JP2014174359A - Scanning type light irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning type light transmission device capable of improving the degree of freedom of a light irradiation timing by suppressing the useless increase of a data transfer period.SOLUTION: A scanning type light irradiation device for performing light irradiation by scanning beam light includes: light sources 4a, 4b, and 4c for modulating and outputting beam light in accordance with irradiation data; a deflection element 8 for two-dimensionally scanning the beam light of the light sources; a first data storage part for storing the irradiation data generated in accordance with the operation of the deflection element in a first timing; and a second data storage part for storing the irradiation data stored by the first data storage part in a second timing when the light sources are driven. The first timing is set to an equal time interval, and the second timing is set to an unequal time interval, and determined in accordance with the irradiation position of the beam light corresponding to the operation of the deflection element.

Description

  The present invention relates to a scanning light irradiation apparatus that irradiates an irradiation surface with light source light using a light source capable of modulating output and a deflection element that performs two-dimensional scanning of the light source light.

  A light irradiation device that uses a small and highly efficient beam source that can be modulated, such as a semiconductor laser, and deflects the beam light using a MEMS mirror and performs two-dimensional scanning to display an image. It is attracting attention in that respect. In addition, this scanning light irradiation apparatus is considered to be applied to a sensor that measures the shape and distance of an object by detecting reflected light from the object scanned by light rays.

  For example, Patent Document 1 discloses an image projection apparatus that raster scans laser light using a MEMS mirror and projects an image on a screen. More specifically, Patent Document 1 focuses on the fact that the scanning speed of the horizontal scanning of the MEMS mirror that resonates and changes in a sine curve, and a technique for controlling the light source output so that the illuminance of the projected image is uniform. It is disclosed.

JP 2006-343397

  According to the technique described in Patent Document 1, the angle of a light beam is changed using a deflection element, and the output of the light source is modulated in accordance with the change to display image data. The desired amount of light can be irradiated to the place. This is advantageous when correcting distortion caused by a deflection element or an optical system in a projector application, and further correcting distortion due to the shape of the projection target. Further, when the technique described in Patent Document 1 is applied to a sensor, it is advantageous for improving the measurement position accuracy of the object.

  However, the above technique needs to modulate the light source at a higher speed in order to irradiate the light beam at an arbitrary place. For this reason, there is a problem in that the data transfer rate to the light source is increased, and as a result, the power consumption in the data processing unit is increased, and further the power consumption in the light source driver is increased.

  The present invention has been made to solve the above problems, and an object of the present invention is to improve the degree of freedom of light irradiation timing by suppressing an unnecessary increase in the data transfer period.

  In order to solve the above-described problems, the scanning light irradiation apparatus of the present invention has a light source driver drive timing asynchronous with a light source drive data transfer timing, and a setting freedom of a start time and an irradiation period for irradiation from the light source. Improved.

  More specifically, the scanning light irradiation apparatus for scanning and irradiating the light beam according to the present invention includes a light source that modulates and outputs the beam light according to irradiation data, and a deflection that two-dimensionally scans the beam light of the light source. An element, a first data holding unit that holds irradiation data generated corresponding to the operation of the deflection element at a first timing, and irradiation data held in the first data holding unit using the light source A second data holding unit that holds at a second timing for driving, the first timing is an equal time interval, the second timing is an unequal time interval, and the operation of the deflection element It is determined by the irradiation position of the beam light corresponding to.

  According to the present invention, an unnecessary increase in the transfer rate to the light source driver can be suppressed and the degree of freedom of light irradiation timing can be improved. Therefore, a scanning light irradiation apparatus that easily performs high-precision laser irradiation is provided. Can be provided.

1 is a diagram illustrating an overall configuration of Example 1. FIG. FIG. 3 is a diagram illustrating a configuration of a data conversion unit 2 according to the first embodiment. FIG. 6 is a diagram illustrating control operation timings according to the first embodiment. FIG. 6 is a diagram illustrating an overall configuration of Example 2. FIG. 6 is a diagram illustrating a configuration of a data conversion unit 2 according to a second embodiment. FIG. 10 is a diagram illustrating control operation timings according to the second embodiment. FIG. 6 is a diagram illustrating an overall configuration of Example 3. FIG. 10 is a diagram illustrating a configuration of a data conversion unit 2 according to a third embodiment. FIG. 10 is a diagram illustrating a configuration of a data conversion unit 2 according to a fourth embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an example of a configuration diagram of a light irradiation apparatus of the present embodiment. The light irradiation apparatus of this embodiment includes a data generation unit 1, a data conversion unit 2, a plurality of light source drivers (light source driver 1 (3a), light source driver 2 (3b), light source driver 3 (3c)), a plurality of light sources ( Light source 1 (4a), light source 2 (4b), light source 3 (4c)), deflection element control unit 6, deflection element driver 7, deflection element 8 and optical element group 5.

  The data generation unit 1 generates ray information to be irradiated by this apparatus in synchronization with the deflection element control unit 6 that controls the scanning operation of the deflection element 8 such as a MEMS mirror. For example, when the present apparatus is used for image display, the data generated by the data generation unit 1 is generated based on image data input from the outside, and based on image data generated by itself. May be generated.

  The data conversion unit 2 generates a plurality of light source drivers (light source driver 1 (3a), light source driver 2 (3b), light source driver 3 (3c)) / light source generated and transmitted by the data generation unit 1 Conversion is performed so as to correspond to (light source 1 (4a), light source 2 (4b), light source 3 (4c)). The light source drivers (light source driver 1 (3a), light source driver 2 (3b), light source driver 3 (3c)) drive the light source based on the data converted by the data conversion unit 2.

  Here, the light irradiation apparatus of the embodiment is composed of light sources (light source 1 (4a), light source 2 (4b), light source 3 (4c)) such as R, G, and B three-color semiconductor lasers. Is driven by a light source driver (light source driver 1 (3a), light source driver 2 (3b), light source driver 3 (3c)), but is not limited thereto.

  The deflection element control unit 6 generates a reference signal for operating the deflection element 8 synchronized with the data generation unit 1. The deflection element driver 7 drives the deflection element 8 two-dimensionally based on the reference signal generated by the deflection element control unit 6. Here, in the two-dimensional scanning of the deflection element 8, for example, the mirror is driven so as to resonate in the horizontal scanning direction, and the mirror is driven in the non-resonant operation in the vertical scanning direction.

  The beam light emitted from the light source is combined into one beam light by an optical element group including optical elements such as a dichroic mirror and a collimator lens, and guided to the deflection element 8. Then, the light beam direction is deflected by the deflecting element 8 as described above, and a light beam having a desired intensity is irradiated in a desired direction.

  Next, irradiation data output timing control will be described with reference to FIGS. By controlling the output timing with the configuration of the embodiment, the scanning beam position of the deflecting element 8 that resonates can be controlled. Specifically, when the deflecting element 8 is a MEMS mirror, the scanning speed decreases at the scanning end of the MEMS mirror resonance, so that the output timing interval is increased. Thereby, the interval between the scanning beam positions can be made constant regardless of the irradiation angle.

  The change in the beam scanning speed described above is caused by the resonance driving of the MEMS mirror, but is also caused by the change in the irradiation distance. In the light irradiation apparatus according to the embodiment, since the scanning beam is output from the deflection element 8 at a predetermined radiation angle, the irradiation distance of the scanning beam is different between the central portion and the end portion of the surface irradiation surface. The irradiation distance becomes the shortest at the center of the irradiation surface, and the irradiation distance becomes longer toward the end of the irradiation surface. For this reason, the scanning speed of the scanning beam increases toward the end of the irradiation surface, and the interval between the scanning beam positions increases. For this reason, the output timing is controlled also in the vertical direction in which the deflecting element 8 is in a non-resonant operation.

  Since the change in the irradiation distance described above also occurs due to the inclination of the irradiation surface, the output timing may be controlled by measuring the irradiation distance to the irradiation surface. At the position where the irradiation distance is long, the output timing interval is shortened.

  FIG. 2 is a configuration diagram showing an outline of the data conversion unit 2 of FIG. In the data conversion unit 2, the irradiation data generated in the data generation unit 1 is sequentially transferred in synchronization with the transfer clock by the shift register, so that it is parallelized according to the number of light sources and is irradiated at equal intervals. Data is generated.

  Further, the data conversion unit 2 holds and outputs data from the shift register by a latch register according to a latch signal. The output timing is controlled by changing the timing of the latch signal. The operation timing will be described with reference to FIG. FIG. 2 shows a configuration in which the latch signal is synchronized with the transfer clock. However, if the latch signal is a signal synchronized with the transfer clock, the synchronization of the latch signal is not necessary.

  FIG. 3 shows the relationship between the reference input data synchronized with the operation of the deflection element 8, the signal operation generated by the data generation unit 1 based on the reference input data, and the irradiation data in the light irradiation apparatus of this embodiment. It is an example of the timing chart shown. Here, in order to make the characteristics of this embodiment easier to understand, the data change period of the reference input data is made different from the timing determined by a multiple of the transfer clock × the number of light sources.

  According to this embodiment, for example, latch signals are generated at non-uniform intervals so that the scanning beam interval on the irradiation surface is constant, and data to be irradiated is generated at the same time in synchronization with the latch signal. By this, it is possible to improve the setting freedom of the start time and the irradiation period for irradiation from the light source. Since the reference input data is synchronized with the operation of the deflecting element 8, the degree of freedom in the light irradiation direction can be improved.

  In this embodiment, the data generation unit 1, the data conversion unit 2, the light source driver, the deflection element control unit 6, and the deflection element driver 7 are divided and expressed, but these are realized in the same IC. However, a part of it may be realized as a single IC.

  In the present embodiment, an example in which a latch signal transmitted at a predetermined time interval including an equal time interval and a data generation unit 2 (9) that transmits generated data synchronized with the latch signal will be described with reference to FIG. To do. FIG. 4 is a diagram showing the configuration of this embodiment. As described above, the light irradiation apparatus according to the present embodiment sends a latch signal at a predetermined time interval and sends data generated in synchronization with the data generation unit 2 (9), data timing correction unit 10, data conversion. Part 2, a plurality of light source drivers (light source driver 1 (3a), light source driver 2 (3b), light source driver 3 (3c)), a plurality of light sources (light source 1 (4a), light source 2 (4b), light source 3 (4c) )), A deflection element control unit 6, a deflection element driver 7, a deflection element 8, and an optical element group 5. Hereinafter, the data timing correction unit 10 will be described in detail.

  The data conversion unit 2 generates a plurality of light source drivers (light source driver 1 (3a), light source driver 2 (3b), light source driver 3 (3c)) / light source generated and transmitted by the data generation unit 1 Conversion is performed so as to correspond to (light source 1 (4a), light source 2 (4b), light source 3 (4c)). The light source drivers (light source driver 1 (3a), light source driver 2 (3b), light source driver 3 (3c)) drive the light source based on the data converted by the data conversion unit 2.

  Here, the light irradiation apparatus of the embodiment is composed of light sources (light source 1 (4a), light source 2 (4b), light source 3 (4c)) such as R, G, and B three-color semiconductor lasers. Is driven by a light source driver (light source driver 1 (3a), light source driver 2 (3b), light source driver 3 (3c)), but is not limited thereto.

  The deflection element control unit 6 generates a reference signal for operating the deflection element 8 synchronized with the data generation unit 1. The deflection element driver 7 drives the deflection element 8 two-dimensionally based on the reference signal generated by the deflection element control unit 6. Here, in the two-dimensional scanning of the deflection element 8, for example, the mirror is driven so as to resonate in the horizontal scanning direction, and the mirror is driven in the non-resonant operation in the vertical scanning direction.

FIG. 5 is a diagram illustrating an example of an internal configuration of the data timing correction unit 10. The data timing correction unit 10 includes an internal decoding unit, a counter unit, a latch signal generation unit, and a data encoding unit.
The internal decoding unit latches the input data sent from the data generation unit 2 (9) based on the input latch signal, and decodes the input data.
The counter unit counts the transfer clock. At this time, the counter unit is reset by the synchronization signal indicating the start timing of one line and / or the synchronization signal indicating the start timing of one screen, which is generated by the polarizing element control unit.
The latch signal generation unit receives the counter value of the counter unit and generates a latch signal based on a predetermined reference data timing.
The data encoding unit latches the data decoded by the internal decoding unit according to the latch signal generated by the latch signal generation unit.

  FIG. 6 shows a transfer clock received by the data timing correction unit 10, a latch signal transmitted by the data generation unit 12, generation data transmitted by the data generation unit 12, and internal decode data generated by the data timing correction unit 10. 5 is a timing chart showing operations of a latch signal and conversion data.

  Here, the internal decoder unit and the data encoder unit temporarily hold data based on the input latch signal and the latch signal generated by the latch signal generation unit. By adopting the double latch structure in this way, data can be transmitted at a timing synchronized with a latch signal at a predetermined time interval.

  According to the present embodiment, even when a control IC having a non-uniformly spaced latch signal and a data generation unit 12 that does not have a function of generating data synchronized therewith is used, high positional accuracy is realized. I can do things.

  Note that the components in the present embodiment may be realized as a single IC or may be constituted by a plurality of ICs.

  Next, an embodiment specific to a MEMS mirror that performs a resonance operation in which the deflection angle of the deflection element 8 changes in a sine wave shape will be described with reference to FIGS. FIG. 7 is a diagram showing the configuration of the embodiment, and the configurations of the data generation unit 3 (11) and the data conversion unit 12 are different from the embodiment shown in FIG. FIG. 8 is a configuration diagram showing the configuration of the data converter 12 in detail.

  The data conversion unit 12 of this embodiment shown in FIG. 8 generates image address data corresponding to the operation of the deflecting element 8 displaced in a sine wave shape. In order to realize this, the data conversion unit 12 includes an address counter, a sine wave conversion unit, a distortion correction unit, a scaling unit, and an image data generation unit.

The address counter counts the count value in accordance with the operation of the polarizing element.
The sine wave conversion unit converts the counter value of the address counter into sine wave-like data.
The distortion correction unit corrects distortion due to the shape of the projection surface based on the sine wave data converted by the sine wave conversion unit.
The scaling unit converts the distortion correction data generated by the distortion correction unit into a desired number of image data, and generates image address data.
The image data generation unit generates reference input data based on the image address data.

  According to this embodiment, the amount by which the angle of the deflection element 8 changes while the sine wave data is the same value is constant. Further, since the distortion correction data is converted in accordance with the shape of the projection surface, the amount of movement of the light spot between the distortion correction data having the same value is constant. By reading out the image data separately stored based on the address data, it becomes possible to display one pixel at equal intervals.

  In each of the above embodiments, the drive timing of the light source driver is made asynchronous with the transfer timing of the drive data of the light source, so that the setting time of the start time and the irradiation period irradiated from the light source is improved. is there. However, the configuration of the present invention is applicable not only to the correction of the irradiation timing but also to the following correction.

  The light irradiation apparatus to which the present invention is applicable is an apparatus that combines the light source light of the three light sources of the light source 1, the light source 2, and the light source 3 of FIG. The optical axes of the light source 1, the light source 2, and the light source 3 are set so as to coincide or satisfy a predetermined positional relationship. is there. Such a phenomenon leads to a decrease in accuracy such as a decrease in resolution.

  In this embodiment, a part of the configuration of the data timing correction unit 10 of the third embodiment is changed to eliminate the above phenomenon. In this embodiment, as shown in FIG. 9, an address correction unit that gives an address difference corresponding to the light beam angle correction amount of the light source 1, the light source 2, and the light source 3 to the subsequent stage of the scaling unit of the data timing correction unit 10 of FIG. To be provided. At this time, different address correction units are provided for the light source 1, the light source 2, and the light source 3, respectively, and image data corresponding to the address is read.

  According to the present embodiment, the image data generation timing of the light source 1, the light source 2, and the light source 3 is corrected in units of one pixel that is equally spaced by the sine wave conversion unit and the distortion correction unit. Therefore, an equal amount of correction can be performed over the entire area of the screen.

  Also, in this embodiment, when the image data is up-converted as a resolution more than twice that of the original image when converted to the image data address by the scaling unit, the image data in a unit smaller than the pixel of the original image. The angular deviation of the light sources 1 to 3 can be adjusted.

DESCRIPTION OF SYMBOLS 1 ... Data generation part, 2 ... Data conversion part, 3a, 3b, 3c ... Light source driver,
4a, 4b, 4c ... light source, 5 ... optical element group, 6 ... deflection element control unit, 7 ... deflection element driver,
8. Deflection element

Claims (12)

In the light irradiation device that scans and irradiates the light beam,
A light source that modulates and outputs beam light according to irradiation data;
A deflection element for two-dimensionally scanning the light beam of the light source;
A first data holding unit for holding irradiation data generated corresponding to the operation of the deflection element at a first timing;
A second data holding unit that holds irradiation data held in the first data holding unit at a second timing for driving the light source;
The first timing is an equal time interval,
The second timing is an unequal time interval, and is determined by a beam irradiation position corresponding to the operation of the deflection element. In the light irradiation apparatus of Claim 1,
The first data holding unit is a shift register;
The light irradiation apparatus, wherein the second data holding unit is a latch register. In the light irradiation apparatus in any one of Claim 1 or Claim 2,
A counter for determining a predetermined count value and managing the second timing;
The counter is reset at the start timing of one line of scanning or the start timing of one screen. A data generation unit that generates light beam information to be irradiated in synchronization with the deflection element control unit;
A data conversion unit that converts the data generated and transmitted by the data generation unit to correspond to a plurality of light source drivers and light sources;
A light source driver corresponding to each light source for driving at least two light sources based on the data converted by the data conversion unit;
An optical element group for making light generated by the light source into a light beam and guiding the light to a deflection element;
A deflection element control unit that synchronizes the data generation unit and generates a reference signal for operating the deflection element;
A deflection element driver for driving the deflection element based on the reference signal generated by the deflection element control unit;
The data generation unit generates latch signals at unequal intervals, generates irradiation data to be emitted from the light source at the same time in synchronization with the latch signals, and the data conversion unit at the timing of the latch signals A light irradiation apparatus that transfers irradiation data to the light source driver to drive a light source. In the light irradiation apparatus of Claim 4,
The data conversion unit sequentially transfers irradiation data generated in the data generation unit by a shift register in synchronization with a transfer clock, and further holds and outputs data by a latch register by a latch signal. Irradiation device. In the light irradiation device,
A data generation unit that generates light beam information to be irradiated in synchronization with the deflection element control unit;
A data timing correction unit that corrects the data generated and transmitted by the data generation unit to a desired data timing;
A data conversion unit for converting to correspond to a plurality of light source drivers and light sources;
A light source driver corresponding to each light source for driving at least two light sources based on the data converted by the data conversion unit;
An optical element group for making light generated by the light source into a light beam and guiding the light to a deflection element;
A deflection element control unit that synchronizes the data generation unit and generates a reference signal for operating the deflection element;
Based on the reference signal generated by the deflection element control unit, having a pre-deflection element driver for driving the deflection element,
The data generation unit generates latch signals at equal intervals, generates irradiation reference data to be emitted from the light source at the same time in synchronization with the latch signals, and the data timing correction unit generates non-uniform intervals. An equal interval latch signal is generated, and irradiation data is generated in synchronization with the non-equal interval latch signal based on the irradiation reference data. In the data conversion unit, the irradiation data is sent to the light source driver at the timing of the latch signal. A light irradiation device that transfers and drives a light source. In the light irradiation apparatus of Claim 6,
The data conversion unit sequentially transfers irradiation data generated in the data generation unit by a shift register in synchronization with a transfer clock, and further holds and outputs data by a latch register by a latch signal. Irradiation device. In the light irradiation apparatus in any one of Claim 6 or Claim 7,
The data timing correction unit receives the input data based on the input latch signal, an internal decoding unit that decodes the received input data, a counter that counts by a transfer clock, and the counter value as an input to obtain and set the reference data timing in advance. A light irradiation apparatus comprising: a latch signal generation unit that generates a latch signal, and a data encoding unit that generates a data signal in synchronization with the latch signal. In the light irradiation device,
A data generation unit that generates light beam information to be irradiated in synchronization with the deflection element control unit;
A data conversion unit that converts the data generated and transmitted by the data generation unit to correspond to a plurality of light source drivers and light sources;
A light source driver corresponding to each light source for driving at least two light sources based on the data converted by the data conversion unit;
An optical element group for making light generated by the light source into a light beam and guiding the light to a deflection element;
A deflection element control unit that synchronizes the data generation unit and generates a reference signal for operating the deflection element;
The deflection element driver for driving the deflection element according to a resonance condition based on the reference signal generated by the deflection element control unit;
The data generation unit includes an address counter that counts in accordance with the operation of the polarization element, a sine wave conversion unit that converts the counter value of the address counter into sine wave-like data, and the sine wave converted by the sine wave conversion unit. Based on the wave data, a distortion correction unit that corrects distortion due to the shape of the projection surface, a scaling unit that converts the distortion correction data generated by the distortion correction unit into image address data having a desired number of image data, An image data generation unit that generates reference data based on the image address data,
The data generation unit generates latch signals at unequal intervals, generates irradiation data to be emitted from the light source at the same time in synchronization with the latch signals, and the data conversion unit at the timing of the latch signals A light irradiation apparatus that transfers irradiation data to the light source driver to drive a light source. In the light irradiation apparatus of Claim 9,
The data converter sequentially transfers the irradiation data generated in the data generator in synchronization with the transfer clock by the shift register. Further, the light irradiating apparatus characterized in that data is held and output by a latch register according to a latch signal. In the light irradiation apparatus in any one of Claim 9 or Claim 10,
The data timing correction unit includes an address correction unit that provides an address difference corresponding to a light beam angle correction amount of a plurality of light sources, following the scaling unit. In the light irradiation apparatus in any one of Claim 9 to 11,
A light irradiation apparatus characterized in that image data is up-converted with a resolution of at least twice that of an original image when converted to an image data address by the scaling unit.

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