JPH09138458A - In-finder display device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reasonably display a focus frame by selecting which light out of the first invisible light and the second invisible light an irradiation part is made to emit. SOLUTION: This device is provided with finder optical systems 6 to 8 for observing a field, the irradiation parts 9A and 9B which can respectively irradiate specified areas, a display part 6 arranged among the optical systems 6 to 8 and an irradiation selection part 15 for selecting which light out of the first visible light and the second visible light the irradiation parts 9A and 9B are made to emit. By the selection part 15, a first display pattern or a second display pattern can be displayed on a finder image plane without bleeding by the emission of the light. Besides, the plural kinds of patterns can be displayed according to the request of a photographer. Therefore, the focus frame for displaying the focus detection area of the camera can be reasonably displayed by applying the display pattern to the focus frame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera finder display device for displaying a focus detection area and the like in a camera finder.

[0002]

2. Description of the Related Art Conventionally, a focus frame for displaying a focus detection area is provided on a viewfinder screen of a camera. The focus frame is generally
It is displayed on the viewfinder screen by a broken line. However, since such a focus frame displays a specific pattern by absorbing light, when the subject is dark, there is no difference in brightness between the focus frame and the subject, which makes it difficult to see the focus frame. There was a flaw.

In order to eliminate such a defect, it is known that the pattern of the focus frame is made to emit light.
This is a display pattern of a focus frame formed on a screen by a microprism or the like, and the focus prism is displayed as a light emission pattern in the finder by irradiating the microprism or the like with light from the outside of the finder.

[0004]

However, in the above-described conventional in-viewfinder display device of a camera, light scattering or polarization characteristics due to the screen mat also exist in a portion other than the focus frame portion, so that a viewfinder screen other than the focus frame is displayed. In some cases, some or all of the colors were bleeding and were observed in a color different from the original color. Here, it is conceivable to irradiate the light only in the vicinity of the focus frame, but in order to do so, a complicated optical system is required, and there is a problem that the device becomes large and the cost further increases.

For this reason, there has been proposed a display in which a focus frame is displayed with a fluorescent material that emits visible light by ultraviolet light. Since ultraviolet light is invisible in the visible region, the finder screen is not bleeding and observed, and only the focus frame can be luminescently displayed on the finder screen. An object of the present invention is to apply this technique to display a focus frame more rationally.

[0006]

In order to solve the above-mentioned problems, the invention of claim 1 provides a finder optical system for observing an object field, a first invisible light having a first wavelength, Alternatively, the second invisible light having a second wavelength different from the first wavelength is disposed in the finder optical system and the irradiation unit capable of irradiating the second region with the second invisible light, and by irradiation with the first invisible light. A first display member that visually emits a first display pattern and a second display member that visually emits a second display pattern by irradiation of the second invisible light.
And a radiation selection unit for selecting whether the radiation unit radiates the first invisible light or the second invisible light.

According to a second aspect of the present invention, in the finder display device of the camera according to the first aspect, the light source of the irradiation section is used in common with the light source of the other irradiation section of the camera. To do. According to a third aspect of the present invention, in the viewfinder display device of the camera according to the first or second aspect, among the light incident on the display unit from a portion other than the irradiation unit, the first display member or the second display member. The display member is provided with a light emission prevention unit that removes a component that allows the display member to emit light.

According to a fourth aspect of the present invention, in the finder display device of the camera according to any one of the first to third aspects, the photometric unit for measuring the brightness of the field area and the photometric unit are used. An irradiation control unit that controls irradiation of the first invisible light or the second invisible light by the irradiation unit based on a photometric result. Claim 5
In the finder display device of the camera according to any one of claims 1 to 4, the invention of claim 1 is characterized in that the first display member or the second display member of the display unit detects focus of the camera. It is characterized by displaying an area.

[0009]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a display device in a viewfinder of a camera according to the present invention. In FIG. 1, the camera includes a camera body 1 and
It is composed of an interchangeable lens 2. In the camera body 1, a main mirror 4, a sub-mirror 5, a finder optical system (6, 7, 8), a light source 9 (9A, 9B),
Focus detection device 10 (10A, 10B) and photometric device 11
A control device 12, a shutter 13, a selection operation member 15 and the like are provided. Also, in the interchangeable lens 2,
A photographing optical system 3 is provided.

The main mirror 4 is formed with a half mirror. The viewfinder optical system has a screen 6
And a pentaprism 7 and an eyepiece lens 8. The finder optical system is for observing an image taken in from the photographing optical system 3 as a finder image. The focus detection device 10 is a device that detects a focus state at a predetermined position on the shooting screen. The photometric device 11 is a device that detects the brightness of a subject image. The light source 9 is a device that emits light to the subject in order to assist the focus detection operation of the focus detection device 10 when the brightness of the subject image detected by the photometric device 11 is low. Control device 1
A device 2 controls various operations in the camera. The selection operation member 15 is for manually selecting the focus detection area, and is electrically connected to the control device 12.

At the time of non-photographing, a part of the light flux passes through the photographing optical system 3 and is reflected by the main mirror 4. This light flux forms a subject image on the screen 6. This subject image is scattered on the screen 6 and then observed as a finder image through the pentaprism 7 and the eyepiece 8. The photometric device 11 receives the light scattered by the screen 6, calculates the brightness of the subject image, and sends it to the control device 12. Further, a part of the light flux passes through the main mirror 4 and is deflected downward by the sub mirror 5, and the focus detection device 1 is opened from the opening formed in the bottom surface 14 of the mirror box.
Guided to 0. The focus detection device 10 sends to the control device 12 a focus signal according to the focus adjustment state of the photographing optical system 3 at a predetermined position on the photographing screen. The control device 12 controls the light source 9 when the brightness obtained from the photometric device 11 is below a predetermined value.
To emit light to illuminate the subject with light for assisting the focus detection apparatus 10.

At the time of shooting, the main mirror 4 and the sub-mirror 5 are flipped up in the direction of the screen 6 and retracted from the shooting optical path. Then, the shutter 13 opens.
A film is arranged on the planned focal plane behind the shutter 13, and a subject image is exposed on this film.

FIG. 2 is a view showing the display of the focus frame F displayed on the finder screen M. As shown in FIG. On the viewfinder screen M, two focus frames FA
, FB are provided. FIG. 3 is a sectional view showing the screen 6 and the light source 9 in detail. Groove portions NA and NB corresponding to the focus frames FA and FB, respectively, are formed on the upper surface of the screen 6. The fluorescent material X is filled in these groove portions NA and NB. The fluorescent material X absorbs ultraviolet rays and emits visible light (visible light).
Is a substance that emits light. Examples of the fluorescent material X include zinc sulfide and cadmium zinc sulfide. A transparent resin or glass is provided in a region on the upper surface of the screen 6 which covers the fluorescent material X. The transparent resin or glass is used to shield the fluorescent material X from the outside air in order to prevent the fluorescent material X from deteriorating. Further, the filter 50 is provided on the screen 6 so as to cover the fluorescent material X.
A and 50B are provided. On the other hand, the light sources 9A and 9B
Are lamps 90A and 90B and a lens 92, respectively.
A and 92B. Further, filters 60A and 60B are provided between the light sources 9A and 9B and the screen 6.

FIG. 4 is a graph showing the spectral characteristics of the fluorescent material X. In the figure, a characteristic A is an excitation wavelength characteristic of the fluorescent material X, and has a characteristic that excitation is caused by ultraviolet light having a wavelength shorter than the visible light region (400 nm or less). The characteristic B is the emission wavelength characteristic of the fluorescent material X, and has a characteristic of emitting light in the visible light region. Characteristic C is a relative luminous efficiency characteristic,
The visible wavelength range of light is shown. FIG. 5 is a graph showing the spectral characteristic D of the lamp 90 (90A and 90B) and the spectral transmission characteristic G of the filters 21 and 22 (FIG. 1). The lamp 90 emits ultraviolet light, visible light, and infrared light. Further, the filters 21 and 22 have a characteristic of blocking an ultraviolet light component having a wavelength of 400 nm or less. Therefore, the filter 21 blocks the ultraviolet light incident from the photographing optical system 3. Further, the filter 22 blocks the ultraviolet light incident from the eyepiece. This prevents ultraviolet light from entering the screen 6 from the photographing optical system 3 side and the eyepiece side.

FIG. 6 is a graph showing the spectral transmission characteristics of the filters 50A and 50B. In FIG. 6, the filter 5
0A and 50B have spectral transmission characteristics TA and TB, respectively. The filter 50A has a wavelength of about 300 to 40.
It has the property of blocking ultraviolet light in the range of 0 nm. Also,
The filter 50B has a characteristic of blocking ultraviolet light having a wavelength of about 300 nm or less.

FIG. 7 is a graph showing the spectral transmission characteristics of the filters 60A and 60B. In FIG. 7, the filter 6
0A and 60B have spectral transmission characteristics SA and SB, respectively. The wavelength of the filter 60A is about 200 to 30.
It has the property of transmitting only ultraviolet light in the range of 0 nm.
The wavelength of the filter 60B is about 300 to 400 nm.
It has the property of transmitting only ultraviolet light in the range. In the wavelength region of ultraviolet light, the spectral transmission characteristic SA is substantially the same as the above-mentioned spectral transmission characteristic TA, and the spectral transmission characteristic SB is substantially the same as the above-mentioned spectral transmission characteristic TB. Furthermore, the spectral transmission characteristics SA and SB are set so as not to (substantially) overlap each other in the wavelength region of ultraviolet light. The above-mentioned spectral transmission characteristics TA and TB
The relationship is the same.

The description returns to FIG. Lamps 90A, 90B
Is turned on and off by the control device 12 (FIG. 1). Light fluxes from the lamps 90A and 90B are reflected by the lenses 92A and 92B.
The light passes through B and the filters 60A and 60B and is irradiated onto the screen 6. Further, of the light radiated on the screen 6, only the light transmitted through the filters 50A and 50B reaches the fluorescent material X below it. Therefore, when the light is emitted from the lamp 90A, the wavelength is about 200 to 300n.
Only the ultraviolet light in the range of m is transmitted through the filter 60A, and this light is transmitted through only the filter 50A.
0B is not transparent. As a result, when the lamp 90A emits light, the fluorescent material X corresponding to the focus frame FA
Only the fluorescent material X corresponding to the focus frame FB does not emit light.

Similarly, when light is emitted from the lamp 90B, only ultraviolet light having a wavelength in the range of about 300 to 400 nm passes through the filter 60B, and this light is further filtered by the filter 5B.
Only 0B is transmitted, and the filter 50A is not transmitted. As a result, when the lamp 90B emits light, only the fluorescent material X corresponding to the focus frame FB emits light, and the fluorescent material X corresponding to the focus frame FA does not emit light. The control device 12 controls which of the lamps 90A and 90B emits light according to switching of the selection operation member 15. Therefore, the photographer manually switches the selection operation member 15 to select one of the focus frames FA
Alternatively, FB can be made to emit light.

The light source 9A, 9B is used for the screen 6
When not illuminating, the color of the fluorescent material X itself is observed as the color of the focus frames FA and FB.
In a normal state, the incident light from the eyepiece side is small and the light from the photographing optical system 3 side is blocked, so that the focus frames FA and FB appear almost black.

FIG. 8 is a flow chart showing an embodiment of the operation of the present invention. First, S (step) 200
In, when the shutter release button is half-pressed, the operation process is started. In S210, the photometric device 1
The luminance detected by 1 (photometric luminance) is compared with a predetermined luminance. When the photometric brightness is higher than the predetermined brightness (when the field is bright), the process proceeds to S230, and when the photometric brightness is not higher than the predetermined brightness (when the field is dark), S22.
Go to 0. In S230, the emission of the light source 9 is prohibited and S2
In step S220, the light source 9 is allowed to emit light and the process proceeds to step S40.
Proceed to 240. In S240, it is determined whether or not the first focus detection area (FA) is selected by the selection operation member 15, and if selected, the process proceeds to S250, and if not selected, the process proceeds to S350.

In S250, it is determined whether or not the light emission is permitted. When the light emission is not permitted, the process proceeds to S280, and when the light emission is permitted, the first lamp 90A is emitted in S260 (focus frame FA is After the second lamp 90B is turned off in S270, the process proceeds to S280. In S280, the focus detection operation is performed in the first focus detection area. And S
Proceed to 400. On the other hand, when proceeding from S240 to S350,
It is determined whether or not the light emission is permitted. If the light emission is not permitted, the process proceeds to S380, and if the light emission is permitted, the second lamp 90B is illuminated (the focus frame FB is illuminated and displayed) in S360. S370
After the first lamp 90A is turned off at, the process proceeds to S380.
In S380, the focus detection operation is performed in the second focus detection area. Then, the process proceeds to S400.

In S400, the focus detection device 10A or 1
The operation according to the focus detection result of 0B (for example, the automatic focusing operation of the photographing optical system by the lens driving device and the display by the focus display device) is performed, and the process returns to S240. With the above operation, when the field is dark at the start of the operation, the selection operation member 1
The focus frames FA and FB corresponding to the focus detection area set by 5 are displayed in a light emitting manner.

In this flow, from S400 to S
You may make it return to 210. In this way, since the brightness determination is performed every time, even if the brightness changes during shooting, the light emission display of the focus frames FA and FB can be turned on / off correspondingly. In this case, in S200, the light emission is prohibited and the lamps 90A and 90B are turned off.

As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications as described below are possible within an equivalent range. (1) In FIG. 1, the filter 21 may be integrally formed on the lower surface side of the screen 6, and the effect of the filter 21 may be added to the spectral reflection characteristics of the main mirror 4. Further, when the photographing optical system 3 itself has a characteristic of blocking ultraviolet light, the filter 21 can be omitted. (2) In the present embodiment, the light source that emits the auxiliary light for focus detection and the light source that causes the focus frames FA and FB to emit light are used together, so that the cost can be reduced. Further, since the emission conditions of the auxiliary light and the emission conditions of the focus frames FA and FB are substantially the same (low brightness), the operation is simple and the emission energy can be effectively utilized. Besides, it can also be used as a red-eye preventing lamp at the time of flash photography, an illuminating means for external liquid crystal display of a camera, an illuminating means for night operation of an external operation member, and the like.

(3) The type of light source is a lamp 90
Not limited to A and 90B, an LED that emits ultraviolet light, a laser, an electroluminescent light source, or the like can be used. When the emission spectral characteristics of the light sources 9A and 9B do not include visible light, the filters 60A and 60B are unnecessary, and the cost can be reduced. (4) In the present embodiment, the fluorescent material X absorbs ultraviolet light and emits visible light, but is shorter than the optical wavelength (infrared light) absorbed by the optical nonlinear effect (generation of high- and long-waves of light). In the case of a fluorescent material that emits light of a wavelength (visible light),
An infrared light source (one that emits light having a wavelength longer than visible light) can be used. In this case, the wavelength of the infrared light is preferably 700 nm or more, but if it is 650 nm or more, the relative luminous efficiency is low, and therefore almost the same effect as that of the present embodiment can be obtained.

(5) When the fluorescent material X emits light having a wavelength different from that of excitation light excited by light in the visible light region, a light source having an extremely narrow emission wavelength region is used on the side of the light sources 9A and 9B, By using a narrow bandpass filter, the wavelength range of the light from the light sources 9A and 9B is narrowed, and the characteristics of the filters 21 and 22 are blocked only in the narrow wavelength range as opposed to the bandpass filter. It is possible to prevent the light in the narrow wavelength range from being observed on the viewfinder. (6) The use of the phosphorescent fluorescent material has an advantage that the focus frames FA and FB can be confirmed for a while even when the power is turned off.

(7) When the fluorescent material X is made to emit light, it may be made to emit light only at the start and end of focus detection (at the time of focusing). By doing so, it is possible to prevent the consumption of the battery. For example, the focus frames FA and FB may be made to emit light by pressing the release button halfway, and the focus frames FA and FB may be turned off when the release button is opened. (8) In the embodiment, the light source 9 is provided above the pentaprism 7.
Is arranged and the screen 6 is irradiated with light from this position, but the light source 9 is not necessarily limited to this position.

(9) When the screen 6 cannot be directly irradiated with light from the light source 9, the light source 9 is arranged at an appropriate position on the camera body, and a light beam is guided from that position to the screen 6 by a light guide such as an optical fiber. Just irradiate. (10) When it is desired to adjust the colors of the focus frames FA and FB at the time of light emission, the member for sealing the fluorescent material X on the screen 6 may have a bandpass filter characteristic according to the display color. (11) In the embodiment, the focus frames FA and FB
Although the example in which the focus detection area is displayed has been described above, other than this, a light measurement area, a screen size at the time of panoramic photography, and various kinds of information of the camera may be displayed.

(12) In FIG. 3, the side surfaces and bottom surfaces of the grooves NA and NB formed in the screen 6 may be provided with a light shielding property. If formed in this way, since light does not diffuse, the focus frames FA and FB can be displayed more clearly. (13) If a diffusing matte surface is formed on the lower surface of the screen 6, the light emitted from the fluorescent material X will not be diffused on the matte surface, and bleeding of the focus frames FA and FB can be prevented. (14) The groove portions NA and NB formed on the screen 6 are
It may be formed on the lower surface side of the screen 6. Alternatively, the screen 6 may be formed by stacking two members and the fluorescent material X may be disposed between the two members. By doing so, the degree of sealing of the fluorescent material X with respect to the outside air is enhanced, and the deterioration of the fluorescent material X can be prevented more reliably.

(15) In the embodiment, the display patterns of the focus frames FA and FB are formed on the screen 6, but if they are near the primary image plane, they may be on the lower surface of the pentaprism 7 or the filter 21. good. (16) The light receiving element of the photometric device 11 is arranged so that the light receiving element of the photometric device 11 is not affected by the ultraviolet light from the light source 9.
It is desirable to protect with an ultraviolet light cut filter.

(17) In the embodiment, the focus frames FA and FB are made to emit light when the field is dark. However, for example, when the focus frames FA and FB are difficult to see due to the fine pattern of the subject. It is also possible to control so that it emits light. For example,
A high frequency component is extracted from the image sensor used in the focus detection device 10. If the high frequency component is more than a predetermined amount, it is determined that the subject is a fine pattern and the focus frames FA and FB are caused to emit light. To do.
In this case, since the subject brightness is relatively high, the photometric device 1
When the subject is bright, the focus frame F is controlled by controlling the light emission power of the ultraviolet light source in accordance with the brightness detected by 1.
Increase the emission intensity of A and FB. By doing so, the focus frames FA and FB can be easily seen even when the subject is bright.

(18) In order to reduce energy consumption due to irradiation from the ultraviolet light source, for example, the ultraviolet light source is made to emit light for a certain period of time when the release button is activated when the shutter button is fully pressed to start the photographing operation and when the shutter button is half pressed. Alternatively, the ultraviolet light source may be caused to emit light for a certain period of time when the focus detection device 10 detects the in-focus state. (19) Fluorescent material X that is transparent in the non-light emitting state
It is also possible to completely obscure the display pattern when the ultraviolet light source for excitation is turned off by forming on the screen 6 by vapor deposition or the like. By doing so, when the display of the focus frames FA and FB is unnecessary, the focus frames FA and FB can be completely erased and the subject image can be seen clearly.

(20) In the embodiment, the filters 60A and 60B are used to generate ultraviolet light having different wavelengths. However, a plurality of LEDs or the like capable of emitting light having different emission spectral characteristics are used as light sources. You may use. If the filter is formed in this way and the filters 60A and 60B are not used, a smaller space and a lower cost are obtained. (21) Although the same fluorescent material X is used for the two focus frames FA and FB, different fluorescent materials X having different excitation characteristics and emission characteristics may be used. If the light is emitted in different colors, the visibility of the focus frames FA and FB is improved. Further, the same fluorescent material X may be used so that the emission colors of the focus frames FA and FB are different.

[0034]

According to the first aspect of the present invention, the first display pattern or the second display pattern can be luminescently displayed by the irradiation selection section without causing bleeding on the finder screen. Further, it is possible to display a plurality of types of patterns in response to a photographer's request. According to the invention of claim 2,
Since the light source of the irradiation unit is shared with other light sources, it is possible to emit the display pattern without increasing the cost.

According to the third aspect of the present invention, since the component of the external light that causes the display pattern to emit light is removed by the light emission prevention unit, it is possible to prevent the display pattern from emitting light by light other than the irradiation unit. it can. According to the invention of claim 4, since the light emission of the display pattern is controlled according to the brightness of the scene, it is possible to make the display pattern easy to see according to the brightness of the scene. According to the invention of claim 5, since the display pattern is applied to the focus frame for displaying the focus detection area of the camera, the focus frame can be rationally displayed.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a display device in a viewfinder of a camera according to the present invention.

2 is a diagram showing a display of a focus frame F displayed on a finder screen M. FIG.

FIG. 3 is a sectional view showing a screen 6 and a light source 9 in detail.

FIG. 4 is a graph showing spectral characteristics of fluorescent material X.

5 is a spectral characteristic D of a lamp 90 (90A and 90B) and a spectral transmission characteristic G of filters 21 and 22 (FIG. 1).
It is a graph which shows.

FIG. 6 is a graph showing spectral transmission characteristics of filters 50A and 50B.

FIG. 7 is a graph showing spectral transmission characteristics of filters 60A and 60B.

FIG. 8 is a flowchart showing an embodiment of the operation of the present invention.

[Explanation of symbols]

 1 Camera body 2 Interchangeable lens 3 Photographing optical system 6 Screen 7 Penta prism 8 Eyepiece 9 Light source 15 Selection operation member 21, 22 Filter 60 Filter

Claims (5)

[Claims] 1. A finder optical system for observing a field and a first invisible light having a first wavelength or a second invisible light having a second wavelength different from the first wavelength. An irradiation unit capable of irradiating a predetermined area, a first display member disposed in the finder optical system, which illuminates a first display pattern by irradiation of the first invisible light, and the first display member. A display unit having a second display member that visually emits a second display pattern by irradiating the second invisible light; and the irradiation unit irradiates the first invisible light or the second invisible light. An in-viewfinder display device of a camera, comprising: an irradiation selection unit for selecting whether to perform. 2. The display device in a viewfinder of a camera according to claim 1, wherein the light source of the irradiation unit is used in common with the light source of another irradiation unit of the camera. Display device. 3. The display device in the viewfinder of the camera according to claim 1, wherein the first display member or the second display is included in light entering the display unit from a portion other than the irradiation unit. An in-viewfinder display device for a camera, comprising: a light emission prevention unit that removes a component that causes a member to emit light. 4. The viewfinder display device of the camera according to claim 1, wherein a photometry unit that measures the brightness of a field region and a photometry result by the photometry unit are used. And an irradiation control unit that controls the irradiation of the first invisible light or the second invisible light by the irradiation unit. 5. The in-viewfinder display device of the camera according to claim 1, wherein the first display member or the second display member of the display unit is a focal point of the camera. A display device in a viewfinder of a camera, which displays a detection area.