JPS59204028A - Electronic exposure control device - Google Patents

Abstract

PURPOSE:To simplify an exposure controlling circuit system, and also to execute exact exposure control by constituting so that an EE value is set by an illuminate-examining light, a measured data in the course of photographing is subtracted successively from the EE value immediately before release at the time of photographing, and the exposure is ended when the EE value is reduced to zero. CONSTITUTION:The photometric data of an A/D converter 14 is inputted to a CPU16 through an I/O port 15, and expressed in terms of an exposure value (EE value). In this case, an EV corrected value (EV level) and the level of an illuminate-examining light are inputted from a key unit (KEY) 22, and stored in an RAM18. An exposure constant is calculated by the EV corrected value read out of this RAM18. A distribution light quantity of both lamp light and stroboscopic light is considered in case of the operation of the EE value so that a photometric data of the lamp light corresponds to a photometric data of the stroboscopic light, and the obtained EE value is stored in an RAM17. Subsequently, the exposure time is calculated by the following expression, that is, the exposure time = the exposure constant X the illuminate-examining light level/the photometric data. To which part of a control range this exposure time is contained is checked, and overexposure, correct exposure or underexposure is decided. The result of the decision is inputted to a display panel 23 through a key panel controller 19, and whether photographing can be executed or not is decided by this display.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic exposure control device, and particularly to an electronic exposure control device used in an endoscopic imaging system.

In a conventional endoscopic imaging system, during collation, collation light is converted into a photoelectric signal by a photoelectric conversion element, and the amount of collation light is controlled by this photoelectric signal. During photographing, photographing light, that is, strobe light, is converted into a photoelectric signal, this photoelectric signal is integrated, and when the integrated value reaches a predetermined value, emission of the strobe light is stopped. In this way, conventionally exposure control has generally been performed in an analog manner.

Finally, recently, computer technology has been applied to endoscope devices, and endoscope devices have come to be controlled by a converter. Therefore, it has begun to be considered that exposure control is also controlled by a converter.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to relate to an electronic exposure control device that performs exposure control using combeater control.

The present invention will be described in detail below with reference to the drawings.

In FIG. 1, a light receiving element 1 is provided in a photographing device, for example an endoscope camera, and is connected to an amplifier circuit 12.

The output of the amplifier circuit 12 is A/D via the filter circuit 13.
The converter 14 is connected to the converter 14 . The output of the A/D converter 14 is connected to l10PORT 15.

The I10 port 15 connects to the CPUI via the data bus line.
6, ROM 17.

R, AM 18 and key panel controller 19. However, the CPU 16, ROM 17, and port 15 are connected via the address path line.
It is connected to the RAM 18 and the key panel controller 19.
JL'IIL control circuit (CTC) 20K connection saler. The cono CTC 2θ is connected to the illumination light level 21.

It is connected to the key/71° panel controller y19td, the key unit 22 and the display/P panel 23.

The operation of the electronic exposure control device will be explained with reference to the flowcharts of FIGS. 2 and 3.

First, I will explain the non-emotional time, that is, the heated time. In this case, the light-receiving element 11 outputs a photoelectric signal that is 1 [1,] different from the illumination light amount. The photoelectric signal is amplified by an amplifier circuit 12 and input to a filter circuit 13 . This filter circuit 1
3 shapes the waveform of the photoelectric signal so as to reduce conversion errors in A/D conversion by the A/D converter 14. A/D
Converter 14 outputs digital photometric data corresponding to the photoelectric signal. At this time, the photometric data is, for example, 1/10
Output can be output in units of 0 seconds. The photometric data from the A/D controller 14 is taken into the CPU 76 via the I10 port 15 and processed. Immediately) (KEY) 22 j
ll) The EV sleeve positive value (Ev level) and the level of the illumination light are input. These EV correction values and illumination light levels are RA
An exposure constant is calculated from the EV correction value stored in M1B and read out from this RAM18. To obtain this exposure constant, the exposure constant when Ev@positive value is O and the input EV correction value, for example, +1 or -1, are processed. The exposure constant, photometric data, and illumination light level are processed in the CPU 16 to obtain an EE value. In this case, the ratio between the illumination light amount, that is, the lamp light amount, and the photographing light amount, that is, the strobe light amount, is taken into consideration in calculating the EE value,
The correspondence relationship between the lamp light and the light of the light source 10 is determined. In other words, the distribution light morbidity r of both lights is taken into consideration in the KEE value calculation q- so that the photometric data of the lamp light corresponds to the photometric data of the strobe light. The obtained EE value is 11A:1417
is memorized.

Next, the exposure time is calculated using the following formula.

Check δ to see which part of the control range this exposure time falls on)lI:j. That is, overexposure, proper exposure, Oτ,
It is determined whether the output is insufficient or not.

Regarding the above exposure judgment, the exposure time that can be controlled is the shutter speed of the camera (constant: 250 m5ec)
The minimum exposure time is shorter (5 m (8)) than the Nutrobo dimming function J1. However, it is preferable that the exposure rI' be set within a range having photometric data, that is, A/D conversion data linearity, from the setting point of 1 length. FIG. 4 shows a graph showing the relationship between the distance p from the endoscope tip and A/D conversion data. In this graph, A/D conversion data within the range corresponding to the linearity curve is considered to be within the appropriate range, and A/D conversion data within this range is
The exposure time determined from the /D conversion data is determined as the appropriate exposure. The judgment result is displayed on the key panel controller 19.
When the information is input to the display panel 23 via the display panel 23, the information is displayed on the display panel 23. Based on this display, it is determined whether or not photography is possible. Incidentally, since the linear range of the A/D converted data changes depending on the low level and high level of the photoelectric signal, the gain control of the amplifier 12 is corrected according to the level of the photoelectric signal.

When the camera shutter is pressed while the EE value is being updated every 1/100 seconds as described above, photographing processing is performed according to the flowchart in FIG. 3. That is, the shutter of the light source is opened in response to the shirt release signal.

A timer is also set for the maximum photographing processing time. This maximum photographing processing time is set to the shutter speed of the endoscope camera, for example, 25-0 m5ec. When the strobe device emits light in this state, the light receiving element 11 outputs a photoelectric signal corresponding to the strobe reflected light. This photoelectric signal is transmitted to the amplifier circuit 1
2, filtered by the filter circuit 13, and input to the A/D converter 14. A/D
The A/D conversion data of the controller 14, that is, the photometric data is I 10.1? -1-, the photometric data is synchronized with the synchronized signal and is sent to the CPU in units of 2m5es, for example.
It will be sent to 16th. The CPU 16 subtracts photometric data in units of 2 m5ec from the latest EE value updated immediately before release. That is, as shown in FIG. 5, the A/D conversion data at time to-t+ is subtracted from the EE value. The subtraction result is kept as a new EE value J,'J-A
I'L. If this EE value is positive, a check is made to see if a synchro signal is being input, and if so, a check is made to see if the maximum photographing processing time, i.e. 250m5cC, has elapsed. This means that the A/D conversion data is read from the A/D converter mark 14, and the A/D conversion data corresponding to times 1 and -12 is read out from the A/D converter mark 14.
-Evening is subtracted.・Similar processing is performed and EE
When the value is no longer positive, a photographing process end command is issued. As a result, the light emission of, for example, a strobe device is stopped, and then the light source shutter and camera shutter are closed, and the photographing is completed.

In the data processing described above, when the EE value is positive but no synchronization signal is input, the photographing process ends. In such a situation, it is assumed that some kind of failure has occurred in the synchronization system, and photographing is stopped. Further, the photographing process is also terminated when 250 m5ec has elapsed. This is because when the shutter time of the camera exceeds the shutter speed, the shutter is closed and shut off, so data processing beyond this point is meaningless.

In the exposure calculation as described above, the exposure time is determined by the following formula, assuming that the reading time of A/D conversion data is 11.

In reality, since the maximum amount of light is output during photographing, it is corrected by the illumination light level when determining the exposure constant. υ1j Therefore, the following formula is obtained.

In the above-mentioned shadow processing, overexposure, proper exposure and O-exposure are displayed on the display panel 23. Further, -1 This display/gunnel 23 can display the collation light level and the EE value <a. 2, set by key 22,
3. The output of the illumination light source is controlled according to the level.・With the result "O", the illumination light control is released and 1.

As mentioned above, this invention allows the EE11I'i to be set from the oblique illumination light (k) and immediately before the release at the time of photographing.

σ)1! The measurement 1' date of the photographic part is successively subtracted from Louis 1〆1. ) is provided. Therefore, an analog circuit similar to the conventional l-type integrating circuit can be used as i″l l[: :! i'l
The exposure control circuit system can be simplified to 1F'+I without the need to use it for #, and moreover, accurate exposure control can be performed.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of an electronic exposure control device according to an embodiment of the present invention, FIGS. 2 and 3 are flowcharts explaining the operation of the electronic exposure control device of FIG. 1, and FIG. Figure 27 shows the relationship between A/D conversion data and the distance from the tip of the endoscope, and Figure 5 shows the A/D conversion meter'.
It is a figure explaining e protrusion. 11... Light receiving element, 12... Amplifying circuit, 13... Filter circuit, 14... A/D converter, 15...
Ilo boat, 16...CPU
0 Applicant's agent Patent attorney Suzue Takehiko Figure 1 I3 Figure 2 Osan E Tagureri Figure 4 Inner mussel, 1ΔL Hikari, 1se from! Giant Hina Figure 5 Field i■ ′;1j The Office Summons - In Anger Kazuo Wakasugi Tonoj,・1
1 display η is No. jiiB5ε-79082, the name of the older brother 1 and 1, 'electronic exposure side 1 practice: 3 Relationship with Nagisa Neutral who makes amends' (υ37) Garin・Gusu Kosho Kogyo Co., Ltd.・11 Agent (i, i'll! 11's λ・1 Full text of the specification '1. Amendment 1) 1' Details! :+ ”', tj・:'j' r i'J R
Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office1, Indication of the case Patent Application No. 1982-790822 Name of the invention Electronic exposure control device 3, Relationship with the Akane case to be amended Name of the patent applicant ( O:37) Olympus Optics 2r::h'; Co., Ltd. 4, Agent (i Supplement + - E's λ',] Details of Section 7, Abstract i (1) Page 1 of Mei 11 IIJ In the 20th line, 1-photoelectric signal > 4: is corrected to ``electrical signal.'' (3), jJ1 2nd line 2nd line
1 - In other words, 1 to 2 is incomplete or maximum 1 is the reflected light from the set collation light 2.
'l iJ-zuru 1゜(!1) Same second member 3rd line (this 1-optical telegraph si 1
Where is it (Electricity (No. 5) and RJ correction 1°C)) Same No. 2 Motorcycle No. 49-itH1 to All No. 5 <i
11'=This (1~1-1 small light emission will be stopped.) 1st) -1'' If incomplete, 1 light emission will be stopped, and Fu Guoguang will be 1.4 large light. If you set it early, it will be a disaster.
The setting has been changed to output the collimation light of ``;
-J iJ ni. (6) In the 17th line of the 3rd text, ``Correct the word ``optical telegraph father-1'' as 1 electricity 4:j:, , 1. (7) In the 11th line of the 4th text 1 photoelectric signal J is corrected to 1-electric signal. (8) Page 4, line 1, seedling box, line 6 (ko, rA/
D converter 14...processed. ”-[The A/D converter 14 converts the electrical signal into digital photometric data corresponding to the electrical signal. The photometric data of the A/D converter 14 is taken into the CPU 16L2 through the I10 port 15 at, for example, 1/100th of a second and processed. ” he corrected. (9) In the 15th line of the 4th page, 1, for example, "-1 or -1" is corrected to 1, for example, +1 column. (10) In the 19th line of page 4, the phrase ``stroboscopic light intensity'' is corrected to read ``strobe light intensity or lamp light intensity when the number of people is at its peak.''・ (11) In the second line of page 5, [Strobe light measurement J]
The text has been corrected to read "photometry of strobe light intensity or lamp light intensity at maximum output." (12) In the fourth line of page 5, the phrase "distributed light amount" is corrected to "light amount ratio." (13) Page 5, lines 13 to 15 E
~ Roho dimming is possible, and any light source can be controlled by one light source.
I am corrected. (14) "Photoelectric signal" in the 6th negative line 8th to 9th line
Correct it to 1-Electrical signal. (15) In the 19th and 20th lines of page 6, change the phrase "When the strobe device emits light in this state" to 1. In this state, the lamp light intensity is set to the maximum value. Correction and-
Ru. (1G) In the 20th line of page 6, the phrase "Small reflected light" is corrected by 51 to read "Reflected light of lamp light." (17) In the first and second lines of page 7, “Photoelectric signal 1
Correct it to ``1 electric signal''. (18) In the second line of page 8, the text ``For example, the light emission of a strobe device is stopped and J'' is corrected and overwritten as ``For example, the amount of light from the lamp is changed back to the amount of light during observation.''

Claims (1)

[Claims] 1) means for outputting a received light signal according to the amount of received light, means for A/D converting this received light signal output means, and this A/D
means for capturing the light reception data of the converting means in a first cycle and setting an exposure value from the light reception data and a predetermined constant; means for sequentially subtracting in small cycles;
Area "A": an electronic exposure control device comprising means for executing the end of photographing when the subtraction value of the means reaches a predetermined value.