JPH0843939A - camera - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a camera capable of obtaining proper exposure over a wide range of shooting conditions while simplifying a shutter mechanism. [Structure] Photographing lens 21 for forming an optical image of a subject
Is arranged on the optical axis of the photographing lens 21 and the photographing lens 2
1 reflects the incident light flux and the direction of the reflected light flux is the first
Of the spatial light modulation element that can be changed in the direction of, and the other direction, the photosensitive member 23 that is arranged in the first direction, and the area of the opening that is arranged in the photographing lens 21 and through which the light flux passes And a driving means 24 for setting the direction of the reflected light flux to the first direction only during the exposure period of the photosensitive member 23 and to other directions during the exposure period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera which uses a spatial light modulator for changing the direction of a reflected light beam in a shutter mechanism and has a diaphragm mechanism.

[0002]

2. Description of the Related Art In general, a pan-focus photograph in which both a near view and a distant view are in focus is often seen in landscape photography. Such photographs are taken by closing the camera diaphragm and increasing the depth of field.

Further, as is often seen in portrait photographs, in order to blur a complicated background, the aperture of the camera is opened to make the depth of field shallow. In this way, by changing the aperture of the camera, it is possible to limit the amount of light and realize various shooting expressions.

FIG. 8 is a diagram showing a camera of this type.
In the figure, a photosensitive member 2 is arranged on the image forming surface of the taking lens 1, and a quick return mirror 3 is arranged between the taking lens 1 and the photosensitive member 2 in an inclined manner. A focal plane shutter 4 including a front curtain 4a and a rear curtain 4b is arranged immediately before the photosensitive member 2, and a shutter drive circuit 5 is connected to the focal plane shutter 4 and the quick return mirror 3.

A diaphragm 6 is arranged between the taking lens 1 and the quick return mirror 3, and the diaphragm driving circuit 6a is connected to the diaphragm 6. A control circuit 7 is connected to the shutter drive circuit 5 and the diaphragm drive circuit 6a, and a shutter button 7a, a memory 7b, and a photometric unit 8 are individually connected to the control circuit 7.

A pentaprism 9 is arranged at a position where the light flux from the taking lens 1 is reflected by the quick return mirror 3 to form an image. In the camera having such a configuration, the incident light from the subject is condensed by the photographing lens 1 and reflected by the quick return mirror 3 to form an optical image on the lower surface of the pentaprism 9. This optical image is reflected inside the pentaprism 9 and viewed by the photographer as an erect image.

When the shutter button 7a is pressed halfway down, the control circuit 7 takes in the photometric value of the object by the photometric section 8 and stores the exposure period and the aperture value stored in advance from the memory 7b in accordance with the photometric value. Read the combination of and.

When the shutter button 7a is fully pressed, the control circuit 7 controls the diaphragm driving circuit 6a to match the diaphragm 6 with the read diaphragm value. Further, the control circuit 7 activates the shutter drive circuit 5 to flip up the quick return mirror 3 so that the incident light flux from the photographing lens 1 reaches the focal plane shutter 4.

In this focal plane shutter 4,
The front curtain 4a and the rear curtain 4b move laterally with a time lag. The incident light flux passes between the front curtain 4a and the rear curtain 4b (hereinafter referred to as "slit") to expose the photosensitive member 2 to light.

At this time, the slit spacing S is equal to the curtain speed V.
From the read exposure period T and S, S = T · V is set.

In this way, photographing is performed in accordance with the aperture value and the exposure period which are predetermined according to the photometric value.

[0012]

However, in the conventional camera, if the slit interval is narrowed and the shutter speed is increased, uneven exposure occurs due to uneven speed of the curtain speed.

Further, since the mass of movable parts such as the front curtain 4a and the rear curtain 4b is large, it is difficult to increase the curtain speed. Due to such restrictions, it is difficult to realize a high-speed shutter, and the limit value of the shutter speed is about 1/2000 to 1/12000 seconds.

Therefore, when a subject having high brightness such as in fine weather is photographed with a wide aperture using a photographing lens having a small open F-number, overexposure occurs due to a low shutter speed limit value, and proper exposure is performed. There was a problem that was not obtained.

Further, in order to increase the shutter speed limit value, a two-stage brake mechanism is required to increase the number of batteries to increase the shutter drive voltage and to brake the moving parts that have reached high speed. become. Therefore, if the shutter speed is increased to widen the shooting conditions for obtaining the proper exposure, there is a problem that the shutter mechanism becomes complicated.

Accordingly, it is an object of the present invention to provide a camera which can obtain a proper exposure over a wide range of photographing conditions while simplifying the shutter mechanism.

[0017]

According to a first aspect of the present invention, there is provided a photographing lens for forming an optical image of a subject, and a photographing lens arranged on the optical axis of the photographing lens to reflect an incident light beam from the photographing lens. , And the spatial light modulation element in which the direction of the reflected light beam can be changed between the first direction and the other direction, the photosensitive member arranged in the first direction, and the light beam which is arranged in the photographing lens and passes therethrough. An aperture stop whose area can be changed, and a driving means for setting the direction of the light flux reflected by the spatial light modulator to the first direction only during the exposure period of the photosensitive member and other directions during the exposure period It is characterized by

According to a second aspect of the present invention, in the camera according to the first aspect, the spatial light modulation element is a digital micromirror element in which a plurality of mirrors are arranged on a surface of a substrate in a variable tilt. Is characterized by.

According to a third aspect of the present invention, in the camera according to the first or second aspect, a storage unit that stores a combination of an exposure period and an aperture value that is predetermined according to the subject brightness, and the subject Measuring means for measuring the brightness,
An exposure control unit that reads out a combination of an exposure period and an aperture value from the storage unit according to the subject brightness measured by the measurement unit, and sets the exposure period to the exposure period in the drive unit; A diaphragm driving unit that changes the area of the aperture of the diaphragm according to the aperture value is set.

According to a fourth aspect of the present invention, a plurality of mirrors are arranged so as to be tiltable on a surface of a photographing lens for forming an optical image of a subject and a substrate arranged to be inclined with respect to the optical axis of the photographing lens. For a digital micromirror element, a photosensitive member arranged in a first direction in which the optical axis of the taking lens is geometrically regularly reflected on the upper surface of the substrate, and a predetermined exposure period and aperture value, During the exposure period, only the reflected light flux of the mirror, which is predetermined according to the aperture value, is in the first direction, and during the exposure period, the reflected light flux of all the mirrors is in the other direction. And driving means.

The invention described in claim 5 is the camera described in claim 4, characterized in that the predetermined mirrors are distributed in a concentric shape on the surface of the substrate. According to a sixth aspect of the present invention, in the camera according to the fourth aspect, the predetermined mirrors are evenly distributed on the surface of the substrate.

[0022]

In the camera of the first aspect, the light amount and the depth of field are adjusted by changing the aperture area of the diaphragm.

When the exposure period starts, the driving means changes the reflection direction of the spatial light modulator to the first direction. The light flux reflected in this way is applied to the photosensitive member in the first direction. When the exposure period ends, the driving unit changes the reflection direction of the spatial light modulation element to another direction to divert the light flux from the photosensitive member.

In this way, it is possible to realize a camera that exposes the photosensitive member by an exposure amount determined by the amount of light passing through the diaphragm and the exposure period. With such a camera, the front curtain, the rear curtain,
A movable part having a large mass and a large displacement such as a quick return mirror or a lens shutter is unnecessary, and a high-speed shutter can be realized while omitting the shutter drive mechanism.

According to the second aspect of the present invention, as the spatial light modulation element, a digital micromirror element in which a plurality of mirrors are arranged on the substrate in a variable tilt is used. By dividing the reflecting surface into a plurality of mirrors, the mass of the mirror alone is small and the displacement is small. Therefore, the time required to change the direction of the reflected light flux is shortened, and a faster shutter can be realized.

In the camera of the third aspect, the exposure control means reads out the predetermined aperture value and exposure period from the storage means based on the subject brightness measured by the measuring means. The diaphragm driving means changes the aperture area of the diaphragm according to the diaphragm value to limit the light quantity. The driving means exposes the photosensitive member with the direction of the reflected light flux in the first direction only during this exposure period. In this way, photographing is performed in accordance with the aperture value and the exposure period stored in the storage means in advance.

In the camera of the fourth aspect, the substrate of the digital micromirror element is tilted, and the incident light flux is reflected by the mirrors arranged in parallel with the substrate to expose the photosensitive member. With such a configuration, an optical image of the subject can be formed by focusing on a wide range of the photosensitive member. Further, by changing the number of mirrors that irradiate the photosensitive member with the reflected light flux, it is possible to change the amount of light applied to the photosensitive member, and it is possible to substitute the conventional diaphragm mechanism.

In the camera of the fifth aspect, the diameter of the reflected light flux is limited by making the distribution of mirrors that irradiate the reflected light flux on the photosensitive member concentric. Therefore, the function of the conventional iris diaphragm (iris diaphragm) can be substituted.

According to the sixth aspect of the present invention, the mirror that irradiates the photosensitive member with the reflected light flux is a uniformly distributed mirror, so that the passing light amount can be changed without changing the diameter of the reflected light flux. . Therefore, the function of the conventional ND filter (neutral density filter) can be substituted.

[0030]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention.

First, an example of the digital micromirror element 10 used in this embodiment will be described first. The digital micromirror device is based on “Nikkei Electronics 19
93.6-21 "(p. 65, published by Nikkei BP).

FIG. 2 is a diagram showing an example of a digital micromirror element. FIG. 2A is a top view of the device. On the surface of the substrate 10a, a minute aluminum mirror 11 having a side of about 17 μm is laid on, for example, about 640 × 480 pixels.

2B to 2D are sectional views of the aluminum mirror 11 in the diagonal direction (AA '). Posts 12a and 12b are projected on the substrate 10a, and diagonals of the aluminum mirror 11 are individually supported by the posts 12a and 12b. Electrodes 13 and 14 are arranged on the substrate 10a so as to face the other diagonal of the aluminum mirror 11.

In the digital micromirror device having such a structure, the aluminum mirror 11 is mounted on the substrate 10a when the columns 12a and 12b and the electrodes 13 and 14 have the same potential.
Parallel to (Fig. 2 (b)).

When a potential difference (for example, 5 V) is applied between the support columns 12a and 12b and the electrode 13, the Coulomb attractive force causes the aluminum mirror 11 to tilt toward the electrode 13 side (FIG. 2 (c)).

On the other hand, when a potential difference is applied between the columns 12a and 12b and the electrode 14, the aluminum mirror 11 tilts toward the electrode 14 side (FIG. 2 (d)). In this way, the voltage applied to the electrodes 13 and 14 tilts the individual aluminum mirrors 11,
The reflection direction of incident light can be changed.

The aluminum mirror 11 is provided on the substrate 10a.
Circuits for individually driving the aluminum mirror 1 are input to these circuits by inputting address information of the aluminum mirror 11 and others.
The inclination direction of 1 can be changed individually.

A circuit for storing the inclination direction (for example, a flip-flop circuit or a capacitor for storing the inclination direction depending on the presence / absence of electric charge) may be provided for each circuit for individually driving the aluminum mirror 11. In such a circuit, the inclination direction of the aluminum mirror 11 can be temporarily changed by storing the inclination direction of each circuit in advance and setting the voltages of the electrodes 13 and 14 at the same timing.

Since the aluminum mirror 11 has a small mass and a small displacement, the tilting time is as short as about 10 μsec. Further, since the reflection efficiency of such an aluminum mirror 11 is high, the light utilization efficiency is higher than that of liquid crystal.

The first embodiment of the present invention will be described below with reference to FIG. In the figure, the substrate 10a of the digital micromirror element 10, which is a spatial light modulator, is arranged on the optical axis of the taking lens 21 in an inclined manner.

The taking lens 21 is attached to the surface of the substrate 10a.
The photosensitive member 23 is arranged in a direction in which the optical axis of the is reflected geometrically. The digital micromirror element 10 has a drive circuit 24 for changing the inclination of an aluminum mirror 11 (not shown).
Is connected.

A diaphragm 25 is formed integrally with the taking lens 21, and the diaphragm driving circuit 25 for changing the aperture area of the diaphragm 25.
a is connected. Drive circuit 24 and diaphragm drive circuit 25
The control circuit 26 is connected to a, and the shutter button 26a, the memory 26b, and the photometric unit 27 are individually connected to the control circuit 26.

The control circuit 26 is composed of, for example, a microcomputer, and controls the exposure amount by linking the aperture value and the shutter speed. Further, the photosensitive member 23
A black light absorbing plate 2 is provided at a position where a light beam diverging from the light is emitted.
8 are arranged.

FIG. 3 is a flow chart showing the operation of the first embodiment. The operation of this embodiment will be described below with reference to this figure. In the state where the image is not taken, the drive circuit 24 applies a voltage to one electrode 13 of the digital micromirror element 10 to tilt all the aluminum mirrors 11 on the substrate 10a.

Therefore, the light beam incident from the taking lens 21 is deviated from the photosensitive member 23 and absorbed by the light absorbing plate 28. When the shutter button 26a is pressed halfway (step S1), the control circuit 26 takes in the photometric value of the subject measured by the photometric unit 27 (step S1).
2).

The control circuit 26 reads the combination of the exposure period and the aperture value from the memory 26b according to the photometric value (step S3). When the shutter button 26a is fully pressed (step S4), the control circuit 26 controls the diaphragm drive circuit 25a to adjust the aperture area of the diaphragm 25 to match the read diaphragm value (step S5). . further,
The control circuit 26 outputs a signal for starting the exposure period to the drive circuit 24.

Upon receipt of this signal, the driving means 24 changes the electrode 1
3, 14 are set to the same potential, and the aluminum mirror 11 is provided on each substrate 1
Parallel to 0a. The light flux incident from the taking lens 11 is limited in amount by the diaphragm 25, is reflected by the aluminum mirror 11, and exposes the photosensitive member 23 (step S6).

When the exposure period has elapsed (step S7),
The drive circuit 24 applies a voltage to the electrode 13 again, tilts the aluminum mirror 11 to the substrate 10a, and diverts the reflected light flux from the photosensitive member 23 (step S8).

By the above operation, photographing is performed in accordance with the aperture value and the exposure period stored in the memory 26b in advance. In the camera of the present embodiment described above, the conventional movable parts such as the front curtain and the rear curtain are not required, and the drive mechanism for these movable parts is also omitted.

Further, since the movable part composed of the minute aluminum mirror 11 has a small mass and displacement, the time required for starting and braking the shutter is reduced to about 10 μsec. Therefore, the shutter speed can be arbitrarily set by setting the exposure period, and a shutter speed higher than 1/2000 seconds to 1/12000 seconds can be realized. For example, if the exposure period is set to 1/20000 seconds, 1/20000
The shutter speed is 2 seconds.

As described above, by increasing the shutter speed, the range of photographing conditions for obtaining proper exposure is widened. For example, in fine weather, even when a lens having a small F number is used with an open aperture, it is possible to obtain a proper exposure with a high shutter speed.

Further, the drive circuit 24 is composed of, for example, a switch circuit for switching the voltage applied to the digital micromirror element 10 and a delay circuit for detecting the elapse of the exposure period, so that the shutter mechanism is simpler than the conventional one. Can be converted.

Further, in this embodiment, the taking lens 21
Of the photosensitive member 23 in the direction in which the optical axis of the
By arranging, it is possible to focus on a wide range of the photosensitive member 23.

Further, in the conventional shutter, since the exposure period is determined by driving the mechanical parts, the accuracy of the shutter speed is low and the exposure period varies widely. However, in this embodiment, by using a highly accurate delay circuit using a crystal oscillator or the like, the exposure period becomes accurate and a highly accurate shutter speed can be realized.

FIG. 4 is a diagram showing a second embodiment of the present invention. In the figure, the substrate 10 a of the digital micromirror element 10 is arranged on the image plane of the taking lens 21.

In the first reflection direction of the digital micromirror element 10, the lens 31 on the photosensitive member side is provided on the substrate 10.
A photosensitive member 23 is arranged in parallel with a, and at an image forming position on the extension.

Further, the digital micromirror element 10
For other reflection directions by, the finder side lens 32
Are arranged in parallel with the substrate 10a, and a finder screen 33 is arranged at an image forming position on an extension thereof.

Furthermore, the digital micromirror device 1
A drive circuit 24 for changing the inclination of the aluminum mirror 11 (not shown) is connected to 0. Further, a diaphragm 25 is formed integrally with the taking lens 21, and a diaphragm drive circuit 25a for changing the aperture area is connected to the diaphragm 25.

A control circuit 26 is connected to the drive circuit 24 and the diaphragm drive circuit 25a, and a shutter button 26a, a memory 26b, and a photometric unit 27 are individually connected to the control circuit 26.

FIG. 5 is a flow chart showing the operation of the second embodiment. The operation of this embodiment will be described below with reference to this figure. In the state where the photographing is not performed, the drive circuit 24 applies a voltage to the one electrode 13 of the digital micromirror element 10 to reflect the light flux incident from the photographing lens 21 in other reflection directions.

Such a reflected light beam is projected on the finder screen 33 through the finder side lens 32. The photographer views this projected image. When the shutter button 25a is pressed halfway (step S1), the control circuit 26 takes in the photometric value of the subject measured by the photometric unit 27 (step S2).

In accordance with this photometric value, the control means 26 reads the combination of the exposure period and the aperture value from the memory 26b (step S3). When the shutter button 26a is fully pressed (step S4), the control circuit 26 causes the diaphragm drive circuit 2 to operate.
5a is controlled to change the aperture area of the diaphragm 25 to match the above-mentioned diaphragm value (step S5). The light amount of the light flux incident from the taking lens 21 is limited by the diaphragm 25.

Further, the control circuit 26 gives the drive circuit 24 a signal for starting the exposure period. The drive circuit 24, to which this signal is applied, operates in the digital micromirror element 10
The electrode 13 and the columns 12a and 12b are made to have the same potential, and a voltage is applied to the other electrode 14 to reflect the light flux incident from the taking lens 21 in the first reflection direction.

The reflected light flux forms an optical image on the photosensitive member 23 via the lens 31 on the photosensitive member side (step S6). When the exposure period ends (step S7), the drive circuit 24 applies a voltage to one electrode 13 of the digital micromirror element 10 and the other electrode 14 and the support 1.
The light beams 2a and 12b are made to have the same potential, and the light beam incident from the taking lens 21 is reflected in the other reflection direction, whereby the light beam is diverted from the photosensitive member 23 (step S8).

In this way, photographing is performed in accordance with the aperture value and the exposure period stored in the memory 26b in advance. Also in the camera of the second embodiment, it is possible to obtain substantially the same effect as that of the first embodiment.

Further, in the camera of the second embodiment, the substrate 10a is arranged on the image forming surface of the taking lens 21, and the photosensitive member 23 and the finder side screen 33 are arranged at symmetrical image forming positions.
By arranging and, an image having the same image quality as the image formed on the photosensitive member 23 can be obtained on the finder side screen 33.

FIG. 6 is a diagram showing a third embodiment of the present invention. In the figure, the substrate 10a of the digital micromirror element 10 is arranged so as to be inclined on the optical axis of the taking lens 21.

The taking lens 21 is attached to the surface of the substrate 10a.
The photosensitive member 23 is arranged in a direction in which the optical axis of the is reflected geometrically. The digital micromirror element 10 has a drive circuit 24 for changing the inclination of an aluminum mirror 11 (not shown).
Are connected, and the control circuit 26 is connected to the drive circuit 24.

A shutter button 26a, a memory 26b and a photometric unit 27 are individually connected to the control circuit 26. Further, a black light absorbing plate 28 is arranged at a position where the light flux deviated from the photosensitive member 23 is irradiated.

FIG. 7 is a flow chart showing the operation of the third embodiment. The operation of this embodiment will be described below with reference to this figure. In a state in which no image is taken, the drive circuit 24 applies a voltage to all the electrodes 13 of the aluminum mirrors 11 of the digital micromirror element 10 to tilt the aluminum mirrors 11.

Therefore, the light beam incident from the taking lens 21 is deviated from the photosensitive member 23 and absorbed by the light absorbing plate 28. When the shutter button 26a is pressed halfway (step S1), the control circuit 26 takes in the photometric value of the subject measured by the photometric unit 27 (step S1).
2).

The control circuit 26 reads the combination of the exposure period and the aperture value from the memory 26b according to the photometric value (step S3). When the shutter button 26a is fully pressed (step S4), the control circuit 26 causes the drive circuit 24 to operate.
The signal for starting the exposure period is output to.

The driving means 24 selects the number of aluminum mirrors 11 in proportion to the attenuation ratio of the light quantity according to the read aperture value, sets these electrodes 13 and 14 at the same potential, and sets the aluminum mirrors 11 respectively. Parallel to the substrate 10a. The amount of light reflected from the taking lens 11 is limited by the number of aluminum mirrors 11 corresponding to the aperture value according to the aperture value, and is exposed on the photosensitive member 23 (step S5).

When the exposure period has elapsed (step S6),
The drive circuit 24 applies a voltage to the electrodes 13 of all the aluminum mirrors to tilt the aluminum mirrors 11 on the substrate 10a and deflects the reflected light flux from the photosensitive member (step S7).

By the above operation, photographing is performed in accordance with the aperture value and the exposure period stored in the memory 26b in advance. In this way, by adjusting the number of aluminum mirrors according to the aperture value, it is possible to realize the aperture function that limits the light amount.

Also in the camera of the third embodiment, it is possible to obtain substantially the same effect as in the first embodiment. Further, in this embodiment, various photographing effects can be obtained by selecting the aluminum mirror whose direction is changed. For example, an aluminum mirror that changes the direction (like a checkerboard pattern)
Even distribution on the substrate 10a makes it possible to limit the amount of light without changing the depth of field, unlike the ND filter (neutral density filter).

Further, by using the aluminum mirrors whose directions are changed as concentrically concentrated aluminum mirrors, the depth of field can be changed like an iris diaphragm and the light quantity can be limited.

Further, as an intermediate of these, the aluminum mirror whose direction is changed is a concentric and evenly distributed aluminum mirror, whereby the limiting amount of the light amount and the depth of field can be adjusted respectively. it can.

In order to realize such a diaphragm function, it is preferable to dispose the digital micromirror element 10 at a position close to the taking lens 21. With such a configuration, there is no unevenness in the image plane of the photosensitive member 23,
The amount of light can be limited evenly.

In the above-described embodiment, the taking lens 21, the photosensitive member side lens 31, and the finder side lens 32 may be compound lenses, or the diaphragm 25 is arranged between the compound lenses constituting the taking lens 21. But good. Further, by arranging a reflecting mirror, a prism and other optical elements in the middle of the optical system, the optical path may be bent, and the vertical and horizontal directions of the image may be changed.

Further, in the above embodiment, the memory 7b
For example, a read only memory (ROM), a read / write memory (RAM) or a programmable read only memory (PROM) can be used. Further, since any storage medium may be used, for example, a magnetic storage medium or an optical storage medium can be used.

The photometric method in the above embodiment is
A photometric device independent of the camera may be used, a light receiving window may be provided outside the camera to perform photometry, or TTL photometry may be used. Further, in the above-described embodiment, several kinds of combinations of the aperture value and the exposure period stored in the memory 7b are prepared,
The photographer may select them to adjust the depth of field or subject blur, or the exposure may be corrected by changing the aperture value or the exposure period according to the photographer's intention.

Further, the photographer sets either the aperture value or the exposure period, and the other value is read from the memory 7b and set according to the photometric value, whereby the aperture priority exposure or shutter speed priority exposure is performed. You may go.

Further, the light-shielding member driving means covers the photosensitive member 23 with an openable / closable light-shielding member to open the path of the incident light beam of the light-shielding member before starting the exposure period and closes the path of the incident light beam after the end of the exposure period. May be provided. With such a configuration, it is possible to prevent the photosensitive member 23 from being exposed to stray light for a long time. Further, since the light shielding member driving means may be a low speed and low precision driving mechanism, it can be simply realized.

[0085]

As described above, in the camera of claim 1, since the shutter function is realized by changing the reflection direction of the luminous flux, the conventional quick return mirror,
The movable parts such as the front curtain, the rear curtain, and the lens shutter are omitted, and the shutter mechanism is simplified. In addition, a high-speed shutter can be realized by omitting the moving part that requires these driving times. Therefore, the number of combinations of the exposure period and the aperture value is increased, and the range of photographing conditions that can obtain proper exposure is expanded.

Further, unlike the conventional case, a movable part such as a quick return mirror, a front curtain, a rear curtain or a lens shutter is not required, and a control mechanism for these movable parts can be omitted. Further, the vibration of the camera, which is mainly caused by these movable parts, can be reduced.

In the camera of claim 2, since the digital micromirror element is used as the spatial light modulator,
Since the mass of the moving part is extremely small and the displacement is small,
The shutter speed can be further increased. Therefore, the number of combinations of the exposure period and the aperture value can be increased to widen the range of shooting conditions.

Further, the shutter driving means can be composed of, for example, a switch circuit for switching the applied voltage and a delay circuit for detecting the passage of the exposure time, and the shutter control mechanism can be simplified.

Since the movable part has a small mass, vibrations at the time of starting and braking the shutter are small, camera shake is prevented, and a photograph with high sharpness can be taken. According to the camera of the third aspect, in the camera using the spatial light modulation element in the shutter mechanism, it is possible to take an image in accordance with the aperture value and the exposure period which are appropriately determined according to the actual measurement value of the subject brightness.

In the camera of the fourth aspect, both the diaphragm function and the shutter function can be realized by the digital micromirror element. Therefore, the conventional diaphragm mechanism becomes unnecessary, and the weight and cost of the camera can be reduced.

According to the fifth aspect of the present invention, the distribution of the mirrors that expose the photosensitive member is made concentric so that the amount of light irradiated on the photosensitive member and the depth of field can be adjusted. Therefore, the conventional iris diaphragm mechanism is not required, and the weight and cost of the camera can be reduced.

According to the sixth aspect of the present invention, by making the distribution of the mirrors that expose the photosensitive member uniform, it is possible to adjust the amount of light applied to the photosensitive member without changing the depth of field. it can. Therefore, a mechanism for limiting the amount of light, such as the conventional ND filter, becomes unnecessary, and the weight and cost of the camera can be reduced.

As described above, in the camera to which the present invention is applied, it is possible to obtain a proper exposure over a wide range of photographing conditions by the high-speed shutter while simplifying the shutter mechanism to reduce the weight and cost of the camera.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a digital micromirror element.

FIG. 3 is a flowchart showing the operation of the first embodiment.

FIG. 4 is a diagram showing a second embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of the second embodiment.

FIG. 6 is a diagram showing a third embodiment of the present invention.

FIG. 7 is a flowchart showing the operation of the third embodiment.

FIG. 8 is a diagram showing a conventional camera.

[Explanation of symbols]

 10 Digital Micro Mirror Element 10a Substrate 11 Aluminum Mirrors 12a, 12b Supports 13, 14 Electrode 21 Photographing Lens 23 Photosensitive Member 24 Drive Circuit 25 Aperture 25a Aperture Drive Circuit 26 Control Circuit 26a Shutter Button 26b Memory 27 Photometer 28 Light Absorption Plate 31 Photosensitive Material side lens 32 Finder side lens 33 Finder side screen

Claims (6)

[Claims] 1. A taking lens (21) for forming an optical image of a subject, and an optical flux which is arranged on the optical axis of the taking lens (21), reflects the incident light flux from the taking lens (21), and reflects the reflected light flux. A spatial light modulation element whose direction is changeable between a first direction and another direction, a photosensitive member (23) arranged in the first direction, and a photosensitive member (23) arranged in the taking lens (21), and A diaphragm (25) in which the area of the opening through which the light flux passes is variable, and the direction of the reflected light flux is set to the first direction only during the exposure period of the photosensitive member (23), and other than the exposure period. And a drive means (24) for changing the direction. 2. The spatial light modulator is a substrate (10a).
The camera according to claim 1, wherein the camera is a digital micromirror element (10) in which a plurality of mirrors (11) are arranged on the surface of the lens in a variable tilt manner. 3. A storage unit (2) that stores a combination of a predetermined exposure period and aperture value according to subject brightness.
6b), a measuring means (27) for measuring the subject brightness, and a combination of the exposure period and the aperture value is read from the storage means (26b) according to the subject brightness measured by the measuring means (27), Also, an exposure control unit (26) that sets the read exposure period to the exposure period in the driving unit (24), and the aperture (25) according to the aperture value read by the exposure control unit (26). The camera according to claim 1 or 2, further comprising: diaphragm driving means (25a) for changing the area of the opening of the camera. 4. A photographing lens (21) for forming an optical image of a subject, and a substrate (10a) tilted with respect to the optical axis of the photographing lens (21).
, And a digital micromirror element (10) in which a plurality of mirrors (11) are arranged with variable tilt, and the optical axis of the taking lens (21) is geometrically specularly reflected on the upper surface of the substrate (10a). With respect to the photosensitive member (23) arranged in the first direction and the predetermined exposure period and aperture value, only the mirror predetermined according to the aperture value is provided during the exposure period. A camera comprising: a drive unit (24) for directing the reflected light flux in the first direction and for causing the reflected light flux of all mirrors to be in the other direction except during the exposure period. 5. The predetermined mirror is a substrate (10).
The camera according to claim 4, wherein the cameras are distributed in a concentric shape on the surface of a). 6. The predetermined mirror is a substrate (10).
Camera according to claim 4, characterized in that it is evenly distributed on the surface of a).