KR20110016626A - Apparatus and method for driving light scanner - Google Patents

Abstract

PURPOSE: An apparatus and a method for driving a light scanner are provided to synchronize a horizontal synchronization signal to a vertical synchronization signal of a fixed input image by changing a return section of the horizontal synchronization signal after generating a horizontal blank signal through the sensing operation of the horizontal synchronization signal of the optical scanner. CONSTITUTION: A horizontal blank signal generator(70) generates a horizontal blank signal from a processed sensing signal of a sensing signal processing unit(50). According to the horizontal blank signal, a synchronization signal adjustment unit(90) changes a return section of a horizontal synchronization signal. The synchronization signal adjustment unit synchronizes the horizontal synchronization signal to the vertical synchronization signal of the fixed input image. According to the adjusted horizontal and vertical synchronization signals, a driving signal generator(110) outputs the driving signal to an optical scanner(10).

Description

Apparatus and method for driving light scanner}

TECHNICAL FIELD The present invention relates to an optical scanner driver, and more particularly, to an optical scanner driver and a method of a projection display that can improve system stabilization and synchronization of video and audio.

In general, along with the rapid advancement into the multimedia society, large-sized and high-definition display screens are required, and in recent years, in addition to high resolution, the implementation of natural natural colors is important.

In order to achieve perfect natural colors, it is necessary to use a light source with high color purity, such as a laser. One of the devices for implementing an image using a laser is a laser projection display device using an optical scanner.

Such a laser projection display apparatus implements an image by scanning light generated from a laser light source onto a screen using an optical scanner.

In the case of the optical scanner, the driving speed should be high in order to implement a high resolution image.

That is, the high driving speed of the optical scanner means that the driving angle of the optical scanner should be large.

In the optical scanner, when the driving signal is a specific frequency, the driving angle tends to be large. The specific frequency of the driving signal that increases the driving angle of the optical scanner is called a resonance frequency.

Therefore, when the driving signal corresponds to the resonant frequency, the optical scanner has the largest driving angle and enables high speed driving.

However, since the optical scanners have different resonant frequencies due to manufacturing variations in the process, it is difficult to generate driving signals corresponding to the resonant frequencies in consideration of these.

In addition to such manufacturing variations in the process, the resonant frequency may vary depending on the intensity of light incident on the optical scanner.

That is, since the intensity of light incident on the optical scanner is not constant, the temperature of the optical scanner varies with time, and thus the resonant frequency of the optical scanner changes with time.

Therefore, the optical scanner does not drive corresponding to the vertical and horizontal driving signals input due to the variable resonant frequency, and there is a problem that a driving error occurs.

The driving error of the optical scanner may cause problems such that the left / right part of the displayed image is changed, the upper / lower part of the image is changed, or the size of the overall image is very small.

The present invention stabilizes the driving system of the optical scanner by using the vertical synchronizing signal of the input image signal as a fixed vertical synchronizing signal of the optical scanner and synchronizing the horizontal synchronizing signal to the fixed vertical synchronizing signal to drive the optical scanner. It is an object of the present invention to provide an apparatus and method for driving an optical scanner that can improve the synchronization of video and audio.

In accordance with another aspect of the present invention, an optical scanner driving apparatus includes an optical scanner driven by a drive signal, a sensing unit configured to sense driving of an optical scanner, a sensing signal processor configured to process a sensing signal sensed by the sensing unit, and a signal processed A horizontal blank signal generator for generating a horizontal blank signal indicating an active period of the horizontal sync signal from the sensing signal, and a horizontal blank signal for varying the return interval of the horizontal sync signal according to the horizontal blank signal, thereby horizontally syncing the vertical sync signal of the fixed input image And a driving signal generating unit for generating a driving signal and outputting the driving signal to the optical scanner according to the adjusted horizontal and vertical synchronizing signals.

Here, the sensing signal processor may include a noise removing unit for removing noise of the sensing signal sensed from the sensing unit, and a clock signal converter converting the sensing signal from which the noise is removed into a clock signal.

The synchronization signal adjusting unit may further include a memory for storing an input video signal, a synchronization signal generation unit for generating horizontal and vertical synchronization signals from the stored image signal, and a vertical synchronization signal for fixing the synchronization signal generator, and the horizontal blank signal. According to the horizontal blank signal input from the generation unit, it may be configured to include an adjusting unit for synchronizing the horizontal synchronization signal to a fixed vertical synchronization signal by varying the return section of the horizontal synchronization signal.

Here, the adjusting unit includes a synchronization unit for synchronizing the active period of the horizontal synchronization signal to the active period of the vertical synchronization signal, a counter unit for counting the frequency of the active period of the synchronized horizontal synchronization signal, and counted according to the horizontal blank signal. It may be configured to include a frequency variable for varying the frequency of the return section of the horizontal synchronization signal according to the frequency.

The frequency variable unit may further include an operation unit that calculates a difference value between the total frequency of the horizontal synchronization signal for one frame of the input video and the frequency of the active period of the counted horizontal synchronization signal, and the return interval of the horizontal synchronization signal according to the calculated difference value. It may be configured to include a frequency increase and decrease to increase or decrease the frequency of.

On the other hand, the driving method of the optical scanner according to the present invention, the step of applying a drive signal to the optical scanner, the step of sensing the drive of the optical scanner, the signal processing of the sensed sensing signal, the signal-processed sensing signal Generating a horizontal blank signal indicating an active period of the horizontal synchronization signal from the second signal; synchronizing the horizontal synchronization signal to a vertical synchronization signal of the fixed input image by varying a return period of the horizontal synchronization signal according to the horizontal blank signal; In response to the adjusted horizontal and vertical synchronization signals, the driving signal may be generated and output to the optical scanner.

Other objects, features and advantages of the invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

The optical scanner driving apparatus and method according to the present invention has the following effects.

The present invention senses the horizontal synchronization signal of the optical scanner, generates a horizontal blank signal indicating the active period of the horizontal synchronization signal, and according to the horizontal blank signal, by varying the return interval of the horizontal synchronization signal, the vertical synchronization of the fixed input image By synchronizing the horizontal synchronizing signal to the signal, it is possible to stabilize the drive system of the optical scanner and improve the synchronization of video and audio.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a driving device of an optical scanner according to the present invention.

As shown in FIG. 1, the present invention provides an optical scanner 10, a sensing unit 30, a sensing signal processing unit 50, a horizontal blank signal generating unit 70, a synchronization signal adjusting unit 90, and a driving signal generating unit. 110 can be configured to include.

Here, the optical scanner 10 is a MEMS (micro-electro-mechenical system) scanner, and resonantly drives by a drive signal shifted by 90 degrees.

In addition, the sensing unit 30 may sense driving of the optical scanner, and the sensing signal processor 50 may perform a signal processing of the sensing signal sensed by the sensing unit 30.

FIG. 2 is a diagram illustrating the sensing signal processor of FIG. 1. As illustrated in FIG. 2, the sensing signal processor 50 may include a noise remover 52 and a clock signal converter 54.

Here, the noise removing unit 52 serves to remove noise of the sensing signal sensed from the sensing unit 30, and the clock signal converter 54 crosses the sensing signal from which the noise is removed to zero crossing. To convert to a clock signal.

In addition, although not shown, the noise removing unit 52 may be configured to include a differential amplifier and an offset adjusting unit. The differential amplifier unit may differentially amplify an input sensing signal to remove noise, and the offset adjustment unit may differentially amplify the signal. It serves to adjust the offset of.

Next, the horizontal blank signal generator 70 generates a horizontal blank signal indicating an active section of the horizontal sync signal from the signal processed sensing signal.

Here, the horizontal blank signal may include information related to a timing and a frequency at which the optical scanner scans image data on the screen.

The synchronization signal adjusting unit 90 may adjust the horizontal synchronization signal to be synchronized with the vertical synchronization signal of the fixed input image by varying the return section of the horizontal synchronization signal according to the horizontal blank signal.

3 is a diagram illustrating a sync signal adjuster of FIG. 1, and may include a memory 92, a sync signal generator 95, and an adjuster 97, as shown in FIG. 3.

Here, the memory 92 stores an input video signal, and the sync signal generator 95 generates horizontal and vertical sync signals from the stored video signals.

Subsequently, the adjusting unit 97 fixes the vertical synchronizing signal of the synchronizing signal generating unit 95, and varies the return period of the horizontal synchronizing signal according to the horizontal blank signal input from the horizontal blank signal generating unit 70. It synchronizes the horizontal synchronization signal with the vertical synchronization signal.

FIG. 4 is a view showing the adjustment unit of FIG. 3, and as shown in FIG. 4, the adjustment unit 97 may include a synchronizer 100, a counter unit 102, and a frequency variable unit 104. .

First, the synchronization unit 100 synchronizes the active period of the horizontal synchronization signal to the active period of the vertical synchronization signal according to the horizontal blank signal.

Subsequently, the counter unit 102 counts the frequency of the active period of the synchronized horizontal synchronization signal, and the frequency variable unit 104 varies the frequency of the return period of the horizontal synchronization signal according to the counted frequency.

Here, the active period of the horizontal synchronization signal means the time when the vertical synchronization signal for one frame of the input image falls from high to low, and the return period of the horizontal synchronization signal is set to one frame of the input image. It means the time when the vertical synchronization signal rises from low to high.

In addition, although not shown, the frequency variable unit 104 may include a calculation unit and a frequency increase and decrease unit.

Here, the calculating unit calculates a difference value between the total frequency of the horizontal synchronizing signal for one frame of the input image and the frequency of the active interval of the counted horizontal synchronizing signal, and the frequency increasing / decreasing unit according to the calculated difference value. It may serve to increase or decrease the frequency of the return interval of.

In this case, the frequency increase and decrease unit may increase or decrease the frequency so that the amplitude of the frequency is irregular, and when the frequency increases or decreases, it is preferable to turn off the driving of the laser light source.

The reason is because the amplitude of the frequency is irregular, so as to suppress the occurrence of unnecessary noise on the screen.

Next, the driving signal generator 110 may generate a driving signal and output the driving signal to the optical scanner according to the adjusted horizontal and vertical synchronizing signals.

Although not shown, the driving signal generator 110 may include a memory unit, a digital-analog converter, a filter unit, and a frequency adjuster.

Here, the memory unit is a look up table, and includes a first memory unit storing a horizontal synchronizing signal for driving the optical scanner 10 and a second memory unit storing a vertical synchronizing signal for driving the optical scanner 10. It may be configured as a memory unit.

The digital-analog converter converts the horizontal synchronizing signal stored in the first memory into an analog signal and the second digital-analog converts the vertical synchronizing signal stored in the second memory into an analog signal. It may be composed of a conversion unit.

Next, the filter unit is a low pass filter, which is composed of first and second filter units, and generates a driving signal by removing high frequency components of the analog signal.

Subsequently, the frequency adjusting unit may adjust the frequency amplification of the synchronization signal stored in the memory unit according to the control signal.

Figure 5a is a view showing the synchronization of the horizontal and vertical frequency of the conventional optical scanner, Figure 5b is a view showing the synchronization of the horizontal and vertical frequency of the optical scanner according to the present invention.

In the general optical scanner driving method, as shown in FIG. 5A, when the horizontal and vertical synchronizing signals of the optical scanner are sensed, the horizontal synchronizing signal of the optical scanner is not constant according to the variable horizontal resonant frequency.

Therefore, when synchronizing the vertical and horizontal synchronizing signals, since the frequency of the horizontal synchronizing signal is not constant, the vertical synchronizing signal must be varied to be synchronized with the horizontal synchronizing signal, which is not constant.

For example, if the horizontal sync signal is variable and the frequency of the active section of the horizontal sync signal is greater than before, the active section of the vertical sync signal must also be increased to be synchronized with it.

 As described above, according to the variable horizontal synchronizing signal, the vertical synchronizing signal is changed, so that a loss may occur in a frame of an image, or two images may exist in one frame.

That is, if the frequency of the vertical synchronization signal is not constant, a problem may occur that the video and the audio are not synchronized with each other.

Therefore, according to the present invention, as shown in Fig. 5B, the vertical synchronization signal is always fixed constantly, and the frequency of the active period of the variable horizontal synchronization signal is synchronized with the active period of the vertical synchronization signal, and then the horizontal synchronization signal is returned. By varying the frequency of the section, the overall frequency can be synchronized.

For example, when the vertical synchronizing signal is fixed at about 60 Hz and the horizontal synchronizing signal is increased from about 18 KHz to 19 KHz, the frequency of the active period of the horizontal synchronizing signal is synchronized to the active period of the fixed vertical synchronizing signal, and the horizontal synchronizing signal is The overall frequency of can vary the horizontal sync signal by varying the frequency of the return section of the horizontal sync signal to the fixed vertical sync signal.

Here, since the return section of the horizontal sync signal is a section without image data, changing the frequency of the return section of the horizontal sync signal does not affect the displayed image, so that the entire system is stable.

FIG. 6A illustrates a horizontal driving cycle of an optical scanner according to an active section of a horizontal sync signal, and FIG. 6B illustrates a horizontal driving cycle of an optical scanner according to a return section of a general horizontal sync signal, and FIG. 6C illustrates an embodiment of the present invention. FIG. 7 is a diagram illustrating a horizontal driving cycle of an optical scanner according to a return section of a horizontal synchronizing signal. FIG.

As shown in FIG. 6A, the horizontal driving cycle of the optical scanner according to the active period of the horizontal synchronizing signal is the same as in the conventional system.

However, as shown in FIGS. 6B and 6C, although the horizontal driving cycle of the optical scanner according to the return section of the horizontal synchronization signal has been kept constant, it can be seen that the present invention is changed to have an irregular amplitude. have.

Accordingly, in the conventional system, since the horizontal driving cycle of the optical scanner according to the return section of the horizontal synchronization signal is kept constant, the vertical synchronization signal is varied with respect to this, but the present invention provides a horizontal drive of the optical scanner according to the return section of the horizontal synchronization signal. By varying the cycle to have an irregular amplitude, the vertical synchronizing signal can be fixed.

As described above, the driving method of the optical scanner driving apparatus according to the present invention is as follows.

7 is a flowchart illustrating a method of driving an optical scanner according to the present invention. As shown in FIG. 7, first, when the driving signal generator 110 applies the generated driving signal to the optical scanner 10, FIG. The optical scanner 10 starts driving to display an image on the screen.

Subsequently, the sensing unit 30 senses the driving of the optical scanner (S11), and the sensing signal processor 50 processes the sensed sensing signal (S13).

Here, the sensing signal processor 50 removes the noise of the sensed sensing signal and converts the sensing signal from which the noise is removed into a clock signal.

Next, the horizontal blank signal generator 70 generates a horizontal blank signal indicating an active section of the horizontal sync signal from the signal processed sensing signal (S15).

The synchronization signal adjusting unit 90 varies the return period of the horizontal synchronization signal according to the horizontal blank signal to synchronize the horizontal synchronization signal with the vertical synchronization signal of the fixed input image (S17).

Here, the synchronization signal adjusting unit 90 first synchronizes the active period of the horizontal synchronization signal to the active period of the vertical synchronization signal according to the horizontal blank signal.

Then, the frequency of the active section of the synchronized horizontal sync signal is counted, and then a difference value between the total frequency of the horizontal sync signal for one frame of the input image and the frequency of the active section of the counted horizontal sync signal is calculated.

Subsequently, the horizontal synchronization signal may be synchronized with the vertical synchronization signal of the fixed input image by increasing or decreasing the frequency of the return section of the horizontal synchronization signal according to the calculated difference value.

At this time, when the frequency is increased or decreased, the amplitude of the frequency may be irregular.

Lastly, the driving signal generator 110 generates a synchronization signal according to the adjusted horizontal and vertical synchronization signals and outputs the synchronization signal to the optical scanner so that the optical scanner is driven (S19).

The present invention operating as described above senses the horizontal synchronization signal of the optical scanner, generates a horizontal blank signal indicating the active period of the horizontal synchronization signal, and according to the horizontal blank signal, varying the return interval of the horizontal synchronization signal fixed input By synchronizing the horizontal synchronizing signal with the vertical synchronizing signal of the image, it is possible to stabilize the drive system of the optical scanner and improve the synchronization of video and audio.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

1 is a block diagram showing a driving device of an optical scanner according to the present invention;

FIG. 2 is a diagram illustrating a sensing signal processor of FIG. 1. FIG.

3 is a view illustrating a synchronization signal adjusting unit of FIG. 1.

4 is a view illustrating an adjustment unit of FIG. 3.

5A shows the synchronization of the horizontal and vertical frequencies of a typical optical scanner.

5b shows the synchronization of the horizontal and vertical frequencies of an optical scanner according to the invention;

6A is a diagram illustrating a horizontal driving cycle of an optical scanner according to an active period of a horizontal synchronization signal;

6B is a view illustrating a horizontal driving cycle of an optical scanner according to a return section of a general horizontal synchronization signal;

6C is a view illustrating a horizontal driving cycle of the optical scanner according to the return section of the horizontal synchronization signal of the present invention.

7 is a flowchart illustrating a method of driving an optical scanner according to the present invention.

Claims (12)

In the drive of the optical scanner for scanning an image on the screen, An optical scanner driven by a drive signal; A sensing unit configured to sense driving of the optical scanner; A sensing signal processor configured to process a sensing signal sensed by the sensing unit; A horizontal blank signal generator configured to generate a horizontal blank signal indicating an active period of a horizontal sync signal from the signal processed sensing signal; A synchronization signal adjusting unit configured to vary the return period of the horizontal synchronization signal to synchronize the horizontal synchronization signal with a vertical synchronization signal of a fixed input image according to the horizontal blank signal; And, And a driving signal generator for generating the driving signal and outputting the driving signal to the optical scanner according to the adjusted horizontal and vertical synchronizing signals. The method of claim 1, wherein the sensing signal processing unit, A noise removing unit removing noise of the sensing signal sensed by the sensing unit; And a clock signal converting unit converting the noise-sensed sensing signal into a clock signal. The method of claim 1, wherein the synchronization signal adjusting unit, A memory for storing an input video signal; A sync signal generator for generating horizontal and vertical sync signals from the stored video signals; The vertical synchronization signal is fixed to the synchronization signal generator, and the return period of the horizontal synchronization signal is varied according to the horizontal blank signal input from the horizontal blank signal generator to synchronize the horizontal synchronization signal to the fixed vertical synchronization signal. Optical scanner driving apparatus comprising a control unit to make. The method of claim 3, wherein the adjustment unit, A synchronizer configured to synchronize an active section of the horizontal sync signal to an active section of the vertical sync signal according to the horizontal blank signal; A counter unit for counting a frequency of an active section of the synchronized horizontal synchronization signal; And a frequency varying unit configured to vary a frequency of a return section of the horizontal synchronizing signal according to the counted frequency. The optical scanner driving apparatus of claim 4, wherein the active period of the horizontal synchronization signal is a time when the vertical synchronization signal for one frame of the input image falls from high to low. The optical scanner driving apparatus of claim 4, wherein the return period of the horizontal synchronization signal is a time when the vertical synchronization signal for one frame of the input image rises from low to high. The method of claim 4, wherein the frequency variable portion, A calculator configured to calculate a difference value between a total frequency of a horizontal sync signal for one frame of the input image and a frequency of an active period of the counted horizontal sync signal; And a frequency increase / decrease unit for increasing or decreasing the frequency of the return section of the horizontal synchronization signal according to the calculated difference value. The optical scanner driving apparatus of claim 7, wherein the frequency increasing or decreasing unit increases or decreases the frequency so that the amplitude of the frequency is irregular. In the driving method of the optical scanner for scanning an image on the screen, Applying a driving signal to the optical scanner; Sensing driving of the optical scanner; Signal processing the sensed sensing signal; Generating a horizontal blank signal representing an active period of a horizontal synchronization signal from the signal processed sensing signal; Synchronizing the horizontal synchronization signal with a vertical synchronization signal of a fixed input image by varying a return section of the horizontal synchronization signal according to the horizontal blank signal; And, And generating the driving signal according to the adjusted horizontal and vertical synchronizing signals and outputting the driving signal to the optical scanner. The method of claim 9, wherein the processing of the sensed sensing signal comprises: Removing noise of the sensed sensing signal; And converting the sensing signal from which the noise is removed into a clock signal. 10. The method of claim 9, wherein, in response to the horizontal blank signal, varying a return section of the horizontal synchronization signal to synchronize the horizontal synchronization signal to a vertical synchronization signal of a fixed input image. Synchronizing an active section of the horizontal synchronization signal to an active section of the vertical synchronization signal according to the horizontal blank signal; Counting a frequency of an active period of the synchronized horizontal synchronization signal; Calculating a difference value between an entire frequency of a horizontal synchronization signal and a frequency of an active period of the counted horizontal synchronization signal for one frame of the input image; And increasing or decreasing a frequency of a return section of the horizontal synchronizing signal according to the calculated difference value. 12. The method of claim 11, wherein when the frequency is increased or decreased, the amplitude of the frequency is irregular.

Images