JP2000083182A - Electronic endoscope device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accelerate image quality improvement while eliminating the heating of a scope tip part, reducing power consumption and preventing noise increase. SOLUTION: In the CCD 11 of the high number of pixels, 800,000 pixels for instance, arranged at the tip of an electronic scope 1, by using the horizontal clock frequency of about 15 MHz, the image data of 15 frames (low read speed) are read in one second. The image data are tentatively stored in a frame memory 19 inside a processor 2 at the same speed. On the other hand, at the time of reading the image data from the frame memory 19, the high-speed horizontal clock frequency signals of about 60 MHz which is the quadruple of 15 MHz for instance are used and thus, the image data of 60 frames are read in one second. As a result, on the side of the electronic scope, an operation is performed at a low clock frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus, and more particularly to a configuration of a signal processing means when a solid-state image pickup device having a high number of pixels is applied.

[0002]

2. Description of the Related Art An electronic endoscope apparatus is a CCD (Charge Coupled) which is a solid-state image pickup device arranged at the tip of an electronic scope.
Device) captures an in-vivo image obtained through the objective optical system, reads out the CCD image data, and displays the in-vivo image on a monitor or the like. In the electronic endoscope apparatus, image quality has been improved from the past, and a CCD having, for example, about 400,000 pixels is currently used. The enhancement of the image quality of the endoscope image depends on the progress of the CCD manufacturing technology, but it is expected that the image quality will be further improved in the future with the emergence of the high pixel count CCD.

[0003]

However, the above C
In a CD, as the number of pixels increases, it is necessary to read out image data faster, and the higher reading speed causes problems such as the tip of the electronic scope having heat. For example, a 800,000 pixel CC which is twice the conventional 400,000 pixel
Assuming that a horizontal clock frequency of about 14.3 MHz is used for 400,000 pixels in the case of using D, a horizontal clock frequency of about 28.6 MHz is doubled for 800,000 pixels.
It is necessary to read an image signal (accumulated charge) from D.

However, when a clock frequency as high as 28.6 MHz is used, the amount of heat generated from the CCD and its surroundings increases, and the tip is disadvantageously heated. Required. In addition, when the clock frequency is high, there is a problem that power consumption increases and signal noise increases due to unnecessary radiation.

The present invention has been made in view of the above problems, and has as its object to eliminate the need for heating the distal end of a scope.
An object of the present invention is to provide an electronic endoscope apparatus capable of promoting high image quality while reducing power consumption and preventing an increase in noise.

[0006]

In order to achieve the above object, an electronic endoscope apparatus according to the present invention comprises an electronic scope having a solid-state image pickup device having a high pixel count, and an electronic scope connected to the electronic scope. And a processor device for temporarily storing the obtained image data in a memory and outputting the data of the reference number of images per unit time to the outside, and outputting a smaller number of images per unit time than the reference number of images from the solid-state imaging device. A CCD drive control circuit for reading out image data at a low readout speed, and the data provided at the low readout speed provided in the processor device and temporarily stored in the memory;
A memory control circuit for reading out image data at a high readout speed at which the reference number of images is output per unit time. In the above, the image processed per unit time may be either a field image or a frame image.

According to the above configuration, for example, when a CCD having 800,000 pixels, which is twice as many as the conventional number of pixels, is used, 1
Assuming that the number of reference (setting) images to be output per second is 60 frames (or fields), for example, about 15 M
An image of 15 frames is read out per second at a horizontal clock frequency of Hz. The image data output from the CCD (electronic scope side) at this low reading speed is temporarily written into an image memory, and thereafter, the above-described 60 frames (reference image number) at a clock frequency of about 60 MHz, which is four times the high reading speed. ) Is read out in one second.

That is, by doubling the number of images read from the memory, the CCD can operate at a low clock frequency. From a different point of view, data reading from this memory is also performed at the above clock frequency, about 15 MHz.
If an image is displayed in z, flicker will be generated, so that the occurrence of flicker can be prevented.

[0009]

1 and 2 show the configuration of an electronic endoscope apparatus according to an embodiment. As shown in FIG. 1, a CCD 11 is disposed at the tip of an electronic scope 1. Is done. As shown in FIG. 2, the CCD 11 is composed of about 800,000 pixels (the number of pixels is arbitrary) divided into, for example, 1024 in the horizontal direction and 768 in the vertical direction.
The driving is controlled by the CCD driver 12. This CCD
The driver 12 controls each control pulse (read pulse) based on a horizontal clock frequency of about 15 MHz in this example.
The image data of 15 frames is read out per second from the CCD 11 by forming and outputting the image data. In this example, all pixels in each frame are sequentially read, but image data in each field may be sequentially read by interlaced scanning.

The CCD 11 is connected to a digital signal processor (DSP) 13 for performing signal processing such as white balance and gamma correction on an image signal (video signal). The DSP 13 is, for example, a connector of the electronic scope 1. It is housed inside the unit (circuit unit). Such an electronic scope 1 is connected to the processor device 2 by the connector section.

In the processor device 2, the DSP 1
3, a mirror circuit 15 for inverting the top, bottom, left and right of the image in a predetermined direction, and a signal conversion for converting an output image signal of the CCD 11 into a luminance (Y) signal and a color difference (RY, BY) signal. A circuit 16, a superimpose circuit 17 for displaying information (patient information, etc.) relating to imaging on a screen;
A character generating circuit 18 for generating characters, symbols, etc. of information is provided for the superimposing circuit 17,
Subsequent to the superimpose circuit 17, a frame memory 19 for storing frame image data is arranged.

A memory controller 20 is connected to the frame memory 19, and a timing for forming various timing signals including a write signal and a read signal for the memory 19 by an oscillator having a predetermined frequency in the processor device 2. A generator 21 and a CPU 22 for controlling the entire apparatus are provided.

That is, in the frame memory 19, under the control of the memory controller 20, the image data output from the superimpose circuit 17 is written at a rate of 15 frames / second (sec). After that, the above CCD
Approximately 60 MHz which is 4 times the clock frequency in 11
At a high clock frequency of 60 frames per second (60 frames / sec).

Further, after the frame memory 19,
From the luminance signal (Y) and the color difference signals (RY, BY), R for forming R (red), G (green), and B (blue) signals is formed.
GB matrix circuit 25, isolation device 2
6, D / A converter 27, RS232C or ISO13
An interface unit 28 of a standard such as 94 is provided.
That is, in this example, not only the RGB signals obtained by the RGB matrix circuit 25 are output as analog signals to a monitor or the like, but also digital image signals of luminance signals and color difference signals are digitally output to a personal computer or the like via the interface unit 28. I can do it.

Further, a D / A converter 30, a color coder 31, and an isolation device 32 are also arranged at the subsequent stage of the frame memory 19, and Y (luminance) /
A C (color difference) signal and an NTSC signal can be output.

The embodiment has the above configuration. In this embodiment, as shown in FIG. 2, a CCD 1 having approximately 800,000 pixels is used.
Driving control using a horizontal clock signal having a frequency of about 15 MHz is performed by the CCD driver 12 for one, and an image of one frame is sequentially read out every 1/15 second at a low reading speed of 15 frames / sec. The image data is written to the frame memory 19 after being subjected to various kinds of signal processing through the above-described DSP 13, signal conversion circuit 16, superimpose circuit 17, and the like. That is, under the control of the memory controller 20, 15 frames / s
Frame images are sequentially written at the speed of ec.

On the other hand, in the frame memory 19, a high-speed reading control is performed by a memory controller 20 using a horizontal clock signal having a frequency of about 60 MHz, and an image of one frame is generated every 1/60 second at a rate of 60 frames / sec. Are sequentially read out, and the image data thus read out is output in various formats. That is, as described above, the signal that has passed through the RGB matrix circuit 25 is R
It is output as a GB signal (analog signal) to a monitor via a D / A converter 27, and a digital signal of a luminance and color difference signal is output from an interface circuit 28 to a personal computer or the like, and an NTSC signal ( Analog signal) is output to an NTSC television monitor.

In the above embodiment, the horizontal clock frequency is set to about 15 MHz. However, another frequency such as about 20 MHz may be used.
20 frames of image data can be read from the CD 11 per second, and the frame memory 19 can read 60 frames of image data per second by using a frequency signal of about 60 MHz, which is three times as large. Further, the memory in the processor device 2 may be a field memory.

Further, the number of pixels of the CCD 11 is 100
It may have 10,000 pixels, 1.3 million pixels, or the like, and can cope with other high-pixel CCDs by appropriately changing the clock frequency, frame rate, and the like.

[0020]

As described above, according to the present invention,
A processor device for temporarily storing image data obtained by the solid-state imaging device in a memory, and outputting data of a reference number of images per unit time to an external device; Since the image data is read at a low reading speed at which a small number of images are output, while the image data is read from the memory at a high reading speed at which the reference image number is output per unit time, the image data at the electronic scope is low. It can be operated at the clock frequency. Therefore, it is possible to promote high image quality while reducing the power consumption and preventing an increase in noise on the electronic scope side without heating the distal end of the scope by adopting a high clock frequency.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of an electronic endoscope apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing processing of image data transferred from a CCD to a frame memory in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic scope, 2 ... Processor device, 11 ... CCD, 19 ... Frame memory, 20 ... Memory controller, 21 ... Timing generator, 22 ... CPU.

Continuation of the front page F term (reference) 4C061 AA00 BB01 CC06 DD00 FF35 JJ11 JJ15 LL02 NN01 NN07 PP03 PP15 SS05 YY12 5C022 AA09 AB51 AC00 AC42 AC69 5C024 AA01 BA03 CA05 CA21 CA24 CA25 DA01 DA02 GA11 HA24 JA11 EB0504 HA12

Claims (1)

[Claims] 1. A solid-state imaging device disposed at the tip of an electronic scope, and image data obtained from the solid-state imaging device are temporarily stored, and control is performed so as to output data of a reference number of images per unit time to the outside. And a CCD drive control circuit for reading out image data at a low readout speed from the solid-state imaging device, the number of images being less than the reference number of images being output per unit time, and data obtained at the low readout speed. And a memory control circuit for temporarily storing image data in the memory, and thereafter reading out image data at a high reading speed at which the number of reference images is output per unit time.