JP2643948B2 - Electronic endoscope device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus provided with a means for performing white balance corresponding to a connected electronic endoscope.

[Related Art] In recent years, by inserting an elongated insertion portion into a body cavity, it is possible to observe an affected part in the body cavity or the like using an observation means provided in the insertion portion without necessitating an incision. Accordingly, endoscopes capable of performing a treatment by inserting a treatment tool into a forceps channel have been widely used.

In the endoscope described above, an image guide fiber is used for image transmission. Recently, a solid-state image pickup device (abbreviated as SID) such as a CCD is housed at the distal end of the insertion section to form an image pickup means. An electronic endoscope (hereinafter, referred to as an electronic endoscope or an electronic scope) that transmits a signal photoelectrically converted by an imaging element through a cable and can display a color image on a monitor device will be put to practical use. Became.

Incidentally, in the electronic endoscope, white balance adjustment is required. In other words, when capturing a white subject,
Either electrically or mechanically changing the sequential irradiation time of the color separation / rotation filter in the light source device so that the R, G, B ratio of the CCD output signal becomes 1, or adjust the gain of each of the CCD output signals. Was changed to match. A more accurate expression of the white balance is defined by an output signal from the device to a display monitor or the like. For example, the ratio of R, G, B output signals is set to 1 or (RY), (NTSC system). The color difference signal output of BY) is set to 0. That is, the chrominance signal modulated by the subcarrier is set to “0” when capturing a “white” subject.

FIG. 13 shows a conventional white balance adjusting means of a mechanical system.

As shown in the figure, a rotary filter 1 is driven to rotate by a motor 2, and the fan-shaped red, green, and blue color transmission filters formed on the rotary filter 1 by this rotation, that is, R filters 3R, G filters 3G, B The filter 3B is interposed across the light beam 4 of the light source lamp (not shown), that is, in the middle of the optical path. When each of the color filters 3R, 3G, 3B is interposed, the subject is illuminated with light of red, green, and blue colors separated through a light guide, and the imaging output captured by the CCD is a light guide and a CCD. When the spectral sensitivity characteristics of the above are fixed, it depends on the amount of irradiation, that is, the irradiation time (exposure time). Therefore, the aperture ratio of R, G, B of the rotary filter 1,
In other words, the white balance is adjusted by changing the length of the fan in the fan shape. For example, if the R, G, B ratio at the CCD output becomes 1,
Assuming that white balance can be achieved with the R, G, B and NTSC outputs as device outputs, a white object is imaged. If the CCD output in that case is as shown in FIG. For the filter 3R, the fan length is increased to increase the aperture ratio, while for the B filter 3B, the fan length is reduced to reduce the aperture ratio, and as shown in FIG. The white balance is adjusted so that the ratio of R, G, and B in the output becomes 1.

On the other hand, there is a type in which white balance is adjusted by electrically changing the exposure time.

The electric adjustment type includes a type in which the light of the light source lamp is continuously lit and a type in which the light source lamp is intermittently illuminated by a pulse. In the latter case, for example, FIG. 15 (a)
As shown in FIG. 4B, when the white light is illuminated with the same number of pulses (for example, 5 pulses) and transmitted through the R, G, and B filters to illuminate a white subject, the CCD output is R, When the ratio of G and B deviates from 1, the white balance is deviated. In this case, as shown in FIG. 15 (c), for example, by increasing the number of light emission pulses in the R filter and decreasing the number of light emission pulses in the B filter with respect to the G filter, and illuminating the light. The exposure amount can be changed, and as a result, the R, G, B signals whose CCD outputs are white-balanced as shown in FIG.
Incidentally, in this conventional example, the numerical aperture of each color filter is assumed to be constant.

FIG. 16 shows a conventional example in which the gain of a CCD output signal is adjusted to perform white balance adjustment.

Electronic endoscope device 11 with white balance adjustment function
Is an electronic endoscope 12 in which imaging means is incorporated, a light source unit 13 that supplies illumination light to the electronic endoscope 12, and a video signal that can display a signal imaged by the electronic endoscope 12 on a display device. And a signal processing unit 14 for conversion.

The electronic endoscope 12 has an elongated insertion part 15 formed so as to be easily inserted into a body cavity, and an imaging lens by arranging an objective lens 16 and a CCD 17 as a solid-state imaging device at a distal end side of the insertion part 15. Is incorporated.

Further, a light guide 18 for transmitting illumination light is inserted into the insertion portion 15 to transmit the illumination light supplied from the light source unit 13 and to emit the illumination light from the front end surface. It is expanded by the lens 19 to illuminate the subject 21 side.

The light source unit 13 that supplies illumination light to the proximal end face of the light guide 18, a light source lamp 22, and a lens 23 that collects and irradiates the illumination light of the light source lamp 22 to the end face of the light guide 18,
An RGB rotation filter 24 interposed in the optical path between the lens 23 and the end face of the light guide 18;
And a motor 25 for rotationally driving the motor.

The rotation filter 24 is configured to emit light in each of red, green, and blue wavelength ranges,
That is, red, green, and blue transmission filters 24R, 24G, and 24B that transmit R, G, and B, respectively, are formed in a fan shape, and by rotating the rotation filter 24, each of these R, G, and B3 primary colors is formed. The light is illuminated in a sequential manner. This rotation filter
The rotation of a motor 25 that rotates 24 is controlled by a rotation servo circuit 27. The rotation servo circuit 27
The rotation of 25 is synchronized with the frame frequency of the video signal.

The subject 21 illuminated in a plane-sequential manner with each of the R, G, and B lights was imaged on the imaging surface of the solid-state imaging device by the CCD 17 with the objective lens 16, and was photoelectrically converted by applying a read clock signal by the CCD driver 28. The signal is read. This clock signal and the signal of the rotary servo circuit 27 are
Are synchronized with the synchronization signal output from the

The output signal of the CCD 17 is amplified by a preamplifier 31 forming the signal processing unit 14, is input to a reset noise removing circuit 33 via an isolation circuit 32 for protecting the patient from electric shock or the like, and reset noise is removed. Thereafter, unnecessary high frequencies such as 1 / f noise and CCD carrier are removed through a low-pass filter 34, white balance adjustment is performed by a white balance adjustment circuit 35, and further, γ correction is performed by a γ correction circuit 36, that is, the image is displayed on a display tube. The non-linearity of the electric / optical conversion system in this case is corrected and input to the A / D converter 37. The electric signal-to-light conversion characteristic of the television picture tube is not linear, and normally γ = 2.2. This γ correction circuit is used to correct the non-linearity to a linear characteristic throughout the system via the electronic endoscope. The input / output characteristics of 36 are usually γ =
The reciprocal of 2.2, that is, γ = 0.45 is set.

The A / D converter 37 converts the digital signal into a digital signal, and the frame memories 38R and 38 corresponding to the frame-sequential illumination.
G and 38B are respectively written for one frame. That is,
For example, an image is captured under illumination with red light through the red transmission filter 24R, and a signal read from the CCD 17 is written to the frame memory 38R. Then, each frame memory 38
When one frame of image data is written to R, 38G, and 38B, these are read out at the same time, converted to analog signals by a D / A converter 39, and unnecessary high frequencies are removed by a low-pass filter 41. Output amplifier 42
Is input to The conversion speed of the A / D converter 37 and the writing and reading of data to and from the color frame memories 38R, 38G, 38B are controlled by output signals from the memory control circuit 43. The output signal of the memory control circuit 43 is generated in synchronization with the synchronization signal of the synchronization signal generation circuit 29.

The R, G, B color signals passed through the output amplifiers 42 are output from primary color signal output terminals having an output impedance of 75Ω. The composite synchronizing signal of the synchronizing signal generating circuit 29 is also output from the synchronizing signal output terminal via the output amplifier 44.

By the way, the white balance adjustment circuit 35 can variably adjust the output gain of the signal passed through the white balance adjustment circuit 35 by the white balance adjustment unit 45. The white balance adjustment circuit 35 including the adjustment unit 45 has, for example, a configuration as shown in FIG.

The non-inverting input terminal of the differential amplifier 47 forming the gain control amplifier is connected to the input terminal of the white balance adjustment circuit 35, and the inverting input terminal is connected to the output terminal thereof via a resistor RL, and is variable. Grounded via a resistor R1 and a switch S1, a resistor R2 and a switch S2, a variable resistor R3 and a switch S3.

As the signal Vi input from the input terminal, for example, as shown in FIG. 18 (a), signals VR, VG, VB captured under R, G, B sequential illumination are applied, and the differential amplifier 47 the output signal V ₀ from the output terminal after being amplified through is output.

The switches S2, S2, S3 are turned on and off by a control signal. For example, the switches S1, S2, S3 are connected to the input signal VR as shown in FIGS. 18 (b), (c), (d). , VG,
It goes to “H” level during the period when VB is input. It is turned on by the R, G, B control signals, and is kept off at other "L" levels. Therefore, for the signals VR, VG, VB, the inverting input terminals are grounded via the resistors R1, R2, R3, respectively, so that the gain for the input signals VR, VG, VB is (1 + RL / R
1), (1 + RL / R2), and (1 + RL / R3).

Therefore, the gain of the other two input signals VR and VB is variably adjusted by the variable resistors R1 and R3 with respect to the level of the input signal VG. The white balance is performed so as to be equal to the signals VR, VG, and VB.

[Problems to be Solved by the Invention] In the above-described conventional example, in an electronic endoscope apparatus using a scope using the same CCD, the white balance adjusting means in the main body signal processing device is fixed or The only additional function is manual adjustment by the user.

As a result, in a scope having different lengths, a light guide for transmitting illumination light to a subject changes in spectral characteristics depending on the length, and a sufficient white balance is not obtained.

It is needless to say that the conventional method cannot cope with a scope using a different CCD.

On the other hand, in Japanese Patent Application Laid-Open No. 61-2120, an endoscope identification parameter generation circuit, a timing pulse control circuit for the SID, a setup circuit for adjusting the gain, flare and black level characteristics of the SID are provided on the scope side. A conventional example has been disclosed in which an adjustment mechanism is provided so as to be compatible with various types of scopes and SIDs.

However, in this conventional example, the scope has a mechanism for adjusting the control signal corresponding to the scope or SID on the scope side, which complicates the structure of the scope, increases the number of parts in each scope, and increases the number of manufacturing steps. And the manufacturing cost increases. In addition, the scope becomes larger and heavier, making it difficult to operate, and the operability is reduced. In addition, it does not disclose a white balance adjusting unit corresponding to the light transmission characteristics of the light guide.

The present invention has been made in view of the above points, and does not require providing various adjustment mechanisms on the scope or complicating the structure of the scope. It is another object of the present invention to provide an endoscope apparatus which can cope with the above problem and does not reduce operability.

[Means for Solving the Problems and Action] In the present invention, the information signal generating means relating to the overall spectral characteristics of the electronic scope or the information relating to the white balance adjustment required by the overall spectral characteristics is provided on the electronic scope side. Each type of electronic signal is provided by providing a means for generating a classification signal for classification, and a means for decoding the information signal or the signal for identification and performing a white balance adjustment corresponding to the connected electronic scope. Even if the spectral characteristics of the CCD or the light guide of the scope are different, and thus the overall spectral characteristics are different, the white balance adjustment suitable for the electronic scope actually connected can be performed.

EXAMPLES Hereinafter, the present invention will be described specifically with reference to the drawings.

1 to 8 relate to a first embodiment of the present invention, FIG. 1 is a configuration diagram of an electronic endoscope apparatus of the first embodiment, FIG. 2 is a schematic side view of the first embodiment, FIG. 3 is a perspective view showing a connector and a connector receiver, FIG. 4 is a circuit diagram of a scope discriminating circuit, FIG. 5 is a characteristic diagram showing a transmission characteristic of a light guide, and FIG. 6 is a block diagram showing a configuration of an RGB synchronizing circuit. FIG. 7 is a circuit diagram showing a specific example of the white balance adjustment circuit, and FIG. 8 is a timing chart for explaining the operation of the white balance adjustment circuit.

As shown in FIG. 2, the electronic endoscope device 51 of the first embodiment
Is an electronic endoscope (electronic scope) incorporating an imaging means
52, a signal processing device (also referred to as a video processor) 53 containing light source means for supplying illumination light to the electronic scope 52 and a signal processing means, and a video signal output from the signal processing device 53. And a monitor 54 for color display.

In the electronic scope 52, a flexible and elongated insertion portion 55 is formed so as to be easily inserted into a body cavity or the like, and a wide operation portion 56 is formed at a rear end side of the insertion portion 55. A flexible universal cord 57 extends laterally from the portion 56.
At the end of the universal cord 57, a connector 58 is provided. On the other hand, the signal processing device 53 containing the light source unit 59 and the signal processing circuit unit 61 (see FIG. 1) can be connected to the connector 58. A receiver 62 is provided.

On the distal end side of the insertion portion 55, a rigid distal end portion 63 and a bending portion 64 that can be bent rearward adjacent to the distal end portion 63 are sequentially provided. By rotating a bending operation knob 65 provided on the operation section 56, the bending section 64 is rotated.
Can be bent vertically and horizontally. In addition, the operation section 56 is provided with an insertion port 66 through which a treatment instrument channel provided in the insertion section 55 is inserted.

As shown in FIG. 1, an image pickup objective lens 67 and a CCD 68 serving as a solid-state image pickup device disposed on the focal plane of the objective lens 67 are housed in the distal end portion 63 of the insertion portion 55 for imaging. Means are incorporated.

A light guide 69 for transmitting illumination light is inserted into the insertion portion 55 to transmit the illumination light supplied from the light source unit 59 and to emit the illumination light from the front end face. The lens 70 is expanded to illuminate the subject 71 side.

A light source unit 59 for supplying illumination light to the near-side incident end face of the light guide 69 includes a light source lamp 72,
A lens 73 for condensing and illuminating the illumination light on the incident end face of the light guide 69, a rotary filter 74 interposed in the optical path between the lens 73 and the incident end face of the light guide 69, and rotating the rotary filter 74. It comprises a motor 75 to be driven and a rotary servo circuit 76 for controlling the number of rotations of the motor 75.

The light source lamp 72 emits white light, such as a xenon lamp, and has an emission spectrum distribution close to blackbody radiation.

The rotation filter 74 includes three fan-shaped color transmission filters 74R, 74G, and 74B.
G and 74B have characteristics of transmitting the red, green and blue wavelength ranges R, G and B, respectively.

As shown in FIG. 1, the illumination light of the light source lamp 72 is a lens.
The light is condensed at 73 and emitted toward the incident end face of the light guide 69, but a rotary filter 74 rotated by a motor 75 is interposed in the optical path. That is, the rotation filter
By rotating 74, the lens 73 and the light guide
The subject 71 is, for example, R, G, B, R,... By the light in the wavelength range passed through the color transmission filter (the blue transmission filter 74B in FIG. Illuminated sequentially.

The rotation speed of the motor 75 that rotates the rotation filter 74 is
The rotation servo circuit 76 controls the phase to be synchronized with the frame frequency (for example, 29.97 Hz) of the synchronization signal generation circuit 77.

An object 71 illuminated in a plane-sequential manner with each of the R, G, and B lights is imaged on an imaging surface of a CCD 68 by an objective lens 67, and a CCD driver 78
, A signal that has been photoelectrically converted by the application of the read clock signal is read. In addition, this clock signal is output.
The CCD driver 78 and the rotary servo circuit 76
Synchronized with the synchronization signal of 7.

The output signal of the CCD 68 is amplified by a preamplifier 81 forming a signal processing circuit unit 61, is input to a reset noise removal circuit 83 through an isolation circuit 82 that protects from electric shock or the like to a patient, and is used to improve S / N. 1 / f noise and reset noise are removed. After that, unnecessary high-frequency waves such as a CCD carrier are removed through a low-pass filter 84 and input to a white balance adjustment circuit 85. The white balance is adjusted by the white balance adjustment circuit 85, and further, the γ correction circuit 86 performs γ correction, that is, non-linearity of the electric-optical conversion system when displaying on a display tube or the like (normally γ = 2.2). (For example, γ = 1 /
2.2 = 0.45) is input to the A / D converter 87. The A / D converter 87 converts the signal into a digital signal, and the signal captured under the frame-sequential illumination is written into the frame memories 88R, 88G, and 88B for one frame. That is, for example, an image is captured under illumination with red light through the red transmission filter 74R, and the signal read from the CCD 68 is written to the frame memory 88R. When one frame of image data is written into each of the frame memories 88R, 88G, and 88B, they are read out at the same time, converted into analog signals by the D / A converter 89, and further converted by the low-pass filter 91 into unnecessary high-frequency signals. Is removed and D /
R, G, B smoothed signal discontinuities during A conversion
Signal. Thus, the R, G, and B signals are respectively input to the output amplifier 92.

The conversion speed of the A / D converter 87 and the writing and reading of data to and from the frame memories 84R, 84G and 84B are controlled by output signals from the memory control circuit 93. The output signal of the memory control circuit 93 is generated in synchronization with the synchronization signal of the synchronization signal generation circuit 77.

The color signals R, G, B amplified by the output amplifier 92 are respectively output from output terminals having an output impedance of 75Ω. The synchronization signal of the synchronization signal generation circuit 77 is also output from the output amplifier 94.
, And is amplified and output from the synchronization signal output terminal.

By the way, in the first embodiment, each scope 52
The connector 58 attached to the universal cord 57 of
As shown in FIG. 4 or FIG. 4, the signal processing device 53 comprises a light source connector 101, a signal connector 102, and a discrimination connector 103, while the signal processing device 53 has a light source connector receiver 104 and a signal connector receiver 104 to which these connectors 101, 102, 103 can be connected. 105,
It has a connector receiver 62 provided with a connector connector 106 for determination.

Note that the light source connector 101 is actually provided with an air supply / water supply connector in addition to the light guide connector, and the signal processing device 53 has a structure capable of connecting them. In FIG. 1, the air / water supply means is omitted.

The connector 58 has a connector receiver 62 of a signal processing device 53.
Next, a discriminating connector 10 for discriminating or identifying the type related to the spectral characteristic of the connected scope 52
3 is provided. Thus, by the connection of the discriminating connector 103, the scope discriminating circuit 111 identifies the kind of the overall spectral characteristic of the connected scope 52 and the like, and is used to perform white balance adjustment according to the scope 52. I have to.

The discriminating connector 103 includes, for example, six contact pins P1, P2,..., P6 as shown in FIG.
5 is connected to the ground terminal P6 or left open depending on the length and material of the CCD 68 and the light guide 59 used for the scope 52.

The pins P1 and P2 in the top row are used for CCD discrimination.
For example, three types of CCDs that can be within 2 bits with one pin P1 and P2
Is used as a code for determining the type of.

In other words, CCDs have different spectral characteristics depending on the type,
Which of the three types of CCD used for the scope is represented by the states of the pins P1 and P2.

The pins P3, P4, and P5 in the second row are used for determining the scope length, and three bits represent eight types of scope lengths.

The scope length indicates the length of the light guide used for the scope and its material. As shown in FIG. 5, the length of the light guide (for example, LG2m and LG4m are 2 m and 4 m, respectively). ), The transmittance characteristics (spectral characteristics) are different, which affects the white balance.

Therefore, in this embodiment, the pin P for determining the scope length is used.
3, P4 and P5 indicate the light guide length and type used for the scope.

In the scope 52 of this embodiment, the connector 103 for discrimination shown in FIG. 4 has the pins P1 and P5 connected to the ground terminals, identifies the spectral characteristics of the scope corresponding to this connection, and responds to the spectral characteristics. By performing white balance correction as a correction amount, white balance can be achieved.

The discrimination connector receiver 106 to which the discrimination connector 103 is connected has a scope discrimination circuit 111 as shown in FIG.
Is provided.

That is, the pin receiver connected to the pin PI (I = 1, 2,... 5)
QI is connected to the power supply terminal Vcc via the resistor R and to one (non-inverting) input terminal of the comparator CI. The other inverting input terminal of each comparator CI is connected to a ground terminal or a slightly higher level (ground level in the figure). Thus, a "Hi" or "Low" discrimination signal is output depending on whether or not the level of one input terminal exceeds the reference level of the other input terminal. Thus, depending on the combination of the judgment output OI of the comparator CI, the connected scope 52
A determination signal for white balance correction corresponding to the type of the spectral characteristic is generated. In the example of FIG. 4, pins P1 and P5
Is connected to the ground terminal P6.
In the discrimination signal outputs Q1 to Q5 of C1 to C5, Q1 and Q5 are “Low” and the others are “Hi”. Such a discrimination signal is input to the RGB synchronizing circuit 112 as shown in FIG. 1, and generates a control signal for changing the gain of the white balance adjustment circuit 85 with respect to the RGB input signal to perform white balance.

The RGB synchronizing circuit 112 outputs a gain control signal to the white balance adjustment circuit 85 in synchronization with the timing at which the R, G, and B signals are input by the RGB switching signal input from the rotation servo circuit 76.

As shown in FIG. 6, the RGB synchronizing circuit 112 includes an R gain selection circuit 114R and a B gain selection circuit to which 5-bit determination signal data output from the scope determination circuit 111 is input.
The R gain selection circuit 114R, the B gain switching circuit 114B, and the G gain setting circuit 11
And an RGB switching circuit 116 that switches between 5G and 5G and outputs it as a 5-bit gain control signal.

In this case, the gain of the G signal is fixed to, for example, “1”, and the R and B signals are output with a gain control signal that is changed relatively thereto.
The R gain adjustment circuit 114R outputs an R gain control signal for white balance adjustment corresponding to the spectral characteristic determined by the input discrimination signal data. In other words, since the output data of the scope discriminating circuit 111 corresponds to the type representing the overall spectral characteristics of the scope, the extent to which the gain of the R signal should be set in the case of the spectral characteristics is determined in advance in the ROM. (Not shown), and by reading the written data, the gain control signal data for the R signal can be output. In this case, since the G signal is set to 1, the magnitude of the gain control signal data for the R signal is relatively determined by the G gain control signal data. B
The gain selection circuit 114B can also be configured in a similar manner.

The white balance adjustment circuit 85 for adjusting the white balance by the gain control signal has, for example, the configuration shown in FIG.

A pair of NPN transistors T1, forming a differential amplifier
The R, G, B signals are applied to one base of T2 via a DC blocking capacitor C. The bases of the transistors T1 and T2 are grounded via a bias resistor Rb, the respective emitters are connected to a negative power supply terminal -Vcc via respective resistors Re1 and Re2, and the respective collectors are directly connected to a load resistor. Connected to the positive power supply terminal Vcc via Rl. The other transistor T
The collector of 2 is connected to the base of a transistor T3 forming an emitter follower, the collector of this transistor T3 is connected to the positive power supply terminal Vcc, and its emitter is connected to a resistor Re3.
, And to the negative power supply terminal -Vcc, and to the output terminal of the white balance adjustment circuit 85.

The series connection of the switch S1 and the resistor R1, the switch S2 and the resistor R2,..., The switch S5 and the resistor R5 is connected between the emitter of the one transistor T1 and the emitter of the other transistor T2. , S5 are turned on and off by a 5-bit gain control signal output from the RGB synchronizing circuit 112, and the combined resistors on the emitter side when some of these resistors R1,. And the gain of the white balance adjustment circuit 85 is changed to perform white balance adjustment.

The resistors R1 to R5 shown in FIG.
The resistor whose on / off is controlled by B is R1, and R2 = R1 / 2,
^{R3 = R1 / 2 2, R4} = R1 / 2 3, R5 = R1 / 2 4 (R5 is the MSB of the gain control signal.) Set to. In this case, the gain _GL of the white balance adjustment circuit 85 is approximately Rl / (R1 to R5
And the combined value of the resistors turned on). For example, when only the LSB of the gain control signal is “Hi” (only the switch S1 is on), _GL = Rl / R1. When only the MSB is “Hi” (the switch S5 is on), _GL = Rl / R5, and the maximum gain _GL is obtained when the MSB is “Hi”. Note that the change width of the gain _GL is the RSB R
5-bit resolution ( ²⁵ = 32 steps) from l / R1 to MSB Rl / R5.

RGB synchronizing circuit 112 and white balance adjusting circuit
The operation of 85 is as follows.

For example, when a white subject is imaged, the R, G, B as shown in FIG.
It is assumed that the signal is input to the white balance adjustment circuit 85.

In this case, by connecting the connector 58 of the scope 52,
The scope discrimination signal is input from the scope discrimination circuit 113 to the RGB synchronizing circuit 112, and the R gain selection circuit 114R and the B gain selection circuit 114B respectively determine the R gain when the R signal is input, and the R gain control signal and the B signal when the B signal are input. Output to the RGB switching circuit 116, and the G gain setting circuit 115G also sets the gain when the G signal is input to 1
Is output to the RGB switching circuit 116.

The RGB switching circuit 116 changes the output signal of the R gain selection circuit 114R according to (the R switching signal of) the RGB switching signal shown in FIG. 8B when the R signal shown in FIG. 8A is input. Output. That is, the switches forming the RGB switching circuit 116 are switched, the R gain control signal is applied to the gain setting switches S1 to S5 of the white balance adjustment circuit 85, and these switches S1 to S5 are turned on or off to set the white balance. The gain of the adjustment circuit 85 (R gain at the time of inputting the R signal) is set to 1/2, and FIG.
The R signal shown in FIG. 3C becomes the R signal shown in FIG. Next, when the G signal is input,
The RGB switching circuit switches the switch so that the gain control signal of the G gain setting circuit 115G is output. Therefore, the G signal in FIG. 8A is output with a gain of “1”. The R signal is adjusted to have an output level equal to the output level of the G signal.

Similarly, when the B signal is input, the white balance adjustment circuit 85 at the time of the B signal input sets, for example, the B gain to “2”, and outputs the B signal output from the white balance adjustment circuit 85 as the R signal. It becomes equal to the output level of the G signal.

In this way, as shown in FIG.
With respect to the B signal, the gain is set to an appropriate level by a synchronous switching signal shown in FIG. 7B, and the R, G, and B signals are output in a white balanced state.

According to the first embodiment configured as described above, different types of CCDs in the electronic scope and different spectral characteristics are used, and light transmission characteristics such as the length of the light guide and the material of the light guide are used. Even if there is wavelength dependence, the connector 58 of the scope 52 is opened or grounded with a plurality of pins P1 to P6 of the discriminating connector 103 as a means for discriminating information on comprehensive spectral characteristics for the electronic scope. Certain information on the spectral characteristics is displayed (by encoding, etc.). Therefore, the outer shape of the electronic scope 52 can be merely different from that of a normal one in a part of the connector. For this reason, the cost of manufacturing this electronic scope hardly changes. In use, the electronic scope itself does not increase in weight or size, so that operability can be prevented from lowering. Further, the present invention can be used for a commercially available electronic scope having no discrimination connector as before. In this case, the white balance adjustment circuit 85 may be set to the manual operation mode, and the switches S1 to S5 may be manually turned on and off.

According to the first embodiment, since the color signal whose white balance has been adjusted according to the total spectral characteristics of the connected electronic scope is output, even if the electronic scope is not adjusted,
It can faithfully reproduce the image of the subject in color.

FIG. 9 shows a connector 121 of an electronic scope according to a second embodiment of the present invention.

This connector 121 is an existing connector 122 having no discrimination connector 103 (the light source connector 101 and the signal connector
102), an adapter 123 provided with a discriminating connector 103 can be detachably fixed with a screw 124. In this case, an adapter 123 having pins P1 to P6 set to ground or open corresponding to the electronic scope having the connector 122 may be attached.

 Others are the same as the first embodiment.

According to this embodiment, even in the case of an electronic scope having no discrimination connector 103, the white balance can be adjusted by using the signal processing device 53 having the scope discrimination circuit 111.

FIG. 10 shows a white balance adjustment circuit 131 according to a third embodiment of the present invention.

In this embodiment, the RGB signal is input to a gain control amplifier (hereinafter abbreviated as GCA) 132. This GC
The A132 gain control terminal has an RGB synchronization circuit 112
Is converted into an analog signal by the D / A converter 133 and applied. The gain of the GCA 132 is variably controlled by an analog gain control signal applied to the gain control terminal, and white balance can be adjusted in the same manner as in the first embodiment.

FIG. 11 shows scope determining means in the fourth embodiment of the present invention.

In this embodiment, for example, a resistor Ra corresponding to a scope is connected between one pin 141 of the signal connector 102 and the ground pin 142, while a corresponding resistor Ra in the signal connector receiver 105 of the signal processing device 53 is connected. The pin receiver 141 'is connected to the output terminal of the constant current circuit 143, and the A / D converter 14
The digital data corresponding to the resistance Ra is obtained via 4. The pin receiver 142 'of the ground pin 142
Is grounded. If, for example, 5-bit output data of the A / D converter 144 is input to the RGB synchronizing circuit 112, the same operation as in the first embodiment is performed.

 FIG. 12 shows a fifth embodiment of the present invention.

In the electronic endoscope device 51 'of this embodiment, an electronic scope
52 'is designed to cope with the case where the CCD 68' having a different number of pixels is used.

For example, the connector 58 'of the electronic scope 52' is provided with a discriminating connector as in the first embodiment, and the discriminating connector further includes a pin (not shown) indicating the type of the number of pixels of the CCD 68 '. However, for example, in FIG.
What is necessary is just to increase the number of P6. ) Is provided, and the scope discriminating circuit 111 'of the signal processing device 53' is further provided with a comparator (not shown, for example, if the number of comparators C1 to C5 is increased in FIG. good.)
Is provided.

A discrimination signal relating to, for example, a spectral characteristic (FIG. 1) in the discrimination signal of the scope discrimination circuit 111 'is input to the RGB synchronizing circuit 112', and the (second) discrimination signal of the number of pixels of the CCD 68 'in the discrimination signal is , A driver 78 ', a clamp pulse / sampling pulse generation circuit 151, a low-pass filter 84', three low-pass filters 91 ', a memory control circuit 93', and three horizontal contour correction circuits 152. .

The above clamp pulse / sampling pulse generation circuit 15
The one clamp pulse and the sampling pulse are input to the double sampling circuit 83 ', and output a signal from which reset noise has been removed. (The above reset noise removal circuit
One of 83 circuits. According to the pixel number discrimination signal from the scope discriminating circuit 111 ', the driver 78' outputs a drive signal having a clock frequency and a clock number corresponding to the pixel number of the CCD 68 '.
Apply to 8 '. From the signal read from the CCD 68 ', only the signal component of this signal is sampled and extracted by the double sampling circuit 83', and only the signal band corresponding to the number of pixels is passed by the low-pass filter 84 '. The A / D conversion rate of the A / D converter 87 'is controlled by the memory control circuit 93', and the memories 88R ', 88G', 88B '
The writing and reading clock frequencies are also controlled. Further, the D / A conversion rate of each D / A converter 89 'is also controlled.

The contour correction of each horizontal contour correction circuit 152 is also changed according to the number of pixels.

Each of the low-pass filters 84 'and 91' is composed of a low-pass filter that can set a plurality of cutoff frequencies according to the number of pixels. These low-pass filters 84 ', 9
1 'or the memory control circuit 93' and the memories 88R ', 88G', 8
8B 'and the horizontal contour correction circuit 152 are disclosed, for example, in Japanese Patent Application No. 62-1.
It can be composed of those described in 7982.

According to the fifth embodiment, white balance can be adjusted even in the case of an electronic scope having a different number of pixels.

Note that the present invention is not limited to an electronic scope in which a solid-state imaging device such as a CCD68 is housed at the distal end side of the insertion portion, but also a fiber scope in which an image guide is formed by a fiber bundle or an optical type in which an image guide is formed by a relay optical system. The present invention is also applicable to an endoscope apparatus in which a television camera containing a CCD is mounted on an eyepiece of the endoscope.

It should be noted that a signal of information for white balance adjustment may be output instead of information on spectral characteristics and the like provided on the electronic scope side.

[Effects of the Invention] As described above, according to the present invention, the electronic scope side is provided with means for generating information relating to the overall spectral characteristics of the electronic scope or white balance adjustment information, while the signal processing apparatus side is provided. A means for determining or decoding the information of the generating means and performing a white balance adjustment suitable for the electronic scope is provided. Can be reproduced in color.

[Brief description of the drawings]

1 to 8 relate to a first embodiment of the present invention.
FIG. 2 is a configuration diagram of the electronic endoscope apparatus of the first embodiment, FIG. 2 is a schematic side view of the first embodiment, FIG. 3 is a perspective view showing a connector and a connector receiver, and FIG. FIG. 5 is a circuit diagram showing a transmission characteristic of a light guide, FIG. 6 is a block diagram showing a configuration of an RGB synchronization circuit, FIG. 7 is a circuit diagram showing a specific example of a white balance adjustment circuit, and FIG. FIG. 9 is a timing chart for explaining the operation of the white balance adjusting circuit, FIG. 9 is a perspective view showing a connector according to the second embodiment of the present invention, and FIG. 10 is a diagram of the white balance adjusting circuit according to the third embodiment of the present invention. FIG. 11 is a block diagram showing the configuration of the periphery of the scope discriminating means in the fourth embodiment of the present invention, FIG. 12 is a block diagram showing the configuration of the fifth embodiment of the present invention, and FIG. Description showing a rotating filter for white balance FIG. 14 is a waveform diagram for explaining the operation of FIG. 13, FIG. 15 is a waveform diagram for explaining the operation in the conventional example of the pulse light emission system, FIG. 16 is a configuration diagram showing a conventional example of an electronic endoscope device, FIG. 17 is a circuit diagram showing a white balance adjusting circuit used in FIG. 16, and FIG. 18 is a waveform diagram for explaining the operation of FIG. 51: electronic endoscope device, 52: electronic endoscope 53: signal processing device, 54: color monitor 57: universal code 58: connector, 62: connector receiver 85: white balance adjustment circuit 103… Discriminating connector 106… Discriminating connector receiver 111… Scope discriminating circuit 112… RGB synchronizing circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahide Sugano 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside O-Limpus Optical Industrial Co., Ltd. (72) Inventor Shinji Yamashita 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside the Olympus Optical Co., Ltd. (72) Masahiko Sasaki, inventor 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside the Olympus Optical Co., Ltd. (72) Katsuyoshi Sasakawa 2-43-2, Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (56) References JP-A-61-179129 (JP, A) JP-A-61-2120 (JP, A) JP-A-64-17621 (JP, A)

Claims (1)

(57) [Claims] An electronic endoscope comprising: an electronic endoscope using a solid-state image pickup device for imaging a color image of a subject as an imaging means; and a signal processing device connected to the electronic endoscope and containing signal processing means. In the endoscope apparatus, a different pin connection is made for each overall spectral characteristic of the electronic endoscope, a connector for connecting the electronic endoscope and a signal processing device, and the connector provided in the signal processing device, Determining means for detecting a state of the pin connection and outputting a white balance adjustment signal; and white balance adjusting means for obtaining a white balance for the captured color image by the white balance adjustment signal output from the determination means. An electronic endoscope device comprising: