JP2001194577A - Structure for range-finding window of camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent erroneous range-finding caused by leaked light emitted or made incident from an end face where a window member arranged on the front of a light projecting part or a light receiving part is exposed. SOLUTION: This structure for the range-finding widow of the camera is equipped with a slide type slide cover 4 for opening/closing the front of a photographing lens 15 provided on the front of a camera body 3, and provided with the light projecting part 7 projecting range-finding light to a subject outside the moving area of the cover 4 and the light receiving part 8 receiving the range-finding light reflected from the subject inside the moving area of the cover 4. In such structure, the end faces where the window member 9 covering over the front of the light projecting part 7 and made transmissive to the range- finding light and the window member 10 covering over the front of the light receiving part 8 and made transmissive to the range-finding light are made to face are exposed and the end face 9a of the member 9 on the light projecting part 1 side is coated with pigment opaque to the range-finding light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring window structure of a photographic camera or a digital camera having an active distance measuring device.

[0002]

2. Description of the Related Art In an active distance measuring apparatus frequently used in a camera, distance measuring light is projected from a light projecting section toward a subject, and the distance measuring light reflected by the object is received by a light receiving section. The light receiving unit incorporates a light receiving element that photoelectrically detects the incident position of the ranging light, and calculates the subject distance based on the incident position. Therefore, if disturbance light enters the light receiving unit, it causes erroneous distance measurement. Therefore, light in the near-infrared region used as distance measuring light is transmitted through the front of the light receiving unit, and light in other wavelength ranges such as visible light is transmitted. It is usual to arrange a window member that blocks the light. This window member also has a function of preventing the light receiving unit from dust and dirt, and for the same reason, a window member is also provided on the front surface of the light receiving unit. When the distance between the light-emitting portion and the light-receiving portion is relatively small, these window members are integrated, and when they are apart from each other, they are fitted into individual window frames. It is surrounded by an inner wall.

On the other hand, a compact camera in which most of the camera body is covered by a slide case is known from Japanese Patent Application Laid-Open No. Hei 11-231391. The camera described in this publication is devised so that a step is not formed at the boundary between the slide case and the camera body when the slide case is closed, and one of its features is compactness without unevenness when the camera is carried. In use, by opening the slide case, the photographing lens incorporated in the camera body, the light emitting section for distance measurement, and the light receiving section are exposed on the front. These front surfaces are covered by the above-mentioned window members, and these window members are fitted into window frame-shaped openings in the front wall of the camera body.

[0004] It is known that the base line length can be increased in order to further improve the distance measuring accuracy of a camera distance measuring device. Therefore, in the above-described camera with a slide case, if it is desired to keep the light emitting part and the light receiving part as far as possible while maintaining their compactness, it is more advantageous to separate the light emitting part and the light receiving part in the horizontal direction than in the vertical direction. Therefore, it is preferable to incorporate one of the window members into a position not covered by the slide cover and incorporate the other into the moving range of the slide case. Accordingly, one window member is provided at a position not covered by the slide case, and the other window member is provided at a position opened and closed by the slide case or the slide case.

[0005]

However, for example, when the light projecting portion is installed at a position not covered by the slide case and the window member is to be mounted on the front surface thereof, the end surface of the window member is reduced in order to make the camera compact. In some cases, a window frame that surrounds all cannot be used, and one end face of the window frame must be exposed at the boundary with the slide case. When such a structure is used, a part of the distance measurement light projected from the light projecting unit may be repeatedly reflected from the inner surface by the window member and emitted from the end surface to reach the light receiving unit or the front window member. . When such leaked light is incident on the light receiving element inside the light receiving unit, the subject distance cannot be calculated accurately, causing erroneous distance measurement.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and in order to make the camera compact and reduce the number of parts, the end face of a window member arranged in front of the light projecting portion or the light receiving portion is provided with a window frame. It is an object of the present invention to provide a distance measuring window structure in which erroneous distance measurement is not performed due to leakage light emitted or incident from an end face of the distance measuring window when it cannot be surrounded by the above.

[0007]

According to the present invention, in order to attain the above object, an end face of a window member disposed in front of a light emitting or light receiving section for distance measurement is exposed toward the other window member. In the case of a structure, an opaque pigment for the distance measuring light is applied to the end face thereof, so that erroneous distance measurement due to light leaking from the end face can be prevented without using a separate component. The present invention is particularly suitable for use in a camera that includes a lens cover that opens and closes the front surface of a photographic lens, and that has an end face of a window member exposed at the joint between the camera body and the lens cover. As the lens cover, not only a slide case for slidingly opening and closing most of the camera body as described in the above publication, but also a cover for partially opening and closing only the front surface of the camera body may be used.

[0008]

FIG. 1 shows the appearance of a camera with a slide case using the present invention. A box-shaped slide case 4 is provided on the camera body 3 and is opened as shown in the figure when used. When the slide case 4 is opened, the strobe light emitting unit 16 pops up from the camera body 3 and the power switch is turned on. As a result, the lens barrel 6 in which the photographing lens 15 is incorporated is exposed to the front, and at the same time, protrudes from the retracted position to the photographing position shown in the figure, and the photometric window 19 for measuring the luminance of the subject is exposed.

When the slide case 4 is slid, the shutter button 18 provided on the upper surface is locked to the camera body 3 when the shutter button 18 reaches a predetermined operation position.
The operation of the shutter button 18 is validated. Further, since the slide case 4 is also used as a grip, even if the camera body 3 is miniaturized, the gripping property at the time of photographing is not impaired. By operating the knob 17, the slide case 4 can be further pulled out, whereby the cartridge loading chamber is exposed on the bottom surface of the camera, so that the film cartridge can be taken out and loaded.

The slide case 4 is made of a thin metal plate using a titanium alloy or an aluminum alloy. In accordance with this, outside the moving range of the slide case 4, the exterior cover 5 made of the same kind of thin metal plate is provided on the surface of the camera body 3.
Is covered. When the slide case 4 is closed after the strobe light emitting unit 16 is popped down and the lens barrel 15 is retracted, the entire camera has a compact shape with no protruding portion on the outer surface.
Are joined in series without a step, and a sense of unity between the slide case 4 and the outer cover 5 can be obtained.

As shown in FIGS. 2 and 3, a camera body 3 has a light projecting section 7 comprising an LED 7a for emitting near-infrared light and a light projecting lens 7b, and a light receiving element for discriminating an incident position of distance measuring light. A light receiving section 8 including a light receiving lens 8b and a light receiving lens 8b is incorporated. The light projecting section 7 is provided outside the moving range of the slide case 4, and the light receiving section 8 is provided within the moving range of the slide case 4. A window member 9 is fixed to the exterior cover 5 of the camera body 3 so as to cover the front surface of the light emitting unit 7. Also, the light receiving section 8
Is fixed to the slide case 4, and the window member 10 is located on the front surface of the light receiving section 8 when the slide case 4 is opened.

The window members 9 and 10 are each made of a plastic thin plate, and a filter layer 9c on which a pigment that transmits distance measuring light in the near infrared region and blocks visible light is printed is formed on the back surface side. ing. Thus, the light projecting unit 7 and the light receiving unit 8 do not appear in the appearance, and they do not become dirty due to the entry of dust. The window member 9 on the side of the light projecting unit 7 is provided with a finder window 9b transparent to visible light. This can be easily dealt with by determining the print pattern of the filter layer 9c so as to remove the finder window 9b. Since the finder window 9b is located in front of the finder objective lens 14 incorporated adjacent to the light projecting unit 7, there is no problem in finder observation.

Since the exterior cover 5 is made of a thin metal plate, as shown in FIG. 3, the window member 9 covering the front surface of the light projecting section 7 is fixed to the exterior cover 5 from the back side with an adhesive or the like. Of the end surfaces of the window member 9, other than the end surface 9 a serving as a joint with the slide case 4 can be covered with a window frame 5 a protruding from the camera body 3, but the end surface 9 a is aligned with the slide case 4. Since it becomes an eye, it cannot be framed and is exposed toward the light receiving section 8 side. On the end face 9a, a light-shielding layer 13 formed by printing or applying a pigment that blocks distance measuring light is formed. In addition, it is also possible to provide a similar light shielding layer 13 on the other end face of the window member 9,
In that case, it is not always necessary to provide the window frame 5a on the camera body side.

A window member 10 covering the front surface of the light receiving section 8 is similarly fixed to the back surface of the slide case 4 with an adhesive or the like. Since the window member 10 moves with the movement of the slide case 4, each end face is exposed. As described above, when the light shielding layer 13 is provided on the end surface 9a of the window member 9 on the light emitting side, the light shielding layer 13 that is opaque to distance measurement light is not necessarily provided on each end surface of the window member 10. However, when the light shielding layer 13 is provided on each of them, the window member 9 on the light emitting side is provided.
It is also possible to omit the light-shielding layer 13 from the end face 9a.

The operation of the present invention will be described below. When the shutter button 18 is pressed halfway from the state shown in FIG. 1, distance measuring light is emitted from the light emitting unit 7 toward the subject. The distance measuring light reflected from the object enters the window member 10 covering the front surface of the light receiving unit, and the distance measuring light enters the light receiving element 8a at a position corresponding to the object distance through the light receiving lens 8b. The photographing lens 15 based on the signal from the light receiving element 8a
Is moved in the optical axis direction by driving the focus motor, and focusing is performed. In addition, when the subject brightness is
The shutter speed and the aperture are automatically determined according to the luminance of the subject. When the shutter button 18 is fully depressed, shooting is performed under the determined shutter speed and aperture. At this time, when the subject brightness is below a predetermined level, the flash light is automatically emitted from the strobe light emitting unit 16 toward the subject. Is irradiated.

When the distance measuring light is projected from the light projecting section 7 toward the subject, a part thereof is repeatedly reflected on the inner surface of the window member 9 and reaches the end face 9a exposed toward the light receiving section 8 side. From there it tries to inject outside. However, since the light-shielding layer 13 that is opaque to the distance measurement light is applied to the end face 9a, it is possible to reliably prevent the distance measurement light from being emitted toward the light receiving section 8 and to perform accurate measurement. It becomes possible to perform distance.

Therefore, the end face 9a does not have to be covered with the window frame 5a on the camera body 3 side and further with other parts, and can be left exposed as a mating face with the slide case 4. This is advantageous in reducing the number of parts and reducing the size of the entire camera.
Furthermore, when the slide case 4 is closed, the open side end face of the slide case 4 can be brought into close contact with the end face with the exterior cover 5, so that the appearance design when carrying can be neatly organized.

Although the present invention has been described with reference to the illustrated embodiment, the present invention is not limited to the camera having the slide case 4 as described above, but also includes a window member for covering the front surface of the light projecting unit or the light receiving unit. It is equally applicable to cameras that have to expose the end face. Further, instead of the light-shielding layer 13, a light-shielding sheet having a similar function can be adhered to the end face, but application by printing is also suitable for improving work efficiency.

[0019]

As described above, according to the present invention, a pigment that does not transmit the distance measuring light is applied to the end face of the window member provided on the front surface of the light projecting portion or the light receiving portion for distance measuring, and the window member is used to apply the pigment. A part of the internally measured reflected distance measuring light is prevented from leaking to the outside, or the distance measuring light leaking from the light emitting part is prevented from entering as external light from the end face of the window member on the light receiving part side. The distance measuring performance can be stably maintained without covering the end face of the member with another component.

[Brief description of the drawings]

FIG. 1 is a perspective view when a slide camera embodying the present invention is used.

FIG. 2 is an enlarged exploded view of a distance measuring mechanism of the slide camera shown in FIG.

FIG. 3 is a sectional view of a distance measuring mechanism of the slide camera shown in FIGS. 1 and 2;

[Explanation of symbols]

 Reference Signs List 2 camera 3 camera body 4 slide cover 5 exterior cover 5a window frame 7 light emitting part 7a LED 7b light emitting lens 8 light receiving part 8a light receiving element 8b light receiving lens 9, 10 window member 9a end face 9b finder window part 9c filter layer 13 light shielding layer 14 Viewfinder objective lens

Claims (2)

[Claims] 1. An individual window transparent to the distance measuring light in front of a light projecting unit for projecting distance measuring light toward a subject and a light receiving unit receiving the distance measuring light reflected from the subject. In a distance measuring window structure of a camera in which members are provided and at least one window member has an end face exposed toward the other window member, a pigment opaque to distance measuring light is provided on an end face of the one window member. A ranging window structure for a camera, characterized in that a coating is applied. 2. A light-emitting unit having a slide-type lens cover for opening and closing the front surface of a taking lens, and projecting distance-measuring light toward a subject, and a light-receiving unit for receiving distance-measuring light reflected from the subject. Is provided outside the movement range of the lens cover,
The other is a ranging window structure of a camera provided in a movement area of a lens cover, wherein an end surface of a window member which covers the one front surface and is transparent to distance measurement light is exposed at a joint with the lens cover, and the end surface thereof is provided. A ranging window structure for a camera, characterized in that an opaque pigment is applied to the ranging light.