JP3416539B2 - Flange back adjustment mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera in which an image pickup device and an optical system are provided in a housing, for adjusting a distance from a mounting reference plane of a lens to a focal plane of the image pickup device, that is, a flange back. It is related to the mechanism.

[0002]

2. Description of the Related Art In a color dedicated camera, for example, as shown in FIG. 21 (a), a CCD (8
1), a protective glass (85), and an optical filter (95) for color correction are provided, and a lens unit (2) having an objective lens (21) is screwed and fixed to the housing (1). The optical filter (95) is configured by sandwiching a color correction filter plate (99) between two birefringent crystal plates (96) (97). For example, the flange back is 12.5 mm
In case of the camera, the thickness t of the optical filter (95) is 4.3.
8mm, CCD protective glass (85) is 0.75m thick
m, the distance s from the surface of the protective glass (85) to the imaging surface (focal plane) of the CCD (81) is 1.94 mm, and the lens unit (2)
The screw-in amount b of is set to 5.6 mm. in this case,
If the refractive index n of the optical filter (95) is 1.5, the elongation λ of the optical path length generated by passing through the optical filter (95) and the protective glass (85) is λ = (1-1 / n) × Since (4.38 + 0.75) = 1.71 mm, the distance a from the lens mounting reference surface A of the housing (1) to the image pickup surface of the CCD (81) is the flange back.
(12.5 mm) and the optical path length λ (1.71 mm), which is a total value of 14.21 mm.

On the other hand, in the camera shown in FIG. 21 (b), instead of the above-mentioned optical filter (95) having a sandwich structure, the two birefringent crystal plates (96) (97) bonded to each other are provided on one side. An optical filter (91) having a color correction filter film (98) formed by vapor deposition is adopted. In this camera, the thickness t ′ of the optical filter (91) is 2.78 mm, and the extension λ ′ of the optical path length caused by passing through the optical filter (91) and the protective glass (85) is λ ′ = (1-1 / n) x (2.78 + 0.75) = 1.18 m
Therefore, the distance a ′ from the lens mounting reference surface A of the housing (1) to the image pickup surface of the CCD (81) is the flange back (12.5 mm) and the optical path length extension λ ′ (1.18 mm). The total value is 13.68 mm.

A conventional camera employs a flange back adjustment mechanism as shown in FIG. 22 in order to adjust the above flange back to a predetermined value (for example, 12.5 mm). That is, the front cover that constitutes the housing
A CCD holding a CCD (not shown) on the inner surface of (200)
The holder (205) is supported so as to be reciprocally movable within a predetermined range along the optical axis, and is urged in one direction by a spring (203). Further, an eccentric pin (204) is interposed between the CCD holder (205) and the front cover (200),
By rotating the head of the eccentric pin (204) protruding from the hole (201) opened in the front cover (204) with a tool, the CCD holder (205) is moved against the spring (205), Adjust the flange back. After adjusting the flange back, the fixing screw (202) is screwed into the front cover (200), and the tip of the fixing screw (202) is pressed against the upper surface of the eccentric pin (204), whereby the eccentric pin (204) Is fixed non-rotatably and the flange back is maintained at a predetermined value.

[0005]

However, in the conventional flange-back adjusting mechanism, not only a tool is required for adjusting the flange-back, but also the amount of change in the flange-back with respect to the rotational operation amount thereof is large, so fine adjustment is required. There was a problem that is difficult. However, if the rotational operation force is weakened during the adjustment, the eccentric pin (204) reverses due to the biasing force of the spring (205), so while holding the tool for rotating the eccentric pin (204) in one hand, Use your hand to secure the fixing screw (2
It was necessary to tighten 02) with another tool, and there was a problem that the fixing operation of the flange back was extremely difficult.

An object of the present invention is to provide a flange back adjusting mechanism in which the work for adjusting and fixing the flange back is easier than in the past.

[0007]

SUMMARY OF THE INVENTION A flange back adjustment mechanism according to the present invention is a surface that surrounds an optical axis of an optical system and is orthogonal to the optical axis with respect to a housing (1) containing an image pickup device and an optical system. An adjustment ring (rotatably supported inside and having a finger hook (38) for rotation operation protruding to the outside of the housing (1) and an arc surface (36) having a center of curvature on its rotation axis ( 3)
And an image pickup device unit that has a built-in image pickup device, is supported by the housing (1) so as to be capable of reciprocating along a light axis of the optical system within a predetermined range, and is elastically biased in one direction, A cam mechanism interposed between the adjusting ring (3) and the image pickup device unit to press the image pickup device unit in a direction opposite to the elastic biasing direction as the adjustment ring (3) rotates, and a housing (1). An elastic member having a leaf spring portion (51) attached to the inside of the base and pressed against the circular arc surface (36) of the adjusting ring (3).
(5) and a lock screw (14) which penetrates the housing (1) from the outside to the inside and is screwed into the housing (1) and the tip of which protrudes toward the leaf spring portion (51) of the elastic member (5). I am. Further, a lens unit (2) having an objective lens (21) constituting the optical system is attached to the housing (1) on the optical axis.

In the flange back adjusting mechanism of the present invention, the finger ring (38) protruding from the adjusting ring (3) is operated in one direction to rotate the adjusting ring (3), which is accompanied by the rotation. The cam mechanism operates to move the image sensor unit against the elastic biasing force. This changes the flange back. Here, the cam mechanism is the adjustment ring.
Since it can be formed into a cam curve that gently changes along the circumference of (3), the amount of change in flange back with respect to the rotation of the adjusting ring (3) can be set small.
This allows fine adjustment. Also, the adjustment ring (3)
Even if the finger rest (38) is released during the rotation operation of the adjustment ring (3), the plate spring portion (51) of the elastic member (5) is pressed against the circular arc surface (36) of the adjustment ring (3) to adjust the adjustment ring. Since the frictional resistance is given to the rotation of (3), the adjusting ring (3) is not reversed by the elastic biasing force. After adjusting the flange back, screw the lock screw (14) to fix the adjusting ring (3) so that it cannot rotate. Here, the tip of the lock screw (14) locks the adjusting ring (3) by pressing the leaf spring part (51) of the elastic member (5) against the circular arc surface (36) of the adjusting ring (3). Therefore, the tip of the lock screw (14) does not bite into the adjusting ring (3), and reliable locking is realized by surface contact.

In a specific construction, the adjusting ring (3) is
Ring part rotatably supported with respect to the housing (1)
(31) and comprises a collar portion (35) protruding from the ring portion (31),
The finger rest (38) is projected on the collar portion (35) and the arc surface (36) is formed, and the cam mechanism directs the ring portion (31) of the adjusting ring (3) toward the image pickup device unit. It is composed of a formed cam surface and a cam follower formed in the image pickup device unit.

According to this specific structure, the adjusting ring (3) and the image pickup device unit can be integrally formed with the cam surface and the cam follower, which are the constituent members of the cam mechanism, and the number of parts can be reduced. Can be done.

[0011]

According to the flange back adjusting mechanism of the present invention, the flange back can be adjusted by directly operating the finger rest (38) without using a special tool, and the fine adjustment is easy. Is. Also, even if you release your hand from the finger rest (38) during the adjustment, the adjustment will not be misaligned, so you can use both hands to screw in the lock screw (14) after adjusting the flange back, The work of fixing the flange back becomes extremely easy.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a surveillance camera will be specifically described below with reference to the drawings. The surveillance camera of this embodiment sets the shooting mode to the color mode in a bright place, but can switch the shooting mode to the monochrome mode in a dark place. In the color mode, as shown in FIG. As shown, between the lens unit (2) and CCD (81)
An optical filter (91) formed by vapor-depositing a color correction filter film (98) on one surface of a birefringent crystal plate (96) (97).
And the color correction processing such as infrared ray cutoff is performed. On the other hand, in the monochrome mode, a dummy glass for optical path length correction is arranged instead of the optical filter (91) as described later. Then, of the luminance information and the color information obtained from the CCD (81), only the luminance information is used to reproduce the image.

The surveillance camera of this embodiment is shown in FIGS.
, The front cover (11) and the housing body (1
A lens unit having a metallic housing (1) consisting of 2) and an objective lens (21) on the front cover (11).
(2) is attached. Specifically, a metal holding ring (4) having an internal screw (41) is fixed to the opening of the front cover (11), and a screw cylinder (22) is projected on the lens unit (2). Install the screw cylinder (22) into the inner screw (41)
Then, the lens unit (2) is attached to the housing (1) by screwing it into. Also, on the upper surface of the housing (1),
A finger hook (38) for adjusting the flange back protrudes upward, and a lock screw (14) for fixing the adjusted flange back is screwed.

As shown in FIG. 6, the retaining ring (4) is formed with an annular recess (42) surrounding the inner screw (41) on the surface facing the front cover (11). Three screw holes (44), (44) and (44) into which the three screws (43), (43) and (43) are to be screwed are formed outside the (42).

The front cover (11) has a retaining ring (4).
Is formed with a substantially circular opening (15) for attaching the projection, and three protrusions (16) (16) (16) for holding the adjustment ring (3) are formed on the inner peripheral wall of the opening (15). It is formed so as to be spaced from each other. Also, in the vicinity of each projecting piece (16), the screw (43)
Has a hole through it. Furthermore, the front cover
An arcuate recess (17) is formed in the center of the inner surface of the upper wall of (11), and a screw hole (18) into which the lock screw (14) is screwed is formed in the arcuate recess (17). ing. A pin (13) is provided on the inner surface of the front cover (11) at a position below the screw hole (18), and a pair of left and right screw holes (19) (1) are provided on both sides of the opening (15).
9) has been formed.

An opening (15) is formed on the inner surface of the front cover (11).
An elastic member (5) made of metal is installed on the upper part of the. The elastic member (5) has a leaf spring portion (5
1) and a tongue piece portion (52) extending downward along a vertical plane, and a circular hole (53) is formed in the tongue piece portion (52). As shown in FIG. 9, the elastic member (5) penetrates the pin (13) through the circular hole (53) and causes the leaf spring portion (51) to closely contact both sides of the arc-shaped recess (17). It is attached to the inner surface of the front cover (11).

Further, as shown in FIG.
Also, as shown in FIG. 6, a resin adjustment ring (3) is installed. The adjusting ring (3) has a cylindrical ring portion (31) provided with a fan-shaped collar portion (35) protruding therefrom, and the collar portion (35) provided with the finger hooks (38) protruding therefrom. Then, in the ring part (31),
A first cam portion (32), a second cam portion (33), and a third cam portion whose height varies along the circumferential direction on the end surface on the inner side of the housing.
(34) is projected. Further, the flange portion (35) has a fan-shaped opening into which the tip portion of the pin (13) of the front cover (11) is fitted.
(37) is formed. Furthermore, on the upper surface of the collar portion (35),
An arcuate surface (36) oscillating the center of curvature is formed on the rotation axis of the adjusting ring (3) along the opening (37).

The adjusting ring (3) has a ring portion (31) arranged outside the three projecting pieces (16), (16) and (16) of the front cover (11) to form an annular recess of the retaining ring (4). While fitting into (42),
The flange portion (35) is arranged inside the front cover (11) and is attached to the opening of the front cover (11). Further, the retaining ring (4) is fixed to the front cover (11) by the three screws (43), (43) and (43). As a result, the adjustment ring
The ring part (31) of (3) is the protruding piece (16) (1) of the front cover (11).
6) (16) is held inside the annular recess (42) of the retaining ring (4), and the adjusting ring (3) is rotatable but immovable in the axial direction. (See FIG. 7).

In this state, as shown in FIG. 10, the finger rest (38) of the adjusting ring (3) projects upward from the upper surface of the front cover (11). In the opening (15) of the front cover (11), the adjustment ring (3) is inserted between the three protruding pieces (16), (16) and (16).
First cam portion (32), second cam portion (33) and third cam portion (34)
Will appear. Further, as shown in FIG. 11 (a), an elastic member () is formed between the circular arc surface (36) of the collar portion (35) of the adjustment ring (3) and the circular arc recess (17) of the front cover (11). The leaf spring portion (51) of 5) is clamped, and the leaf spring portion (51) is slightly curved as shown by its elasticity. As a result, the adjustment ring (3)
The leaf spring portion (51) of the elastic member (5) is pressed against the circular arc surface (36) of the collar portion (35) of the elastic member (5) in the surface area, and a proper frictional resistance is given to the rotation of the adjusting ring (3). Of.

When the finger rest (38) of the adjusting ring (3) is operated to rotate the adjusting ring (3) against the frictional resistance, the first cam portion of the adjusting ring (3) shown in FIG. (32), the second cam portion (33) and the third cam portion (34) are attached to the front cover (1
Move along the arc line while protruding from the opening (15) of 1).

Inside the housing (1), as shown in FIG. 3, a CCD unit (6) is provided in which a mode switching device (7) and a circuit board (8) are screwed together and integrated.
The mode switching device (7) is for switching between a color mode and a monochrome mode, and is a mode switching device.
A filter device (9) equipped with the optical filter (91) is attached to (7). On the other hand, circuit board (8)
In the C, the image pickup surface of the CCD (81) is covered with a protective glass (85).
A CD package (80) is attached.

As shown in FIG. 7, the mode switching device (7) comprises a resin base (71) in the form of a box with one surface open on the circuit board (8) side, and both sides of the base (71) are provided. Has a pair of left and right ear pieces (72) (72) protrudingly provided. Each ear piece (72) has a hole (7
3) has been opened. The mode switching device (7) is fixed to the front cover (11) by two stepped screws (61) (61). As shown in FIG. 4, the stepped screw (61) is coaxially provided with a thick shaft portion (62) and a thin shaft portion (63), and a screw portion (64) is provided at the tip of the thin shaft portion (63). In addition to being projectingly provided, a head portion (66) for screwing operation is projectingly provided at a base end portion of the thick shaft portion (62) via a collar portion (65). The coil spring (67) is fitted to the thick shaft portion (62) of the stepped screw (61), and in this state, the stepped screw (61)
The thin shaft portion (63) penetrates the ear piece (72) of the front cover (11), and the screw portion (64) is screwed into the screw hole (19) of the front cover (11). As a result, the CCD unit (6) including the mode switching device (7) and the circuit board (8) is supported so as to be reciprocally movable within a predetermined range along the optical axis.
The coil spring (67) elastically biases the front cover (11).

On the base (71) of the mode switching device (7),
As shown in FIG. 8, on the surface facing the front cover (11), there are arc-shaped first ribs (75), second ribs (76) and second ribs (76) having an outer diameter that matches the inner diameter of the adjusting ring (3). Third rib (77)
Projectingly provided on these ribs, corresponding to the first, second and third cams (32), (33) and (34) of the adjusting ring (3), the first, second and third cams are provided. The followers (75a) (76a) (77a) are integrally molded. Also, the CCD (8
A rectangular window (74) for taking in the light beam from the lens unit (2) is opened at a position facing the (1).

As shown in FIG. 3, with the CCD unit (6) attached to the inner surface of the front cover (11), the first cam portion (32) and the second cam portion (33) of the adjusting ring (3) are provided. And the third
The cam portion (34) is the base (7) of the mode switching device (7).
1) 1st cam follower (75a), 2nd cam follower (76)
It comes into sliding contact with a) and the third cam follower (77a). Therefore,
When the finger rest (38) of the adjusting ring (3) is rotated to rotate the adjusting ring (3) in one direction, the first cam portion (32), the second cam portion (33) and the third cam portion (34) presses the first cam follower (75a), the second cam follower (76a), and the third cam follower (77a) in the optical axis direction, respectively, and causes the CCD unit (6) to move to the coil spring (67). It is moved in the direction of separating from the front cover (11) against the biasing force. This causes the flange back to change.

Even when the finger rest (38) is released in the process of operating the finger rest (38) to adjust the flange back, as shown in FIG. 11 (a), the elastic member (5) Leaf spring
Since the (51) slides on the circular arc surface (36) of the collar portion (35) of the adjusting ring (3) to give an appropriate friction resistance, the adjusting ring (3)
Is not reversed by the bias of the coil spring (67).

After adjusting the flange back in this way, as shown in FIG. 11 (b), the lock screw (14) is screwed in and the leaf spring portion (51) of the elastic member (5) is fixed by the tip of the screw. Press down strongly. As a result, the leaf spring portion (5) of the elastic member (5) is
1) Crim the circular surface (36) of the adjustment ring (3),
Lock (3). Here, since the tip of the lock screw (14) presses the circular arc surface (36) of the adjusting ring (3) via the leaf spring portion (51) of the elastic member (5), the tip of the lock screw (14) is The arcuate surface (36) of the adjusting ring (3) does not dig into the arc surface (36), and the surface contact realizes a reliable locked state. Further, since the pin (13) protruding from the front cover (11) is fitted into the opening (37) of the adjusting ring (3) to receive the lower pressure by the lock screw (14), the lower pressure is reduced. Adjusting ring by the action of
There is no fear that the collar portion (35) of (3) will be greatly deformed.

In the mode switching device (7), as shown in FIG. 7, the filter device (9) having the optical filter (91) and the dummy glass (92) inside the base (71) is reciprocally movable. Attached and the filter device
A motor (78) and a reciprocating drive mechanism (100) for reciprocating the (9) are provided.

The thickness of the dummy glass (92) is regulated so that the optical path length extension λ'according to the optical filter (91) shown in FIG. 21 (b) can be obtained. It
That is, in the example shown in the figure, the dummy glass 92 having a thickness of 2.88 mm is used. In this case, the thickness is 2.78
The optical path length extension λ ′ by the mm optical filter (91) is
Assuming that the refractive index n ₁ = 1.5443, λ ′ = (1-1 / n ₁ ) × 2.78 = 0.798 mm, while the extension λd ′ of the optical path length due to the dummy glass (92) is If the rate n ₂ = 1.5163, then λd ′ = (1-1 / n ₂ ) × 2.88 = 0.980 mm. Therefore, the optical path length when the optical filter (91) is interposed in the optical path is equal to the optical path length when the dummy glass (92) is interposed in the optical path, and the optical filter (91)
The shift of the focus due to the replacement of the dummy glass (92) with the dummy glass (92) becomes negligible.

As shown in FIG. 7, the reciprocating drive mechanism (100) comprises a screw shaft (79) and a guide shaft (70) which are installed in parallel to each other on a base (71), and one end of the screw shaft (79). The motor (78) is connected to the section. Further, the screw shaft (79) and the guide shaft (70) have resin reciprocating pieces (1
01) is engaged.

The reciprocating piece (101) includes an arm (10) on the frame body (109).
2) project, and install the screw shaft between the frame (109) and the arm (102).
Holds (79). A screw portion (108) is formed on a surface of the frame body portion (109) facing the screw shaft (79), and the screw portion (108) is screwed with the screw shaft (79). Further, the frame body portion (109) is formed with a first convex portion (103) and a second convex portion (104) toward the guide shaft (70), and guides both convex portions (103) (104). The shaft (70) is slidably pierced.

Further, a shaft portion (105) parallel to the guide shaft (70) is projectingly provided on the first convex portion (103) of the reciprocating piece (101), and a torsion spring (110) is provided on the shaft portion (105). Is fitted.
Both ends of the torsion spring (110) are extended in a mutually staggered direction so that the first arm portion (111) and the second arm portion (11
2) is formed. First of torsion spring (110)
The arm portion (111) extends along the arm (102) of the reciprocating piece (101) and elastically biases the arm (102) toward the frame body portion (109). As a result, the screw shaft (79) is connected to the arm (102) and the frame body.
Between the screw shaft (79) and the screw part (108) regardless of the dimensional variation during molding of the reciprocating piece (101) and the shape change due to the operating environment temperature. A stable screwed state is maintained. Further, the second arm portion (112) of the torsion spring (110) has a first protruding piece (projected on the second protruding portion (104) of the reciprocating piece (101) in a direction orthogonal to the guide shaft (70). 106) to prevent the torsion spring (110) from coming off, and the tip of the second arm portion (112) projects into the frame (109) in parallel with the guide shaft (70). The rotational force about the shaft portion (105) acting on the second arm portion (112) is received by being locked by the provided second projecting piece (107).

Therefore, when the screw shaft (79) is rotated by the drive of the motor (78), the reciprocating piece screwed into the screw shaft (79).
The (101) receives the screw driving force and reciprocates along the guide shaft (70).

The filter device (9) comprises a frame-shaped holder (90) as shown in FIG. 13, and an optical filter (91) and a dummy glass (92) are attached to the holder (90). At the end of the holder (90) on the guide shaft (70) side,
A plurality of arm pieces (90a) (90b) (90c) are projected, and these arm pieces (90a) (90b) (90c) sandwich the outer peripheral surface of the guide shaft (70) from both sides, and the guide shaft (70 ) Is slidably engaged. Further, the opposite end of the guide shaft (70) is slidably locked by a plurality of guide pieces (71a) (71a) (71a) protruding from the inner surface of the upper wall of the base (71). . The first and second convex portions (103) (104) of the reciprocating piece (101) of the reciprocating drive mechanism (100) are sandwiched between the plurality of arm pieces (90a) (90b) (90c). There is. As a result, the filter device (9) is reciprocally driven integrally with the reciprocating piece (101) of the reciprocating drive mechanism (100) between one moving end shown in FIG. 14 and the other moving end shown in FIG. It will be. The reciprocating drive mechanism (1) is provided on the inner surface of the base (71) of the mode switching device (7).
Stoppers (71b) (71c) for restricting both moving ends of the reciprocating drive mechanism (100) are provided on both sides with the 00) interposed therebetween.

When the motor (78) rotates in one direction from the state shown in FIG. 13, the reciprocating member (101) of the reciprocating drive mechanism (100) is rotated.
Moves to the right, and finally the reciprocating piece (10
When 1) reaches the right moving end received by the right stopper (71c), the optical filter of the filter device (9)
The color mode is set when (91) matches the position of the CCD (81). The motor (78) rotates in the opposite direction from the position shown in FIG. 13 so that the reciprocating member (10) of the reciprocating drive mechanism (100) is rotated.
1) moves to the left, and finally, the reciprocating piece (1
When 01) reaches the left moving end that is received by the left stopper (71b), the dummy glass (9) of the filter device (9) is
When 2) matches the position of the CCD (81), the monochrome mode is set.

In the reciprocating drive mechanism (100), even after the reciprocating piece (101) reaches one of the moving ends, the motor (7
The control method that continues the rotation of 8) for a certain period of time is adopted. This is to reliably position the reciprocating piece (101) at the moving end even if the rotation speed of the motor (78) varies. In this case, the screw shaft (79) is rotated by driving the motor (78) while the reciprocating piece (101) is prevented from moving by the stoppers (71b) and (71c). Similarly, the screw shaft (79) is a reciprocating piece.
It is sandwiched between the frame body (109) of (101) and the arm (102),
Since it remains screwed to the screw part (108),
When the screw shaft (79) rotates with the movement of 1) blocked, the arm (102) elastically deforms against the biasing force of the first arm portion (111) of the torsion spring (110). The meshing position of the screw shaft (79) and the screw portion (108) is displaced, and the screw shaft (79) is idle. Therefore, the screw shaft
There is no possibility that the screw shaft (79) and the thread of the screw portion (108) of the reciprocating piece (101) will be damaged by the rotation of the (79).

The filter device (9) is in the color mode position,
The position of the monochrome mode position or its intermediate position is detected, and after the filter device (9) reaches one of the moving ends, the rotation of the motor (78) is stopped after the lapse of the predetermined time. To do so, as shown in FIG. 16, the circuit board (8) is provided with a photo interrupter (82) including a light emitting part (83) and a light receiving part (84), while a holder for the filter device (9). (90) has a filter device
A shield plate (94) which should pass between the light emitting portion (83) and the light receiving portion (84) of the photo interrupter (82) is provided so as to project along with the reciprocating movement of (9) (see FIG. 7). When the power is turned on, as the initial operation, the filter device (9) is moved to the color mode position shown in FIG. 14 regardless of whether the subject is bright or dark, and then,
The brightness of the subject is judged, and the filter device (9) is moved to any mode position.

FIG. 16 shows a state in which the filter device (9) is set to the color mode position, and the CCD
The position of (81) and the position of the optical filter (91) match. At this time, the shield plate (94) is the photo interrupter (82).
The light from the light emitting portion (83) is incident on the light receiving portion (84). This causes the output signal of the photo interrupter (82) to go low. When the filter device (9) moves from this position and the shielding plate (94) enters between the light emitting part (83) and the light receiving part (84) of the photo interrupter (82) as shown in FIG. 17, the light emitting part ( The light from 83) to the light receiving part (84) is blocked. This causes the output of the photo interrupter (82) to go high. After that, the filter device (9) is further moved, and the dummy glass (9) is moved to the position of the CCD (81) as shown in FIG.
When reaching the monochrome mode position where the position of 2) is matched, the shield plate (94) passes through the photo interrupter (82), and light is again incident from the light emitting unit (83) to the light receiving unit (84). This causes the output of the photo interrupter (82) to go low.

The output of the photo interrupter (82) is supplied to a control microcomputer (not shown),
It is used to control the motor (78). That is, as shown in FIGS. 19A and 19B, for example, from the state of the color mode, the motor (78)
When setting the monochrome mode by rotating the counterclockwise (CCW), the signal from the photo interrupter (82)
First switch from low (LO) to high (HI), then
Switch from high to low. Therefore, the predetermined time T2 is measured from the time of switching from the high to the low, and the rotation of the motor is stopped when the predetermined time T2 has elapsed. The same applies to switching control from the monochrome mode to the color mode. Therefore, even if there is some variation in the rotation speed of the motor (78) or there is some error in the position of the photo interrupter (82), the rotation of the motor (78) should be continued for the predetermined time T2. This ensures that the filter device (9) reaches the moving end. or,
By limiting the idling time of the motor (78) within the predetermined value T2, the wear of the screw thread of the screw part (108) of the reciprocating piece (101) is suppressed.

When the filter device (9) falls into a locked state (hereinafter referred to as "mechanical lock") due to biting of dust or the like while the filter device (9) is moving, the following control is performed to release this mechanical lock. The method is adopted. For example, as shown in FIGS. 20 (a) and 20 (b), when the motor is rotated counterclockwise from the color mode to set the monochrome mode, a mechanical lock occurs while the filter device (9) is moving. In this case, the photo interrupter (82) does not switch to the low level even if the elapsed time T1 after starting the motor exceeds the predetermined threshold value Tmax.
The motor is rotated in reverse at the point of. As a result, when the output of the photo interrupter (82) is switched from high to low, the motor is stopped when the predetermined time T2 has elapsed thereafter. As a result, the filter device (9) is surely returned to the original color mode position. Then again
The motor is rotated counterclockwise to try switching from color mode to monochrome mode. The same applies when a mechanical lock occurs when switching from the monochrome mode to the color mode.

In the case of a mechanical lock caused by a slight abnormality such as a minute dust bite, the bite dust is eliminated by trying the mode switching twice or three times, and the mechanical lock is automatically operated. Will be released. However, when a mechanical lock is generated due to the occurrence of a serious abnormality, such a mechanical lock is not released by repeated mode switching, so the operation is stopped and an error message is issued.

As described above, according to the surveillance camera of the present invention, the flange back can be adjusted by directly operating the finger rest (38) without using a special tool, and the fine adjustment is easy. Is. Also, even if you release your hand from the finger rest (38) during the adjustment, the adjustment will not be misaligned, so you can use both hands to screw in the lock screw (14) after adjusting the flange back, The work of fixing the flange back becomes extremely easy.

Further, since a thin optical filter (91) formed by forming a color correction filter film (98) on one surface of two birefringent crystal plates (96) (97) is used, the thin optical filter (91) is used. The space between the reference surface for mounting the lens and the image pickup surface is enlarged by the amount corresponding to the change. As a result, the flange back CS of 12.5 mm
Also in the surveillance camera which employs the mount lens, the filter device (9) can be arranged in the space, whereby the color / monochrome can be switched.

Furthermore, the position of the pair of stoppers (71b) and (71c) can be accurately formed by integrally molding with the base (71), and the reciprocating drive mechanism (100) has a photo interface. Since the filter device (9) continues to be driven for a certain period of time after the output of the raptor (82) is switched, even if there is some error in the position of the photo interrupter (82), the filter device (9) , Make sure to move to a position where it can be received by one stopper. Therefore, using a single photo interrupter (82), the filter device (9)
Can be accurately positioned on both moving ends.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a surveillance camera according to the present invention.

FIG. 2 is a perspective view of the surveillance camera with a lens unit removed from a housing.

FIG. 3 is a partially cutaway side view showing a main part of the surveillance camera.

FIG. 4 is a side view showing an elastically supported state of a CCD unit.

FIG. 5 is a cross-sectional view showing a mounting state of an adjustment ring.

FIG. 6 is an exploded perspective view of a front cover, a holding ring, and an adjusting ring.

FIG. 7 is an exploded perspective view of a front cover, a mode switching device, and a circuit board.

FIG. 8 is a front view of the base of the mode switching device.

FIG. 9 is a rear view of the front cover.

FIG. 10 is a rear view showing a state in which an adjustment ring is attached to the front cover.

FIG. 11: When adjusting the flange back (a) and when fixing it (b)
6 is a rear view showing the states of the elastic member and the lock screw in FIG.

FIG. 12 is a perspective view of a reciprocating drive mechanism.

FIG. 13 is a rear view of the mode switching device while the filter device is moving.

FIG. 14 is a rear view of the mode switching device when the filter device reaches the color mode position.

FIG. 15 is a rear view of the mode switching device when the filter device reaches the monochrome mode position.

FIG. 16 is a partially cutaway front view showing the positional relationship between the photo interrupter and the shielding plate when the filter device reaches the color mode position.

FIG. 17 is a partially cutaway front view showing the positional relationship between the photo interrupter and the shielding plate during the movement of the filter device.

FIG. 18 is a partially cutaway front view showing the positional relationship between the photo interrupter and the shielding plate when the filter device reaches the monochrome mode position.

FIG. 19 is a signal waveform diagram illustrating a motor control method for mode switching.

FIG. 20 is a signal waveform diagram illustrating a motor control method when a mechanical lock occurs.

FIG. 21 is a diagram showing a configuration and an arrangement of an optical system of a camera.

FIG. 22 is an exploded perspective view showing a flange back adjustment mechanism in a conventional camera.

[Explanation of symbols]

(1) Housing (11) Front cover (12) Housing body (14) Lock screw (2) Lens unit (21) Objective lens (3) Adjustment ring (38) Fingerhold (32) First cam part (33) Second cam part (34) Third cam part (36) Arc surface (4) Retaining ring (5) Elastic member (51) Leaf spring part (6) CCD unit (61) Stepped screw (7) Mode switching device (71) Base (75a) 1st cam follower (76a) Second cam follower (77a) 3rd cam follower (8) Circuit board (81) CCD (9) Filter device (91) Optical filter (92) Dummy glass (100) Reciprocating drive mechanism

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-7-95453 (JP, A) JP-A-11-239356 (JP, A) JP-A-7-107355 (JP, A) JP-A-7- 23404 (JP, A) JP 2000-162668 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 5/232 G03B 17/12 H04N 5/225 H04N 5/238

Claims (4)

(57) [Claims] 1. A camera in which an image pickup device and an optical system are arranged in a housing (1), the optical axis of the optical system is surrounded by the housing (1) and is rotatable in a plane orthogonal to the optical axis. Supported and housing (1)
The finger ring (38) for rotation operation protruding outward of the adjustment ring (3) having an arc surface (36) having a center of curvature on its rotation axis, an image pickup device, and a housing ( In contrast to 1), the image pickup device unit is supported so as to be able to reciprocate within a predetermined range along the optical axis of the optical system and is elastically biased in one direction, and the adjustment ring (3) and the image pickup device unit. A cam mechanism, which is interposed between the cam mechanism and the adjustment ring (3), presses the image pickup device unit in a direction opposite to the elastic biasing direction, and is installed inside the housing (1). )
The elastic member (5) having the leaf spring portion (51) pressed against the circular arc surface (36) of the housing and the housing (1) are screwed through from the outside to the inside, and the tip portion is elastic member (5). ), A flange back adjusting mechanism characterized by including a lock screw (14) protruding toward the leaf spring portion (51). 2. The adjusting ring (3) comprises a ring portion (31) rotatably supported with respect to the housing (1) and a ring portion (3).
1) is provided with a protruding collar portion (35), the finger rest (38) is protruded on the collar portion (35) and the cylindrical outer peripheral surface (36) is formed, and the cam mechanism is adjusted. The flange back adjustment mechanism according to claim 1, comprising a cam surface formed on the ring portion (31) of the ring (3) toward the image pickup device unit, and a cam follower formed on the image pickup device unit. 3. The image pickup device unit comprises a circuit board (8) on which the image pickup device is installed, and a mode switching device for switching a photographing mode between a color mode and a monochrome mode.
The flange back adjusting mechanism according to claim 1 or 2, which is configured by integrating (7) and (7). 4. A mode switching device (7) is a filter device (9) interposed in an optical path from an objective lens to an image pickup device.
The filter device (9) includes an optical filter (91) for performing necessary optical processing in a color mode,
In the monochrome mode, a dummy glass (92) for correcting the optical path length to the same value as that in the color mode is provided together, and the filter device (9) is connected to the reciprocating drive mechanism (100).
The flange back adjustment mechanism according to claim 3, which is reciprocally driven between a color mode position where an optical filter (91) is interposed in the optical path and a monochrome mode position where a dummy glass (92) is interposed in the optical path.