on the display plate 4. The measured value is visually recognized on the display board 4. If the measuring unit including the light receiving plate 2 and the light receiving element 3 is rotatably formed as shown in FIG. 5, the incident position of the light receiving plate 2 can be arbitrarily changed during measurement. If necessary, the flat light-receiving plate 2 storage portion 5 at the measurement position is replaced with the hemispherical light-receiving plate 2 stored therein, and the flat light-receiving plate 2 is stored in the storage portion 5. By selectively arranging the light receiving plates having different shapes, the light distribution characteristics are changed and measured, and the exposure amount is determined. When the exposure meter is housed in the carrying case 9 after such exposure measurement is completed, before the body 1 is housed in the carrying case 9, as shown in FIG. And the hemispherical light receiving plate 2 is housed in the housing part 5 with the hemispherical part facing down. The light receiving plate 2 can be housed in the housing part 5 by rotating to engage the engaging part 6 with the groove of the light receiving plate 2. Next, as shown in FIG. 3, the main body 1 is placed in the carrying case 9. At this time, since the light receiving plate 2 is buried in the main body 1, it can be easily stored. Therefore, it does not get in the way when it is stored in a pocket such as a jacket.

The light receiving plate 2 of the second embodiment as shown in FIG.
According to this, for example, the engagement between the locking piece 2b of the light receiving plate 2 and the locking groove 8 provided in the main body 1 is released to resist the elasticity of the elastic member having the apex of the hemispherical light receiving plate 2. And press it with your finger,
The light receiving plate 2 is pushed by being pushed inside the main body 1 and is rotated.
Can be stored completely. Further, as shown in FIG. 6, the light receiving plate 2 is pushed inside the guide member 11 and is pushed down along the guide member 11 against the elastic force of the elastic member 7 that abuts against the lower edge 2a of the light receiving plate 2, The projecting piece 10 provided on the outer side of the lower end edge 2a of the above is engaged with the rack groove 11a of the guide member 11. By engaging the rack groove 11a at the lowest position, the light receiving plate 2 can be completely stored.

The location where the light receiving plate 2 is housed in this way may be the location where the measuring unit of the light receiving plate 2 is installed. Alternatively, if it is set to another location, the light receiving plate 2 is removed from the installation site and the housing unit 5 is installed.
To fit. The storage portion 5 may be a place near the display plate 4 or the back side. It suffices that the protruding portion of the light receiving plate 2 be housed in the main body 1 when the main body 1 of the exposure meter is stored in the carrying case 9. When measuring the amount of light,
Take out the exposure meter main body 1 from the carrying case 9 and receive the light receiving plate 2
Are placed in place. For example, according to the first embodiment, the light receiving plate 2 of the storage portion 5 is rotated to disengage the engaging portion 6,
The light receiving plate 2 is fitted in the measurement position. According to the second embodiment, the guide member 11 is moved outward while being expanded, and the projecting piece 10 is separated from the rack groove 11a, and the elastic force of the elastic member 7 causes the lower end edge 2a of the light receiving plate 2 to move. Will be pushed up and placed at the measurement position.

[0011]

According to the portable exposure meter of the present invention, two types of light receiving plates having different light distribution characteristics can be stored in a single exposure meter, and it is not necessary to separately prepare a storage bag. Therefore, there is no possibility of damaging the surface of the light receiving plate. Further, since the hemispherical projecting portion that projects during non-measurement and during carrying can be housed in the box body, it can be easily housed in the carrying case. Moreover, since it is possible to prevent the surface of the light receiving plate from being damaged, it is possible to accurately measure the amount of light over a long period of time.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a portable light meter of the present invention.

FIG. 2 is an enlarged XX cross-sectional view of the storage section of this embodiment.

FIG. 3 is a side view showing a state where the portable light meter is stored in a portable case.

FIG. 4 is a side view of a conventional exposure meter.

FIG. 5 is a front view showing a second embodiment of the portable light meter of the present invention.

FIG. 6 is an enlarged YY cross-sectional view of a main part showing a housed state of a light receiving plate according to a second embodiment.

[Explanation of symbols]

1 ... Main body 2 ... Light receiving plate 3 ... Light receiving element 4 ... Display board 5 ... Storage 6 ... Engagement part 7 ... Elastic member 8 ... Locking groove 9… Carrying case 10 ... Protrusion 11 ... Guiding member

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Claims (4)

(57) [Claims] 1. A light receiving element which receives an amount of irradiation light and converts it into an electric quantity is built in, a light diffusing light receiving plate is arranged in a light incident path of the light receiving element, and a measured value converted by the light receiving element is arranged. In a portable light meter consisting of a box with a display unit for displaying, the protruding portion of the light receiving plate placed at the measurement position when being carried or in the non-measurement state is embedded in the box body and does not project from the box surface. A portable light meter characterized by doing so. 2. The light receiving plate arranged in the box is pushed outward from the inside by an elastic member, the light receiving plate is positioned at a measurement position during measurement, and resists the urging force of the elastic member during non-measurement. 2. The portable exposure meter according to claim 1, further comprising: an engaging portion that is pushed down to form a housing for housing the light receiving plate in the box body and that maintains the housing state. 3. The light receiving plate removably attached to the box body corresponding to the light incident position of the light receiving element can be removed from the fixed position when not measuring and can be stored in a storage portion provided in a part of the box body. The portable light meter according to claim 1, characterized in that. 4. When the flat light-receiving plate is fixed to the measuring position during measurement, the other hemispherical light-receiving plate is fitted into the housing portion inside the box body, and the hemispherical protruding portion is inside the box body. 4. The portable exposure meter according to claim 1, wherein the flat light receiving plate can be housed in the housing when the hemispherical light receiving plate is housed and is fixed at the measurement position.