JPS6148333A - Endoscope photographing apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an endoscopic imaging device that takes images inside a body cavity.

[Subordinate Rice Techniques]

2. Description of the Related Art Endoscopic imaging devices have been developed in which a solid-state imaging device such as a COD is disposed at the tip of an endoscope body to take images of the inside of a body cavity, and diagnosis is performed by viewing the images displayed on a monitor device. in general,
Images are required to be able to cover a wide range from bright to dark areas, that is, to have a wide dynamic range, and to be able to recognize subtle differences in brightness, that is, to have good contrast. However, these two
C as a monitor device achieves two things at the same time.
This is difficult due to limitations such as the dynamic range of the RT display itself, and in conventional endoscopic imaging devices, adjustment has only been made by changing the amount of illumination light.

By the way, in endoscopic diagnosis, the required contrast differs depending on the region. The primary purpose of colon examination is to check for the presence or absence of elevated lesions. Furthermore, the large intestine has a narrow lumen and many folds. Therefore, if the contrast is increased to create an extreme difference in brightness and darkness within a single screen, the bright 88 minutes will stand out, tiring the eyes, and lesions in dark areas will be easily overlooked. Therefore, when diagnosing the large intestine, it is better to have a low contrast.On the other hand, when examining the stomach, the primary purpose is to check for the presence of minute redness and the shape of ulcers. Furthermore, the stomach has fewer irregularities and raised lesions than the large intestine. Therefore, high contrast is required in stomach diagnosis. Such conflicting demands cannot be resolved simply by changing the amount of illumination light as in the past.

〔the purpose〕

The present invention has been made to address the above-mentioned problems, and its purpose is to provide an inner and mirror imaging device that can obtain an image with optimal contrast depending on the region to be photographed.

〔overview〕

This purpose is achieved by amplifying the image signal with nonlinear amplification factor characteristics depending on the type of endoscope.

〔Example〕

An embodiment of an endoscope imaging device according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of this embodiment. Endoscope body 10 or light source unit 12
The illumination light from the light source unit 12 is irradiated into the body cavity via the light guide 14. The reflected light from inside the body cavity is incident on the objective, and an image of the inside of the body cavity is taken. The parts of the endoscope body are determined depending on the model, such as large intestine, blue, etc. The endoscope body is also provided with a specific resistance 20 having a resistance value depending on the model.

A video processor 22 is connected to the endoscope main body lO, and the output image signal of the solid-state image sensor 18 is transmitted to the video processor 22.
The video processing circuit 24 in the video processing circuit 24 in FIG. The output No. 4g of the video process circuit 24 is the contrast adjustment circuit 26.
is supplied to A resistor 20 is connected to a discrimination circuit 28 within the video processor 22 . The discrimination circuit 28 discriminates the model 4jj according to the resistance value of the specific resistor 20, and converts the identification signal representing the model into a contrast:g! It is supplied to the adjustment circuit 26. The contrast adjustment circuit 26 is composed of a nonlinear amplification circuit whose input/output characteristics change according to this identification signal and nonlinearly amplifies the output signal of the video processing circuit 24. The output signal of the contrast adjustment circuit 26 is supplied to a monitor device 30. A manual model selection switch 32 is connected to the contrast adjustment circuit 26 in case an endoscope main body not provided with the resistor 20 is used.

There are two types of amplification factor (input/output) characteristics of the contrast adjustment circuit 26, as shown by a broken line and a dashed line in FIG. 2, and one of them is selected depending on the model of the endoscope. The characteristic shown by the solid line is the characteristic of normal gamma correction in a CRT display. Here, it is assumed that there are two types of endoscopes: one for the large intestine and one for the blue endoscope.

The characteristics shown by the broken line are the characteristics of the endoscope for blue, and contrast is increased by lowering the gain in dark areas and increasing the gain in bright areas. On the other hand, the characteristics of the endoscope for the large intestine shown by the dashed-dotted line are such that the gain in the dark area is lowered and the gain in the bright area is lowered to reduce the contrast. However, in both cases, the dynamic range is fully utilized, and both very bright and very dark areas can be observed. The discrimination circuit 28 supplies the contrast adjustment circuit 26 with an identification signal for selecting one of the characteristics according to the resistance value of the specific resistance 20 of the connected endoscope main body 10, and the output of the video processing circuit 24 is The signal is nonlinearly amplified depending on the model of the mirror body and is supplied to the monitor device 30. In this way, the contrast adjustment circuit 24 adjusts the contrast of the image signal depending on the region to be imaged.

As explained above, according to this embodiment, when the endoscope main body is connected, the model of the endoscope main body is automatically determined,
Since the image signal is non-linearly amplified with an amplification factor depending on the model, it is possible to automatically obtain an image with the optimum contrast depending on the region to be imaged.

Note that when using an endoscope body that is not provided with the specific resistance 20, a similar contrast adjustment can be performed by manually inputting an identification signal representing the model to the contrast adjustment circuit 26 using the model selection switch 32. be done.

The present invention is not limited to the embodiments described above, and can be modified in various ways. For example, the solid-state image sensor 18 may not be built into the end of the endoscope, but may be attached to the eyepiece of a conventional endoscope having an image guide. When attached to the eyepiece of an endoscope, an image pickup tube may be used instead of a solid-state image sensor, and the video processor 22 and light source unit 12 may be integrated. Also,
Although the contrast adjustment described above does not involve normal gamma correction, if there is a normal gamma correction circuit at the subsequent stage of this contrast adjustment circuit 24, the overall input/output characteristics of this contrast adjustment circuit 24 and gamma correction circuit will change. The characteristics of the contrast adjustment circuit 24 are determined so as to have the characteristics shown in FIG. There may be more types of endoscopes than just two types.

〔Effect of the invention〕

As described above, according to the present invention, there is provided an endoscopic imaging device that can obtain an image with optimal contrast depending on the region to be imaged by nonlinearly varying the image signal depending on the type of endoscope. Ru.

[Brief explanation of drawings]

FIG. 1 is a two-dimensional diagram showing the configuration of an embodiment of an endoscope imaging apparatus according to the present invention, and FIG. 2 is a diagram showing the input/output characteristics of the contrast adjustment circuit. 12... Light source unit 16... Objective lens 18... Solid-state image sensor 20... Specific resistance 24... Video process circuit 26... Contrast adjustment circuit 28... Discrimination circuit 30... Monitor Device

Claims (1)

[Claims] In an endoscope imaging device that is detachably connected to an endoscope body inserted into a body cavity, there is a means for determining the model of the connected endoscope body, and a means for determining the model of the connected endoscope body, and a means for determining the type of image according to the output of the determination means. An endoscopic imaging device characterized by comprising means for adjusting contrast.