JPH0530402Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field The present invention projects a light beam from a light source onto a mirror installed in a CCD camera through a light guide, and illuminates the inside of the oral cavity with the reflected light. The present invention relates to a dental imaging device that captures an image of the inside of the oral cavity with a CCD camera via a mirror and displays the image on a CRT or the like.

Prior Art Conventionally, as a light source for illuminating the inside of the oral cavity in the above-mentioned imaging device, a light source that cuts out infrared rays as much as possible has been used. The light source used for this purpose is usually a halogen lamp. Halogen lamps contain a large amount of infrared rays, so if the halogen lamp is directly irradiated into the oral cavity, the patient will feel heat at the irradiated area. The inside of the oral cavity is irradiated through an optical fiber and a mirror.

Purpose In the above-mentioned conventional technology, the irradiated area is not heated and is suitable for patient treatment. On the other hand, when the mirror is inserted into the oral cavity, the patient's exhaled air hits the mirror and the temperature of the mirror is lower than the exhaled air (the mirror has the same temperature as room temperature, so the temperature is usually lower than the exhaled air). Moisture in exhaled air condenses on the mirror surface, causing cloudiness. Therefore, before inserting the mirror into the oral cavity, either warm it up by holding it over a burner flame before starting treatment, or wait a little while until the cloudiness clears before taking an image. However, once the mirror is removed from the oral cavity, it quickly returns to room temperature, causing the same problem each time it is inserted into the oral cavity, adding to the hassle and prolonging the treatment time.

The present invention uses the light beam from the light source to heat the mirror itself, thereby eliminating fogging of the mirror.

Configuration The present invention is premised on the use of a light source device that does not, in principle, need to cut out infrared rays. Of course, the light source device may be a light source device that cuts out an appropriate amount of infrared rays by using an appropriate filter or the like in order to adjust the heating conditions for use as described later.

As a mirror, it transmits light in the infrared region,
A dichroic mirror that reflects visible light is used. It is obvious from the nature of the invention that physical rigor is not required for these cutoff frequencies and cutoff characteristics. A light absorber is provided behind the mirror, preferably in close contact with it.
The light absorber may be made of a suitable material such as a ferrite plate, a metal plate treated with black, paper, or cloth. The point is, all you have to do is absorb the infrared rays that pass through the dichroic mirror, generate heat, and raise the temperature of the dichroic mirror appropriately.
It may also be a membrane provided on the back surface of the mirror.

FIG. 1 is an overall configuration diagram for explaining one embodiment of the present invention. In the figure, 1 is a mirror, the details of which will be described later. Reference numeral 5 denotes a light source device, which transmits illumination light flux to the light projection device 2 via the connection portion 4 and the optical fiber 3, and projects it from the light projection device 2 toward the mirror 1. 9 is a device for adjusting and holding the mirror;
The mirror is held, for example, at an angle of approximately 45 degrees with respect to the projected light beam. 6 is a CCD camera, 10 is
The camera holder 10 is a camera holder to which a CCD camera 6 is detachably attached.A light projection device 2, a mirror holding device 9, etc. are attached to the camera holder 10.
The output of the camera 6 is transmitted via a cable 7 and projected onto the screen of a video device such as a CRT via a connector 8.

FIG. 2 is a diagram showing details of a conventional light source device.
In the figure, 50 is a halogen lamp, 51 is a cold-treated reflector, 52 is heat-insulating glass, and 53 is a cooling fan. The treated reflection plate 51 absorbs the visible light, and only visible light is introduced into the optical fiber 3 via the connection part 4. However, since the present invention attempts to prevent the mirror 1 from fogging by warming the mirror 1 using heat ray components from the light source, the light source device according to the present invention uses heat rays such as infrared rays as the reflecting plate 51. A normal reflecting plate that reflects both the visible light source and the visible light source is used, and no heat-insulating glass 52 or the like is used. Therefore, in the present invention, the light including both infrared rays and visible light emitted from the halogen lamp 50 is transmitted to the connecting portion 4.
is introduced into the optical fiber 3 via.

FIG. 3 is an enlarged view of an example of the mirror 1. This mirror 1 absorbs heat rays such as infrared rays,
A dichroic mirror 11 that reflects visible light, a light absorber 12 that absorbs heat rays such as infrared rays, and a cover 1
Consists of 3. The cover 13 is preferably made of a material with low heat capacity, such as synthetic resin. dichroic mirror 11
is designed to transmit light in the infrared range and reflect light in the visible range. Of course, a concave mirror may also be used. The light absorber 12 is made of a black paint mixed with metal powder to increase its heat capacity, and is applied to the back surface of the dichroic mirror 11.

Let's talk about the action. The light beam projected onto mirror 1 enters the mirror at an angle of approximately 45 degrees. mirror 1
Since 1 is the above-mentioned dichroic mirror, the infrared component passes through the dichroic mirror 11 and enters the light absorber 12 to heat it.
As the temperature of the light absorber 12 increases, the dichroic mirror 11 is heated. The heating temperature is preferably close to body temperature, but can be set to an appropriate temperature by considering the cooling coefficient of each part, light source, filter, etc. This temperature increase causes
Even when the mirror 1 is inserted into the oral cavity, moisture in the patient's breath can be prevented from condensing on the mirror surface. In addition, the inside of the oral cavity is reflected by a dichroic mirror and imaged by a CCD camera.

Effects As mentioned above, by using a dichroic mirror and installing a light absorber behind it,
The mirror can be heated by the light beam from the light source, and fogging can be prevented. Since heating is performed at all times while the light source is on, there is no need to perform heating each time the device is inserted into the oral cavity, which can shorten treatment time. Further, there is no need to take special measures to cut out infrared rays as a light source, and the cost can be reduced accordingly.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram for explaining an embodiment of the present invention, FIG. 2 is a diagram for explaining details of a light source device, and FIG. 3 is a diagram for explaining details of a mirror. DESCRIPTION OF SYMBOLS 1... Mirror, 2... Light projection device, 3... Light guide cable, 5... Light source device, 51... Halogen lamp, 11... Dichroic mirror, 12...
...Light absorber, 13...Cover.

Claims (1)

[Scope of utility model registration request] It has a CCD camera, a holder that holds the CCD camera, a mirror and a light projection device that are adjustably attached to the holder, and a light source device that supplies visible light and infrared rays to the light projection device through an optical fiber or the like. and illuminating the oral cavity by projecting visible light and infrared rays from the light projection device onto the mirror;
In a dental imaging device in which the image reflected on the mirror is captured by the CCD camera, the mirror includes a dichroic mirror that transmits light in the infrared region and reflects light in the visible region, and a back surface of the dichroic mirror. A dental imaging device comprising: a light absorber disposed in the infrared region for absorbing light in the infrared region and warming the dichroic mirror.