JPH0664247B2 - Light source device for endoscope - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device for an endoscope, which is used when an image is captured by a solid-state image sensor in a frame sequential method.

[Prior Art] In recent years, it is known that a solid-state imaging device such as a CCD is provided at the tip of an insertion portion of an endoscope to perform color imaging. In this case, since a solid-state image sensor such as a CCD is incorporated in an extremely narrow space such as the tip of the insertion portion of the endoscope, the number of pixels cannot be increased. For this reason, a frame sequential method is used in which all pixels can be effectively used. In addition, as shown in Japanese Patent Laid-Open No. 59-151591, this frame-sequential system uses three illumination light sources to separately transmit three colors of red (R), green (G), and blue (B). By rotating a wheel (turret) provided with a filter, the illumination light of each color is decomposed and sequentially illuminated. In this way, the component image of each color is obtained, and the component signals of the three colors for each pixel are combined to generate the video signal of the color image.

[Problems to be Solved by the Invention] However, in the case of the frame sequential method, light is not transmitted during all the periods during rotation of the wheel, and there is no light during the light-shielding period between the filters of each color. Moreover, the blanking period is used to read out the image signal of each color, but the blanking period must be ensured to be relatively long in order to perform the reading accurately. Further, when passing through each filter, only a small amount of illumination light of that color component is emitted.

As described above, the above-described method has an essential drawback that the illumination light from the light source lamp cannot be effectively used and the brightness of the color image is relatively low.

By the way, in the case of an endoscope, the illumination light is originally small because the illumination light is guided to the observation visual field by using a long and thin light guide. Therefore, the situation where the brightness of the captured image is low may be a serious problem. For example, the brightness of the color image is not sufficient depending on the condition inside the body cavity, and the observation diagnosis itself may be difficult.
Moreover, since the examination lamp is burnt out and switched to a low-intensity auxiliary lamp, the same applies when the examination lamp itself becomes dark.

[Object of the Invention] The present invention has been made in view of the above problems, and provides a light source device for an endoscope, which can select an optimal illumination state according to the use situation and can secure a clear observation image. The purpose is to

[Means for Solving the Problems] The present invention relates to an endoscope light source device that sends illumination light to an illumination light guide path of an endoscope that sequentially captures component images of respective colors by a frame sequential method. An output light path for sending light from the illumination light source to the illumination light guide path of the endoscope, a turret provided with a plurality of rotatably provided filters for obtaining component images of respective colors on the output light path, A turret rotating means for constantly rotating the turret during imaging of the endoscope, and a moving mechanism for retracting the turret and the filter excluding the turret rotating means from the emission optical path.

[Operation] For example, when an image is too dark in the frame sequential color imaging, the turret 6 and the filter 1 are moved by the moving mechanism.
1, 12, 13 are retracted from the outgoing optical path L. As a result, the light emitted from the illumination light source 1 is sent to the illumination light guide path side of the endoscope as it is for bright illumination.

Moreover, since at least the turret and the filter, excluding the motor, are retracted from the outgoing optical path, the retracting operation can be quickly performed with a small amount of power.

[Embodiment] The drawings show an embodiment of the present invention. In the figure, 1 is a lamp as a light source for illumination. The light emitted from the lamp 1 is converted into a luminous flux parallel to the emission optical path L by the condenser lens 2 in the front stage, and is further focused by the condenser lens 3 in the rear stage, and then the interline transfer type solid-state imaging device is used. The light is incident on the incident end surface 5 of the light guide 4 which is the illumination light guide path of the endoscope, for example, on the side of the photographing device.
A peripheral portion of the turret 6 is inserted between the condenser lenses 2 and 3 in the emission optical path L. The turret 6 is rotatably supported by one end of a support lever 7 rotatably supporting an intermediate portion thereof, and is rotationally driven by a motor 8 as described later. Further, filters 11, 12, and 13 of red (R), green (G), and blue (B) colors are concentrically provided on the peripheral portion of the turret 6 in a discontinuous manner.

Further, the solenoid 32 is provided at the other end of the support lever 7.
Of the solenoid 32.
Is excited, the plunger 33 is pulled and the support lever 7 is rotated to retract the turret 6 from the outgoing optical path L. Further, a gear portion 34 is formed on the peripheral portion of the turret 6, and the gear portion 34 meshes with the pinion 35 set at the fixed position when the turret 6 is positioned on the emission optical path L. It has become. The pinion 35 is driven by the motor 8. The turret 6 can be rotated by driving the pinion 35 with the motor 8.

Next, the operation of this embodiment will be described. First, when a color image is normally taken, the turret 6 is advanced to the position shown in the drawing. As a result, the peripheral portion of the turret 6 is located on the outgoing optical path L. Then, when the turret 6 is rotated by the motor 8, each of the filters 11, 1 is rotated.
2 and 13 are sequentially positioned on the emission optical path L, and the light from the lamp 1 is transmitted to sequentially color the light. The light of each color enters the light guide 4 of the endoscope from the incident end surface 5 thereof. Then, by illuminating the observation visual field, the component image of each color is captured by the solid-state image sensor of the endoscope. The image pickup signal is combined with the color video signal and displayed on the monitor.

By the way, when the lamp 1 is burnt out and replaced with a spare lamp, the brightness of the spare lamp is generally low and the observation field of view becomes dark. Further, the observation visual field may become dark depending on the situation of the observation visual field. However, in such a case, there is a case where it is desired to make the observation visual field image bright for observation in order to make an accurate diagnosis. In such a case, the support lever 7 is rotated by exciting the solenoid 32, and the turret 6
Is retracted from the outgoing optical path L. Therefore, the light of the lamp 1 does not pass through the filters 11, 12 and 13 and is not blocked by the member of the turret 6. Therefore, the light of the lamp 1 enters the incident end surface 5 of the light guide 4 as natural light. Therefore, the total amount of light of the lamp 1 can be used as the amount of illumination light, and by illuminating the observation field of view brightly, the captured image becomes bright and clear. Therefore, the above diagnosis is not hindered. However, since the illumination is by natural light, the image at this time is not a color but a black and white one.

EFFECTS OF THE INVENTION As described above, the endoscope light source device of the present invention includes the turret that sequentially positions the filters of the respective colors by the rotation of the motor on the emission optical path that sends the light of the illumination light source to the illumination light guide path. Furthermore, since a moving mechanism that can retract the turret and the filter excluding the motor from the emission optical path is provided, the turret and the filter are positioned in the emission optical path according to the usage conditions, and the respective colors are sequentially arranged. It is possible to select and use the state of performing illumination and the state of performing natural light illumination by retracting the turret and filter from the outgoing optical path.

Further, since the turret and the filter are generally retracted from the outgoing optical path except for the motor having a large inertia, a large motive power is not required and a switching operation with a good responsiveness can be performed.

Furthermore, by retracting the turret from the exit optical path, the light of the illumination light source is natural light and can enter the front light guide path of the endoscope, so that not only a frame-sequential endoscope, The light source device for an endoscope of the present invention can be used for a simultaneous endoscope and the like.

Moreover, the turret rotation means is installed on the main body side of the endoscope light source device, and when the turret retracts from the illumination light guide path, the turret rotation means does not move together with them, so the turret The part becomes lightweight, and the moving means can be downsized. Further, it is not necessary to make the electric cable to the turret rotating means movable, and it is possible to obtain a special effect such that the endoscope light source device is not complicated.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention. 1 ... Lamp, 4 ... Light guide (illumination light guide path), 5 ... Incident end face, 6 ... Turret, 7 ... Support lever, 8 ... Motor, 11 ... Filter, 12 ... Filter, 13 ... Filter, 32 ... Solenoid, 33 ... Plungeer, 35 ... Pinion.

Claims (1)

[Claims] 1. An endoscope light source device for sending illumination light to an illumination light guide path of an endoscope for sequentially capturing component images of respective colors in a frame-sequential system, wherein the illumination light source and the light from the illumination light source are An emission light path to be sent to the illumination light guide path of the endoscope, a turret provided with a plurality of rotatably provided filters for obtaining component images of respective colors on the emission light path, and this turret is always used when the endoscope is imaged. A light source device for an endoscope, comprising: a turret rotating means for rotating; and a moving mechanism for retracting the turret and the filter excluding the turret rotating means from the emission optical path.