JP3332876B2 - Color / monochrome switchable camera - 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 capable of switching between a color mode for performing color photographing and a monochrome mode for performing monochrome photographing.

[0002]

2. Description of the Related Art In a color-only camera, for example, as shown in FIG.
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) has a structure in which a color correction filter plate (99) is sandwiched between two birefringent crystal plates (96) and (97). Also, in a conventional camera dedicated to color, a so-called C having a long flange back of 17.526 mm is used.
Mount lens and one flange back
Two types are known, which employ a so-called CS mount lens as short as 2.5 mm.

For example, in the case of a camera having a flange back of 12.5 mm, the thickness t of the optical filter 95 is 4.38 m.
m, the thickness of the protective glass (85) of the CCD is 0.75 mm, 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) Is set to 5.6 mm. In this case, assuming that the refractive index of the optical filter (95) and the protective glass (85) is 1.5, the elongation λ of the optical path length caused by passing through the optical filter (95) and the protective glass (85) is λ = Since (1-1 / n) × (4.38 + 0.75) = 1.71 mm, the distance a from the lens mounting reference surface A of the housing (1) to the imaging surface of the CCD (81) is determined by the flange back.
(12.5 mm) and the elongation λ (1.71 mm) of the optical path length, which is 14.21 mm, which is the total value.

A surveillance camera dedicated to color has no problem in photographing in a bright place, but has a limit on the minimum illuminance of an object at night or in a dark place, and its performance is inferior to a surveillance camera dedicated to black and white. Will be. Therefore, the present inventors, in a camera employing a C-mount lens having a long flange back, a color mode in which the above-described optical filter (95) is interposed in the optical path from the objective lens (21) to the CCD (81), Instead of the optical filter (95), a color / monochrome switchable camera that can switch the shooting mode between monochrome mode with dummy glass interposed to correct the optical path length to the same value as in color mode developed. In this camera, a filter device including an optical filter and a dummy glass is reciprocated between a color mode position and a monochrome mode position to switch a photographing mode.

[0005]

However, in a camera employing a CS mount lens with a short flange back, if the above-mentioned color / monochrome switching type camera is realized, in the example of FIG. )
Since the distance a from the lens attachment reference plane A to the imaging surface of the CCD (81) is 14.21 mm, the screwing amount b (5.6 mm) of the lens unit (2) with respect to the lens attachment reference plane is The thickness t of the optical filter (95) (4.
38mm), the distance s (1.94 mm) from the surface of the protective glass (85) to the imaging surface of the CCD (81), and the absolute value (0.7 mm) of the flange back adjustment width are 1.59 mm.
Only a small margin is left. Therefore, it is practically impossible to arrange a member for holding the optical filter and the dummy glass and connecting them to the reciprocating drive mechanism in such a narrow space.

An object of the present invention is to realize a color / monochrome switching type camera in a camera employing a CS mount lens having a short flange back.

[0007]

In the present invention, the above object has been achieved by modifying the structure of an optical filter. That is, in the color / monochrome switching type camera according to the present invention, the filter device (9) is interposed in the optical path from the objective lens to the imaging device, and the filter device (9) has the color correction in the color mode. An optical filter (91) for performing necessary optical processing such as the above, and a dummy glass (92) for correcting the optical path length in the monochrome mode to the same value as in the color mode are provided. The filter device (9) is linked to the reciprocating drive mechanism (100), and a color mode position where the optical filter (91) is interposed in the optical path;
It is driven back and forth between monochrome mode positions with a dummy glass (92) interposed in the optical path. In addition, optical filter (91)
Is formed by forming a color correction filter film (98) on one side of a flat birefringent optical member.

In the color / monochrome switching type camera according to the present invention, as the optical filter, a thin optical filter (91) in which a color correction filter film (98) is formed on one surface of a flat birefringent optical member. Is adopted, the extra space between the lens mounting reference surface and the imaging surface is increased by the thickness reduction, and as a result, the optical filter and the dummy glass are held and connected to the reciprocating drive mechanism. , That is, the filter device (9) can be arranged.

Specifically, the optical member for birefringence of the optical filter (91) is constituted by bonding a plurality of birefringent quartz plates (96) and (97) to each other. Also, color correction filter film (9
Item 8) is formed by vapor-depositing an optical material capable of blocking infrared rays on one surface of an optical member for birefringence.

For example, in the camera shown in FIG. 21B, two crystal plates for birefringence (96) and (97)
An optical filter (91) in which a color correction filter film (98) is formed on one side by vapor deposition is adopted. In this camera, the thickness t 'of the optical filter (91) becomes 2.78 mm due to the omission of the conventional color correction filter plate (99), and passes through the optical filter (91) and the protective glass (85). The optical path length elongation λ ′ caused by the refractive index n
= 1.5, λ '= (1-1 / n) × (2.78 + 0.75) = 1.18m
m, the distance a ′ from the lens mounting reference plane A of the housing (1) to the imaging surface of the CCD (81) is the distance between the flange back (12.5 mm) and the extension of the optical path length λ ′ (1.18 mm). The total value is 13.68 mm. Accordingly, from this distance a ', the screwing amount b (5.6 mm) of the lens unit (2) with respect to the lens mounting reference plane, the optical filter (91)
Thickness t '(2.78 mm), the distance s (1.94 mm) from the surface of the protective glass (85) to the imaging surface of the CCD (81), and the absolute value (0.7 mm) of the flange back adjustment width. When subtracted, a margin of 2.66 mm is left, and FIG.
A space larger by 1.07 mm is created as compared with the conventional camera shown in FIG.

[0011]

According to the present invention, by using a thin optical filter, a color / monochrome switching type camera capable of switching between a color mode and a monochrome mode can be realized even in a camera employing a lens with a short flange back. You can do it.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a surveillance camera according to an embodiment of the present invention. The surveillance camera of the present 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. As shown in the drawing, the lens unit (2) and the CCD (81) are attached to each other.
An optical filter (91) formed by depositing a color correction filter film (98) on one side of a single birefringent crystal plate (96) (97).
To perform a color correction process such as blocking infrared rays. 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, the image is reproduced using only the luminance information among the luminance information and the color information obtained from the CCD (81).

The surveillance camera of this embodiment is shown in FIGS.
As shown in the figure, the front cover (11) and the housing body (1
A lens unit equipped with a metal housing (1) consisting of 2) and a front cover (11) with an objective lens (21)
(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 to the lens unit (2). The screw cylinder (22) is attached to the inner screw (41).
Then, the lens unit (2) is attached to the housing (1). Also, on the upper surface of the housing (1),
A finger hook (38) for adjusting the flange back projects upward, and a lock screw (14) for fixing the adjusted flange back is screwed therein.

As shown in FIG. 6, the holding ring (4) has an annular recess (42) surrounding the inner screw (41) on the surface facing the front cover (11). Outside the (42), three screw holes (44), (44), (44) for screwing the three screws (43), (43), (43) are formed.

A retaining ring (4) is provided on the front cover (11).
A substantially circular opening (15) for attaching the adjusting ring (3) is formed on the inner peripheral wall of the opening (15). They are formed at an interval from each other. Also, at the position near each protruding piece (16), the screw (43)
There is a hole through it. In addition, the front cover
(11) An arc-shaped recess (17) is formed in the center of the inner surface of the upper wall, and a screw hole (18) into which the lock screw (14) is screwed is formed in the arc-shaped recess (17). ing. A pin (13) protrudes from the inner surface of the front cover (11) below the screw hole (18), and a pair of left and right screw holes (19) (1) is provided on both sides of the opening (15).
9) is formed.

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

Further, on the inner surface of the front cover (11), FIG.
As shown in FIG. 6, a resin adjustment ring (3) is provided. The adjusting ring (3) has a fan-shaped flange (35) protruding from a cylindrical ring (31), and the finger hook (38) protruding from the flange (35). And, in the ring part (31),
A first cam portion (32), a second cam portion (33), and a third cam portion whose height changes along the circumferential direction on an end surface on the rear side of the housing.
(34) is protruded. Further, the flange (35) has a fan-shaped opening into which the tip of the pin (13) of the front cover (11) fits.
(37) is formed. Furthermore, on the upper surface of the collar (35),
Along the opening (37), an arc surface (36) swinging about the center of curvature is formed on the rotation axis of the adjustment ring (3).

The adjusting ring (3) has a ring portion (31) arranged outside the three projecting pieces (16), (16) and (16) of the front cover (11), and an annular concave portion of the retaining ring (4). (42)
The flange (35) is arranged inside the front cover (11) and attached to the opening of the front cover (11). The holding 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 projection (16) (1) of the front cover (11).
6) The adjustment ring (3) is locked inside the annular recess (42) of the retaining ring (4) by the (16) so that the front cover (11) can rotate and cannot move in the axial direction. (See FIG. 7).

In this state, as shown in FIG. 10, the finger catch (38) of the adjustment ring (3) projects upward from the upper surface of the front cover (11). In the opening (15) of the front cover (11), the adjusting ring (3) is inserted between the three protruding pieces (16), (16) and (16).
The first cam portion (32), the second cam portion (33) and the third cam portion (34)
Will come out. Further, as shown in FIG. 11A, an elastic member (36) is provided between an arc surface (36) of the flange portion (35) of the adjustment ring (3) and an arc-shaped concave portion (17) of the front cover (11). The leaf spring part (51) of (5) is pressed, and the leaf spring part (51) is slightly curved as shown in the figure due to its elasticity. As a result, the adjustment ring (3)
The plate spring portion (51) of the elastic member (5) is pressed against the circular arc surface (36) of the flange portion (35) in the surface region, and imparts appropriate frictional resistance to the rotation of the adjustment ring (3). It is.

When the finger ring (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).
The robot moves on an arc line while protruding from the opening (15) of (1).

As shown in FIG. 3, a CCD unit (6) in which a mode switching device (7) and a circuit board (8) are integrated by screwing them together is provided inside the housing (1).
The mode switching device (7) is for switching between a color mode and a monochrome mode, and is a mode switching device.
At (7), a filter device (9) equipped with the optical filter (91) is attached. Meanwhile, the circuit board (8)
Has a CCD (81) with an imaging surface covered with a protective glass (85).
A CD package (80) is attached.

As shown in FIG. 7, the mode switching device (7) has a box-shaped resin base (71) having one side open on the circuit board (8) side, and is provided on both side surfaces of the base (71). Are provided with a pair of left and right ear pieces (72) (72). Each earpiece (72) has a hole (7
3) has been established. 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) has a thick shaft portion (62) and a thin shaft portion (63) coaxially, and a screw portion (64) is provided at the tip of the thin shaft portion (63). A head (66) for screwing operation is projected from the base end of the thick shaft (62) via a flange (65). A coil spring (67) is fitted to the thick shaft portion (62) of the stepped screw (61).
The thin shaft portion (63) of the front cover (11) passes through the lug (72) of the front cover (11), and the screw portion (64) is screwed into the screw hole (19) of the front cover (11). Thereby, the CCD unit (6) including the mode switching device (7) and the circuit board (8) is supported so as to be able to reciprocate within a predetermined range along the optical axis, and
The coil spring (67) is elastically biased toward the front cover (11).

The base (71) of the mode switching device (7) includes:
On the surface facing the front cover (11), as shown in FIG. 8, arc-shaped first ribs (75), second ribs (76) having an outer diameter matching the inner diameter of the adjustment ring (3), and Third rib (77)
These ribs have first, second and third cams corresponding to the first, second and third cams (32), (33) and (34) of the adjusting ring (3). The followers (75a), (76a), and (77a) are integrally formed. Also, the CCD (8
At a position facing 1), a rectangular window 74 for taking in light rays from the lens unit 2 is opened.

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 adjustment ring (3). And third
The cams (34) are respectively connected to the bases (7) of the mode switching device (7).
1) 1st cam follower (75a), 2nd cam follower (76a)
a) and the third cam follower (77a). Therefore,
When the finger ring (38) of the adjustment ring (3) is rotated to rotate the adjustment ring (3) in one direction, the first cam portion (32), the second cam portion (33), and the third cam portion are formed. (34) respectively press the first cam follower (75a), the second cam follower (76a) and the third cam follower (77a) in the optical axis direction, and push the CCD unit (6) of the coil spring (67). It is moved in a direction away from the front cover (11) against the urging force. As a result, the flange back changes.

In the process of adjusting the flange back by operating the finger hook (38), even if the hand is released from the finger hook (38), as shown in FIG. Leaf spring part
(51) is in sliding contact with the arc surface (36) of the flange portion (35) of the adjusting ring (3) to give an appropriate frictional resistance.
Does not reverse due to the bias of the coil spring (67).

After adjusting the flange back in this way, as shown in FIG. 11B, a lock screw (14) is screwed in, and the leaf spring portion (51) of the elastic member (5) is screwed by its tip. Reduce pressure strongly. Thereby, the leaf spring portion (5) of the elastic member (5) is
1) is pressed against the circular surface (36) of the adjustment ring (3), and the adjustment ring
Lock (3). Here, since the tip of the lock screw (14) presses the arc surface (36) of the adjustment ring (3) via the leaf spring portion (51) of the elastic member (5), the tip of the lock screw (14) is The locking ring does not bite into the arc surface (36) of the adjustment ring (3), and a secure lock state is realized by surface contact. Further, a pin (13) protruding from the front cover (11) is fitted into the opening (37) of the adjustment ring (3) to receive the lower pressure by the lock screw (14). Adjustment ring by the action of
There is no fear that the flange portion (35) of (3) is greatly deformed.

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

The thickness of the dummy glass (92) is defined so that an optical path length elongation equivalent to the optical path length elongation λ 'by the optical filter (91) shown in FIG. You.
That is, in the example shown in the figure, a dummy glass (92) having a thickness of 2.88 mm is employed. In this case, the thickness is 2.78.
The optical path length elongation λ ′ by the optical filter (91) is
Assuming that the refractive index n ₁ = 1.5443, λ ′ = (1-1 / n ₁ ) × 2.78 = 0.79898 mm, whereas the extension λd ′ of the optical path length due to the dummy glass (92) is Assuming that the ratio n ₂ = 1.5163, λd ′ = (1-1 / n ₂ ) × 2.88 = 0.980 mm. Accordingly, 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)
And the displacement of the focus due to the replacement of the dummy glass (92) becomes negligible.

As shown in FIG. 7, the reciprocating drive mechanism (100) includes a screw shaft (79) and a guide shaft (70) installed in parallel with a base (71), and one end of the screw shaft (79). The part is connected to the motor (78). As shown in FIG. 12, a resin reciprocating piece (1) is attached to the screw shaft (79) and the guide shaft (70).
01) is engaged.

The reciprocating piece (101) has an arm (10) attached to the frame (109).
2) is projected, and the screw shaft is inserted between the frame (109) and the arm (102).
(79). The frame (109) has a screw (108) formed on the surface facing the screw shaft (79), and the screw (108) is screwed with the screw shaft (79). In the frame (109), a first convex portion (103) and a second convex portion (104) are formed toward the guide shaft (70), and the two convex portions (103) and (104) are guided. A shaft (70) penetrates slidably.

Further, a shaft (105) parallel to the guide shaft (70) protrudes from the first protrusion (103) of the reciprocating piece (101), and a torsion spring (110) is attached to the shaft (105). Is fitted.
Both ends of the torsion spring (110) extend in mutually staggered directions, so that the first arm portion (111) and the second arm portion (11).
2) is formed. 1st of torsion spring (110)
The arm portion (111) extends along the arm (102) of the reciprocating piece (101) and elastically urges the arm (102) toward the frame (109). As a result, the screw shaft (79) is connected to the arm (102) and the frame
(109) 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 use environment temperature. , A stable screwed state is maintained. Further, the second arm portion (112) of the torsion spring (110) has a first projecting piece (projecting from the second projecting 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 (112) projects from the frame (109) in parallel with the guide shaft (70). The rotational force around the shaft portion (105) acting on the second arm portion (112) is received by being locked by the provided second projecting piece (107).

Accordingly, when the screw shaft (79) is rotated by the driving of the motor (78), the reciprocating frame screwed to the screw shaft (79).
(101) receives the screw driving force and reciprocates along the guide shaft (70).

As shown in FIG. 13, the filter device (9) includes a frame-shaped holder (90), and the optical filter (91) and the 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) protrude, and these arm pieces (90a) (90b) (90c) sandwich the outer peripheral surface of the guide shaft (70) from both sides to form the guide shaft (70 ) Is slidably engaged. The opposite end of the guide shaft (70) is slidably locked by a plurality of guide pieces (71a) (71a) (71a) projecting from the inner surface of the upper wall of the base (71). . The first and second convex portions (103) and (104) of the reciprocating piece (101) of the reciprocating drive mechanism (100) are sandwiched between the plurality of arm pieces (90a) (90b) (90c). I have. Thereby, the filter device (9) is reciprocally driven between one moving end shown in FIG. 14 and the other moving end shown in FIG. 15 integrally with the reciprocating piece (101) of the reciprocating drive mechanism (100). 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) and (71c) for restricting both moving ends of the reciprocating drive mechanism (100) are protrudingly provided on both sides with the (00) therebetween.

When the motor (78) rotates in one direction from the state shown in FIG. 13, the reciprocating piece (101) of the reciprocating drive mechanism (100) is rotated.
Moves to the right, and finally, as shown in FIG.
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). When the motor (78) rotates in the reverse direction from the position shown in FIG. 13, the reciprocating frame (10) of the reciprocating drive mechanism (100) is rotated.
(1) moves to the left, and finally, as shown in FIG.
01) reaches the left moving end received by the left stopper (71b), the dummy glass (9) of the filter device (9).
2) matches the position of the CCD (81), and 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 of continuing the rotation of 8) for a certain time is adopted. This is to ensure that the reciprocating piece (101) is positioned at the moving end even if the rotation speed of the motor (78) varies. In this case, while the reciprocating piece (101) is prevented from moving by the stoppers (71b) (71c), the screw shaft (79) is rotated by the driving of the motor (78), as shown in FIG. The screw shaft (79) is
(101) is sandwiched between the frame (109) and the arm (102),
Since the threaded state with the screw part (108) is maintained, the reciprocating piece (10
When the screw shaft (79) rotates in a state where the movement of the torsion spring (1) is prevented, the arm (102) is elastically deformed against the urging force of the first arm (111) of the torsion spring (110). Then, the meshing position of the screw shaft (79) and the screw portion (108) is shifted, and the screw shaft (79) idles. Therefore, the screw shaft
There is no fear that the thread of the screw shaft (79) or the thread (108) of the reciprocating piece (101) will be damaged by the rotation of (79).

When the filter device (9) is in the color mode position,
In addition to detecting which of the monochrome mode position and the intermediate position exists, the rotation of the motor (78) is stopped after the predetermined time has elapsed after the filter device (9) reaches one of the moving ends. As shown in FIG. 16, a photo interrupter (82) including a light emitting unit (83) and a light receiving unit (84) is installed on a circuit board (8) as shown in FIG. (90) has a filter device
With the reciprocation of (9), a shielding plate (94) that passes between the light emitting unit (83) and the light receiving unit (84) of the photo interrupter (82) is protrudingly provided (see FIG. 7). When the power is turned on, as an initial operation, the filter device (9) is moved to the color mode position shown in FIG. 14 regardless of the brightness of the subject.
The brightness of the subject is determined, 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.
The position of (81) matches the position of the optical filter (91). At this time, the shielding plate (94) is the photo interrupter (82)
And the light from the light emitting section (83) enters the light receiving section (84). As a result, the output signal of the photo interrupter (82) becomes low. When the filter device (9) moves from this position and the shielding plate (94) enters between the light emitting portion (83) and the light receiving portion (84) of the photo interrupter (82) as shown in FIG. 17, the light emitting portion ( Light from 83) to the light receiving section (84) is blocked. As a result, the output of the photo interrupter (82) becomes high. Thereafter, 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 shielding plate (94) passes through the photo interrupter (82), and light is again incident on the light receiving unit (84) from the light emitting unit (83). This causes the output of the photointerrupter (82) to go low.

The output of the photo interrupter (82) is supplied to a control microcomputer (not shown).
It is used for controlling the motor (78). That is, as shown in FIGS. 19A and 19B, for example, the motor (78) is changed from the color mode state.
When rotating in the counterclockwise direction (CCW) to set the monochrome mode, the signal from the photo interrupter (82)
First it switches from low (LO) to high (HI), then
Switch from high to low. Therefore, a predetermined time T2 is measured from the time point of switching from high to low, and the rotation of the motor is stopped when the predetermined time T2 has elapsed. The same applies to the 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), it is necessary to continue the rotation of the motor (78) 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) to within a predetermined value T2, abrasion of the thread of the thread portion (108) of the reciprocating piece (101) is suppressed.

When the filter device (9) falls into a locked state (hereinafter referred to as a mechanical lock) due to biting of dust or the like during the movement of the filter device (9), the following control is performed to release the mechanical lock. The method is adopted. For example, as shown in FIGS. 20 (a) and (b), when the motor is rotated counterclockwise from the color mode state to set the monochrome mode, a mechanical lock occurs during the movement of the filter device (9). The photointerrupter (82) does not switch to low even if the elapsed time T1 after starting the motor exceeds a predetermined threshold value Tmax.
The motor is rotated in reverse at the time of. Thus, when the output of the photo interrupter (82) is switched from high to low, the motor is stopped when a predetermined time T2 has elapsed thereafter. This ensures that the filter device (9) returns to the original color mode position. Then again
The motor is rotated counterclockwise to try switching from the color mode to the 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 minor abnormality such as biting of fine dust, the mode switching is tried two or three times to eliminate the biting dust, and the mechanical lock is automatically turned off. Will be released. However, when a mechanical lock occurs due to the occurrence of a serious abnormality, such a mechanical lock is not released by repeating the mode switching, so that the operation is stopped and an error message is issued.

As described above, according to the monitoring camera of the present invention, the flange back can be adjusted by directly operating the finger hook (38) without using a special tool, and fine adjustment is easy. It is. Also, even if the hand is released from the fingerhold (38) during the adjustment, the adjustment does not shift, so after adjusting the flange back, the lock screw (14) can be screwed in using both hands, The work of fixing the flange back becomes extremely easy.

Since a thin optical filter (91) formed by forming a color correction filter film (98) on one surface of two birefringent quartz plates (96) and (97) is employed, The space between the lens attachment reference surface and the imaging surface is increased by the amount of the addition. As a result, CS with a flange back of 12.5 mm
In a surveillance camera employing a mount lens, a filter device (9) can be arranged in the space, thereby enabling switching between color and monochrome.

Further, the position of the pair of stoppers (71b) (71c) can be formed with high precision by being integrally molded with the base (71). Even after the output of the raptor (82) is switched, the driving of the filter device (9) is continued for a certain period of time. Therefore, even if there is some error in the position of the photointerrupter (82), the filter device (9) is , And surely move to a position where it can be received by one of the stoppers. Therefore, using a single photointerrupter (82), the filter device (9)
Can be accurately positioned at both moving ends.

[Brief description of the drawings]

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

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

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

FIG. 4 is a side view showing an elastic support state of the CCD unit.

FIG. 5 is a cross-sectional view illustrating an attached state of an adjustment ring.

FIG. 6 is an exploded perspective view of a front cover, a holding ring, and an adjustment 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 a 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 where an adjustment ring is attached to the front cover.

FIG. 11 (a) and (b) when fixing the flange back
It is a rear view showing the state of the elastic member and 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 when the filter device is moving.

FIG. 14 is a rear view of the mode switching device in a state where the filter device has reached the color mode position.

FIG. 15 is a rear view of the mode switching device in a state where the filter device has reached the monochrome mode position.

FIG. 16 is a partially cutaway front view showing a positional relationship between the photointerrupter and the shielding plate in a state where the filter device has reached the color mode position.

FIG. 17 is a partially cutaway front view showing a positional relationship between the photointerrupter and the shielding plate while the filter device is moving.

FIG. 18 is a partially cutaway front view showing a positional relationship between the photointerrupter and the shielding plate when the filter device has reached 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 illustrating a configuration and an arrangement of an optical system of a camera.

[Explanation of symbols]

 (1) Housing (11) Front cover (12) Housing body (14) Lock screw (2) Lens unit (21) Objective lens (6) CCD unit (7) Mode switching device (71) Base (78) Motor (79 ) Screw shaft (8) Circuit board (81) CCD (9) Filter device (90) Holder (91) Optical filter (92) Dummy glass (100) Reciprocating drive mechanism

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-239429 (JP, A) JP-A-60-66243 (JP, A) JP-A-2000-114502 (JP, A) JP-A-8-36157 (JP, A) JP-A-7-168134 (JP, A) JP-A-6-230218 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03B 11/00 G03B 7 / 08 G02B 5/20

Claims (3)

(57) [Claims] 1. A color / monochrome switchable camera in which a photographing mode can be switched between a color mode for performing color photographing and a monochrome mode for performing monochromatic photographing, from an objective lens to an image sensor. A filter device (9) is interposed in the optical path. The filter device (9) has an optical filter (91) for performing necessary optical processing in a color mode, and a color path length in a monochrome mode. A dummy glass (92) for compensating to the same value as in the mode is also provided, and the filter device (9)
Is connected to the reciprocating drive mechanism (100), and the optical filter
The optical filter (91) is reciprocally driven between a color mode position where (91) is interposed in the optical path and a monochrome mode position where the dummy glass (92) is interposed in the optical path. A color / monochrome switchable camera comprising a color correction filter film (98) formed on one side of an optical member. 2. The color / monochrome switching according to claim 1, wherein the birefringent optical member of the optical filter (91) is formed by bonding a plurality of birefringent quartz plates (96) and (97) to each other. Expression camera. 3. The color / color filter according to claim 1, wherein the color correction filter film is formed by vapor-depositing an optical material capable of blocking infrared rays on one surface of the birefringent optical member.
Monochrome switching camera.