JPH06258691A - Camera - Google Patents

Abstract

PURPOSE:To protect the eye of a photographer and to secure excellent visibility for a main object within a finder in the case where high luminance object exists in field. CONSTITUTION:In a camera provided with a division photometry means 100 performing photometry in every photometry area by dividing the field into plural photometry areas, and an optical system 102 guiding light from the object to the eye of the photographer, a division dimming means 103 provided in the optical path of the optical system 102 different from the optical path of the photometry means 100, having a dimming area corresponding to each photometry area of the means 100 and capable of dimming the light passing through the optical system 102 for every dimming area, and a control means 104 comparing the photometry output of each photometry area of the means 100 with a specified value, and dimming the light passing through the dimming area by the dimming means 103 for a dimming area corresponding to the photometry area whose photometry output exceeds the specified value are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera having a finder optical system equipped with a dimming device for dimming strong light from a high-brightness subject.

[0002]

2. Description of the Related Art In conventional cameras, when there is a high-luminance subject such as the sun in the field, a high-density filter is attached to the lens or the photographer wears sunglasses to dazzle the subject. It protects the eyes and protects the eyes from strong light.

However, with such a method, the entire viewfinder screen becomes dark, and it is difficult to secure good visibility for the main subject in the viewfinder.

An object of the present invention is to protect the eyes of the photographer and to ensure good visibility of the main subject in the viewfinder when there is a high-luminance subject in the field.

[0005]

The present invention will be described with reference to FIG. 1, which is a claim correspondence diagram. According to the invention of claim 1, the object field is divided into a plurality of photometric regions, and each photometric region is divided into a plurality of photometric regions. It is applied to a camera provided with a split photometry means 100 for performing photometry and an optical system 102 for guiding light from a subject to the photographer's eyes. Further, it is provided in the optical path of the optical system 102 different from the optical path of the split photometric means 100, and has a dimming area corresponding to each photometric area of the split photometric means 100, so that light passing through the optical system 102 is dimmed area. The dimming means 103 capable of dimming each and the photometric output of each photometric area of the split photometric means 100 are compared with a predetermined value, and for the dimming area corresponding to the photometric area where the photometric output exceeds the predetermined value, Control means 10 for dimming the light passing through the dimming area by the split dimming means 103.
4, and thereby achieve the above object. Also,
The divided dimming means 103A of the camera according to claim 2 makes the light transmittance of each dimming area variable, and the control means 104A responds to each photometric area according to the photometric output of each photometric area of the split photometric means 100. The light transmittance of the dimming area of the divided dimming means 103A is controlled.

[0006]

In the camera of the first aspect, when the photometric output of the divided photometric area exceeds a predetermined value, the light passing through the dimming area is dimmed with respect to the dimming area corresponding to the photometric area. This protects the eyes of the photographer and ensures good visibility of the main subject in the viewfinder when there is a high-luminance subject such as the sun in the field. Claim 2
In this camera, the light transmittance of the dimming area corresponding to each photometric area is controlled according to the photometric output of each photometric area. This protects the eyes of the photographer and ensures good visibility of the main subject in the viewfinder when there is a high-luminance subject such as the sun in the field.

[0007]

【Example】

—First Embodiment— FIG. 2 is a diagram showing the configuration of the first embodiment. The light flux from the subject that has passed through the taking lens 1 is reflected by the mirror 2 and guided to the focusing screen 3, and a subject image, that is, a finder image is formed on the focusing screen 3. This viewfinder image
Condenser lens 4, pentagonal roof prism (hereinafter simply referred to as penta prism) 5, and eyepiece lens 6
Observed by the photographer through. The finder image is split by the pentaprism 5 and relay lens 7
The light is also guided to the light receiving surface of the multi-photometric photoelectric light receiving element (hereinafter, simply referred to as a light receiving element) 8 via, and a secondary image of the subject is formed on this light receiving surface.

Further, in the first embodiment, an electrochromic display plate (hereinafter simply referred to as an EC plate) 9 for dimming light from the finder image is provided between the pentaprism 5 and the eyepiece 6. To provide. This EC board 9
It has the same size as the field of view of the finder screen on the focusing screen 3. Since the EC plate 9 is installed between the pentaprism 5 and the eyepiece lens 6, it does not affect the photometry by the light receiving element 8.

FIG. 3 is a front view of the light receiving element 8. In the first embodiment, the object scene is divided into five photometric regions and photometry is performed for each photometric region. The light receiving element 8 is divided into five light receiving portions PD0 to PD4 corresponding to these light measuring areas, and the light receiving areas PD0 to PD4 measure the respective light measuring areas to perform analog photoelectric conversion.

FIG. 4 is a front view of the EC plate 9. This EC
The plate 9 is provided with dimming regions corresponding to the above-mentioned five photometric regions, and EC0 to EC4 are segments of each dimming region. The segment EC0 of the EC plate 9 corresponds to the photometric area of the light receiving unit PD0. Similarly, the segment EC1 corresponds to the light receiving portion PD1, the segment EC2 corresponds to the light receiving portion PD2, the segment EC3 corresponds to the light receiving portion PD3, and the segment EC4 corresponds to the light receiving portion PD4.

Each segment EC0 to EC4 on the EC plate 9
Can be independently driven by the ECD driver described later, and are transparent when not driven, and segment EC0 to
When a voltage is applied to the EC4 to drive it, the density becomes high and it becomes translucent. As a result, the EC plate 9 can reduce the light from the finder image that passes through each light reduction area.

FIG. 5 is a block diagram showing the configuration of the control circuit of the first embodiment. Light receiving parts PD0 to PD of the light receiving element 8
The analog photometric signal No. 4 is converted into digital photometric signals P0 to P4 by the photometric circuit 11 and output to the microcomputer 12. The microcomputer 12
Reference level P preset in the photometric signals P0 to P4
When there is a high-luminance photometric signal exceeding th0, the segments EC0 to EC of the EC plate 9 corresponding to the photometric region
A voltage application command signal for applying a voltage to 4 is output. Here, the reference level Pth0 is set to 16 EV, for example.

The ECD driver 13 applies a drive voltage to the segments EC0 to EC4 which have received the voltage application command signal, and makes the segment semi-transparent with high density. As a result, the light from the area in which a high-luminance subject that exceeds the reference level Pth0 is present is dimmed by the EC plate 9.

FIG. 6 is a flow chart showing a control program of the microcomputer 12. The operation of the first embodiment will be described with reference to this flowchart. The microcomputer 12 starts executing this control program when a release button (not shown) is half-pressed. First, in step S1, the register n indicating the numbers of the photometric signals P0 to P4 is reset to 0, and the process proceeds to step S2. In step S2, the photometric signal P0 of the light receiving portion PD0 is input from the photometric circuit 11, and it is determined whether or not the reference level is Pth0 or higher. If the reference level is Pth0 or higher, the step S2 is performed.
3. If not, proceed to step S4. In step S3, the voltage application command signal for the segment EC0 of the EC plate 9 is output to the ECD driver 13, and the process proceeds to step S4. In step S4, it is determined whether or not the register n is 4, that is, whether or not the processing for all the photometric signals P0 to P4 is completed, and when completed, the execution of the program is terminated, and if there is an unprocessed photometric signal, the step is performed. Proceed to S5. In step S5, the value of the register n is incremented, the process returns to step S2, and the above process is repeated for the next photometric signal.

FIG. 7A shows a finder screen when the sun is present in a part of the field, and FIG. 7B shows the sun in the finder screen when the EC plate 9 is operated. The state where the light from the area is dimmed is shown.

FIG. 8A shows a viewfinder screen in the case where the sun and a high-brightness subject reflecting the light of the sun exist in a part of the field, and FIG. 8B shows the EC plate 9 in operation. The light from the area where the high-brightness subject is present in the viewfinder screen is dimmed.

As described above, when the photometric output of the divided photometric area exceeds the predetermined value, the light of the object image passing through the segment of the dimming area corresponding to the photometric area is dimmed. Therefore, even if there is a high-brightness subject such as the sun in the scene, it can protect the eyes of the photographer and
Good visibility can be secured for the main subject in the viewfinder.

Second Embodiment Next, a second embodiment for controlling the light transmittance of the EC plate according to the photometric signal level will be described. The configuration of the camera of the second embodiment is similar to that shown in FIG. 2, and illustration and description thereof will be omitted. The area division of the object scene in the second embodiment is similar to that in the first embodiment.

FIG. 9 is a block diagram showing the configuration of the control circuit of the second embodiment, and FIG. 10 is an enlarged view of the EC board. In addition,
The same components as those in the first embodiment shown in FIG. 5 are designated by the same reference numerals, and different points will be mainly described. As shown in FIG. 10, the EC plate 23 of the second embodiment has five dimming regions EC10 to E corresponding to the above-mentioned five-divided regions of the object scene.
Divided into C14, each dimming area is composed of a plurality of segments. Therefore, each dimming area of the EC plate 23 corresponds to each of the light receiving portions PD0 to PD4 of the light receiving element 8. The microcomputer 21 is an ECD
The driver 22 can be controlled to drive the individual segments included in each dimming region of the EC plate 23. Similar to the first embodiment, each segment is almost transparent when it is not driven, and becomes high-concentration and semitransparent when a driving voltage is applied. FIG. 11 shows a state in which a drive voltage is applied to each half segment of the dimming regions EC10 and EC11 to reduce the light transmittance of the dimming regions EC10 and EC11.

The microcomputer 22 ranks as follows according to the signal levels of the photometric signals P0 to P4. In this second embodiment, three reference levels Pt
h0, Pth1 and Pth2 are provided, each 16E
Set V, 18EV, and 20EV. Then, if the signal level of each photometric signal P0 to P4 is in the range of (1) Pth0 ≦ (P0 to P4) <Pth1, the dimming area of the EC plate 23 corresponding to the light receiving unit that has output the photometric signal. On the other hand, 1 / included in the dimming area
The voltage application command signal for decreasing the light transmittance in the dimming region is output by increasing the density of the third segment. (2) If Pth1 ≦ (P0 to P4) <Pth2, the dimming area of the EC plate 23 corresponding to the light receiving unit that outputs the photometric signal is 2 / included in the dimming area.
The voltage application command signal for decreasing the light transmittance in the dimming region is output by increasing the density of the third segment. (3) If it is in the range of Pth2 ≦ (P0 to P4), all the segments included in the dimming area are set higher than the dimming area of the EC plate 23 corresponding to the light receiving unit that outputs the photometric signal. A voltage application command signal for reducing the light transmittance of the dimming region as the density is output.

The ECD driver 22 applies a drive voltage to the corresponding segment according to a voltage application command signal from the microcomputer 21. The segment to which the drive voltage is applied has a high density, and the light transmittance of the entire dimming region is reduced. Therefore, the greater the number of segments to which the drive voltage is applied, the lower the light transmittance of the dimming region.

FIG. 12 is a flow chart showing a control program of the microcomputer 21. The operation of the second embodiment will be described with reference to this flowchart. The microcomputer 21 starts executing this control program when a release button (not shown) is half-pressed. First, in step S11, the photometric signals P0 to P4
Register n indicating the number of 0 is reset to 0 and step S
Proceed to 12. In step S12, the photometric signal P0 of the light receiving unit PD0 is input from the photometric circuit 11 and the reference level Pth0 is input.
Whether or not it is above is determined. If it is equal to or higher than the reference level Pth0, the process proceeds to step S13, and if not, step S18.
Go to. In step S13, it is determined whether or not the photometric signal P0 is equal to or higher than the reference level Pth2. If it is equal to or higher than the reference level Pth2, the process proceeds to step S14, and if not, the process proceeds to step S15.

When the photometric signal P0 is equal to or higher than the reference level Pth2, the voltage application command signals of all the segments in the dimming area EC10 of the EC plate 23 corresponding to the light receiving portion PD0 of the light receiving element 8 are sent to the ECD driver 22 in step S14. Output to. On the other hand, in step S15, it is determined whether or not the signal level of the photometric signal P0 is within the range of Pth2> P0 ≧ Pth1, and if it is within the range, the process proceeds to step S16, and if not, the process proceeds to step S17. When the level of the photometric signal P0 is Pth2> P0 ≧ Pth1, step S
EC plate 23 corresponding to the light receiving portion PD0 of the light receiving element 8 at 16
The voltage application command signal of the ⅔ segment in the dimming area EC10 is output to the ECD driver 22. On the other hand, when the photometric signal P0 is smaller than the reference level Pth1, E corresponding to the light receiving portion PD0 of the light receiving element 8 is obtained in step S17.
The voltage application command signal of the 1/3 segment in the dimming area EC10 of the C plate 23 is output to the ECD driver 22.

Step S14 or S16 or S17
When the voltage application command signal is output at, the value of the register n is 4 in step S18, that is, all the photometric signals P0 to P0.
It is determined whether or not the above process is completed with respect to P4, and if the process is completed, the execution of the program is terminated, and if not, the process proceeds to step S19. In step S19, the value of register n is incremented and the process returns to step S12.
The above process is repeated for the next photometric signal.

As described above, among the plurality of segments in the dimming region corresponding to each photometric region, the number of the segments to be dimmed is changed according to the photometric output of each photometric region, and the light transmission of the dimming region is performed. Since the ratio is controlled, it is possible to protect the eyes of the photographer even if there is a high-brightness subject such as the sun in the field, and to ensure good visibility for the main subject in the viewfinder. You can

In each of the above-described embodiments, the dimming operation of the electrochromic display plate is performed when the photometric signal is at the reference level Pth0 = 16 EV or more. Is not limited to the above embodiment. For example, a plurality of reference levels for determining whether or not to perform the dimming operation may be provided, and the photographer may arbitrarily switch.

Further, in the above-described second embodiment, the photometric signal is determined based on the three reference levels and the electrochromic display panel is controlled. However, the photometric signal is provided by providing two or four reference levels. The electrochromic display panel may be controlled according to the determination result.

Further, in the second embodiment, the number of the segments to which the drive voltage is applied to increase the density is changed according to the determination result of the photometric signal, but the electrochromic display plate is changed according to the level of the photometric signal. It is also possible to continuously change the drive voltage value applied to the light source to control the light transmittance of the dimming region.

The division number and the division mode of the multi-photometric photoelectric receiving element and the electrochromic display plate are not limited to those in the above embodiment. Further, the installation location of the multi-photometric photoelectric light receiving element is not limited to the above-described embodiment, and for example, it is installed in the lower part (bottom) of the camera, and the light beam that has passed through the mirror 2 is installed in the lower part using the sub-mirror. You may lead to. In this case, the installation position of the electrochromic display plate is not limited to the position of the above-described embodiment, and may be arranged anywhere in the optical path from the mirror to the eyepiece lens, such as near the focusing plate.

In each of the above-mentioned embodiments, the electrochromic display plate is used to reduce the strong light from the focusing plate, but it may be reduced by a liquid crystal display element, an optical filter, a shutter or the like. Good.

In each of the above-mentioned embodiments, the single-lens reflex camera has been described as an example, but the present invention can be applied to the twin-lens reflex camera. The shutter system may be a focal plane shutter or a lens shutter.

In the structure of the above embodiment, the multi-photometric photoelectric light receiving element 8 serves as a split photometric means, the focusing plate 3 serves as a focusing plate, and the mirror 2, the condenser lens 4, the pentagonal roof prism 5 and the eyepiece 6 serve as an optical system. The electrochromic display plates 9 and 23 serve as split dimming means, the microcomputers 12 and 21 and the ECD driver 13,
22 constitutes control means respectively.

[0033]

As described above, according to the invention of claim 1, in the optical path different from the optical path of the split photometric means,
In addition, a divisional dimming unit having a dimming region corresponding to each photometry region of the division photometry unit is provided in the optical path of the finder optical system, and when the photometry output of the division photometry region exceeds a predetermined value, the reduction corresponding to that photometry region is performed. Since the light passing through the dimming area is dimmed relative to the light area, the eyes of the photographer can be protected even if there is a high-brightness subject such as the sun in the scene, and the Good visibility can be secured for the main subject. Further, according to the present invention, since the dimming means is provided in an optical path different from the optical path of the split photometric means, even if the dimming means dims, it does not affect the photometric value and accurate photometric output. Can be obtained. Further, according to the invention of claim 2, the light transmittance of the dimming region corresponding to each photometric region is controlled according to the photometric output of each photometric region. Even if there is a brightness subject, it is possible to protect the eyes of the photographer and ensure good visibility with respect to the main subject in the viewfinder.

[Brief description of drawings]

FIG. 1 is a complaint correspondence diagram.

FIG. 2 is a diagram showing a configuration of a first embodiment.

FIG. 3 is a front view of a multi-photometric photoelectric light receiving element.

FIG. 4 is a front view of an electrochromic display plate.

FIG. 5 is a block diagram showing a configuration of a control circuit of the first embodiment.

FIG. 6 is a flowchart showing a control program of the microcomputer of the first embodiment.

FIG. 7A is a view showing a viewfinder screen when the sun is present in a partial area of the object field, and FIG. 7B is an area where the sun is present in the viewfinder screen by operating the electrochromic display plate. The figure which shows the state which dimmed the light from.

FIG. 8A is a view showing a viewfinder screen in the case where the sun and a high-brightness subject reflecting the light of the sun are present in a partial area of the object field, and FIG. 8B is a view showing an electrochromic display board operated. The figure which shows the state which dimmed the light from the area | region where the high-intensity subject exists in the viewfinder screen.

FIG. 9 is a block diagram showing a configuration of a control circuit according to a second embodiment.

FIG. 10 is an enlarged view of an electrochromic display plate.

FIG. 11 is a diagram showing a state in which a driving voltage is applied to a half segment in a part of the dimming region of the electrochromic display plate to reduce the light transmittance of these dimming regions.

FIG. 12 is a flowchart showing a control program of the microcomputer of the second embodiment.

[Explanation of symbols]

 1 Photographing lens 2 Mirror 3 Focus plate 4 Condenser lens 5 Pentagonal roof prism (Penta prism) 6 Eyepiece lens 7 Relay lens 8 Multi-photometric photoelectric light receiving element (light receiving element) 9,23 Electrochromic display panel (EC plate) 11 Photometric circuit 12,21 Microcomputer 13,22 ECD driver 100 Divided photometric means 102 Optical system 103,103A Divided dimming means 104,104A Control means PD0-PD4 Light receiving part EC0-EC4 segment EC10-EC14 Dimming area P0-P4 Photometric signal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiji Osawa 3 2-3 Marunouchi, Chiyoda-ku, Tokyo Inside Nikon Corporation

Claims (2)

[Claims] 1. A camera provided with a split photometric means for dividing a field into a plurality of photometric areas and performing photometry for each photometric area, and an optical system for guiding light from a subject to a photographer's eyes. It is provided in the optical path of the optical system different from the optical path of the split photometric means, and has a dimming area corresponding to each photometric area of the split photometric means, and the light passing through the optical system is provided for each dimming area. Divided dimming means capable of dimming, and comparing the photometric output of each photometric area of the divided photometric means with a predetermined value, and dimming the dimming area corresponding to the photometric area where the photometric output exceeds the predetermined value. A camera, comprising: control means for reducing the light passing through the area by the divided light reduction means. 2. The camera according to claim 1, wherein the divisional dimming unit has a variable light transmittance for each of the dimming regions, and the control unit controls the photometry of each photometric region of the divisional photometric unit. A camera which controls the light transmittance of the dimming region of the divided dimming means corresponding to each photometric region according to the output.