JP4511879B2 - Electronic zoom operation mechanism and optical instrument equipped with the operation mechanism - Google Patents

Description

  The present invention relates to an electronic zoom operation mechanism of an optical instrument, and more particularly to an electronic zoom operation mechanism capable of performing an electronic zoom operation by an operation similar to the optical zoom operation and an optical instrument including the electronic zoom operation mechanism.

  Conventionally, zoom operations of optical instruments such as projectors and cameras have been performed by optical zoom in which a lens is manually operated, and power zoom in which a lens is operated using a drive motor instead of manual operation is also increasing. However, in the optical zoom, when trying to realize a zoom with a high magnification, the lens becomes complicated and large. For this reason, recently, an electronic zoom called a digital zoom for setting a zoom by electronically enlarging / reducing a digital image has been used, and is also used in combination with an optical zoom.

  Until now, the electronic zoom operation has been provided with two operation buttons such as WIDE and TELE, and the zoom operation is performed by pressing these buttons. A conventional electronic operation mechanism of an electronic zoom will be described with reference to FIG. FIG. 8 is a schematic block diagram showing an example of a conventional electronic zoom operation mechanism. The electronic zoom operation mechanism 130 outputs the WIDE zoom key 131 for operating the zoom to the wide angle side, the TELE zoom key 132 for operating the telephoto side, the CPU 143 that is the central processing unit, and the count for instructing the enlargement or reduction of the image to the image control unit 123. A scaler 144 which is a counting circuit is included. As for the electronic zoom operation, when the user presses the WIDE zoom key 131 and the TELE zoom key 132, the operation is input to the video zoom processing unit 134, and the CPU 143 detects the time or the number of times the zoom key is pressed, and the value thereof. Based on the above, the scaler 144 controls the image control unit 123 to perform a zoom operation digitally.

  However, such a conventional electronic zoom operation has the following problems. The first problem is that a user who has been accustomed to an optical zoom operation that performs a zoom operation by rotating the rotary zoom lens mechanism so far has provided two operation buttons and performs a zoom operation by pressing these buttons. Therefore, the operation method is different from the conventional one, and the user feels uncomfortable when using it.

  The second problem is that two operation buttons are provided and the zoom operation is performed by pressing these buttons. Therefore, when developing products with the same lineup of optical zoom, it is possible to share the lens barrel and housing. That is not possible.

In optical zoom, a zoom lens barrel has been disclosed in which power focus / power zoom is close to a manual operation feeling and can perform high-precision power focus / power zoom with high operability. Here, an operation ring is provided that can move in the optical axis direction and rotate around the optical axis in a state of being engaged with a lens fixing tube, and a magnetizing rod having a magnetized portion on an outer peripheral surface that rotates in conjunction with the operation ring. For the power zoom operation corresponding to the rotating state of the operating ring by detecting the change in the magnetic field from the magnetized part when the operating ring state detecting unit provided and positioned on the fixed cylinder rotates the rod by rotating the operating ring (See Patent Document 1).
JP-A-6-230265

  However, in the zoom lens barrel described in Patent Document 1, it is possible to rotate in a narrow gap between the fixed cylinder and the operation ring in conjunction with the operation ring, and alternate between the N pole and the S station along the circumferential direction. It is necessary to provide a magnetized lot having a magnetized part formed with a magnetic ring and an operating ring state detecting part having a magnetoresistive element positioned on a fixed cylinder for detecting the magnetism of the magnetized part. It has become a structure. It is also difficult to achieve a power zoom by simply adding an electronic operation to such an optical lens zoom mechanism.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic zoom operation mechanism having a simple structure in which a zoom operation can be performed in the same manner as the operation of an optical zoom, and can be shared with an optical zoom as a member, and an optical instrument including the operation mechanism Is to provide.

The electronic zoom operation mechanism of the present invention is
An electronic zoom operation mechanism for controlling an electronic zoom of an optical instrument having a lens, a rotating member, a magnetic body fixed to the rotating member and moving in the rotating direction of the rotating member, and a predetermined vicinity in the vicinity of the moving range of the magnetic body A magnetic sensor fixed at the position; and a video zoom processing unit that calculates a rotation angle of the rotating member from an output value of the magnetic sensor and outputs a control value of an electronic zoom corresponding to the calculated rotation angle.

Two magnetic sensors are provided along the moving direction of the magnetic body, and the image zoom processing unit may calculate the rotation angle of the rotating member from the output values of the two magnetic sensors and the sum thereof. If the sum of the output values of the two magnetic sensors, becomes maximum when the middle position of the two magnetic sensors is a magnetic material, the position of the magnetic sensors so as to decrease smoothly in response to the position of the magnetic body It is preferable that the gain is adjusted. Further, the rotating member may rotate on the outer periphery of the lens barrel of the lens.

  An optical instrument having the lens of the present invention includes the above-described electronic zoom operation mechanism, and the projector of the present invention also includes the above-described electronic zoom operation mechanism.

  In the present invention, since the operation of the electronic zoom can be performed by the operation ring in the same manner as the operation of the optical zoom, it can be performed similarly to the operation of the optical zoom when used by the user. The housing can also be shared when developing products with the same lineup of optical zoom.

  The first effect of the present invention is that the rotational movement is converted into an electrical value by a magnetic sensor and detected, and the electronic zoom is controlled. Therefore, the electronic zoom operation is similar to the optical zoom operation. It is possible for an operator who is able to perform the operation and is not familiar with the optical zoom.

  The second effect is that by providing two magnetic sensors, the detection width can be expanded and the operation accuracy can be increased.

  The third effect is that since an operation ring similar to the operation ring of the optical zoom is used, the lens barrel and the case can be shared when developing a product having the optical zoom in the same lineup.

  The present invention is characterized in that, in an operation method of an electronic zoom operation mechanism provided in an optical instrument having a lens group such as a projector, electronic control of the electronic zoom can be performed by the same operation method as the optical zoom. .

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a projector provided with an electronic zoom operation mechanism according to an embodiment of the present invention. Here, the optical apparatus will be described as a projector, but the present invention is not limited to a projector, and can be widely applied to optical apparatuses that handle digital images, such as digital cameras and movie cameras. 2A and 2B are partial schematic views of the projector showing the configuration of the electronic zoom operation mechanism according to the first embodiment of the present invention. FIG. 2A is a partial side sectional view of the vicinity of the projection lens, and FIG. FIG. 3 is a partial front sectional view, and FIG. 3 is a control system diagram of the electronic zoom operation mechanism showing the control function of the electronic zoom operation mechanism according to the first embodiment of the present invention.

  As shown in FIG. 1, the projector 10 includes a projection device 20 having a projection lens 21 and a display unit 22, an image control unit 23 that controls an image on the display unit 22, and a predetermined zoom on the image control unit 23. An electronic zoom operation mechanism 30 for instructing output of an enlarged / reduced image, a video input unit 24, and a central processing unit 60 for controlling the overall operation are provided.

  As shown in FIGS. 1 and 2, the electronic zoom operation mechanism 30 is fixed to the operation ring 31 and the operation ring 31 that is rotatably disposed on the outer surface of the lens barrel 25 surrounding the lens group of the projection lens 21. The magnetic body 32 that moves in the rotational direction in response to the rotational movement of the operation ring 31, the magnetic sensor 33 that is fixed to the printed circuit board 35 inside the projector 10 in the vicinity of the rotational path of the magnetic body 32, and the magnetic sensor And a video zoom processing unit 34 that receives the signal 33 and outputs an instruction to the image control unit 23 to zoom in / out the input video. In the first embodiment, the magnetic sensor 33 includes a first magnetic sensor 33a and a second magnetic sensor 33b arranged at a predetermined interval. Here, the magnetic body 32 may be a permanent magnet or an electromagnet, and the magnetic sensor 33 may be any element that can convert magnetism into voltage, and a Hall element or a magnetoresistive element can be used.

  The video input from the video input unit 24 and zoomed by the image control unit 23 is projected from the display unit 22 through the projection lens 21 onto the projection surface 70 as a projection image. The projected image is adjusted as an image from wide angle (WIDE) to telephoto (TELE) by the electronic zoom operation mechanism 30.

  Next, the operation of the electronic zoom operation mechanism of the first embodiment will be described with reference to FIGS. The operation ring 31 has a shape similar to an operation ring called an optical zoom cam cylinder, and can be rotated from the outside of the casing 11 of the projector 10. For example, when the operation ring 31 is rotated via the knob 31a, the magnetic body 32 fixed to the operation ring 31 moves integrally with the operation ring 31 in the rotation direction. As schematically shown in FIG. 3, the magnetic body 32 fixed on the operation ring 31 includes the first magnetic sensor 33 a and the second magnetic sensor 33 a fixed to the printed circuit board 35 by the rotation of the operation ring 31. The positional relationship with the magnetic sensor 33b changes. That is, the detection values detected by the first magnetic sensor 33 a and the second magnetic sensor 33 b differ depending on the rotational position of the operation ring 31. This change is detected and an electronic zoom operation is performed. In this way, in the present invention, since the rotational motion of the operation ring 31 can be detected by the magnetic sensor 33 and converted into an electrical value, the electronic zoom operation can be performed in the same manner as the optical zoom operation. In the first embodiment, two magnetic sensors are provided to increase the movement width of the magnetic material that can be detected and the accuracy of the control is increased. However, as shown in the second embodiment, the magnetic sensor, the magnet, Depending on the positional relationship, a single sensor may be used.

  FIG. 4 is a graph showing the relationship between the detection voltage detected by the first magnetic sensor 33a and the second magnetic sensor 33b and the operation ring position. The broken line is the detection voltage of the first magnetic sensor 33a, the chain line is the detection voltage of the second magnetic sensor 33b, and the solid line is the sum of the detection voltage of the first magnetic sensor 33a and the detection voltage of the second magnetic sensor 33b. is there. FIG. 4 shows that the position of the operation ring 31 can be calculated from the detection voltage of the first magnetic sensor 33a and the detection voltage of the second magnetic sensor 33b.

  The video zoom processing unit 34 shown in FIG. 3 shows a block diagram of an electric circuit that converts the detection voltage of the magnetic sensor 33 into an electronic zoom operation. Here, the case where the magnetic sensor 33 is a sensor that outputs a voltage will be described as an example. The voltage detected by the first magnetic sensor 33a is detected and amplified as a potential difference by the first differential amplifier 41a. The potential difference output from the first differential amplifier 41a is converted into a digital signal by the first A / D converter 42a. The signal digitally converted by the first A / D converter 42 a is input to the CPU 43. Similarly, the voltage detected by the second magnetic sensor 33b is similarly input to the CPU 43 through the second series of circuits. In the CPU 43, the calculation described later is performed, the rotation angle of the operation ring 31 is detected, the scaler 44 is controlled based on the value, and the output of the scaler 44 is input to the image control unit 23 to digitally zoom the video. Control is performed.

  The following example is conceivable as a calculation method for detecting the rotation angle of the operation ring 31 described above. As a premise, the added value of the first magnetic sensor 33a and the second magnetic sensor 33b at the same operation ring position is always larger than the detection value of each magnetic sensor, and the first magnetic sensor 33a and the second magnetic sensor The interval and the gain of the magnetic sensor 33 are adjusted so that the curve becomes a maximum in the middle of the sensor 33b and the voltage changes smoothly (see the detected voltage addition value 53 in FIG. 4). Thereby, the rotation angle of the operation ring 31 can be detected with high accuracy.

  The detection potential difference on the first magnetic sensor 33a side and the detection potential difference on the second magnetic sensor 33b side are added. When this added value is larger than the maximum value of each magnetic sensor, the magnetic body 32 of the operation ring 31 is located between both magnetic sensors or near the peak of both magnetic sensors.

In this case, the detected voltage difference between the first magnetic sensor 33a and the second magnetic sensor 33b is taken, and the position of the operation ring 31 is determined based on the difference. That is, in FIG.
1) When (detection voltage of the first magnetic sensor 33a) − (detection voltage of the second magnetic sensor 33b)> 0, it is on the WIDE side.
2) (Detection voltage of the first magnetic sensor 33a) − (detection voltage of the second magnetic sensor 33b) = 0.
3) If (detection voltage of the first magnetic sensor 33a) − (detection voltage of the second magnetic sensor 33b) <0, it is on the TELE side.
4) When the value is smaller than the maximum value of each magnetic sensor, the position of the operation ring 31 is located on the WIDE end and the TELE end side beyond the vicinity of the peak of each magnetic sensor.

  In this case, the position of the operation ring can be determined from the detection value of each sensor. It is effective to calibrate the maximum value and the addition value of both sensors in advance and correct them in the CPU 43 based on the state at the time of calibration.

  Next, a second embodiment of the present invention will be described with reference to the drawings. 5A and 5B are partial schematic views of a projector showing the configuration of the electronic zoom operation mechanism according to the second embodiment of the present invention. FIG. 5A is a partial side sectional view in the vicinity of the projection lens, and FIG. FIG. 6 is a partial front sectional view, and FIG. 6 is a control system diagram of the electronic zoom operation mechanism showing a control function of the electronic zoom operation mechanism according to the second embodiment of the present invention.

  Since the two magnetic sensors provided in the first embodiment are the same as those in the first embodiment except for one in the second embodiment, the same configuration and operation elements are the same. Reference numerals are assigned and description is omitted. FIG. 7 is a graph showing the relationship between the detection voltage detected by the magnetic sensor 83 and the operation ring position. As shown in FIG. 7, the detection voltage of the magnetic sensor 83 and the operation ring position have a correlation, indicating that the position of the operation ring 31 can be calculated from the detection voltage of the magnetic sensor 83. In the second embodiment, the detection range of the magnetic sensor 31 relative to the operation ring 31 is reduced, but the number of sensors can be reduced.

1 is a schematic configuration diagram of a projector provided with an electronic zoom operation mechanism according to an embodiment of the present invention. It is a partial schematic diagram of a projector showing the configuration of the electronic zoom operation mechanism of the first embodiment of the present invention. (A) is a partial side sectional view of the vicinity of the projection lens. (B) is a partial front sectional view of the vicinity of the projection lens. It is a control system diagram of the electronic zoom operation mechanism showing the control function of the electronic zoom operation mechanism of the first embodiment of the present invention. It is a graph which shows the relationship between the detection voltage detected with a 1st magnetic sensor and a 2nd magnetic sensor, and an operation ring position. It is a partial schematic diagram of a projector showing a configuration of an electronic zoom operation mechanism of a second embodiment of the present invention. (A) is a partial side sectional view of the vicinity of the projection lens. (B) is a partial front sectional view of the vicinity of the projection lens. It is a control system diagram of the electronic zoom operation mechanism showing the control function of the electronic zoom operation mechanism of the second embodiment of the present invention. It is a graph which shows the relationship between the detection voltage detected with a magnetic sensor, and an operation ring position. It is a typical block block diagram which shows an example of the operation mechanism of the conventional electronic zoom.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Projector 11 Housing | casing 20 Projection apparatus 21 Projection lens 22 Display part 23, 123 Image control part 24 Image | video input part 25 Lens tube 27 Projection optical axis 30, 130 Electronic zoom operation mechanism 31 Operation ring 31a Knob 32 Magnetic body 33, 83 Magnetic Sensor 33a First magnetic sensor 33b Second magnetic sensor 34, 134 Video zoom processing unit 35 Printed circuit board 41a First differential amplifier 41b Second differential amplifier 42a First A / D converter 42b Second A / D converter 43, 143 CPU
44, 144 Scaler 51 Detection voltage of first magnetic sensor 52 Detection voltage of second magnetic sensor 53 Addition value of detection voltage 54 Detection voltage of magnetic sensor 60 Central processing unit 70 Projection surface 131 WIDE zoom key 132 TELE zoom key

Claims (5)

An electronic zoom operation mechanism for controlling an electronic zoom of an optical instrument having a lens,
A rotating member;
A magnetic body fixed to the rotating member and moving in the rotational direction of the rotating member;
A magnetic sensor fixed at a predetermined position near the moving range of the magnetic material;
A video zoom processing unit that calculates a rotation angle of the rotating member from an output value of the magnetic sensor and outputs a control value of an electronic zoom corresponding to the calculated rotation angle;
Two magnetic sensors are provided along the moving direction of the magnetic body,
The electronic zoom operation mechanism, wherein the video zoom processing unit calculates a rotation angle of the rotating member from output values of two magnetic sensors and a sum thereof. The sum of the output values of the two magnetic sensors is maximized when the magnetic body is at an intermediate position between the two magnetic sensors , and each of the output values is smoothly reduced corresponding to the position of the magnetic body. The electronic zoom operation mechanism according to claim 1, wherein the position and gain of the magnetic sensor are adjusted. The rotary member rotates the outer periphery on the barrel of the lens, electronic zoom operation mechanism according to claim 1 or 2. The optical instrument which has a lens provided with the electronic zoom operation mechanism of any one of Claims 1-3 . A projector comprising the electronic zoom operation mechanism according to any one of claims 1 to 3 .

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