JP3362955B2 - Imager with built-in light source - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device with a built-in light source having a function of processing an image pickup signal and adjusting the amount of illumination of a light source. 2. Description of the Related Art A prior example of improving the electrical sensitivity of an integral type imaging means by controlling the exposure time of a CCD as an imaging means is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-191582. I have. The purpose of this TV camera device is to improve the sensitivity under low object illumination even without an AGC circuit. FIGS. 9 and 10 show a T having an integrating function.
The figure shows an integrated device combining a V-camera device (hereinafter referred to as CCU) and a light source device. In this device 81, an aperture control knob 82 of the light source unit and a knob 8 of variable integration time are provided.
3 are provided independently. FIG. 10 is an overall configuration diagram of the endoscope apparatus including the integrated apparatus of the endoscope light source and the CCU shown in FIG. [0004] An endoscope apparatus 80 shown in FIG.
4 and the integrated device 81 connected to the endoscope 84
And The distal end of the insertion portion of the endoscope 84 has C
An emission end of a light guide 87 for transmitting illumination light from a CD 85 and a light source lamp 86 of the integrated device 81 is arranged. The output signal of the CCD 85 passes through a process circuit 88 of the integrated device 81 and is output as a standard TV signal by an encoder 89. The exposure time control circuit 91 adjusted by the integrating knob 83
By controlling the drive signal of the CD 85, the exposure time of the CCD 85 is controlled. A stop 92 disposed between the light source lamp 86 and the incident end of the light guide 87 is controlled by a stop control circuit 93. The aperture control circuit 93 is adjusted by the aperture control knob 82. In this apparatus, the brightness of a TV signal as an output changes when the aperture control knob 82 or the integral knob 83 shown in FIG. 9 is turned. As is apparent from FIG. 10, the two knobs are provided independently of each other without any functional relation. The light amount adjusting means of the light source device includes:
It is adjusted by a diaphragm as disclosed in JP-A-63-276018. However, the light amount adjustment by the aperture is generally inefficient because the lamp of the light source is always used with full light emission. In particular, when the battery is used, since the lamp always emits full light, there is a drawback in that the use time when using the battery is shortened. In addition, the battery had to be enlarged in order to increase the use time. Therefore, as a means for adjusting the light amount with high efficiency, a dimming method for directly controlling the lamp current and controlling the light amount of the lamp has been widely put to practical use in the field of headlights of automobiles and the like. However, in the dimming method that controls the lamp current, the brightness changes according to the lamp current, and the color temperature of the lamp emission color also changes. In an automobile or the like, a change in color temperature does not cause much problem. However, in a light source device of an endoscope, since fidelity is required for color reproducibility, it becomes a serious problem. As a means for correcting a change in color temperature, CC
In the field of D color cameras, the auto white balance method has become widespread. However, in the field of electronic endoscopes, the subject is often colored in a specific color, especially in industrial applications, such as rust due to rust, etc., and color temperature correction is good in auto white balance. Could not. Therefore, conventionally, the gain of the color signal is corrected by a fixed gain type to correct the color temperature. As described above, in the case of the electronic endoscope apparatus, it is difficult to employ the automatic white balance. When an endoscope observation device is used in combination with a light source device of a dimming method using lamp current control, if the light amount of the light source is changed during the observation, the color temperature of the color generated by the lamp changes accordingly. However, there is a problem that the color reproducibility changes. [0010] In the above-described integrated device of the CCU and the light source, if the brightness is changed by the integral knob 83, the exposure time changes, and the frame is moved forward during the observation of a moving image. In some cases, disadvantages may occur. In order to prevent this, it is necessary to move the aperture knob 82 in preference to the integral knob 83. However, from the viewpoint of the user, even if the integral knob 83 is turned,
Since the brightness can be controlled even by turning the aperture knob 82, the integration knob 83 is often moved before the aperture knob 82, so that the moving image observation ability is often reduced. The present invention has been made in view of the above circumstances, and in an apparatus having a function of processing an image pickup signal and adjusting the amount of illumination of a light source, prevents an erroneous operation by a user when adjusting the brightness of an image. It is another object of the present invention to provide a light source built-in type imaging device capable of improving operability. According to the present invention, there is provided:
Light source means for generating illumination light for irradiating the subject, imaging means for imaging the subject illuminated by the illumination light,
In a light source built-in type imaging apparatus having a signal processing unit for processing an output of the imaging unit, a light amount adjustment unit for adjusting an illumination light amount of the light source unit, and an electrical sensitivity of the imaging unit or an electrical control of the signal processing unit. There is provided means for changing one of the sensitivities, and setting means for setting the electrical sensitivity by the means for varying the electrical sensitivity in association with the adjustment of the illumination light quantity by the light quantity adjusting means. In the above arrangement, the light amount adjustment by the light amount adjusting means and the variable operation of the electric sensitivity by the electric sensitivity changing means are set by the setting means in association with each other. Does not allow the user to make a mistake. Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 relate to a first embodiment of the present invention. FIG. 1 is an external view of a signal processing device with a built-in light source that constitutes an imaging device with a built-in light source. FIG. 2 is a schematic configuration of the imaging device with a built-in light source. FIG. A built-in light source type signal processing device (hereinafter abbreviated as CCU) 1 shown in FIG. 1 constitutes a built-in light source type imaging device including an imaging means and the like. The CCU 1 is, for example, a CC as an imaging unit provided in the endoscope 2 shown in FIG.
D3 is electrically connected via the signal line 4a and the CCU connector 5. As shown in FIG. 2, the endoscope 2 irradiates the subject with illumination light from a light source lamp 6 built in the CCU 1 through a light guide 7 from an emission end thereof. The incident end of the light guide 7 is connected to an LG connector 9 shown in FIG. And the CC
In U1, between the entrance end of the light guide 7 and the light source lamp 6, an aperture 8 constituting light amount adjusting means for adjusting the illumination light amount is interposed. The CCU 1 controls a drive signal to the CCD 3 in order to control a charge accumulation time in the CCD 3, and has an exposure time control circuit 10 which constitutes a means for varying electric sensitivity. ing. The exposure time control circuit 10 is electrically connected via the CCU connector 5 and the signal line 4b. The exposure time control circuit 10 variably sets the exposure time of the CCD 3, and comprises an exposure variable resistor 11 which constitutes a setting means.
Is connected. Further, the CCU 1 has an aperture control circuit 12 constituting the light amount adjusting means for adjusting the aperture amount of the aperture 8. The aperture control circuit 12 variably sets the aperture amount of the aperture 8, that is, the illumination light quantity, and is connected to a light quantity variable resistor 13 constituting the setting means. The exposure variable resistor 11 and the light quantity variable resistor 13 are provided with a brightness control knob 14 shown in FIG.
In response, the resistance value changes. That is, the internal structure of the brightness control knob 14 is as shown in FIG. 2, and each resistor can be varied in one-axis two-interlock. This change in resistance value
The exposure time control circuit 10 and the aperture control circuit 1
2 are changed. Each MIN (minimum) of the exposure variable resistor 11 and the light quantity variable resistor 13 is grounded, and each MAX (maximum) is connected to the power supply VCC. Further, the center position and the MIN position of the exposure variable resistor 11 are short-circuited, and the center position and the MAX position of the light amount variable resistor 13 are short-circuited. And the brightness control knob 14 is
The left half variable area is an aperture variable area, and the right half is an exposure time variable area. In this way, the potential of the exposure resistor 11 is fixed at the GND potential at any position from the MIN of the knob 14 to the center, and becomes a constant value. Conversely, between the center and MAX, the potential of the light amount resistor 13 is VCC.
It is fixed at the potential and becomes a constant value. The exposure time control circuit 10 and the aperture control circuit 12 set an exposure time and an aperture amount according to a voltage according to the knob position. At the center position of the knob 14, the aperture 8 is opened, and the exposure time is set to the normal time. The CCU 1 converts a signal picked up by the CCD 3 into a process circuit 15 constituting signal processing means.
A predetermined process is performed. Although a circuit constituting signal processing means subsequent to the process circuit 15 is omitted, a TV signal is finally output. In the above configuration, when the user attempts to control the brightness, the operation is to operate the brightness control knob 14. Since the knob 14 is divided into a variable aperture area and a variable exposure time area, for example, if the knob is located between the MIN and the center, the knob 14 is turned to the right when the user tries to make it even brighter. . Until the knob position exceeds the center position, only the aperture moves toward opening, and the exposure time does not change. When the brightness is not enough, and when the knob is set between the center and MAX, the aperture is already open, and the insufficient brightness is compensated for by changing the exposure time. On the other hand, when it is desired to darken the image, the operation is reversed. First, the exposure time is returned to the normal time, and if the exposure time is still insufficient, the aperture is closed. In this embodiment, unlike the conventional example, there is no aperture knob and no integral control knob, and the brightness control knob 14 is integrated. Therefore, since the brightness is adjusted by the knob 14 as a mechanically interlocked setting means, it is possible to completely prevent an erroneous operation such as changing the exposure time while narrowing the aperture and increasing the brightness when the brightness is desired, and simplifying the operation. Operability is improved. FIGS. 3 and 4 relate to a second embodiment of the present invention. FIG. 3 is an external view of a signal processing device with a built-in light source which constitutes an imaging device with a built-in light source. FIG. FIG. The CCU 21 of the second embodiment differs from the first embodiment in that a GCA (gain control amplifier) is used instead of the exposure time control circuit 10 as means for electrically varying the sensitivity. ing. In addition, the same configurations and operations as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The CCU 21 has a GCA variable resistor 11A having a similar configuration in place of the exposure variable resistor 11 of the first embodiment. Further, the CCU 21 is:
A GCA 22 is connected to a stage subsequent to the process circuit 15, and a gain control terminal of the GCA 22 is connected to the GCA 22.
The variable terminal of the variable resistor 11A is connected. The output of the GCA 22 is output as a standard TV signal via the encoder 23. Further, the CCU 21 has a brightness control knob 24 whose right half is used for GCA adjustment, instead of the knob 14 of the first embodiment. The output from the GCA 22 tends to degrade the S / N ratio as the sensitivity increases. For this reason, the brightness is usually adjusted by varying the aperture amount as in the first embodiment, and at this time, the GCA is a standard setting. And
In the above configuration, when the aperture becomes insufficient even when the aperture is opened, the brightness is supplemented by GCA. Therefore, the brightness can be adjusted from the first stage of the brightness adjustment without deteriorating the S / N ratio. In this embodiment, the means for varying the electrical sensitivity of the signal processing means and the light quantity adjusting means are set and controlled in association with each other, so that erroneous operations by the user in brightness adjustment can be prevented. ,
Operability is improved. In the first and second embodiments, the control is performed by the electric sensitivity variable means and the light quantity adjusting means which are mechanically linked, but the microcomputer and the variable resistor for level setting are used.
By controlling the variable resistance value with the microcomputer, the means for electrically varying the sensitivity and the light amount adjusting means can be electrically linked. In this configuration, in addition to the effects described above, a special double variable resistor that is mechanically interlocked is not required, so not only is there a high degree of freedom in design, but also space is saved and the size is reduced. There is. FIGS. 5 to 7 relate to a third embodiment of the present invention. FIG. 5 is a block diagram of an image pickup apparatus, FIG. 6 is a view showing a relationship between LUT data and a lamp current, and FIG. It is a block diagram in the case of applying to an electronic endoscope apparatus. The image pickup apparatus according to the present embodiment performs the P.P. control based on a dimming control signal from operation means (not shown). W. M
(Pulse width modulation) The current controller 32
To control the lamp current supplied to the This lamp 33
In the above, the amount of emitted light changes depending on the lamp current. On the other hand, a CCD 35 as an image pickup means is driven by a drive circuit 36, and at the same time, picks up an image of a subject illuminated by a lamp 33, converts the image into an electric signal, and outputs the electric signal. The output of the CCD 35 is sent to a process circuit 37, which outputs a luminance signal Y and a color difference signal R.
-Y and BY are converted. The color difference signals RY and BY are sent to a RY GCA (gain control amplifier) 38 and a BY GCA 39 for color temperature correction, gain corrected, and sent to an encoder 40. Output as a standard television signal. The lamp current, during its return,
The current value is detected by a current value detection circuit 41, and the detected current value is sent to an S / H (sample / hold) circuit 42. The detected current value of the lamp current is S /
Sampled / held by the H circuit 42, A / D converted by the A / D converter 43, and converted into digital data,
M. U. T (lookup table) 44 is sent. The above L. U. In T44, the RY signal and B corresponding to the lamp current value are approximated by a polygonal line as shown in FIG.
A gain correction value for the -Y signal is generated, and the R-Y GCA3
8 and the correction value is sent to the BY GCA 39. The RY
In GCA38 and BY GCA39, L.G.
U. Based on the gain correction value given from T44, RY
The color temperature is corrected by correcting the gain of the signal and the BY signal. In the above configuration, when a dimming control signal from the operating means (not shown) changes, the P.D. W.
The lamp current is changed by the M current controller 32, and the lamp 3
The color temperature of the emission color 3 changes. At this time, as the emission color temperature of the lamp 33 changes, the color component of the output of the CCD 35 also changes.
The RY and BY signals generated by the process circuit 37 also change. On the other hand, the lamp current value detected by the current value detection circuit 41 passes through the S / H circuit 42 and the A / D converter 43 to the L.P. U. T44. U. T44
Output a correction value. This correction value changes according to the lamp current value, and the RY GCA 38 and the BY GCA
The values 39 and 39 are such values as to correct the RY and BY output changes of the process circuit 37 due to the change in the color temperature of the lamp-generated color. Therefore, the process circuit 37
The RY and BY signals output from the RY G
The change in the emission color temperature of the lamp 33 is corrected by the CA 38 and the BY GCA 39, and the corrected signal is sent to the encoder 40 as a signal having an appropriate value. This embodiment utilizes the fact that the lamp current is correlated with the color temperature of the lamp emission color, and corrects the color signal gain by the lamp current, thereby correcting the color difference signal even when the lamp current changes. Therefore, the color reproducibility can be stabilized without any change. For example, when dimming by changing the lamp current of the light source, the gain of the color signal is also corrected so as to follow the change in the color temperature of the lamp emission color.
A good state can be maintained without changing the color reproducibility. FIG. 7 is an overall configuration diagram when the device of the third embodiment is applied to an electronic endoscope device. In the electronic endoscope device shown in FIG. 7, an electronic endoscope 46 is connected to an integrated light source and CCU image pickup device 45. The output of the image pickup device 45 is sent to a monitor device 47, The subject image picked up by the endoscope 46 can be observed by the monitor device 47. The power of the imaging device 45 is supplied by a battery device 48. The imaging device 45 includes a main switch 49, the LG connector 9, the CCU connector 5, and a brightness adjustment 14
(Or 24) is provided. The endoscope 46 and the imaging device 45 are connected via a universal cord 50 and a connector 51 provided at an end thereof. Incidentally, reference numeral 52 denotes a subject. The same components and operations as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Conventionally, the light source device of the endoscope controls the light amount by means of a diaphragm. However, in this embodiment, a lamp current control type light amount adjusting means can be used, and it is not necessary to always make the lamp emit full light. Thus, the use time of the electronic endoscope apparatus using the battery power can be greatly increased. Alternatively, the size of the battery can be reduced, and the performance during portable use can be significantly improved. FIG. 8 is an overall configuration diagram of an electronic endoscope apparatus according to a fourth embodiment of the present invention. The present embodiment is different from the third embodiment shown in FIG. 7 in that the image pickup device is configured separately from a light source device 55 and a camera control unit (CCU) 56. In this embodiment, the current value detection circuit 41, S / H circuit 42, A / D converter 43, L. U.
The T44 and the like are built in either the light source device 55 or the CCU 56. In the example described below,
It is assumed that only the current value detection circuit 41 is arranged in the light source device 55, and the other components are arranged in the CCU 56. Then, the current value which is the output of the current value detection circuit 41 in the light source device 55 is sent to the CCU 56 via the cable 53,
It works. The other constructions, functions and effects are the same as those of the third embodiment, and the description is omitted. Further, the present invention is not limited to the electronic endoscope apparatus shown in the third and fourth embodiments, but also includes a camera head separated type which is used in combination with a light source apparatus for adjusting a light amount by controlling a lamp current. The present invention can be applied to all imaging devices including an imaging device. [Supplementary Note 1] The imaging device with a built-in light source according to claim 1, wherein the light amount adjusting unit includes a mechanical configuration for adjusting the illumination light amount, and the electric sensitivity changing unit includes:
A mechanical configuration for varying the electrical sensitivity, wherein the setting unit associates the adjustment by linking each mechanical configuration of the light amount adjusting unit and the electrical sensitivity varying unit. Settings. [Supplementary Note 2] In the image pickup apparatus with a built-in light source according to claim 1, the light quantity adjusting means includes an electric configuration for adjusting the illumination light quantity, and the means for changing the electric sensitivity includes: An electrical configuration for varying the electrical sensitivity, wherein the setting unit associates the adjustment by linking each electrical configuration of the light amount adjusting unit and the electrical sensitivity varying unit. Settings. [Supplementary Note 3] In the light source built-in type imaging device capable of adjusting the light amount of the illumination light and the electric sensitivity of the video signal from the imaging means, the adjustment range of the light amount and the adjustment range of the electric sensitivity Are included in a range in which one adjustment value can be adjusted, and the adjustment of the light amount and the adjustment of the electrical sensitivity can be adjusted by one adjustment means. [Supplementary Note 4] In the light source built-in type imaging device capable of adjusting the light amount of the illumination light and adjusting the electric sensitivity of the video signal from the image pickup means, the adjustment range of the light amount is the adjustment range of the electric sensitivity. One adjustment value is included in the adjustable range so that the adjustment can be made earlier. [Supplementary Note 5] In the light source built-in type imaging device capable of adjusting the light amount of the illumination light and adjusting the electrical sensitivity of the video signal from the imaging means, the adjustment range of the light amount is the adjustment range of the electrical sensitivity. The adjustment of the light amount and the adjustment of the electrical sensitivity can be adjusted by a single adjustment unit so that the adjustment can be performed earlier than the adjustment of the light amount, within the adjustable range of one adjustment value. [Supplementary Note 6] In the imaging device with a built-in light source according to claim 1, the setting means adjusts the brightness from a low level to a predetermined value by adjusting the light amount, and adjusts the predetermined brightness. Adjustment from a value to a high level is performed by adjusting the electrical sensitivity to make the associated setting. The apparatus according to Supplementary Note 6, wherein the brightness adjustment of the image projected based on the video signal output by the imaging unit is adjusted as a single unit without being conscious of switching between the adjustment of the light amount and the adjustment of the electrical sensitivity and the relevance. it can. [Supplementary Note 7] In the imaging apparatus for generating illumination light for irradiating a subject and an imaging device for capturing an image of a subject illuminated by the illumination light and generating a video signal of the subject image by a signal processing means, A light amount adjusting unit that adjusts an illumination light amount at the light source unit by controlling an electric signal supplied to the unit and the light source unit; a signal value detecting unit that detects a value of the electric signal supplied to the light source unit; Based on the signal value detected by the signal value detection means,
Correction signal generating means for generating a correction signal set based on the correlation between the color temperature of the light source means and the signal value; and a video signal in the signal processing means according to the correction signal generated by the correction signal generating means. Color information correction means for correcting the gain of the color information. In the apparatus described in Appendix 7, the electric signal supplied to the light source means is directly controlled by the light amount adjusting means, so that the color reproducibility can be improved. [Supplementary Note 8] In the imaging device according to Supplementary Note 7, the light amount adjusting unit controls a current value as an electric signal supplied to the lamp as the light source unit by PWM (pulse width modulation) control. [Supplementary Note 9] In the imaging apparatus according to supplementary note 7, the correction signal generating means stores a correction value set in accordance with the signal value. U. T (look-up table), and the color information correcting means includes the L.T. U. GCA that varies the gain according to the correction value of T
(Gain control amplifier). According to the imaging device with a built-in light source of the present invention,
In a device having a function of processing the output of the imaging means and adjusting the amount of illumination light of the light source means, when adjusting the brightness of an image, it is possible to prevent a user's erroneous operation and improve the operability. is there.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 relate to a first embodiment, and FIG. 1 is an external view of a signal processing device with a built-in light source constituting an imaging device with a built-in light source. FIG. 2 is a schematic configuration diagram of an imaging device with a built-in light source. 3 and 4 relate to a second embodiment, and FIG. 3 is an external view of a signal processing device with a built-in light source that constitutes an imaging device with a built-in light source. FIG. 4 is a schematic configuration diagram of an imaging device with a built-in light source. 5 to 7 relate to a third embodiment, and FIG. 5 is a block diagram of an imaging apparatus. FIG. 6 is a diagram showing a relationship between LUT data and a lamp current. FIG. 7 is a configuration diagram when the device of the third embodiment is applied to an electronic endoscope device. FIG. 8 is an overall configuration diagram of an electronic endoscope apparatus according to a fourth embodiment. FIG. 9 is an external view of a CCU according to a conventional example. FIG. 10 is an overall configuration diagram of an imaging device according to a conventional example. [Description of Signs] 1 CCU 2 Endoscope 3 CCD 6 Lamp 7 Light guide 8 Aperture 10 Exposure time control circuit 11 Exposure variable resistor 12 Aperture control circuit 13 Variable light resistance Table 14: Brightness control knob

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-70071 (JP, A) JP-A-60-10882 (JP, A) JP-A-5-316408 (JP, A) JP-A-1- 191582 (JP, A) JP-A-5-252451 (JP, A) JP-A-5-252450 (JP, A) JP-A-3-153208 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 1/00-1/32 H04N 5/222-5/257

Claims (1)

(57) [Claim 1] Light source means for generating illumination light for irradiating an object, imaging means for imaging an object illuminated by the illumination light, and processing of the output of the imaging means In a light source built-in type imaging device having a signal processing unit, a light amount adjustment unit for adjusting an illumination light amount of the light source unit, and a unit for changing one of an electrical sensitivity of the imaging unit and an electrical sensitivity of the signal processing unit. A light source built-in type imaging apparatus, further comprising setting means for setting the electric sensitivity by the means for varying the electric sensitivity in association with the adjustment of the illumination light quantity by the light quantity adjusting means.