JPH02174490A - Picture processing unit - Google Patents

Abstract

PURPOSE:To decrease number of transmission lines by allowing a picture processing means to insert a color signal obtained from an output signal of a pickup means to a nonsignal period of a luminance signal obtained from an output signal of the pickup means and to make the luminance signal and the chrominance signal a sequential signal. CONSTITUTION:Sequential processing color difference signals R-Y, B-Y outputted from a high luminance coloring prevention circuit 42 are converted into a digital signal by an A/D converter 47. The digitized color difference signal is inputted to a FIFO memory 48 sequentially timewise by a write pulse. Then the signal is read at a speed twice that of a write with a readout pulse when the picture output period is finished. The signal is converted into an analog signal by a D/A converter 49, added to a luminance signal Y by an adder 51, then the color difference signals R-Y, B-Y are inserted to a nonsignal period other than a picture output period of the luminance signal. The added luminance and color difference signals send the signal to a secondary circuit via an isolation circuit 52.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides an imaging means for converting optical information into an electrical signal, and a video signal 51 for processing the electrical signal of the imaging means into a video signal. I
The present invention relates to an image processing apparatus having a processing means.

[Prior art and problems to be solved by the invention 1 Conventionally, an image processing device using a solid-state image sensor processes the electric signal received from the solid-state image sensor in a video signal processing circuit, and processes the color difference signal and luminance. These signals were transmitted through three transmission lines (transmission means).

However, there are cases where it is desired to reduce the number of transmission paths. For example, in an image processing device with multiple transmission paths, if it is necessary to isolate the patient side and the secondary circuit side as a measure to prevent electric shock, such as in an electronic endoscope, each transmission path must be isolated. Since an isolation means is required, which causes an increase in cost, it is necessary to reduce the number of transmission lines.

Reducing the number of transmission paths in this way leads to a reduction in the number of isolation means installed, which has the effect of reducing the cost of the image processing apparatus.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image processing device with fewer transmission paths.

[Means and Means for Solving the Problems] The image processing apparatus of the present invention causes the image processing means to receive the color signal obtained from the output signal of the imaging means during the no-signal period of the luminance signal obtained from the output signal of the imaging means. The apparatus is equipped with a sequential means for inserting a luminance signal and a color signal into sequential signals.

In the present invention, the image processing means has a sequential means, and this sequential means inserts the color signal obtained from the output signal of the imaging means into the no-signal period of the luminance signal obtained from the output signal of the fi image processing means. The luminance signal and color signal are sequentially converted into signals.

[Example] Hereinafter, an example of the present invention will be specifically described with reference to the drawings.

FIGS. 1 to 5 relate to the first embodiment of the present invention.
The figure is a block diagram explaining the configuration of the endoscope device, FIG. 2 is a timing chart explaining the operation, FIG. 3 is an illustration of the color filter array, FIG. 4 is an illustration of the display image on the monitor, FIG. 5 is an overall configuration diagram of the endoscope device.

In this embodiment, the present invention is applied to an endoscope apparatus.

In FIG. 5, an endoscope device 1 includes an endoscope 2, a light source device 3 that supplies illumination light to the endoscope 2, and a camera control unit (hereinafter referred to as (abbreviated as CCU) 4, and a monitor 6 that receives video signals output from the CCtJ 4 and displays an endoscopic image on a screen.

The family gift 1t2 includes an elongated insertion section 7, a large-diameter operation section 8 connected to the rear end of the insertion section 7, and a light guide and signal cable extending from the side of the operation section 8. 9.

A hard tip portion 11 is provided on the distal end side of the insertion portion 7, and a bendable bending portion 12 is provided on the rear side adjacent to the tip waste portion 11. Further, a flexible soft part 13 is connected to the rear of the curved part 12. The bending section 12 can be bent in the vertical/horizontal direction by operating a bending operation knob 14 provided on the operation section 8.

A light guide and signal connector 16 is provided at the rear end of the light guide and signal cable 9,
It is designed to be connected to the optical M device @3 and CCtJ4 at the same time. The light source device 3 and the CCL 14 are connected by a signal cable 18 having connectors 17 at both ends. Further, the CCU 4 is connected to the monitor 6 by a signal cable 19.

In FIG. 1, an imaging optical system 21 is provided on the distal end side of the insertion section 7. At the imaging position of the imaging optical system 21, a solid-state imaging device (hereinafter abbreviated as CCD) 20 as an imaging means is provided. The imaging surface of this C0D20 has yellow (Ye: transmits R and G), magenta (MQ: transmits R and 8), cyan (Cy: transmits B and G) as shown in Figure 3. A color filter array 22 is attached in which color separation filters of each complementary color system are provided in a mosaic pattern.

Furthermore, a light guide 23 formed of a fiber bundle that transmits illumination light is inserted into the insertion portion 7, and this light guide 23 transmits the illumination light supplied from the light source device 3, and has an output end face. The radiation is emitted from the insertion section 7.
A subject 26 is illuminated by a light distributing lens system 24 provided at the tip side of the lens.

The light source device 3 that supplies illumination light to the end surface of the light guide 23 on the proximal side is composed of a light source lamp 27 and a condenser lens 28 that condenses and irradiates the illumination light of the light source lamp 27 onto the end surface of the light guide 23. ing.

The image of the object 26 illuminated by the illumination light is color-separated by the color filter array 22 and focused by the imaging optical system 21 onto the m image plane of the C0D 20. The image of the subject 26 formed on the imaging surface of the CCD 20 is photoelectrically converted and read out as an electrical signal by applying a drive pulse from a drive pulse generator 29. Note that the drive pulse generator 29 receives a pulse signal from the pulse generator 31 and generates a drive pulse. The electrical signal containing the read video information is input to a noise reduction circuit 33 such as a correlated double sampling circuit in the CCU 4 through a signal transmission cable 32 inserted through the insertion section 7. The noise reduction circuit 33 performs double sampling using the sampling pulse output from the pulse generator 31 to produce a signal with improved S/N ratio. This signal is branched, one of which is set to the optimum γ value by the γ correction circuit 34 and input to the luminance color separation circuit 36. When this manually generated signal is output from a CCD 20 having a color filter 22, it is in the form of a signal in which a luminance signal Y is multiplexed with a color signal. In the luminance color separation circuit 36, a low pass filter (
Hereinafter, it will be abbreviated as LPF. ) 37, the luminance signal Y is divided by w1 and output. Further, the signal input to the luminance color separation circuit 36 is simultaneously filtered through a band pass filter (hereinafter referred to as BP).
It is abbreviated as F. ) 38, the color components are separated by the detector 3.
9 and is demodulated by a color demodulation pulse output from the pulse generator 31.

When the color filter array 22 is arranged as shown in FIG. 3, the color signals outputted from the detector 39 are R-Y, B.
-Y becomes a signal equivalent to a signal in which the color difference signal is sequentialized every horizontal line period.

That is, in FIG. 3, two lines are read out simultaneously for one line, and in an odd field, n
and (n+1) rows are simultaneously read out, and the upper and lower pixel information are mixed and output. In the even field, the (n+1) and n+2 (n+2) rows in the figure are simultaneously read out, and the upper and lower pixels are mixed and output. Explaining in terms of odd fields, in a line where n and n+i rows are mixed, the signal obtained by adding each pixel, that is, Mg+CV+G+Ye -R+B+B+G10+R1G -2R+3G+2B, equivalently becomes the luminance signal Y, and the signal between adjacent pixels The signal obtained by subtracting , that is, (MQ10V)-(G+Ye) = (R+B10B+G)-(G0R1G>28-G, equivalently becomes the color difference signal 8-Y.

In addition, in the line where n+2 and n+3 rows are mixed, the signal obtained by adding each pixel is Ma+Cy1G+Ye -R+B+B+G+G+R+G =28+3G+2B, which equivalently becomes the luminance signal Y in the same way as the line where n and n+1 rows are mixed, and the adjacent By subtracting the matching pixels, the signal (Ma+Ye)-(G+Cy)-(R+B+R+G)-(G+8-)-G)=2R-G equivalently becomes the color difference signal R-Y.

Note that the luminance/color separation circuit 36 may use a sampling circuit.

Color difference signals R-Y and B output from the luminance color separation circuit 36
-Y are sequentially arranged in a white balance circuit 41 and white balance adjustment is performed on each of them. Color difference signals R-Y and B-Y output from this white balance circuit 41
is sent to the high-intensity coloring prevention circuit 42. This high-brightness coloring prevention circuit 42 has a color filter array 22 attached to the C0D 20, and since the brightness levels at which pixels are saturated for each color are different, γ correction is performed to prevent white balance from being disrupted and coloring to occur. The color difference signal level of the part where the white balance of the color difference signal is disrupted is attenuated by the signal whose color signal component is removed by the LPF 37 from the output signal of the noise reduction circuit 33, which is not generated. The sequential color difference signals R-Y/B-Y outputted from the high brightness coloring prevention circuit 42 are transmitted to the sequential means 4.
3 is input.

Here, the solid-state image sensor in an electronic endoscope is small, and in order to display various data on one screen, the endoscope
A display image 44 displaying um is a part of the display screen 46 of the monitor 6, as shown in FIG. For example, the T4 degree signal Y output from the luminance color separation circuit 36 and the sequential color difference signal R-Y/B-Y output from the luminance coloring prevention circuit 42
When expressed in H rate, it becomes as shown in FIGS. 2(a) and 2(b), for example. This image output period is usually about 60% of the period excluding the blanking period from the 1H period.

Returning to FIG. 1, the sequential color difference signal R-Y/B-Y output from the high brightness coloring prevention circuit 42 is converted into a digital signal by an A/D converter 47. The color difference signal R-Y/B-Y converted into a digital signal is input to a FIFO (first-in-first-out) memory 48 from which input data can be read out at any timing.

The input/output timing of this FIFO memory 48 is shown in Figure 2 (
c), (d), and (e) show the timing of the write pulse of the FIFO memory 48 in (C), the timing of the read pulse of the FIFO memory 48, (d) of the same figure,
FIG. 4(e) shows the color difference signal output from the FIFO memory 48. The digitized color difference signals R-Y/B-Y are input to the FIFO memory 48 in time order by write pulses. Then, at the end of the image output period, reading is performed at twice the writing speed using a read pulse. The read output signal of the FIFO memory 48 is shown in the same figure (e).
It is a digital signal with a waveform not shown in .

When this signal is returned to an analog signal by the D/A converter 49 and added to the luminance signal Y by the adder 51, as shown in FIG. The waveform has signals R-Y/B-Y inserted therein.

Note that the serialization means 43 includes an A/D converter 47 and an FIF.
It is composed of an O memory 48, a D/A converter 49, and an adder 51.

The summed luminance/color difference synchronized signal is input to an isolation circuit 52 such as a transformer, and the patient circuit at the stage before this isolation circuit 52 is isolated from the secondary circuit at the stage after it. It has become.

Here, since the color difference signal R-Y/B-Y is read out at twice the speed of writing, the band is twice the band of the color difference signal before A/D conversion.

However, the band of color difference signal R-Y/B-Y is 0°5H.
tlz~1 MHz, which is about 1/4 of the luminance signal band, so the output of the adder 51 is below the luminance signal band, and the isolation circuit 52 can transmit the signal to the secondary circuit side.

On the secondary circuit side, the luminance/color difference sequential signals are branched, one is delayed for one day by a one-day delay line 53, and the other is digitized by an A/D converter 54 again. The digitized signal is input to the FIFO memory 56, and the FIFO memory 56 is configured to input the signal as shown in FIG.
Only the color difference signal is written at the timing of h), and 1/1 of the writing is done at the timing of the luminance signal of the daily delay line 53.
The data is read out at a speed of 2 as shown in (i) of the same figure. This FI
The output signal of the FO memory 56 is converted into an analog signal by a D/A converter 57, and is input to a masking circuit 58 together with the output signal of the one-day delay line 53. The masking circuit 58 removes the color difference component contained in the signal from the one-day delay line 53, and masks the area other than the effective image portion. The signal from the masking circuit 58 is input to the post-processing circuit 59, but this signal is once input to the luminance signal Y, which is the output of the color separation circuit 36 in the patient circuit, and the high-intensity coloring prevention circuit 4.
It becomes a signal equivalent to the color difference signal R-Y/B-Y which is the output of No.2.

On the other hand, the pulse generator 31 on the patient circuit side generates a timing pulse for the secondary circuit, which is also sent to the secondary circuit side by the pulse isolation circuit 61, inputted to the pulse generator 62 on the second circuit side, and then sent to the patient circuit. The timing pulses synchronized with the side are input to an A/D converter 54, a FIFO memory 56, a D/A converter 57, a masking circuit 58, and a post-processing circuit 59.

The signal inputted to the post-processing circuit 59 is synchronized by a synchronization circuit (not shown) using a timing pulse from a pulse generator 62, and various signal processing is performed together with the luminance signal Y, such as NTSC or RGB 3.
The signal is converted into a video signal such as a primary color signal and output to the monitor 6, and the monitor 6 displays an image of the subject 26.

In the above embodiment, since the color difference signals R-Y and B-Y are inserted into the no-signal period other than the image output period of the luminance signal Y,
The number of transmission lines for transmitting signals can be reduced to one, and further,
By using only one signal isolation circuit, only one signal isolation circuit can be used for the luminance signal and the color difference signal.

In this embodiment, a CCD 20 having a filter array 22 as shown in FIG. 3 has been described, but an X-Y addressing type solid-state imaging device such as an MO8 type imaging device may also be used. In that case, since each pixel output is independently obtained in the baseband, the fl Iff color separation circuit becomes a matrix circuit that performs calculations for each color after each hour. In this case as well, the method of processing the luminance signal and the sequential color difference signals is the same as in this embodiment.

Further, the filter arrangement of the color filter array is not limited to that shown in FIG. 3, and the color filter array may have any filter arrangement as long as the color signals are output as sequential signals.

FIG. 6 is a block diagram showing a modification of the first embodiment.

In this modification, an image memory for recording video signals is provided on the secondary circuit side.

In the figure, the stage before the isolation path 52 is the first
This is similar to the example. The luminance/color difference synchronized signal transmitted by the isolation circuit 52 is sent to an A/D converter 63.
is converted into a digital signal by This digital signal is input to the image memory 64 and stored. in this case,
As shown in FIG. 2(f), since a luminance signal and a color difference signal exist within the 1H period, the image signal is processed in the same manner as a frame memory or field memory that normally stores a luminance signal or a color difference signal. and color difference signals can be stored. Therefore, the memory that normally requires two systems, one for luminance and one for color difference, can be reduced to one system.
Furthermore, since there is only one system for driving the memory, the circuit is simplified. The signal read out from the image memory 64 is digitally processed by a time alignment circuit 66 to align the luminance signal and the color difference signal in the same way as in the first embodiment.
The signals are converted into analog signals by D/A converters 67 and 68, input to a post-processing circuit 59, subjected to predetermined processing, and output. In this case, as shown in FIG. 2(j), depending on the dynamic range of the image memory 64, a setup is added to the color difference signal in the adder 51, for example.
This may be stored.

7 and 8 relate to a second embodiment of the present invention, FIG. 7 is a block diagram of the endoscope apparatus, and FIG. 8 is a timing chart diagram explaining the operation.

This embodiment is for a case where the output image signal period of C0D20 is 50% or less of the period excluding the blanking period from the 1H period.

In this embodiment, the structure of the stage preceding the luminance coloring prevention circuit 42 is the same as that of the first embodiment, and the same reference numerals are given to the parts having the same function, and the explanation thereof will be omitted.

The color difference signal R-Y/B-Y output from the high-intensity coloring prevention circuit 42 shown in FIG. This delayed color difference signal R-Y/B-Y is added by the adder 51 to the luminance signal Y shown in FIG. Indicating brightness/
The color difference sequential signal is inputted to the isolator circuit 52 and transmitted to the secondary circuit side.

In this embodiment, the serialization means 43 is composed of a 1/2H delay line 71 and an adder 51.

On the secondary circuit side, a luminance/color difference sequential signal as shown in FIG. 8(d) is input to a 1-day delay line 72 and a 1/2H delay line 73. For the output of the 1-day delay line 72, the luminance signal has the normal timing, and for the output of the 1/2H delay line 73, the color difference signal has the normal timing. Unnecessary portions of these signals are masked by a masking circuit 58, and the signals are input to a post-processing circuit 59, subjected to predetermined processing, and output.

By configuring as described above, the luminance signal and the color difference signal can be easily sequentialized, and the isolation circuit and the storage circuit can be simplified.

In this embodiment, since the output image signal period of C0D20 is less than 50% of the period excluding the blanking period from the 1H period, there is no need to compress the color difference signal as in the first embodiment. Line 71 can be used. Therefore, costs can be further reduced.

Although each of the above embodiments has been explained simply as an isolation circuit and an internal recording circuit, it can be easily applied to other transmission, storage, and storage systems.

[Effects of the Invention] As explained above, according to the present invention, the color signal obtained from the output signal of the imaging means is inserted into the no-signal period of the luminance signal obtained from the output signal of the imaging means, and the luminance signal and color signal are The number of transmission paths can be reduced by sequentially converting the signals into signals.

[Brief explanation of the drawing]

FIGS. 1 to 5 relate to the first embodiment of the present invention.
The figure is a block diagram explaining the configuration of the endoscope device, FIG. 2 is a timing chart explaining the operation, FIG. 3 is an illustration of the color filter array, FIG. 4 is an illustration of the display image on the monitor, 5 is an overall configuration diagram of the endoscope apparatus, FIG. 6 is a block diagram showing a modification of the first embodiment, and FIGS.
The figures relate to a second embodiment of the present invention; FIG. 7 is a block diagram of the endoscope apparatus, and FIG. 8 is a timing chart explaining the operation. 1... Endoscope 11 device 2... Endoscope 4... Camera control unit 20... Solid-state image sensor 36... Luminance color separation circuit 4
3... Sequentialization means 47... A/D converter 48.
...FIFO memory 49...D/Δ converter 51...
Adder 52...Isolation circuit 59...Post-process circuit Figure 8 Procedures (spontaneous) 1. Indication of the incident Relationship to the 1988 Patent Application No. 332259 incident

Claims (1)

[Scope of Claims] An image processing device comprising an imaging means for converting optical information into an electrical signal, and a video signal processing means for processing the electrical signal of the imaging means into a video signal, wherein the image processing means is a part of the imaging means. Image processing characterized by comprising a sequential means for sequentially generating a luminance signal and a color signal by inserting a color signal obtained from the output signal of the imaging means into a no-signal period of the luminance signal obtained from the output signal. Device.