JP2702165B2 - Light source device for endoscope - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope light source device capable of confirming a position of a distal end portion of an endoscope insertion portion by transmitted light outside the body.

[Problems to be solved by conventional technology and invention] In recent years, by inserting an elongated insertion portion into a body cavity,
2. Description of the Related Art An endoscope (also referred to as a scope or a fiber scope) capable of observing an organ in a body cavity or the like and performing various medical treatments using a treatment tool inserted into a treatment tool channel as necessary is widely used.

Also, various electronic scopes using a solid-state imaging device such as a charge-coupled device (CCD) as an imaging unit have been proposed.

For example, as shown in Japanese Patent Application Laid-Open No. 61-82731, a method of sequentially picking up the illumination light from R (red), G (green), and B (blue) heads is known as a field sequential method. And as shown in, for example, JP-A-60-76888,
There is a color mosaic type (also referred to as a simultaneous type) in which a filter array in which color transmission filters that transmit color lights of R, G, B, etc. are respectively arranged in a mosaic shape or the like is provided on the front surface of the solid-state imaging device.

On the other hand, when observing the inside of a body cavity with an endoscope, there is known a technique of confirming the position of the endoscope end portion by light transmitted outside the body among illumination light emitted from the endoscope end portion. However, when the position is to be confirmed by the transmitted light in this way, in the above-described surface-sequential type electronic scope, the illumination light is separated into each color light by a color separation filter. The amount of illumination decreases compared to
It may be difficult to confirm the tip position. In order to solve this problem, for example, as disclosed in Japanese Patent Application Laid-Open No. 62-2927, a technique has been disclosed in which a color separation filter is removed from the optical path even when a plane-sequential electronic scope is used to increase the amount of light.

On the other hand, in the mosaic type electronic scope, when it is difficult to recognize the position of the tip, the light amount of the light source device is semi-flashed without reducing the lamp current as shown in FIG. 5 (f).

However, as described above, the rotary filter is retracted,
When the light amount is simply increased, a large amount of illumination light is applied to the observation site in an electronic scope or a fiber scope, and the observation site may be burned out due to the heat of the illumination light. Further, in the field sequential or mosaic type electronic scope, the electric charge overflows from the CCD accumulating portion due to an increase in the amount of light, and blooming may occur, thereby deteriorating the image quality of the monitor.

The present invention has been made in view of the above points, without burning the observation site, without blooming,
An object of the present invention is to provide an endoscope light source device capable of confirming a distal end portion of an endoscope from outside the body while maintaining good image quality.

[Means and Actions for Solving the Problems] A light source device for an endoscope according to the present invention includes a normal observation mode for observing the inside of a body cavity with a normal amount of illumination light, and increasing the amount of illumination light to increase the amount of light in the body cavity at the endoscope end portion Switch means for switching between an extracorporeal light observation mode in which the position at the camera can be viewed from outside the body, light source means capable of pulse emission for supplying illumination light to an endoscope having imaging means, and extracorporeal light observation In the mode, the peak value and the pulse value of the light emission amount of the light source means are provided so that the illumination light amount has a peak value that allows the position of the endoscope tip to be visually recognized from outside the body and the cumulative illumination light amount per unit time is appropriate. Pulse light emission control means for controlling the light emission time,
A timing signal generating unit capable of outputting a timing signal corresponding to an imaging timing of the imaging unit to the pulse emission control unit, wherein when the extracorporeal light observation mode is selected by the switch unit, the pulse emission control unit The light source means is controlled to emit a pulse at a timing based on the timing signal.

Therefore, the light source device for an endoscope according to the present invention enables the normal observation mode for observing the inside of the body cavity with a normal illumination light amount, and the position in the body cavity of the endoscope distal end portion to be visually recognized from outside the body by increasing the illumination light amount. Is switched by the switch means. The light source unit supplies illumination light to the endoscope having the imaging unit by pulse emission.

Further, in the extracorporeal light observation mode, the pulse emission control means has an illumination light amount peak value that allows the position of the endoscope tip to be visually recognized from outside the body, and controls the light source so that the accumulated illumination light amount per unit time is appropriate. The peak value of the pulse light emission amount of the means and the pulse light emission time are controlled, and the timing signal generation means outputs a timing signal corresponding to the imaging timing of the imaging means to the pulse light emission control means.

When the extracorporeal light observation mode is selected by the switch unit, the pulse emission control unit controls the light source unit to emit pulse light at a timing based on the timing signal.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 to 5 relate to a first embodiment of the present invention. FIG. 1 is a block diagram showing the entire configuration of an electronic endoscope in the case of external light observation, and FIG. FIG. 3 is a block diagram of the electronic endoscope device, FIG. 3 is an overall explanatory diagram of the electronic endoscope device, FIG. 4 is an explanatory diagram of the rotary filter, and FIG. 5 is a timing chart illustrating the operation of the light source device. .

In FIG. 3, an electronic endoscope device 1 includes an endoscope 2, a light source device 3 for supplying illumination light to the endoscope 2, and an endoscope 2.
And a monitor 6 for displaying a video signal output from the control device 4 on a screen.
It is composed of

The endoscope 2 includes an elongated insertion section 7, a large-diameter operation section 8 connected to the rear end of the insertion section 7, a light guide and a signal extending from a side of the operation section 8. Cable 9
And

A rigid distal end 11 is provided on the distal end side of the insertion portion 7, and a bending portion that can be bent rearward adjacent to the distal end 11.
There are twelve. Furthermore, behind this curved portion 12,
Flexible flexible portions 13 are provided continuously. The bending portion 12,
By operating a bending operation knob 14 provided on the operation unit 8, the bending can be performed in the vertical and horizontal directions.

A light guide and signal connector 16 is provided at the rear end of the light guide and signal cable 9 so as to be connected to the light source device 3 and the control device 4 at the same time. The light source device 3 and the control device 4 are connected by a signal cable 18 provided with connectors 17 at both ends. Further, the control device 4 is connected to the monitor 6 by a signal cable 19.

The illumination light supplied from the light source device 3 is emitted forward from the distal end portion 11, and a part of the illumination light is transmitted through the inner wall 20 of the body cavity.

1 and 2, a light source unit 21 provided in the light source device 3 includes a light source lamp 22 and R (red), G (green), and B light sources.
And a rotating color filter 24 having three primary color (blue) color transmission filters 23R, 23G, and 23B. The rotary color filter 24 is driven to rotate by a motor 26 controlled by a motor control circuit 25. The illumination light emitted from the light source lamp 22 is
24. The illumination light transmitted through the rotary color filter 24 is converted into color light of each wavelength of red, green, and blue, collected by the condenser lens 28, and incident on the incident end face of the light guide 29.

The rotating color filter 24 is a color transmission filter 23R, 23G, 23B provided on the motor 26 and the rotating color filter 24.
Are provided on a rotary filter block 35 together with photosensors 30a and 30b that detect the positions of the light source lamp 22 and the light path connecting the light source lamp 22 and the incident end face of the light guide 29 by a motor movement control circuit 31. The rotating color filter 24 is inserted and removed.

The motor movement control circuit 31 is provided with, for example, a CPU 39 which receives an ON signal from an extracorporeal light observation switch 38 provided on the front of the light source device 3 and outputs a transillumination signal.
When the transillumination signal is input, the rotary color filter block 35 is removed from the optical path.

The CPU 39 is also connected to a pulse emission control circuit 41, and receives the transillumination signal. The pulse light emission control circuit 41 receives the trans-illumination signal and
A pulse signal is instructed to a lamp control circuit 42 that supplies power to the power supply, and a timing signal for controlling the timing of pulse light emission in response to a signal from the photosensors 30a and 30b is output.

In FIG. 4, the color transmission filter 23 of the rotation filter 24
The color transmission filters 23R, 23R are located on the rotation direction side of R, 23G, 23B, respectively.
Silks 43a, 43b, 43c indicating the positions of G, 23B are provided on concentric circles. Further, a start signal silk 44 is provided coaxially with the silks 43a, 43b, 43c to distinguish R, G, B of the silks 43a, 43b, 43C.

On the other hand, the light guide 29 is inserted through the endoscope 2 and can illuminate the body cavity inner wall 20 with a light distribution lens 32 disposed in front of an emission end face of the light guide 29. .

The reflected light corresponding to each of the red, green, and blue light from the inner wall 20 of the body cavity passes through an objective lens 33 provided at the distal end portion 11, and is solid-state imaging provided at an image forming position of the objective lens 33. An element (hereinafter, abbreviated as CCD) 34 receives light on an imaging surface thereof. The CCD 34 photoelectrically converts a subject image and sequentially outputs the subject image in a horizontal direction, for example, by a driving clock applied from a CCD driver 36 provided in the control device 4. The electric signal including the image information is input to a video signal processing circuit 37 in the control device 4. The video signal processing circuit 37 performs signal processing to generate a composite video signal, which is output to the monitor 6. Then, the monitor 6 displays the observation image.

The operation of the electronic endoscope apparatus 1 configured as described above will be described with reference to the timing chart of FIG.

The surgeon inserts the insertion section 7 of the endoscope 2 into a body cavity. The illumination light emitted from the light source device 3 is sequentially color-separated into R (red), G (green), and B (blue) color lights and supplied to the light guide 29. Then, the current supplied to the light source lamp 22 keeps a constant lamp current as shown in FIG. 5 (c), and the light quantity does not change. The illumination light supplied into the body cavity is reflected light
The charge enters the CCD34, accumulates the charge, and rotates the color filter 2.
The charge accumulated during the light-shielding period of 4 is the CCD driver
It is read out by the drive clock applied from 36 and output to the video signal processing circuit 37 in the control device 4. The composite video signal is output from the video signal processing circuit 37 to the monitor 6, and the subject image is displayed on the screen.

When checking the position of the distal end portion 11 during the insertion operation, the operator turns on the extracorporeal light observation switch 38 provided in the light source device 3. The ON signal is input to the CPU 39, and the CPU 39 generates a transillumination signal, and outputs this signal to the motor movement control circuit 31 and the pulse emission control circuit 41. The motor movement control circuit 31 moves the rotary filter block 35,
The rotating color filter 24 is retracted from the optical path. Note that the motor control circuit 25 also drives the rotary color filter 24 to rotate even when the rotary color filter 24 is at a position retracted from the optical path.

On the other hand, when the photo sensor 30a detects the silk 43a, 43b, 43c provided on the rotary filter 24, the output signal is set to the L level as shown in FIG. 5B. Also, the photo sensor
Fig. 30 (a) when 30b detects the start signal silk 44
As shown in FIG. Photo sensor 30a,
The output signal of 30b is sent to the pulse light emission control circuit 41, and the pulse light emission control circuit 41 determines that the L level of the photo sensor 30b immediately after the photo sensor 30a becomes L level is the color transmission filter 23R.

Upon receiving the transillumination signal, the pulse emission control circuit 41 outputs a timing signal based on the output signals of the photosensors 30a and 30b to the lamp control circuit. The lamp control circuit 42 supplies a lamp current synchronized with the timing signal as shown in FIG. This lamp current increases during the accumulation period of the CCD 34 to increase the light emission amount of the light source lamp 22, and decreases during the readout period to decrease the light emission amount.

As described above, according to this embodiment, the peak value of the illumination light is increased by increasing or decreasing the lamp current, and the transmitted light of the illumination light emitted from the outside of the body into the body cavity can be observed. In addition, the total amount of light can be suppressed to such an extent that the observation site is not burned.

Further, the pulsed light emission makes it possible to obtain a good image quality without the charges accumulated in the CCD 34 overflowing.

FIG. 6 is a timing chart for explaining the operation of the light source device according to the second embodiment of the present invention.

In this embodiment, the lamp current is increased and the current is supplied for a short time as compared with the first embodiment.

Lamp control circuit that supplies lamp current to the light source lamp 22
42 increases or decreases the lamp current in synchronization with the timing signal of the pulse emission control circuit 41 as shown in FIG. 6 (d). This lamp current increases simultaneously with the start of accumulation of the CCD 34, and decreases during the accumulation period when the accumulated charge is saturated. The current value is larger than that in FIG. 6 (c).

Because of the short irradiation time of the illumination light,
There is no occurrence of blooming due to saturation of the accumulated charge of D34. Further, although the increased lamp current is for a short period of time, the peak value of the light is high, so that the position of the tip of the endoscope can be observed from outside the body.

 Other configurations are the same as in the first embodiment.

7 and 8 relate to a third embodiment of the present invention, FIG. 7 is a block diagram illustrating the overall configuration of an electronic endoscope device, and FIG. 8 is a timing chart illustrating the operation of the light source device. FIG.

In the first embodiment, the timing signal of the pulse emission is generated from the output signal of the photosensor. In the present embodiment, this timing signal is generated from the signal output from the CCD driver.

Upon receiving the ON signal from the extracorporeal light observation switch 38, the transillumination signal output from the CPU 39 is transmitted to the motor movement control circuit 31 and the pulse emission control circuit 41.
Is also output to the motor control circuit 25. Upon receiving the transillumination signal, the motor control circuit 25 controls the motor 26 and stops the rotation of the rotary color filter 24 retracted from the optical path in accordance with an instruction from the motor movement control circuit 31.

The pulse light emission control circuit 41 is a CCD driver 3 in the control device 4
A timing signal whose falling edge is synchronized with the start of accumulation is input to the CCD 34 as shown in FIG. From this timing signal, the pulse emission control circuit 41 outputs a timing signal synchronized with the start of accumulation of the CCD 34 to the lamp control circuit 42. The lamp control circuit 42 supplies a lamp current as shown in a circuit (b) to the light source lamp 22 in synchronization with the input timing signal. This lamp current increases at the same time as the start of accumulation of the CCD 34 and decreases during the accumulation period before the accumulated charge is saturated, and the current value is larger than that in FIG. 8 (a).

With the configuration as in the present embodiment, blooming does not occur due to saturation of the accumulated charge of the CD. Further, although the increased lamp current is for a short period of time, the peak value of the light is high, so that the position of the tip of the endoscope can be observed from outside the body.

 Other configurations are the same as in the first embodiment.

9 and 10 relate to a fourth embodiment of the present invention, and FIG. 9 is a block diagram for explaining the configuration of the electronic endoscope apparatus.
FIG. 10 is a timing chart illustrating the operation of the light source device.

The present embodiment corresponds to a mosaic type imaging method.

On the imaging surface of the CCD 34 provided at the distal end of the insertion section of the endoscope 2, color transmission filters that transmit color light such as R (red), G (green), and B (blue) are arranged in a mosaic or the like. A color filter array 46 is provided. The CCD 34 is read by a drive clock applied from a CCD driver 36 provided in the control device 4 and sent to a video signal processing circuit 37 in the control device 4. In addition, the CCD driver 36 supplies a vertical synchronization signal (V, V) as shown in FIG.
D) is output to the pulse emission control circuit 41 in the light source device 3.

On the other hand, the pulse emission control circuit 41 is
, A transillumination signal generated by the CPU 39 is input. Upon receiving the transillumination signal, the pulse light emission control circuit 41 sends a timing signal to the lamp control circuit 42 based on the vertical synchronization signal. The lamp control circuit 42 supplies a lamp current as shown in FIG. This lamp current increases in synchronization with the rise of the vertical synchronizing signal, and the current value is larger than that in FIG. 10 (a).

The illumination light emitted from the light source lamp 22 is condensed by the condenser lens 28 and is irradiated on the incident end face of the light guide 29. The illuminating light is transmitted through the light guide 29 and is radiated into the body cavity by the light distribution lens 32, and a part of the illuminating light passes through the inner wall of the body cavity and reaches outside the body.

In the present embodiment, since the light amount of the light source lamp 22 is substantially the same as before transillumination as a whole, the charge accumulated in the CCD 34 does not saturate. Furthermore, there is no burning of the observation site.

Also, the pulse interval is not one shot per field, and even if it is several shots, it is sufficient that the total light quantity is not too large.

[Effects of the Invention] As described above, according to the present invention, it is possible to confirm the distal end portion of the endoscope from outside the body while maintaining good image quality without burning the observed portion and without causing blooming.

[Brief description of the drawings]

FIGS. 1 to 5 relate to a first embodiment of the present invention.
FIG. 1 is a block diagram showing the overall configuration of an electronic endoscope in the case of extracorporeal light observation, FIG. 2 is a block diagram of the electronic endoscope device in the case of normal observation, and FIG. , FIG. 4 is an explanatory view of a rotary filter, FIG. 5 is a timing chart illustrating the operation of the light source device, and FIG. 6 is related to a second embodiment of the present invention and describes the operation of the light source device. FIGS. 7 and 8 are timing charts of the third embodiment of the present invention.
7 is a block diagram illustrating the overall configuration of the electronic endoscope device, FIG. 8 is a timing chart illustrating the operation of the light source device, and FIGS. 9 and 10 are diagrams of the present invention. FIG. 9 is a block diagram illustrating the configuration of an electronic endoscope apparatus according to the fourth embodiment, and FIG. 10 is a timing chart illustrating the operation of the light source apparatus. DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope apparatus, 2 ... Endoscope 3 ... Light source apparatus, 4 ... Control apparatus 6 ... Monitor, 7 ... Insertion part 11 ... End part, 21 ... Light source part 22 ... Light source lamp 24 Rotating color filter 29 Light guide 31 Motor movement control circuit 34 Solid-state image sensor 36 CCD driver 37 Video signal processing circuit 38 External light observation switch 39 … CPU, 41 …… Pulse emission control circuit 42 …… Lamp control circuit

Claims (1)

(57) [Claims] 1. A normal observation mode for observing the inside of a body cavity with a normal amount of illumination light, and an extracorporeal light observation mode for increasing the amount of illumination light so that the position of the distal end of the endoscope in the body cavity can be visually recognized from outside the body. Switch means for switching, light source means capable of pulse emission for supplying illumination light to the endoscope having imaging means, and the position of the endoscope distal end portion can be visually recognized from outside the body in the extracorporeal light observation mode A pulse light emission control unit having a peak value of an illumination light amount and controlling a peak value and a pulse light emission time of a pulse light emission amount of the light source unit so that an accumulated illumination light amount per unit time is appropriate; A timing signal generating means capable of outputting a timing signal corresponding to the imaging timing of the means to the pulse emission control means, and when the extracorporeal light observation mode is selected by the switch means, Serial light source device for an endoscope and controls so allowed to pulse emitting the light source means by the pulse light emission control means at a timing based on said timing signal.