JPH03132735A - Electronic flash emitting device - Google Patents

Abstract

PURPOSE:To photograph different distant objects on the same screen with a proper exposure by juxtaposing plural reflectors along the longitudinal direction of a xenon tube making these reflectors independent, thereby varying light distribution width. CONSTITUTION:A first reflector 1 and a second reflector 2 are juxtaposed so as to enclose the xenon tube 3 except its front surface and along its longitudinal direction. The top parts of planer bimorphs 4 and 5 whose one end parts are fixed are fixed on both up and down parts of back surface side of the first reflector 1, and support the first reflectors 1. These bimorphs 4 and 5 are deformed when a voltage is applied. The second reflector 2 is supported by bimorphs 6 and 7 the same as the first reflector 1. With respect to two short and long distant objects, the light distribution of two reflectors are individually adjusted, so that proper light is projected on the objects of short and long distances.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electronic flash light emitting device that is built into a camera or detachably attached to a camera body, and specifically relates to an electronic flash light emitting device that is built into a camera or detachably attached to a camera body. This invention relates to an electronic flash light emitting device that makes light variable.

[Prior art 1 This type of conventional electronic flash light emitting device is disclosed in Japanese Patent Application Laid-Open No. 50-83
As shown in No. 018, there is a system with two xenon tubes, as shown in Japanese Utility Model Application No. 54-92739, a system that deforms the reflective shade, and as shown in Japanese Patent Application Laid-Open No. 53-97819. , a system in which the temperature is changed using a liquid crystal, and a system in which a large number of protectors are arranged in front of the xenon tube as shown in Japanese Utility Model Application No. 53-32023 have been proposed.

[Problems to be Solved by the Invention] However, in such conventional electronic flash light emitting devices, the overall light distribution is widened and the guide number (toward GN) is lowered, or vice versa. For example, in the case of a person, if the person is alone or gathered in one place, it is possible to distribute the light evenly over the subject, but
As shown in the figure, two people are separated on the left and right sides of the screen,
Furthermore, if the person is far away from the front and back, depending on the method of the camera's distance measuring device, for example, if one subject (the subject in the foreground in Figure 7) is determined to be the main subject, the center of that person will be properly exposed. However, there was a problem in that the other subject (the rear subject in FIG. 7) was under-photographed.

In addition, methods that have two xenon tubes, multiple protectors, and methods that use liquid crystals have the disadvantage that the entire device becomes large, making it difficult to make it compact in terms of mounting on the camera body, and making it more expensive. was there.

An object of the present invention is to provide an electronic flash light emitting device that can properly illuminate a plurality of subjects regardless of their positions.

[Means for Solving the Problems] The gist of the present invention to achieve the object is to arrange a plurality of reflective shades in parallel along the length direction of a xenon tube, and to independently connect these reflective shades. An electronic flash light emitting device characterized by being able to vary the width and narrowness of light distribution.

[Function] The electronic flash light emitting device configured as described above reduces the guide number (by widening the light distribution of the reflective shade corresponding to a nearby subject) for multiple subjects (and reducing the guide number of the reflective shade corresponding to a distant subject). By narrowing the light distribution of the shade, the guide number can be increased, allowing appropriate light to be applied to subjects at near and far positions.

[Example] Example 1 FIGS. 1 to 6 show Example 1 of an electronic flash light emitting device according to the present invention, and this example is built into a camera body as shown in FIG.

In FIG. 6, 10 is a camera body, 12 is a finder, 13 is a lens barrel, 14 is a photographing lens, 15 is a release button, and 11 is a protector for an electronic flash device. The reflective shade, xenon tube, etc. of the electronic flash light emitting device of this embodiment are accommodated.

In Fig. 1, numeral 3 is a xenon tube, and two reflective shades, a first reflective shade 1 and a second reflective shade 2, are arranged side by side along its length so as to surround the xenon tube 1 except for the front side. has been done. The first reflective shade 1 and the second reflective shade 2 are formed into concave shapes by flexibly and elastically deformable plate materials.

4.5 is a plate-shaped bimorph whose one end is fixed to the camera body corresponding to the first reflective shade 1, and whose tips are fixed to both upper and lower ends on the back side of the first reflective shade. , supporting the first reflective shade 1. These bimorphs4.
5 deforms by applying a voltage, as described in Japanese Patent Application Laid-Open No. 63-237044. The parts are deformed. When the voltage application is stopped, the reflective shade returns to its original shape due to its own elastic restoring force.

Furthermore, the second reflective shade 2 is also supported by the bimorph 6.7 in the same way as the first reflective shade 1.

The power supply control to bimorphs 4 and 5 and the power supply control to bimorphs 6 and 7 are performed separately. For example, as shown in Fig. When the subject is located on the left side of the screen, the opening width of the reflective shade (vertical length) in normal conditions
When i is shown in Figure 2, a voltage is applied to the bimorph 6.7 of the second reflective shade 2 corresponding to the subject on the right side of the screen, and the aperture width is changed as shown in Figure 3. By narrowing it down to ゛, the flash light has a wide light distribution ((the reflection angle of the flash reflected by the reflector 2 with respect to the optical axis, that is, the aperture angle is wide (
), the guide number will become smaller. In addition, by leaving the first reflective shade 1 corresponding to the subject on the left as it is, the light distribution and guide number are narrower (the flash reaches farther) than the second reflective shade 2. The modification is shown in FIG.

Therefore, as shown in FIG. 5, both wave objects are properly exposed.

Then, when the photographing is completed, the electricity to the bimorph is cut off, and the reflective shade returns to the position of the opening width °C by its own elastic restoring force.

The photographer may manually energize bimorphs 4 and 5 and bimorphs 6 and 7 depending on the subject distance information, etc., but distance measurement information etc. from a distance measurement circuit built into the camera body etc. It is also possible to do so depending on the In this case, it is desirable to use a wide-field range finder as the range finder. This wide-field distance measuring device was published in Japanese Patent Application Laid-Open No. 61-24672.
As disclosed in No. 5, it measures the surrounding areas other than the center of the finder and uses a predetermined algorithm to focus on the assumed subject. In the case of Fig. 5, both the left and right The position of the wave object can be measured, and based on this distance measurement information, the bimorphs 4 and 5 can be energized, and the bimorphs 6 and 7 can be energized.

By the way, in the case of Fig. 5, it is possible to obtain the appropriate exposure for a distant subject located on the left side of the screen.
Because the light distribution is narrow, not much light reaches the area around the screen, as shown by the diagonal lines.

To prevent this phenomenon, depending on the position of the subject, only one of the upper and lower bimorphs is driven and the reflective shade is deformed accordingly, allowing light to reach the corners of the screen.

In addition, in this example, the reflective shade is deformed according to the subject distance,
Because it is possible to change the light distribution and guide number,
Needless to say, this method is also effective for cameras with variable focal lengths.

Example 2 FIG. 8 is a front view showing the second embodiment.

The first embodiment described above shows an example in which the reflective shade is divided into two parts, but this example is an example in which the reflective shade is divided into three parts, 21 is a xenon tube, 22, 23, 24 are divided reflective shades, 25.
26, 27, 28, 29, and 30 are bimorphs fixed in the same manner as in Example 1 of each reflective shade.

In this embodiment, as in the first embodiment, the bimorphs of each reflective shade can be driven independently based on distance measurement information from a wide-field distance measurement device.

Figure 9 is a photograph that combines the reflective shade and wide-field distance measurement shown in Figure 8. Based on the information from S wide-field distance measurement, the subject distances on both sides of the center are calculated, and 3 Figure 3 shows the three reflective shade shades 22, 23, and 24 (photographed by independently contracting and expanding them).

Example 3 FIG. 1O is a perspective view showing the third embodiment.

In both Examples 1 and 2 described above, the light distribution and guide number are changed by deforming the divided reflective shade, but in this example, the light distribution and guide number are changed by sliding the divided reflective shade in the front and back direction. I am trying to change the light and guide number.

31 is a xenon tube, 32.33 is a reflective shade divided into parts, 34.35 is a xenon tube fixing frame, the frame 34.35 is fixed to the camera body, and both ends of the xenon tube 31 are attached to the frame 34.35. It passes through holes 34a and 34b formed in the holes 34a and 34b. Reference numerals 36 and 37 denote slide plates each having a reflective shade 32 and 33 fixed to its tip. One slide plate 36 has two long grooves 36b spaced apart in the front and rear direction.
36c are formed, and by fitting shafts 38 and 39 implanted in the camera body into these long grooves 36b and 36c, it is possible to slide in the front and back direction shown by arrow A. Also, the other slide plate 37 also has one slide plate 36.
It is configured in the same manner as the above, and is slidable in the front and back direction shown by arrow B. Gear parts 36a and 37a are formed on the side surfaces of the slide plates 36 and 37, and mesh with the binion gears 41 and 43 of the respective drive motors 40 and 42, respectively.

Therefore, by rotating the motors 40, 42,
Each slide plate 36, 37 slides independently, the distance between each divided reflective shade 32, 33 and the xenon tube changes, and the light distribution and guide number change, resulting in the same effect as in Example 1. will be obtained.

[Effects of the Invention] As explained above, according to the present invention, the light distribution of the flash can be adjusted by dividing the reflective shade and making each reflective shade independently deformable and movable in the front and rear directions. This change in light distribution will also change the guide number, allowing you to photograph subjects at different distances within the same screen with proper exposure, changing the light distribution and guide number to match the variable focus camera, and furthermore. It is compact and can be constructed at low cost.

[Brief explanation of the drawing]

Fig. 1 is a front view showing Embodiment 1 of the flashlight emitting device according to the present invention, Fig. 2 is a sectional view showing the normal state, Fig. 3 is a sectional view showing the state where the aperture width is narrowed, and Fig. 4 is the used one. 5 is a cross-sectional view showing a photographing state; FIG. 6 is a perspective view of a camera that can effectively implement the present invention; FIG. 7 is a diagram showing a photographing state using a conventional electronic flash device; Figure 8 shows Example 2.
Fig. 9 is a front view showing the photographing state, Fig. 10 is a front view showing the
The figure is a perspective view showing Example 3. 2: Reflective shade xenon tube 5.6.7: Bimorph 23.24: Reflective shade 26.27.28.29.30: Bimorph 33: Reflective shade 37: Slide plate 42: Motor 42: Binion gear. Figure 1 Figure 2 Figure 5 Figure 6

Claims (1)

[Claims] 1. An electronic flash characterized in that a plurality of reflective shades are arranged in parallel along the length direction of a xenon tube, and the width and narrowness of the light distribution of these reflective shades can be varied independently. Light emitting device. 2. An electronic flashlight emitting device, wherein the reflective shade according to claim 1 is configured to have a variable reflection angle. 3. An electronic flashlight emitting device, wherein the reflective shade according to claim 1 is configured to be movable in the front and rear directions with respect to the xenon tube.