CN1766520A - Position-detecting system - Google Patents

Abstract

The present invention provides a position detection system for detecting the position of a movable member corresponding to a fixed member. The system includes a plurality of light sources, a position sensing device and a light source controller. The light source is provided on one of the fixed member and the movable member, and emits concentrated light. The position sensing device is provided on the other of the fixed member and the movable member. The position sensing device receives the concentrated light and outputs a position signal corresponding to the relative position according to the received position of the concentrated light. The light source controller controls on/off states of a plurality of light sources. When the position sensing device detects only one spot from the light source, the light source controller turns on one of the light sources continuously, and when the position sensing device detects multiple spots from the light source, the light source controller turns on both Or more than two light sources flashing.

Description

position detection system

technical field

The present invention relates to a position detecting system that detects the position of a two-dimensionally moving object. In particular, the present invention relates to a position detection system used as a component of an anti-shake device of a digital camera and which detects the relative position of an imaging device with respect to the optical axis of a photographing lens.

Background technique

Conventionally, anti-shake devices (camera shake compensation devices) are used in the field of digital cameras. The anti-shake device prevents or compensates for image blur produced on an imaging surface of the imaging device. This is done by moving the compensating lens along a plane perpendicular to the optical axis of the photographic lens to eliminate camera shake, which is produced during photography. The anti-shake device is provided with a position sensing system to detect the relative position of the imaging device with respect to the optical axis of the photographing lens (refer to Japanese Unexamined Patent Publication No. 2001-117129). In this type of position sensing system, a two-dimensional position sensing device (PSD) receives a spotlight emitted by a light source (LED), and thereby detects a relative position according to the position of the received spotlight. In particular, a two-dimensional position sensing device (PSD) and a light source (LED) are provided on a fixed member and a moving member. The movement of the movable member or object is detected by detecting the relative position of the movable member corresponding to the fixed member by detecting the position of the light accompanied by the two-dimensional position sensing device.

Contents of the invention

The two-dimensional position sensing device is a CCD in the shape of a square, the length of each side of which is at most 2mm. Therefore, according to the anti-shake device using this type of position sensing device, it is only possible to compensate the shake in the range of about ±1 mm around about the middle position. Because of this limitation, a two-dimensional position sensing device with a large light receiving surface should be used. However, this increases size and cost.

Also, although a conventional two-dimensional position sensing device can detect the position, moving direction, and displacement of an object having motion describing a two-dimensional trajectory, it cannot detect the rotation of the object even when the object rotates on a two-dimensional plane. is also like this.

An aspect of the present invention is to provide a position detection system capable of obtaining position detection with a wider range than conventional position detection devices by using a generally sized position sensing device.

Another aspect of the present invention is to provide a position detection system capable of detecting two-dimensional rotation in a plane, as well as two-dimensional translation.

According to one aspect of the present invention, a position detection system is provided for detecting a relative position of a movable member corresponding to a fixed member. The system includes a plurality of light sources, a position sensing device, and a light source controller.

The light source is provided on one of the fixed member or the movable member, and emits concentrated light. A position sensing device is provided on the other of the fixed member or the movable member. The position sensing device receives the concentrated light and outputs a position signal corresponding to the relative position according to the received position of the concentrated light. The light source controller controls on/off states of a plurality of light sources. When the position sensing device detects only one spot from the light source, the light source controller turns on one of the light sources continuously, and when the position sensing device detects multiple spots from the light source, the light source controller turns on both Or more than two light sources flash.

The light source controller can control the on/off state of the light source according to the position signal. The light source may be arranged in an area larger than the light-receiving area of the light-sensing device that detects the concentrated light. The distance between the light sources may be smaller than the width of the light-receiving area of the light-sensing device that detects the concentrated light.

The position detection system can also be configured so that when a spotlight from one of the light sources shines on one edge of the receiving area, a spotlight from the other light source shines on the other side of the receiving area.

The position sensing means may be a two-dimensional area sensor, and the light receiving area may have a rectangular shape in which four concentrated lights are simultaneously detected at four corners of the light receiving area.

Preferably, even when multiple light sources are flashing, only one of the light sources is turned on at the same time. In this case, two of the light sources can flash alternately with the same period.

Further, the light sources can flash so that three or more light sources are turned on in sequence.

The position detection system may further include a position calculator, which may calculate a relative position according to the on/off state of the light source.

According to another aspect of the present invention, a position detection system includes a plurality of light sources, a position sensing device and a light source controller. The light source controller can flash each light source so that each light source is turned on in turn.

Further, according to another aspect of the present invention, a position detection system provided includes a movable member, a light source unit, a position sensing device, a light source controller, and a calculator.

The movable member moves on a two-dimensional plane relative to the fixed member. The light source unit is provided on one of the fixed member and the movable member. The light source unit includes a plurality of light emitting devices which are separated by a predetermined distance. The position sensing device is provided on the other of the fixed member and the movable member. The position sensing device receives light from the light source unit and detects the position of the received light. The light source controller selectively turns on one light emitting device in a predetermined sequence. According to the two pairs of position data, the calculator calculates the motion direction, displacement and rotation of the movable member. A pair of position data indicates a position at which light from a pair of light emitting devices is detected. The other pair of position detection data indicates a position at which light from the pair of light emitting devices is detected at predetermined time intervals after the pair of position data is detected.

The number of light emitting devices in the plurality of light emitting devices may be two. The light source controller alternately turns on the two light emitting devices at the same time interval. The movable member is rotatably supported relative to the fixed member.

Description of drawings

Objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings, in which:

FIG. 1 illustrates the configuration of a digital camera provided with a position detection system used in a first embodiment of the present invention;

Fig. 2 is a plan view of an anti-shake mechanism (mechanism);

Fig. 3 is a sectional view of the anti-shake mechanism;

Figure 4 is a block diagram of a control system used in anti-jitter operations;

Fig. 5 illustrates the arrangement (arrangement) of LED;

Figure 6 illustrates an arrangement of LEDs and position sensing means, facing each other.

Figure 7 shows the on/off state of the LED;

Fig. 8 illustrates the arrangement of LEDs in the second embodiment;

Fig. 9 shows the on/off state of the LED in the second embodiment;

10 is a sectional view of a position detection system used in a third embodiment of the present invention;

FIG. 11 illustrates a light-receiving area of a position sensing device of a position detection system of a third embodiment;

Fig. 12 is a timing chart showing on/off states of two lamp emission of the third embodiment;

Fig. 13 is a block diagram showing a schematic circuit diagram of a third embodiment;

14 is a sectional view of a digital camera provided with an anti-shake device for a third embodiment of the present invention;

Fig. 15 is a block diagram representing a schematic circuit diagram of an anti-shaking device;

Fig. 16 is a rear view showing the main part (main part) of the anti-shake device;

Fig. 17 is a cross-sectional view of the anti-shake device along line VIII-VIII of Fig. 16; and

FIG. 18 is a sectional view of the anti-shake device taken along line IX-IX of FIG. 16 .

Detailed ways

The invention is described with reference to the embodiments represented in the drawings.

1-5 illustrate a first embodiment of the present invention, in which the present invention is applied to a digital camera as an embodiment.

Referring to FIG. 1 , a lens block 12 or a photographing optical system is provided inside a camera body. Behind the lens block 12, an anti-shake device 20 provided with an imaging mechanism (CCD) 23 is arranged.

The housing 21 of the anti-shake mechanism 20 moves along a plane perpendicular to the optical axis "A" of the photographing optical system, whereby camera shake caused by hand shake can be compensated.

Referring to FIG. 2 and FIG. 3 , the structure of the anti-shake mechanism 20 can be explained. However, anti-shake methods or camera shake compensation methods are well known in the art, and thus descriptions of these methods are omitted.

The fixing member 31 is fixed to a retaining frame (not shown) provided inside the camera body. A first support member 32 , a second support member 33 , a first yoke 34 , and a second yoke 35 are provided on the fixing member 31 . A base plate 22 is attached to a casing 21 (movable member). Also, an imaging device 23 is attached on the front surface of the base 22 and a coil printed circuit board 24 is attached on the rear surface of the base 22 . Bearing members 25 and 26 provided on the outer side of the casing 21 are movably guided by horizontal guide-shafts 27 and 28 , which extend laterally in FIG. 2 . As shown in FIG. 2 , left ends of the horizontal guide shafts 27 and 28 are connected by a vertical guide shaft 29 . The vertical guide shaft 29 is supported by the first supporting member 32, whereby the vertical guide shaft 29 can move in the vertical direction of FIG. 2 . It should be noted that the right ends of the horizontal guide shafts 27 and 28 are guided by the second support member 33 in the vertical direction.

Thus, housing 21 , base 22 , imaging device 23 and coil printed circuit board 24 in FIG. 2 can move laterally along horizontal guide axes 27 and 28 . Also, the housing 21 etc. in FIG. 2 can move longitudinally along the vertical guide shaft 29 together with the horizontal guide shafts 27 , 28 .

The first magnet 36 and the second magnet 37 are connected inside the first yoke 34 and the second yoke 35, respectively. A first coil 38 and a second coil 39 forming a spiral sheet-like coil pattern are provided on the surface of the coil printed circuit board 24 . The first coil 38 faces the first magnet 36 and the second coil 39 faces the second magnet 37 .

Therefore, according to the interaction (interaction) between the current supplied to the first coil 38 and the magnetic field generated by the first magnet 36, the housing 21 and other integrated components in FIG. mobile. Moreover, according to the interaction between the current supplied to the second coil 39 and the magnetic field generated by the second magnet 37, the housing 21 and other integrated components in FIG. 2 are guided by the horizontal guide shafts 27 and 28 and moved laterally. .

As shown in FIG. 3 , an opening 41 having almost the same size as the imaging device 23 is formed on the housing 21 at a position facing the imaging device 23 . Also, inside the housing 21, an optical low-pass filter 42 is provided. The optical low-pass filter 42 is fixed to the inner surface of the housing 21 by an urging member 43 interposed between the optical low-pass filter 42 and the imaging device 23 .

Opposite the first coil 38 , a rectangularly extending plate section 51 is formed, which extends downward from the coil printed circuit board 24 . On the surface of the extended plate member 51 , on the side opposite to the fixing member 31 , a light emitting unit 52 is provided. Also, on the fixing member 31 , at a position opposite to the light emitting unit 52 , a position sensing device 53 such as a two-dimensional area sensor is arranged. As will be described later, referring to FIG. 5, the light emitting unit 52 has nine LEDs (light sources) 52a-52i that emit concentrated light. The LEDs are distributed in an area larger than the light receiving area of the position sensing device 53 .

FIG. 4 is a block diagram of a control system for compensating for camera shake or image blur.

The anti-shake driving mechanism 40 includes first and second yokes 35 , first magnets 36 and second magnets 37 , and first coils 38 and second coils 39 . Control of power supplied to the coils 38 and 39 is controlled by a controller (CPU) 61 . That is, the imaging device 23 is moved by electromagnetic power generated by the supply of electric power to the coils 38 and 39, so that the controller 61 performs camera shake compensation.

In order to obtain the position of the imaging device 23 for camera shake compensation, a position calculation processor 62 is provided. The position calculation processor 62 receives position signals from the position sensing device 53 relating to the relative position of the imaging device 23 in relation to the fixation member 31 . The position calculation processor 62 controls the on/off states of the LEDs 52a-52i according to the position signal. On/off control of the LEDs will be described later.

According to the position signal obtained by the position sensing device 53 and the on/off state of the LEDs 52a-52i, the position calculation processor 62 calculates the relative position of the imaging device 23 or the housing 21 corresponding to the fixing member 31. The position data representing the relative position is transmitted to the controller 61 and the controller 61 calculates the amount by which the imaging device 23 should move according to the position data, thereby controlling the anti-shake driving mechanism 40 .

An execution component 63 is connected to the controller 61 . Referring to FIG. 1 , the operating component 63 is provided on the camera body 11 , and the camera shake compensation is turned on or off by operating the operating component 63 .

Referring to FIGS. 5 and 6 , the detection operation of the relative position corresponding to the fixing member 31 will be described.

As shown in FIG. 5, nine LEDs 52a-52i are separately distributed on the position sensing device and each emits concentrated light perpendicular to the light receiving area 53a of the position sensing device 53. The light receiving area 53a, for the position sensing device 53 to detect concentrated light, has a rectangular shape and its size is smaller than the area surrounded by the eight LEDs 52a-52d arranged around the LED 52e, and 52f-52i. In particular, the distance between two adjacent LEDs (for example, the distance between the LED 52a and the LED 52b, and the distance between the LED 52a and the LED 52b) is shorter than the side length of the light receiving area 53a. That is, the size (area) of the rectangle "S1" is formed by the four LEDs 52a, 52b, 52d, and 52e arranged in the upper left area in FIG. Concentrated light emitted by 52b, 52d and 52e can be simultaneously received at the four corners of the light receiving area 53a.

As shown in FIG. 5, in an initial state, the light emitting unit 52 is arranged at the position of the centrally positioned LED 52e coincident with the center of the light receiving area 53a of the position sensing device 53. In this state, only LED 52e is turned on and the others are turned off. When the movable member (that is, the casing 21, the imaging device 23, the coil printed circuit board 24, etc.) is moved, the receiving position of the condensed light on the light receiving area 53a is displaced, and the position signal representing the light receiving position is given by The position sensing device 53 outputs.

In the controller 61 (refer to FIG. 4 ), the relative position of the movable member corresponding to the fixed member 31 is obtained according to the position signal. When the center LED 52e is positioned in the center area corresponding to approximately the light receiving area 53a, the position signal directly corresponds to the relative position of the movable member corresponding to the fixed member 31. That is, in this state, the relative position can be obtained by using only the concentrated light emitted from the center LED 52e.

When the position sensing device 53 is relatively moved to the right from the position in FIG. The generated position signal judges that the right LED 52f has reached the position corresponding to the receiving area 53a, and then turns on the right LED 52f. That is, the spotlight from the center LED 52e irradiates to the left of the receiving area 53a and the spotlight from the right LED 52f irradiates to the right of the receiving area. More specifically, the controller 61 turns on and off the center LED 52e and the right LED 52f alternately.

That is, as shown in FIG. 7, when the relative movement of the movable member is small, only the center LED 52e (light source "A") is continuously turned on (refer to FIG. 7, signal timing labeled (a)). On the other hand, when the right LED 52f (light source "B") is also turned on, the LED 52e is alternately turned on with the same period as the LED 52f (refer to FIG. 7, signal timing labeled (b)). Due to the flashing spotlight of the LED 52e and the LED 52f, the position calculation processor 62 determines that the LED 52e and the LED 52f are located on both sides of the light receiving area 52a.

When the position sensing device 53 is relatively moved further to the right, and when the left side of the light receiving area 53a is located on the right side of the center LED 52e, the center LED 52e is turned off and only the right side LED 52f is continuously turned on. The position calculation processor 62 calculates the relative position of the movable member corresponding to the fixed member 31 based on the position signal due to the spotlight from the right LED 52f. That is, the calculation is performed based on the light-receiving position represented by the position signal and the displacement and direction of motion when the position sensing device 53 moves to the position of the LED 52f. For example, when the position sensing device 53 moves horizontally and relatively to the right with respect to each of the LEDs in FIG. The vector (vector) is then added to the position vector represented by the position signal due to the condensed light of the LED 52f.

When the movable member is configured so that it can be relatively rotated with respect to the fixed member 31, the three LEDs (light sources A, B and C) are turned on and off, as shown on the right hand side of FIG. 7 (reference mark (c) signal timing). In this case, each of the three LEDs alternately turns on and off with the same cycle. That is, only one of the LEDs is turned on at the same time.

As shown in FIG. 5, when the position sensing device 53 moves relatively to the lower right, and when the upper left corner of the light receiving area 53a reaches the position of the lower right LED 52i (refer to the square "S2" in FIG. 5), this situation represents Limitation of the detection area on the lower right side of the position sensing device 53 . That is, although the conventional detection zone "Z1" is limited to a distance from the LED 52e to a position where the LED 52e corresponds to one side of the light-receiving region 53a of the position sensing device 53, according to the present embodiment, the detected The distance or position is expanded from LED 52e to a position corresponding to one side surrounding LEDs 52a-52d and 52f-52i such that the detection zone "Z2" is doubled in distance and quadrupled in area.

As described above, according to the present embodiment, the position detection area is enlarged without using any particularly large area sensor (a position sensing device), and a usual low-priced two-dimensional square area sensor such as Square area sensor with side length 2mm.

Also, in this embodiment, the LED is turned off when it cannot radiate light onto the position sensing device, and it flashes at the initial stage when the LED is turned on, and at the final stage when the LED is turned off. flash. Therefore, no blank spot or period of light is generated in the detection operation, and the detection is continuously performed even when the LEDs used in detection are switched from one to another. Also, by turning off unnecessary lamps, power consumption can be limited.

Referring to Fig. 8 and Fig. 9, a second embodiment of the present invention will be described. The structure of the second embodiment is basically the same as that of the first embodiment. In the second embodiment, the plurality of LEDs 71a, 71b, and 71c are regularly turned on and off.

For example, LEDs 71a, 71b, and 71c are arranged at positions corresponding to vertices of a triangle, as shown in FIG. 8 . Also, the LEDs 71a, 71b, and 71c are arranged so that concentrated light from all the LEDs 71a, 71b, and 71c is irradiated to the light-receiving area 53a of the position sensing device 53 at the same time. That is, in FIG. 8, when the concentrated light of the lower right LED 71a is irradiated to the lower right corner of the square close to the light receiving area 53a, the concentrated light of the lower left LED 71b is irradiated to the lower left corner of the square close to the light receiving area 53a. , and the concentrated light of the LED 71c on the upper side is irradiated to an area close to the upper side of the light receiving area 53a below the upper edge (edge).

As shown in FIG. 9, all LEDs 71a, 71b and 71c (light sources A, B and C) flash continuously so that normally, light sources C, B and A are turned on periodically and in sequence. When all the concentrated light from the LEDs 71a, 71b and 71c is received by the light receiving area 53a, three position signals are output from the position sensing device 53, thereby obtaining the relative position of the movable member corresponding to the fixed member.

Wherein, the light receiving area 53 a moves relative to a position where the light receiving area 53 a receives three concentrated lights, which is the lower left in FIG. 8 . When the concentrated light of the LED 71c moves out of the light receiving region 53a, based on the timing chart of the flashing timing shown in FIG. 9, the fact that the concentrated light of the LED 71c moves out of the light receiving region 53a is detected. Therefore, when the spotlight 71c moves over the receiving area 52a, only the spotlights of the LEDs 71a and 71b are detected, thereby outputting two position signals and obtaining a movable member corresponding to the fixed member in the same manner as the first embodiment. relative position.

Also, when the condensed light from the LED 71a is squeezed out from the light receiving area 53a, only the condensed light from the LED 71b is detected. Therefore, only one position signal is output from the position sensing device 53 and the relative position of the movable member corresponding to the fixed member is obtained in the same manner as the first embodiment.

It should be noted that the embodiment of the position detection sensor is used to detect the two-dimensional movement of the movable member corresponding to the fixed member 31, however, the present invention can also be used in the case where the movable member only moves in one dimension.

Further, according to the present invention, a plurality of light sources can also be provided on the fixed member, while a position sensing device is provided on the movable member.

Referring to Figs. 10-18, a third embodiment of the present invention can be explained. Fig. 10 is a side view of a position detection system used in a third embodiment of the present invention. Also, FIG. 11 illustrates a light receiving area of a two-dimensional position sensing device (PSD: Position Sensitive Detector) of the position detection system. In the present embodiment, an arrangement for translation and rotation detection of a movable object corresponding to a fixed member on a two-dimensional plane is described.

The movable plate 120 is arranged in parallel with the fixed member 110 and is supported so as to be movable in a direction (X direction) indicated by an arrow in FIG. 10 . And the movable plate 120 is supported so that it can move in a direction (Y direction) perpendicular to the surface of FIG. 10 and so that it can rotate about an axis perpendicular to a plane including the X and Y directions.

A two-dimensional position sensing device (PSD) 111 is fixed on the fixed member 110 such that a receiving area 112 of the position sensing device 111 is parallel to a plane including a trajectory defined by the movement of the movable plate 120 . On the other hand, the light source unit 121 is attached to the movable plate 120 at a position facing the light receiving area 112 of the position sensing device 111 .

Inside the light source unit 121, two light emitting devices such as LEDs 122a and 122b are mounted. In front of each of the LEDs 122a and 122b, that is, on the side of the position sensing device 111, a spot mask 123 is provided. The light spot mask (spot mask) 123 has holes 123a and 123b pierced through the mask 123 so that the concentrated light from the LEDs 122a and 122b can pass through. Each concentrated light emitted by each of the LEDs 122a and 122b is generated with the light receiving area 112 of the position sensing device 111 and forms individual light spots "a" and "b". In the third embodiment, the LEDs 122a and 122b are alternately turned on and off at the same interval, as shown in the timing diagram 12, so that the light spot "a" of the LED 122a and the light spot "b" of the LED 122b are alternately in the light receiving area 122 were detected.

Fig. 13 is a block diagram showing a schematic circuit diagram of a position detection system of a third embodiment. LEDs 122a and 122b are controlled to turn on and off by computing processor 141 of drive circuits 143a and 143b. From the output terminals 113a, 113b, 113c and 113d, the position sensing device 111 outputs a position signal (current signal) corresponding to the light spot "a" or the light spot "b" formed when the LED 122a or LED 122b is turned on. Location. The position signal from each output terminal 113a - 113d is input to the calculation processor 141 . Based on these four outputs, the calculation processor 141 obtains the positions of the light spots "a" and "b" on the light receiving area 112, thereby calculating the position in the X direction and the position in the Y direction or coordinates (x, y). Also, the computing processor 141 detects the positions of at least two pairs of light spots "a" and "b", which are irradiated on the light receiving area 112 at certain time intervals, and stores them in a built-in memory. The calculation processor 141 calculates the rotation direction, position and angle of the LEDs 122a and 122b according to the above two pairs of position data.

In FIG. 11, the light spots "a" and "b" of the LEDs 122a and 122b in the initial state are represented by white circles "a0" and "b0". The coordinates of the light point "a0" are expressed as (x _a0 , y _a0 ), and the coordinates of the light point "b0" are expressed as (x _b0 , y _b0 ). The movable plate 120 is moved by turning from the above-mentioned initial state, and thus the light spots "a0" and "b0" of the LEDs 122a and 122b move to the light spots "a1" and "a2" of the light receiving area 112. Also, the coordinates of the light point "a1" are expressed as (x _a1 , y _a1 ) and the coordinates of the light point "b1" are expressed as (x _b1 , y _b1 ). These are derived based on the output from the position sensing device 111 .

From the coordinates (x _a0 , y _a0 ) and (x b0 , y b0 ) of the light points "a0" and "b0" and the coordinates (x _a1 , y _a1 ) and (x _b1 , y _b1 ) of "a1" and " _b1 " _b1 ), the distance ΔX between the light points "a0" and "a1" on the X direction can be obtained, and the distance ΔY on the Y direction, between the light points "a0" and "b0" on the X direction (or between The distance "L" between the light spots "a" and "b"), and the distance ΔL between the light spots "a1" and "b1" in the X direction. Also, the rotation angle θ of the movable plate 120 can be obtained by substituting the distances "L" and "ΔL" in Equation 1 below.

$\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; COS</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\frac{\mathrm{<span\; class="notranslate">\; \&Delta;\; L</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}$

As described above, according to the third embodiment, not only the position of the movable plate 120 in the X and Y directions but also the direction, position and rotation angle θ of the movement of the movable plate 120 can be detected. It should be noted that the movable plate 120 moves within a range in which concentrated light from the LEDs 122a and 122b is generated along with the light receiving area 112 and each forms light spots "a" and "b".

In this embodiment, the position sensing device 111 is connected to the fixed member 10 and the light source unit 121 is connected to the movable plate 120 . However, in an alternative embodiment not shown, the light source could be attached to the fixed member and the position sensing means could be attached to the movable plate.

Also, in this embodiment, although only two LEDs 122a and 122b are provided as light emitting devices, the number of light emitting devices may be two or more than two.

Next, the application of the two-dimensional position detection system of the present invention will be explained. Figures 14 to 18 illustrate an embodiment in which the position detection system shown in Figures 10-13 is an anti-shake device for a digital camera that compensates for camera shake by moving the imaging device.

Fig. 14 is a cross-sectional view of a digital camera provided with an anti-shake device including the position detection system of the present invention. A digital camera (main body) 201 is provided with a photographing lens 203 including a plurality of lenses "L1", "L2", and "L3". The imaging device 205 is disposed behind the last lens "L3". An image of a subject is projected on an imaging surface of an imaging device 205 through a photographic lens 203 . The imaging device 205 is supported by the anti-shake device so that the optical axis "O1" of the taking lens 203 passes through the center of the imaging surface vertically, and the imaging device 205 is arranged on the focal plane of the taking lens 203.

The anti-shake device includes a fixed member 210, which is fixedly connected to a digital camera 201, and a coil printed circuit board 220 (a movable stage or a movable plate), which is mounted on an axis perpendicular to the optical axis "O1" of the photographing lens. It is rotatably supported on a plane and moves relative to the fixed plate 210 . The imaging device 205 is provided on the coil printed circuit board 220 . Moreover, the light source unit 121 and the position sensing device 111 of the position detection system are used to detect the position and rotation angle of the imaging device 205 and are connected to the coil printed circuit board 220 and the fixing member 210 .

Further, the digital camera 201 is provided with an angular velocity sensor, such as a vertical angular velocity sensor 145V and a horizontal angular velocity sensor 145H, to detect the shake of the digital camera 201 or more specifically the shake of the optical axis “O1” of the photographing lens 203. Fig. 15 is a block diagram showing a schematic circuit diagram of an anti-jitter driving system. In addition to the position detection system illustrated in Figure 13, the anti-shake drive system also provides vertical and horizontal angular velocity sensors 145V and 145H, used to drive three drive coils CY, CX1 and CX2 of the stage, and drivers 147a, 147b and 147c, which provide power to each drive coil CY, CX1 and CX2.

The vertical angular velocity signal and the horizontal angular velocity signal, which are detected by the vertical and horizontal angular velocity sensors 145V and 145H, are input to the calculation processor 141, so that the calculation processor 141 calculates the imaging device 205 according to the vertical and horizontal angular velocity signals. The direction, speed, and displacement of the movement of the object to eliminate the relative movement of the image of the object projected on the imaging surface through the photographic lens 203 corresponding to the imaging surface. Thus, the calculation processor 141 supplies current to the driving coils CY, CX1 and CX2 according to the calculation results to move the coil printed circuit board 220 . At this time, the computing processor 141 turns on the LEDs 122 a and 122 b alternately, and inputs a position signal from each terminal 113 a - 113 d of the position sensing device 111 . The calculation processor 141 further calculates the position and rotation angle of the coil printed circuit board 220, and controls the power supply to the driving coils CY, CX1 and CX2.

Referring to FIG. 16 to FIG. 18 , the mechanical structure of the anti-shake device of this embodiment will be further described.

The coil printed circuit board 220 is supported on the fixing member 210 so as to be able to move and rotate in any direction, but it always maintains the same plane. The imaging device 205 is connected to the front of the coil printed circuit board 220 (the side of the imaging object) through the base 230 . On the front surface of the base 230, a rectangular parallelepiped housing 231 is attached. A rectangular window 231 a is formed on the front surface of the housing 231 . The shape and size of the window 231a are formed so that it is not necessary to trim the subject image projected by the photographing lens 203 on the imaging surface of the imaging device 205 .

The optical low-pass filter 233 is arranged inside the housing 231 such that the optical low-pass filter 233 abuts against a frame forming the window 231a. Between the optical low-pass filter 233 and the periphery of the imaging surface of the imaging device 205 , there is provided a pushing member 234 that seals the space between the optical low-pass filter 233 and the imaging device 205 (imaging surface).

The housing 231 passes through the window 210a formed in the fixing member 210 without contact. The size of the window 210a is defined as the outermost limit of the movable area of the housing 231 in the anti-shake operation, and is larger than the range required for the housing 231 to move in the anti-shake operation.

Flanges 232 protrude from all sides of the housing 231 , which are fixedly connected to the base 230 such that the flanges 232 cover the periphery of the outer edge of the window 210 a of the fixing member 210 . Between each corner of the flange 232 of the housing 231 and the fixing member 210, a support, such as a spherical support 213, is arranged so that the support flange 232 can move freely in any direction on a desired plane while being held on the retaining flange 232. The distance from the fixing member 210 is constant.

Each corner behind the flange is exposed such that the push shaft biased by the spring 216 contacts the flange 232 . The tip of the push shaft 215 that contacts the flange 232 is made of a material that has low static and low sliding friction relative to the flange 232 .

Due to the action of the ball support 213 and the push shaft 215 , relative movement between the housing 231 and the fixed member 210 is enabled due to the rolling of the ball support 213 within the flange 232 of the fixed member 210 . Therefore, the casing 231 is supported, and can be moved and turned in any direction.

In the above-mentioned embodiments, the fixing member 210 and the flange 232 where the spherical support 213 contacts are both set as horizontal planes. However, one of the surfaces can also be configured to have a hemispherical concave hollow which receives the spherical support 213 so that the spherical support 213 rolls inside the hollow.

Many wires are printed on the coil printed circuit board 220 (which is omitted in the drawing), and these wires are electrically connected to the terminal of the imaging device 205 . The coil printed circuit board 220 is provided with four rectangular extended board members 220 a , 220 b , 220 c and 220 d extending outward from a central section connecting the floor 230 and the imaging device 205 . At the rear of each rectangular extended plate member 220a, 220b, 220c, a helical sheet coil pattern is printed, such as the X-direction drive coil "CX", and the first and second Y-direction drive coils "CY1" and "CY2" "."

The light source unit 121 is placed on the front surface of the remaining rectangular extended plate member 220d. The wires of the LEDs 122a and 122b are connected to corresponding wires of the coils printed on the circuit board 220. On the fixing member 110 , the position sensing device 111 is connected at a position facing the light source unit 121 . The configurations of the light source unit 121 and the position sensing device 111 are the same as those described in FIG. 10 .

It should be noted that the wires of each coil printed on the circuit board 220 are connected to a fixed printed circuit board inside the digital camera 201 through a flexible printed circuit board (not shown), so as not to disturb the coils printed on the circuit board. translation and rotation of the coil.

As shown in FIG. 16, the Y-direction drive coil "CY" and the first and second X-direction drives "CX1" and "CX2" form a rectangular spiral with linear sides. Conveniently, the drive coils "CY", "CX1" and "CX2" are represented by lines wound several times. In fact, the wire is wound dozens of times. Each end from the driving coils "CY", "CX1" and "CX2" is connected to the driver 147a, 147b, 147c through a wire printed on the coil printed circuit board 220, a flexible printed circuit board or the like.

At the rear of the fixing member 210, "YY", "YX1", "YX2", which have a U-shaped section profile and are formed from a magnetic substance such as a steel plate, are fixedly connected to each of three positions. Magnets "MX" and "MY" are fixed on each of the yokes "YY", "YX" and "YX", which are fixed on the inner surface of each yoke near each tip. The magnet "MY" of the yoke "YY" is arranged so that the N pole and the S pole are aligned in the X direction. The magnets "MX1" and "MX2" of the yokes "YX1" and "YX2" are arranged so that N poles and S poles are aligned in the Y direction. Each of the yokes "YX1" and "YX2" faces the respective magnets "MX1" and "MX2" such that a space between the yokes and the magnets creates a magnetic field region, which is a region where lines of magnetic force are concentrated. Likewise, a magnetic circuit is created in which the lines of force are concentrated in the space between the yoke and the magnet. The rectangular extension plate members 220b and 220c are inserted between the yokes "YX1", "YX2" and the magnets "MX1" and "MX2" without contact. Also, a rectangular extension plate member 220a is inserted between the yoke "YY" and the magnet "MY" without contact. Thus, each extension plate member 220a, 220b, and 220c is disposed in the space between the yoke and the magnet, is movable in the X direction and the Y direction, and rotates on the X-Y plane.

When electricity is supplied to one of the driving coils "CY", "CX1", and "CX2", the imaging device 205, the coil printed circuit board 220, and the base 230 move in the same direction. When power is supplied to two of the driving coils (for example, driving coils "CX1" and "CX2"), the coil printed circuit board 220 is to be rotated when the respective driving coils are to move in opposite directions. In addition to the above-described operations, if power is further supplied to the driving coil "CY", the coil printed circuit board 220 moves in the X direction while rotating. That is, depending on the combination of the power supplied to the driving coils "CY", "CX1" and "CX2", the coil printed circuit board 220 can move in the X direction and the Y direction, and can also rotate, either separately or simultaneously.

In the anti-shake device of this embodiment, based on the vertical and horizontal angular velocities detected by the angular velocity sensors 145V and 145H, the calculation processor 141 calculates the velocity and displacement in the X direction and the Y direction, thereby, by To control the power supplied to each of the driving coils "CY", "CX1" and "CX2" and translation, the coil printed circuit board 220 is translated and rotated in the X direction and the Y direction. When the coil printed circuit board 220 is moved and rotated, the light spots "a" and "b" illuminated on the light receiving area of the position sensing device 111 are also moved, thereby changing the output from the position sensing device 111 Signals at terminals 13a, 13b, 13c and 13d. The calculation processor 141 calculates the position and rotation of the coil printed circuit board 220 based on the detected position signal, and controls power supplied to each of the driving coils "CY", "CX1", and "CX2".

In the third embodiment, because the position detection system includes two light-emitting devices for detecting the position of the coil printed circuit board 220, it can not only detect the translation of the coil printed circuit board 220 in two vertical directions, but also Check its rotation. Therefore, image blur caused by rotation about the optical axis can also be compensated, as well as camera shake in the horizontal or vertical direction.

Although the embodiments of the present invention have been described herein with reference to the accompanying drawings, it is obvious that many modifications and changes can be made to the present invention by those skilled in the art without departing from the scope of the present invention.

Claims (15)

1. A position detection system for detecting the position of a movable member corresponding to a fixed member, comprising: a plurality of light sources provided on one of the fixed member or the movable member and emitting concentrated light; a position sensing device, which is provided on the other of the fixed member or the movable member and receives the concentrated light, and further outputs a position signal corresponding to the relative position according to the received position of the concentrated light; a light source controller that controls on/off states of the plurality of light sources; Wherein when the position sensing device only detects the concentrated light from one of the plurality of light sources, the light source controller continuously turns on one of the light sources, and when the position sensing device detects the spotlight from the plurality of light sources When focusing on two or more light sources among the plurality of light sources, the light source controller causes two or more light sources among the plurality of light sources to flash. 2. The position detection system according to claim 1, wherein the light source controller controls on/off states of the plurality of light sources according to the position signal. 3. The position detection system according to claim 1, wherein said plurality of light sources are arranged in an area larger than a light receiving area of said light sensing means which detects said concentrated light. 4. The position detection system according to claim 1, wherein a distance between said plurality of light sources can be smaller than a width of a light receiving area of said light sensing device which detects said concentrated light . 5. The position detection system according to claim 4, wherein when the spotlight from one of the plurality of light sources shines on one side of the receiving area, the spotlight from another one of the plurality of light sources shines on a side of the receiving area. the other side of the receiving area. 6. The position detection system according to claim 1, wherein said position sensing means comprises a two-dimensional area sensor; 7. The position detection system according to claim 6, wherein a light receiving area for detecting said spotlights in said position sensing device has a rectangular shape, and four spotlights can be detected at four corners of the light receiving area. Simultaneous detection. 8. The position detection system according to claim 1, wherein said plurality of light sources are flashed such that only one of said plurality of light sources is turned on at a time. 9. The position detection system according to claim 8, wherein two light sources of said plurality of light sources can alternately flash with the same period. 10. The position detection system according to claim 1, wherein the plurality of light sources are flashed such that three or more light sources among the plurality of light sources are sequentially turned on. 11. The position detection system according to claim 1, further comprising a position calculator capable of calculating relative positions according to on/off states of the plurality of light sources. 12. A position detection system for detecting the position of a movable member corresponding to a fixed member, comprising: a plurality of light sources provided on one of the fixed member and the movable member and emitting concentrated light; a position sensing device which is provided on the other of the fixed member and the movable member and receives concentrated light, and which further outputs a position signal corresponding to a relative position according to a position of the received concentrated light; as well as a light source controller that controls on/off states of the plurality of light sources; Wherein the light source controller flashes each of the plurality of light sources so that each of the light sources is turned on in sequence. 13. A position detection system comprising: a movable member that moves on a two-dimensional plane relative to the fixed member; a light source unit that is provided on one of the fixed member and the movable member, and the light source unit includes a plurality of light emitting devices that are separated by a predetermined distance; position sensing means, which is provided on the other of the fixed member and the movable member, receives light from said light source and detects a position of said received light; a light source controller selectively turns on one of the plurality of light emitting devices in a predetermined order; and a calculator that calculates the direction of movement, displacement, and rotation of the movable member based on two pairs of position data, wherein a pair of position data indicates a position at which light from a pair of light emitting devices is detected, and the other pair of position data detects denotes a position at which light from the pair of light-emitting devices is detected at a predetermined time interval after detection of the pair of position data. 14. The position detection system according to claim 13, wherein the number of the plurality of light emitting devices can be two, and the light source controller alternately turns on the two light emitting devices at the same cycle. 15. The position detection system according to claim 13, wherein the movable member is rotatably supported relative to the fixed member.

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