JP4249841B2 - Electronic endoscope apparatus having a zooming function - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic endoscope apparatus, and more particularly, to a configuration of an apparatus that images an object to be observed with a solid-state imaging device using a zooming function capable of enlarging an observation image with an objective optical system.
[0002]
[Prior art]
Recently, a zooming drive mechanism for changing the observation distance or making the focal length variable is incorporated in the insertion tip of the endoscope, and a movable lens that is a component of the zooming mechanism is driven. Proposed. For example, the rotational driving force of a motor is transmitted to a magnification changing mechanism using a linear transmission member, for example, a multi-coil spring member, where the rotational motion is converted into a linear motion and a predetermined movable lens of the objective optical system. Is moved back and forth to execute a scaling operation. According to this, the observed object image can be enlarged and observed, and a fine diagnosis can be performed.
[0003]
[Problems to be solved by the invention]
By the way, the conventional electronic endoscope apparatus is provided with an electronic zoom function for enlarging (or reducing) an image signal (video signal) obtained by a CCD (Charge Coupled Device) which is a solid-state imaging device. Therefore, if this electronic scaling function and the above-described optical scaling function can be combined, the enlargement ratio can be improved.
In this case, the optical scaling function and the electronic scaling function are not simply provided, but switching and transition of these functions during the scaling operation are required to be performed smoothly without a sense of incongruity.
[0004]
The present invention has been made in view of the above problems, and its purpose is to improve the enlargement ratio by combining the optical magnification function and the electronic magnification function, and to shift between both functions during magnification operation. An object of the present invention is to provide an electronic endoscope apparatus having a zooming function that can be performed smoothly.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an electronic endoscope apparatus having a zooming function according to claim 1 includes an optical zooming mechanism capable of optically enlarging an observation image by an objective optical system, and the objective optical system. a solid-state imaging device for imaging the object to be observed by the incident light, the image signal obtained by the solid-state imaging device and signal processing, electronic magnification operation start to further expand the direction of the image from the enlarged end of the optical zooming Or an electronic magnification circuit that starts an electronic magnification operation from the wide-angle end of the optical magnification and forms an image in a further reduction direction, and a constant displacement speed of the magnification is set. At the time of zooming of the optical zoom mechanism, the displacement speed is detected from the zoom position information between predetermined sampling counts, the detected speed is stored in the storage unit, and the shift to the electronic zooming is performed. By loading the above detection speed to Characterized in that it comprises a and a variable speed of the control circuit for controlling such magnification displacement speed matches the behavior and transition points of the electronic magnification of the operation of the optical zooming.
The invention according to claim 2 is characterized in that the optical scaling operation, the electronic scaling operation, and the transition control between the two operations are executed by the same scaling switch .
[0006]
According to the above configuration, by driving, for example, the movable lens of the optical zoom mechanism, the observation distance is changed from the wide angle (far) end to the enlargement (near) end, and after the movable lens reaches the enlargement end, The electronic scaling function works, and a further enlarged image can be obtained. In this case, the driving speed by the movable lens, that is, the magnification displacement speed is detected. When shifting to the electronic magnification operation (also when returning to the optical magnification operation), the displacement speed is referred to. The electronic zooming operation is executed at the same displacement speed. Accordingly, even at the time of transition between both functions, the image scaling display is performed without a sense of incongruity.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show the configuration of an electronic endoscope apparatus having a zooming function according to the embodiment, and the electronic endoscope (scope) 10 of FIG. Connected. The electronic endoscope 10 includes a front lens 13 and a movable lens 14 that moves back and forth as a varifocal objective optical system for changing the observation distance and a zoom objective optical system that variably corresponds to the focal length. A CCD 16 is disposed behind the movable lens 14 via, for example, a prism 15 shown in FIG.
[0008]
FIG. 2 shows the configuration of the optical zoom drive mechanism. As shown in the drawing, the objective optical system including the movable lens 14 is disposed at the distal end portion 10 </ b> A of the electronic endoscope 10. The holding member 18 of the movable lens 14 has a female screw portion 18A in the upper portion thereof, and a rotary drive body 19 for screwing the male screw portion 19A to the female screw portion 18A is disposed. A linear transmission member (multiple coil spring member) 20 made of a multiple coil spring member or the like is connected.
[0009]
The linear transmission member 20 is disposed up to the variable power motor portion 21 of the operation unit 10B located at the base of the flexible insertion portion of the electronic endoscope 10, and gears 22A and 22B are connected to the linear transmission member 20. Via the motor 24. Therefore, when the motor 24 is rotated, the movable lens 14 is moved back and forth by the screwed connection of the rotational drive body 19 at the tip of the linear transmission member 20 and the screw portions 18A and 19A of the holding member 18, thereby changing the magnification. Done. In this example, the observation distance (focal length) is set in the far distance (Far) direction by extending the movable lens 14 to the front side, and is set in the near distance (Near) direction by moving it backward.
[0010]
On the other hand, an encoder 25 is attached to the holding member 18 of the movable lens 14, and the encoder 25 detects the magnification position (drive position) of the movable lens 14. As shown in FIG. 1, the output of the encoder 25 is supplied to the variable magnification motor unit 21, and position control is performed based on the current detection position and the target variable magnification position. Note that the encoder 25 or a similar detection member may be disposed on a rotating portion or the like on the operation portion 10B side, as indicated by 25 'in FIG.
[0011]
In FIG. 1, for example, an operation unit (10B) of the electronic endoscope 10 is provided with a zoom switch 27 and a zoom speed (setting) switch 28 including a toggle switch and a seesaw switch. The movable lens 14 can be moved in the enlargement direction by connection to the terminal a and in the reduction direction by connection to the terminal b. Further, the zooming speed switch 28 can set a zooming speed. In this example, for example, high speed (for example, about 3 times / sec), medium speed (for example, about 2 times / sec), The speed is selected from three speeds of low speed (for example, about 1.5 times / sec). In addition to this, a freeze button or the like for forming and recording a still image is arranged on the operation unit (10B).
[0012]
Further, a light guide 30 is disposed from the electronic endoscope 10 to the light source and the light source unit of the processor device 12, and a diaphragm 32 is provided at a light incident end of the light guide 30 via a condenser lens 31. A light source lamp 33 is disposed behind the diaphragm 32. The aperture 32 is driven by an aperture drive circuit 34, and the brightness of the image can be maintained constant by adjusting the amount of output light by controlling the aperture of the aperture 32.
[0013]
The light source and processor device 12 is provided with an A / D converter 36 for digitally converting the analog output of the encoder 25, which is connected via an I / O unit 37 to a CPU 38 for overall control of each circuit. The CPU 38 is connected to a ROM 39 for storing data such as an electronic shutter speed control pattern (table). The diaphragm drive circuit 34, the zoom speed switch 28, and the like are also connected to the CPU 38 via the I / O unit 37. The CPU 38 calculates the displacement speed of the optical magnification, which will be described in detail later, based on the magnification position detected by the encoder 25.
[0014]
In addition, a CCD drive circuit 41 including a timing generator (TG) is provided connected to the CCD 16. The CCD drive circuit 41 controls the drive of the CCD 16, and receives a command signal from the CPU 38 during the magnification change operation. In response, electronic shutter control is executed. In other words, the charge accumulation time (exposure time) is changed by adjusting the sweep time in the charge accumulation operation of the CCD 16 based on the control pattern of the electronic shutter stored in the ROM 39, compared with when the magnification changing mechanism is not used. a high Te Ri, for example it is possible to set the shutter speed up to 1/10000 seconds. By this electronic shutter speed control, it is possible to suppress image blurring that becomes noticeable when the image is enlarged.
[0015]
On the other hand, a CDS (Correlated Double Sampling) / AGC (Automatic Gain Control) circuit 43 that performs clamp processing, signal amplification processing, and the like to perform image processing on the video signal obtained by the CCD 16. A / D converter 44, for example, a signal processing circuit 45 that forms color difference signal C and luminance signal Y and performs various processes such as gamma correction and contour correction, and a RAM that stores processing data of the signal processing circuit 45 (Random Access Memory) 46, a D / A converter 47, an encoder 48 for performing output processing to a monitor, and the like are provided. Here, the luminance signal Y obtained by the signal processing circuit 45 is also supplied to the CPU 38, and the CPU 38 controls the opening amount of the light source diaphragm 32 so that the luminance signal Y becomes a predetermined value. As a result, the brightness of the image (screen) is maintained constant.
[0016]
In addition, an electronic scaling IC circuit 50 is provided in connection with the RAM 46, and the scaling IC circuit 50 performs image processing for electronic scaling under the control of the CPU 38. In this example, as shown in FIG. 3, electronic zooming is performed in the direction of further magnification from the zooming end of the optical zooming, and an image at the zooming end of the optical zooming is stored in the RAM 46, and this image is stored in the original image. Are read and enlarged. The use or non-use of the electronic scaling function can be selected by a switch on a control panel (not shown). Further, the CPU 38 detects the displacement speed at the time of optical zooming, and controls so that the displacement speed between the optical zooming and the electronic zooming becomes the same.
[0017]
In other words, the zoom speed switch 28 sets the displacement speed in three stages of high speed, medium speed, and low speed, but the optical zoom mechanism uses a relatively long linear transmission member, and the endoscope is free. Therefore, the actual driving speed is not always as set, changes depending on various conditions, and slightly differs in the enlargement direction and the reduction direction. In this example, as shown in FIG. 3, for example, as shown by z1 in the enlarged CW direction and z2 in the wide-angle CCW direction, the CPU 38 calculates the magnification speed from the magnification position information moving between the sample counts 5. The electronic scaling IC circuit 50 executes the electronic scaling operation at the same scaling speed as this speed. The signal processing circuit 45 performs not only the display processing of the object image to be observed but also image processing for indicating whether the zooming speed and the current zooming operation are optical zooming or electronic zooming. For example, as shown in FIG. 4, “high speed, medium speed, low speed” indicating zooming speed, “O” indicating optical zooming, and “E” indicating electronic zooming are displayed at the four corners 41C of the screen. Is displayed.
[0018]
According to the configuration of the above-described embodiment, light from the light source lamp 33 in FIG. 1 is irradiated from the distal end portion of the electronic endoscope 10 through the light guide 30, whereby the object to be observed is in the objective optical systems 13 and 14. Is captured by the CCD 16. When the zoom switch 27 of the operation unit of the electronic endoscope 10 is not operated and the movable lens 14 is in the standard position, the electronic shutter control is not executed, and the CCD drive circuit 41 outputs, for example, a fixed sweep pulse. The accumulated charge is read out for about 1/60 second after being applied. Then, the read signal is processed as a video signal, whereby the color difference signal C and the luminance signal Y are output from the encoder 48, whereby an image in the observation object is displayed on the monitor.
[0019]
On the other hand, when the magnification switch 27 is operated, the rotation lens 19 shown in FIG. 2 is rotated via the linear transmission member 20 by driving the magnification motor unit 21 to move the movable lens 14 from the standard position to the front side. Since it is moved, the image is enlarged. At the same time, the encoder 25 detects the optical scaling position (enlarged position) of the movable lens 14, and this position detection value is used as a control value in the scaling motor unit 21 and also the current scaling ratio. Position information is supplied to the CPU 38 via the I / O unit 37. Then, the CPU 38 calculates a magnification speed (magnification displacement speed) from the optical magnification position data and sets this speed as a magnification speed when shifting to electronic magnification.
[0020]
Next, the operation of the embodiment mainly using the above-described zoom speed setting control will be described. FIG. 5 shows a motor speed setting flow. When the power is turned on, in step (hereinafter referred to as Step) 101, for example, high speed, medium speed, and low speed set by the zoom speed switch 28 are set. A motor drive speed control voltage is set, and a reference current b for preventing motor overload, for example, high speed = b1, medium speed = b2, and low speed = b3 are set in Step 102. In Step 103, the speed is displayed on the four corners 41C of the monitor 41 as described in FIG.
[0021]
FIGS. 6 and 7 show a motor control flow for optical zooming. When the zooming switch 27 is pressed, in step (hereinafter referred to as “Step”) 201, the pressing direction is the CW (clockwise) direction. Or CCW (counterclockwise) direction. Here, in this example, the CW direction is set to the enlargement direction, and the CCW direction is set to the wide angle (reduction) direction. If it is the CW direction, it is determined whether or not an enlargement (Near) end is detected in Step 202. , “N (NO)”, the count n of the CCW direction control on the opposite side is set to 0 in Step 203, and the motor 24 is rotated in the CW direction in Step 204. Next, the load current a of the motor 24 is detected (Step 205), and the reference current b (b1, b2, b3) is detected (Step 206).
[0022]
In Step 207 of FIG. 7, it is detected whether or not the load current a> the reference current b (b1, b2, b3). If “Y (YES)”, the motor 24 is stopped to cancel the overload state. To do. In the next Step 209, the output detection value of the encoder 25 is sampled, the count m is incremented by 1 (m + 1) (Step 210), and in Step 211, it is determined whether or not the sample count m is k (for example, k = 5). If the count m = k, the zooming speed in the enlargement direction is calculated in Step 212. That is, as shown in FIG. 3, for example, the magnification speed δ is obtained by sampling (z1) at five magnification positions in the CW direction. In Step 213, the existing speed (previous calculation speed) δ in the enlargement direction is cleared (erased), and the magnification speed δ obtained in Step 212 is stored in the RAM 46 (Step 214). Thereafter, the count m is set to 0 in Step 215, and the process returns to Step 201.
[0023]
On the other hand, if the pressing direction of the zoom switch 27 is the CCW direction in Step 201 of FIG. 6, the process proceeds to Step 217 to determine whether or not the wide angle (Far) end has been detected. 24 is stopped (Step 218). If “N”, the counter CW direction control count m = 0 is set at Step 219, and the motor 24 is rotated in the CCW direction at Step 220. Subsequent Step 221 to Step 231 (FIG. 7) are the same as the operations from Step 205 to Step 215 in the CW direction, and here, for example, five zoom positions of sampling Z2 in FIG. 3 when moving in the wide angle (reduction) direction. Based on the data, the zoom displacement speed γ in the wide angle direction is calculated, and the speed data γ in the RAM 46 is sequentially updated.
[0024]
Next, when the enlarged end is detected (Y) in the detection of the enlarged end in Step 202, the process proceeds to Step 233, and it is determined whether or not the electronic scaling control is selected / set. In other words, in this example, use / nonuse of the electronic magnification mode can be selected. If the electronic magnification mode is set to nonuse (N), the motor 24 is stopped (Step 234). ), When it is set to use (Y), the process shifts to electronic scaling control (Step 235).
[0025]
8 to 10 show the electronic scaling control flow. As described with reference to FIG. 7, the enlargement end is detected in Step 202, and the electronic scaling control is selected (turned on) in Step 233. Shifts to the electronic magnification enlargement direction flow H1. That is, as shown in FIG. 9, in Step 301, 1 is added to the count ne (ne +1), and in the next Step 302, it is determined whether or not the count ne is 1.
[0026]
Immediately after the transition to the electronic magnification mode, this step 302 becomes “Y”, the CW direction displacement speed δ stored in step 214 is loaded from the RAM 46 in step 303, and the CCW direction displacement speed γ stored in step 230 in step 304. After that, the original image data is written to the RAM 46 (Step 305). That is, an image when the enlargement end is reached by the optical zoom is written as an original image.
In the next Step 306, since the same magnification command data as the original image is output to the mode register in the electronic scaling IC circuit 50, the scaling IC circuit 50 outputs the same size image data (Step 307).
[0027]
If ne is not 1 in Step 302 (N), the enlargement ratio command data is output to the mode register in the electronic scaling IC circuit 50 (Step 308), and the process proceeds to the next Step 309. In Step 309, it is detected whether or not the electronic enlargement ratio Z is at the upper limit value (Z = × L). When the electronic enlargement ratio Z has not reached the upper limit value, the image data of the command enlargement ratio is converted into an electronic scaling IC circuit. 50 (Step 310) and return to the original Step 201. Here, when the zoom switch 27 is continuously pressed in the CW direction, images with a larger enlargement ratio are sequentially output through Step 310, and the output / display of the enlarged image is performed at the speed δ read in Step 303. Will change. For example, when the medium speed is selected, an image is displayed at the medium speed or an actual zooming displacement speed in the vicinity thereof (for example, a speed around 2 seconds / sec).
[0028]
If the enlargement factor Z is at the upper limit in Step 309 above, ne = ne −1 is calculated (Step 311), and after confirming that ne = 0 is not zero (N) in the next Step 312, the enlargement factor upper limit is obtained in Step 313. Command data is output, and an image with the maximum magnification is repeatedly output from the electronic scaling IC circuit 50. On the other hand, when ne = 0 (Y) in Step 312 above, the electronic magnification changing IC circuit 50 is in a state where the pressing operation of the magnification changing switch 27 in the CW direction is released immediately after the electronic magnification changing control is entered. Is turned off (Step 315), ne = 0 is again performed (Step 316), and the process proceeds to the motor control flow.
[0029]
When the magnification switch 27 is pushed in the CCW direction during the execution of the above-described electronic magnification control, the flow shifts from Step 201 in FIG. 8 to the electronic magnification / wide angle direction flow H2 in the CCW direction. That is, as shown in FIG. 10, it is determined in Step 320 whether or not the enlargement end of the optical scaling has been detected. When “N”, since optical scaling is possible, ne = After 0 is executed (Step 321), the image output of the electronic scaling IC circuit 50 is turned off in Step 322, and the process proceeds to the motor control flow.
[0030]
On the other hand, if the enlargement end is detected in Step 320, it is determined in Step 324 whether the setting of electronic scaling is on or off. If it is on (Y), ne = ne − 1 is calculated (Step 325), and the reduction ratio command data is output to the mode register of the electronic scaling IC circuit 50 in Step 326. Thereafter, in Step 327, it is determined whether or not the electron magnification ratio Z is a lower limit value (Z = × 1, which is the same as the maximum value of the optical magnification). The image of the command reduction rate is output by the IC circuit 50 (Step 328). Here, when the zoom switch 27 is continuously pressed in the CCW direction, images that are reduced (the enlargement rate is reduced) are sequentially output via Step 328, and output / display of the reduced image is performed. It changes at the zoom speed γ read in Step 304 above.
[0031]
On the other hand, when “Y” in Step 327, that is, when the lower limit value of the electronic magnification is reached, ne = 0 is calculated in Step 329 and the process proceeds to the motor control flow. Also, when the electronic scaling setting is OFF (N) in Step 324, ne = 0 is calculated in Step 330 and the process proceeds to the motor control flow.
[0032]
As described above, electronic zooming functions in the direction of further zooming from the zooming end of the optical zooming by operating the zooming switch 20, and the zooming displacement during the transition between these zooming functions is smooth at the same speed. Thus, optical scaling and electronic scaling are executed without a sense of incongruity. Further, as described with reference to FIG. 4, “O” is displayed on the monitor 41 during the optical zooming operation and “E” is displayed during the electronic zooming operation. Can be confirmed.
During the optical scaling operation, a video signal is read from the CCD 16 using a high-speed electronic shutter, thereby forming a blur-free image.
[0033]
In the above embodiment, the electronic scaling function is used in the direction of enlarging from the enlargement end of optical scaling, but it is also possible to provide the electronic scaling function in the same direction in the direction of further reduction from the wide angle end of optical scaling. is there.
[0034]
【The invention's effect】
As described above, according to the present invention, an optical zoom mechanism that magnifies an observation image using an objective optical system, and an electron that forms a magnified image or a reduced image with respect to an image at the magnification end or wide angle end of the optical magnification variation. A magnification circuit is provided to control the displacement speed of the magnification to be a set constant speed, and the displacement speed is detected from the magnification position information during a predetermined sampling count at the time of magnification of the optical magnification mechanism. The detection speed is stored in the storage unit, and the detection speed is loaded at the time of transition to electronic zooming so that the displacement speed at the transition point between the optical zooming operation and the electronic zooming operation is matched. As a result, the enlargement ratio can be improved by combining the optical scaling function and the electronic scaling function, and at the same time, the transition between both functions can be smoothly performed during the scaling operation. In particular, even when a magnification changing mechanism that transmits a motor driving force using a linear transmission member is used, it is possible to accurately match the magnification changing speeds.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of an electronic endoscope apparatus having a scaling function according to an embodiment of the present invention.
2 is a partial cross-sectional view showing a configuration of an optical zoom mechanism in the electronic endoscope of FIG. 1. FIG.
FIG. 3 is an explanatory diagram showing a relationship between optical scaling and electronic scaling and how to take sample data in the embodiment.
FIG. 4 is a diagram illustrating a display of an operation state related to zooming on a monitor in the embodiment.
FIG. 5 is a flowchart showing a speed setting operation of the optical zoom motor according to the embodiment.
FIG. 6 is a flowchart showing an optical variable motor control operation of the embodiment.
FIG. 7 is a flowchart continued from FIG. 6, showing an optical variable motor control operation of the embodiment.
FIG. 8 is a flowchart illustrating an electronic scaling control operation according to the embodiment.
FIG. 9 is a flowchart showing the electronic magnification enlargement direction operation of FIG. 8 in the electronic magnification control operation of the embodiment.
10 is a flowchart showing the operation of the electronic variable magnification wide angle (reduction) direction of FIG. 8 in the electronic variable magnification control operation of the embodiment.
[Explanation of symbols]
10 ... Electronic endoscope,
12: Light source / processor device,
14 ... movable lens, 16 ... CCD,
20 ... linear transmission member, 21 ... variable power motor,
25 ... Encoder, 27 ... Variable power switch,
28 ... Variable speed switch, 38 ... CPU,
41 ... CCD drive circuit, 45 ... signal processing circuit,
46: RAM, 50: Electronic magnification IC circuit.

Claims (2)

An optical zoom mechanism capable of optically enlarging an observation image by an objective optical system;
A solid-state imaging device that images an object to be observed with incident light from the objective optical system;
Signal processing is performed on the image signal obtained by the solid-state imaging device, and an electronic magnification operation is started from the enlargement end of the optical magnification to form an image in the enlargement direction, or electrons are produced from the wide angle end of the optical magnification. An electronic scaling circuit that starts a scaling operation and forms an image in a further reduction direction ;
Control is performed so that the displacement speed of zooming becomes a set constant speed, and at the time of zooming of the optical zooming mechanism, the displacement speed is detected from zooming position information between predetermined sampling counts, and this detection speed is determined. By storing in the storage unit and loading the detection speed at the time of shifting to the electronic scaling, the zooming displacement speed at the transition point between the optical scaling and the electronic scaling is matched. An electronic endoscope apparatus having a zooming function including a zooming speed control circuit for controlling the zooming speed. The optical zooming operation, the electronic endoscope having a magnification change of the electronic zoom operation and 請 Motomeko 1 wherein the transition control between both operations you characterized in that so as to run on the same zooming switch Mirror device.