JP3478841B2 - Night vision device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a night-vision device used for observing and photographing a nocturnal animal.

[0002]

2. Description of the Related Art As shown in FIG. 13, a conventional night-vision apparatus includes a main body 1, an objective lens 2 for condensing weak light on an image pickup surface, and an image intensifier (image intensifying tube) for multiplying the weak light. , I.I) 3 and an eyepiece lens 4,
It has a function of operating a built-in dry battery (not shown) to image the subject 5 in the dark.

The objective lens 2 is composed of a CCTV, ITV lens or the like, and is detachably mounted on an objective lens mount (not shown) on the front part of the main body 1.

The image intensifier 3 is also used.
Is a fiber plate 30 which is composed of a bundle of a large number of optical fibers and which divides an optical image of the subject 5 that has passed through the objective lens 2 into pixels and transmits it, and an optical image formed on the back surface of the fiber plate 30. A photocathode 31 for converting an image into an electron image, an MCP (microchannel plate) 32 for multiplying the converted electron image, and a fluorescent screen 33 disposed behind the MCP 32 for converting the electron image into an optical image again.
And a fiber plate 30A which is disposed behind the fluorescent screen 33 and which divides an object image converted into an optical image into pixels and transmits the pixels, and is incorporated inside the main body 1.

The eyepiece 4 is detachably attached to an eyepiece mount (not shown) at the rear of the main body 1 and has a function of projecting visible light to the photographer's eyes.

Therefore, in order to image the subject 5 in the dark, a switch (not shown) is turned on and the subject 5 in the dark is imaged.
The objective lens 2 may be directed to. Then, the weak light of the subject 5 is incident on the objective lens 2 to form an image, and the optical image of the subject 5 is divided into pixels by the fiber plate 30 and the photocathode 3 is formed.
1, and converts the optical image formed by the photocathode 31 into an electronic image.

The converted electronic image is MCP3
It is electron-multiplied to 2, and the fluorescent screen 33 converts the electron-multiplied electron image into an optical image again. However, the re-converted optical image of the subject 5 is transmitted from the fiber plate 30A to the eyepiece 4 to be imaged, and is observed by the photographer.

By the way, in order to image the subject 5 in the darkness by using the conventional night-vision device, it is necessary to have a brightness of about starlight, and the brightness of about starlight is lost and the subject 5 becomes dark. Then, the light itself that is incident on the image intensifier 3 from the subject 5 is reduced. In this case, the light can be detected by the image intensifier 3, but the subject 5 cannot be identified. That is,
Even with a night-vision device, a finite amount of light is required to identify the subject 5.

As a method of eliminating the adverse effect when the amount of light necessary for identifying the subject 5 is insufficient, the subject 5
Although a method of illuminating the subject with a floodlight is generally considered, the illumination of the subject 5 is not a preferable method for the purpose of night vision. Therefore, the subject 5 is illuminated by an invisible light projector (infrared illumination, infrared LED, infrared LD, etc.) that is invisible to the human eye.
Has been adopted.

Incidentally, as a prior art document of this kind, the actual exploitation 5
For example, there is a 4-92162 publication.

[0011]

The conventional night-vision device is constructed as described above, and when the amount of light necessary for identifying the subject 5 is insufficient, a method of illuminating the subject 5 with an invisible light projector is adopted. However, since the projector is configured as a unit separate from the night vision device, the operability was extremely poor.
Therefore, conventional floodlights have only been used in stationary night vision systems.

The present invention has been made in view of the above, and an object thereof is to provide a night-vision device which can remarkably improve the operability of the projector.

[0013]

In the present invention, in order to achieve the above-mentioned object, a plurality of light sources for irradiating a subject with infrared rays and a photoelectric device for converting an optical image of the subject formed by an objective lens into an electronic image. Surface, a fluorescent screen that converts an electronic image into an optical image, an eyepiece lens that projects the optical image displayed on the fluorescent screen into the photographer's eyes, and a plurality of light sources are sequentially blinked to make electrons of the electronic image incident. A light source drive circuit that continuously emits light from the associated phosphor screen is provided, and infrared rays emitted from a plurality of light sources are characterized in that their respective irradiation ranges partially overlap with each other.

In order to achieve the above-mentioned object, the present invention is characterized in that the light source drive circuit overlaps the irradiation timings of a plurality of light sources for the afterimage time of the phosphor screen having the afterimage characteristic.

[0015]

According to the present invention, since a plurality of light sources are integrally embedded in the main body, operability and maneuverability can be improved, and the brightness of a starlight level is lost, and the subject becomes dark. However, it is possible to prevent a decrease in the amount of light that is incident on the image intensifier from the subject and improve the performance of the high-sensitivity night-vision device.

When infrared rays are emitted from the first light source, if the infrared rays to be emitted have uneven light quantity, it becomes difficult to clearly grasp the subject in the portion where the uneven light quantity occurs. On the other hand, in the present invention, a plurality of light sources are provided, and the infrared rays emitted from the plurality of light sources have their respective irradiation ranges partially overlapping with each other. Therefore, since the unevenness of the light amount is canceled by the infrared rays, the subject can be clearly recognized even in the dark.

However, if a plurality of light sources are provided and all of them are continuously turned on, much more electric power is required than when one light source is provided. In this respect, in the present invention, the plurality of light sources are made to blink sequentially, so that the power consumption can be reduced.

Furthermore, according to the present invention, the lighting of one light source and the other one of the light sources overlap in a time-sharing manner for the afterimage time of the fluorescent screen, so that the fluorescent screen is displayed despite the afterimage characteristic of the fluorescent screen. In other words, it becomes possible to recognize the flashing of the plurality of light sources as continuous continuous light.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an embodiment shown in FIGS. The night-vision device according to the present invention includes a compact main body 1, an objective lens 2, an image intensifier (also called an image intensifier tube, II) 3, an eyepiece 4, and an infrared light emitting diode (light source). 6.6A / 6B
And a light source drive circuit 7, and has a function of operating a plurality of built-in dry batteries to image the subject 5 in the dark.

As shown in FIGS. 1 to 3, the objective lens 2 is composed of a CCTV or ITV lens and the like, and is detachably mounted on an objective lens mount (not shown) in the front part of the main body 1. ing.

Further, the above image intensifier 3
As shown in FIG. 6, a fiber plate 30 which is composed of a bundle of a large number of optical fibers and which divides an optical image of the subject 5 that has passed through the objective lens 2 into pixels and transmits it, and is provided on the back surface of the fiber plate 30. Photoelectric surface 31 for converting the formed optical image into an electronic image, MCP (multiplier part) 32 for multiplying the converted electronic image, and MCP 3 having afterimage characteristics
2, a fluorescent screen 33 arranged to convert the electronic image into an optical image again, and a fiber plate arranged behind the fluorescent screen 33 to divide the subject image converted into the optical image into pixels for transmission. 30A and is built in the main body 1.

The eyepiece 4 is shown in FIGS.
As shown in FIG. 1 and the like, it is detachably attached to an eyepiece mount (not shown) at the rear of the main body 1 and has a function of projecting visible light to the photographer's eyes.

On the other hand, the infrared light emitting diode 6, 6A,
The 6B (infrared LED) has a function of irradiating infrared light to eliminate the shortage of the light amount of the subject 5 in the dark, but as shown in FIG. Instead, three are arranged in a triangle and buried.

That is, when a single infrared light emitting diode 6 is turned on and infrared light is irradiated to the image pickup center of the subject 5, the irradiation illuminance distribution of the infrared light emitting diode is divided and displayed on the X and Y axes. As shown in FIG. 7, unevenness in the light amount (irradiation unevenness) inevitably occurs at the image pickup center of the subject 5 due to the characteristics of the light emitting diode 6, and thus even if the subject 5 having the uneven light amount is night-visioned, it is an extremely unsightly image. Inevitably.

On the other hand, a plurality of infrared light emitting diodes 6
Infrared light emitting diodes can be obtained by using 6A and 6B to irradiate infrared light in the vicinity of the imaging center of the subject 5 and to partially overlap the plurality of infrared lights at the imaging center of the subject 5. As shown in FIG. 8 in which the distribution of the illumination illuminance is divided into the X and Y axes and displayed, the infrared light in the overlapping portion cancels out the unevenness of the light amount with each other. It is possible to prevent unevenness in the amount of light from occurring at the center of the image pickup.

In view of the above, in the present invention, a plurality of infrared light emitting diodes 6, 6A, 6B are used to irradiate infrared light in the vicinity of the imaging center of the subject 5 to prevent uneven irradiation. I have to.

As shown in FIG. 9, the light source driving circuit 7 further includes a dry battery 70, a plurality of lighting switches 71 for closing a plurality of infrared light emitting diodes 6, 6A, 6B by closing a circuit, and a voltage difference. Switch drivers 7 for opening and closing the plurality of lighting switches 71 by using
2, a shift register 73 for sequentially turning on a plurality of lighting switches 71, and a timing generator 74 for generating a timing of a series of sequences. In consideration of the following reasons, a plurality of infrared light emitting diodes 6, 6A are provided.・ 6
It has a function of sequentially blinking B with a clock signal.

That is, a plurality of infrared light emitting diodes 6, 6A
6B is turned on by using the dry battery 70 as a power source, but if all are turned on together, the dry battery 70 will be significantly consumed.
Therefore, in the present invention, in view of the above, the light source drive circuit 7
The plurality of infrared light emitting diodes 6, 6A, 6B are sequentially blinked at the timing shown in FIG. 10, and any one of the plurality of infrared light emitting diodes 6, 6A, 6B is turned on to minimize the consumption of the dry battery 70. I try to suppress it to the limit.

In FIG. 10, the infrared light emitting diodes 6 and 6 are shown.
A and 6B are represented by LED1, LED2, ....

Further, in consideration of the following reason, the light source drive circuit 7 turns on the infrared light emitting diode 6A immediately before the infrared light emitting diode 6 is turned off, and the irradiation timing of the plurality of infrared light emitting diodes 6, 6A, 6B. Are overlapped by the afterimage time of the phosphor screen 33 having the afterimage characteristic.

That is, a plurality of infrared light emitting diodes 6 ・ 6A
6B is turned on or off with almost no delay when the plurality of lighting switches 71 are opened or closed, but since 6B has afterimage characteristics with respect to the pulse response incident light that turns on or off the phosphor screen 33, When the light is turned off, an afterimage as shown by an arrow in FIG. 11 occurs.

Therefore, a plurality of infrared light emitting diodes 6
In order to observe the light emission of the fluorescent screen 33 based on the lighting of 6A and 6B as continuous light, it is indispensable to cancel the afterimage characteristic of the fluorescent screen 33.

In view of the above, in the present invention, for example, the infrared light emitting diode 6 (LED-in FIG. 12) is used.
1) and infrared light emitting diode 6A (LED in FIG. 12)
As shown in the timing of FIG. 12, the lighting of -2) is made to overlap by Δt time (afterimage time of the phosphor screen 33) in time division so that the phosphor screen 33 emits light continuously. .

Therefore, to image the dark subject 5,
A plurality of infrared light emitting diodes 6, 6A, 6B may be sequentially blinked by turning on a switch (not shown), and the objective lens 2 may be directed to the subject 5.

Then, since the infrared light sequentially radiated near the periphery of the image pickup center of the subject 5 partially overlaps each other at the image pickup center and cancels out the uneven light amount, the subject is irrespective of the characteristics of the light emitting diode. It is possible to prevent unevenness in the amount of light from occurring in the image pickup center of 5, and it is possible to clearly grasp the subject 5 even in the dark.

Then, the infrared light reflected by the subject 5 is incident on the objective lens 2 to form an image, and the optical image of the subject 5 is divided into pixels by the fiber plate 30 and transmitted to the photocathode 31. The optical image formed by 31 is converted into an electronic image.

The converted electronic image is MCP3
The electron image is electron-multiplied by 2, and the electron image of the electron-multiplied electron image is emitted by the phosphor screen 33 to convert the electron image, which retains the positional information, into an optical image again. However, the re-converted optical image of the subject 5 is transmitted from the fiber plate 30A to the eyepiece 4 to be imaged, and is observed by the photographer.

At this time, for example, the lighting of the infrared light emitting diode 6 and the infrared light emitting diode 6A is time-divided and Δt of FIG.
Since it overlaps for a time, the light emission of the fluorescent screen 33, in other words, the continuous emission of continuous flashing of the plurality of infrared light emitting diodes 6, 6A, 6B, despite the afterimage characteristics of the fluorescent screen 33, is taken. Person understands.

According to the above construction, since the plurality of infrared light emitting diodes 6, 6A, 6B are integrally embedded in the main body 1, operability and maneuverability can be improved, and the brightness is about the same as that of starlight. Even if the subject 5 becomes dark due to the loss of light, it is possible to prevent a decrease in the amount of light that enters the image intensifier 3 from the subject 5 and improve the performance of the high-sensitivity night-vision device.

In addition, a plurality of infrared light emitting diodes 6, 6A
・ 6B is not a single but is arranged in three triangles and buried,
Moreover, since it blinks sequentially at the timing shown in FIG. 10,
Any one of a plurality of infrared light emitting diodes 6, 6A, 6B
Will be lit, and the consumption of the dry battery 70 can be expected to be suppressed.

Further, since the infrared light sequentially radiated near the periphery of the image pickup center of the subject 5 partially overlaps at the image pickup center and cancels out the unevenness of the light amount mutually, regardless of the characteristics of the light emitting diode, It is possible to prevent unevenness in the amount of light from occurring in the center of imaging of the subject 5, and it is possible to clearly grasp the subject 5 even in the dark.

Further, for example, since the lighting of the infrared light emitting diode 6 and the infrared light emitting diode 6A overlap in a time-sharing manner for the afterimage time of the fluorescent screen 33, the fluorescent screen is displayed regardless of the afterimage characteristic of the fluorescent screen 33. In other words, it is possible to recognize the light emission of 33, that is, the blinking of the plurality of infrared light emitting diodes 6, 6A and 6B as continuous light.

In the above embodiment, three infrared light emitting diodes 6, 6A and 6B are arranged in a triangular shape and embedded, but the number of arrangements and the shape of the arrangement are not limited. is not. Further, although the MCP 32 is used in the above embodiment, it is needless to say that the present invention can be applied to the image intensifier 3 in which the MCP 32 is omitted. In this case, so-called image enhancement is achieved by increasing the acceleration voltage between the photocathode 31 and the fluorescent surface 33 to increase the energy of the electrons.

[0044]

As described above, according to the present invention, since a plurality of light sources are integrally embedded in the main body, operability and maneuverability can be remarkably improved, and at the same time the brightness of a starlight level can be obtained. Even if it is lost and the subject becomes dark, it is possible to reliably prevent a decrease in the amount of light that enters the image intensifier from the subject and significantly improve the performance of the high-sensitivity night-vision device. It has a great effect.

Further, according to the present invention, since the plurality of light sources are sequentially blinked, any one of the plurality of light sources is turned on, and it is expected that the consumption of the dry battery will be greatly suppressed and the running cost will be remarkably reduced. There is a remarkable effect that it can be done.

Further, according to the present invention, the infrared light of the light source sequentially irradiated in the vicinity of the periphery of the image pickup center of the object partially overlaps at the image pickup center and cancels the unevenness of the light amount with each other. Regardless of the characteristics of the light emitting diode,
There is a remarkable effect that it is possible to surely prevent the light amount unevenness from occurring in the imaging center of the subject, and to grasp the subject extremely clearly even in the dark.

Further, according to the present invention, since the lighting of one light source and the lighting of the other one light source overlap in a time-sharing manner for the afterimage time of the fluorescent screen, the fluorescent screen is displayed despite the afterimage characteristic of the fluorescent screen. In other words, there is a remarkable effect that the blinking of a plurality of light sources can be surely grasped as continuous continuous light.

[Brief description of drawings]

FIG. 1 is a right side view showing an embodiment of a night-vision device according to the present invention.

FIG. 2 is a plan view showing an embodiment of a night vision device according to the present invention.

FIG. 3 is a left side view showing an embodiment of the night vision device according to the present invention.

FIG. 4 is a front view showing an embodiment of the night vision device according to the present invention.

FIG. 5 is a rear view showing an embodiment of the night vision device according to the present invention.

FIG. 6 is an essential part explanatory view showing an embodiment of the night vision device according to the present invention.

FIG. 7 is an explanatory diagram showing a distribution of irradiation illuminance of a single infrared light emitting diode divided into X and Y axes.

FIG. 8 is an explanatory view showing a distribution of irradiation illuminance of a plurality of infrared light emitting diodes divided into X and Y axes.

FIG. 9 is an explanatory diagram showing a light source drive circuit of a night-vision device according to the present invention.

FIG. 10 is a timing chart showing blinking timings of a plurality of infrared light emitting diodes.

FIG. 11 is a timing chart showing a delay in lighting of the infrared light emitting diode and emission of light from the phosphor screen.

FIG. 12 is a timing chart showing a blinking timing of a plurality of infrared light emitting diodes and a light emitting timing of a phosphor screen.

FIG. 13 is a main part explanatory view showing a conventional night-vision device.

[Explanation of symbols]

1 ... Main body, 2 ... Objective lens, 3 ... Image intensifier, 4 ... Eyepiece lens, 5 ... Subject, 6.6A, 6B
Infrared light emitting diode (light source), 7 ... Light source drive circuit, 3
1 ... Photoelectric surface, 32 ... MCP (multiplier), 33 ... Fluorescent surface.

Front page continued (72) Inventor Hiroshige Takada 1 1126, Nomachi, Hamamatsu, Shizuoka Prefecture 1126 Hamamatsu Photonics Co., Ltd. (72) Inventor Doji Yonezawa 1126, Nomachi, Hamamatsu City Shizuoka 1 Hamamatsu Photonics Co., Ltd. (72) Inventor Shuyo Takeyama 1 1126, Nomachi, Hamamatsu, Shizuoka Prefecture, 1 Hamamatsu Photonics Co., Ltd. (72) Inventor Fumio Watase 1 1126, Nomachi, Hamamatsu, Shizuoka Prefecture Hamamatsu Photonics Co., Ltd. (56) References JP-A-2-44637 (JP, A) JP-A-58-129733 (JP, A) JP-A-61-296870 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 5/225 H01J 31/50

Claims (3)

(57) [Claims] 1. A plurality of light sources for irradiating a subject with infrared rays, a photocathode for converting an optical image of the subject formed by an objective lens into an electronic image, and a fluorescent screen for converting the electronic image into an optical image. An eyepiece lens for projecting an optical image displayed on the fluorescent screen to a photographer's eye, and a light source drive circuit for sequentially blinking the plurality of light sources to continuously emit light from the fluorescent screen due to incidence of electrons of an electronic image. The night-vision device, wherein the infrared rays emitted from the plurality of light sources have respective irradiation ranges partially overlapping with each other. 2. A plurality of light sources for irradiating an object with infrared rays, a photocathode for converting an optical image of the object formed by an objective lens into an electronic image, and a multiplication for multiplying the converted electronic image. Section, a fluorescent screen for converting the multiplied electronic image into an optical image, an eyepiece for projecting the optical image displayed on the fluorescent screen into the eye of the photographer, and a plurality of light sources sequentially blinking. And a light source drive circuit that continuously emits light from the phosphor screen associated with the incidence of electrons of an electron image, wherein the infrared rays emitted from the plurality of light sources have respective irradiation ranges partially overlapping with each other. Vision device. 3. The night-vision device according to claim 1, wherein the light source drive circuit overlaps irradiation timings of a plurality of light sources for an afterimage time of the phosphor screen having an afterimage characteristic.