WO2006000072A1

WO2006000072A1 - System and process to capture, store and show stereoscopic images

Info

Publication number: WO2006000072A1
Application number: PCT/BR2005/000123
Authority: WO
Inventors: Jorge Mitre
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-06-29
Filing date: 2005-06-29
Publication date: 2006-01-05
Anticipated expiration: 2006-12-29
Also published as: BRPI0402602A

Abstract

System and process to capture, store and show stereoscopic images constituted by a stereoscopic binocular ophthalmologic instrument (12) having two cameras (18a, 18b) to capture image components corresponding to the right and left eyes, a multiplexator (21) to generate a multiplexed video signal, transmission means of the multiplexed video signal, at least one video image reproducing device (25), at least one viewing device (27) provided with blocking and unblocking means (27d, 27e) of the view of each eye and synchronizing means of the referred unblocking. Said instrument may be a stereoscopic binocular microscope or a biomicroscopy instrument lighted by a slit lamp.

Description

SYSTEM AND PROCESS TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES

Field of the invention

The present invention refers to the field of capturing, reproducing and showing images in three dimensions, commonly known as 3-D, particularly suitable for applying in medicine, in surgery and, especially, in ophthalmology.

Description of the state of the art

To perceive depth, i.e., the capacity of the brain to see the environment in three dimensions, is based on the fact that the right and left eyes see such an environment from different viewing angles. Thus, the images captured by both eyes are slightly different, such a difference making spatial or in 3-D perception possible.

There are processes already known in which images registered from different points of view are supplied to the observer. Such technique, generally called stereoscopy, is based on the fact that said different images are supplied to the observer's right and left eyes. A well-known example is that of the Viewmaster equipment in which the photographic images are captured by cameras equipped with two separate objective lenses, separated by a distance substantially equal to that of human eyes. The view of these images, under the form of transparencies, is carried out through separated oculars by the right and left eyes.

The stereoscopic techniques are not limited to static images; they can also be used for moving images. The first applications in this field were the currently obsolete cinemas 3- D, in which the images corresponding to scenes seen by the right (R) and left (L) eyes were recorded on the same film frames using different colours, for example, red and blue. For spectators to see they had to use eyeglasses with different colour lenses for each eye, said colours acting as filters that allowed each eye to view only the image capture from the R or L point of view. Obviously, the use of different colours resulted in a precarious image quality, consequently, such system was abandoned. A more perfected system is based on separating the R and L images using different polarizations, generally orthogonal in relation on to the other. An example of this technique is described in document WO0055687, in which images with different polarizations are recorded and/or transmitted separately and projected simultaneously on a screen by different projectors, keeping the original polarizations. The spectators must use eyeglasses with differently polarized lenses for the R and L eyes, so each eye only captures the image corresponding to it.

As well as to requiring the use of two projectors, the above mentioned system has a disadvantage of the quality of the image being influenced by the observer' s head movement. Indeed, the inclination of the eyeglasses impairs the filtering capability of the polarized images, resulting in a deterioration of the stereoscopic effect. In addition, both in the systems based on differential polarization and in those that use different colours for the R and L eyes, the colour reproduction quality is precarious, being substantially worse than that of conventional coloured television sets.

Objectives of the invention

Because of the above, a first objective of the invention constitutes providing a 3-D system where the observer' s head movement does not impair the stereoscopic reproduction quality.

Another important objective constitutes providing a system and method particularly suitable for ophthalmology.

Another objective constitutes providing a system and method that are easily adaptable to surgical microscopes as well as to de biomicroscopy instruments (slit lamp or the like) .

Another objective constitutes providing a system that allows the documentation of surgical interventions and ophtalmoscopic images

Another objective constitutes providing a system where the colour reproduction is comparable with that obtained in coloured TV sets or video monitors. Brief description of the invention

The invention attains the above objectives by- providing a system where two cameras coupled to a stereoscopic ophthalmologic instrument are used, the images captured by said cameras being multiplexed in time and transmitted or recorded on a sole video channel, being reproduced in the form of a sequence of alternated R and L images by means of a monitor or projectors.

According to another characteristic of the invention, the capturing of images is carried out by deviating part of each of the beams by means of a beam slitter placed between each ocular and objective lens of the instrument.

According to another characteristic of the invention, the capturing of images is carried out by two cameras directly coupled to the observer's oculars.

According to yet another characteristic of the invention, said instrument consists of a stereoscopic ophthalmologic microscope.

According to yet another characteristic of the invention, said instrument consists of a biomicroscopy instrument by slit lamp.

According to another characteristic of the invention, the viewing occurs by means of visualizers equipped with a selective occlusion optical system, capable of blocking and unblocking the view of each eye, alternatively.

According to another characteristic of the invention, said alternation is synchronized with the image alternation showing on the screen.

According to another characteristic of the invention, said visualizes consist of eyeglasses equipped with lenses with liquid crystal elements.

Description of the drawings

The characteristics and advantages of the present invention will be understood through the description of the preferred embodiments given as examples and the drawings that refer to them, where:

Fig. 1 shows, by means of a block diagram, the general display of the proposed system.

Fig. 2 shows, by means of a block diagram, a second embodiment of the invention.

Detailed description of the invention

According to the principles of the invention and in conformance with what is shown semi-schematically in Fig. 1, which shows an application in ophthalmologic surgery, the system proposed comprises a stereoscopic microscope 12 focused on the operating field, in the case the patient's right eye 10, the image being captured by two optical systems corresponding to the surgeon's right and left eyes. As shown in the drawing, between each objective lens 11a, lib and the respective ocular 22a, 22b a beam slitter, formed by a semi-mirrored transparent sheet 15a, 15b ("beam slitters") that divides each beam 13a, 13b into two components, is placed. The first goes through the referred element and follows in a straight line up to the corresponding ocular 22a, 22b and the second 17a, 17b is reflected in a 90 degree angle being directed towards one of the cameras 18a, 18b, which capture the R and L images transforming them into video electrical signals.

The electrical signals supplied by the cameras are sent via lines 20a, 20b to multiplexator 21, where a commutation circuit forms a sole signal by means of the switching between the R and L channels, multiplexing them in time, corresponding to an alternated image sequence captured by each camera.

The multiplexed signal may be recorded on digital media, such as a DVC on a recorder 23, or transmitted for reproduction in real time, through a communication means, to one or more video monitors 25, which can be a common television set. Another way of showing is by means of two projectors pointed towards a screen and also by a computer.

To observer the image, the observer must use an especial visualizer, represented in the drawing by a pair of eyeglasses 27, provided by an occlusion optical system, to unblock the light transmission, first by one, then by the other lens. This unblocking occurs alternatively with the same frequency of the R and L images showing on the monitor's screen. The synchronism between the image on the screen and the mentioned unblocking is provided by line 28, which sends to eyeglasses 27 the image commutation synchronism component extracted from the video signal by the separating circuit 24. Thus, the unblocking of the right lens 27d is assured when the R image is being shown on the screen, the left lens 27e being unblocked when the L image is shown.

The commutation frequency of R and L images if sufficiently high to avoid any scintillation. In addition, occlusion and unblocking of lenses may be provided by devices based on liquid crystal, which have the advantage of reduced costs.

Obviously the image may be visualized by a plurality of observers, being enough for such that they are all provided with eyeglasses 27 synchronized by lines 28. A alternative way of providing this synchronization without using wires, consists in using infrared or radio links, which will require that the eyeglasses are equipped with proper receivers and batteries. In the case of auditoriums with seats equipped with sound distribution system, the same system can be used to provide synchronism, by sending ultrasound signals in the same audio line. The plug that normally would be used to couple the earphones to the connector provided in every seat will be modification, in this case, in order to provide ultrasound filtering, its treatment and sending to the eyeglasses by a separate line or by the eyeglasses themselves.

Fig. 2 shows a second embodiment of the invention, where cameras 18a and 18b are coupled direct to the respective oculars, the other parts of the equipment remaining unaltered.

Although the invention has been described based on a preferred embodiment, modifications can be introduced by those skilled in the art, keeping within the basic inventive concept. Thus, for example, instead of using video monitors or conventional television sets, it will be possible to, in the case of large audiences, show the images by means of one or two projectors. Additionally, the video signal transmission means between multiplexator 22 and the showing site are not limited to physical lines (metallic or optic fibres) being possible to use links via radio, microwaves, TV channel or satellite. Likewise, the recorded material on DVC can be transported and reproduced in the most different locations or occasions, and also by two projectors with R and L polarized filters and observer (s) with polarized eyeglasses (dismissing in this case the alternated occlusion) .

Accordingly, the invention is defined and e outlined by the following claims as a whole.

Claims

1. SYSTEM TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES characterized by the fact of comprising a stereoscopic binocular ophthalmologic instrument (12) provided with two cameras (18a, 18b) to capture the components of images corresponding to the right and left eyes, a multiplexator (21) to generate a multiplexed video signal, transmission means of the multiplexed video signal, at least one video image reproducing device (25) , at least one viewing device (27) provided with blocking and unblocking means (27d, 27e) of the view of each eye and synchronizing means of the referred unblocking.

2. SYSTEM TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES according to claim 1 characterized by the fact of the said stereoscopic binocular ophthalmologic instrument (12) being a stereoscopic binocular microscope.

3. SYSTEM TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES according to a claim 1 characterized by the fact of the said stereoscopic binocular ophthalmologic instrument (12) being a biomicroscopy instrument provided with light by a slit lamp.

4. SYSTEM TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES according to claims 1, 2 or 3 characterized by the fact of being provided with a beam slitter (15a, 15b) placed in the path of each beam (13a, 13b) said beam slitters providing the division of said beams in first components (16a, 16b) and in second components (17a, 17b) substantially orthogonal to the first and two cameras (18a, 18b) to capture said second image components.

5. SYSTEM TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES according to claims 1, 2 or 3 characterized by the fact of said cameras (18a, 18b) being coupled direct to the oculars (22a, 22b) of said instrument (12) .

6. SYSTEM TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES according to claim 1 characterized by the fact of comprising a recording device (23) of the multiplexed video signal.

7. SYSTEM TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES according to claim 1 characterized by the fact of said video image reproducing device (25) being provided with one or two video projectors and a projection screen.

8. SYSTEM TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES according to claim 1 characterized by the fact of said viewing device (27) being provided with a pair of eyeglasses with devices based on liquid crystal (27d, 27e) .

9. METHOD TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES characterized by the fact of comprising the following steps:

• capturing the right (R) and left (L) images by means of two cameras (18a, 18b) associated, each one, to one of the beams (13a, 13b) coming from the operating field and captured separately from different points of view by the objective lenses (Ha, lib) of a stereoscopic binocular ophthalmologic instrument (12) ;

• converting the said images into the corresponding electrical signals by said cameras;

• forming a sole signal by multiplexing in time said signals supplied by said cameras, corresponding to a sequence of alternated images captured by each camera;

• transmitting said multiplexed signal to the showing device (25) ;

• showing the sequence of images by the alternated projection of the images captured separately, in the showing device (25) .

• Viewing the image through view blocking and unblocking means of the right and left eyes (27, 27d, 27e) , synchronized with said showing.

10. METHOD TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES according to claim 9 characterized by the fact of comprising the division of each beam (13a, 13b) into a first component (16a, 16b) and a second (17a, 17b) component substantially orthogonal to the first, the latter being captured by the respective video camera (18a, 18b) , said first component being transmitted to the ocular (22a, 22b) of the instrument.

11. METHOD TO CAPTURE, STORE AND SHOW STEREOSCOPIC IMAGES according to claim 9 characterized by the fact of comprising the recording of said multiplexed signal on digital storing means (23) .