JP2786002B2 - camera - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, particularly to a single-lens reflex camera provided with a photometric device on the exit side of a pentaprism.

[Prior Art] FIG. 4 shows a general layout of a photometric device of a single-lens reflex camera. In the figure, 41 is a taking lens,
42 is a camera body, 43 is a main mirror, 44 is a reticle,
45 is a pentaprism and 46 is an eyepiece. 47 is a photometric lens, 48 is a photometric sensor, which is disposed on the exit surface side of the pentaprism near the eyepiece 46, measures the subject image formed on the focusing screen 44, and sets the desired exposure. Calculation and control are performed by a control device (not shown).

[Problem to be Solved by the Invention] However, in the configuration of the conventional example described above, the eyepiece 46
And the photometric sensor 48 will be located close to each other,
Backlight from the eyepiece 46 becomes stray light and the photometric sensor
It goes around 48, the metering value changes, and it is controlled by the wrong metering value.

To prevent this, the eyepiece 46 and photometric sensor 48
A method to prevent stray light to the photometric sensor 48 by separately providing a light blocking member between the camera and the camera may be considered.However, in order to accurately perform photometry in a predetermined area, the position of the photometric sensor 48 needs to be adjusted. If a space for securing the light is provided, there is a problem that the light-shielding effect cannot be obtained.

In addition, the photometric sensor itself is relatively weak against external noise, and there is also a problem that when a camera is used directly under a fluorescent light or the like, the photometric value fluctuates due to the influence of the electrical noise.

The present invention solves such a conventional problem, and provides a camera capable of removing optical noise and electric noise from the outside of the camera with respect to the light shielding device without adding a light shielding member or an electric shielding member. The purpose is to:

[Means for Solving the Problems] A configuration for realizing the object of the present invention is a camera in which a photometric device is arranged near an eyepiece lens on an exit surface side of a pentaprism, wherein the photometric device includes a photometric sensor. The photometric sensor and the fixed portion are connected to a front surface of the flexible printed wiring board, and are sandwiched by a pressing member having a pressing surface on at least the flexible printed wiring board side, and at least one surface of the flexible printed wiring board is subjected to the photometry. The sensor is characterized in that it is formed as a pattern area covering at least the periphery of the sensor, and a through hole formed on the wiring is provided in a holding area of the pressing surface of the pressing member.

In the above-described configuration, the area of the pattern may be
It is characterized by being formed as a GND or power supply pattern.

[Operation] In the above-described camera, the reverse light from the eyepiece is shielded from light by the pattern area covering the periphery of the photometric sensor formed on the flexible printed wiring board, and the through-hole formed on the flexible printed wiring board is pressed. Since the light is covered by the member, the reverse incident light from the eyepiece does not reach the photometric sensor through the flexible printed wiring board.

In addition, since the photometric sensor is shielded by the pattern area covering at least the periphery of the photometric sensor, the photometric sensor is not affected by external noise.

In addition, by forming the above-mentioned pattern area as a GND or a power supply pattern, the shielding effect is further ensured.

[Embodiment] FIGS. 1 and 2 show an embodiment of a camera according to the present invention. FIG. 1 is a sectional view of a central portion of the camera, and FIG.
It is the figure which looked at the photometry apparatus shown in the figure from right on the paper surface.

In FIG. 1, reference numeral 1 denotes a main mirror for guiding a light beam from a photographic lens (not shown) upward, 2 a focusing plate for forming a subject image from the photographic lens, and 3 a pentapriz, and a mirror box, respectively. 4 attached.
Reference numeral 5 denotes an eyepiece, which allows a subject image on the focusing screen 2 to be observed through the pentaprism 3. Reference numeral 6 denotes an eyepiece frame, which holds the eyepiece 5 and is fixed to the camera body 7.

On the other hand, the photometric device is located behind the pentaprism 3 and immediately above the eyepiece 5 in FIG.

The photometric lens 8 constituting the photometric device is fixed and held in a photometric lens housing 4a above the mirror box 4.
Reference numeral 9 denotes a photometric sensor having a photometric section 9a, which is connected to the flexible printed board 10 by soldering. Printed board 10
The photometric sensor 9 is fixed to the sensor housing 11a of the case 11 so that the photometric sensor 9 is sandwiched from behind the printed board 10 by the elastic force of the pressing member 12 having a U-shape. Have been. Further, the case 11 includes a photometric lens housing 4a at the top of the mirror box 4.
The case 11 is movable with respect to the mirror box 4 and is moved and adjusted by an adjustment tool (not shown) to adjust the position of the photometric sensor 9 if necessary. After performing the above, it can be fixed with screws 13.

The flexible printed wiring board 10 is a board having double-sided copper foil, and is connected to a wiring board (not shown) at a pattern lead-out portion 10a. Reference numeral 10b denotes a wiring pattern for drawing out the input and output of the photometric sensor 9, and is wired on the back side of the drawing. Ten
c (shown by oblique lines in the figure) is a copper foil (GND pattern) applied so as to cover the periphery where the photometric sensor 9 is located.
It is provided on the front side of the paper, and the surface is covered with an insulating material. Reference numeral 10d denotes a group of through holes formed for the sake of wiring, and is covered and held by the holding member 12. (14 is an upper cover, which protects the above-described components from the outside of the camera.) In the camera configured as described above, in actual photometry, the subject image formed on the reticle 2 is converted into a photometric lens 8.
Passes through the pentaprism 3 and the photometric unit of the photometric sensor 9
An image is formed on 9a and photometry is performed. On the other hand, eyepiece 5
Light L that has entered the camera from inside is blocked by the copper foil (GND or power supply pattern) provided on the flexible printed circuit board 10 disposed at the rear end of the photometer, and stray light into the photometer. Has been prevented. In the portion where the through holes 10d are arranged, there is an interval in the wiring pattern and the portion becomes a light transmitting portion.
Since d is concentrated on the portion covered and covered by the holding member 12, stray light to the inside is blocked by the holding member 12.

In addition, the photometric sensor is electrically shielded from external noise by forming the light shielding copper foil pattern with GND or a power supply pattern.

FIG. 3 is a rear view of a photometric device showing another embodiment of the camera according to the present invention. In the present embodiment, a part of the flexible printed board 10 has an exposed portion of copper foil not covered with an insulating material.
10e is provided. Then, the protruding portion 12a extending from a part of the holding member 12 is brought into contact with the copper foil exposed portion 10e. Therefore, since the copper foil pattern 10c on the flexible printed board 10 has GND or a power supply potential,
Numeral 12 becomes GND or a power supply potential via the protruding portion 12a to further enhance the electrical shielding effect.

Note that, as long as the through-hole group 10d is not concentrated, the positions and shapes of the copper foil exposed portion 10e and the protruding portion 12a are arbitrary.

[Effects of the Invention] As described above, according to the present invention, it is possible to prevent reverse light from an eyepiece from entering a photometric sensor without newly adding a light shielding member, and Since the photometric value does not change depending on the light condition of the external environment, accurate exposure control can be performed.

At the same time, the pattern area on the flexible printed wiring board provided for light shielding electrically shields at least the periphery of the photometric sensor, and thus has an effect of removing the influence of the external noise on the photometric sensor.

Furthermore, by forming the above-mentioned pattern area as a GND or a power supply pattern, the shielding effect can be further ensured.

[Brief description of the drawings]

1 and 2 are sectional views showing an embodiment of a camera according to the present invention and a view of a photometric device as viewed from the rear side of the camera. FIG. FIG. FIG. 4 is a sectional view of a conventional camera. DESCRIPTION OF SYMBOLS 1 ... Main mirror, 2 ... Focusing plate 3 ... Penta prism, 4 ... Mirror box 5 ... Eyepiece, 6 ... Eyepiece frame 7 ... Camera body, 8 ... Photometric lens 9 ... Photometric sensor , 10 ... printed board 11 ... case, 12 ... holding member 13 ... screw, 14 ... top lid

Claims (2)

(57) [Claims] 1. A camera in which a photometric device is arranged near an eyepiece lens on an exit surface side of a pentaprism, wherein the photometric device connects a photometric sensor to a front surface of a flexible printed wiring board and is fixed to the photometric sensor. And at least one portion of the flexible printed wiring board is formed as a pattern area covering at least the periphery of the photometric sensor, and a through hole formed on the wiring is formed. A camera, wherein a hole is provided in a holding area of a holding surface of the holding member. 2. The camera according to claim 1, wherein the area of the pattern is formed as a GND or a power supply pattern.