JPH03244281A - Optical device - Google Patents

Abstract

PURPOSE:To eliminate steam, a rain drop, and dust attached on the outer surface of a transmission filter in a moment by mounting an ultrasonic oscillator on the inner surface of the transmission filter. CONSTITUTION:This device is comprised by fixing two ultrasonic oscillators 4, 5 on the inner surface 2a of the transmission filer 2 with an adhesive, etc. It is desirable to decide the fixing positions of the ultrasonic oscillators 4, 5 in the neighborhood of an optical path L as near as possible to efficiently transmit oscillation to the center part of the light transmission filter 2 at a position not affecting on a video. When the rain drop or the dust, etc., is attached on the outer surface 2b of the transmission filter 2, it can be eliminated by oscillating the light transmission filter 2 according to the oscillation of the ultrasonic oscillator 4, 5 fixed on the inner surface 2a of the transmission filter 2 by turning on a start switch 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical device such as a video camera or an optical distance measuring device using infrared rays.

[Conventional technology]

2. Description of the Related Art In recent years, with the development and commercialization of compact video cameras, vehicle-mounted television cameras, and the like, opportunities for optical devices to be used outdoors have increased significantly. This type of optical device includes
Generally, a light-transmitting filter is provided on the outside of the lens to protect the lens or obtain various photographic effects, but when using an optical device outdoors, it is constantly in contact with the outside air. Water vapor, raindrops, dust, etc. in the atmosphere may adhere to the light-transmitting filter, and the transparency of the light-transmitting filter may deteriorate.
The functionality of the optical device often deteriorates.

A problem arises in that the outer surface of the light-transmitting filter must be cleaned each time with a cloth or the like. As a countermeasure to this problem, conventionally, as shown in FIGS. 9 and 10, the inner surface of the light-transmitting filter 52 located outside the lens 51 is heated by a heating wire 53, and the outer surface 52a of the light-transmitting filter 52 is heated. A method was used to evaporate and remove the water mw attached to the surface.

(Problem to be Solved by the Invention) The conventional method described above is effective at removing fogging from a transparent filter, but it takes a considerable amount of time to remove water droplets, and it is difficult to remove dust. It's impossible. Also,
When heating a heating wire, infrared rays are generated in the optical path.
If this conventional method was used in a distance measuring device that uses infrared rays to measure the distance between objects, it would have adverse effects such as causing the optical device to malfunction, making it unsuitable for use.

(Means for Solving the Problems) In order to solve the above problems, the present invention includes at least one vibrating element attached to one surface of a light-transmitting filter provided outside a lens of an optical device.

[Effect]

In the above method, by vibrating the light-transmitting filter of the optical device, large and small water droplets and dust attached to the outer surface of the light-transmitting filter can be easily removed. This makes it possible to mount the optical device on an optical device without any problem.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing a general video camera, FIG. 2 is a plan view showing a transparent filter section of an optical device according to a first embodiment of the present invention, and FIG. 3 is a longitudinal sectional view thereof.

In the video camera 100 shown in FIG. 1, 1 is glass;
Alternatively, the lens is made of a transparent material such as plastic, and a light-transmitting filter 2 is provided near the outside of the lens 1 as a means for protecting the lens 1 and obtaining various photographic effects. This light transmitting filter 2 is fixed to the inner peripheral surface of a cylindrical case 3, and the lens 1 is in a sealed state within the case 3.

As shown in FIGS. 2 and 3, the optical device according to the first embodiment of the present invention includes an inner surface 2 of the above-mentioned light-transmitting filter 2.
Two ultrasonic transducers 4.5 are fixed to a with adhesive or the like. The fixed position of the ultrasonic transducer 4.5 may be a position that does not affect the image, that is, the outer periphery of the optical path shown by the two-dot chain line in Figs. 2 and 3, but the translucent filter In order to efficiently transmit vibrations to the central part of 2, it is desirable to fix it as close to the optical path as possible. In addition, from the ultrasonic transducer 4.5, the signal cable 6
．． 7 extends, and the through hole 3a provided in the case 3
, 3b, and is wired to, for example, the starting switch 8 in FIG. In the case of an optical device such as an Alevi camera mounted on a vehicle, it can be operated from the driver's seat by connecting a remote control device to the optical device and placing the remote control 14M near the driver's seat.

In the optical device configured as described above, when water droplets or dust adhere to the outer surface 2b of the light-transmitting filter 2, the inner surface 2b of the light-transmitting filter 2 is turned on by turning on the start switch 8.
As the ultrasonic transducer 4.5 fixed to a vibrates, the transparent filter 2 vibrates, making it possible to remove water droplets and dust. At this time, if the phases of the vibrations of the ultrasonic transducers 4 and 5 are synchronized, the amplitude will be doubled, making it easier to remove water droplets and dust.

FIG. 4 is an explanatory diagram showing the phase of vibration of the light transmitting filter 2 in this embodiment, where the vertical axis shows the amplitude and the horizontal axis shows the length of the wavelength.

α in FIG. 4 indicates the phase of vibration of the light-transmitting filter 2 due to the vibration of one ultrasonic transducer 4. In FIG.

Here, points A, B, C, and D are vibration nodes, and no vibration occurs at these parts. Therefore, the transparent filter 2
Water droplets and dust are not removed and remain in a striped pattern in the areas corresponding to the points A, B, C, and D.

Therefore, the ultrasonic transducer 5 is adjusted so that the phase of the vibration of the transparent filter 2 due to the vibration of the other ultrasonic transducer 5 is shifted by 1/4 period from the phase α, as shown by β in FIG. By setting the fixed position and vibrating the two ultrasonic vibrators 4.5 simultaneously or alternately, there are no nodes of vibration, and the entire surface of the transparent filter 2 can be vibrated evenly. It becomes like this.

FIG. 5 is a plan view showing a light transmitting filter portion of an optical device according to a second embodiment of the present invention, and FIG. 6 is a longitudinal sectional view thereof.

Hereinafter, in the description of the configuration, parts that are the same as those in the first embodiment will be given the same numbers, and the description will be omitted.

In FIGS. 5 and 6, reference numeral 11 denotes an annular ultrasonic transducer bonded to the inner surface 2a of the light-transmitting filter 2 with an adhesive or the like, and its inner diameter is equal to the inner surface 2a of the light-transmitting filter 2.
The diameter is larger than the diameter of the optical path at point a. In this case 1
Since the translucent filter 2 is vibrated by two ultrasonic vibrators 11, there is only one type of vibration phase, but a frequency variable device (not shown) can be connected to the ultrasonic vibrator 11 to change the vibration frequency. As a result, there are no nodes of vibration, and the entire surface of the light-transmitting filter 2 can be vibrated evenly.

FIG. 7 is a plan view showing a light transmitting filter section of an optical device according to a third embodiment of the present invention, and FIG. 8 is a longitudinal sectional view thereof. In this third embodiment, a plurality of ultrasonic transducers are scattered around the outer periphery of the optical path on the inner surface 2a of the transparent filter 2. Here, the ultrasonic transducers 21, 22, and 23 are arranged on the same circumference and connected by the same signal cable 27, and are further arranged on the same circumference outside the ultrasonic transducers 21, 22, and 23. Ultrasonic transducers 24, 25, 26 are connected by the same signal cable 28 and arranged. therefore,
Ultrasonic transducers 21, 22, 23 and ultrasonic transducers 24, 2
5.26 at the same frequency, their phases do not overlap and there are no nodes of vibration, so the entire surface of the translucent noirter 2 can be vibrated uniformly. In addition, the signal cable 27 and the signal cable 2
A changeover switch (not shown) is provided between the ultrasonic transducers 21, 22, 23 and the ultrasonic transducers 24, 25, and 26.
By vibrating alternately, it is also possible to prevent the occurrence of nodes of vibration.

〔Effect of the invention〕

As explained above, according to the present invention, water vapor, raindrops, and dust attached to the outer surface of the light-transmitting filter of an optical device can be removed by a simple configuration in which an ultrasonic transducer is attached to the inner surface of the light-transmitting filter. Can be removed instantly. Therefore, it is possible to provide an optical device suitable for outdoor use at a low cost, without having to increase the size of the entire device, and because of its simple configuration, there are fewer failures.

Furthermore, since it is possible to remotely control the ultrasonic transducer, cleaning of the light-transmitting filter of an optical device attached to the rear of the vehicle can also be performed from the driver's seat. Furthermore, since the present invention does not generate infrared rays in the light-transmitting filter portion, the optical device according to the present invention can be applied to optical distance measuring devices that utilize infrared rays, which could not be used in the past.

[Brief explanation of drawings]

1 is a perspective view showing a general video camera, FIG. 2 is a plan view showing a light-transmitting filter section of an optical device according to a first embodiment of the present invention, FIG. 3 is a longitudinal sectional view of the same, and FIG. The figure is an explanatory diagram showing the phase of vibration of the light-transmitting filter section, FIG. 5 is a plan view showing the light-transmitting filter section of the optical device according to the second embodiment of the present invention, and FIG. 6 is a longitudinal cross-sectional view of the same. , FIG. 7 is a plan view showing a light transmitting filter section of an optical device according to a third embodiment of the present invention;
Figure 8 is the same! 9 is a plan view showing a light-transmitting filter section of a conventional optical device, and FIG. 10 is a longitudinal sectional view thereof. 1...Lens, 2...Transparent filter, 4.5.11
゜21.22.23.24,25.26...Ultrasonic vibration f0 Fig. 1 Fig. Fig. Fig. Fig. Fig. 10

Claims (1)

[Claims] 1. An optical device, such as a video camera, which has a lens and is provided with a light-transmitting filter on the outside of the lens, characterized in that at least one vibrating element is attached to one surface of the light-transmitting filter.