JPS6380217A - Light source unit for endoscope - Google Patents

Abstract

PURPOSE:To select an optimum illuminating state in accordance with a use state by providing a turret for positioning successively filters of each color by the rotation of a motor, on an emitting optical path, and also, providing a moving mechanism for withdrawing the turret and a filter from the emitting optical path. CONSTITUTION:The titled unit is provided with an illuminating light source 1, a turret 6 for positioning successively filters 11, 12 and 13 of each color by a rotation of a motor 8, on an emitting optical path L for sending a light beam of the illuminating light source 1, and moving mechanisms 7, 32 and 33 which can withdraw the turret 6 and the filters 11, 12 and 13 except the motor 8, from the emitting optical path L. When an image is too dark at the time of color photographing of a face sequential system, the turret 6 and the filters 11, 12 and 13 are withdrawn from its emitting optical path L by the moving mechanisms 7, 32 and 33. In such a way, in accordance with the use state, a state for executing a sequential illumination of each color by positioning the turret and the filters in the emitting optical path, and a state for executing a natural light illumination by withdrawing said turret and filters from the emitting optical path can be selected and used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light source device for an endoscope, which is used, for example, when photographing color images using a solid-state imaging device in a frame-sequential manner.

[Prior Art] In recent years, endoscopes have been known in which a solid-state imaging device such as a COD is provided at the tip of an insertion section to perform color imaging. In this case, since a solid-state image sensor such as a COD is installed in an extremely narrow space at the tip of the insertion section of the endoscope, it is impossible to increase the number of pixels. For this reason, a frame sequential method is used that effectively uses all pixels. As shown in Japanese Unexamined Patent Publication No. 59-151591, this field-sequential method uses three lights that separately transmit three colors, red (R), green (G), and blue (B), on the illumination light source side. Wheel with filter (
By rotating the turret, the illumination light is separated into each color and sequentially illuminated. As a result, a component image of each color is obtained, and the three color component signals of each pixel are combined to generate a video signal of a color image.

[Problems to be Solved by the Invention] However, in the case of the above-mentioned field sequential method, light does not pass through the entire rotation of the wheel, but there is no light during the light-blocking period between the filters of each color. Moreover, the image signals of each color are read out using this blanking period, but in order to read out accurately, the blanking period must be kept relatively long. Furthermore, when passing through each filter, only the light of that color component becomes a small amount of illumination light.

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

Incidentally, in the case of an endoscope, the illumination light is originally small because a long light guide with a small diameter is used to guide the illumination light into the observation field. Therefore, the situation where the brightness of the photographed image becomes low may become a serious problem. For example, depending on the situation inside the body cavity, the brightness of the color image may not be sufficient, making observation and diagnosis itself difficult.

The same applies when the illumination lamp burns out and is switched to a low-intensity backup lamp, so that the brightness of the illumination lamp itself becomes dim.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and provides a light source device for an endoscope that can select the optimal illumination condition depending on the usage situation and ensure a clear observation image. The purpose is to

[Means for Solving the Problems] The present invention provides an endoscope light source device that sends illumination light to an illumination light guide path of an endoscope, which includes an illumination light source and light from this illumination light source to the illumination light guide path. A turret that sequentially positions filters of each color on the output optical path by rotation of a motor, and a moving mechanism capable of retracting the turret and the filter excluding the motor from the output optical path. This is what I did.

[Function] For example, when the image is too dark in frame-sequential color photography, the movement mechanism moves the turret 6 and filter 1.
1.12.13 is evacuated from its output optical path. Thereby, the light emitted from the illumination light source 1 is directly sent to the illumination light guide path side of the endoscope to provide bright illumination.

Furthermore, since at least the turret and filter, excluding the motor, are retracted from the output optical path, the retracting operation can be performed quickly with less power.

[Example] The drawings show an example of the present invention. In the figure, 1 is a lamp as a light source for illumination. The light emitted from this lamp 1 is turned into a beam parallel to the output optical path by a condensing lens 2 in the front stage, and is further focused by a condensing lens 3 in the latter stage, after which an interline transfer type solid-state image sensor is used. The light enters an incident end surface 5 of a light guide 4 that is an illumination light guide path of an endoscope, for example, on the imaging device side.

A peripheral portion of the turret 6 is inserted between the condensing lenses 2.3 on the output light path. This turret 6 is pivotally supported by one end of a support lever 7 whose intermediate portion is pivotally supported, and is rotationally driven by a motor 8 as described later. In addition, red (R) and green (G) are concentrically arranged around the turret 6.
, blue (B) color filters 11, 12, 13 are provided discontinuously.

Furthermore, a solenoid 32 is provided at the other end of the support lever 7.
The plunger 33 is connected to the solenoid 32.
When energized, the plunger 33 is pulled and the support lever 7 is rotated, thereby retracting the turret 46 from the output light path. Further, a gear portion 34 is formed around the turret 6, and this gear portion 34 meshes with a pinion 35 set at a fixed position when the turret 6 is inserted onto the output optical path. It has become. This 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 explained. First, when photographing a color image normally, 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 light path. Therefore, when the turret 6 is rotated by the motor 8, each filter 11.12
．． 13 are sequentially located on the emitted light path, and are sequentially colored by transmitting the light from the lamp 1. The light of each color enters the light guide 4 of the endoscope from its entrance end face 5. Then, by illuminating the observation field, component images of each color are captured by the solid-state image sensor of the endoscope. Further, this imaging signal is combined with a color video signal and displayed on a monitor.

By the way, when the lamp 1 burns out and is replaced with a spare one, the brightness of the spare lamp generally becomes low and the observation field becomes dark. Furthermore, the observation field may become dark depending on the conditions of the observation field.

However, in such cases, there are times when it is desirable to brighten the observation field image for accurate diagnosis.

In such a case, the support lever 7 is rotated by energizing the solenoid 32, and the turret 6 is retracted from the output light path. Therefore, the light of the lamp 1 does not pass through the filters 11, 12, 13 and is not blocked by the members of the turret 6. Therefore, the light from the lamp 1 enters the incident end surface 5 of the light guide 4 as natural light. Therefore, the entire light amount of the lamp 1 can be used as the illumination light amount, and by brightly illuminating the observation field, the photographed image becomes bright and clear. Therefore, it does not interfere with the above diagnosis. However, since the lighting is natural light, the image at this time will be black and white rather than color.

【Effect of the invention〕

As described above, the endoscope light source device of the present invention is provided with a turret that sequentially positions filters of each color by rotation of a motor on the output optical path that sends the light from the illumination light source to the illumination light guide path, and further includes the Since a moving mechanism is provided that allows the turret and the filter, excluding the motor, to be retracted from the output optical path, the turret and filter can be positioned in the output optical path depending on the usage situation to sequentially illuminate each color. The turret and filter can be retracted from the output optical path to provide natural light illumination.

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

[Brief explanation of the drawing]

The drawing is a perspective view showing an embodiment of the present invention. 1...Lamp, 4...Light guide (lighting light guide path)
, 5... Incidence end surface, 6... Turret, 7... Support lever, 8... Motor, 11... Filter, 12
...Filter, 13...Filter, 32...Solenoid, 33...Plunger, 35...Pinion. Applicant's representative Patent attorney Atsushi Tsuboi vA5. ) Engraving (no changes in content) Figure 1

Claims (1)

[Claims] An endoscope light source device that sends illumination light to an illumination light guide path of an endoscope includes an illumination light source, an output light path that sends light from this illumination light source to the illumination light guide path of the endoscope, and this output light. A light source device for an endoscope, comprising a turret that sequentially positions filters of each color on a road by rotation of a motor, and a moving mechanism that retracts the turret and the filter excluding the motor from the output optical path. .