JPH11253397A - Endoscope system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately control illumination by a light emitting diode without changing a color tone. SOLUTION: CCD output signals outputted from a pre-process circuit 12 are outputted to a brightness signal generation circuit 18 and the brightness signal generation circuit 18 generates brightness signals from a signal level. A difference between the brightness signals and brightness reference signals from a brightness reference signal generation circuit 20 is taken by a difference circuit 19 and a light emitting time control circuit 25 controls the opening/ closing time of a switch 23 so as to turn the difference between the brightness signals and the brightness reference signals by the difference circuit 19 to '0'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope apparatus, and more particularly, to an endoscope apparatus having a light emitting diode drive control section.

[0002]

2. Description of the Related Art In recent years, by inserting an elongated insertion portion into a body cavity, an organ inside the body cavity or the like can be observed with an eyepiece by an image transmission means such as an image guide, or inserted into a treatment instrument channel as necessary. Optical endoscopes capable of performing various medical treatments using the above-mentioned treatment tools, and electronic endoscopes provided with an image pickup means including a solid-state image pickup device such as a charge-coupled device (CCD) at the distal end thereof are widely used.

Conventionally, in an endoscope as described above, means for supplying illumination light include a means for inserting illumination light into an endoscope insertion portion and supplying illumination light from a light source device to the light guide. In addition, for example, JP-A-60-559
As disclosed in Japanese Patent Application Publication No. 24 and JP-A-63-309912, a light-emitting means such as a light-emitting diode is provided at the end of an endoscope, and the light-emitting means emits light.

In an endoscope provided with a light-emitting diode as a light-emitting means at the distal end, for example, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent Application Laid-Open No. 4 (1999) -2004, dimming is performed by varying the drive current of a light emitting diode.

[0005]

However, when light control is performed by varying the drive current of the light emitting diode, the spectral characteristics of the light emitting diode change, and an image having a different color tone depending on the light control level is obtained. In particular, there is a problem that diagnosis may be hindered particularly in an endoscopic image.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an endoscope apparatus capable of appropriately adjusting illumination by a light emitting diode without changing a color tone. .

[0007]

An endoscope apparatus according to the present invention comprises:
An endoscope having a light emitting diode for irradiating the subject with illumination light at the tip of the insertion portion to be inserted into the body cavity and an imaging unit for imaging the subject; and driving the light emitting diode and the imaging unit and the imaging unit. An endoscope apparatus comprising: a signal processing device that performs signal processing on the imaging signal, wherein the signal processing device includes: a brightness signal generation unit configured to generate a brightness signal of an image from the imaging signal; And a driving time control means for controlling a driving time for driving the light emitting diode in synchronization with an imaging driving signal for driving the imaging means based on the driving time.

In the endoscope apparatus according to the present invention, the driving time control means controls the light emission in synchronization with an imaging drive signal for driving the imaging means based on the brightness signal from the brightness signal generation means. By controlling the driving time for driving the diode, it is possible to appropriately adjust the illumination of the light emitting diode without changing the color tone.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 relate to a first embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of an endoscope apparatus.
FIG. 3 is an explanatory diagram for explaining the operation of the endoscope apparatus of FIG. 1.

As shown in FIG. 1, an endoscope device 1 according to the present embodiment has an RGB mosaic filter (shown in the drawing) in front of an imaging surface, for example, in the distal end of an elongated insertion portion to be inserted into a body cavity. And an electronic endoscope 3 provided with a CCD 2 having a video processor 5 for processing an image signal picked up by the electronic endoscope 3 and displaying an observed part image on a monitor 4. At the tip of the electronic endoscope 3, a white light emitting diode 6 is provided adjacent to the CCD 2 as illumination light supply means.

Then, the illumination light supplied from the white light emitting diode 6 illuminates the inside of the body cavity through the illumination lens 7, and an image of the observation site in the body cavity is reflected by the objective lens 8 through an RGB mosaic filter (not shown). Thus, an image is formed on the image forming surface of the CCD 2.

The CCD 2 is connected to a video processor 5 and receives a signal from a CCD driver 11 in the video processor 5.
When a CCD drive signal is applied to CD2,
A CCD output signal (image signal) photoelectrically converted and output by the CCD 2 is amplified by an amplifier or the like, and then output to a pre-processing circuit 12 in the video processor 5.

The CCD input to the pre-processing circuit 12
The output signal is CDS (correlated double sampling) or S / H
After preprocessing such as (sample hold) is performed, it is input to the color signal generation circuit 13 and the luminance signal generation circuit 14.

The color signal generation circuit 13 generates color difference signals RY and BY from the CCD output signal pre-processed by the pre-processing circuit 12 and performs processing such as white balance and gamma correction. The data is output to the encoder 15. In the luminance signal generation circuit 14, the CC which has been preprocessed by the preprocess circuit 12 is used.
After a luminance signal Y is generated from the D output signal and a process such as contour emphasis is performed, the superimposition circuit 16 superimposes the character signal from the character signal generation circuit 17 and outputs it to the encoder 15.

The encoder 15 converts the input color difference signals RY, BY and the luminance signal Y into a standard TV signal, for example, an NTSC signal, and causes the monitor 4 to display an image of an observation region. .

The CCD output signal output from the pre-processing circuit 12 is also output to a brightness signal generation circuit 18 for generating a brightness signal corresponding to the signal level. And a brightness reference signal from the brightness reference signal generation circuit 20.

The video processor 5 is provided with a dimming level setting switch 21. The setting value of the dimming level setting switch 21 is taken in by a controller 22, and the controller 22 changes the setting value of the dimming level setting switch 21. The brightness reference signal generation circuit 20 is controlled based on the brightness control signal, and the brightness reference signal generation circuit 20 generates a brightness reference signal corresponding to the set value of the dimming level setting switch 21.

The white light emitting diode 6 of the electronic endoscope 3
The light is emitted by the current from the constant current generating circuit 24 via the switch 23, and the switch 23 is controlled by the light emission time control circuit 25 so that the difference between the brightness signal by the difference circuit 19 and the brightness reference signal becomes zero. The opening and closing time is controlled.

The video processor 5 is provided with a reference signal generation circuit 26 controlled by the controller 22. The reference signal generation circuit 26 generates various timing signals. The CCD 2 is driven. The timing signal from the reference signal generation circuit 26 is also output to the pre-processing circuit 12, the encoder 15, and the light emission time control circuit 25.
The CD output signal (image signal) is processed based on the timing signal, and the light emission time control circuit 25 controls the open / close time of the switch 23 based on the vertical synchronization signal (VD) from the reference signal generation circuit 26. I have.

Next, the operation of the thus configured endoscope apparatus 1 of the present embodiment will be described.

The insertion portion of the electronic endoscope 3 is inserted into a body cavity,
The current from the constant current generating circuit 24 causes the white light emitting diode 6 to emit light, illuminate the inside of the body cavity, image the observation site in the body cavity by the CCD 2, and perform signal processing by the video processor 5, thereby displaying the observation site image on the monitor 4. Is displayed.

At this time, when the light control level setting switch 21 is operated, the set value of the light control level setting switch 21 is taken into the controller 22 and the brightness reference signal generation circuit 20 is operated.
, The brightness reference signal generation circuit 20 generates a brightness reference signal.

On the other hand, since the CCD output signal output from the pre-processing circuit 12 is output to the brightness signal generation circuit 18, the brightness signal generation circuit 18 generates a brightness signal from the signal level at this time. .

Then, the difference between the brightness signal and the brightness reference signal from the brightness reference signal generation circuit 20 is obtained by the difference circuit 19, and the light emission time control circuit 25 outputs the brightness signal and the brightness reference The open / close time of the switch 23 is controlled so that the difference from the signal becomes zero.

That is, when the image is dark, the dimming level is raised by the dimming level setting switch 21 and
As shown in FIG. 2B, the light emission time control circuit 25 closes the switch 23 for a time t1 from the fall of the vertical synchronization signal (VD) shown in FIG. When the image is bright, the dimming level is lowered by the dimming level setting switch 21 and FIG.
As shown in FIG. 2C, the light emission time control circuit 25 closes the switch 23 for a time t2 shorter than the time t1 to shorten the light emission time from the falling of the vertical synchronization signal (VD) shown in FIG. Dimming is performed. The driving current I of the white light emitting diode 6 at this time is constant since it is supplied from the constant current generating circuit 23.

As described above, in the present embodiment, the white light emitting diode 6 is driven by the constant drive current I by the constant current generation circuit 23, and the brightness signal and the brightness reference by the difference circuit 19 are controlled by the light emission time control circuit 25. Since the light emission is controlled by controlling the light emission time of the white light emitting diode 6 so that the difference from the signal becomes 0, the illumination by the white light emitting diode 6 can be appropriately adjusted without changing the color tone.

FIGS. 3 and 4 relate to a second embodiment of the present invention. FIG. 3 is a structural diagram showing the structure of an endoscope apparatus.
FIG. 4 is an explanatory diagram for explaining the operation of the endoscope apparatus of FIG. 3.

Since the second embodiment is almost the same as the first embodiment, only different points will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

In the video processor 5 of the present embodiment,
The color difference signals RY, RY,
RY memory 31 and BY memory 3 for storing BY
2 and a Y memory 33 for storing the luminance signal Y generated by the luminance signal generation circuit 14, and a drive current control circuit 34 capable of changing the drive current instead of the constant current generation circuit 23. Have been.

The RY memory 31, the BY memory 32, and the Y memory 33 are provided for taking in a frozen image.
Is provided with a freeze switch 35. The signal from the freeze switch 35 is captured by the controller 22, and the controller 22 controls the RY memory 31, the BY memory 32, and the Y memory 33 to display a freeze image (still image) on the monitor 4. It is made to let.

The drive current control circuit 34 receives the difference signal between the brightness signal from the difference circuit 19 and the brightness reference signal, and is controlled by the light emission time control circuit 25.

The other configuration is the same as that of the first embodiment, and the operation of this embodiment will be described next.

In this embodiment, the drive current control circuit 34
The white light emitting diode 6 is driven to emit light with the initial driving current value I from
At 1, the dimming level is increased, and after the falling of the vertical synchronizing signal (VD) shown in FIG. 4A, the light emission time control circuit 25 sets the switch 23 to the time t as shown in FIG.
(1) When the image is bright, the light control level is lowered by the light control level setting switch 21 when the image is bright. When the vertical synchronizing signal (VD) shown in FIG. As shown in FIG. 4D, the light emission time control circuit 25 performs light control with the light emission time shortened by closing the switch 23 for a time t2 shorter than the time t1, which is different from the first embodiment. In the same manner, the drive current control circuit 34 is controlled by the light emission time control circuit 25 when the desired brightness cannot be obtained when the control is performed as shown in FIGS. 4B and 4D. .

That is, even when the light emission time shown in FIG. 4B is the maximum (t1 = tmax) and the brightness cannot be increased to a desired brightness level, as shown in FIG. The control circuit 25 includes the white light emitting diode 6
While the maximum light emission time tmax is maintained, the drive current control circuit 34 is controlled to drive the white light emitting diode to emit light with the drive current value I1 (> I) larger than the initial drive current value I.

Conversely, if the light emission time shown in FIG. 4D is the minimum (t1 = tmin) and the brightness cannot be reduced to a desired brightness level, as shown in FIG. The light emission time control circuit 25 controls the drive current control circuit 34 while maintaining the minimum light emission time tmin of the white light emitting diode 6 and controls the white light emitting diode with a drive current value I2 (<I) smaller than the initial drive current value I. Drives light emission.

As described above, in this embodiment, in addition to the effects of the first embodiment, dimming is possible by controlling the drive current control circuit 34 by the light emission time control circuit 25 to make the drive current variable. Since the range can be expanded, an image having a desired brightness can be obtained. In addition, since dimming is performed by time control, a frozen image without image blur can be obtained by shortening the exposure time. .

Next, an example of mounting the white light emitting diode 6 will be described. As a first implementation example of the white light emitting diode 6, as shown in FIG.
An O-ring 64 is locked by a locking portion 63 provided between the light-emitting portion 61 and the terminal 62, and a diode-fitting portion 66 provided on the distal end portion main body 65 of the endoscope is watertight by the O-ring 64. They are fitted and electrically connected to the drive cable 67 for mounting. In this mounting example, since the white light emitting diode 6 is mounted in a watertight and fitted manner,
The white light emitting diode 6 can be easily replaced at the time of failure or the like.

As a second mounting example of the white light emitting diode 6, as shown in FIG.
A cylindrical housing 72 having a proximal end sealed therein.
A white light emitting diode body 73 is integrally incorporated therein to form the white light emitting diode 6, and a groove 75 for locking an O-ring 74
However, a screw portion 76 is formed on the outer periphery on the base end side.
Then, the housing 72 is mounted on the diode fitting portion 78 provided on the distal end main body 77 of the endoscope by watertight with an O-ring 74 and screwed with a screw portion 76. Also in this case, it is possible to easily replace the white light emitting diode 6 at the time of failure or the like.

As a third mounting example of the white light emitting diode 6, as shown in FIG. 7, for example, four white light emitting diodes 6 are provided symmetrically on the distal end face 81 of the endoscope, and the white light emitting diodes 6 are provided. Irradiation of illumination light from 6 is tilted in the radial direction with respect to the optical axis in the longitudinal direction of the endoscope of the objective lens 82 to set and mount the irradiation surface of the white light emitting diode 6. In this case, as shown in FIG. 8, the illumination range 84 can be made wider than the observation range 83.

As a fourth mounting example of the white light-emitting diode 6, as shown in FIG. 9, a white light-emitting diode 6 is formed by integrally incorporating a white light-emitting diode main body 92 into a hemispherical mounting member 91. The hemispherical mounting member 91 provided on the distal end main body 90 of the endoscope is water-tightly sealed via a rubber member 94 to a diode fitting portion 93 formed of a concave portion having the same shape as the hemispherical mounting member 91, and the hemispherical outer surface of the mounting member 91 is provided. Are mounted so as to be slidable with respect to the diode fitting portion 93, and the white light-emitting diode 6 is fixed to the diode fitting portion 93 by a front cover 95 and mounted. In this case, the hemispherical outer surface of the mounting member 91 is
3, the irradiation direction of the white light emitting diode 6 with respect to the distal end surface of the endoscope having the objective lens 101, the air supply channel 102, and the like, as shown in FIG. It is possible to set the orientation.

[Appendix] (Appendix 1) An endoscope having a light emitting diode for irradiating the subject with illumination light at the tip of an insertion portion to be inserted into a body cavity and an image pickup means for taking an image of the subject, the light emitting diode and A signal processing device that drives the imaging unit and performs signal processing on an imaging signal from the imaging unit, wherein the signal processing device generates a brightness signal of an image from the imaging signal. Signal generating means, and driving time control means for controlling a driving time for driving the light emitting diode in synchronization with an imaging driving signal for driving the imaging means based on the brightness signal. Endoscope device.

(Additional Item 2) The endoscope apparatus according to Additional Item 1, wherein the light emitting diode is a white light emitting diode.

(Additional Item 3) The endoscope apparatus according to Additional Item 1 or 2, further comprising a drive current control means for controlling a drive current of the light emitting diode.

(Additional Item 4) The driving time control means includes:
The endoscope apparatus according to claim 3, wherein the drive current control means is controlled.

[0046]

As described above, according to the endoscope apparatus of the present invention, the driving time control means converts the driving signal for driving the imaging means to the driving signal based on the brightness signal from the brightness signal generating means. Since the drive time for driving the light emitting diodes is controlled in synchronization, there is an effect that the light emitted from the light emitting diodes can be properly adjusted without changing the color tone.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of an endoscope apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining the operation of the endoscope apparatus of FIG. 1;

FIG. 3 is a configuration diagram showing a configuration of an endoscope apparatus according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram for explaining the operation of the endoscope apparatus of FIG. 3;

FIG. 5 is an explanatory diagram illustrating a first mounting example of a white light emitting diode.

FIG. 6 is an explanatory diagram illustrating a second example of mounting a white light emitting diode.

FIG. 7 is a first explanatory view illustrating a third example of mounting a white light-emitting diode.

FIG. 8 is a second explanatory diagram illustrating a third example of mounting a white light-emitting diode.

FIG. 9 is a first explanatory diagram illustrating a fourth mounting example of a white light emitting diode.

FIG. 10 is a second explanatory diagram illustrating a fourth example of mounting a white light emitting diode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope apparatus 2 ... CCD 3 ... Electronic endoscope 4 ... Monitor 5 ... Video processor 6 ... White light emitting diode 7 ... Illumination lens 8 ... Objective lens 11 ... CCD driver 12 ... Preprocessing circuit 13 ... Color signal generation circuit DESCRIPTION OF SYMBOLS 14 ... Luminance signal generation circuit 15 ... Encoder 16 ... Superposition circuit 17 ... Character signal generation circuit 18 ... Brightness signal generation circuit 19 ... Difference circuit 20 ... Brightness reference signal generation circuit 21 ... Dimming level setting switch 22 ... Controller 23 ... Switch 24: Constant current generation circuit 25: Light emission time control circuit 26: Reference signal generation circuit

Continued on the front page (72) Inventor Seiichi Higuma 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Industrial Co., Ltd. (72) Inventor Naoki Sekino 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Inside Optical Industry Co., Ltd. (72) Inventor Tomohisa Sakurai 2-43-2, Hatagaya, Shibuya-ku, Tokyo Oripus Optical Industry Co., Ltd. (72) Inventor Kenji Yoshino 2-43-2, Hatagaya, Shibuya-ku, Tokyo Ori (72) Inventor Yoshinao Daimei 2-43-2, Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd.

Claims (1)

[Claims] 1. An endoscope having a light emitting diode for irradiating a subject with illumination light at an end of an insertion portion to be inserted into a body cavity and an imaging unit for imaging the subject, and driving the light emitting diode and the imaging unit An endoscope apparatus comprising: a signal processing device that performs signal processing on an imaging signal from the imaging unit, wherein the signal processing device includes: a brightness signal generation unit configured to generate a brightness signal of an image from the imaging signal; An endoscope apparatus comprising: a drive time control unit that controls a drive time for driving the light emitting diode in synchronization with an imaging drive signal for driving the imaging unit based on the brightness signal.