JPH0350497Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a mirror device for a single-lens reflex camera, in particular, a first mirror structure that swings from a viewfinder observation position to a shooting retreat position, and It relates to having a second mirror configuration that swings relative to the configuration.

(Prior art) In recent years, a first mirror that partially transmits light is provided so as to be able to rotate from a viewfinder observation position to a photography retreat position, and the light transmitted from the first mirror at the viewfinder observation position is used for photometry or distance measurement. Various single-lens reflex cameras have been proposed in which a second mirror that guides the light to the light receiving element is rotatably attached to the first mirror.

Conventionally, methods for determining the rotational position of the second mirror in this type of single-lens reflex camera are disclosed in Japanese Patent Application Laid-open Nos. 54-115130 and 1982-33634.
As shown in No. 1, the second mirror is biased by a spring in the opening direction relative to the first mirror, and the second mirror is always slid against the camera body by the spring bias in the opening direction. By forming a cam surface and sliding a second mirror on this cam surface, the opening angle of the second mirror at the finder observation position of the first mirror and the forced closing rotation at the photographing retreat position are performed. things are known. However, as is well known, extremely high precision is required for the swinging position of each mirror of the camera, and as in the conventional proposal mentioned above, both the open and closed positions of the second mirror can be controlled by one cam surface. When positioning, it becomes difficult to adjust for component errors and installation position errors. In other words, if the cam surface is adjusted, for example, to match the open position of the second mirror, a position error will occur at the closed position, and in turn, when adjusted to the closed position, an error will occur at the open position. This results in the following problems. Therefore, in order to actually adjust the above-mentioned positions accurately, it is necessary to add a complicated mechanism, and the adjustment process also becomes a time-consuming process. .

In addition, in the above-mentioned conventional proposal, when the first mirror turns a little further than the predetermined position due to inertia during the final turning process toward the shooting retreat position, the second mirror is also turned in the closing direction more than necessary due to the cam surface. Unauthorized power (commonly known as tsutsupari power) on the other side works,
Problems such as deformation of the second mirror occur.
In order to prevent this problem from occurring, a more complicated additional configuration is required, which has an impact on cost and space.

On the other hand, other methods include JP-A No. 56-109331, JP-A-58-100335, JP-A-56-83737,
No. 57-51942, Utility Model Application No. 57-112333, etc. have been proposed. This method uses a toggle mechanism to switch the spring biasing direction of the second mirror from midway through the swinging of the first mirror. It is configured to work in a direction to close the second mirror, and conversely to work in a direction to open it from the middle of swinging toward the viewfinder observation position. In order to position the second mirror according to this proposal, it is only necessary to control the opening position in the viewfinder observation state using a pin provided on the camera body, and otherwise, when the first mirror swings in both directions, the position of the second mirror is adjusted. It is necessary to provide a mechanism for following the opening and closing of the mirror to a predetermined position.

However, in the above-mentioned proposal, since the biasing direction of the second mirror is switched during opening and closing, there is a problem that the movement becomes jerky at this switching position.

Furthermore, in the above proposal, the biasing spring of the second mirror needs to be attached to the camera body, and the process of assembling the mirror device into the camera body and then locking the spring to the second mirror is necessary. is required, which causes problems regarding workability.

Furthermore, in the above-mentioned proposal, since it is necessary to configure the urging spring as a torgue mechanism, a long-legged spring must be used as the spring, which is inefficient in terms of space and causes problems when downsizing the camera body. It will end up being put away.

(Summary of the invention) The present invention was devised in view of the above-mentioned conventional problems, and improves the positioning accuracy of the second mirror configuration, and also improves the irregularity given to the closing direction of the second mirror configuration. It solves problems such as deformation by preventing the generation of force (commonly known as tsutsupari force), improves workability and space efficiency, and also allows the mirror configuration to swing to the shooting retracted state at an early stage. An object of the present invention is to provide a mirror device for a single-lens reflex camera.

In order to achieve the above object, the present invention includes a first mirror structure that is swingable between a viewfinder observation position and a photographing retreat position, and a swinging fulcrum on the first mirror structure. , a single-lens reflex camera having a second mirror configuration that is swingably provided, and a biasing means that biases the second mirror configuration in a closing direction with respect to the first mirror configuration. In the mirror device, a pin is formed on one of the second mirror configuration or the camera body, and a first contact portion and a second contact portion are formed on the other side so as to sandwich the pin, and the first contact portion On the movement trajectory of the mirror configuration from the photographing retracted position to the viewfinder observation position, the pin contacts the first contact portion and causes the second mirror configuration to resist the biasing means. On the other hand, on the movement locus of the first mirror configuration as it swings from the viewfinder observation position to the photography retreat position, the pin abuts the second contact part. The present invention is characterized by a mirror device for a single-lens reflex camera in which the second mirror structure is forcibly swung in a closing direction.

(Embodiment) FIGS. 1 and 2 are side views of a mirror device according to an embodiment of the present invention, viewed from the left and right, respectively, and FIGS. 3 and 4 are operational diagrams of the mirror device of the embodiment.

In the figure, 1 is a semi-transparent area 1 that reflects the light incident from the photographing lens in the direction of the finder optical system in the finder observation state of Figure 1.
a first mirror that is partially or totally transmitted by a and splits into light directed toward the finder screen 17 and the light-receiving element 21; 2 is an arm portion that holds the first mirror 1 and has an opening 2c through which the semi-transparent light from the semi-transparent region 1a passes, and in which shafts 7, 8, etc., which are the center of rotation of the first mirror 1, are implanted; A first mirror holding frame in which 2a and 2b are fixed with caulking pins 14 and 15. Note that in FIGS. 1 and 3, the arm portion 2b is omitted to avoid complicating the drawings. Reference numeral 3 denotes a second total reflection mirror that reflects the semi-transmitted light from the first mirror 1 and guides it to the light receiving optical systems 20 and 21.
mirror. Reference numeral 4 denotes a second mirror holding frame which is rotatably suspended around shafts 12 and 13 implanted in the first mirror holding frame 2, and this holding frame 4 has a first leg portion 4a and a second leg portion 4a. A foot portion 4b is formed.
Reference numerals 7 and 8 are axes that serve as the center of rotation of the first mirror holding frame 2, and are implanted in the arm portions 2a and 2b.
9 is an eccentrically adjustable pin that positions the viewfinder observation position of the first mirror holding frame 2;
When the holding frame 2 is urged to rotate counterclockwise by a pin 10 implanted in the arm portion 2b by a spring (not shown), the holding frame 2 comes into contact with the pin 9 and is positioned;
By adjusting the rotation of this pin 9, the position of the first mirror 1 can be adjusted. Reference numeral 11 denotes a spring that biases the second mirror holding frame 4 in the closing direction with respect to the first mirror holding frame 2, and is supported by a shaft 13 and has one end locked to the second mirror holding frame 4 and the other end. is in contact with pin 10. 14 and 15 are caulking pins. Reference numeral 16 denotes an eccentrically adjustable pin formed on the camera body, which forcibly opens the second mirror 3 in the viewfinder observation state by coming into contact with the first foot 4a of the second mirror holding frame 4. In addition to determining the position, the second
It comes into contact with the second foot 4b in order to close the mirror holding frame 4 quickly. 17 is a focusing plate holder 18
A focus plate held in a. Reference numeral 19 denotes an elastic member that regulates the photographing retreat position of the mirror device, and specifically, it is arranged at a position where it comes into contact with the tip of the first mirror holding frame 2. Reference numeral 20 denotes a condensing lens constituting, for example, a photometric optical system, which condenses the semi-transmitted light onto the light receiving element 21.

The mirror device of this embodiment has the above configuration,
Next, the operation will be explained.

First, the raising operation of the mirror device, that is, the operation from the viewfinder observation position to the photographing retreat position will be explained.

The pin 10 is raised by a first mirror lifting means (not shown).
When the first mirror holding frame 2 starts to rise (clockwise), the second mirror holding frame 2 moves to the position shown in FIG. 3a.
The foot portion 4b of is in contact with the pin 16. This is because the rising speed of the first mirror holding frame 2 is generally fast, so even though the second mirror holding frame 4 is biased by the spring in the closing direction, the second leg portion 4b does not reach the pin 1.
6 and starts pushing the second mirror holding frame 4 in the closing direction to speed up the transition to the photographing retracted state. Then, as the mirror device rises, the third
As shown in FIG. 3B, the second mirror holding frame 4 is further pushed in the closing direction, and as shown in FIG. 3C, the first mirror holding frame 2 is completely raised and the elastic member 19 This continues until the rotation reaches the position where it makes contact with the Thereafter, as shown in FIG. 3d, the second mirror holding frame 4 continues to rotate in the closing direction only by the spring biasing force, and as shown in FIG. 3e, the second mirror holding frame 4 continues to rotate in the closing direction. The shutters are closed almost completely overlapping each other, and the movement to the photographing retreat position is completed.

In addition, in the above-mentioned final operation, the second mirror holding frame 4 is properly closed with respect to the first mirror holding frame 2 by the spring 11, so that the reverse incident light from the finder optical system is allowed to enter the film surface. There is no. Further, even if the first mirror frame 2 crushes the elastic member 19 due to inertia force and rotates more than necessary, no force in the closing direction is applied to the second mirror holding frame 4 more than necessary. The deformation caused by illegal force, which was a problem in the above, does not occur.

In addition, the reason why the second mirror holding frame 4 is forcibly pushed in the closing direction by the pin 16 when moving from the viewfinder observation position to the photographing retreat position described above has the effect of increasing the transition speed as described above. During this operation, the first leg portion 4a and the focusing plate holder 18
It is also possible to obtain the effect of preventing fraud.

Next, the lowering operation of the mirror device, that is, the operation from the photographing retreat position to the viewfinder observation position will be explained.

FIG. 4a shows the initial state in which the first mirror holding frame 2 is lowered (counterclockwise), and the second mirror holding frame 4 is moved by the contact between the pin 16 and the first leg 4a. It is pushed and rotated in the opening direction. Further, this second mirror holding frame 4 is shown in FIG.
As shown in FIG. 4c, it rotates in the opening direction until it reaches the state shown in FIG. 1, that is, the first mirror holding frame 2 comes into contact with the pin 9 and reaches the viewfinder observation position.
The second mirror holding frame 4 continues to rotate in the opening direction. Therefore, the position of the second mirror holding frame 4 in the viewfinder observation state is substantially determined by the position of the pin 16.

Note that the first mirror 1 in the viewfinder observation state
The position can be easily adjusted by rotating the pin 9 that positions the first mirror holding frame 2, and furthermore, the position of the second mirror 3 in the same state can be adjusted by adjusting the position of the second mirror holding frame 4. pin 1
This can be easily done by adjusting the rotation of 6.

In the above-described embodiment, the first and second mirror holding frames 2 and 4 are configured to rotate, but the same effect can also be obtained by swinging them using a link mechanism.

(Effects of the invention) As explained above, the present invention biases the second mirror configuration in the closing direction, and the open position of the second mirror configuration is determined by the contact between the first contact portion and the pin. The closing position of the second mirror configuration is thus determined, and the closing position of the second mirror configuration is biased until completely closed by the biasing means, so that the position of the second mirror configuration in the closing direction does not require adjustment, and the closing position of the second mirror configuration is determined in the opening direction. The positions of can be independently adjusted, and the position accuracy can be improved very easily. Furthermore, from the above, even if the first mirror structure swings a little more than the predetermined position due to inertia during the final swinging process toward the shooting retreat position, there will be no illegitimate force on the second mirror structure. Problems such as deformation will not occur without any additional deformation, and no additional configuration to prevent this deformation is required.

Also, from the above, the closing swing of the second mirror structure is caused by the movement of the pin and the second abutting part, even if the first mirror structure swings to the photographing retracted position quickly and cannot be followed by the spring force alone. Since it is pushed by the contact, it is possible to quickly reach the photographing retreat position, and it is also possible to prevent unauthorized contact with the focusing plate holder. or,
Furthermore, from the above, since the biasing means for biasing the second mirror configuration in the closing direction can be installed before the mirror device is assembled into the camera body,
It is possible to provide a mirror device for a single-lens reflex camera that is improved in workability, does not require a particularly large space, improves space efficiency, and does not adversely affect downsizing of the camera body.

[Brief explanation of the drawing]

FIG. 1 is a side view of a mirror device as an embodiment of the present invention. FIG. 2 is the other side view of FIG. 1. 3 and 4 are explanatory diagrams showing the operation of the mirror device of FIG. 1. 1...First mirror, 2...First mirror support frame,
3...Second mirror, 4...Second mirror holding frame, 4
a...first foot part (first contact part), 4b...second
foot portion (second contact portion), 9...pin, 11...spring, 16...pin.

Claims (1)

[Claims for Utility Model Registration] A first mirror structure that is provided to be swingable between a viewfinder observation position and a photography retreat position, and a swinging fulcrum on the first mirror structure, In a mirror device for a single-lens reflex camera, the mirror device includes a second mirror configuration that is movably provided, and biasing means that biases the second mirror configuration in a closing direction with respect to the first mirror configuration. , a pin is formed on one of the second mirror configuration or the camera body, and a first contact portion and a second contact portion are formed on the other side so as to sandwich the pin, and the first mirror configuration On a movement trajectory during the swing from the photographing retracted position to the viewfinder observation position, the pin abuts the first contact portion and opens the second mirror configuration against the biasing means. On the other hand, on the movement trajectory of the first mirror configuration from the viewfinder observation position to the photography retreat position, the pin comes into contact with the second contact portion and is forced to move. A mirror device for a single-lens reflex camera, characterized in that the second mirror structure is swung in a closing direction.