KR101426552B1 - Iris apparatus - Google Patents

Abstract

The iris apparatus of the present invention includes: a power source control unit for controlling and outputting an input power source; An iris motor operated by an output power from the power source control unit; And a mechanism for adjusting the size of the iris through hole according to the rotation angle of the iris motor, wherein the output power input to the iris motor is a bi-directional current having a plus direction and a minus direction.

According to the present invention, the control characteristic of the opening and closing amount of the iris is improved without being affected by the magnetic hysteresis of the magnetic body, so that it is possible to quickly cope with the external light quantity to obtain a clearer image and to improve the adverse effect by hysteresis It is possible to take a picture even if the power of the camera is broken, because the manufacturing cost is reduced and the iris is opened by about half in the absence of the power source. The reliability is improved.

Iris, motor

Description

An iris device {Iris apparatus}

1 is a front view of an iris device according to the present embodiment.

2 is a rear view of the iris device according to the present embodiment.

3 is a sectional view of the motor according to the present embodiment.

4 is a graph showing the relationship between the current applied to the motor and the size of the transmission hole.

5 is a graph showing a correlation between the voltage of the motor of the iris device according to the present embodiment and the magnitude of the transmission hole and the degree of opening of the iris.

6 is a block diagram of an iris device according to the present embodiment.

FIGS. 7 and 8 are graphs showing experimental results of the iris apparatus according to the present embodiment, wherein FIG. 7 shows results of experiments with sinusoidal waves, and FIG. 8 shows experiments with triangular waves.

9 is a graph showing the results of experiments in which the through holes of the iris are completely closed when there is no external power source.

Description of the Related Art

10: iris device 13, 14: iris wing

20: motor 113: transmission hole

121, 123: connection axis

The present invention relates to an iris device.

The photographing apparatus can be widely understood as an apparatus for photographing an image. Among them, a photographing apparatus capable of digital image processing is a device for photographing a subject and recording the generated image signal on a recording medium through a predetermined signal processing. In the digital photographing apparatus, the photographing of the subject is performed by the photographing device provided in the photographing apparatus. Examples of the photographing apparatus include a camera, a closed circuit television (CCTV), and the like.

In order for the imaging apparatus to capture a subject more clearly, the amount of light incident on the imaging element must be maintained at an appropriate amount. This is a similar concept to the iris when viewed from the naked eye. To this end, the imaging device is provided with an iris device for adjusting the amount of light incident on the imaging device.

That is, the photographing apparatus provides a function of automatically adjusting the opening / closing amount of the iris device to optimize the amount of light incident on the imaging device. When the subject is dark, the iris is opened to increase the amount of light incident on the imaging device, When the subject is bright, the iris is closed to reduce the amount of light incident on the imaging element. The iris is also called an iris.

The iris generally controls the amount of light incident through the aperture in such a manner that the size of the aperture formed by the combination of a plurality of plates is adjusted. In order to operate the plate, a motor composed of a combination of a permanent magnet and an electromagnet is generally provided. The permanent magnets rotate by a certain angle toward an angle that balances the magnitude of the force between the magnetic force formed by the solenoid and the magnetic force formed by the ferromagnetic material forming the case of the motor.

The term motor here refers to a concept that is different from a motor that produces a continuous rotational force in a general sense, a device that moves finely within a short range of angles. However, a device in which rotation is caused by application of a current is referred to as a motor within a range called a motor.

It is important that the iris device reacts quickly according to the amount of external light to adjust the opening of the plate. However, there is a problem that the control characteristic of the motor is not good due to the hysteresis of the ferromagnetic material used in the motor.

In other words, since the motor can not be instantaneously driven by the input current due to the magnetic hysteresis of the magnetic body, if the outside becomes suddenly bright, the screen becomes clogged and hysteresis There is a problem that the speed of response to the external light amount is deteriorated if the external current is forcibly limited.

The present invention proposes an iris device in which the control characteristic with respect to the opening and closing amount of the iris is improved despite the magnetic hysteresis of the magnetic body. In particular, the iris device is improved in response to the input current with respect to the reaction rate of the iris opening / closing amount and the correspondence of the specific iris opening / closing amount with respect to the specific input current.

It also proposes an iris device that solves the problem of magnetic hysteresis simply without a circuit improvement and a complicated current control.

The iris apparatus of the present invention includes: an iris blade for adjusting a size of a transmission hole through which external light is incident; A connection shaft for adjusting the position of the iris blade; And a motor connected to the connection shaft so as to indicate a state in which the transmission hole is opened when there is no external power source.

An iris apparatus according to the present invention includes: a power source control unit for controlling and outputting an input power source; An iris motor operated by an output power from the power source control unit; And a mechanism for adjusting the size of the iris through hole according to the rotation angle of the iris motor, wherein the output power input to the iris motor is a bi-directional current having a plus direction and a minus direction.

According to the present invention, since the iris device is driven irrespective of the characteristic of the hysteresis, it is possible to improve the image quality of the captured image quickly corresponding to the amount of external light, to reduce the manufacturing cost because a complicated circuit structure is not required, There is an advantage that the reliability of the iris is improved at a low temperature.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. It should be understood, however, that the scope of the present invention is not limited to the preferred embodiments shown and that other embodiments may be easily suggested by adding, changing, deleting, and adding elements, I would say.

FIG. 1 is a front view of an iris apparatus according to the present embodiment, and FIG. 2 is a rear view of an iris apparatus according to the present embodiment.

1 and 2, the iris apparatus 10 according to the present embodiment includes a plate 11 having a transmission hole 113 of a predetermined size formed at the center thereof, And a first iris blade 13 and a second iris blade 14 slidable in the left and right direction by the motor 20.

In detail, the first connection shaft 121 and the second connection shaft 123 are rotatably connected to the motor 20. Therefore, the first connection shaft 121 and the second connection shaft 123 rotate clockwise or counterclockwise by the forward / reverse rotation of the motor 20.

Protrusions 122 and 124 protruding from the back surface of the plate 11 are formed at the ends of the first and second connection shafts 121 and 123, respectively. Guide holes 111 and 112 are formed in the plate 11 to accommodate the protrusions 122 and 124 and rotate in a predetermined angle range in a forward or reverse direction.

Each of the first and second iris blades 13 and 14 has protruding holes 135 and 145 for receiving the protruding portion 124, respectively. Accordingly, when the motor 12 rotates in one direction, the first iris blade 13 and the second iris blade 14 slide in opposite directions to open or close the transmission hole 113.

A plurality of guide protrusions 114 are formed on the rear surface of the plate 11. Guide holes 114 are formed in the upper and lower ends of the first and second iris blades 13 and 14, (134) and (144) are formed. Therefore, when the motor 12 rotates, the guide pins 133 and 144 guide the movement of the iris blades 13 and 14 in the left and right directions. The guide holes 133 and 144 and the guide protrusion 114 allow the iris blades 13 and 14 to move freely without being detached from the plate 11.

The first and second iris blades 13 and 14 are laminated on the back surface of the plate 11. Accordingly, when the first iris blade 13 and the second iris blade 14 slide in opposite directions, the surface of the first iris blade 13 and the second iris blade 14 contact each other. As the iris blades 13 and 14 move, Or shielded. When the size of the transmission hole 113 is increased, the amount of incident light is increased to enable imaging even in a dark place. When the size of the transmission hole 113 is reduced, the amount of incident light is reduced. Conversely, the size of the transmission hole 113 should be increased to increase the amount of incident light in a dark place, and the size of the transmission hole 113 should be reduced so that the amount of incident light is reduced in a bright place.

Since the size of the transmission hole 113 corresponds to the rotation angle of the motor 20, the structure of the motor, particularly the configuration of the motor in which the influence of the hysteresis characteristic of the present embodiment is reduced will be described below. Will be described in detail.

3 is a sectional view of the motor according to the present embodiment.

Referring to Fig. 3, the motor 20 of the present embodiment has a case 21 in which an opening 24 is provided at a certain point in a circular form, and a permanent magnet 22 accommodated in the case 21 do. A solenoid (not shown) is provided at a position adjacent to the permanent magnet 22 to apply a magnetic field line 23 of the solenoid to the permanent magnet 22.

Here, the case 21 is a ferromagnetic body, and the position of the permanent magnet 22 is indicated by the opening 24 when there is no input current. The permanent magnet 22 serves as a driving shaft of the motor 20 and is rotated by a position where the magnetic force lines formed by the solenoid and the magnetic force lines formed by the case 21 are balanced. The solenoid is only required to apply the magnetic force lines generated from the solenoid to the permanent magnet 22, and the specific position may be a position where the magnetic force lines are applied in the directions shown in the figure.

The N pole of the permanent magnet 22 is aligned with the opening 24 in a state where the power is not applied to the motor 20. At this time, the through hole 113 is opened by about 50% (X1). In other words, in a state in which the input current to the motor 20 is zero, the iris device is opened by 50% and is arranged in a state in which the external light source is input. In this state, when the current is applied to the motor in the + direction and the maximum value is reached, the iris device is opened to 100%, the external light source is inputted to the maximum (X2), and when the current is inputted to the motor in the negative direction, And the external light source can not be incident (X3).

1 and 2, the maximum current is input to the motor in the -direction, and the connection shafts 121 and 123 are rotated in the clockwise direction with reference to Fig. 1, (113) is opened to the maximum. Of course, when the maximum current in the + direction is inputted to the motor, the connection shafts 121 and 123 are fully rotated counterclockwise with reference to FIG. 1, so that the transmission hole 113 is completely closed. If no current is input to the motor, the connection shafts 121 and 123 stand in a vertical direction, and about half of the external light amount is input.

Since the absolute value of the current input to the motor 20 is reduced by half, the hysteresis due to the residual magnetic flux is reduced and the malfunction of the motor due to the hysteresis is eliminated.

On the other hand, when the iris device of the present embodiment is used for a long time in an outdoor environment, such as a security camera, a greater advantage can be expected. For example, even in the case where water does not condense on the wings of the iris due to low temperature conditions such as a winter night, a certain amount of light may be incident on the iris. This can be clearly understood in comparison with the state in which the iris device is completely closed when there is no input power in the conventional case. In addition, since the condensed water has a small area of condensation, the frictional force between the iris blades is small, so that the condensed water quickly melts, and when the iris device is once operated, the operation is normally started more quickly.

This advantage is clearly understood in comparison with the conventional example in which a 0% size through hole is provided when no external power source is applied. In the case of a 0% size through hole, light can not be incident, It can be easily understood that it can not be achieved. It is also easy to understand that the overlapping portion of the iris wings is large, so that the time required for the water to evaporate due to the internal heat of the camera is long and the time required for the normal operation is long.

Hereinafter, the correlation between the hysteresis and the motor will be described in detail theoretically.

 4 is a graph showing the relationship between the current applied to the motor and the size of the transmission hole. However, FIG. 4 shows that the through hole is completely closed when no current is applied, and it is a result of a hypothetical experiment.

Referring to FIG. 4, an open curve 41 indicating a state in which the through hole 113 is gradually increased as the current is increased, and an open curve 41 indicating a state in which the current is decreased to reduce the size of the through hole 113 A second closing curve 42 and a first closing curve 43 for reducing the magnitude of the transmission hole 113 by reducing the current without reaching the maximum are shown.

It can be seen that the curves do not show a linear relationship, which is due to the magnetic history of the magnetic body. More specifically, in the opening curve 41, it is seen that the through hole 113 becomes larger gradually as the electric current is increased by the magnetic hysteresis. Even if the current gradually decreases after the current reaches the maximum in the second closing curve 42, the size of the transmission hole 113 is not reduced, the current is reduced to a certain degree, and then the size of the transmission hole 113 is suddenly decreased Can be observed. If the current is gradually decreased in the state where the current does not reach the maximum in the first closing curve 43, it can be observed that the size of the transmission hole 113 gradually decreases from the beginning even if it is not the same as the opening curve 41 have.

Such a graph is caused by the magnetic hysteresis generated in the ferromagnetic material which is the material of the case 21. [ In the magnetic hysteresis phenomenon, if the ferromagnetic material becomes the magnetic saturation state and has the maximum degree of magnetization, the magnetization is reduced relatively slowly even if the magnetic field is reduced, and the residual magnetization having the magnetization remains even if the magnetic field is completely eliminated. At this time, when the magnetic field is reversed to some extent, the residual magnetization disappears. At this time, the intensity of the magnetic field to be applied in the reverse direction is referred to as the coercive force of the magnetic body. A magnetic hysteresis occurs due to the residual magnetic flux density.

Here, the coercive force becomes larger as the magnitude of the magnetization increases, as seen from the open curve 41, near the maximum current value. That is, when the magnetic body becomes magnetically saturated, the residual magnetic flux density becomes large, and the magnetic field must be magnified in the reverse direction. By physically analyzing this state, it is necessary to apply a larger reverse current to close the iris as the current approaches the maximum current value of the magnetic body - the current value which obtains the maximum magnetization obtained by the specific magnetic body - to open the iris It means something.

In view of this, in this embodiment, the state before the magnetic body becomes magnetic saturation is used to allow the iris device to open or close the through hole 100% before being magnetically saturated.

5 is a graph showing a correlation between the voltage of the motor of the iris device according to the present embodiment and the magnitude of the transmission hole and the degree of opening of the iris.

Referring to FIG. 5, the transmission hole is half in a state without a voltage, and the size of a transmission hole increases along a first opening curve 31 when the + voltage is gradually increased. If the + voltage is reduced after the maximum transmission hole has been reached, the size of the transmission hole gradually decreases along the first closing curve 34. Then, when the voltage is gradually increased, the size of the transmission hole decreases along the second opening curve 32. The transmission hole gradually increases in size along the second closing curve 33 when the - voltage is decreased after the transmission hole reaches the minimum.

In this case, since the iris device can be operated within a relatively small range of magnetic hysteresis - a range in which the influence of the magnetic hysteresis is insignificant, which is not sufficiently attained in the magnetic saturation state - the motor 20 can be operated substantially without hysteresis An effect that can be operated can be obtained. This can be understood sufficiently in comparison with the graph of the correlation between the voltage of the motor of the iris device and the magnitude of the transmission hole - the degree of opening of the iris - in the region reaching the magnetic saturation state indicated by the dotted line.

As described, the size of the iris through hole is gradually changed according to the voltage, so that the disadvantage that the image suddenly brightens or darkens can be improved.

6 is a block diagram of an iris device according to the present embodiment.

Referring to FIG. 6, the iris apparatus of the present embodiment includes a power supply control unit 100 for adjusting an electric current with external power applied thereto, a motor 200 for generating a driving force by being supplied with power from the power supply control unit 100, And a mechanism 300 for controlling the size of the transmission hole 113 by transmitting the driving force of the motor 200. In particular, the power supply control unit 100 generates at least positive voltage and negative voltage to apply the voltage to the motor 200. When the power is not applied to the motor 200, the size of the transmission hole 113 of the mechanical unit 300 is not zero.

Preferably, in order to minimize the influence of hysteresis and maximize the convenience of current control, the motor 200 is configured in such a state that the mechanism unit 300 is opened by about half desirable. 1 and 2, adjusting the arrangement of the motor 20 and the connecting shafts 112 and 123, corresponding to the first and second iris blades 13 and 14, . ≪ / RTI >

FIGS. 7 and 8 are graphs showing experimental results of the iris apparatus according to the present embodiment, wherein FIG. 7 shows results of experiments with sinusoidal waves, and FIG. 8 shows experiments with triangular waves.

Referring to FIGS. 7 and 8, it can be seen that the sizes 54 and 52 of the iris through holes correspond substantially to the input voltages 53 and 51.

9 corresponds to a result of an experiment in which the through hole of the iris is completely closed when there is no external power source.

Referring to FIG. 9, the size 56 of the iris through hole corresponding to the input voltage 55 can be seen. In detail, even if the input voltage gradually increases in the region A, the size of the transmission hole does not increase to a certain voltage at all, and the size of the transmission hole suddenly increases. In the region B, even if the input voltage is gradually decreased, the size of the transmission hole is maintained almost unchanged. In the C region, the input voltage slightly changes, but the size of the transmission hole suddenly decreases. In this case, it becomes difficult to control the iris, and various problems arise.

On the other hand, in order to solve the problem that the size of the transmission hole drastically changes in comparison with the voltage shown in FIG. 9, it is necessary to provide a differential circuit or an integrating circuit. According to the present invention, such a separate circuit is not required There are advantages. This, of course, reduces manufacturing costs.

Observing the state of Fig. 9 in comparison with Figs. 7 and 8, the effect of this embodiment is clearly understood.

In the embodiment of the present invention, when the current is not input, the transmission hole is opened by 50%, when the current in the + direction is inputted, 100% is opened. When the current is inputted in the -direction, As shown in Fig. However, it is also contemplated that it is possible to regulate 30% opening in the + direction and 70% opening in the -direction, not limited to this, which is an idle open state of the iris device - If there is -, it will be different depending on what is appropriate. However, it is more convenient to set it to 50% for convenience of current control unless otherwise noted.

According to the present invention, the control characteristic of the iris opening / closing amount is improved without being affected by the magnetic hysteresis of the magnetic body, so that it is possible to quickly cope with the external light quantity, thereby obtaining a clearer image.

In addition, since there is no need for a complicated current control device for improving the adverse effect caused by hysteresis, the manufacturing cost is reduced.

In addition, since the iris is opened by about half in a state in which no power source is present, there is an advantage that the camera can be taken even if the power source of the camera fails, and the reliability of the low temperature use condition is improved.

In addition, when the size of the transmission hole of the iris device occupying a large number of use conditions and the state of no input of the external power source are matched, it is expected that electric power required for the operation of the iris can be reduced.

Claims (6)

A power control unit for controlling and outputting an input power; An iris blade for adjusting a size of a transmission hole through which external light is incident; A connection shaft for adjusting the position of the iris blade; And A motor connected to the connection shaft is operated so as to perform an operation of moving the connection shaft by operating with an output power from the power source control unit and indicating a state in which the transmission hole is opened when there is no external power source And, The motor includes: A case formed in a circular shape and provided with an opening at one point, A permanent magnet accommodated in the case, And a solenoid provided at an adjacent position of the permanent magnet, A magnetic force line of the solenoid is applied to the permanent magnet, The N pole of the permanent magnet aligns with the opening in a state where power is not applied to the motor, the through hole is opened by 50% When a current is inputted to the motor in the direction of + or - and the absolute value thereof reaches a maximum value, the transmission hole is opened 100% A current is inputted to the motor in the other direction of + or -, and when the absolute value reaches the maximum value, the through hole is closed. delete The method according to claim 1, Wherein the permanent magnet is indicated by a rotational angle by a combination of a force between a magnetic force of the solenoid and a magnetic force of the case of the motor. delete delete The method according to claim 1, Wherein the maximum value of the current in the + direction and the direction in the operating range of the iris motor is the same as the absolute value of the current in the + direction and the - direction.

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