Light source device for endoscope

[Detailed Description of the Invention]

[Field of the Invention] This invention relates to the light equipment for endoscopes, and the light equipment for endoscopes which has especially automatic and an exposure function.

[Description of the Prior Art] It passes, the endoscope photographing instrument is provided with automatic exposure control, and exposure calculation, i.e., EE calculation, is performed in this case by CPU provided in light equipment. This EE calculation is performed with a constant period, for example, the cycle of 100 a+sec,, based on the euphotic signal corresponding to Sighting light before photography, and proper exposure, overexposure, an exposure undershirt, etc. are displayed by that result. usually -- Endoscopy -- in order to make shutter speed as quick as possible in II truth photography, an iris diaphragm of light equipment is carried out to full open, but it passes, an iris diaphragm is controlled by endoscopic diagnosis automatically or in manual operation, and Sighting light is adjusted to desired brightness. For this reason, since it is influenced by the iris diaphragm value, the result of the exposure calculation before photography is calculated by converting into the value of an I11 shadow state. That is, exposure calculation is done so that it may be in the state in iris diaphragm full open and the amount size of lamp lights. For this reason, conversion magnification becomes very large when Restriction 9 value is small. moreover -- the euphotic signal level which extracts by manual Shooting, a value is set up small, and is obtained from a photo acceptance unit when distance with a photographic subject is large is very small, and such a signal is greatly influenced by the letter voice in a photo acceptance unit, a light measurement circuit, a preceding paragraph amplifier, etc., for example, a noise etc., -- a sake. For example, a euphotic signal may be buried in a noise. If exposure calculation is performed in the state of such a signal, even if there will be no reliability in a calculation result and a Russian status display will be made based on this calculation result, it is meaningless, and an operator is confused on the contrary, and photography is made to go wrong. As exposure calculation mentioned above, it is carried out to i Q Q 1sec and every, but doing exposure calculation without the meaning which brings an error result as mentioned above eventually makes the efficiency of work of CPU fall so much, and it is not preferred in computer control.

[Objects of the Invention] Therefore, the object of this invention is to provide the light equipment for endoscopes with which the exposure calculation result which does not carry out useless calculation processing and is reliable is obtained.

[outline Co According to this invention, the calculation circuit which performs the iris diaphragm and exposure calculation for adjusting the light volume of the illumination light which is provided in the front part of the light source which generates the illumination light sent into an endoscope, and this light source, and comes out of a light source is provided. An exposure calculation circuit does not do exposure calculation to EE data of an endoscope camera which carries out euphotic signal correspondence being below the cut-off point level corresponding to a noise level based on EE data, and underexposure is displayed.

[Example] In Drawing 1, the eye contacting part of endoscope 14 which has image guide 10 and light guide 12 is equipped with camera 16 for endoscopes, and a photograph of the image in the abdominal cavity is taken via an image guide. It is divided into two by optical beam splitter 18 which entered into camera 16, and one side goes into a film and another side goes into photo acceptance unit 22. Photo acceptance unit 22 carries out photoelectric conversion of the incidence light, makes it a voltage signal, and it inputs it into light measurement circuit 24. Light guide 12 of endoscope 14 is led to light equipment 26. The luminescence light of light source lamp 28 of light equipment 26 extracts, and is led to light guide 12 via 30 and shutter 32. Light source lamp 28, iris diaphragm 30, and shutter 32 are controlled by control circuit 34, and the output of light measurement circuit 24 is supplied to this control circuit 34. Kaisei (the route to light guide 12 from light source lamp 28 is intercepted), and when carrying out, shutter 32 leads the light of light source lamp 28 to photo acceptance unit 36, so that it may be indicated to Japanese Patent Application No. No. 130152 [ 58 to ]. This photo acceptance unit 36 changes incidence light into a voltage signal by photoelectric conversion like photo acceptance unit 22, and inputs it into light measurement circuit 38. The output of this light measurement circuit 3B is also inputted into control circuit 34. Indicator 39 is connected to this control circuit 34. According to the block circuit shown in Drawing 2 CPU40, ROM42, RAM44, variable frequency oscillator 46, programmable peripheral interface (PPI) 48, programmable in Turno deafness Le counter (PIG) 50, and I10 boat 52 of each other are connected via a pass line. Variable frequency oscillators 46 are To generate and To continuously about the pulse of predetermined frequency by control of CP LJ 46. The output of this variable frequency oscillator 46 is inputted into frequency / voltage (F/V) converter 56 via photocoupler 54, and is changed into a voltage signal. The output of F/V converter 56 is connected to the 1st outgoing end of comparison machine 58. The output of Measurement * optical circuit 24 of camera 16 is inputted into switch 62 via amplifier 60. Northeast Itchi 62 constitutes multiplexer 65 with switch 64, and either of switches 62.64 is closed by the control signal from PPI48 supplied via photocoupler 68. The output voltage signal of The potentio meter 66 which extracts to switch 64 and detects the iris diaphragm value of 30 is supplied. The signal through either of switches 62.64 is supplied to comparison machine 58. The output of this comparison machine 58 extracts via driver 67, and drives 30. The output of amplifier 60 and The potentio meter thetaB is led to switch 70.72, respectively. The output of light measurement circuit 38 is supplied to switch 76 via amplifier 74. Switch 70.72.76 constitutes multiplexer 77 and switching control is carried out by the l1lilll signal of P P I 4B supplied via photocoupler 78. Any one output of switch 70.12.76 is inputted into voltage / frequency (V/F) converter 80. V/F converter 80 answers the V/F conversion start signal from PPI48 through photocoupler 82, and outputs the pulse signal of the frequency according to input voltage. This pulse signal is inputted into negative logic clock input edge CLK of PIG5G via photocoupler 84, an inverter, and 8G. A gating signal is inputted into the gate end of PIG5G from PPI48. The output of I10 boat 52 is connected to indicator 39 via driver 88. Next, operation of the above-mentioned light equipment for endoscopes is explained. In this light equipment, a manual mode and auto mode can set up alternatively. Exposure check mode can be set up. At the time of a manual mode, switch 62 is turned OFF and switch 64 is turned ON. It is in this state, and it extracts by extracting, for example by a keyboard (not shown) and inputting a value, and data is inputted into variable frequency oscillator 46. This oscillator 46 generates the pulse signal of the frequency corresponding to iris diaphragm data. This pulse signal is inputted into F/V converter 56 via Foto Cabra 54, is changed into a voltage signal and inputted into comparison machine 58. On the other hand, the iris diaphragm data of The potentio meter 66 is inputted into comparison machine 58 via switch 64, and this comparison machine 58 inputs Output signal into * driver 61 at the difference of both iris diaphragm data. When extract driver 61 according to data difference, 30 is driven, the output of potentiometer 66 changes in connection with it and it is in agreement with input iris diaphragm data, Comparatively 30 is set as the value. Thereby, manual modulated light is carried out. At the time of auto mode, switch 62 is turned ON and switch 64 is turned OFF. The light measurement mouth of the iris diaphragm data and camera 16 which are determined by CP U 40 in this state, and EE data which was outputted from way 26, was amplified with amplifier 60, and passed switch 62 are inputted into comparison machine 58. Comparison machine 58 inputs the output signal corresponding to the difference of iris diaphragm data and EE data of camera 16 into driver 67. Driver 67 extracts according to data difference, 30 is driven, and, thereby, auto modulated light is performed. An exposure check is performed in check mode by the data in the circuit system of multiplexer 77. this exposure check -- the -- it explains based on the flow of 3A thru/orB [ 3 ] figure. It is confirmed whether the signal was received from camera 16 by 5TART. This is for a camera to confirm whether to be a type in which an exposure value display is possible. It confirms the AUTO key and whether to be immediately set to Auto exposure mode as it is YES. If it is in automatic exposure mode, switch 62 will be turned ON and switch 64 will be turned OFF. At this time, EE data from camera 16 is inputted into comparison machine 58, and a light source serves as automatic modulated light mode. Switch 70.76 is turned OFF in multiplexer 77, and switch 72 is turned ON. Therefore, the iris diaphragm data obtained in The potentio meter 66 is taken in, and a memory, i.e., the predetermined address of RA M 44, memorizes. Next, switch 10 is turned ON and switch 72 and 76 are turned OFF. At this time, EE data through amplifier po is taken in and it is a memory (the predetermined address of RAM44 memorizes.). In whether the main lamp is set to ON, a variable (it is set to JNDER and EE data is compared with the data of a sufficiently larger value than cut-off point data, i.e., a noise level, and an offset level as it is YES.) that it checks and is No, A variable is to U if EE data is smaller than cut-off point data! D It is set to ER and move to flow 20. EE is larger than cut-off point data, namely, Exposure weighing is calculated according to a following formula as a judgment is No. L=EEx255/IRl5xK. However, the ratio of valve opening of IRIS-To narrow down ii and a 255-/IRIS= iris diaphragm (255/255= iris diaphragm full open) 25510= -- fully closed and KO-overexposure system -- as for the conversion constant-FLS(20) x minimum Si t ivy time (201 sec) x minimum iris diaphragm value (1/20) and FLS, flash magnification, i.e., the flash luminescence light volume of 20 m5ec, expresses a number of times of Checking light intensity. It smells as a result of the above-mentioned calculation, and The L is set as 4 to which a variable expresses 0VER, when larger than 0VER value, for example, +1 and 5EV. +When smaller than 1 and 5EV, it is confirmed whether L is larger than Near-0VER=+0 and 5EV. 3 which expresses N-0VER that it is YES is set up. It shifts to flow 30 that it is NO. In this flow 30, under Exposure weighing 1 is calculated with a following formula. L-== (100) EEx255/IRl5xKuKLI-under system conversion constant-FLS X maximum flash time (100-m5ec) x maximum iris diaphragm value (1), ConnectionILltN-tJNDERJ: -- a person -- a large Keika judging is carried out, 2 which expresses OK that a judgment is YES is set up, and it judges that 1->UNDER=-1 and 5EV are NO. O which expresses LINDER that a judgment is No is set up, and 1 which expresses N-LJNDER (-- 0 and 5EV) that it is YES is set up. If variable O~4 is set up as mentioned above, it will be judged whether this variable is the same as last time. A variable is transmitted to camera 16 as it is YES. With a camera, a variable is judged in 0 * and 1.2.3, and if it is 0 and is a under display and 1, a Neya under display will be made. OK, i.e., exposure Appropriate, is displayed that a variable is 2. Neya over is displayed that a variable is 3, and an undershirt will be displayed if it is not 3. Next, the case of short-distance photography is described with reference to the flow chart of Drawing 4. In this short-distance photography, iris diaphragm value # at the time of photography is calculated so that shutter speed may be set to 201 sec from present iris diaphragm value # and EE level at the time of photography. As a fundamental formula for this calculation, it is shown below. r-EExFLS (20) x255-/IRISx 20 *5ecx x / 255 x-rX IRIs/EExFLS (20) X1/20r : (mVms) proper light exposure (±0EVt-100 (mVms)) EEL (mV) The present EE level FLS (T) : Flach magnification IRIS of TmS: Iris diaphragm value # in the present iris diaphragm value #X-short distance amendment If X is calculated based on the above-mentioned formula, this X is judged beyond in the minimum iris diaphragm value, and if it is No, the minimum iris diaphragm value will be set up and it will judge that the X <= maximum iris diaphragm value is the g and x>= minimum iris diaphragm value. The maximum iris diaphragm value is set up as it is No. Also in short-distance photography, a photograph can be taken by a proper light exposure by determining an iris diaphragm of short-distance photography as mentioned above. It carries out and is effect 51 of an invention!] Since it indicates by under [ exposure ] according to this invention without calculating a light exposure as EE data inputted from a camera is below a cut-off point level as explained above exposure control has reliability and always proper, since EE data buried in the noise is not used for exposure calculation and only an always positive calculation result is computed -- it passes and endoscopic photography is acquired.

[Brief Description of the Drawings]

Drawing 1 is a schematic structure figure of the endoscope system which used the light equipment for endoscopes of one example of this invention, Drawing 2 -- the [ the block circuit diagram of the principal part of the endoscope system of Drawing 1, and ] -- the [ 3 8 figure thru/or ] --B [ 3 ] figure -- inside [ of Drawing 2 ] ?j! The flow chart figure explaining Light source equipment for mirrors and Drawing 4 are figures showing the flow chart in amendment of short-distance photography. 14 ... endoscope, 16 ... camera for endoscopes, 22 ... photo acceptance unit 24 ... Light measurement circuit, 26 ... light equipment for endoscopes, 30 ... iris diaphragm 32...9 shutter, 36 ... photo acceptance unit, 38 ... light measurement circuit, 65.77 ... multiplexer, 66 ... The potentio meter 40 ... CPU, 42 ... ROM144 ... RAM. Fair copy of an applicant representative Jun Tsuboi drawing Patent attorney (with [ no change by the contents ]] figure 1) Drawing 4 Commissioner of JPO Mr. Manabu Shiga 1, display Japanese Patent Application No. No. 133801 [ 59 to ] of an incident 2, the title of an invention Light equipment for endoscopes Those who do 3 and amendment Related applicant-for-a-patent name (037) Olympus Optical 4 Co., Ltd. with an incident, a representative request (it is as the fair copy and attached sheet of the drawing attached to = beginning (with no contents C2 change) a written amendment) Showa A year 60. place, 24 days Commissioner of JPO Display of the Uga way part 1 and an incident Japanese Patent Application No. No. 133801 [ 59 to ] 2, the title of an invention Light equipment for endoscopes Those who do 3 and amendment Relation with an incident Applicant-for-a-patent (037) Olympus Optical 4 Co., Ltd., representative 1-26-5, Toranomon, Minato-ku, Tokyo 17th Mori Building 6, object specification of amendment j han The A, the contents of amendment (1) it is [ the 2nd page The detailed in the letter and ] in the 16th line with "writing" -- "-- correct with ". (2) Correct with "film 20" that it is in the 4th page of the 6th line thru/or the 7th line with a "film." (3) Correct that it is setting to 1 light equipment" on the 7th page of the 4th line, saying "set to an iris diaphragm of light equipment." . (4) Correct that it is in the 7th page of the 5th line thru/or the 6th line, saying "it is exposure check mode again", saying "when performing an automatic exposure in each mode, it is exposure check mode again." (5) Correct that it is on the 8th page of the 11th line in "check mode" in "exposure check mode." (6) It is as the 8th page of the 11th line thru/or the 9th page 2nd line Intoゝ "automatic exposure mode ... it becomes automatic modulated light mode." "the following things will be performed if it is in exposure check mode. That is, it corrects as ". (7) Correct that it is on the 9th page of the 7th line, saying "Switch 70 is turned ON and switch gamma2.gamma6 is turned OFF", saying "Switch 72.76 is turned OFF and switch 10 is turned ON." (8) said -- the 9th page [ 9th ] line -- r (it is with RAM44 " -- r (RAM44) -- " -- it corrects.) (9) said -- the 9th page [ 11th ] line -- "-- a under display and ... a display -- " -- if it is a rUNDER display and 1 about it being -- a N-UNDER display -- " -- correct. (10) It is lx =rxIRIS/EExFLS to the 12th page of the 1st line thru/or the 2nd line. It corrects that it is with (20) xl / 20J with rx=rx I RIs/[EExFLS (20) x1 / 20] J.