WO2013160982A1

WO2013160982A1 - Image generating apparatus

Info

Publication number: WO2013160982A1
Application number: PCT/JP2012/060812
Authority: WO
Inventors: 義博花田
Original assignee: パイオニア株式会社
Priority date: 2012-04-23
Filing date: 2012-04-23
Publication date: 2013-10-31

Abstract

Provided is an image generating apparatus wherein image display mode can be changed with a simple configuration. A luminous flux generated on the basis of image data is radiated from a light source by driving an optical mirror in the two-dimensional directions, i.e., the main scan direction and the sub-scan direction. At that time, the polarization range of the luminous flux to be polarized corresponding to an optical mirror drive quantity is changed by adjusting optical mirror drive power in the main scan direction or the sub-scan direction.

Description

Image generation device

The present invention relates to an image generation apparatus.

As a method of displaying an image by a digital device, for example, there is a method of displaying an image by irradiating a display target with laser light based on the image. Since the laser beam is excellent in directivity, it is clear, and since the laser beam has an ideal single wavelength spectrum distribution, an image excellent in color rendering can be displayed.

When displaying an image using laser light, the laser light is irradiated onto an optical mirror, and the optical mirror is driven at high speed in a two-dimensional direction by a mirror driving device, thereby scanning the laser light on a display target. There is something.

As an example of the optical mirror at this time, there is a MEMS (Micro-Electro-Mechanical Systems) mirror using semiconductor technology. By using this MEMS mirror, a digital device equipped with an image display function can be downsized and improved in performance. It becomes possible.

As described above, it may be desired to change the display form of the image to be displayed on the display target in accordance with its use and role. For example, it is necessary to enlarge and reduce the image.

Patent Document 1 shown below discloses a technique for changing the size of an image without using an optical zoom lens.

In Patent Document 1, an image signal of an image to be displayed is stored in a frame memory in units of frames, and a dot clock having a clock cycle corresponding to the pixel position of the image is generated, so that each dot clock is stored in the frame memory. A technique for reading out stored image signals in units of pixels and generating and outputting image signals of each color (R, G, B), and changing the light beam emission timing according to the generated dot clock cycle to change the image size. It has changed.

JP 2008-197205 A

In a technique that requires changing the clock period for driving the optical mirror when enlarging and reducing the image to be displayed, it is necessary to control the oscillation frequency of the clock for changing the clock period. An apparatus (for example, a circuit) for performing this control process is required.

In addition, when drawing in a narrow range in each pixel (pixel), it is necessary to control the pixel clock at high speed, and output image data (pixel data) for each pixel at high speed accordingly. It becomes necessary to do.

Therefore, in view of the problems as described above, an object of the present invention is to provide an image generation apparatus that can change an image display form with an easy configuration.

In order to achieve the above object, the invention of claim 1 is directed to a polarizer that polarizes a light beam emitted from a light source by driving in a two-dimensional direction, and the driving by adjusting a driving amount of the polarizer. Polarization range changing means for changing the polarization range of the luminous flux polarized according to the amount.

The block diagram which shows the detailed structure of the image generation apparatus in embodiment of this invention. FIG. 4 is a drive waveform diagram showing a vibration state in the main scanning direction when a mirror is driven in the polarizer shown in FIG. 1. FIG. 6 is a drive waveform diagram showing a vibration state in the sub-scanning direction when a mirror is driven in the polarizer shown in FIG. 1. The figure which shows the detailed structure of the mirror drive control part shown in FIG. The figure which shows the circuit structure of the absolute value detection part, peak hold part, and LPF part which comprise the main scanning amplitude detection part shown in FIG. The figure which shows the state of the amplitude signal output by the circuit structure of the main scanning amplitude detection part as shown in FIG. The figure which shows the light intensity of a laser beam. The figure which shows the production | generation process of the synchronizing signal with respect to the amplitude signal of a main scanning direction. The figure which shows the production | generation process of the synchronizing signal with respect to the amplitude signal of a subscanning direction. The other example of the block diagram which shows the detailed structure of the image generation apparatus in embodiment of this invention. The other example of the block diagram which shows the detailed structure of the image generation apparatus in embodiment of this invention.

Hereinafter, an embodiment of an image generation apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a configuration diagram showing a detailed configuration of an image generation apparatus according to an embodiment of the present invention.

In FIG. 1, the image generation apparatus controls a polarizer 100 configured by a reflector (hereinafter simply referred to as “mirror”) and a driving device that drives the mirror, and driving performed by the driving device in the polarizer 100. A mirror driving control unit 101 for detecting the amplitude of the mirror in the main scanning direction based on the driving position of the polarizer 100 in the main scanning direction, and a driving position of the polarizer 100 in the sub scanning direction. A sub-scanning amplitude detection unit 103 that detects the amplitude of the mirror in the sub-scanning direction, a video processing unit 104 that processes an image based on the image data instructed to be displayed as a video, and a light beam (hereinafter, referred to as an image). , Referred to as “laser light”), a laser light driving unit 105 that performs processing for driving a light source that emits light, and laser light irradiation That the laser light source 106 is a light source constituted by including the collimator lens 107 for diffusing converging a laser beam as a cylindrical parallel light in a predetermined range.

As described above, the polarizer 100 includes a mirror that reflects (emits) laser light emitted from the laser light source 106 via the collimator lens 107 and a drive device that drives the mirror.

The polarizer 100 scans the display object (screen) by projecting an image by a pixel composed of a rectangle (rectangle) whose inner angles are all right angles, such as a rectangle and a square, by polarizing the laser beam. As a scanning form at this time, there is a Lissajous scan for drawing a Lissajous figure.

Further, the mirror is formed by a gimbal structure having an outer frame portion and a rectangular reflecting portion having a fixed area, and the outer frame portion and the reflecting portion can be rotated by a spring which is an elastic member. It is supported by. Specifically, the outer frame portion is supported by a spring that rotates about the main scanning direction (horizontal direction) as the central axis, and the reflecting portion is the central axis about the sub-scanning direction (vertical direction) orthogonal to the main scanning direction. Is supported by a rotating spring.

By utilizing the restoring force of these springs, the outer frame portion and the reflecting portion are driven by rotating the spring along the central axis, and the polarizer 100 is made up of a mirror (more specifically, a reflecting portion). ) Can be reflected (emitted) within a predetermined range.

This mirror is driven by a drive device, and the drive device generates an electrostatic force by applying a voltage to the mirror (generating a potential difference) to drive the mirror to vibrate slightly. Do. Of course, the present invention is not limited to the slight vibration of the mirror caused by such a piezoelectric effect, and may be configured to cause the fine vibration caused by an electromagnetic force generated by using a coil or the like.

The polarizer 100 also includes a sensor (position sensor) that detects the amount of displacement of the mirror, and this position sensor detects the amount of displacement of the mirror driven by the driving device.

In the polarizer 100 having such a configuration, a driving waveform representing a vibration state in the main scanning direction when the mirror is slightly vibrated by the driving device is shown in FIG. 2, and a driving waveform representing the vibration state in the sub scanning direction is shown in FIG. 3 shows.

FIG. 2 is a diagram showing a drive waveform representing a vibration state in the main scanning direction when the mirror is driven in the polarizer 100 shown in FIG.

FIG. 2 shows a vibration state in the main scanning direction, and the vibration state shown in FIG. 2 is an example of a drive waveform that periodically changes, and is a sine having the following (formula). It is a wave.
θ = a · sinωxt (formula)

In this case, “ωx” indicates the driving angular frequency in the main scanning direction, “t” indicates the elapsed time, and “a” indicates the amplitude that is the maximum deviation from the central axis of the driving waveform. This shows the swing angle magnification.

Further, “θ” obtained by the above (expression) by giving these variables indicates an angle (a swing angle) that is swung when the mirror is swung in the main scanning direction.

FIG. 2 shows three sine waves as examples of the vibration state in the main scanning direction of the mirror indicated by the sine waves.

Each of the sine waves indicating these three vibration states shows an example in which the vibration angular frequency and time are the same (that is, the period is the same), and only the amplitude indicating the swing angle magnification in the main scanning direction is different.

The first sine wave has a swing angle magnification indicated by amplitude “1”, and the second sine wave has a swing angle magnification indicated by amplitude larger than the amplitude “1” of the first sine wave. The third sine wave has a small amplitude “0.8”, and the swing angle magnification indicated by the amplitude is an amplitude “1.2” larger than the amplitude “1” of the first sine wave.

In this manner, by creating sine waves having different amplitudes (swing angle magnifications) for one sine wave, the swing angle “θ” in the main scanning direction output by these sine waves is the sine wave. This is proportional to the swing angle magnification “a” which is the amplitude. That is, when the amplitude (the swing angle magnification “a”) is changed, the mirror swing angle “θ” is changed in proportion.

For example, when the amplitude of the swing angle magnification is amplified from “1” to “1.2”, the swing angle is also increased from “1” to “1.2” in proportion to the image size. On the contrary, when the amplitude of the swing angle magnification is reduced from “1” to “0.8”, the swing angle is also changed from “1” to “1.2”. By decreasing in proportion to 0.8, the image size is also reduced to 0.8 times.

In other words, changing the swing angle indicates that the range irradiated by the mirror is changed, and the image that is visually recognized when the amplitude of the swing angle magnification is amplified. The angle is widened, and when the amplitude of the swing angle magnification is reduced, the view angle to be viewed is narrowed.

Further, in this polarizer 100, a light beam irradiation time (in other words, an image display time for displaying an image) for irradiating a laser beam to a mirror driven with a swing angle in a vibration state as shown in FIG. 2 is set in advance. Is in a fixed state.

The light beam irradiation time for irradiating the laser beam at this time can be determined by the size of the effective area of the display target that displays the image based on the image data. For example, the blanking period during which the image is not displayed is the laser. When the irradiation time is 10% (10 percent) before and after the irradiation time, the other effective period excluding the blanking period is the irradiation time.

In the example shown in FIG. 2, the time “t” of one cycle is set to “1” of the unit time, and the unit time in this one cycle is divided into 20 equal parts. Then, if the time when the absolute value of the amplitude in the sine wave indicating the vibration state of the mirror is the maximum is the time when the laser beam irradiation can be started (t = 0), it is one of 20 equal parts. The laser beam is not irradiated on the mirror until the time of (twentieth) has elapsed (until t is changed from “0” to “T1”), which is 10% of the first half of the irradiation time that is the blanking period. Is in a state.

Also, the period from “T1” (1/20) to “T2” (9/20) after the blanking period has elapsed is an effective period, which is an irradiation time irradiated with laser light. Since the period from “T2” (9/20) to “T3” (10/20) is the blanking period of 10% of the latter half of the irradiation time in the half cycle, the laser beam is irradiated onto the mirror. Not in a state.

Furthermore, since “T3” (10/20) to “T4” (11/20) is a blanking period that is the first 10% of the irradiation time in the other half cycle, the laser beam is applied to the mirror. Not in a state.

In addition, the period from “T4” (11/20) to “T5” (19/20) after the blanking period has elapsed is an effective period, which is an irradiation time irradiated with laser light.

The period from “T5” (19/20) to the last one (20/20) of one cycle divided into 20 (period until t becomes “0”) Since the blanking period is 10% of the latter half of the irradiation time in the half cycle, the laser beam is not irradiated onto the mirror.

FIG. 3 is a diagram showing a drive waveform representing a vibration state in the sub-scanning direction when the mirror is driven in the polarizer 100 shown in FIG.

In FIG. 3, the vibration state in the sub-scanning direction is represented by a saw waveform.

Similarly to the vibration state in the main scanning direction shown in FIG. 2, three waveforms are shown as examples of the vibration state in the sub-scanning direction of the mirror.

The three sawtooth waveforms are also shown in an example in which all three waveforms have the same period and differ only in the amplitude indicating the swing angle magnification in the sub-scanning direction.

In the first sawtooth waveform, the swing angle magnification indicated by the amplitude is “1”, and in the second sawtooth waveform, the amplitude “0.8” smaller than the amplitude “1” of the first sawtooth waveform. The third sawtooth waveform has an amplitude “1.2” whose amplitude is larger than the amplitude “1” of the first sawtooth waveform.

In this way, by creating saw waveforms having different amplitudes (swing angle magnifications) for one saw waveform, the swing angle in the sub-scanning direction output by these saw waveforms is the amplitude of the saw waveform. It is proportional to the swing angle magnification. That is, when the amplitude is changed, the swing angle of the mirror is changed in proportion.

Further, in this polarizer 100, a light beam irradiation time (in other words, an image display time for displaying an image) for irradiating a laser beam to a mirror driven with a swing angle in a vibration state as shown in FIG. 3 is preset. Is in a fixed state. In the example shown in FIG. 3, T6 to T7 is the first half blanking period in the half cycle, T7 to T8 is the irradiation time, and T8 to T9 is the second blanking period in the half cycle. is there.

In this blanking period, the laser beam is not irradiated to the mirror, and in the irradiation time, the laser beam is irradiated to the mirror.

Note that the polarizer 100 reflects the laser beam to a predetermined range by driving the outer frame portion and the reflecting portion, and therefore the irradiation time of the laser beam in the half cycle shown in FIG. The irradiation time of the laser beam in the half cycle shown shows the same time.

Moreover, the waveforms shown in FIGS. 2 and 3 are merely examples of vibration states when driving the mirror in the polarizer 100, and are not limited to these waveforms. Good.

The polarizer 100 that vibrates as described above detects the main scanning position and the sub-scanning position of the mirror when the mirror is driven by the driving device using the position sensor.

The position sensor outputs the main scanning position corresponding to the detected swing angle in the main scanning direction to the main scanning amplitude detection unit 102 and the mirror drive control unit 101, and outputs the sub scanning position corresponding to the swing angle in the sub scanning direction. The data is output to the scanning amplitude detector 103. The position information of the main scanning position and the sub-scanning position at this time is expressed by the mirror amplitude signal.

Next, the mirror drive controller 101 shown in FIG. 1 drives the mirror by controlling the drive device of the polarizer 100. The mirror drive control unit 101 at this time performs drive control for each dimension by outputting the mirror drive signal in the main scanning direction and the mirror drive signal in the sub-scanning direction to the drive device of the polarizer 100.

The mirror drive control unit 101 has a storage area (a “target amplitude signal storage unit” to be described later) configured by a ROM (Read Only Memory) or the like, and the mirror of the polarizer 100 reflects in this storage area. Thus, information according to the display size (target display size) of the image based on the image data to be displayed and information that changes the mirror swing angle is stored.

This information is specified by an input source that inputs image data to the video processing unit 104, and the display size of an image to be displayed by a target amplitude information calculation unit (not shown) of the mirror drive control unit 101. Is calculated based on

Based on information stored in this storage area (a “target amplitude signal storage unit” to be described later), the mirror drive control unit 101 changes the vibration state. For example, in the examples shown in FIGS. ) And the image of the designated display size is scanned by the polarizer 100 and displayed.

Of course, without being limited to this, as described later, the vibration state using information based on the difference between the target display size and the current display size of the image displayed before displaying the image at the target display size. May be changed.

The detailed configuration of the mirror drive control unit 101 is shown in FIG. 4 and will be described later.

Subsequently, the main scanning amplitude detection unit 102 shown in FIG. 1 includes an absolute value detection unit 102a, a peak hold unit 102b, and an LPF unit 102c. The main scanning amplitude output from the position sensor of the polarizer 100 is provided. When the main scanning position of the mirror in the direction is received, the amplitude is detected from a waveform representing the main scanning position in time series.

The amplitude at this time represents the swing angle of the mirror as described above, and this swing angle is obtained when the mirror is driven with a drive amount based on the drive signal in the main scanning direction output from the mirror drive control unit 101. This corresponds to the amount of displacement of the mirror.

Similarly to the main scanning amplitude detection unit 102, the sub-scanning amplitude detection unit 103 includes an absolute value detection unit 103a, a peak hold unit 103b, and an LPF unit 103c. When the output sub-scanning position of the mirror in the sub-scanning direction is received, the amplitude is detected from a waveform representing the sub-scanning position in time series.

This amplitude similarly represents the mirror swing angle as described above, and this swing angle is obtained when the mirror is driven with a drive amount based on the drive signal in the sub-scanning direction output from the mirror drive control unit 101. This corresponds to the amount of displacement of the mirror.

The absolute value detection unit 102a, the peak hold unit 102b, and the LPF unit 102c constituting the main scanning amplitude detection unit 102 are configured by a circuit as shown in FIG. 5, and FIG. The signal information output when processing is performed by the absolute value detection unit 102a, the peak hold unit 102b, and the LPF unit 102c configured by such a circuit is shown.

The absolute value detection unit 102a shown in FIG. 1 and the absolute value detection circuit shown in FIG. 5 are amplitude signals indicating the amount of displacement output from the position sensor of the polarizer 100, and are amplitude signals having the waveform of point a shown in FIG. Is received, the process of detecting the absolute value of the amplitude signal is performed.

The amplitude signal generated by this absolute value detection processing is an amplitude signal having a point b waveform shown in FIG. 6, and the amplitude signal having the point b waveform is input to the peak hold unit 102b. This point b waveform is a mountain-shaped waveform.

Next, the peak hold unit 102b shown in FIG. 1 and the peak hold circuit shown in FIG. 5 are obtained from the waveform of the point b in FIG. 6 output from the absolute value detection unit 102a shown in FIG. 1 and the absolute value detection circuit shown in FIG. The peak hold process is performed by receiving the amplitude signal. This peak hold process is a process that continues to hold an amplitude signal composed of an arbitrary value (for example, a voltage value) by suppressing a drop in the voltage value indicated by the amplitude signal output by the absolute value detection process.

The amplitude signal generated by the peak hold process is an amplitude signal having a point c waveform shown in FIG. 6, and the amplitude signal having the point c waveform is input to the LPF unit 102c. This point c waveform is a waveform proportional to the voltage at point b.

The LPF unit 102c and the LPF circuit shown in FIG. 5 receive the amplitude signal composed of the point c waveform of FIG. 6 output from the peak hold unit 102b shown in FIG. 1 and the peak hold circuit shown in FIG. Process. This filtering process is a process of eliminating (cutting) an amplitude signal having a predetermined frequency or higher. Of course, an HPF (high pass filter) may cut the amplitude signal below a predetermined frequency, or an LPF (low pass filter) and HPF may cut the amplitude signal above and below the predetermined frequency simultaneously. May be.

This filtering process is particularly effective when a constant value is continuously held by the peak hold process, and the value indicated by the amplitude signal generated by the peak hold process is constant. It is not always necessary to perform this filtering process.

The amplitude signal generated by the above filtering process is an amplitude signal having a point d waveform shown in FIG. 6, and the main scanning amplitude detection unit 102 sends the point d waveform amplitude signal to the mirror drive control unit 101. Send it out. The waveform at the point d is amplitude information in the main scanning direction (hereinafter also referred to as “main scanning amplitude information”) indicating the voltage value of the displacement amount of the mirror output from the polarizer 100. That is, the main scanning amplitude information is input from the main scanning amplitude detection unit 102 to the mirror drive control unit 101.

Also, the absolute value detection unit 103a, the peak hold unit 103b, and the LPF unit 103c constituting the sub-scanning amplitude detection unit 103 can also be configured by a circuit as shown in FIG.

In the absolute value detection unit 103a as an amplitude signal detected by the sub-scanning amplitude detection unit 103, the mirror of the polarizer 100 is driven in the sub-scanning direction (vertical direction) by a sawtooth waveform as shown in FIG. Although not shown, the point a waveform shown in FIG. 6 is a sawtooth waveform.

The waveform of the sawtooth waveform point a waveform output from the absolute value detector 103a is the same waveform as the point a waveform. This indicates that the waveform does not change before and after detecting the absolute value because the input point a waveform is constituted by a positive number. Therefore, the sub-scanning amplitude detection unit 103 is not provided with the absolute value detection unit 103a, the peak hold unit 103b, and the LPF unit 103c as shown in the sub-scanning amplitude detection unit 103 of FIG. May be configured by the peak hold unit 103b and the LPF unit 103c.

Upon receiving this, the peak hold unit 103b performs a peak hold process on the point b waveform (point a waveform).

The peak hold unit 103b outputs the amplitude signal subjected to the peak hold process to the LPF unit 103c, and the LPF unit 103c performs a filtering process on the amplitude waveform subjected to the peak hold process.

Thereby, the sub-scanning amplitude detection unit 103 sends the scanning amplitude information in the sub-scanning direction (hereinafter referred to as “sub-scanning amplitude information”) to the mirror drive control unit 101. That is, the sub-scanning amplitude information is input from the sub-scanning amplitude detection unit 103 to the mirror drive control unit 101.

In this way, in the mirror drive control unit 101 to which the scanning amplitude information of the main scanning amplitude information and the sub-scanning amplitude information is input, the amplitude information at the target display size of the image to be displayed on the display target, the input scanning amplitude information, and A drive signal indicating a drive amount for driving the mirror of the polarizer 100 is generated and sent to the polarizer 100 with an amplitude (a swing angle) corrected (added or subtracted) by the difference amount.

The mirror drive control unit 101 also sends to the video processing unit 104 synchronization signals in the main scanning direction and the sub-scanning direction that are generated based on the generated drive signal.

Hereinafter, a detailed configuration of the mirror drive control unit 101 will be described with reference to FIG.

In FIG. 4, the mirror drive control unit 101 includes a target amplitude information storage unit 101a, an A / D converter 101b, a difference detection unit 101c, a swing angle adjustment calculation unit 101d, a drive signal generation unit 101e, a comparator 101f, and a synchronization signal generation unit 101g. It is comprised and comprises.

When the comparator 101f receives the mirror amplitude signal representing the main scanning position corresponding to the swing angle in the main scanning direction detected by the position sensor of the polarizer 100, the comparator 101f detects the amplitude based on the predesignated information. Predetermined amplitude information is generated from the signal.

For example, when the mirror amplitude signal as shown in FIG. 8A is input, the comparator 101f changes the detection state of the amplitude signal before and after the intersection with the time axis as shown in FIG. 8B. Generate amplitude information.

When the comparator 101f generates the amplitude information, the comparator 101f sends the amplitude information to the synchronization signal generation unit 101g.

Subsequently, when the A / D converter 101b receives the scanning amplitude information input from the main scanning amplitude detection unit 102 and the sub-scanning amplitude detection unit 103 shown in FIG. 1, the A / D converter 101b receives the received scanning amplitude information. Convert from analog signal to digital signal. The scanning amplitude information received by the A / D converter 101b at this time is a voltage value based on the amount of displacement detected by the position sensor of the polarizer 100.

Next, the A / D converter 101b sends scan amplitude information including the converted digital signal to the difference detection unit 101c.

Thus, when the difference detection unit 101c receives the scanning amplitude information transmitted from the A / D converter 101b, the difference detection unit 101c converts the target amplitude information, which is necessary for displaying an image and is information about the target amplitude, to the target amplitude. Read from the information storage unit 101a. The target amplitude information stored in the target amplitude information storage unit 101a is a voltage value necessary for driving the mirror of the polarizer 100.

Then, the difference detection unit 101c uses the read target amplitude information and the scanning amplitude information received from the A / D converter 101b to detect an amplitude difference amount in these pieces of information. That is, the difference amount between these voltage values is detected.

The difference detection unit 101c that has detected the difference amount in this way sends the detected difference amount to the swing angle adjustment calculation unit 101d.

The swing angle adjustment calculation unit 101d from which the difference amount is sent from the difference detection unit 101c performs calculation processing for calculating the amplitude amount for adjusting the swing angle of the mirror according to the difference amount. In other words, the amount of amplitude for driving the mirror is calculated by this calculation process.

When the adjusted swing angle (amplitude) is calculated by the calculation processing in the swing angle adjustment calculation unit 101d, the swing angle adjustment calculation unit 101d sends information about the calculated swing angle to the drive signal generation unit 101e. In this drive signal generation unit 101e, the drive amount for driving the mirror, which is necessary for adjusting the mirror swing angle to the transmitted swing angle, is specified based on the transmitted swing angle information. A drive signal is generated.

In the drive signal generation unit 101e, the drive signal in the main scanning direction and the sub scanning direction generated by performing arithmetic processing for adjusting the swing angle based on the scanning amplitude information in the main scanning direction and the scanning amplitude information in the sub scanning direction. The drive signal is sent to the polarizer 100. Thereby, the driving device of the polarizer 100 drives the spring supporting the outer frame portion of the mirror based on the driving signal based on the driving signal in the main scanning direction.

Also, the drive device for the polarizer 100 drives the spring that supports the reflecting portion of the mirror that constitutes the polarizer 100 based on the drive signal in the sub-scanning direction. That is, the polarizer 100 drives the main scanning direction and the sub-scanning direction with a driving amount specified by the driving signal from the driving signal generation unit 101e.

Note that the main scanning direction of the polarizer 100 in the present embodiment is driven by a driving waveform consisting of a sine wave as shown in FIG. 2, and therefore, the main scanning direction is particularly driven by resonance.

Also, the drive signal generation unit 101e sends the generated drive signal in the sub-scanning direction to the synchronization signal generation unit 101g.

The synchronization signal generation unit 101g receives the sub-scanning drive signal sent from the drive signal generation unit 101e, and generates a synchronization signal in the sub-scanning direction (hereinafter referred to as “sub-scanning synchronization signal”) based on the sub-scanning drive signal. At the same time, a synchronization signal in the main scanning direction (hereinafter referred to as “main scanning synchronization signal”) is generated based on the amplitude information received from the comparator 101f.

The synchronization signal generation unit 101g receives amplitude information in the main scanning direction as shown in FIG. 8B from the comparator 101f, thereby generating a main scanning synchronization signal having the same signal format as the amplitude information. A main scanning synchronization signal as shown in FIG. 8C may be generated.

The main scanning synchronization signal shown in FIG. 8C is a signal in which a point that intersects the time axis in the amplitude signal in the main scanning direction as shown in FIG. 8A input to the comparator 101f is designated as a synchronization timing. is there.

Further, the synchronization signal generation unit 101g generates a sub-scanning synchronization signal as shown in FIG. 9B when a sub-scanning drive signal as shown in FIG. 9A is input from the drive signal generation unit 101e. To do.

The sub-scanning synchronization signal shown in FIG. 9B is a signal that designates a point in contact with the time axis as a synchronization timing with respect to the sawtooth waveform sub-scanning drive signal.

The synchronization signal generation unit 101g sends the generated main scanning synchronization signal and sub-scanning synchronization signal to the video processing unit 104 shown in FIG.

The video processing unit 104 shown in FIG. 1 to which the main scanning synchronization signal and the sub-scanning synchronization signal have been sent from the mirror drive control unit 101 in this way processes an image as a video for each pixel information of the input image data ( Tone correction).

The video processing unit 104 outputs image information in the image to the laser beam driving unit 105 at a synchronization timing based on these synchronization signals.

Thereby, the laser light driving unit 105 generates a signal (for example, light intensity, gradation signal, etc.) related to the laser light emitted from the laser light source 106 and instructs the laser light source 106 to irradiate the laser light.

A laser light source unit is constituted by the laser light source 106 and the collimator lens 107, and the laser light source 106 is composed of RGB (Red, Green, Blue) primary colors based on information on the laser light instructed from the laser light driving unit 105. It is a light source that generates laser light of at least one of the three colors of laser light.

The collimator lens 107 is an optical element that refracts the laser light emitted from the laser light source 106 and converts it into parallel light that is substantially parallel to the optical axis. )) Is irradiated with a laser beam (light beam).

The collimator lens 107 can be moved on the optical axis by a stepping motor in response to an instruction from a control device (not shown) that controls the laser light source unit. The collimator lens 107 is moved by the stepping motor. Enlargement / reduction processing is performed to enlarge or reduce the range irradiated with laser light (hereinafter referred to as “irradiation spot diameter”) by moving on the optical axis. In the example shown above, the collimator lens 107 is moved by the stepping motor. However, the present invention is not limited to this. For example, the diameter of the irradiation spot of the laser beam may be enlarged or reduced using an aperture.

When this aperture is used, the display size of the image can be reduced compared to the image before being reduced by narrowing the irradiation spot diameter.

In this way, by causing the collimator lens 107 to move on the optical axis to expand and contract the irradiation spot diameter, it is possible to suppress the occurrence of astigmatism in the irradiation spot.

The parallel light emitted by the collimator lens 107 is cylindrical, and by reducing the irradiation spot diameter, the circular range (circular area) irradiated by the cylindrical shape is reduced, and the irradiation spot diameter is enlarged. The circular range (circular area) irradiated by the cylindrical shape increases.

That is, if the irradiation range is reduced by reducing the irradiation spot diameter, the image becomes smaller than the image before the reduction, and if the irradiation range is enlarged by increasing the irradiation spot diameter, the image is not enlarged. It becomes larger than the image.

FIG. 7 is a diagram showing the light intensity distribution of the laser light source irradiated on the polarizer 100 from the laser light source unit including the laser light source 106 and the collimator lens 107 shown in FIG.

FIG. 7 is a cross-sectional view of laser light when the vertical axis indicates the intensity (light intensity) of the laser light and the horizontal axis indicates the state of the laser light distributed in the sub-scanning direction. The cross-sectional view of the laser beam shown in FIG. 7 is represented by a right and left symmetrical normal curve.

FIG. 7 further shows an irradiation spot corresponding to the light intensity of each laser beam. Since this irradiation spot is irradiated by the collimator lens 107 shown in FIG. 1 with cylindrical parallel light, the irradiation spot of the laser beam irradiated on the mirror of the polarizer 100 can be represented by a circle.

That is, the light intensity of each laser beam can be changed by moving the collimator lens 107 on the optical axis, and the irradiation spot diameter is changed accordingly.

The light intensity at this time is set to an intensity at which the visibility of the image can be ensured when the light is displayed (displayed) by the mirror of the polarizer 100 being emitted (reflected). For example, the light intensity is set to prevent the occurrence of a striped pattern in the image and ensure visibility.

As an example of the light intensity at this time, the light intensity at which the normal distribution of the other laser light (adjacent laser light) intersects at half the light intensity of the laser light emitted from the collimator lens 107 is set.

The second embodiment is another example of the first embodiment described above.

FIG. 10 is a configuration diagram showing a detailed configuration of the image generation device according to the embodiment of the present invention, and is a diagram similar to the configuration diagram of the image generation device shown in FIG.

The image forming apparatus shown in FIG. 1 described in the first embodiment shows an example in which a display target (screen) for displaying an image is a pixel formed of a rectangle (rectangle) whose inner angles are all right angles, such as a rectangle or a square. However, the configuration of the image generation apparatus shown in FIG. 10 shows a configuration that is particularly useful when the display target pixels for displaying an image are the same in all four sides and are rectangular (square) whose inner angles are all right angles. ing.

Hereinafter, the difference between the configuration of the image generation apparatus in FIG. 10 and the configuration of the image generation apparatus in FIG. For this reason, basically, the contents of the first embodiment described above are all attacked, and the same constituent elements will be described using the identification numbers used in the first embodiment.

In FIG. 10, the image generation apparatus includes a polarizer 100 including a mirror and a driving device that drives the mirror, a mirror drive control unit 101 that controls driving performed by the driving device in the polarizer 100, and the polarizer 100. A main scanning amplitude detecting unit 102 for detecting the amplitude of the mirror in the main scanning direction based on the driving position in the main scanning direction, a video processing unit 104 for processing an image based on the image data instructed to be displayed, and an image A laser light driving unit 105 that performs processing for driving a light source of laser light used for projection, a laser light source 106 that is a light source for irradiating the laser light, and the laser light is diffused and converged as cylindrical parallel light within a predetermined range. A collimator lens 107 is provided.

As described above, the polarizer 100 includes a mirror that reflects (emits) laser light emitted from the laser light source 106 via the collimator lens 107, and a drive device that drives the mirror. In both cases, a laser beam is scanned onto a display target (screen) on which an image is projected by rectangular (square) pixels having the same inner angles.

In this polarizer 100, the mirror is driven in the two-dimensional direction by driving the mirror in the main scanning direction in the vibration state as shown in FIG. 2 and in the sub-scanning direction in the vibration state as shown in FIG. Driven. Of course, the waveforms shown in FIGS. 2 and 3 are merely examples of vibration states when the mirrors in the polarizer 100 are driven, and are not limited to these waveforms. Good.

The driving device further detects a vibration signal indicating a voltage value corresponding to a swing angle in the main scanning direction of each mirror and a vibration signal indicating a voltage value corresponding to the swing angle in the sub-scanning direction when the mirror is driven. is doing. This driving device outputs an amplitude signal indicating a voltage value corresponding to the detected swing angle in the main scanning direction to the main scanning amplitude detection unit 102.

Since the pixel to be displayed is a square, the irradiation spot diameter of the circular laser beam by the cylindrical parallel light is changed by the amplitude signal in the main scanning direction.

Next, the mirror drive control unit 101 is configured as shown in FIG. 4 and drives the mirror by controlling the drive device of the polarizer 100. At this time, the mirror drive control unit 101 outputs the mirror drive signal in the main scanning direction and the mirror drive signal in the sub-scanning direction to the drive device of the polarizer 100 to drive and control each dimension. .

Subsequently, the main scanning amplitude detection unit 102 shown in FIG. 1 includes an absolute value detection unit 102a, a peak hold unit 102b, and an LPF unit 102c, in the main scanning direction output from the driving device of the polarizer 100. An amplitude signal indicating a voltage value corresponding to the swing angle is received, and the amplitude of the amplitude signal is detected.

The amplitude at this time represents the swing angle of the mirror as described above, and this swing angle is the amount of voltage applied to obtain the drive amount based on the drive signal in the main scanning direction output from the mirror drive control unit 101. Equivalent to. In other words, detecting the amplitude of the amplitude signal by the main scanning amplitude detector 102 means measuring the applied voltage amount.

The absolute value detection unit 102a performs processing for detecting the absolute value of the amplitude signal indicating the voltage value corresponding to the swing angle output from the driving device of the polarizer 100. Further, the peak hold unit 102b performs a peak hold process that suppresses the voltage drop stored in the capacitor by further power storage on the amplitude signal having the waveform at the point b in FIG. 6 output from the absolute value detection circuit. Further, the LPF unit 102c performs a filtering process to eliminate (cut) an amplitude signal having a predetermined frequency or higher with respect to the amplitude signal having the waveform at the point c in FIG. Output the waveform as shown.

This waveform at the point d is scanning amplitude information in the main scanning direction representing a voltage value proportional to the maximum amplitude of an amplitude signal indicating the voltage value of the driving force for driving the mirror.

The mirror drive control unit 101 shown in FIG. 10 has the configuration shown in FIG. 4, and drives the mirror of the polarizer 100 using the scanning amplitude information in the main scanning direction. The mirror drive control unit 101 according to the first exemplary embodiment performs arithmetic processing for adjusting the swing angle based on the scanning amplitude information in the main scanning direction and the scanning amplitude information in the sub-scanning direction, thereby driving the driving signal in the main scanning direction. (Main scanning drive signal) and a sub scanning direction driving signal (sub scanning driving signal) are generated. In the second embodiment, the main scanning direction scanning amplitude signal received from the main scanning amplitude detection unit 102 is used as a source. The main scanning drive signal and the sub-scanning drive signal are generated.

The mirror drive control unit 101 also generates a synchronization signal in the sub-scanning direction based on the sub-scanning drive signal, and performs main scanning based on the amplitude information based on the amplitude signal in the main scanning direction detected by the mirror position sensor. A direction synchronization signal is generated.

Then, the mirror drive control unit 101 sends the generated synchronization signal to the video processing unit 104.

A laser light source unit is constituted by the laser light source 106 and the collimator lens 107, and the laser light source 106 generates a laser beam of at least one color out of three colors of laser light composed of RGB (Red, Green, Blue) primary colors. It is. The collimator lens 107 is an optical element that refracts the laser light emitted from the laser light source 106 and converts it into parallel light that is substantially parallel to the optical axis. )) Is irradiated with a laser beam (light beam).

The collimator lens 107 can be moved on the optical axis by a stepping motor in response to an instruction from a control device (not shown) that controls the laser light source unit. The collimator lens 107 is moved by the stepping motor. Enlargement / reduction processing is performed to enlarge or reduce the range irradiated with laser light (hereinafter referred to as “irradiation spot diameter”) by moving on the optical axis. Of course, the irradiation spot diameter of the laser beam may be enlarged or reduced using an aperture.

The embodiment described above is an embodiment of the present invention, and is not limited to these examples, and can be appropriately modified and implemented without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 100 Polarizer 101 Mirror drive control part 101a Target amplitude information storage part 101b A / D converter 101c Difference detection part 101d Swing angle adjustment calculation part 101e Drive signal generation part 101f Comparator 101g Synchronization signal generation part 102 Main scanning amplitude detection part 102a Absolute value Detection unit 102b Peak hold unit 102c LPF unit (low-pass filter unit)
103 Sub-scanning amplitude detection section 103a Absolute value detection section 103b Peak hold section 103c LPF section (low-pass filter section)
104 Image processing unit 105 Laser light driving unit 106 Laser light source 107 Collimator lens

Claims

A polarizer that polarizes a light beam emitted from a light source by driving in a two-dimensional direction;
An image generation apparatus comprising: a polarization range changing unit configured to change a polarization range of the light beam polarized according to the drive amount by adjusting a drive amount of the polarizer.
The polarization range changing means is
The image according to claim 1, wherein the polarization range of the light beam is changed by adjusting a driving amount in at least one of the two-dimensional directions based on a display size of an image scanned by the polarization of the light beam by the polarizer. Generator.
The polarization range changing means is
The image generation according to claim 1, wherein a polarization range of the light beam is changed by adjusting a maximum deviation from a central axis in a waveform signal expressed when the light beam is polarized by the polarizer, based on a display size of the image. apparatus.
A displacement amount detecting means for detecting a displacement amount of the polarizer when the light beam is scanned in the polarization range by polarization by the polarizer;
The image generation apparatus according to claim 1, further comprising: a voltage value measurement unit that measures a voltage value required when the polarizer is polarized with the displacement detected by the displacement detection unit.
Absolute value detection means for detecting an absolute value signal from a waveform signal representing a vibration state of a light beam emitted from the light source by being driven at a constant period;
Further comprising value holding means for holding an arbitrary value in the absolute value signal detected by the absolute value detecting means,
The polarization range changing means is
The image generation apparatus according to claim 1, wherein a polarization range of the light beam is changed by adjusting a value held by the value holding unit.
The irradiation range expansion / contraction means for expanding / contracting the irradiation range of the light beam emitted from the light source to an irradiation range specified according to the polarization range of the light beam changed by the scanning range changing unit. The image generation apparatus according to any one of the above.