DE29619074U1 - Miniature video camera with periscope optics that can be mounted on a dental lamp - Google Patents

Description

Description ·..··.·*

The invention is a miniature video camera with periscope optics that can be mounted on any dental light using a special tripod .

Intraoral cameras are increasingly being used in dentistry for documentation and patient demonstrations alongside normal video and photo cameras. With these intraoral cameras, the lens is inserted more or less far into the patient's mouth. The object - tooth or oral mucosa - is illuminated by cold light - light generated by distant halogen lamps, which is guided to the front lens of the lens using glass fibers. To take a picture, the intraoral video camera must be operated by either the dentist or his assistant. Treatment must therefore always be interrupted when using it, as either the clear view of the teeth etc. is obstructed or the lens (intraoral) has to be removed from the mouth for cleaning due to fogging or contamination (saliva, drilling chips etc.). Since the camera itself is operated with an electrical voltage (usually 12 volts), there is a residual risk of an electrical accident in the patient's mouth. These cameras have the following disadvantages:
1.) additional lighting

Additional lighting is necessary for their use (see above)
2.) Contamination

The camera optics are contaminated by contact with the patient’s mouth
and must therefore be disinfected, or better, sterilized, after each use.
3.) Fogging

Due to the temperature differences, cold camera optics/warm patient mouth
Most intraoral cameras fog up at the beginning of the recording.
4.) Electro-magnetic effects

Although all intraoral video cameras are operated with low voltage (12 volts),
However, a residual risk of an electrical accident cannot be completely ruled out.
5.) poor optical imaging

Since the optical entrance openings (lens systems) of these cameras are very
are small, imaging errors (aberrations, etc.) occur more frequently.
6.) poor ergonomics

When using intraoral cameras, the dentist must perform the treatment
interrupt and pick up the camera.

The extraoral cameras in the dental field are usually normal camcorders (camera-recorder combinations) that are attached to a separate tripod (floor or ceiling tripod) for recording or that have to be held by the dentist himself. The lighting is either the dental light or a separate light source outside the patient's mouth. These "normal" video cameras have the following disadvantages in the dental sector.

1.) Additional lighting

If you want to illuminate the patient's mouth optimally - without shadows - you need additional lighting that must come from the direction of the optical axis of the camera (camera light; for photo cameras, ring flash is best)

2.) Poor ergonomics and awkwardness The dentist or his assistant needs both hands to take the picture. In addition, the patient is denied a view of the monitor for the duration of the picture (because the dentist is standing in front of him).

3.) Intraoral images with a flanged mouth mirror are only possible to a limited extent.

The disadvantages of the above-mentioned construction types can be completely eliminated by the invention:

The invention uses the mobility and illuminance of a dental light to achieve optimal video recordings without interrupting the treatment process. The invention also uses the fact that shadow-free and optimal illumination of an object can only be achieved if the lighting is arranged in a circle around the optical axis of the recording lens and the light rays run parallel to the optical axis.

Optimal lighting through dental light

In the invention, the optical axis of the objective is moved to the center of the beam path of the dental light by the double beam deflection of the periscope optics and the extendable second mirror (Fig. 4). This avoids parallax errors (Fig. 7) and the image is always taken in the center of the light cone of the dental light. An intraoral image, eg of the back surface of a tooth, can be easily taken using a mouth mirror.

When the dentist illuminates the area to be filmed with his mouth mirror (light from the dental lamp reflected from the mouth mirror), the camera automatically records the illuminated area (Fig 6).

Exclusion of contamination and fogging of the optics

The light-mounted video camera with periscope optics makes any intraoral camera superfluous. This eliminates any contamination of the lens with saliva or blood and the resulting need for disinfection of the lens. The risk of infection for the patient due to dirty optics is completely eliminated.

No electromagnetic effects

Furthermore, the extraoral "intraoral camera" has the advantage that no electromagnetic voltages can occur in the patient's mouth (short circuits, etc.)

Good optical image

The relatively large lenses of the periscope optics (diameter approx. 20 mm) allow so much light to fall on the CCD chip that a strong stop-down can be achieved using the aperture (06) (Fig. 4). The small aperture results in a large depth of field and minimal optical imaging errors. (Imaging errors usually occur at the edges of the lens, which are blocked out here by the small aperture). The telephoto lens with a focal length of 120 or 150 mm (normal lens = 7 mm) displays the tooth and neighboring teeth in full format on the observation monitor at a normal working distance of 700 mm (light - patient's mouth). A magnification of 1:1 is possible when the light is brought closer to the patient's mouth.

Economic efficiency and ergonomics

The lamp tripod allows any dental lamp to be retrofitted with the invention. The quick-change tripod makes additional cameras - e.g. an additional camera in each treatment room - superfluous, as all that is required is to glue a (steel) cap onto each dental lamp and lay a cable for video/power supply and possibly audio.

During dental treatment, the center of the light cone (= the central beam) of the dental light must be aimed at the tooth to be treated.

Since the optical axis of the video camera is moved to the center of the beam cone, the assistant can check the exact setting of the light and the sharpness of the image on the monitor without the dentist having to worry about it. If the tooth to be treated is shaded by dental instruments or the doctor's fingers, a perfect image is impossible. This means that the dentist and assistant have constant control over the video recording and thus continuous observation and documentation of the dental treatment is possible without interrupting the treatment process. Another advantage is that the double beam deflection (periscope optics) means that all objects are shown laterally on the observation monitor.

Outlook (protection claim 8)

The same principle is used for surgical lights. The only difference is that these surgical lights are very large and heavy. In addition, surgical lights have a large number of lamps mounted around the camera in the center of the light. A miniaturized surgical light (Fig. 8+9) with a central video camera would also be useful for a dentist's office. However, the entire light and reflector would then have to be replaced, which would make the conversion of a practice considerably more expensive.

The invention converts a normal dental light into an operating light . With sufficient practice by the dentist/assistant team, eye-friendly treatment via video monitor may also be possible in the future (see operation with endoscope).

Drawings (Fig 1- 9) Parallax error:

In photography, parallax is the angle between the optical axis of the lens, the object being photographed and the viewfinder. The parallax error - what you see through the viewfinder does not match what is being photographed - thus becomes greater the closer you get to the object. Applied to the dental light, this means that the closer a camera mounted on the light comes to the patient's mouth, the further the central beam of the light and the optical axis of the video camera diverge (Fig. 7). In photography, this problem was solved with the SLR technology.

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Fig. 1 Light reflector with tripod cap and sleeve and Fig. 2 Light tripod

51 = glued cap

52 = Socket

53 = Knurled screws

54 = Tripod leg, lockable

55 = Ball head, lockable

56 = Sleeve

Fig. 3 Central beam/optical axis

A = optical axis D = optimal working distance: 700mm L = light cone

Fig. 4 Camera optics on light and Fig. 5 Focusing

K = Camera

C = CCD chip of the camera

L1 = Dental light

L2 = halogen lamp

L3 = luminaire reflector

SS = Beam path of the luminaire

SP1= Mirror 1

SP2= Mirror 2, adjustable in length

01 = Adapter piece

02 = External telescope

03 = Inner telescope

04 = Lens system

05 = Bracket for long adjustable front mirror

06 = aperture

07 = Focus lever Y = Focus travel

Fig. 6 optical axis in the mouth mirror Fig. 7 parallax error

Fig. 8 Dental light with integrated video camera (side view) and Fig. 9 Front view

K = video camera

T = telephoto lens

R = luminaire reflector

B = Ring-shaped lighting

L = light cone

H = Grab handles

T = Telephoto lens

Claims (1)

Protection claims ·..··.·* ' Miniature video camera with periscope optics that can be mounted on a dental light. The dental video camera is characterized by: Feature 1: A cap (S1) made of heat-resistant material with sleeve (S2) mounted (glued) on the back of the reflector of the dental light (Fig 1). Feature 2: A miniature tripod is inserted into the sleeve and can be quickly locked using a knurled screw (S3) (wing screw or similar) with a ball joint head (S6) that can also be locked in any position using a screw (S3) . This allows the optical axis of the camera to be aligned parallel to the central beam of any dental light (Fig . 2 and 3). Feature 3: A periscope optic with double 90-degree beam deflection - using optical mirrors (Sp1/Sp2) or prisms. This optic can be flanged to any video finger camera using an adapter piece (01). The periscope optic enables a parallel shift of the optical axis (A) of the video camera (Fig 4). Feature 4: A second mirror (Sp2) that is adjustable in length . This allows the optical axis of the video camera to be positioned exactly in the center of any dental light (Fig 4) to avoid parallax errors (Fig 7). Feature 5: A periscope optic with a long focal length of 120 or 150 mm (normal focal length with 1/2" CCD chip = 7 mm). The teeth to be treated are thus imaged on the observation monitor at an average distance (D) between the light and the patient's mouth of approx. 700 mm, with one neighboring tooth each (Fig. 3). · Even greater imaging dimensions for the finest tooth defects or gum diseases are achieved by bringing the dental light and thus the lens up to 300 mm closer to the patient's mouth. Bringing the dental light any closer would obstruct the dentist's view. Characteristic 6: One -handed quick focusing by telescoping the front lens pair (Fig. 5). The focusing path resulting from the given long focal length of 120 mm (with 1/2" CCD chip) and an object distance of 300-1000 mm is more than 40 mm. Fast focusing that can be done with just one hand is achieved by telescoping the front lens pair using two pins (07) that are moved against each other with the fingers. This focusing is initially only rough. Fine focusing is achieved by changing the object distance (distance between the light and the tooth) by swiveling the dental light back and forth (assistant). Focusing can also be done by turning the inner telescope in or out or by using a rack and pinion fine drive. Characteristic 7: Any tooth surface can be visualized using a standard mouth mirror that reflects the light from the dental lamp onto the tooth surface. This makes all intraoral cameras superfluous (Fig 6). Characteristic 8th: Protection is also claimed for a modification of the design, according to which the camera with a straight telephoto lens is attached to the centre of the lamp and the illumination of the mouth is achieved by means of a ring-shaped halogen lamp arranged around the camera and dimmed towards the front or by several lamps arranged in a circle in the reflector (Fig. 8 and Fig . 9).
A miniaturized surgical light for dental use.