JPH04278932A - Camera - Google Patents

Abstract

PURPOSE:To prevent a mirror from coming into contact with a photographing lens by enabling the photographing lens to be moved to a lens housing position from a photographing prepared position only when it is detected that the mirror is present in a retracting position. CONSTITUTION:In a photographing unprepared state, the photographing lens 6 is retracted to the lens housing position in the vicinity of an aperture in a camera main body. At this time, the mirror 20 is held at the mirror retracting position at an upper part or the side part of the lens housing position. In a photographing prepared state, the lens 6 advances to the forward photographing preparing position from the lens housing position and the mirror 20 enters simultaneously the lens housing position from the retracting position. Then, only when the mirror 20 is present on the retracting position, the lens 6 is controlled so as to be allowed to enter the lens housing position in order to prevent the lens 6 and the mirror 20 from coming into contact with each other.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly, it has an optical system structure configured to guide a light beam passing through a photographing optical system to a finder optical system, and
The present invention relates to a so-called collapsible camera in which a photographing lens is retracted into the camera body when not photographing.

0002

2. Description of the Related Art Current still cameras compatible with silver halide film can be roughly divided into cameras with interchangeable lenses and cameras with non-interchangeable lenses.

A typical example of the former is a single-lens reflex camera that has a so-called TTL optical system configured to obtain a light flux to a finder optical system and a light flux for photometry through a photographing optical system, and a typical example of the latter is a single-lens reflex camera that has a so-called TTL optical system. This is a so-called compact camera in which the finder optical system and photographic optical system are completely separated.

[0004] Ever since the introduction of single-lens reflex cameras, compact cameras have been designed to be inexpensive, small, lightweight, and easy to handle even for amateurs. While a lens shutter that could be used for multiple purposes was adopted, and electronic control of various operations was promoted to simplify operations, there were no plans to upgrade the basic functions of the camera.

[0005] Recently, however, with the increasing demand for compact cameras, development aimed at increasing the functionality of compact cameras has begun, and as a result, today, among the compact cameras on the market, Many models have become so-called zoom cameras with zoom lenses.

As described above, it is expected that the development trend of providing non-interchangeable lens cameras with functions similar to those of single-lens reflex cameras will continue. In order to have the same functionality as a reflex camera, it is necessary to change the basic design of conventional compact cameras. For example, in conventional compact cameras, the shooting optical system was a non-zoom lens with constant magnification, so the parallax between the shooting optical system and the finder optical system was negligible.However, as the shooting magnification increases, parallax also increases. Therefore, if a zoom lens is used as the photographing optical system in a conventional compact camera, the parallax value becomes large enough to not be ignored, and from this point on, it is no longer possible to follow the structure of the conventional optical system. In addition, cameras with zoom lenses need to be able to accurately measure the distance to distant objects, but it is difficult to measure distances with the active distance measuring devices used in current compact cameras. It will be necessary to change to a conventional distance measuring device. Therefore, it can be said that it is desirable to adopt the same TTL system as the current single-lens reflex camera for the structure of the optical system of the camera. Note that non-interchangeable lens cameras designed based on this basic concept are already on the market.

[0007]

[Problems to be Solved by the Invention] In a camera having a TTL optical system, a movable mirror is essential for guiding the light beam to the finder optical system. Since it must be provided at the rear, it is unavoidable that the length of the lens barrel that protrudes forward of the camera body increases. Therefore, a conventional camera equipped with a conventional TTL optical system and a zoom lens has a problem in that the camera becomes large.

The object of the present invention is to solve the above-mentioned problems and provide a more compact camera.

[0009]

[Means for Solving the Problems] In the camera of the present invention, the photographing lens is moved back to a lens storage position near the aperture in the camera body when it is not ready for shooting, and at that time, the mirror is moved above or to the side of the lens storage position. The mirror is held at the retracted position on the left side, and in the photographing preparation state, the photographing lens moves forward from the lens storage position to the photographing preparation position in front, and the mirror enters the lens storage position from the retracted position. It has become. In order to prevent the photographic lens from coming into contact with the mirror, the control system is configured to allow the photographic lens to enter the lens storage position only when it is detected that the mirror is in the retracted position.

0010

[Operation] As shown in FIG. 1, in the camera of the present invention, the photographing lens 6 can be retracted to the lens storage position below the mirror 20 only when it is detected that the mirror 20 is in the retracted position. Therefore, there is no fear that the photographing lens 6 and the mirror 20 will come into contact with each other, and the lens 6 can be retracted to the lens housing position within the camera body, making it possible to downsize the camera.

[0011]

[Embodiments] Examples of the present invention will be described below with reference to the drawings. 1 to 6 are diagrams showing a first embodiment of the present invention. In FIGS. 1 to 3, 1 is a camera body, 2 is a photographic film, 3 is a first lens group of a photographic optical system, and 4 is a first lens group. 2 lens groups, 5 a third lens group, and 6 a fourth lens group.

Reference numeral 7 denotes a fixed cylinder fixed to the main body 1, which includes a straight groove 7a (see FIG. 4) that restricts the rotation of a zoom cam ring 14 and a second group cylinder 16, which will be described later, and a parallel groove that releases the rotation restriction of the zoom cam ring 14. 7b (see FIG. 4) is formed. 8
is a collapsible cam ring rotatably held on the fixed cylinder 7, and is shown in Fig. 4.
As shown in , a zoom cam groove 8b for driving the zoom cam ring, a second group cam groove 8c for driving the second group cylinder 16, and a parallel cam groove 8d are formed, and an internal gear 8a is provided inside the end thereof. ing. 9 is a motor, and a reduction mechanism 1
The driving force reduced at 0 is transmitted to the output gear 11 to drive the internal gear 8a that meshes with the output gear 11.

14 is a zoom cam ring, which connects the first group cylinders 15 and 3.
A zoom groove (not shown) is formed to drive the group barrel 17, and as shown in FIG. is maintained. Reference numeral 15 denotes a first group cylinder that holds the first lens group 3, and as shown in FIG. Reference numeral 16 denotes a second group cylinder that holds the second lens group, and as shown in FIG. 4, a pin 16a fixed to the outer periphery is fitted and held in the grooves of the collapsible cam ring 8 and the fixed cylinder 7. Reference numeral 17 denotes a third group cylinder that holds the third lens group 5, and a pin 17a fixed to the outer periphery is fitted and held in a groove of the zoom cam ring 14. 18 is the 4th group cylinder that holds the 4th lens group, and the 4th group main plate 1
9 and is configured to perform a focusing operation by an AF mechanism (not shown). 19 is the 4th group main plate,
It is attached to the first group cylinder 15.

Reference numeral 20 denotes a mirror, which is rotatably held in the main body 1 about an axis 20a, and has a dowel 20b fixed to its side surface. A condenser lens 21, a pentaprism 22, and an eyepiece 23 constitute a known finder system. In the figure, 24 is a shutter blade, SH
(Shutter) Driven by a drive mechanism 25. Reference numeral 26 denotes a mirror up detection switch, which is composed of sections 27 and 28. Reference numeral 29 denotes a mirror down detection switch, which is composed of sections 30 and 31.

Reference numeral 32 denotes a mirror drive motor, and a pinion gear 33 is fixed to the rotating shaft. 34 is a reduction gear,
It is attached to the main body 1 so as to be rotatable about a shaft 34a, and has a large gear part 34b and a small gear part 34c that mesh with the pinion gear 33. A cam gear 35 is rotatably attached to the main body 1 about a shaft 35a, and has a gear portion 35c that meshes with the small gear portion 34c of the reduction gear 34 and a cam portion 35b. 36 is a transmission lever, which is connected to shaft 3.
It is rotatably supported by the main body 1 about a center 6a, and has arms 36b and 36c extending in two directions.A spring 38 is hung on the arm 36b, and the arm 36c is in contact with the aforementioned cam portion 35b. 37 is a fan-shaped sector lever held coaxially with the transmission lever 36, and has a gear portion 37a and an arm 37b.
A spring 38 is hung on the tab portion 37c. The spring 38 is a spring that connects the transmission lever 36 and the sector lever 37, and maintains the state in which the arms 36b and 37b are in contact with each other. Reference numeral 39 denotes a drive lever that is slidably attached to the main body 1 through an elongated hole 39a, and has a rack portion 39b on the side surface that engages with the gear portion 37a of the sector lever 37, and a slit 39c at the tip of the drive lever that engages with the gear portion 37a of the sector lever 37. The dowel 20a is sandwiched between the dowels 20a and is biased downward in the figure by a spring 40 hung on the arm 39d.

FIG. 5 is a block diagram schematically showing the control system of the camera of this embodiment. 41 is C that controls camera operation
PU (i.e. microcomputer). 42 is the main switch of the camera, SWO. 43 is a mirror drive circuit that controls the mirror drive motor 32; 44 is a collapsible barrel drive circuit that controls the motor 9. 45 is an encoder detection circuit composed of a pulse sheet 12 and a photointerrupter 13, which detects the amount of rotation of the motor 9. 46 is SH (shutter)
In the drive circuit, the shutter blade 2 is driven by the SH drive mechanism 25.
Drive 4. 47 is a switch SW1 that is turned on when the release button is pressed halfway, and 48 is a switch SW2 that is turned on when the release button is pressed further.

With the above configuration, the operation of this embodiment will be explained with reference to the flowchart shown in FIG.

When the camera is not in operation, it is in the state shown in FIG. 1, and the main switch 42 (SW0) is in a standby state. When SW0 is turned on, the microcomputer 41 starts up, and first,
At the same time as the encoder detection circuit 45 is activated, the collapsible barrel drive circuit 44 is activated to energize the motor 9 and drive the collapsible cam ring 8. Then, the collapsible cam ring 8 starts rotating, and the zoom cam ring 14 is moved through the pins 14a and 16a.
Then, the second group barrel 16 is extended toward the subject. Figure 4(a), (
b) shows this situation, and when the collapsible cam ring 8 starts rotating in the direction of arrow A, the pins 14a and 16a are regulated by the straight groove 7a, so the cam groove 8b moves as shown in FIG.
, 8c to move toward the subject (to the left in the figure). Therefore, the first group cylinder, third group cylinder, and fourth group cylinder held by the zoom cam ring 8 also move in the same way and are driven to the wide position (states shown in FIGS. 1 and 4(c)). When the wide position is detected, the power to the motor is cut off, the collapsible cam ring 8 stops, and the photographic lens enters the wide state. The wide position is detected, for example, by counting the number of pulses detected by the encoder detection circuit 45, and when a predetermined number of pulses is counted, the motor 9 is stopped and the collapsing drive circuit 44 is stopped. Next, when the mirror drive circuit 43 is activated and the mirror drive motor 32 is energized, the cam gear 35 rotates clockwise via the reduction gear 34.

By the way, the drive lever 39 is biased downward in the figure by the biasing force of a spring 40, and is connected by a sector lever 37 which is gear-coupled to the drive lever and is spring-coupled coaxially with the sector lever. The transmission lever 36 is biased clockwise, and the arm portion 36c comes into contact with the large diameter portion of the cam portion 35c of the cam gear 35 and stops. When the cam gear 35 rotates clockwise and the contact of the arm portion 36c shifts from the large diameter portion of the cam portion 35c to the small diameter portion, the spring 40
The transmission lever 36 and the sector lever 37 are
rotates clockwise and the drive lever 39 moves downward. Then, the dowel 20b of the mirror 20 is also moved downward by the slot 39c, so the mirror 20 rotates around the mirror 20a and finally reaches the mirror lowered state shown in FIG. 3. At this time, the tip of the mirror 20 pushes the section 30 and the section 31
When the mirror down switch 29 is brought into contact with the mirror down switch 29, the mirror down switch 29 is turned on.

When the microcomputer 41 detects the lowered state of the mirror, the mirror drive motor 32 is stopped and the mirror drive circuit 43 is stopped, but this state is detected by an encoder (not shown) to detect the mirror drive motor 32 and stop the mirror drive circuit 43. 3
This is done by counting the number of drive pulses. here,
The microcomputer 41 checks the state of the mirror down switch 29, and if it is not in the ON state, the mirror 20 is not lowered and is in an abnormal state, so it sets the camera to prohibition mode, and if it is in the ON state, it proceeds to the next operation and switches the SH The drive circuit 46 is activated. Then, the shutter blade 24 is opened by the SH drive mechanism, and the subject light passes through the photographic lens, is reflected by the mirror 20, and is guided to the finder system, allowing the photographer to observe the subject image, and the camera is ready to take pictures. Become. In this state, the mirror is shielded from light by the mirror 20 and the main body mirror box (not shown) so that the subject light does not reach the photographic film 2.

A photographing operation is performed when the photographer presses the release button from the above-mentioned photographing ready state, but the contents thereof are not directly related to the intention of the present invention and will therefore be briefly explained below. When SW1 is turned on, the camera performs photometry and distance measurement, and focuses based on the distance measurement information.
s operation is performed. Next, when SW2 is turned on, a release operation is performed, first the shutter blade is closed and the mirror is raised, and then the shutter blade is opened and closed again based on the photometry information to achieve proper exposure, and then the mirror is lowered and the shutter is released. The blade opening is performed and the release operation is completed.

Next, an explanation will be given of the operation when the photographer performs a zoom operation to change the photographing angle of view in the photographing enabled state described above. When the zoom button (not shown) is operated, the motor 9
energization is carried out, and the collapsible cam ring 8 is driven again. That is, in the wide state shown in FIG. 4(c), the collapsible cam ring 8 is further driven in the direction of arrow A. Since the pin 16a is located in the area of the parallel cam groove 8d, even if the collapsible cam ring 8 rotates, the pin 16a does not move as shown in FIG. 4(d), that is, the second group cylinder 16 remains unchanged. keep. Also, pin 14
Since the restriction by the straight groove 7a is released and the point a is located in the area of the parallel groove 7b, it moves in the same direction as the arrow A as shown in FIG. 4(d). In other words, the zoom cam ring 14 is
Rotate while staying in the wide position shown in . Then, the pin 1 fitted and held in the cam groove of the zoom cam ring 14
5a and 17a, the first group cylinder 15 and third group cylinder 17 are driven, but since the rotation of the first group cylinder 15 and third group cylinder 17 is restricted by the aforementioned second group cylinder, the zoom cam ring 8 It is extended linearly along the cam groove to perform a zoom operation.

The following operation is a zoom operation, and the movement from wide to Tele was explained, but from Tele to Wi
The movement in the de direction is performed by energizing the motor 9 in the opposite direction to that described above, resulting in a similar operation.

Next, the operation of putting the camera into a non-use state will be explained with reference to FIGS. 2 and 3. First, in FIG. 3, when the main switch 42 (see FIG. 5) is turned off, the microcomputer 41 operates the SH drive circuit 46, and the SH drive mechanism 25 drives the shutter blade 24 to close it. After the closure of the shutter blade is detected by a known switch means or the like, the SH drive circuit 46 is stopped. Next, when the mirror drive circuit 43 is activated and the mirror drive motor 32 is energized, the cam gear 35 rotates clockwise via the reduction gear 34, and the large diameter portion of the cam portion 35c engages the arm 36c of the transmission lever 36. Push up to rotate the transmission lever 36 counterclockwise in FIG.

Since the sector lever 37 is connected to the transmission lever 36 by a spring 38, it similarly rotates counterclockwise so that the gear part 37a moves the drive lever 39 via the rack part 39b of the drive lever 39 to the spring 40. Push it upwards in the figure against the Then, the dowel 20b of the mirror 20 is also pushed upward by the slotted portion 39c, so that the mirror 20
The mirror rotates around 20a and finally reaches the mirror raised state shown in FIG. At this time, the tip of the mirror 20 becomes the section 28.
is pressed to bring it into contact with the section 29, and the mirror up switch 26 is turned on. Similarly to the mirror lowering operation described above, an encoder (not shown) counts the number of drive pulses of the mirror drive motor 32, and when it is detected that the drive required to raise the mirror has been performed, the mirror drive motor 32 is stopped and the mirror is driven. Circuit 43 stops.

Here, the microcomputer 41 checks the state of the mirror up switch 26, and if it is in the ON state, it performs the next operation, which is the collapsing operation, but if it is not in the ON state, the mirror is not in the raised state, so the collapsing operation This is prohibited to prevent the photographic lens and mirror from colliding and being destroyed. ON
If this is the case, the collapsible barrel drive circuit 44 is activated, and the motor 9 is energized in the opposite direction to the collapsible barrel delivery operation described above, thereby rotating the collapsible barrel cam ring in the opposite direction. The operation is the same as the collapsible barrel delivery described above, but the direction is reversed, and the driving amount is similarly determined by counting the number of pulses of the encoder detection circuit 45. Therefore, when a predetermined number of pulses are counted, the motor 9 is stopped, the collapsing drive circuit 44 is stopped, and at the same time, the encoder detection circuit 45 is also stopped, and the microcomputer 41 returns to the SW0 standby state.

FIGS. 7 and 8 are diagrams showing a second embodiment of the present invention, and the same reference numerals are given to the parts corresponding to those in the first embodiment described above, and explanations thereof will be omitted. do. The second embodiment is different from the first embodiment in the mirror drive mechanism configuration and detection method, and the mirror drive state is detected using a substrate and a slice having a conductive pattern.

A cam gear 50 is rotatably held in the main body 1 around a shaft 50a, has a gear portion 50b on its outer periphery that meshes with the small gear portion 34c of the reduction gear 35, and has a cam groove on its back surface. 50c is formed. Reference numeral 51 denotes a transmission lever, which is rotatably attached to the main body 1 around a shaft 51a, and has dowels 51b and 51c fixed to arms extending in two directions, a spring 38 is hung on the dowel 51b, and the dowel 51c
is inserted into the aforementioned cam groove 50c. Reference numeral 52 designates a fan-shaped sector lever, which is held coaxially with the transmission lever 51, and which holds the gear part 52a that meshes with the rack part 39b of the drive lever 39, the dowel 52b on which the spring 38 is hung, and the dowel 51b with a predetermined gap. Slip split 5
2c. Further, a substrate 53 having a conductive pattern 53a is attached to the cam gear 50, and three pieces 54, 55, and 56 are mounted on the pattern 53a.

The lifting and lowering operation of the mirror 20 in the above configuration will be explained. When the mirror drive motor 32 is energized, the cam gear 50 and the board 53 rotate clockwise via the pinion 33 and reduction gear 35. As the transmission lever 51 rotates, the dowel 51c of the transmission lever 51 is moved to the small diameter portion by the cam groove 50c, the transmission lever 51 rotates clockwise, and the sector lever 52 similarly rotates. Then, as in the first embodiment described above, the drive lever 39 is moved downward via the rack portion 39b, and the mirror 20 is also rotated counterclockwise about 20a via the dowel 20b to reach the lowered state. This state is shown in FIG. 8(b).

At this time, the pieces 55 and 56 are placed on the pattern 53 of the substrate 53, and the piece 54 is removed from the pattern 53. That is, the sections 55 and 56 are in a conductive state,
The segments 54 and 55 are in a non-conducting state. When this state is detected, the mirror drive motor 32 is stopped and the mirror lowering operation is completed. Similarly, in the mirror raising operation, when the mirror drive motor 32 is energized and the cam gear 50 is further rotated, the dowel 51c of the transmission lever 51 moves the transmission lever 51 counterclockwise as the cam groove 50c moves from the small diameter section to the large diameter section. This is accomplished by rotating. That is, in the same way as the mirror lowering operation, the sector lever 52 rotates counterclockwise, the drive lever 39 moves upward, and the mirror 20 rotates clockwise around 20a through the dowel 20b, as shown in FIG. 8(a). The mirror rises. At this time, the sections 54 and 55 are placed on the pattern of the substrate 53, and the section 56 is off. That is, the sections 54 and 55 are in a conductive state, and the sections 55 and 5 are in a conductive state.
6 is in a non-conductive state. When this state is detected, the mirror drive motor 32 is stopped and the mirror raising operation is completed.

By the way, since the dowel of the transmission lever 51 is held by the cam groove 50c, the rotational phase of the cam gear 50 and the rotational phase of the transmission lever 51 always correspond one to one. Similarly, the transmission lever 51 and the sector lever 52
have a one-to-one correspondence due to the combination of the dowel 51b and the slot 52c, the sector lever 52 and the drive lever 39 have the same correspondence due to the gear combination, and the drive lever 39 and the mirror 20 have a one-to-one correspondence due to the combination of the slot 39c and the dowel 20b. Corresponds to 1. That is, since the rotational phase of the cam gear and the rotational phase of the mirror always have a one-to-one correspondence, detecting the phase of the cam gear means detecting the phase of the mirror, that is, whether it is in the raised or lowered state. Specifically, with the intercept 55 as a common intercept,
When the section 55 is in electrical continuity with the section 54, the mirror is in the raised state, and when the sections 55 and 56 are in electrical continuity, the mirror is in the lowered state.

As is clear from the above description, in the second embodiment, the motor stop timing of the mirror raising/lowering operation and the mirror position detection are performed using the section and the conduction pattern, which is different from the above-mentioned first embodiment. This function is similar to that of the mirror up switch, mirror down switch, and motor drive pulse detection means in the example. The rest of the configuration is the same as the first embodiment, so a description of its operation will be omitted. Further, the block diagram and flowchart showing the configuration of the control system are also omitted because they are the same as in the first embodiment, with the only difference being the method of detecting the position of the mirror and the method of detecting the stop timing of the mirror drive motor.

[0033]

[Effects of the Invention] As explained above, in the camera of the present invention, the photographing lens is allowed to be moved from the photographing preparation position to the lens storage position only when it is detected that the mirror is in the retracted position. Therefore, there is no risk of contact between the mirror and the photographic lens, and therefore, according to the present invention, it is possible to realize a compact camera in which the photographic lens can be collapsed to the mirror arrangement position.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a non-photographing preparation state of a camera according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the state of the camera when photographing.

FIG. 3 is a diagram showing a state in which the camera is ready for photographing.

FIG. 4 is a diagram showing the operating state of the cam mechanism of the camera.

FIG. 5 is a schematic diagram of the control system of the camera.

FIG. 6 is a flowchart showing the operation of the control system of the camera.

FIG. 7 is a diagram showing the state of the camera according to the second embodiment of the present invention when photographing.

FIG. 8 is a diagram showing the operation of the mirror drive mechanism of the camera in FIG. 7;

[Explanation of symbols]

1; Camera body
3; first lens group 4; second lens group
5; Third lens group 6; Fourth lens group 7; Fixed barrel 8; Collapsible cam ring
8a; Internal gear 9; Motor
10; Reduction mechanism 11; Gear
12; Pulse sheet 13; Photo interrupter 14;
Zoom cam ring 15; 1st group barrel
16; 2nd group cylinder 17; 3rd group cylinder
18; 4th group cylinder 19; main plate
20;
Mirror 21; condenser lens
22; Pentaprism 23; Eyepiece
24; Shutter blade 25; Shutter drive mechanism 26;
Mirror up detection switch 29; Mirror down detection switch 32; Mirror drive motor 34; Reduction gear
35; Cam gear 36; Transmission lever
37; Sector lever 38; Spring
39; Drive lever 40; Spring 41; CPU (microcomputer) 42; Main switch 43; Mirror drive circuit 44; Collapse drive circuit
45; Encoder 46; Shutter drive circuit
50; Cam gear 51b, 51c; Dowel
52; Sector lever 52b; Dowel
52c; Slit 53a; Continuity pattern
54-56; switch section

Claims (1)

[Claims] 1. A photographing lens movable between a photographing preparation position and a lens storage position within a camera body, a retracted position away from the optical axis of the photographic lens, and a position including the lens storage position or the lens storage position. In a camera having a mirror movable between the two, and a lens driving means for moving the photographing lens between the photographing preparation position and the lens storage position, it is possible to detect when the mirror is in the retracted position. Mirror detection means for detecting the mirror, and lens movement control that allows the lens driving means to move the photographing lens from the photographing preparation position to the lens storage position only when it is detected that the mirror exists in the retracted position. A camera comprising means.