JPH0516009B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope imaging device that is capable of photographing with a wide range of sharp images.

In recent years, endoscopes have become widely used in the medical and industrial fields. In particular, in the medical field, it is not only necessary to bring the eye close to the eyepiece of an endoscope to directly observe the target area within the body cavity.
Attach a camera, TV camera, etc. to the eyepiece,
(Photography) It is widely practiced to take pictures and record the appearance of the target area. In such cases, when observing with the naked eye, the operator can adjust his or her own diopter to correct even if the image is formed at a position that deviates from the predetermined image formation position, thereby obtaining a clear observation optical image. be able to.

However, when using a camera or television camera, the photographing lens system must be set at a position that forms a clear optical image on a predetermined photographic plane or image forming plane, that is, the focal position (point). In mirror photography, there has recently been a strong desire to increase the magnification (focal length f) of the photographic optical system to obtain an enlarged image, and since photography is often done at a short distance, the depth of focus is shallow.

Therefore, as disclosed in Japanese Patent Application Laid-open Nos. 56-128132 and 1982-128134 by the present applicant, the adapter lens of the imaging device attached to the rear of the endoscope eyepiece can be moved back and forth. There is a conventional example in which an operator can confirm that a sharp image is formed on a predetermined imaging plane using a focusing means and then take an image.

However, in these conventional examples, the aperture moves in conjunction with the focus means, so although they have the advantage of not requiring an operation to adjust the aperture, depending on the shooting distance, the depth of focus may be made shallower than necessary. There were times when I had to put it away. Therefore, the depth of focus is shallow even when checked with the eyes of a surgeon who has the ability to correct, resulting in a so-called "out of focus".
The photographed image was sometimes taken.

For this reason, there has long been a desire for an imaging device that can take clearer images without sacrificing operational functionality.

The present invention has been made in view of the above-mentioned problems.In order to deepen the depth of focus during photography, it is possible to take photographs by turning on a photography lamp with a large amount of light, such as a strobe flash, with the aperture sufficiently closed. It is an object of the present invention to provide an endoscopic photographing device that makes it possible to obtain photographed images with a deep depth of focus.

Hereinafter, the present invention will be specifically described with reference to the drawings.

1 to 6 relate to one embodiment of the present invention, in which FIG. 1 shows the overall configuration of one embodiment, and FIG.
5 to 5 show an embodiment of the aperture mechanism used in one embodiment, and FIG. 6 shows a control system in one embodiment.

In these figures, a rigid endoscope 1 includes a rigid and elongated insertion section 2, a thick operation section 3 connected to the rear end of the insertion section 2, and a rear end of the operation section 3 placed on the rear side. It is comprised of an eyepiece section 5 which expands into a tapered shape and houses an eyepiece lens 4 therein.

A light guide base 6 is protruded from the side of the operation unit 3, and a light guide (cable) 7 is detachably attached to the light guide base 6 to emit collimation light from a light source device 8 or during photographing. An illumination optical system is formed in which photographing light is supplied and is emitted from the distal end of the insertion section 2 toward a subject such as an organ 9 in front by a light guide (not shown) inserted through the insertion section 2.

The subject illuminated by the emitted light is imaged by an objective lens (system) disposed within the distal end of the insertion section 2, and is transmitted to the rear eyepiece via an image transmission means such as a relay lens system. By transmitting the light to the lens 4 side and bringing the eye close to the exit pupil at the rear end of the eyepiece 5, an observation optical system that can be observed with the naked eye is formed and can be attached to and detached from the eyepiece 5. By attaching the photographing device 11, the camera is configured to be capable of photographing.

In the illustrated example, the photographing device 11 includes an adapter section 12 attached to the eyepiece section 5, and a main body section 1 (photographing device) attached to the rear end side of the adapter section 12.
It consists of 3.

A recess is formed at the center of the front end of the adapter section 12, and the side periphery of the recess is tapered so as to come into contact with the outer periphery of the endoscope eyepiece section 5, so that the endoscope 1 and the adapter section 1 can be connected to each other.
A locking piece is attached to attach and detach 2.

In the adapter section 12 which is behind the eyepiece section 5 on the optical axis 14 of the observation optical system of the endoscope 1 when attached to the endoscope 1, the opening amount is adjusted by a light amount control means. A diaphragm 15, a photographing lens 16, and a beam splitter 17 are arranged in this order.

The aperture 15 is rotated by a driving means 18 such as a motor, and the driving means 18 is rotated.
As shown in FIGS. 2 to 5, a light amount control means is formed that can adjust the amount of transmitted light by changing the area of the opening.

The photographing lens 16 is configured to be movable back and forth on the optical axis 14 to change the imaging position. The beam splitter 17 behind this lens 16 is formed by joining two triangular prisms, etc., and allows most of the light to proceed toward the main body 13 at the rear on the optical axis 14, while also transmitting a part of the light The light is reflected and branched, passes through a photometric lens 19, and is received by a photometric photoelectric element 21 behind a mask 20 provided with an aperture.
The photometric circuit 22 is configured to amplify the amount of light incident on the aperture 15 and measure it.

The signal measured by the photometry circuit 22 is transmitted to the light source device 8 side via the camera cord 23, and the light emission amount control circuit 24 in this light source device 8 controls the amount of light emitted at the time of photography to reach the appropriate exposure amount. It is configured so that it can be controlled such as stopping light emission when

On the other hand, a mirror 25 is arranged on the optical axis 14 behind the beam splitter 17 in the main body 13 attached to the adapter part 12, and is inclined with respect to the optical axis 14, and a predetermined coupling is provided behind the mirror 25. A photographic film 26 is disposed at the image position, and this film 2
A part of the reflected light from the optical image formed on the six surfaces is directly transmitted through the photometric lens 27 and then by the photoelectric element 28.
It is constructed so that the amount of light of the optical image formed on the film 26 surface can be directly measured.

Behind the optical axis reflected by the mirror 25 (upward in the figure) is a pentaprism 29 for restoring horizontal reversal to a normal state, and behind the optical axis reflected by the pentaprism 29 is a finder lens 30. It is configured such that an optical image equivalent to that formed on the surface of the film 26 can be observed from behind the finder lens 30.

In normal observation conditions, the mirror 25 reflects all the light and blocks the light that goes to the film 26 side, and when photographing, it rotates and retreats from the position shown in the figure (Fig. 1) to form a beam splitter. The structure is such that the light passing through the ivy 17 is imaged on the surface of the film 26.

In the light source device 8, a collation lamp 31 for collation and a photographing lamp 32 are housed. It is configured so that the illumination provided by the photographic lamp 31 and the powerful photographic light condensed by the condensing lens 34 from the photographic lamp 32 can be switched and used.

By the way, the aperture 15 is configured as follows, for example.

That is, the diaphragm 15 has two diaphragm plates 38 and 39 provided with triangular openings 36 and 37 centered on the optical axis 14, respectively, in opposite directions (in the figure, the diaphragm plates 38 and 39 are pointed at arrows A and 39, respectively). Opening 3 by sliding it vertically (as shown in B)
The opposing triangular vertices 6 and 37 move in opposite directions with the optical axis 14 as the opening center, and the diamond-shaped openings 36 and 37 at the overlapping portions function as a diaphragm for adjusting the amount of transmitted light. has been done.

A slightly laterally elongated hole 40 is formed in the upper side of one of the aperture plates 38, and a crank arm 41, which is attached to the rotating shaft of the driving means 18, is provided in the hole 40 so as to protrude from the end of the crank arm 41. The aperture plates 38 and 39 can be moved up and down by guide pins 45 that accommodate the pins 42 and are accommodated in vertically long holes 43 and 44 formed in the aperture plates 38 and 39 at positions below the holes 40. It is regulated to move in each direction.

Furthermore, vertically long holes 46 and 47 are formed at the center of the lower part of the aperture plates 38 and 39, and a guide pin 49 is inserted into the holes 46 and 47 through the center hole of the arm 48.
It is housed in 7. Pins 50 and 51 are provided protruding from both ends of the arm 48, and these pins 50 and 51 connect to the holes 4 of the aperture plates 38 and 39.
They are housed in horizontal grooves 52 and 53 provided on the left and right sides of 6 and 47, respectively. A guide pin 49 is housed through a hole in the center of the arm 48 so as to be the center of rotation, and a spring 54 is wound around the guide pin 49, and one end of the spring 54 is locked with one pin 50. The other end is the adapter part 12
The aperture plates 38 and 39 are fixed to the side wall and biased in the direction in which the openings 36 and 37 are most open, that is, in the direction opposite to the arrows A and B. From this state, the signals of the drive circuit, which will be described later, are Drive means 18
is rotated in the direction of the arrow C, and the pin 42 attached to the end of the crank arm 41 and housed in the hole 40 is rotated and moved in the direction of the arrow D, and the pin 42 is rotated in the direction of the arrow D. , 44 and these holes 43, 44
The aperture plate 38 is
moves upward, and when the left pin 50 rotates upward as shown by arrow E around the guide pin 49 passed through the holes 46, 47 on the lower side and the center hole of the arm 48, the other pin 51 rotates downward to move the other aperture plate 39 downward, and the opening 3
The overlapping diamond-shaped opening portions 6 and 37 are configured to be variable in the direction of decreasing size. When the drive means 18 rotates in the opposite direction, the aperture plate 3
8 and 39 move in the opposite direction to the above and open the opening 3.
The overlapping diamond-shaped aperture portions 6 and 37 are configured to be variable so as to become larger.

The electric circuit system for controlling the light quantity control means and the like is constructed as shown in FIG.

That is, when the main switch 55 is turned on, each device is turned on and operates, and a signal from the control circuit 59 is transmitted to the light source device 8 via a line 57 in the camera cord 23 provided with a connector 56. . A portion of the light equivalent to that which is imaged on the film surface 26 by the photographic lens 16 in the illumination state by the collimation light is split by the beam splitter 17, and passes through the lens 19 to the photometric photoelectric element. 21 receives the light, photoelectrically converts the amount of the received light, and transmits it to the detection circuit 58. This detection circuit 58 amplifies and detects the amount of light, and the detection signal is transmitted to the control circuit 59, which drives the drive means 18 via the drive circuit 66, so that the aperture is sufficiently apertured even during observation using collimation light. 15, so that the light intensity of the collation light is at maximum or close to maximum,
Light emission amount control circuit (control of collation light and photographing light) 24
It is configured to be controlled by

When photographing, by turning on the release switch 61 attached to the main body 13, one input terminal of the two-input AND circuit 63 changes from low level to high level (to open the gate) via the connector 62. A photometric signal from the control circuit 59 is transmitted to the light emission amount control circuit 24 in the light source device 8 via an AND circuit 63 and a line 65 in the camera cord 23 connected by a connector 64.
The photographing lamp 32 with a large amount of light is turned on. on the other hand,
At the same time, a signal is sent from the control circuit 59 to the drive circuit 66, and the aperture amount of the diaphragm 15, which is in a state where the intensity of the collation light is sufficiently narrowed down at the maximum or close to the maximum, changes even when the photographing lamp is lit. controlled so that it does not occur. Under the illumination of this photography lamp 32, a portion of the amount of reflected light of the optical image formed on the surface of the film 26 in a sufficiently apertured state is transferred to the photometering photoelectric element 2.
8 (see Figure 1) or beam splitter 17
The light divided by is received by the photoelectric element 21,
When the exposure amount suitable for photographing is reached, a signal (low level from the control circuit 59) is sent to the light emission amount control circuit 24 to stop the photographing lamp 32 from emitting light.

The operation of one embodiment of the present invention configured in this manner will be described below.

An embodiment of the present invention is attached to a rigid endoscope 1,
Set the distance suitable for observing or photographing the target object such as the internal organs 9, and then turn the viewfinder lens 30
While observing from the rear, the photographing lens 16 is moved back and forth to set it at a position where it can be observed sufficiently clearly.

By turning on the main switch 55,
Detecting the light amount of an optical image that is equivalent to that formed on the film 26 surface under illumination with collimation light at maximum illumination intensity or near maximum illumination intensity,
The detected signal causes the diaphragm 15 to be sufficiently closed down, so that an optical image with a deep depth of focus is formed.

When the release switch 61 is turned on in order to photograph the subject observed in this state, the mirror 25 is retracted, the photographing lamp 32 with a large amount of light is turned on, and the aperture 15 is sufficiently closed down. The image is formed on the film 26 with a deep depth of focus. The reflected light from the optical image formed on the surface of the film 26 is transmitted to the photoelectric element 28, or a part of the light split by the beam splitter 17 is transmitted to the photoelectric element 21.
When the appropriate exposure amount for photography is reached, the light emission control circuit 24 stops the photography lamp 32 from emitting light, and returns the mirror 25 to its original position, that is, when the film is exposed. 2
Return to the position where the light does not reach the 6th side.

Photographs obtained in this manner have less so-called "out of focus" because they are photographed with a sufficiently apertured depth of focus. Furthermore, since the amount of light emitted from the photographing lamp 32 is controlled during photographing, photographing can be performed without requiring any skill or operation to select the aperture 15.

It should be noted that the present invention can be applied not only to a camera but also to a television camera as the photographing device 11. Although not shown, the present invention can be applied to a film 26 used for photographing, an image sensor (MOS image sensor,
Charge transfer devices such as CCDs or charge coupled devices,
Sensitivity of charge injection type devices such as CID (e.g. ASA
etc.), the amount of light emitted can be selected and controlled by manual operation of a setting switch provided on the light source device 8 or a switch attached to the adapter section 12 or the main body section 13.
When the proper exposure amount is reached, it is detected and the light emission is stopped.

In addition, when the photography lamp 32 is operated for only a short period of time (it may be possible to use it for a relatively long period of time by using forced cooling), it uses a much larger amount of illumination light than when it is used as a collimation light. Since it is possible to inject
Depending on the capacity of the photographing lamp 32, photographing can be performed with the diaphragm 15 further closed down from the sufficiently closed state during collation observation. In this case, by detecting the (total) amount of light irradiated onto the end surface of the light guide 7 by the collimation lamp 31 and the photography lamp 32, it is possible to accurately set the amount of further narrowing down (automatically or manually). become.

Further, in the above-described embodiment, the light amount control means for controlling the aperture amount of the diaphragm 15 is housed on the adapter part 12 side, but of course the light quantity control means is not limited to this, and it may be housed on the main body part 13 side. It's okay.

Note that it is clear that the adapter section 12 and the main body section 13 are not limited to being separable, but may be integrated.

Although examples of the light amount control means are shown in FIGS. 2 to 5, the invention is not limited to these examples, and many mechanical diaphragms that have already been disclosed may be used.
Alternatively, any means that makes it possible to vary the amount of transmitted light using a liquid crystal or the like may be used in the same manner.

Furthermore, by moving the photographic lens 16 to an appropriate position, it is possible to widen the range in which clear photographs can be taken; however, in the present invention, the depth of focus is increased, so it is possible to photograph at close distances where the depth of focus is shallow. In the state of illumination light (due to reflection from the subject)
becomes larger, so by using the light amount adjustment means,
The aperture is narrowed down further and the depth of focus becomes deeper, creating a pseudo-autofocus effect.
Therefore, there are cases in which photography can be carried out without any practical problem even if the photographing lens 16 is not moved.

Note that the photoelectric element 28 that directly receives the reflected light from the surface of the film 26 is not necessarily required, and the photoelectric element 21 that receives the amount of light split by the beam splitter 21 can reduce the amount of illumination light. It is also possible to perform photometry for both the shooting light and the shooting light.

Furthermore, it is clear that the present invention can be applied not only to rigid endoscopes but also to flexible endoscopes.

As described above, according to the present invention, since the aperture is sufficiently narrowed down by the photometry means to take a picture, it is possible to take a clear picture with little out of focus. . Furthermore, since the amount of light emission is automatically stopped when the appropriate amount of exposure is reached, clear photographed images can be obtained without requiring any skill.

[Brief explanation of the drawing]

1 to 6 relate to an embodiment of the endoscopic imaging device of the present invention, FIG. 1 is an explanatory diagram showing the entire optical system of the embodiment, and FIG. 2 is an explanatory diagram showing the entire optical system of the embodiment. Figure 3 is a side sectional view of Figure 2, Figure 4 is a bottom sectional view of Figure 2, and Figure 5 is a front view showing the structure of the aperture.
This figure is an exploded perspective view showing the vicinity of the lower part of FIG. 2, and FIG. 6 is a circuit diagram showing the configuration of the electric circuit system of one embodiment in a block diagram. DESCRIPTION OF SYMBOLS 1... Endoscope, 5... Eyepiece part, 8... Light source device, 11... Photographing device, 12... Adapter part, 1
3...Main body, 15...Aperture, 16...Photographing lens, 17...Beam splitter, 18...Driving means, 21, 28...Photoelectric element, 22...Driving circuit, 24...Light emission amount Control circuit, 25...mirror,
26...Film, 31...Lamp for collation, 32
...Photography lamp, 36, 37...Opening, 3
8, 39...Aperture plate, 57...Light amount detection circuit, 5
9...Control circuit.

Claims (1)

[Scope of Claims] 1. An optical image of a subject is formed by an objective optical system on the distal end side of the insertion section, and is attached to an eyepiece of an endoscope that can be observed from the rear of the eyepiece through an image transmission means. An imaging device that forms an optical image of a subject on a predetermined imaging plane, comprising: a photometer that measures a part of the amount of light that is imaged on the predetermined imaging plane; a diaphragm that can vary the amount of transmitted light disposed in the diaphragm; a light amount control means that controls the aperture amount of the diaphragm according to a signal from the photometry means; a light emission amount control means controlled by a signal from the means; a switching means for switching the light amount control state by the light amount control means during collimation observation to photographing; and a switching means for switching the aperture amount of the diaphragm to photographing according to the signal from the switching means. and a holding control means for holding the aperture in the previous state or in the further stopped-down state, and at the time of shooting, the aperture of the aperture is set in the state before switching to shooting or in the further stopped-down state. Measure the amount of light by means,
An endoscope imaging device characterized in that the amount of light emitted from a photographing lamp is controlled by the signal. 2. The endoscope imaging device according to claim 1, wherein the light emission amount control means includes a switching means that is manually operated to switch according to the sensitivity of a filter or an image sensor.