JPS6033542A - Photographic lens view angle associated type flash light - Google Patents

Abstract

PURPOSE:To vary automatically and associatively the angle of irradiation of a flash light with the angle of view of a photographic lens by varying the driving voltage to liquid crystal so that the diffused light angle of a diffusion plate using the liquid crystal is coincident with the angle of view of the photographic lens. CONSTITUTION:The liquid crystal 8 sandwiched between glass plates 6 having transparent electrodes 7 is provided onto the front surface of the flash light, and a light source 9 composed of an LED and a photosensor 12 are arrange. Light from a discharge tube is diffused by the liquid crystal 8 into diffused light having an irradiation angle 5, which varies with the liquid-crystal driving voltage 20. For the purpose, the output of a diffusion angle detector 14 for measuring the diffusion angle 21 of the light source 9 is compared by a comparator 17 with the output of a view angle detector 16 for a zoom lens, etc., and the driving voltage is varied on the basis of its output 18 so that the angle of view coincides with the angle 5 of irradiation. Consequently, the angle of view of the lens is varied automatically and associatively with the angle 5 of irradiation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flashlight, and more particularly to an electronic flashlight in which the irradiation angle of the electronic flashlight can be linked to the angle of view of a photographic lens.

Conventionally, this type of electronic flux light has been developed by manually changing the distance between the Fresnel lens 3 and the discharge tube 1 installed in the reflection plate 2, as shown in Fig. The viewing angle and illumination angle 5 were made to correspond. Therefore, when changing the angle of view of the photographic lens, there is a drawback that the distance between the Fresnel lens 3 and the discharge tube 1 must be manually adjusted. In the figure, 4 indicates irradiation light.

The present invention provides means for detecting the angle of view of a photographic lens.

In a diffuser plate using dynamic scattering mode of liquid crystal.

The scattering angle is controlled by changing the driving voltage of the liquid crystal using means for detecting the scattered light by the diffuser plate and detecting the scattering angle, and a comparator for comparing the field angle of the photographing lens and the scattering angle. Particularly, it is an object of the present invention to provide an electronic flashlight in which the above-mentioned drawbacks are solved and the irradiation angle of the electronic flashlight can be automatically linked to match the angle of view of the photographing lens.

Next, an embodiment of the present invention will be described with reference to the drawings.

Referring to FIG. 2, which shows the configuration of an electronic flashlight according to the present invention, one embodiment of the present invention includes a liquid crystal 8 sandwiched between glass plates 6 having transparent electrodes 7;
A light source 9 such as a visible light semiconductor laser or an LED whose optical system is set to output parallel light; a one-dimensional optical sensor 12 that detects scattered light 11 output from the light source 9 and passed through the liquid crystal 8; The scattering angle detector 14 detects the scattering angle 21 from the output 13 of the sensor 12, and the angle of view is detected from the signal 15 containing the angle of view information sent from a photographing lens whose angle of view changes like a zoom lens. An angle of view detector 16, a comparator 17 that compares the outputs of the scattering angle detector 14 and the angle of view detector 16, and a liquid crystal drive voltage generator 19 that generates a drive voltage 20 for the liquid crystal 8 based on the output 18 of the comparator 17. including.

The light generated by the discharge tube 1 is emitted as parallel light by the reflecting plate 2, but by applying a voltage to the liquid crystal 8, the liquid crystal 8 enters a dynamic scattering mode and scatters the emitted light.

Generates an illumination angle of 5. The irradiation angle 5 changes depending on the liquid crystal drive voltage 20 and matches the scattering angle 21 of the scattered light 11, so the output of the scattering angle detector 14 which measures the scattering angle 21 from the output 13 of the -dimensional optical sensor 12 and the % angle of view A comparator 17 compares a signal 15 containing information with the output of a view angle detector 16 that measures the view angle, and a drive voltage is generated by a liquid crystal drive voltage generator 19 so that the view angle and illumination angle 5 match based on the output 18. Generate 20. The irradiation angle is controlled and linked to match the angle of view by this drive voltage 20.

As explained above, the present invention includes a means for detecting the angle of view of a photographic lens, a means for detecting the scattered light by the diffuser plate in a diffuser plate using a dynamic scattering mode of a liquid crystal, and detecting the scattering angle. The scattering angle can be controlled by changing the driving voltage of the liquid crystal using a comparator that compares the field angle of the photographing lens with the scattering angle. This control has the effect of automatically linking the irradiation angle of the electronic flashlight with the angle of view of the photographic lens.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a light emitting section of an electronic 7 rack light, and FIG. 2 is a block diagram of an embodiment of the present invention. 1...Discharge tube, 2...Reflector, 3...
...Fresnel lens%4...Irradiation light,5.
...Irradiation angle, 6...Glass plate%7...
...Transparent electrode, 8...Liquid crystal, 9...
Parallel light source, 10... Tsuboyuki light, 11...
...scattered light, 12...-dimensional light sensor, 13.
...Signal containing scattering angle information, 14...Scattering angle detector% 15...Signal containing view angle information%
16... View angle detector, 17... Comparator, 18... Comparison result signal, 19...
Liquid crystal driving voltage generator, 20...Liquid crystal driving voltage%
21...Scattering angle. 5-

Claims (1)

[Claims] means for detecting the angle of view of the photographic lens; means for detecting the scattered light by the diffuser in a diffusion plate using a dynamic scattering mode of liquid crystal to detect the scattering angle; and means for detecting the angle of view of the photographic lens and the scattering and a means for matching the angle of view and the scattering angle by controlling the drive voltage of the liquid crystal using the output of the comparator, and adjusting the irradiation angle of the flashlight. A flashlight linked to the angle of view of the photographing lens, which is linked to the angle of view of the photographic lens.
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