JP2018077341A - Light quantity adjustment device and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an unnecessary space to reduce the size of a light quantity adjustment device that is mounted in a lens barrel.SOLUTION: A light quantity adjustment device comprises: an opening forming member that has a light passage opening; a holding blade that is driven by a driving part in order to advance into and retreat from the light passage opening and has a first filter attached thereto; a cover member that forms a space for driving the holding blade with the opening forming member; and slide contact parts that are provided on the opening forming member and come into slide contact with the holding blade when the holding blade advances into the light passage opening. The slide contact parts have portions different in distance from the opening forming member according to the distance from the light passage opening.SELECTED DRAWING: Figure 1

Description

  The present invention adjusts the amount of light incorporated in a lens barrel of a video camera or surveillance camera equipped with a device for putting in and out an IR (infrared light) cut filter or an AR (antireflection) filter. It relates to the device.

  In recent years, high-spec video cameras and surveillance cameras are increasingly equipped with a light amount adjustment device that switches between an IR cut filter and an AR filter and a light amount adjustment device that has only an IR cut filter insertion / removal function. That is, there is a need for a technique that blocks unnecessary light according to the situation in order to more naturally output light applied to the image sensor to a display or a screen.

  The human eye is responsive to light in the 400-780 nm wavelength region. In contrast, for example, a CCD responds with high sensitivity to light having a wavelength in the range of 400 to 700 nm, and further responds to light having a wavelength of less than 400 nm and light having a wavelength of more than 700 nm.

  When shooting with a camera in the daytime, an image sensor that senses IR light creates a reddish image when output to the screen. For this reason, it is necessary to insert an IR cut filter in the optical path during the daytime to block the IR light and create a natural image close to human eyes.

  On the other hand, at night or in an environment where the amount of light is relatively small, the sensitivity of the image sensor is insufficient. Therefore, it is necessary to capture more light and output it on a bright screen. In this case, the IR cut filter is removed and shooting is performed. At this time, an AR filter may be inserted as a dummy in order to eliminate the phase difference of light generated by removing the IR cut filter. In many cases, the IR cut filter and the AR filter have the same thickness. In addition, some low-spec model cameras are not equipped with an AR filter, and other products are available only by removing the IR cut filter from the optical path.

  Conventionally, as a light quantity adjusting device that switches between two filters alternately, as in Patent Document 1, the IR cut filter and the AR filter are arranged in parallel in a plane direction perpendicular to the light passing direction. Devices that can move in the same direction at the same time have been proposed. Further, when only the IR cut filter is taken in and out, a filter that inserts and removes the filter in the surface direction as disclosed in Patent Document 2 is disclosed.

JP 2003-348398 A JP 2008-3408 A

  However, in the filter switching mechanism as in Patent Document 1, the space for retracting the IR cut filter increases the size of the light amount adjusting device, and the size of the lens barrel increases accordingly. When the IR cut filter is inserted and the AR filter is retracted, the space where the IR cut filter was originally used is not used and is wasted.

  In addition, there is a configuration in which the light quantity adjusting device has a mechanism in which two types of filters are movable in opposite directions using a driving force transmission mechanism such as a gear. However, since the driving force is transmitted through a plurality of gears, the loss of force increases, and the space for a plurality of gears is required, resulting in an increase in the size of the apparatus.

According to the light amount adjustment device according to the present invention,
An opening forming member having a light passage opening;
A holding blade that is driven by a drive unit so as to be able to enter and retreat into the light passage opening and to which a first filter is attached;
A cover member that forms a space for driving the holding blade between the opening forming member;
Provided in the opening forming member, and when the holding blade advances and retracts to the light passage opening, a sliding contact portion that comes into sliding contact with the holding blade,
The light amount adjusting device characterized in that the sliding contact portion has a portion whose distance from the opening forming member varies depending on the distance from the light passage opening.

  In the light amount adjusting device of the present invention, when the filter is retracted from the light passage opening, the position in the light passage direction is changed, so that a useless space can be reduced and the device can be downsized.

The disassembled perspective view of the light quantity adjustment apparatus which concerns on one Example of this invention. The front view of the state which removed the cover of the light quantity adjustment apparatus which concerns on one Example of this invention. The other front view of the state which removed the cover of the light quantity adjustment apparatus which concerns on one Example of this invention. Sectional drawing of the light quantity adjustment apparatus which concerns on one Example of this invention. The other sectional view of the light quantity adjustment device concerning one example of the present invention. 1 is a cross-sectional view of an imaging device equipped with a light amount adjusting device according to an embodiment of the present invention. FIG. 6 is another cross-sectional view of an imaging apparatus equipped with a light amount adjusting device according to an embodiment of the present invention. The disassembled perspective view of the light quantity adjustment apparatus which concerns on the other Example of this invention. Detailed explanatory drawing of the light quantity adjustment apparatus which concerns on the other Example of this invention. The other detailed explanatory drawing of the light quantity adjustment apparatus which concerns on the other Example of this invention. The other detailed explanatory drawing of the light quantity adjustment apparatus which concerns on the other Example of this invention. The perspective view which shows how to attach the light quantity adjustment apparatus which concerns on one Example of this invention.

Example 1
FIG. 1 is an exploded perspective view of a light amount adjusting device according to the present invention. The IR cut filter 8 in the present invention is an optical filter deposited so as to cut (reflect) only the infrared ray of the light incident on the light amount adjusting device or inside the lens barrel. The substrate may be glass or resin. The infrared absorber 8a constituting the IR cut filter 8 has a light transmission characteristic with a transmittance of 50% at a wavelength in the wavelength band of 620 nm to 660 nm, and the infrared reflector 8b has a wavelength band of 670 nm to 690 nm. The IR cut filter 8 is configured by combining the infrared absorber 8a and the infrared reflector 8b. However, this wavelength is an example, and an infrared absorber or infrared reflector different from the wavelength range described above may be used.

  A base plate (opening forming member) 1 having a light passage opening 1a is formed of a molded resin component. A coil 2 is incorporated in the ground plane 1, and a yoke 3 is inserted and fixed to the ground plane 1 so as to surround the coil 2. The coil 2 incorporates a cylindrical bipolar magnet 2b (not shown) and is integrated with the shaft 2a. The yoke 3 is partially provided with a recess 3a toward the center of the yoke, and the magnetic pole of the magnet 2b and the recess 3a attract each other. A coil wire 2c is wound around the coil 2 and is drawn around the coil terminal 2d. The coil terminal 2d is connected to the drive circuit device through a substrate such as an FPC (flexible printed circuit board).

  When the coil wire 2c is energized through the coil terminal 2d, the coil 2 becomes an electromagnet and the internal magnet 2b rotates to follow the direction of the magnetic field formed by the coil wire 2c. At this time, the magnet 2b after the rotation stops in a state where the magnetic pole on the opposite side to that before the rotation is attracted to the recess 3a. Further, when the coil wire 2c is reversely energized, the magnetic pole of the magnet 2b is attracted to the original magnetic pole position. By switching the energization direction between positive and negative in this way, the shaft 2a rotates in the CW and CCW directions, and the coil 2 and the yoke 3 serve as actuators.

  The shaft 2a is lightly press-fitted into the central hole 4a of the arm 4 via the ground plate 1, and the arm 4 rotates in the CW and CCW directions by switching the energization direction to the coil wire 2c. The base plate 1 is provided with a stopper 1d and a stopper 1e. After the arm 4 is rotated by an appropriate amount, the arm portion 4d of the arm 4 collides with the stoppers 1d and 1e and stops.

  In the case of such an actuator, the two-pole magnet 2b is set so as to be attracted to and held by the recess 3a of the yoke 3 in a state where the actuator is stopped at two points of the stoppers 1d and 1e.

  The arm 4 is provided with a drive pin 4b. The holding blade 5 is a thin sheet material formed by press molding. The long hole 5a provided in the holding blade 5 is engaged with the drive pin 4b, and the other long holes 5b and 5c are engaged with the guide pins 1b and 1c of the base plate 1, respectively. In this configuration, when the coil 2 is energized from the coil terminal 2d through the coil wire 2c, the arm 4 rotates and the holding blade 5 moves in a direction along the guide pins 1b and 1c.

  An IR cut filter 8 is attached to the holding blade 5 by adhesion. Since the IR cut filter 8 is integrated with the holding blade 5, the IR cut filter 8 is inserted into and retracted from the light passage opening 1 a by energizing the coil 2. To do. When the IR cut filter 8 is inserted into the light passage opening 1 a of the ground plane 1, it has a size that completely covers the light passage opening. More specifically, it is formed slightly larger than the light passage opening 1a.

  The cover (cover member) 9 has holes 9b and 9c, which engage with the positioning shafts 1j and 1g of the base plate 1, so that the base plate 1 and the cover 9 are in an appropriate positional relationship. That is, it engages with the ground plane 1 while forming a space for driving the holding blade 5 between the ground plane 1 and the cover 9. In a state where the cover 9 is positioned with respect to the ground plane 1 by the positioning shafts 1j and 1g, the ground plane 1 and the cover 9 are fastened by screws 10a and 10b. The screw 10a passes through the hole 9d of the cover and is inserted into the screw hole 1h of the base plate 1 by self-tapping. Similarly, the screw 10b passes through the hole 9e of the cover and is inserted into the screw hole 1i of the base plate 1 by self-tapping. By doing so, the main plate 1 and the cover 9 are fixed. The IR cut filter 8 is inserted into the optical axis passing through the light passage opening 1a of the base plate 1 and the light passage opening of the cover 9, thereby exhibiting characteristics as an optical filter.

  FIG. 2 shows a state in which the cover 9 is removed in a state where the IR cut filter 8 is inserted into the light passage opening 1 a of the base plate 1. The base plate 1 is provided with a rail (sliding contact portion) 1m, and the holding blade 5 is slid along the rail surface by a long hole 5b provided to engage with the rail 1m. . The same applies to the rail 1n provided on the main plate 1. FIG. 3 shows a state in which the energization direction to the coil 2 is reversed and the arm 4 is rotated in the direction opposite to that in FIG. As the arm 4 rotates, the elongated hole 5a of the holding blade 5 engaged with the drive pin 4b follows, and the IR cut filter 8 bonded to the holding blade 5 retracts from the light passage opening 1a. The cover 9 is provided with a recess 9a so as not to interfere with the guide pin 1c of the base plate 1. The guide pin 1c is fitted so as to be inserted into the recess 9a, and the holding blade 5 can be moved without coming out of the guide pin 1c. Similarly, the cover 9 is provided with another recess 9a so as not to interfere with the guide pin 1c of the base plate 1. By fitting the guide pin 1b so as to be inserted into the recess 9a, the holding blade 5 is It can move without coming out of the guide pin 1b.

  In the case of a configuration equipped with such an actuator, it is possible to hold two points with a dipole magnet, so when inserting and retracting two different filters to the light passage opening, it is necessary to operate the power source system as a drive source for a long time. No, the filter position can be held in a non-energized state.

  FIG. 4 shows a cross-sectional view of a cross section G passing through the rail 1m and the rail 1n in FIG. FIG. 5 shows a cross-sectional view of a cross section H passing through the rail 1m and the rail 1n in FIG. The cover 9 is provided with rails 9m and 9n. The rails 1m and 9m, and the rails 1n and 9n face each other substantially in parallel, and the rails 1m and 9m and the rails 1n and 9n are arranged in the direction of the light passage opening when the holding blade 5 is retracted from the light passage opening 1a. Has an inclined portion which is a portion having an inclination so as to be movable. The inclined portion is provided such that the distance from the ground plane 1 increases as the distance from the light passage opening 1a increases in the surface direction of the ground plane 1 perpendicular to the optical axis direction.

  The forming portion 5m between the elongated hole 5c of the holding blade 5 and the outer shape is between the rail 1m and the rail 9m, and the forming portion 5n between the elongated hole 5b of the holding blade 5 and the outer shape is the rail 1n and the rail 9n. It is arranged between. The holding blade 5 is moved by the driving of the arm 4, but the movement locus is restricted by the forming portion 5 m between the rail 1 m and the rail 9 m and the forming portion 5 n between the rail 1 n and the rail 9 n. When the filter 8 retracts from the light passage opening 1a, the holding blade 5 moves in a direction away from the light passage opening 1a in the light passage direction.

  FIG. 6 is a cross-sectional view of the imaging apparatus in a state where the lens barrel and the lens are attached to the light amount adjusting apparatus according to the present invention in the state of FIG. 4, and FIG. 1 is a cross-sectional view of an imaging apparatus in a state where a lens barrel and a lens are attached to the apparatus. In the state of FIG. 6 in which the IR cut filter 8 is inserted into the light passage opening 1a, an appropriate distance is secured between the lens 270 and the IR cut filter. The state of FIG. 7 in which the IR cut filter is retracted from this state is closer to the lens side in the light passing direction than the state of FIG.

  In the case of such a movable form, the lens and the component for fixing the lens can be brought closer to the light amount adjusting device, and the height of the lens barrel can be reduced as compared with the conventional configuration. In addition, by retracting the filter from the light passage opening and placing the filter in the light passage direction closer to the lens and other parts than at the time of insertion, it is possible to create a space for housing other parts and to function as a lens barrel. Can be added. Alternatively, the lens barrel can be reduced in size.

(Example 2)
FIG. 8 shows an exploded perspective view of the second embodiment.

  The holding blade 6 and the AR filter 7 are added to the configuration described in the first embodiment. The holding blade 6 has long holes 6a, 6b, and 6c. The long hole 6a is inserted into and engaged with the drive pin 4c of the arm 4, and the long hole 6c is inserted into the guide pins 1p and 1q of the base plate 1 to be engaged. Match. An AR filter 7 is attached to the holding blade 6. The AR filter 7 is set to a size that covers the light passage opening 1 a of the ground plane 1, and has a size that does not cover the light passage opening 1 a when retracted.

  The arm 4 is provided with drive pins 4b and 4c. The holding blade 6 is formed by press molding and is a thin sheet material. The long hole 6a provided in the holding blade 6 is engaged with the drive pin 4b, and the other long holes 6b and 6c are engaged with the guide pins 1p and 1q of the base plate 1, respectively.

  When the coil 2 is energized from the coil terminal 2d through the coil wire 2c, the arm 4 rotates and the holding blade 5 moves in the longitudinal direction of the holding blade. An IR cut filter 8 is bonded to the holding blade 5, and the AR filter 7 is bonded to and integrated with the holding blade 6, so that the coil 2 can be inserted into and retracted from the light passage opening 1 a by energizing the coil 2. . When the AR filter 7 is inserted into the light passage opening 1 a of the ground plane 1, the AR filter 7 has a size that completely covers the light passage opening.

  FIG. 9A shows a state where the IR cut filter 8 is inserted into the light passage opening 1a. FIG. 9B shows a cross-sectional view of the rail 1m (MM cross section in FIG. 9A). FIG. 9C shows a cross-sectional view in the longitudinal direction of the center of the light passage opening (NN cross section in FIG. 9A), and the IR cut filter 8 and the AR filter 7 are in the same position in the light passage direction. Indicates the state.

  FIG. 10A shows a state in which the holding blade 5 and the holding blade 6 are in the same position in the light passing direction. As the arm 4 rotates, the holding blade 5 and the holding blade 6 are movable in directions opposite to each other in the longitudinal direction. 10B shows a cross-sectional view of the rail 1m in FIG. 10A (the KK cross-section in FIG. 10A). A forming portion 5m of the holding blade 5 sandwiched between the rail 1m of the base plate 1 and the rail 9m of the cover 9 is moved in the light passing direction and the longitudinal direction from the state of FIG. In addition, the filter 7 is moved with the movement of the holding blade 5. The position of the holding blade 6 in the light passing direction is regulated by the rail 1r provided on the main plate 1 and the rail 9r provided on the cover 9, and the holding blade 6 and the filter 7 move in the longitudinal direction but move in the light passing direction. Not done. That is, the holding blade 6 advances and retreats with respect to the light passage opening 1a while keeping the distance from the base plate 1 constant.

  However, in consideration of the dimensional accuracy of the holding blade 6, the base plate 1, and the cover 9, the distance between the rail 1 r and the rail 9 r is sufficiently secured than the thickness of the holding blade 6. FIG. 10C shows a longitudinal section of the center of the light passage opening in FIG. The holding blade 5 and the holding blade 6 are substantially in the same position with respect to the light passing direction, and are in a state immediately before the holding blade 5 and the holding blade 6 or the filter 7 and the filter 8 are moved in the light passing direction.

  FIG. 11A shows a state where the holding blade 5 and the holding blade 6 or the filter 7 and the filter 8 are reversed from the state of FIG. The arm 4 rotates until it collides with the stopper 1e, and accordingly, the holding blade 5 and the holding blade 6 move in directions opposite to the longitudinal direction. FIG. 11B is a cross-sectional view of the rail 1m in FIG. The forming portion 5m of the holding blade 5 passes between the rails 1m and 9m, and the IR cut filter 8 is retracted from the light passage opening 1a and moved to a position where the AR filter 7 is completely inserted into the light passage opening 1a. The holding blade 5 is also moved in the longitudinal direction and the light passing direction. At this time, the position of the holding blade 6 in the light passing direction is substantially the same as that in FIGS. 9 and 10, and moves in the longitudinal direction according to the rotation of the arm 4.

  The holding blade 6 moves in the longitudinal direction, while the holding blade 5 further moves in the light passing direction. As a guide for movement in the light passing direction, the rail 1m and the rail 9m contribute. That is, the movement toward the light passage opening direction is performed only by receiving the urging force accompanying the rotational movement of the arm 4 by the inclined portions provided on the rail 1m and the rail 9m. Furthermore, in order to stabilize the attitude | position of the holding blade 5, the guide pin 1c inserted with the elongate hole 5b with the rail 1n is provided.

  The height of the guide pin 1c (normal direction with respect to the ground plane) is higher than the height of the rail 1n. That is, since the guide pin 1c can be kept inserted through the elongated hole 5b with respect to the holding blade 5 that is placed on the top of the rail 1m and the rail 1n, the same height is formed. The holding blade 5 can be supported in cooperation with the driven pin 4b, and the sliding direction of the holding blade 5 that moves in the longitudinal direction while moving in the light passing direction can be stabilized.

  At this time, the holding blade 5 and the holding blade 6 may have the same shape. The IR cut filter 8 and the AR filter 7 may have a reverse positional relationship.

  The IR cut filter and the AR filter may be an optical film such as an ND filter or a light shielding film.

  In this way, the holding blade 5 and the holding blade 6 are switched to each other and advance and retract into the light passage opening 1a. Between FIG. 10A and FIG. 11A, it is preferable to form a state where both the holding blade 5 and the holding blade 6 are in a position retracted from the light passage opening 1a.

  FIG. 12 shows an example when the electromagnetic driving device according to the embodiment of the present invention is attached to the lens barrel 100. The light amount adjusting device 200 is inserted into the insertion port 110 provided in the lens barrel 100, the matching portion 120 and the fixing portion 210 are aligned, and fixed by screw tightening.

  As a result, as compared with the configuration in which the IR cut filter 7 moves only in the longitudinal direction, it is possible to bring the lens approaching the vicinity of the light passage opening 1 a and the component holding the lens closer to the IR cut filter 7. The aperture unit can be reduced in height by bringing the lens and the component holding the lens closer to the IR cut filter. Further, by bringing the lens and the component holding the lens closer to the IR cut filter, other components can be accommodated in the lens barrel, and the function of the lens barrel can be increased.

  Further, since the two filters such as the IR cut filter 8 and the AR filter 7 are located at substantially the same position in the light passing direction, optical characteristics such as light refraction and phase difference can be stabilized.

DESCRIPTION OF SYMBOLS 100 Lens barrel 110 Electromagnetic drive device insertion port 120 Matching part 200 Light quantity adjustment device 210 Matching part 220 Opening part 230 Actuator 240 Gear mechanism 250 Filter holding blade 260 IR cut filter 270 AR filter 280 Lens 300 Imaging element 1 Ground plate 1a Light passage Opening 1b, 1c Guide pin 1d, 1e Stopper 1g, 1j Positioning shaft 1h, 1i Screw hole 1m, 1n, 1p, 1q Rail 2 Coil 2a Shaft 2b Magnet 2c Coil wire 2d Coil terminal 3 Yoke 3a Recess 4 Arm 4a Center hole 4b, 4c Drive pin 4d Arm part 5 Holding blade 5a, 5b, 5c Long hole 5m, 5n Forming part 6 Holding blade 6a, 6b, 6c Long hole 6m, 6n Forming part 7 AR filter 8 IR cut filter 9 Cover 9b, 9c , 9d, 9e Hole 10a 10b screw

Claims (7)

An opening forming member having a light passage opening;
A holding blade that is driven by a drive unit so as to be able to enter and retreat into the light passage opening and to which a first filter is attached;
A cover member that forms a space for driving the holding blade between the opening forming member;
Provided in the opening forming member, and when the holding blade advances and retracts to the light passage opening, a sliding contact portion that comes into sliding contact with the holding blade,
The light amount adjusting device according to claim 1, wherein the sliding contact portion has a portion whose distance from the opening forming member differs depending on a distance from the light passage opening. The sliding contact portion is a rail-shaped first rail, and the cover member is provided with a second rail facing the first rail,
2. The light amount adjusting device according to claim 1, wherein a part of the holding blade advances and retreats with respect to the light passage opening in a state where the holding blade is sandwiched between the first rail and the second rail. The sliding contact portion has an inclination such that the distance between the opening forming member and the holding blade is widened between when the first filter enters the light passage opening and retracts.
Other holding blades attached with a second filter that advances and retreats to the light passage opening,
The light quantity adjusting device according to claim 2, wherein the other holding blade advances and retreats with respect to the light passage opening while maintaining a constant distance from the opening forming member.   The light quantity adjusting device according to claim 3, wherein the first filter and the second filter are switched to each other and enter the light passage opening.   5. The light amount adjustment according to claim 3, wherein the first filter and the second filter have substantially the same position from the light passage opening with respect to a light passage direction when entering the light passage opening. apparatus. An opening forming member having a light passage opening;
A holding blade that is driven by a drive unit so that it can be inserted into and retracted from the light passage opening, and to which a filter is attached;
A cover member for forming a space for driving the holding blade between the opening forming member and
As the holding blade is driven by the drive unit so as to be retracted from the light passage opening, the distance from the opening forming member increases. An imaging device provided with the light quantity adjustment apparatus as described in any one of Claims 1-6.

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