JPS5895717A - Automatic exposing device of endoscope photographing system - Google Patents

Abstract

PURPOSE:To obtain correct exposure even at the time of near range photograhing, by calculating the exposure before photographing from the illuminating light quantity, the reflected light quantity and the set photographing condition, discriminating a result of said calculation, and deciding whether a flash can be generated or not. CONSTITUTION:From the illuminating light quantity LSEND and the reflected light quantity LRCV, the exposure light quantity S is calculated as S=(K/ ASA)X(LSEND/LRCV), and is decided in comparison with the flash total light quantity Lt stored in the pre-processing stage. In case when the exposure light quantity S is larger than the total light quantity Lt, or is smaller than the lower limit light quantity of observation light automatic exposure Lt/40, incorrect exposure is displayed, and in case when said quantity is between the lower limit light quantity Lt/40 and the lowest automatic exposure light quantity Lt/10 (at the time of near-by photographing), generation of a flash ''FLASH'' signal is inhibited, and automatic exposure photographing by observation light is designated. In other case, correct exposure display is executed, and flash photographing is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic exposure device, and particularly to an automatic side suspension device used in an endoscopic photographing system.

When taking automatic exposure photographs of the inside of a body cavity using the family celebration fM photography system, there is a limit to which automatic exposure control cannot be performed for flash light as the photographing light in close-range photography.If the photograph is taken at a close-range that exceeds this limit, the photograph may be overexposed. It becomes.

As a means for preventing overexposure in such short-distance photography, Japanese Patent Laid-Open No. 52-10127 discloses that a pattern is inserted into the photographing light source when it is determined that the automatic exposure limit has been reached. However, the interior mirror is a trap that illuminates the subject through a light guide for observation and photography. For this reason, if a pattern is provided between the light source and the light guide, the angle at which the shooting light enters the light guide will change, which will change the illumination angle of the subject and worsen the light distribution of the illumination light to the subject. . If the light distribution in the body cavity becomes poor, the quality of the photographic image will be poor, and accurate diagnosis will not be possible. are not clearly imaged, making accurate diagnosis difficult. Also, in Japanese Patent Application Laid-Open No. 55-147619, N
A means of adjusting automatic exposure using a D filter has been disclosed, but since such a method does not control in real time, when a moving subject is photographed with sidelight, the exposure value may be different, resulting in a properly exposed photograph. There is a problem with this.

Therefore, it is an object of the present invention to provide an automatic exposure kfjjL for an endoscope photographing system that can obtain 4 proper exposure photographs in close-range photography that exceeds the automatic exposure limit using photographing light.

Embodiments of the present invention will be explained below with reference to the drawings. Swimming 1
According to the figure, endoscopic fip, 1, light source uni.

The camera 2 and the endoscopic camera 3 constitute an endoscopic photographing system. The endoscope 1 is provided with an image guide 5 and a light guide 6, and a subject 4 is illuminated by light guided through the light guide 6. An objective lens 1 is provided at the front end of the image guide 5, and an oscillating lens 8 is provided at the rear end. A camera 3 is attached to the eyepiece 9, and the camera 3
The beam splitter 110 faces the eyepiece 1. A filter 5 11 is disposed opposite to a beam currant 10 via a mirror shank 12. Camera control circuit 13
is the light receiving element 1 provided on the side of the beam currant 10.
The ISO signal end of the camera control circuit, which is connected to the switch JJj and the release switch JJj, is connected to the connection bin 1#.

Xenon (X・) discharge lamp P1# for light source unit and unit 2
The connector part 20 is connected to the light source unit so that the light guide end 19 is located on the optical axis of the lamp 18.
connected to port 2. Connector part 2- connection vinyl/211
d Light source control via the socket of
Connected to JF. The X discharge land 18 is composed of a cathode j1 and an anode 2J facing each other, and a reflecting surface J4. A condenser lens, an exs, a shutter blade J#, and a crest blade 21 are sequentially arranged between the X-discharge lamp 11 and the light guide end 19. The blades are driven by a solenoid IRK, and the blades are driven by a zeIIi motor. Light guide end 1
A light guiding member 31 made of, for example, an acrylic rod is disposed between the crest blade 9 and the crest blade 18. This light guide member JJ
There is a slope on the O-Shipsha lamp 18 side, and the light receiving element 1 is on the rear end.
2 is arranged. In FIG. 2, the shutter blade 3g, the crest blade 28, and the light guiding member 1 are shown in perspective.

FIG. 3 shows the circuit configuration of the camera control circuit IJ. According to this circuit, the light receiving element 14 is connected to an operational amplifier 36 of an integrator/current/voltage converter 37. Integral capacitor S4 between operational amplifier 360 inverting input terminal and output terminal
and a current-voltage conversion resistor 36 are connected in series. Short-circuiting analog switches 3a and 39 are connected to the integrating capacitor 38 and the resistor 35, respectively. The output terminal of the integrator/current-voltage converter 31 is connected to the output terminal of the rendegrator 40 (amplifier 4
It is connected to the non-inverting input terminal of 1. The inverting input terminal of the operational amplifier f42 is connected via the D/A converter 42 to
Connected to UjJ. The output terminal of the operational amplifier 7#41 is connected via the analog switch 44 to the non-inverting input terminal of the operational amplifier 41 of the buffer 1 circuit 4S. Also, the non-inverting input terminal of this operational amplifier 41 is connected to the output terminal of the operational amplifier f36 via an analog pda switch 46, and the analog switches 44 and 45 are opened and closed by the output signal of the CPU IJ. is controlled by a signal via Invar/Dart 4#. The inverting input terminal of the operational amplifier 410 is grounded via a resistor 48 and connected to the output terminal via a resistor 4#.

The output end of this P/F circuit 43 is connected to the terminal.
Terminal f is grounded, and terminals a and b are connected to Van and GND, respectively. Terminals e and d are connected to the CPUJJK via a serial interface 50. CPU
J3 is inverter 51, light emitting diode (LED)
Vec[ is connected via Sj and resistor 53.

FIG. 4 shows the circuit configuration of the light source control circuit 110 of the light sources 22 and 2. In this circuit, terminals e and d
is connected to serial interface 54. CPU 5 via serial interface x14Fit4x
B, ROM 5 e, TEAMJ single person converter 5
8. Connected to D/A controller 59, condition setting display 22, trolley 0 and DARL interface 61.

The terminal ・ is connected to the non-inverting input terminals of the low-amplification amplifier circuit 62 and the high-amplification amplifier circuit 63 (An 7664 and e7). and is connected to the output terminal via a feedback resistor 6C. Similarly, resistors 68 and 69 are connected to the inverting input terminal of the operational amplifier 610. The output end of the yin Δlator 10 is connected to the parallel 1/)'61'
CHAR (connected to the terminal J'. The non-inverting input terminal of the operational amplifier 12 of the 4-tension amplifier circuit 11 is
A resistor rs is connected to the tension meter 30 and is connected to the inverting input terminal.
and 14 are connected. The current-voltage converter 15 to which the light-receiving element S2 is connected is an operational amplifier! 16 and a resistor 11. The output terminal of the V converter j9 is connected to the inverting input terminal of the operational amplifier 7''Fjl of the pattern driver 1a, and is also connected to the output terminal of the transistor 82 and the pattern motor 29 via the resistor IO. The cap is connected to VsK through a resistor 81, and the terminal is connected to the output terminal of the operational amplifier 19.

FIG. 5 shows the power circuit for light source 22 and light source 2. The X discharge rung 18 is connected to a high voltage generation source consisting of a high voltage generation circuit 81 and a high voltage generation coil 84. This high voltage generation source is connected to a rectifier circuit 89 via an X-Lang current control section that is composed of an X-Lang current control circuit 85, a current detection resistor 8C, and a current control transistor 81, and a check coil 90. Ru. The power terminal of this rectifier circuit i88# is connected to the secondary winding of transformer 88. The flash converter 9) is connected to the rectifier circuit 93 via resistor #2. The power terminal of U-wave circuit #3 is the second winding l[! of transformer 940]. & continued. The primary winding of the transformer 94 is connected to the AC'%L source line via a trier 95. The trier is connected to a capacitor/capacitor charging pressure control circuit 96 that generates an ll1l control signal according to the charging voltage of the #5 capacitor 910.

One end of the capacitor 91 is connected to a transistor 97 and a transistor drive circuit 98 . The elector of the transistor 97 is connected to the cathode of the X-lamp 11, and the pace is connected to the drive circuit. The source circuit 9 is connected to the AC line #/c via a transformer 100.

In the above-mentioned circuit, the converter 58 has a built-in multiplexer, and can output digital outputs of 98, 0ADCO808 and 98.
is used. This ADC0808 has 8 channels of analog input at 8 pins.

In the embodiment, four channels of analog inputs A to As are used. These inputs A
-A3 are connected to the amplifier circuits 62, 63, rl and the output of the current-voltage converter 75. If the CPU 5g uses Intel's 8085, the serial interface 54 uses an 8251A of Intel's 8085 family, and is connected to the camera 3 as a UART. ROM5#F
The one that corresponds to the i program capacity is used, and if the capacity is 2 to 2 bytes, 2716, which is 7 mm, is used. In addition, 57 pieces of RAM and 2114 pieces of RAM are used.

The D/A converter 59 is used to convert 8-bit digital data into analog output.
Company 0DA01008 is used. This has the advantage of being directly connected to the CPUSS data bus. Note that since the analog output of the D/A converter 59 is a current output, it is converted into a voltage by the pattern driver ra. In addition, the N-converter 58 has a resolution of 8 bits, which is substantially 16 bits, and 6 bits.
1 condition to be used, setting/display 22, Toro 0 is shooting still film sensitivity, cine (TV) y illuminance sensitivity, still-cinema correction during auto shooting, still auto-manual switching, cine auto - Manual switching, cine manual, ie manual light intensity setting is possible. Nonaka Urel Inter 7 Ace 61
Uses 7Amilii 8255A manufactured by Inch.

Next, the above-mentioned nine internal vision fi! The operation of the imaging system will be explained. When the power supply circuits of light sources 22 and 2 (Fig. 5) are turned on, the X-run f1af4 range lights up, and the light source signal processing circuit (Fig. 4) after the light source starts its initial operation, and the light source signal processing circuit (Fig. 70
- Preprocessing for pre-shooting exposure calculation is performed according to the chart.

In other words, when the AS system sensitivity etc. are set in condition setting/display 22, trol 0, only the setting data is output and stored in the RAM S.
Stored in F. 9 capacitors (5th
If @CHAR(J"UPL, the 0 determination made by the figure) is @YES', the multiplexer of the ψ converter 58 is set to M. At this time, the "FLASH" signal is sent from the parallel interface 7Ace 6). is output. In response to this FLA8)1" signal, the transistor ! of FIG.
The drive circuit 98 turns on the transistor 91 and causes the X@2 ring 18 to flash. At this time, Sha.

! The blades 16 and the crest blades 18 are open], and part of the flash light is guided to the light receiving element 32 by the light guiding member J1. The light receiving element J2 detects the flash light as photographing light. The output of the light-receiving element 31 is converted into a voltage signal by a current-voltage converter 75 and inputted to a terminal -As of the converter 51. The converter 58, which is the A/D converter 11, receives the light reception data of the light receiving element J2 and stores it in the RAM 5F.The 0 judgment is @YEI.
I' is 44 larel imme-7 ace 61 @
51TOP” signal can be output.

In response to this “!ITOP” signal, transistor #r
becomes OFr, and the flashing of the X lamp 18 stops and becomes normal light emission. 4/I) RAM taken into converter 58
5 PK The stored light reception data is integrated and the total flash light j
RAM s r as ifliL-t (lux seconds)
is stored in

After the pre-processing of the pre-photographing exposure calculation is performed, endoscopic observation and endoscopic photographing are performed.

When performing endoscopic photography, the camera 3 is attached to the eyepiece 9 of the endoscope fIJ. At this time, the light receiving element 14 of the camera 3 receives reflected light from the subject via the image guide 5, the eyepiece lens 1, and the beam currant 10. At this time, if the serial interface J4 detects that the camera 3 is connected to the endoscope IK, the pre-shooting exposure calculation
2+6, that is, t
The multiplexer of the f-channel converter J8 is set to the mu-channel, and the photometric data corresponding to the light receiving element 32 is taken into the converter laK. This photometry day/Fi is data corresponding to the illumination light, and is stored in RAM as Ltendi.
Stored in SF. The multiplexer of the A/D converter is set to A@ or AI and receives reflected light data corresponding to the object reflected light from the power camera 3.

The data of the converter 58 is stored in the RAM 57 as reflected light JiLr.The zero-order light amount B is calculated based on the following equation.

K: Lax or Lux of the detected value of the illumination light of the subject, the detected value of the reflected light of the subject, and the detected value of shooting light 1ii (2)
・Includes the converted value of 8.C.

ASA: Film sensitivity L-! The required light amount (Lux-1@e) on the film surface is determined by the amount of incident light on the 1d light guide, which includes the coefficient for converting this into illumination light and the loss coefficient of the light guide, image guide, etc. .

The no light amount S obtained by the above calculation is the flash total light amount L-
It is determined whether t is greater than t. If this determination is "YE8", inappropriate exposure can be displayed. If the determination is "No", it is determined whether or not a 0 determination is made in which an appropriate exposure display is made even if the no-light amount S is "NO". ζゐjudgment is “YES”
” then incorrect exposure will be displayed, @NO# then @F
This indicates the minimum automatic exposure light amount when the LASH ring 18 flashes, the normal lighting light of L@t Fix/run fxs, that is, the minimum automatic exposure light T1 of the observation light, that is, the observation light automatic exposure lower limit light amount. The determination determines whether the measured light amount S is within the light amount range from the shooting light automatic exposure lower limit light amount to the observation light automatically calculated light amount.Sb Within this light amount range, no photographing light is generated and only observation light is generated. , automatic exposure shooting will be displayed. In addition, appropriate and inappropriate exposure will be displayed in the shooting condition setting display unit and Toro 0, and @FLASH
“Information F! of prohibition of signal generation is stored in the ILAM 51.

After the pre-photographing exposure calculation is performed as described above, the photographing operation begins next.

If it is determined in the pre-photographing calculation that the photographing can be performed properly, the photographing operation is performed according to the time chart shown in FIG.

Immediately, when the release switch 15 is closed at T1, the light source shield 28 begins to open, and the signal at the camera contact point f becomes low level, and the light source shutter 2# begins to close, and the light guide end The incident light to 1# is continuous, and the output of the integrator/current-voltage converter 31 becomes 0 value. After a predetermined time T2, the second shutter 12 of the camera 3 opens, and the light source shutter 26 opens. When opened, light enters the light guide end 19, and the output of the integrator and current-voltage converter 3r operates as an integrator.
Integrate the received light signal corresponding to the reflected light from the object. The X-lamp 18 flashes at 3 when the light source shutter 26 is fully opened. When the calculated exposure value reaches the appropriate exposure value, a "5TOP" signal is generated, and the light emission of the X lamp 18 is stopped at T4.
At a predetermined time interval T5, the shutter 12 closes and the release switch 15 opens, completing the photographing. After this,
- Run f1B is normally lit and returns to the observation state. In addition, V r@f in the exposure calculation is
Since it is determined by the settings and the light source is also set to the same A8A, it is possible to calculate the exposure before shooting.

The operation of the dangerous automatic exposure photographing operation based on the photographing light from the flash of the X-run fxs will be described with reference to the time chart of FIG. 8. In this case, the mirror shutter 12 of camera 3 begins to open at T2, and when the mirror shutter 12 fully opens at T3, the @FLASH' signal is not generated, so the
The lamp 18 is normally lit without flashing, that is, the observation light is incident on the light guide end 19. 11! Light is detected via a light guide 6, and reflected light from a nearby subject 4 is incident on the camera 3 via an image guide 5, and then the film 11 in the camera s is detected.
The light is exposed and converted into a light reception signal by the light receiving element 14.The light reception signal is integrated by the integrator and current voltage converter sr, but due to close-up photography, even observation light causes a large amount of reflected light to enter the camera 3. Is the integration time short? (At T4, the integrated voltage becomes the reference voltage Vrvf. At T4, -5T
OP'' signal is generated. CPU 51 is @8TOP
In response to the signal -g) IATTERCLO8E, a signal is generated to close the shutter 26. Thereafter, at 5, the shutter !12 is closed, the release switch 15 is opened, and close-up photography is completed.

In this way, automatic exposure photography is carried out using the observation light from the low-light lid as the photography light without generating photography light in close-up photography, so even in close-up photography you can obtain properly exposed photos without overloading with lightning. .

Next, another embodiment will be described with reference to FIG. In this embodiment, the light receiving element 32 is arranged so as to detect the observation light and the photographing light near the X-rung 1g (D). The appearance time t is calculated using the following equation (2) with a button symbol.

L: Light reception signal corresponding to the reflected light of the subject S: Amount of pattern embossed F: Fra, shank h (flash light) Magnification 10 < t < 100 (3) 1, <”°(
4) 10 (tNB (250 tF: Exposure time with flash tNF: Exposure time without flash) The automatic exposure range with flash is determined by formula (3), and the automatic exposure range without flash is determined with formula (4) Then, formula (4)
In the case of , the flash magnification is not calculated, and in the case of non-flash, Kt
Although the exposure time is 10 m11@·, automatic exposure is possible at the maximum exposure time of the camera 3, that is, 250 m·ei. t); If the exposure light of -10m5e* is smaller than the exposure amount when tNF=250ms*e, it means that the photographing range H has been continuously expanded. Incidentally, the flash magnification F can be calculated from the light reception signal corresponding to the observation light and the light reception signal corresponding to the flash light. In the case of non-flash, formula (2)
It is sufficient to calculate t without the term below, and in this case, the exposure range can be found as shown in equation (4)K.

As explained above, according to this invention, during close-range photography, the light source is not flashed, and the close-range subject is photographed and illuminated using normal lighting, so there is no possibility of overexposure at close range, which will worsen the light distribution of the illumination. is prevented. In addition, since exposure calculation is performed in real time even in close-range shooting, it is possible to take a photograph at an appropriate distance of 11 meters, even for a moving subject.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an endoscopic photographing system using an automatic exposure device according to an embodiment of the present invention, FIG. 2 is a perspective view of a shading mechanism and a shutter mechanism, and FIG. The circuit configuration diagram of the camera, Figures W and 4 are circuit diagrams of the signal processing circuit of the light source 22 and G, Figure 5 is a circuit diagram of the power supply circuit, and Figure 6 is a flowchart explaining the preprocessing tube for calculating exposure before shooting. , FIG. 7 is a flow chart diagram explaining the operation of pre-shooting exposure calculation, 11g8
The figure is a time chart diagram explaining the photographing operation for automatic exposure photographing using the photographing light, FIG. 9 is a rhythm diagram explaining the automatic exposure photographing operation using the observation light, and FIG. 1 is a schematic configuration diagram of an endoscopic photographing system using an automatic exposure device. 1... Endoscope, 2... Light source unit, 3... Camera, 5... Image guide, 6... Light guide,
The axis/eyepiece section, 12...mirrorsha, ri, 13...
Camera control circuit, 14... Light receiving element, 15... Release switch, 11... Light source control circuit, 18...X
・Discharge lamp, 19...Light guide end, 31...
Light guide member, Jj-・light receiving element, jj・CPU, 5
5-CPU. Applicant's Representative Patent Attorney Takehiko Suzue Figure 3 Figure 4 Procedural Amendment Form 5c1. I80 Haruki Shimada, Commissioner of the Patent Office 1, Indication of Case Patent Application No. 193800, Showa E6-193800, No. 2 Name of Invention Automatic Endoscopic Photography System! ! Relationship between the issuer 3 and the amended case Patent applicant (037) Orin ES Optical Industry Co., Ltd. 4, agent. Ya57. !・27B Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Case Indication Special - No. 1980-193800 2 Name of the invention Automatic exposure device 3 for an endoscopic imaging system, relationship with the Nagisa case with supplementary IE Patent applicant (037) Olympus Optical Industry Co., Ltd. 4, Agent 6, Specification subject to amendment, Drawing 7, Contents of amendment (The scope of claims in the attached specification of Book 11 II is amended as shown in the attached sheet. (21 Ibid., page 2 of I86) From line 3 to “Kiya/mother 38”
The statement has been corrected to read "Kano arm 34". (In the 7th line of page 6 of the 31 same page, [Operational amplifier 42J is corrected to ``Operative amplifier 41.''
Connected to the "CIIARGE" I terminal of 1 - is connected to the parallel 17F g 1. ” he corrected. (5) On the 11th line of page 189, the phrase [TRIAC 95 key/# letter] is corrected to "TRIAC 95 is key/l letter." (6) On page 1149, line 16, ``Erector J is corrected to ``Collector.'' (7) On page 18, line 19, after “Connected.” “From the capacitor charging voltage control circuit 96 to the capacitor 4V 91
"CHARGE" signal B that @CHARGE"UP
, V le I/F 61 (D''” CHARGE
"FLA8H"", "5TOP"I signals input to the transistor drive circuit 98 are input from the parallel I/F 6J. ” to join. (8) On page 10, line 144, "analog input" is corrected to "analog input and". (9) Page 14, line 17.10.166 rL rev
Correct "J" to "L rcv J." r 5HATTER on line 1419, page 18, 1]
CLO8E J and the r 8HUTTERcLos
g Correct it as J. Oυ same page 20! At the 149th mark, the phrase "flash magnification lower" is corrected to "flash magnification F." (2) The correction code "91" in Drawing In2 of the drawing attached to the application is corrected to "96J" as shown in the attached sheet.2. Scope of Claims 1) A first device for detecting observation light and photographing light illuminating the subject.
a light-receiving element, a second light-receiving element for detecting reflected light from the subject, a photographing condition setting means for setting photographing conditions; l! ?
] Pre-photographing exposure calculation means for calculating pre-photographing exposure from the observation jtt and photographing light quantity detected by the first light-receiving element, the reflected light quantity detected by the second light-receiving element, and the photographing conditions of the first photographing condition setting means. and means for determining whether the exposure calculation result by the pre-photographing exposure calculation means is within a predetermined automatic exposure light amount range; An automatic exposure device for an endoscope photographing system comprising means for performing automatic exposure photography using the observation light. 2) The automatic exposure light amount range is from a shooting light automatic exposure lower limit light amount to an observation light automatic exposure lower limit light amount. An automatic exposure device for an endoscopic photographing system according to claim 1. 3) The observation light (iii) is obtained by normal light emission of the light source, and the first photography light is obtained by flashing the light source (4), and the observation light automatic exposure photographing means prohibits the light source from flashing. Non-patented claims with means $1
An automatic exposure device for an endoscopic imaging system according to item 1 or 2.

Claims (1)

[Claims] 1) A first device for detecting observation light and photographing light illuminating the subject.
a light-receiving element, a second light-receiving element for detecting reflected light from the subject, a photographing condition setting means for setting photographing conditions, and a photographing condition setting means for detecting the amount of observation light and photographing light detected by the first light-receiving element; 2. A pre-photographing exposure calculating means for calculating a pre-photographing exposure from the amount of reflected light detected by the light receiving element and the photographing condition setting means, and a pre-photographing exposure calculation means that calculates the exposure calculation result by the pre-photographing exposure calculating means within a predetermined automatic exposure light amount range. and a means for prohibiting the generation of the photographing light in response to the within-range determination by the determining means and allowing automatic/dynamic exposure photography using the observation light. Vision f#, automatic exposure device of the photographing system. 2) The automatic exposure device for an endoscope photographing system according to claim 1, wherein the automatic exposure light amount range is from the photographing light automatic exposure lower limit light I to the fatigue light automatic koji brewing lower limit light amount. 3) The observation light is obtained by normal light emission from the light source O, the photographing light is obtained by internally illuminating the light source, and the observation light automatic exposure photographing means includes means for prohibiting the front light distribution source from flashing. Claim 1 or #'
i. An automatic exposure device for an endoscopic imaging system according to item 2.