JPS60203077A - Still picture photographing device - Google Patents

Abstract

PURPOSE:To obtain a still picture without causing any failure by controlling a titled device so as to take at least two still pictures by changing the quantity of light incident on a solid-state image pickup element with one photographying operation. CONSTITUTION:Light from a light source unit 10 is made incident on the light guide of an endoscope 18 through a condenser lens 26. An image in the coelom is formed by an objective lens 22 and passes through an image guide 24 and enters an electronic camera 26 connected to an eyepiece of the endoscope 18, and then enters a solid-state image pickup element 32 made up of CCD through a photographing lens 28 and a diaphragm 30. By depressing a photographing start button 34, a controlling signal is supplied from a controlling signal generator 36 to an actuator 38 that controls the value of the diaphragm 30, a driver 40 that outputs clock pulse that controls the action of the element 32 and a lamp of the light source unit 10. An output of the element 32 is supplied to a magnetic disk memory 42. The value of the diaphragm 30 is set to the first value synchronizing with starting of photographing, and the element 32 is made to an accumulation mode and then to reading mode. Then, the diaphragm value is set to the second value which is lower than the first value, and accumulation and reading of the element 32 is performed.

Description

Detailed Description of the Invention 31 Technical Field The present invention relates to a still image photographing device using a solid-state image sensor.

3.2 Prior Art Conventionally, in medical examination using an endoscope, not only observation with the naked eye but also photography is performed for comparative observation. The angle of the stomach is particularly susceptible to cancer and is often photographed.

In recent years, still images have been electronically recorded using electronic cameras using solid-state imaging devices such as CCDs, instead of optical photography using silver halide films. Although such a still image photographing device has various advantages such as not requiring a developing process, it has a drawback that the dynamic range regarding brightness is narrow. Unfortunately, because the interior of the body cavity, such as the angle of the stomach, has severe irregularities, the concave parts are photographed too dark and the convex parts too bright, making it impossible to diagnose these irregularities. There is a lot of water in the body cavity, and the light from the light source may reflect on the water surface. In this case, halation occurs on the screen, making it impossible to perform a diagnosis. If photography fails in this way, it is necessary to insert the endoscope into the patient and take photographs again in order to make an accurate diagnosis, but this has the disadvantage of causing pain for the patient and increasing the doctor's time. .

33 Purpose An object of the present invention is to provide a still image photographing device capable of photographing still images without failure.

3.4 Overview According to the still image photographing device of the present invention, at least two still images are continuously photographed by changing the amount of light incident on the solid-state image sensor upon one photographing start instruction.

35 Embodiment Hereinafter, an embodiment of the still image photographing device according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration when the present invention is applied to an endoscope. Light source unit 1
The light from the rung 12 in 0 is incident on the light guide 20 of the endoscope 18 via the condensing mirror 14 and the condensing lens 16. An image inside the body cavity is formed by an objective lens 22, transmitted through an image guide 24, and entered into an electronic camera 26 connected to an eyepiece of an endoscope 18. electronic camera 26
The incident optical image is incident on a solid-state image sensor 32 made of COD via a photographing lens 28 and an aperture 30.

The output of the control signal generator 36, which generates various control signals in response to the depression of the shooting start button 34 provided on the outside of the electronic camera 26, is used by the actuator 38, which controls the aperture value of the aperture shutter 30, and the solid-state imaging Hata J132. It is supplied to a driver 4o that outputs clock pulses that control operations. Further, the output of the control signal generator 36 is also supplied to the lamp 12 of the light source unit 10 via the endoscope 18 . The image signal output from the solid-state image sensor 32 is supplied to the magnetic disk memory 42.

The operation of this embodiment will be explained with reference to the time charts shown in FIGS. 2(a) to 2(d). Control signal generator 36
supplies control signals shown in FIGS. 2(b), (c) and (d) to the rung 12, actuator 38 and driver 40, respectively. Before starting photography, the lamp 12 emits light with a small amount of light. When an instruction to start shooting is given as shown in FIG. 2 (=), the level of the control signal a41 to run fx2 is increased as shown in FIG. increases. In synchronization with the start of photography, the level of the control signal to the actuator 38 becomes the second level B as shown in FIG. Set. When photographing is started, the control signal generator 10 supplies a control signal to the driver 40 to set the solid-state image sensor 32 first in the accumulation mode and then in the readout mode, as shown in FIG. 2(d). . As a result, one still image is taken at the first aperture value,
The image signal read from the solid-state imaging probe 32 is recorded on the magnetic disk memory 42. When the reading of the first image signal is completed, the control signal generator 36 controls the actuator 3.
8 as shown in FIG. 2(C), and the aperture value of the aperture pso is set to a second value different from the first value. In this state, the control signal generator 36
As shown in FIG. 2(d), a control signal is supplied to the driver 40 to first set the solid-state image sensor 32 to the accumulation mode and then to the continuous output mode. Accordingly, one still image is taken even at the second aperture value, and two still images are taken by changing the amount of light incident on the solid-state image sensor 32.

As described above, according to this embodiment, two still images are taken consecutively and at different aperture values in response to a single shooting start instruction. Therefore, even if the subject is too bright or too dark, at least one image will be taken correctly, and no failure will occur. This is particularly effective in cases such as endoscopic photography, where the range of brightness of the subject is wide and it is difficult to correct the photographic orientation. In addition, operability is good because two images are automatically taken with one photographing start instruction.

Next, another embodiment of the still image photographing device according to the present invention will be described. The configuration of the second embodiment is the same as that of the first embodiment shown in FIG. 1, and only its operation will be explained with reference to the time charts of FIGS. 3(a) to 3(d). When an instruction to start shooting is given (FIG. 3(a)), the control signal to the lamp 12 is set to the second level D as shown in FIG. 3(b), and the run f12 is started.
Let the amount of light emitted be the first large amount of light. In the second embodiment, as shown in FIG. 3(C), since the control signal to the actuator 3B is constant, the aperture p value of the aperture 30 is constant. In addition to the first light emission amount, the run f12 is controlled (M number generator 36
1 by controlling the driver 40 as shown in FIG. 3(d).
Capture the first still image.

When this first photograph is completed, the control signal generator 36
As shown in Figure (b), the control signal to the lamp 12 is set to a second level D, and the amount of light emitted from the lamp 12 is set to a second large amount of light different from the first large amount of light. When the rung 12 emits the second amount of light, the control signal generator 36 controls the dry nog 40 to take a second still image as shown in FIG. 3 (S).

In this way, in the second embodiment, the aperture value υ of the aperture shutter 30 is constant, but the lamp 120 in the light source unit 10
By changing the amount of light emitted, the amount of light incident on the solid-state imaging probe 32 is changed, and two still images are taken continuously. Also in this manner, similarly to the first embodiment, photographing can be performed without failure.

Next, the operation of the third embodiment will be explained with reference to the time charts shown in FIGS. 4(a) to 4(d). The configuration of the third embodiment is also the same as that shown in FIG. In the third embodiment, the camera 7012 responds to the shooting start instruction (FIG. 4(a)).
, the control signal supplied to actuator 38 can be set to a predetermined level.

Unlike the above-described embodiment, this level is - during the shooting of two still images. The control signal generator 36 is the driver 4
As shown in FIG. 4(d), the solid-state imaging probe 32 is sequentially set to the storage/readout mode for the first image and the storage/readout mode for the second image. The readout period is specific to the solid-state image sensor 32 and is the same for the first and second images. However, the storage period is 6D, which is the same as exposure in general photography, and is variable depending on the brightness of the subject. In this embodiment, the accumulation periods for the first and second shots are different.

In this way, according to the third embodiment, by changing the storage time of the solid-state image sensor, the amount of light incident on the solid-state image sensor is changed. This produces the same effect as the embodiment described above.

In the second embodiment, the run fl, ? Although the amount of light emitted by the light source is changed by the control signal, it is also possible to provide separate lamps with different amounts of light emitted and switch the amount of light emitted by a mirror or the like so that the light enters the light guide. Alternatively, a discharge tube may be used as the light source lamp, and capacitors of different capacities may be used to discharge light. The configuration of the light source unit 10 in this case is shown in FIG.

At one end of the discharge tube 50, a carrier/mother 52.5 of different capacity is installed.
One end of capacitor 4 is connected, and the other end of capacitor 52 and 54 are connected to the other end of discharge tube 50 via changeover switch 56. The signal to the discharge tube 5o and the switch 56
The switching control signal to the electronic camera is generated by the control signal generator (
(not shown in FIG. 5). Since the amount of light emitted by the discharge tube 50 depends on the discharge current, the discharge tube 50 can be lit by switching between the canisters 52 and 54 having different capacities, and photographing can be performed twice, as in the above embodiment. Additionally, two still images can be captured by changing the amount of light incident on the solid-state image sensor.

This invention is not limited to the embodiments described above, but can be modified in various ways. For example, the number of consecutive images to be photographed in one photographing start instruction operation is not limited to two, but may be three or more. Furthermore, although the solid-state imaging element performs storage and readout separately, the second image may be stored during the first image readout period. Changing the amount of light incident on the solid-state image sensor is not limited to the above-mentioned means. Furthermore, it goes without saying that the present invention can be applied to an endoscope having a solid-state image sensor at its tip.

3.6 Effects of the Invention According to the present invention, at least two still images of the same subject can be photographed in succession by changing the amount of light incident on the solid-state image sensor in - times of photographing start instruction operations. A still image capture device is provided. Therefore, even objects with large differences in brightness and darkness can be photographed without failure.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a first embodiment of a still image photographing device according to the present invention, FIGS. 2(-) to (d) are time charts showing the operation of the first embodiment, and FIG. 3(a) ~(d) is a time chart showing the operation of the second embodiment, and FIG. 4(a)~
(d) is a time chart showing the operation of the third embodiment, m5
The figure shows the configuration of a modified example of the invention. 12...Lamp, 20-...Light guide, 22...
- Image guide, 30... Aperture, 32... Solid-state image sensor, 34... Release button, 36... Control signal generator. Applicant's agent Patent attorney Tsuboi Relief Figure 1 Figure 2 Figure 3 Figure 11111-1 Figure 5

Claims (4)

[Claims] (1) A still image photographing device that photographs at least two still images by changing the amount of light incident on a solid-state image sensor in one photographing start operation. (2) The still image photographing device according to claim 1, wherein the amount of light incident on the solid-state image sensor is changed by an aperture. (3) The still image photographing device according to claim 1, wherein the amount of light incident on the solid-state image sensor can be changed by changing the amount of light from a light source. (4) The still image photographing device according to claim 1, wherein the amount of light incident on the solid-state image sensor is changed by changing the charge storage time of the solid-state image sensor.