JPS6355332B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image monitoring device, and more particularly to an image monitoring device in which the field of view frame of an imaging section, that is, the size of the display shape of a display section is variable.

In recent years, in endoscopic observation, it has become common practice to display an optical image on an external monitor device. In this case, since the optical image inside the body cavity has different brightness between the center and the periphery, a certain shedding correction is performed. However, in endoscopic observation, the type of endoscope may be changed depending on the site to be observed, and changing the type of endoscope changes the field of view frame, resulting in a change in the size of the optical image.
Therefore, if the endoscope attached to the monitor device is changed, correct shading correction cannot be performed, and an image with uniform brightness cannot be displayed. This applies not only to endoscopes but also to monitor devices connected to other optical devices.

An object of the present invention is to provide an image monitor device that always displays an image with uniform brightness regardless of the size of the displayed image.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image monitoring device according to the present invention will be described below with reference to the drawings. here,
The case where it is connected to an endoscope will be explained. 1st
The figure is a schematic diagram thereof. The endoscope main body 10 includes a flexible section 14 that is inserted into a body cavity 12, a connecting section 18 that is connected to a light source 16, and an eyepiece section 20. A camera head 22 is connected to the eyepiece 20, and the output electrical signal of the camera head 22 is sent to the video controller 2.
4. Video controller 24 is further connected to CRT monitor 26.

FIG. 2 is a circuit diagram of this block. Eyepiece part 2
An output signal from an image pickup tube 28 that captures an optical image incident on the camera head 22 through a preamplifier 30 is supplied to a shading correction circuit 32 through a preamplifier 30. A scope type selector 34 is further provided within the camera head 22, and this selector 3
The output end of 4 is connected to a correction signal generator 36.
Further, the output terminal of the preamplifier 30 is connected to the visual field determination circuit 3.
8. It is also connected to a correction signal generator 36, and the output end of the determination circuit 38 is connected to the correction signal generator 36. A horizontal synchronizing signal generator 40 and a vertical synchronizing signal generator 42 are connected to the image pickup tube 30 and the correction signal generator 36. The output end of the correction signal generator 36 is connected to the shading correction circuit 32. Correction circuit 32
The output signals are red (R),
The signals are supplied to green (G) and blue (B) signal generators 50, 52, and 54. The output terminals of the color signal generators 50, 52, 54 are R, G, B signal correction circuits 56, 5, respectively.
8 and 60. The output end of the correction signal generator 36 is connected to the color signal correction circuits 56, 58,
60 is connected to the second input terminal. The output terminals of the color signal correction circuits 56, 58, and 60 are connected to a video signal generation circuit 62, and the output signal of the video signal generation circuit 62 is supplied to the CRT monitor 26.

Next, the operation of this embodiment will be explained. The light emitted from the light source 16 creates an optical image of the diagnostic site within the body cavity at the eyepiece 2.
The image is formed on the imaging surface of the imaging tube 28 attached to the camera. The image pickup tube 28 scans this optical image in synchronization with horizontal and vertical synchronization signals and outputs a photoelectric conversion signal.
This photoelectric conversion signal is amplified by a preamplifier 30,
A photoelectric signal as shown in FIG. 3a is obtained. Usually, the field frame of the eyepiece of an endoscope is circular, so
Among the components of each horizontal scanning period of this photoelectric signal, the component at the center of one image has the longest time width, and the components at both ends have the shortest time width. Further, when another endoscope is attached to the camera head 22, if the size of the field frame changes, the time width of the photoelectric signal component changes depending on the size. The visual field determination circuit 38 converts the photoelectric signal into a pulsed visual field signal as shown in FIG. 3b in accordance with the reference voltage _Vc . The correction signal generator 36 determines the shape of the field frame in response to the field of view signal. For example, if one image is divided into 525 horizontal scanning lines, the 1st, 132nd, 263rd, and
393, the field of view frame is determined by the pulse width of the field of view signal synchronized with the 525th vertical synchronization signal, and
A shading correction signal as shown in FIG. 1 is supplied to the shading correction circuit 32.

Here, if the scope selector 34 in the camera head 22 is switched and some signal is supplied from the selector 34 to the correction signal generator 36, the correction signal generator 36 will operate regardless of the field of view signal from the field of view determination circuit 38. , the shape of the field frame is determined by the signal from the selector 34. That is,
The shape of the field frame of the eyepiece 20 attached to the camera head 22 can be determined either automatically or manually, and the amount of shading correction can be freely set.

This shading correction signal is superimposed on the photoelectric signal in the shading correction circuit 32 during the next scan, and the corrected photoelectric signal is supplied to the color signal correction circuits 56, 58, 60 via a filter and superimposed on the shading correction signal again. and shading correction. After this, the color correction circuits 56, 58,
The output signal 60 is converted into a video signal by a video signal generation circuit 62 and displayed on a CRT monitor 26.

As described above, according to this embodiment, since the shading correction is performed according to the shape of the field frame,
An image with uniform brightness is always displayed.

A second embodiment of the invention will be described with reference to FIG. The connecting mount 64 of the eyepiece 20 is provided with a positioning groove 66 and a shorting plate 68. The connection mount 70 of the camera head 22 is provided with a pawl 72 and a plurality of contacts 74 that correspond to the positioning grooves. The other parts are the same as those in the first embodiment, so illustration is omitted.

Next, the operation of this embodiment will be explained. Eyepiece part 2
When 0 and camera head 22 are connected, contact 74
Any two of them are short-circuited by the short-circuit plate 68.
The output signal of contact 74 is supplied to visual field determination circuit 38 . Here, if the shorting plate 68 of the eyepiece 20 is provided at a position depending on the type of endoscope, that is, the shape of the field frame of the eyepiece 20, the visual field can be determined by the output signal of the contact 74. be done. Therefore, this second
In this embodiment as well, the shading correction is performed according to the field frame.

Although the above-described embodiment is a combination of an endoscope and a monitor, the present invention is not limited to endoscopes, but is equally applicable to other optical instruments having an eyepiece to which a camera head can be attached.

As explained above, according to the present invention, it is possible to provide an image monitor device that always displays an image with uniform brightness regardless of the size of the displayed image.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of an image monitoring device according to the present invention, FIG. 2 is a block circuit diagram thereof, FIGS. 3 a to c are time charts showing its operation, and FIG. 4 is a second embodiment. FIG. 20... Eyepiece section, 26... CRT monitor, 28
...Image tube, 32...Shading correction circuit,
36... Correction signal generator, 38... Visual field determination circuit, 50, 52, 54... Color signal generation circuit, 5
6, 58, 60...color signal correction circuit.

Claims (1)

[Scope of Claims] 1. An imaging means for forming an optical image of a subject within an imaging field of predetermined size, and a predetermined imaging means that is detachably connected to the imaging means and is larger than the imaging field of view. an imaging means having a field of view and photoelectrically converting an optical image within the photographing field; a determining means generating a field of view signal according to the size of the imaging field when connected to the imaging means; and the determining means An image monitoring device comprising means for correcting shading of a signal within the imaging field of view among the output signals of the imaging signal according to an output field of view signal of the imaging signal. 2. The imaging means is of a scanning type, and the determination means outputs a visual field signal only during a period in which the photoelectric conversion output signal of the imaging means is equal to or higher than a predetermined level in each horizontal scanning period. The image monitor device described in . 3. Claim 1, wherein the determining means is attached to the imaging means and has a plurality of contacts, one of which is short-circuited depending on the type of imaging means when combined with the imaging means. The image monitor device described in .