KR100584981B1 - Apparatus which controlls the angle of rotation in scanning mirror - Google Patents

Abstract

The present invention relates to an apparatus for adjusting the rotation angle of a scanning mirror, and more particularly, a scanning mirror having an amplifying part at an output terminal of a digital / analog converter so as to adjust a gain value of the amplifying part by using a gain value register. It relates to a rotation angle adjusting device of.

In addition, the present invention is a scanning mirror that rotates left and right according to the input analog voltage value when the analog voltage value is input; A memory for storing rotation angle related data of the scanning mirror; A scanning mirror controller configured to read and output rotation angle related data from the memory; A digital / analog converter for converting the digital value output from the scanning mirror controller into an analog voltage value and outputting the analog voltage value; And an amplifying means for amplifying the analog voltage value of the digital / analog converter according to a predetermined gain value and outputting the amplified signal to the scanning mirror.

Spatial Light Modulator, Diffraction Type, Display, Rotation Angle

Description

Apparatus which controlls the angle of rotation in scanning mirror}             

Fig. 1 shows a typical configuration of an optical MEMS device applied to an optical switch and an optical modulation device by using light reflection or diffraction.

2 is a cross-sectional view of a recessed diffractive optical modulator using a piezoelectric material developed by Samsung Electro-Mechanics.

3 shows one embodiment of a display system using a spatial light modulator.

4A and 4B are diagrams illustrating a difference between a scanning method of a general display system and a scanning method of a display system using a spatial light modulator.

5A and 5B are diagrams for explaining a problem of an image reflected on a screen according to a conventional apparatus for adjusting a rotation angle of a scanning mirror.

6 is a block diagram of an apparatus for adjusting a rotation angle of a scanning mirror according to an embodiment of the present invention.

7A is a diagram illustrating an output voltage value of the digital / analog converter of FIG. 6, and FIG. 7B is a diagram illustrating an output voltage value of the amplifier of FIG. 6.

8 is an exemplary view illustrating an embodiment of the amplifier of FIG. 6.

<Explanation of symbols for the main parts of the drawings>

100: memory 110: scanning mirror control unit

120: digital-to-analog converter 130: amplifier

131: operational amplifier 132: variable resistor

133: resistor 140: gain value resistor

150: scanning mirror

The present invention relates to an apparatus for adjusting the rotation angle of a scanning mirror, and more particularly, a scanning mirror having an amplifying part at an output terminal of a digital / analog converter so as to adjust a gain value of the amplifying part by using a gain value register. It relates to a rotation angle adjusting device of.

In accordance with the development of microtechnology, attention has been paid to small devices incorporating micro electromechanical systems (MEMS) devices and MEMS devices. A MEMS device is a device formed as a microstructure on a substrate such as a silicon substrate or a glass substrate, and electrically and mechanically coupled to a driver for outputting a mechanical driving force, a semiconductor integrated circuit for controlling the driver, and the like. A basic feature of the MEMS device is that a drive body constructed as a mechanical structure is assembled to a part of the device, and the drive of the drive body is performed electrically by applying the coulomb force between the electrodes.

Fig. 1 shows a typical configuration of an optical MEMS element applied to an optical switch and an optical modulator by using light reflection or diffraction.

The optical MEMS element 11 shown in FIG. 1 includes a substrate 12, a substrate side electrode 13 formed on the substrate 12, and a beam 14 that spans the substrate side electrode 13 in a bridge shape. Achieve. The beam 14 and the board | substrate side electrode 13 are electrically insulated by the space | gap 10 between them. The beam 14 is placed on the bridge member 15 in parallel with the bridge member 15 facing the substrate side substrate 13 and the bridge member 15 standing on the substrate 12 by hanging the substrate side electrode 13 in a bridge shape. It consists of the drive side electrode 16 provided.

The beam 14 is formed in a so-called bridged manner with its ends supported. In this optical MEMS element 11, the beam 14 is displaced by the electrostatic attraction between the substrate side electrode 13 and the potential given to the substrate side electrode 13 and the driving side electrode 16. For example, as shown by the solid line and the broken line of FIG. 1, it displaces with respect to the board | substrate side electrode 3 in parallel state and concave state. In the optical MEMS element 11, light is irradiated onto the surface of the driving side electrode 16, which also serves as a light reflection film, and reflecting light in one direction is made using a different reflection direction of the light depending on the driving position of the beam 14. It can be applied as an optical switch that detects and has a switch function. The optical MEMS element 11 can be applied as an optical modulator for modulating light intensity. When using the reflection of light, the beam 14 is vibrated to modulate the light intensity with the amount of reflected light in one direction per unit time. This is generally called a reflective spatial light modulator. When using diffraction of light, a plurality of beams 14 are arranged in parallel with respect to a common substrate side electrode 13 to form an optical modulator, and for example, one beam 14 for the common substrate side electrode 13 is disposed. The height of the driving side electrode serving as the light reflection film is changed by the operation of the proximity and the separation of), and the intensity of the light reflected by the driving side electrode is modulated by the diffraction of the light. This is generally called a diffractive spatial light modulator.

2 is a cross-sectional view of a diffractive spatial light modulator (depressed type) using a piezoelectric material developed by Samsung Electro-Mechanics.

Referring to the drawings, the diffraction type spatial light modulator (depressed type) developed by Samsung Electro-Mechanics includes a silicon substrate 30 and a plurality of elements 22a to 22n. The silicon substrate 20 has depressions to provide air space to the elements 22a to 22n, and an insulating layer 21 is deposited on the upper surface, and ends of the elements 22a to 22n on both sides of the depressions. Is attached. Each element (herein, only the reference numeral 22a is described in detail, but the other 22b to 22n is the same) has a rod shape, and the lower surfaces of both ends are positioned so that the center portion is spaced apart from the depression of the silicon substrate 20. A portion located at both sides of the silicon substrate 20 beyond the depression and located at the depression of the silicon substrate 20 includes a lower support 23a movable up and down. In addition, the element 22a is stacked on the left end of the lower support 23a, and is laminated on the lower electrode layer 24a and the lower electrode layer 24a for providing a piezoelectric voltage, and contracts and A piezoelectric material layer 25a that expands to generate a vertical driving force and an upper electrode layer 26a that is stacked on the piezoelectric material layer 25a and provides a piezoelectric voltage to the piezoelectric material layer 25a are included. In addition, the element 22a is stacked on the right end of the lower support 23a, and is laminated on the lower electrode layer 24a 'and the lower electrode layer 24a' for providing a piezoelectric voltage. A piezoelectric material layer 25a 'that contracts and expands to generate a vertical driving force, and an upper electrode layer 26a' that is stacked on the piezoelectric material layer 25a 'and provides a piezoelectric voltage to the piezoelectric material layer 25a'. Doing.

The elements 22a to 22n form a multiple of λ / 4 when the wavelength of incident light is λ between adjacent elements 22a to 22n to diffract the incident light to form diffracted light. In addition, Korean Patent Application No. P2003-077389 describes the protruding type in addition to the depression type described above.

3 is a diagram illustrating an embodiment of a display system using a spatial light modulator.

The display system 31 according to the present embodiment is used, for example, as a projector for a large screen, particularly as a projector for digital images or as a computer image projection apparatus.

As shown in Fig. 3, the laser display 31 has an optical axis image for each of the laser light sources 32R, 32G, and 32B of each color of red (R), green (G), and blue (B) and for each laser light source. And color tone optical systems (lens group) 36R, 36G, 36B, and spatial light modulators 38R, 38G, 38B.

In addition, the display system 31 combines the red (R) laser light, the green (G) laser light, and the blue (B) laser light, respectively, whose light intensities are modulated by the spatial light modulators 38R, 38G, and 38B. A synthesis filter 40, a spatial filter 42, a diffuser 44, a mirror 46, a scanning mirror 48, a projection lens 50 and a screen 52 are provided. The color synthesis filter 40 is composed of, for example, a dichronic mirror.

In the display system 31 of the present embodiment, each of the RGB laser beams emitted from the laser light sources 32R, 32G, and 32B passes through each of the color tone optical systems 36R, 36G, and the like via the mirrors 34R, 34G, and 34B. 36B) and enters the spatial light modulators 38R, 38G, 38B. Each laser light is a color-coded image signal, and is input in synchronization with the spatial light modulators 38R, 38G, and 38B.

In addition, each laser light is spatially modulated by diffraction by the spatial light modulators 38R, 38G, 38B, and these three colors of diffracted light are synthesized by the color synthesis filter 40, and then the spatial filter 42 Only signal components are extracted by this.

This RGB image signal is then reduced in laser space by the diffuser 44, developed in space by the scanning mirror 48 in synchronization with the image signal via the mirror 46, and by the projection lens 50. Projected on the screen 52 as a full color image. Here, the scanning mirror 48 serves to reflect light like a normal mirror, and rotates to adjust the reflected angle upon reflection. At this time, the rotation angle of the scanning mirror 48 can be adjusted according to the magnitude of the input voltage.

On the other hand, control systems of such display systems include optical modulator drivers 60R, 60G, and 60B for controlling the spatial light modulators 38R, 38G, and 38B, and a scanning mirror controller 62 for controlling the scanning mirror 48. The optical modulator drivers 60R, 60G, and 60B receive the image signal information from the outside and control the spatial light modulators 38R, 38G, and 38B accordingly to generate the image signal by the diffracted light. In addition, the scanning mirror controller 62 controls the rotation angle of the scanning mirror 48 so that the image signal generated by the spatial light modulators 38R, 38G, 38B is scanned on the screen 52.

In general, in the case of a CRT CRT television, a horizontal scanning method is used as shown in FIG. 4A to implement an image on a screen. However, a display system using a spatial light modulator is scanned on a vertical line as shown in FIG. 4B. Use the method of continuous scanning while moving to. In the case of HD-quality television images, the screen resolution is 1920 * 1080, so when using a spatial light modulator, 1920 vertical lines must be continuously scanned horizontally. Therefore, the scanning mirror also needs 1920 operations to rotate from the left to the right of the screen, and the image reflected on the screen can be properly implemented only when the correct angle is rotated.

In particular, the rotation angle of the rotating scanning mirror is important in order to project an image of a suitable size on the screen. If this rotation angle is too large, the image reflected on the screen may be distorted or partly cut off, as shown in FIG. 5A. do. If the rotation angle is too small, as shown in FIG. 5B, the image reflected on the screen is too small to produce a blank screen and a black image.

Meanwhile, in the conventional rotation angle adjusting device of the scanning mirror, a digital / analog converter is placed between the scanning mirror and the scanning mirror controller, and the scanning mirror rotates depending on the output voltage of the digital / analog converter. However, the conventional technology is a method in which the scanning mirror control unit rotates the scanning mirror by storing data related to the rotation angle in advance in the memory and reading data stored in the memory and inputting the data into the digital / analog converter in synchronization with the spatial light modulator. According to the conventional technology, since the same data is input to all memories when manufacturing a product, and the individual and component characteristics of each product are not taken into consideration when manufacturing the product, that is, since the same input data is used, an error may occur. It happens. To solve this problem, it is necessary to understand the device characteristics used to modify the data stored in the memory, which is difficult to solve because it is almost impossible and the resolution of the digital / analog converter is limited.

Accordingly, an object of the present invention is to provide an apparatus for adjusting the rotation angle of a scanning mirror without changing the data stored in the memory and without being affected by the resolution of the digital / analog converter. .

The present invention for solving the above problems, the scanning mirror rotates left and right according to the input analog voltage value when the analog voltage value is input; A memory for storing rotation angle related data of the scanning mirror; A scanning mirror controller configured to read and output rotation angle related data from the memory; A digital / analog converter for converting the digital value output from the scanning mirror controller into an analog voltage value and outputting the analog voltage value; And amplifying means for amplifying the analog voltage value of the digital / analog converter according to a predetermined gain value and outputting the amplified signal to the scanning mirror.

Now, a rotation angle adjusting device of the scanning mirror according to an exemplary embodiment of the present invention will be described in detail with reference to the drawings of FIG. 6 and below.

6 is a block diagram of an apparatus for adjusting a rotation angle of a scanning mirror according to an exemplary embodiment of the present invention.

Referring to the drawings, the rotation angle adjustment apparatus of the scanning mirror according to an embodiment of the present invention, the memory 100, the scanning mirror control unit 110, the digital / analog converter 120, the amplifier 130, gain The value register 140 and the scanning mirror 150 are included.

The memory 100 may be an EEPROM or a flash memory, and the rotation angle data is stored, and the coordinate values of the starting point of the scanning mirror 150, the voltage values at the points, and the discrete coordinate values of the paths to pass through The voltage value at that point, the coordinate value of the end point, and the voltage value at that point are stored.

In addition, the memory 100 stores related data necessary for the reverse rotation so that the scanning mirror 150 rotates by the required rotation angle and then returns to the starting point, that is, to return to the starting point.

That is, the memory 100 stores the coordinate values of the end points of the scanning mirror 150, the voltage values at the points, the discrete coordinate values of the path required for the reverse rotation, and the voltage values at the points.

In addition, the memory 100 stores a corresponding value for adjusting the gain value of the amplifier 130.

The scanning mirror controller 110 reads the gain value of the amplifier 130 from the memory 100 and stores the gain value in the gain value register 140. When the user inputs a new gain value from the outside, the scanning mirror controller 110 stores the new gain value. Save to 100.

The scanning mirror controller 110 reads the coordinate value of the desired position and the voltage value according to the position from the memory 100, and generates and outputs a control signal for controlling the position of the scanning mirror 150.

At this time, the scanning mirror control unit 110 reads the rotation angle related data stored in the memory 100 in accordance with the synchronization of the spatial light modulator, and calculates a control signal (strictly, voltage value) from the read rotation angle related data. To the analog converter 120.

The digital / analog converter 120 converts the digital value input from the scanning mirror controller 110 into an analog value and provides the analog value to the amplifier 130. The reason why such a digital / analog converter 120 is required is that the signal flow at the front end of the digital / analog converter 120 is based on the digital signal, but the signal flow at the rear end of the digital / analog converter 120 is based on the analog. Because it is. That is, the rotational movement of the scanning mirror 150 proceeds analogously.

The amplifier 130 amplifies and outputs the analog value input by the digital / analog converter 120, and the ratio of the input voltage to the output voltage changes according to the gain value. The larger the gain value, the more the output voltage is compared with the input voltage. It becomes big.

Here, the gain value of the amplifier 130 may be variable, and if the gain value is changed, the magnitude of the output voltage is changed accordingly and the rotation angle of the scanning mirror 150 is changed. That is, when the gain value of the amplifier 130 is increased, the rotation angle of the scanning mirror 150 is increased, and the image of the screen is increased. When the gain value is decreased, the rotation angle of the scanning mirror 150 is decreased. The screen image becomes small.

 The gain value register 140 stores the gain value of the amplifier 130 so that the gain value of the amplifier 130 may be adjusted according to the stored gain value when the rotation angle adjusting device operates.

The gain register 140 is controlled by the scanning mirror controller 110. The user observes the image state of the screen and adjusts the gain value of the gain register 140 through the scanning mirror controller 110 according to the observation result. do. That is, the user observes the image state of the screen and inputs a larger gain value if the image is smaller than the screen size, and inputs a smaller gain value if the image is larger than the screen.

The scanning mirror 150 may be a galvanometer method as a device that can obtain the image information of the target surface by scanning the target (Target).

In general, the scanning mirror 150 of the galvanometer method is composed of a scan mirror that rotates a certain angle by the galvanometer and the galvanometer. Here, the galvanometer unit consists of a stator in which a drive coil is wound, a pair of permanent magnets attached to both sides of the stator, and a rotor which rotates inside the stator. The rotor is connected to the scan mirror so that the rotation of the rotor is connected to the rotational motion of the scan mirror.

Four air gaps are formed between the rotor and the stator, and these air gaps have a magnetic flux balanced by permanent magnets. When the controlled voltage is supplied to the drive coils wound on both sides of the stator, the magnetic flux increases in the pair of air gaps and the magnetic flux decreases in the other air gaps in the diagonal air gap. At this time, the rotor rotates in a direction coinciding with the air gap of the strong magnetic flux.

The rotor is connected to the scan mirror so that the rotational movement of the rotor is represented by the rotation of the scan mirror. By adjusting the direction and intensity of the unbalanced magnetic flux generated by the permanent magnet and the drive coil as described above, the angle of the scan mirror connected to the rotor is adjusted. At this time, the torsion spring is interposed to adjust the rotation angle of the rotor to a rotation angle proportional to the voltage flowing through the coil.

Now, the operation of the apparatus for adjusting the rotation angle of the scanning mirror according to the preferred embodiment of the present invention will be described in detail with reference to FIG. 6.

First, when the on-signal is input from the outside, the scanning mirror controller 110 reads the gain value of the amplifier in the memory 100 and stores it in the gain value register 140.

In addition, the scanning mirror controller 110 reads the coordinate value of the start point of the scanning mirror 150 in the memory 100, reads the voltage value accordingly, and outputs it to the digital / analog converter 120. Subsequently, the scanning mirror controller 110 reads the discrete coordinate values and corresponding voltage values located in the movement path of the scanning mirror 150, and outputs them to the digital / analog converter 120 to output the digital mirror to the digital / analog converter 120. Continue until you get the coordinates of the endpoint. As such, when the scanning mirror controller 110 reads and outputs all coordinate values of the forward rotational motion of the scanning mirror 150 and the voltage values thereof, the scanning mirror controller 110 continues to have a start point in the reverse rotation path and discrete coordinate values and end points on the path. The coordinate value of and the corresponding voltage value are read and output, and this operation-forward rotation and reverse rotation is repeated.

Next, the magnitude value of the output value of the digital-to-analog converter 120 is shown in FIG. 7A, but the output value increases and decreases at some point.

Herein, a section in which the output value becomes larger and larger is a section in which the tilt value becomes positive, and a rotation direction of the scanning mirror 150 becomes a positive direction, and a section in which the output value becomes smaller and smaller becomes a section in which the tilt value becomes negative. It is a section in which the rotation direction of 150 is reversed. In the case of the HDTV standard, when the reference frequency is 60 Hz, one framing data is output every 16.7 ms, and the output value becomes 16.7 ms in combination with the larger and smaller intervals.

Then, an output value as shown in FIG. 7A of the digital / analog converter 120 is input to the amplifier 130, and the amplifier 130 amplifies and outputs the input voltage value according to the set gain value.

At this time, the value according to the variable gain of the amplified voltage value output by the amplifier 130 is shown in Figure 7b. If the gain value is increased based on 0V, a larger positive value is negative for the positive value A smaller negative value is obtained for the value of, and as the gain decreases, a smaller positive value is obtained for the positive value and a smaller negative value for the negative value.

The scanning mirror 150 rotates according to the output value of the amplifying unit 130. When the output value of the amplifying unit 130 has a smaller starting point and a larger inclination, the scanning mirror 150 rotates by increasing the rotation angle. If the output value of 130 has a larger starting point and a smaller inclination, the rotation angle is reduced and the rotational motion is performed.

At this time, the user observes the state in which the image is displayed on the screen, and if the image is smaller than the screen, the user sets the increased gain value of the amplifier 130 so that the rotation angle becomes larger so that the image fills the screen. Then, if the user observes that the image is larger than the screen, the user sets the reduced gain value of the amplifier 130 to make the rotation angle smaller so that the image fits on the screen.

The gain value of the amplifying unit 130 is set by the user using the scanning mirror controller 110, and the scanning mirror controller 110 stores the gain value once set by the user in the memory 100. After that, the gain value stored in the memory 100 is loaded into the gain value register 140.

As such, when the user sets the appropriate gain value while checking the screen and the image reflected on the screen, the set data is stored in the memory 100 so that the same size image can be always seen without distortion or other obstacles.

FIG. 8 is a circuit diagram illustrating an exemplary embodiment of the amplifier of FIG. 6 and includes an operational amplifier 131, a variable resistor Rv 132, and a resistor R133.

The output voltage Aout of the digital / analog converter is connected to the non-inverting terminal of the operational amplifier 131, and the reference voltage Vr is connected to the inverting terminal.

A variable resistor Rv is connected between the inverting terminal of the operational amplifier 131 and the output terminal, and the resistance value of the variable resistor Rv is adjusted by the output value of the gain register.

Now, referring to FIG. 8, the operation of the amplifier used in the present invention of FIG. 6 will be described.

In general, the voltage difference between the inverting terminal and the non-inverting terminal of the operational amplifier 131 has a value of 0, and the voltage of the inverting terminal is equal to the output voltage Aout of the digital / analog converter of the non-inverting terminal.

Therefore, when the current flowing through the inverting terminal is I, the voltage of the inverting terminal is Aout as described above, and I = (Aout-Vr) / R because the voltage on the input side of the resistor R is Vref.

On the other hand, since the current flowing through the inverting terminal of the operational amplifier 131 is zero, the current I flows through the variable resistor Rv to the output terminal. Therefore, the output voltage Vout of the output terminal becomes as follows (Equation 1).

Vout = ((R + Rv) / R) Aout- (Rv / R) Vr

Therefore, it can be seen that the output voltage Vout is proportional to the resistance value Rv of the variable resistor when the input voltage is Aout.

Therefore, the output value can be adjusted by appropriately adjusting the resistance value of the variable resistor.

According to the present invention as described above, it is possible to adjust the rotation angle of the scanning mirror only by adjusting the register data to solve the conventional problem, the rotation angle error due to the error of the digital / analog converter or the rotation by the difference of the scanning mirror itself It is effective to solve each error.

In addition, according to the present invention, if the user checks the screen and the image reflected on the screen and sets the appropriate register data, the set data is stored in the memory so that the image of the same size can always be seen without distortion or other obstacles. .

Herein, while the present invention has been described with reference to the preferred embodiments, those skilled in the art will variously modify the present invention without departing from the spirit and scope of the invention as set forth in the claims below. And can be changed.

Claims (4)

A scanning mirror rotating left and right according to the input analog voltage value when an analog voltage value is input; A memory for storing rotation angle related data of the scanning mirror; A scanning mirror controller configured to read and output rotation angle related data from the memory; A digital / analog converter for converting the digital value output from the scanning mirror controller into an analog voltage value and outputting the analog voltage value; And And amplifying means for amplifying the analog voltage value of the digital / analog converter according to a predetermined gain value and outputting the amplified signal to the scanning mirror. The method of claim 1, The amplification means, An amplifier for amplifying and outputting the digital / analog voltage value according to a predetermined gain value; And And a gain value adjusting unit for adjusting a gain value of the amplifying unit. The method of claim 2, The amplification unit, A resistor having one end connected to a reference voltage; An operational amplifier having the digital / analog voltage value connected to a non-inverting terminal and the resistor connected to an inverting terminal; And And a variable resistor connected between the inverting terminal and the output terminal of the operational amplifier and varying a resistance value under the control of the gain control unit. The method of claim 2, The gain value adjusting unit, Characterized in that the gain value register for storing the gain value of the amplifier, When the gain value of the amplifying unit is input from the outside, the scanning mirror controller stores the gain value input to the memory, and loads the gain value stored in the memory into the gain value register. Regulator.

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