JP4493387B2 - Electronic endoscope device - Google Patents

Description

  The present invention is an electronic endoscope apparatus, particularly an electronic endoscope capable of outputting a subject image to a high-definition television system monitor in an environment where various electronic endoscopes having different numbers of pixels of a solid-state imaging device are used. The present invention relates to a configuration of an endoscope apparatus.

  The electronic endoscope apparatus has a CCD (Charge Coupled Device) or the like, which is a solid-state image sensor, mounted on the tip of an electronic endoscope (electronic scope). The CCD is based on illumination of light from a light source device. The subject is imaged. The imaging signal obtained by the CCD of this electronic endoscope is output to the processor device, and the processor device performs image processing to display the image of the object to be observed on the monitor or record a still image or the like. It can be recorded on the device.

  In general, the above-mentioned object image is displayed on a monitor for NTSC system (aspect ratio 3: 4) which is a standard television system. For example, as disclosed in Japanese Patent Laid-Open No. 4-253830, the number of scanning lines Attempts have also been made to display a subject image on a high-definition television (HDTV) type monitor (aspect ratio 9:16) that is approximately twice as high. In the electronic endoscope apparatus, a normal NTSC system signal (analog signal) is formed from the output signal of the CCD. Therefore, the NTSC signal is converted into a high-definition television signal.

On the other hand, the still image (digital signal) of the object to be observed obtained by the electronic endoscope device is recorded on a recording medium by a filing device such as a personal computer (personal computer) and then displayed on a personal computer monitor for observation. At the same time, CCDs tend to use high resolution pixels with high resolution.
JP-A-4-253830

  As described above, in recent years, CCDs, which are solid-state imaging devices, have higher resolutions and higher pixel counts, so even in high-definition television image display, the image of the object to be observed has improved image quality compared to the past. However, if the NTSC signal is converted to a high-definition television signal as described above, it is limited to the resolution of the NTSC video signal, and the resolution of the high-quality CCD cannot be fully utilized. There's a problem.

The electronic endoscope is equipped with a CCD having a different number of pixels as described above, and a processor device for converting a high-definition television signal conversion circuit in response to the difference in the number of CCD pixels and the transition to a higher number of pixels. If they are arranged or updated (replaced), there is a problem that the cost is wasted and the apparatus becomes expensive.
Furthermore, strict standards for EMC (Electro-Magnetic Compatibility) and electrical safety are required for equipment used in the medical field. For conversion to high-definition television signals, a large dedicated device such as a personal computer is required. It is also impractical to ensure that the above medical standards are met.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an electronic endoscope using solid-state imaging devices having different numbers of pixels, using video output digitally processed for supply to a personal computer or the like. It is an object of the present invention to provide an electronic endoscope apparatus that can obtain a high-definition television system image with a simple configuration and low cost without reducing resolution.

In order to achieve the above object, the invention according to claim 1 is configured such that various electronic endoscopes having different numbers of pixels of a solid-state imaging device for imaging an object to be observed can be connected to a processor device. In an electronic endoscope apparatus that forms an analog video signal and a digital video signal from a signal obtained by an image sensor, the electronic endoscope apparatus is arranged in the processor device, and corresponds to the number of pixels of the solid-state image sensor and conforms to a display standard for an external computer. The digital video signal is formed, and the digital video signal is parallel-serial converted and output as a differential signal. The differential signal output unit is detachably connected to the differential signal output unit. detecting the number of pixels of said digital video signal based on a differential signal input from the signal output unit, converting to output the video signal of the number of pixels to HDTV signals That HDTV standards converter and the provided Rutotomoni, and the differential signal output section and the HDTV standards converter, using pulse transformers and Sadogata receiver for maintaining the differential-driver, a predetermined breakdown voltage It is characterized by being connected by a configured differential circuit .
According to a second aspect of the present invention, the HDTV converter is provided with an electronic enlargement circuit for electronically enlarging the image, and the image arbitrarily enlarged based on the differential signal input from the differential signal output unit A high-definition television signal is formed .

According to the above configuration, there are CCDs having various numbers of pixels (pixels), which are solid-state image pickup devices. Therefore, in a differential signal output unit (for example, DVI) for outputting to a personal computer or the like, 640 (horizontal direction) × 480 (vertical direction) pixel VGA (Video Graphics Array), 1024 × 768 pixel XGA (eXtended Graphics Array), 1280 × 960 pixel, 1280 × 1024 pixel SXGA (Super XGA), etc. A digital video signal conforming to the standard is formed, and this video signal is subjected to parallel-serial conversion and then output as a differential signal to a personal computer monitor or the like. When the digital video signal as the differential signal is supplied to the high-definition converter, the number of pixels of the video signal is detected, and a high-definition television signal corresponding to the number of pixels is formed. That is, a high-definition signal can be obtained using all the pixel information of the CCD. Therefore, just by connecting this high-definition converter to the processor device, it is possible to observe the object image (moving image or still image) on the high-definition monitor, and this image can be recorded on the high-definition recording device. it can.
In a differential circuit for transmitting a differential signal, the high-voltage converter side (power supply) is connected to the electronic endoscope (difference) by setting the breakdown voltage of the pulse transformer to, for example, 4 kV or more required by the electronic endoscope. It can be easily electrically separated from the dynamic signal output unit side.

According to the second aspect of the present invention, an image input from the differential signal output unit is enlarged by an electronic enlargement circuit at an arbitrary magnification and then converted into a high-definition television signal. A still image is displayed on a high-definition monitor with a size that allows easy observation .

According to the high-definition converter of the electronic endoscope apparatus of the present invention, the number of CCD pixels (resolution) employed is different using the output of the differential signal output unit for supplying digital video to a personal computer or the like. Even when an electronic endoscope is connected, it is possible to form a high-definition television system image with a simple configuration and low cost without reducing the resolution of the CCD and to output it to a high-definition monitor or recording device. . Further, the high-vision standards converter, by an adapter device filled with EMC and electrical safety standards required in the medical field, there is an advantage that high definition video viewing is facilitated in the medical field. Furthermore, by providing an electronic magnifying circuit, it is possible to display an object image having a size that is easy to observe on the high-vision monitor.

  1 to 3 show the configuration of an electronic endoscope apparatus according to the embodiment. First, the overall configuration will be described with reference to FIG. In FIG. 3, an electronic endoscope (electronic scope) 10 is provided with a CCD 11 which is a solid-state image pickup device at the tip thereof. As the CCD 11, 400,000 pixels, 800,000 pixels, 1.3 million pixels, etc. Various things are installed. In addition, a correlated double sampling (CDS) circuit 12 that samples the imaging signal output from the CCD 11 and a memory (EEPROM) 13 that stores identification information, video processing information, and the like of the electronic endoscope 10 are provided. Note that light from a light source device (not shown) is supplied to the electronic endoscope 10 via a light guide, and the object to be observed is picked up by the CCD 11 by outputting illumination light from the tip. . Various electronic endoscopes 10 having the above-described CCDs 11 having different numbers of pixels (or CCD transfer methods corresponding to the number of pixels) can be detachably connected to the processor device 16.

  The processor unit 16 selects an A / D converter 17, a first DSP (digital signal processor) 19, a second DSP 20, a third DSP 21, or the DSPs 19, 20 for performing various signal processing on video signals. Selector (S) 18, timing generator 22 for supplying synchronization signals and timing signals to the circuits from the CCD 11 to the first and second DSPs 19 and 20, a PLL circuit 23 having a crystal oscillator, and various controls. A synchronization signal generation circuit (SSG) 25 is provided for supplying a synchronization signal and timing signal to the microcomputer 24, the third DSP 21, and the like.

  Further, a fourth DSP 27 for forming a digital video signal and a DVI (Digital Visual Image) circuit 28 are provided at the subsequent stage of the third DSP 21, and this DVI circuit 28 is used for outputting to a monitor for a personal computer or the like. A video signal corresponding to a display standard such as VGA, XGA, SXGA or the like is formed, and then parallel-serial conversion is performed, and the serial signal is output as a differential signal to a personal computer monitor, a filing device, or the like. The DVI is a high-speed display interface set by the DDWG (Digital Display Working Group) and employs TMDS (Transition Minimized Differential Signaling) as a data format. On the other hand, the fourth DSP 27 is provided with a USB output unit 30 and a net output unit 31 via a signal conversion circuit 29. The USB output unit 30 and the net output unit 31 provide signals corresponding to respective output forms. Is output. Further, an analog signal processor 33 that converts a digitally processed video signal into an analog signal, a Y / C signal output unit 34 that outputs a luminance (Y) signal and a color difference (C) signal, and R An RGB output unit 35 for outputting (red), G (green), and B (blue) signals is provided.

  A high-definition converter 37 is provided so as to be detachably connected to the output section (terminal) of the DVI circuit 28, and the output of the high-definition converter 37 is connected to an HDTV monitor or an HDTV recorder. The Note that a part of what is described as a circuit in the processor device 16 in the configuration of FIG. 3 can be arranged on the electronic endoscope 10 side.

FIG. 1 shows a detailed configuration of the DVI circuit 28 and the high-definition converter 37. In the DVI circuit 28, the signal processing unit 39 for forming the above-mentioned video of each display standard, RGB signals, Transmitters (including an encoder / serializer) 40A, 40B, and 40C for transmitting a synchronization signal, a control signal, and the like are provided. The DVI circuit 28 is connected to a high-definition converter 37 via a serial transmission cable 41. The high-definition converter 37 includes receiving units 42A, 42B corresponding to the three transmitting units 40A, 40B, 40C. , 42C, ICA (Inter Channel Alignment) unit 43, HDTV (high-definition television) signal conversion unit (FPGA-Filed Programmable Gate Array circuit) 44 that detects the number of pixels of video and forms a high-definition television signal, and executes various controls And a frame memory 46 for temporarily storing the input video signal. The HDTV signal conversion unit 44 is connected to an electronic enlargement circuit 47 and is connected to the connector 49 to perform D / A conversion corresponding to a luminance (Y) signal and Pr and Pb signals as color difference signals. Devices 48A, 48B, 48C are provided.

  FIG. 2 shows the configuration of the HDTV signal conversion unit 44. The HDTV signal conversion unit 44 receives a horizontal synchronization signal (H), a vertical synchronization signal (V), a video signal, and a clock signal. A pixel number detecting circuit 44a for detecting the number of pixels of the video signal, a synchronizing signal generating circuit 44b for forming a high-definition video, a memory controller 44c for controlling writing and reading of the video signal to and from the frame memory 46, and the memory controller A signal converter 44d is provided for converting the RGB signals output from 44c into Y, Pr, and Pb signals that are high-definition images.

  The embodiment has the above-described configuration, and the operation thereof will be described with reference to FIGS. First, in this electronic endoscope apparatus, the object to be observed is imaged by the CCD 11 in FIG. 3, the imaged signal is sampled by the CDS circuit 12, and converted into a digital signal by the A / D converter 17. It is supplied to the selector 18. The selector 18 selects either the first DSP 19 or the second DSP 20 according to the type of the connected electronic endoscope 10. For example, the microcomputer 24 reads information in the memory 13 through communication between the electronic endoscope 10 and the processor device 16, so that the first DSP 19 corresponds to the number of pixels of the CCD 11 (or the CCD transfer method corresponding to the number of pixels). (In the case of interline scanning) or the second DSP 20 (in the case of progressive scanning) is selected.

  The first DSP 19 or the second DSP 20 and the third DSP 21 perform various kinds of video processing, and the output of the third DSP 21 is supplied to the fourth DSP 27 and the analog signal processor 33. In the fourth DSP 27, a video signal for digital output is formed. This video signal is output to the outside via the signal conversion circuit 29, the USB output unit 30, and the network output unit 31, and the DVI circuit 28. Can be output to a personal computer monitor or the like. On the other hand, in the analog signal processor 33, a video signal for analog output is formed, and Y and C signals are output via the Y / C signal output unit 34, and R and R are output via the RGB output unit 35. Each color signal of G and B is output.

On the other hand, when the output of the DVI circuit 28 is supplied to the HDTV converter 37, the HDTV converter 37 forms a HDTV signal. That is, for example, 640 × 480 (VGA), 1024 × 768 (XGA), 1280 × 960, 1280 × 1024 (SXGA) corresponding to the number of pixels of the CCD 11 by the signal processing unit 39 of the DVI circuit 28 shown in FIG. A video signal of the display standard is formed. The parallel signals [B (blue), G (green), R (red), H (horizontal synchronization signal), V (vertical synchronization signal), C ₀ , C ₁ , C] output from the signal processing unit 39 are output. ₂ , C ₃ (control signal), etc.] are converted into serial signals by the transmitters 40 </ b> A to 40 </ b> C and output to the high-definition converter 37 via the cable 41. As shown in FIG. 1, the B signal and H, V signals transmitted from the transmitter 40A are received by the receiver 42A, the G signal transmitted from the transmitter 40B and other signals are received by the receiver 42B, and the transmitter 40C. The R signal and other signals transmitted from are received by the receiving unit 42C. In these receiving units 42 </ b> A to 42 </ b> C, the serial signal is converted into the original parallel signal, and this signal is supplied to the HDTV signal converting unit (FPGA) 44 via the ICA circuit 43.

  In the HDTV signal conversion unit 44, the input video signal is stored in the frame memory 46 via the memory controller 44c of FIG. 2, and at the same time, the number of pixels of the input video signal is, for example, horizontally synchronized by the pixel number detection circuit 44a. It is detected by a signal or a vertical synchronization signal. That is, as shown in FIG. 4A, the horizontal synchronization signal (H) of the HDTV system has a length of 1920 pixels and the vertical synchronization signal (V) has a length of 1080 pixels, but is input to the converter 37, for example. When 1024 horizontal pixels are detected (counted) by the horizontal synchronization signal of the video signal, or when 768 vertical pixels are detected by the vertical synchronization signal, the video (image) is 1024 × 768 XGA standard. It is judged. Similarly, when a 1280 horizontal pixel or 960 vertical pixel is detected, a 1280 × 960 image, and when a 640 horizontal pixel or 480 vertical pixel is detected, a 640 × 480 VGA standard image is displayed. When a horizontal pixel or 1024 vertical pixels are detected, it is determined that the image is a 1280 × 1024 SXGA image. Then, the detection result of the number of pixels is supplied to the synchronization signal generating circuit 44b and the memory controller 44c, whereby the memory controller 44c performs the video signal reading control from the frame memory 46 according to the number of pixels.

For example, as shown in FIG. 4B, black is assigned to all horizontal pixels from 1 to 156 in the vertical direction, and for the 157th vertical direction, the XGA video signal is transmitted from 449 to 1472 in the horizontal direction. In such a manner, video signals (RGB signals) in a range surrounded by the pixels of (449, 157), (1472, 157), (449, 924), and (1472, 924) are read out. Black is assigned to the other pixels. In the signal converter 44d, the RGB signals are converted into Y, Pr, and Pb signals, and the Y, Pr, and Pb signals and the synchronization signal are output to the HDTV monitor and the HDTV recorder. In this way, as shown in FIG. 4C, the HDTV monitor has a high-definition image in which a 1024 × 768 pixel object image is arranged in the central area, that is, a 1920 × 1080i (interlace) pixel. A video (format D ₄ ) is displayed.

FIG. 5A shows a high-definition video when a video of 1280 × 960 pixels is detected. In this case, an 1280 × 960 pixel object image is arranged in the central region on the HDTV monitor. The high-definition video is displayed. FIGS. 5B and 5C show high-definition images when a 640 × 480 pixel VGA image is detected. In this case, as shown in FIG. , the format D _4, may display the high-definition image arranged around the observation object image 640 × 480 pixels, but because a little smaller, in the embodiment, the format from the format D ₄ at the memory controller 44c performs conversion to D _3, 5 as shown in (C), and to display the high-definition video formats _{D 3} pixels of 1280 × 720i arranged around the observation object image 640 × 480 pixels.

  Further, in the embodiment, an electronic enlargement circuit 47 is provided as shown in FIG. 1, and the electronic enlargement circuit 47 can display an enlarged image in a size (image size) that can be easily observed. For example, a switch or the like for arbitrarily setting the electronic enlargement ratio is provided in the high-definition converter 37 itself (or the electronic enlargement ratio may be set from a processor device or an external device), and the electronic enlargement is made via the microcomputer 45. The enlargement ratio of the circuit 47 is controlled. That is, the electronic enlargement circuit 47 is supplied with video signals of various numbers of pixels supplied to the HDTV signal conversion unit 44, and a signal that is enlarged from the video signal to a set magnification is formed. The signal is returned to the HDTV signal converter 44. The memory controller 44c of the HDTV signal conversion unit 44 writes this enlarged video signal into the frame memory 46 and then reads out the signal corresponding to the high-definition method as described above, thereby forming a high-definition television signal. . As a result, the high-definition monitor displays the object image magnified at the set magnification, and the observation of the object can be further facilitated.

6 and 7 show the configuration of a differential circuit for connecting the DVI circuit 28 and the HDTV converter 37. FIG. FIG. 6 shows an embodiment using a pulse transformer. In this example, as shown in the figure, as a differential driver in the DVI circuit 28, logic circuits 52a to 52c and transistors 53a to 53d, for example, maintain a withstand voltage of 4 kV or higher. A pulse transformer 54 and the like are provided, and comparators 55a and 55b, transistors 56a and 56b, and the like are provided as differential receivers in the HDTV converter 37. FIG. 7 shows a reference example using a capacitor. In this example, a differential output circuit 57 and the like are provided in the DVI circuit 28 as shown in the figure, and a withstand voltage of, for example, 4 kV or more is provided in the high-definition converter 37. Capacitors 58a and 58b, a differential input circuit 59, and the like are provided.

According to the differential circuit of this embodiment, since the withstand voltage of the pulse transformer 54 is set to 4 kV or more required by the endoscope apparatus, the differential signal input / output can be performed without providing an isolation circuit. Therefore, the DVI 28 and the high-definition converter 37 can be electrically separated from a commercial power source or the like using a circuit, and the safety of the electronic endoscope 10 can be easily ensured.

It is a circuit block diagram which shows the structure of the DVI circuit and high vision system converter of the electronic endoscope apparatus which concerns on the Example of this invention. It is a figure which shows the structure of the HDTV signal converter in the hi-vision system converter of FIG. It is a circuit block diagram which shows the whole structure of the electronic endoscope apparatus of an Example. It is explanatory drawing which shows the pixel number detection [FIG. (A)] performed by the high vision system converter of an Example [FIG. (A)], the conversion to a high-definition television signal, and a display state [FIG. (B), (C)]. . Display state of the 1280 × 960 video signal formed by the high-definition converter of the embodiment on the high-vision monitor [FIG. (A)] and display state of the VGA standard video signal on the high-vision monitor [FIG. (B), It is explanatory drawing which shows (C)]. It is a circuit diagram which shows the structure at the time of using a pulse transformer as a differential circuit which connects the DVI circuit of an Example, and a high vision system converter. It is a circuit diagram showing a configuration of a reference example using a capacitor as the difference Dogata circuit.

Explanation of symbols

10 ... Electronic endoscope, 16 ... Processor device,
24, 45 ... microcomputer, 27 ... 4th DSP,
28 ... DVI circuit (differential signal output unit),
37 ... Hi-Vision converter
44 ... HDTV (high-definition television) signal converter,
44a ... Pixel number detection circuit,
44c ... Memory controller,
46 ... Frame memory, 47 ... Electronic enlargement circuit,
54 ... pulse transformer,
58a, 58b ... capacitors.

Claims (2)

Various electronic endoscopes with different numbers of pixels of the solid-state imaging device for imaging the object to be observed are configured to be connectable to the processor device, and analog video signals and digital video signals are obtained from the signals obtained by the solid-state imaging device. In the electronic endoscope device to be formed,
A digital video signal arranged in the processor unit, corresponding to the number of pixels of the solid-state imaging device and conforming to a display standard for an external computer is formed, and the digital video signal is parallel-serial converted and output as a differential signal. Differential signal output unit,
The relative differential signal output unit is detachably connected, on the basis of a differential signal input from the differential signal output section detects the number of pixels of the digital video signal, HDTV signal a video signal of this number of pixels and HDTV standards converter for converting output, the provided to Rutotomoni,
The differential signal output unit and the HDTV converter are connected by a differential circuit configured using a differential driver, a pulse transformer for maintaining a predetermined withstand voltage, and a differential receiver. An electronic endoscope apparatus. The high-definition converter is provided with an electronic enlargement circuit that electronically enlarges an image, and forms a high-definition television signal of an arbitrarily enlarged image based on the differential signal input from the differential signal output unit. electronic endoscope apparatus 請 Motomeko 1 wherein said.

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