JP6295900B2 - Image drawing apparatus and image drawing method - Google Patents

Description

  The present invention relates to an image drawing apparatus and an image drawing method.

  As this type of technology, Patent Document 1 discloses a laser projector that displays a desired image on a screen by two-dimensionally scanning laser light output from a semiconductor laser. In general, the I-L characteristic, which is the relationship between the drive current of a laser light source such as a semiconductor laser and the amount of output light, easily changes due to temperature fluctuations of the laser light source itself. Therefore, in Patent Document 1, an error in the output value due to temperature fluctuation of the laser light source itself is suppressed by appropriately adjusting the drive current of the laser light source while the laser light is shielded by the shielding plate.

JP 2013-164503 A

  By the way, the applicant of the present application outputs laser light (hereinafter, characteristic detection laser light) for detecting the output value of the laser light from the laser light source at an arbitrary timing, and measures the output light quantity of the laser light with a photodiode. As a result, APC technology (Auto Power Control) has been developed that acquires the actual light intensity for a predetermined drive current and adjusts the drive current of the laser light source based on the acquired light intensity. In the APC technique, the direction in which the adjustment laser beam is irradiated is the same as in Patent Document 1 so that the characteristic detection laser beam does not reach the range in which the drawn image is presented to the user such as a screen. Shielding is performed using a shielding plate or the like.

  Here, the image drawing area and the blanking area will be described. The aforementioned two-dimensional scanning area (hereinafter referred to as scanning area) is divided into an image drawing area and a blanking area. The image drawing area is an area for emitting laser light based on the drawn image data in order to draw an image to be displayed on the screen, and is generally rectangular. The blanking area is an area that does not emit laser light for drawing an image around the image drawing area.

  When the above APC is executed, even if the characteristic detection laser light is irradiated, the characteristic detection laser light does not directly affect the image drawn in the image drawing area because it is shielded by the shielding plate or the like. However, stray light due to irregular reflection of the characteristic detection laser beam may be reflected in the image drawing area. For this reason, the quality of the image drawn in the image drawing area is lowered.

  An object of the present invention is to provide an image drawing apparatus and an image drawing method that suppress a reduction in drawing quality of a drawn image due to laser light irradiation for detecting an output value of laser light.

  Accordingly, the present invention provides a laser light source unit that outputs laser light, a scanner unit that reflects and scans the laser light output from the laser light source unit, and input image data within a scanning area scanned by the scanner unit. The laser light output timing of the laser light source unit and the output value of the laser light are controlled so that a drawn image based on the scanning is generated by the scanner unit, and the output value of the laser light output by the laser light source unit is detected A laser light source control unit that controls the laser light source unit to output characteristic detection laser light for scanning, and a scanner control unit that controls scanning of the scanner unit so that the scanner unit scans the laser light with a predetermined amplitude. And when the output value of the laser beam output from the laser light source unit is adjusted, the amplitude of scanning of the scanner unit is larger than the predetermined amplitude. The characteristic detection laser is controlled by controlling the scanner control unit so as to be scanned, and controlling the laser light source control unit so as to output the characteristic detection laser beam outside the region where the drawing image is generated. There is provided an image drawing apparatus including a characteristic detection control unit that adjusts an output value of a laser beam based on a detection result of an output value of light.

  Further, the present invention is an image drawing method for generating a drawn image by reflecting a laser beam output from a laser light source unit to a scanner unit that scans with a predetermined amplitude, and outputting the laser beam output from the laser light source unit When adjusting the value, a characteristic detection laser for detecting the output value of the laser beam outside the region where the drawing image is generated by scanning the scanning amplitude of the scanner unit with an amplitude larger than the predetermined amplitude Provided is an image drawing method for outputting light and adjusting an output value of a laser beam based on a detection result of an output value of the characteristic detection laser beam.

  ADVANTAGE OF THE INVENTION According to this invention, the drawing quality fall of the drawing image by irradiation of the laser beam for detecting the output value of a laser beam can be suppressed.

It is a functional block diagram of an image drawing apparatus. (First embodiment) It is a figure which shows the example of input image data. (First embodiment) It is a figure which shows the example of laser drive data typically. (First embodiment) It is a graph which shows typically a time change of a vertical scanning angle and a horizontal scanning angle. (First embodiment) It is a figure which shows the locus | trajectory of scanning typically. (First embodiment) It is a flowchart which shows the example of control of an image drawing apparatus. (First embodiment) It is a graph which shows typically a time change of a vertical scanning angle and a horizontal scanning angle. (First embodiment) It is a figure which shows the example of laser drive data typically. (First embodiment) It is a figure which shows the locus | trajectory of scanning typically. (First embodiment) It is a graph which shows typically a time change of a vertical scanning angle and a horizontal scanning angle. (Second Embodiment) It is a figure which shows the example of laser drive data typically. (Second Embodiment) It is a figure which shows the locus | trajectory of scanning typically. (Second Embodiment)

(First embodiment)
The first embodiment will be described below with reference to the drawings. FIG. 1 shows a functional block diagram of the image drawing apparatus 1 of the first embodiment. The image drawing device 1 is specifically a head-up display device, which is mainly mounted on a vehicle and presents various information as virtual images to a driver who is a user. When the image drawing device 1 is used as a head-up display device, an image intended for route guidance, an image intended for warning, an image based on content reproduction, and an image related to various UIs (User Interfaces) Are presented as virtual images based on the drawn images. These images may be still images or moving images.

  The image drawing apparatus 1 includes a control unit 2, a laser light source unit 3, a scanner unit 4, a DDR memory 5 (Double Data Rate), and a shielding plate 9 as a shielding unit.

  The control unit 2 includes a central processing unit (CPU) (not shown), a read / write free RAM (Random Access Memory), a read-only ROM (Read Only Memory), and the like. Then, when the CPU reads and executes the image drawing program stored in the ROM, the image drawing program uses the hardware such as the CPU as the laser light source control unit 6, the scanner control unit 7, and the characteristic detection control unit 8. Make it work.

  The laser light source unit 3 includes a laser module 10 that outputs laser light, and a laser driver 11 that drives a laser diode 101 provided in the laser module 10. In this embodiment, the laser module 10 includes a red laser diode 101R, a green laser diode 101G, a blue laser diode 101B, a dichroic mirror 102 corresponding to each laser diode 101, and a photodiode 14. The laser beams of the respective colors output from the laser diodes 101 included in the laser module 10 are combined by the dichroic mirror 102 and output to the scanner unit 4. The laser driver 11 drives the laser diode 101 included in the laser module 10 based on the laser drive signal from the control unit 2.

  The dichroic mirror 102R has a characteristic of reflecting almost 100% of the red wavelength light output from the red laser diode 101R. The dichroic mirror 102G has a characteristic of transmitting approximately 100% of the red wavelength light output from the red laser diode 101R and reflecting approximately 100% of the green wavelength light output from the green laser diode 101G. The dichroic mirror 102B has a characteristic of reflecting about 98% and transmitting about 2% of the red wavelength light output from the red laser diode 101R and the green wavelength light output from the green laser diode 101G. Further, the dichroic mirror 102B has a characteristic of transmitting about 98% of the blue wavelength light output from the blue laser diode 101B and reflecting about 2%.

  With the configuration of the dichroic mirror 102 as described above, approximately 98% of the laser light output from each laser diode 101 is reflected by the scanner unit 12 and approximately 2% of the laser light is incident on the photodiode 14. . The photodiode 14 measures the light amount of each laser beam incident as a light amount measuring unit, and outputs the measurement result to the control unit 2. The arrangement of the laser diode 101 and the dichroic mirror 102 is not limited to the arrangement shown in FIG. 1, and the same output may be provided to the scanner unit 4 and the photodiode 14.

  The scanner unit 4 includes a scanner 12 that reflects and scans the laser light output from the laser light source unit 3, a scanner driver 13 that drives the scanner 12, and scanning as a scanning angle detection unit that detects the scanning angle of the scanner 12. And a corner detection unit 15. The scanner 12 includes a vertical mirror 12a that scans laser light in the vertical direction (first scanning direction) and a horizontal mirror 12b that scans laser light in the horizontal direction (second scanning direction). Both the vertical mirror 12a and the horizontal mirror 12b are constituted by MEMS (micro electro mechanical system) mirrors. The scanner driver 13 drives the scanner 12 based on the scanner drive signal from the control unit 2. The scanning angle detector 15 detects the scanning angles of the vertical mirror 12 a and the horizontal mirror 12 b and outputs the detection result to the controller 2.

  When the scanner 12 is composed of a vertical mirror 12a and a horizontal mirror 12b, the vertical mirror 12a operates at a scanning angle and an oscillation frequency that are generally controlled by the scanner driver 13. Since the horizontal mirror 12b has a high oscillation frequency, the horizontal mirror 12b generally operates at a scanning angle and an oscillation frequency due to resonance. However, the horizontal mirror 12b also has a scanning angle and oscillation controlled by the scanner driver 13 like the vertical mirror 12a. It may be configured to operate at a frequency.

  Based on the input image data input to the control unit 2, a laser beam output from the laser light source unit 3 is scanned by the scanner unit 4, thereby generating a drawn image. In the example of FIG. 1, the laser beam scanned by the scanner unit 4 is projected on the screen 16. The screen 16 is generally an intermediate image screen when the image drawing device 1 is used as a head-up display device. Although the structure of the head-up display is not shown, the drawn image projected on the intermediate image screen is projected on a combiner or a windshield of an automobile through reflection by a concave mirror or the like.

  The DDR memory 5 is a frame buffer that temporarily stores input image data input to the control unit 2.

  The shielding plate 9 is a plate that shields laser light. The laser beam shielded by the shielding plate 9 does not reach the projection direction beyond the screen 16. The shielding plate 9 has a shape that shields the characteristic detection laser light without shielding the laser light in the range where the drawn image is drawn out of the laser light reflected by the scanner unit 4. The shielding plate 9 is formed using a housing of the image drawing apparatus 1 or a housing of a unit including the scanner unit 4 and the laser light source unit 3. Further, when the scanner unit 4 is installed as a module in the image drawing apparatus 1, the shielding plate 9 is installed at a position where laser light is emitted from the module, or from the housing of the image drawing apparatus 1 to the screen 16. The position where the laser beam is emitted may be at the front portion or the rear portion of the screen 16.

  The laser light source control unit 6 is a functional unit that controls the output of the laser diode 10 by outputting a laser drive signal to the laser driver 11. The laser light source controller 6 has a laser drive signal frame buffer 6a. The laser light source control unit 6 reads input image data for one frame from the DDR memory 5, and stores the read input image data as it is in the laser drive signal frame buffer 6a as laser drive data. FIG. 2 shows a drawing image example for one frame of input image data. For convenience of explanation, it is assumed that the pixel size of the input image data is n rows and m columns, and the image of the input image data has a red circle drawn at the center. FIG. 3 shows laser drive data. The laser drive data is configured to generate an image of one frame having a pixel size of n rows and m columns in synchronization with the scanning of the scanner unit 4. As shown in FIGS. 2 and 3, the laser drive data is usually exactly the same data as the input image data. The laser light source controller 6 sequentially outputs the laser drive data stored in the laser drive signal frame buffer 6a to the laser driver 11 as a laser drive signal according to the dot clock. Therefore, the laser light source control unit 6 controls the output timing of the laser light so that a drawn image based on the input image data is generated by scanning of the scanner unit 4 within the scanning range scanned by the scanner unit 4. Further, the laser light source control unit 6 controls driving of the red, blue, and green laser diodes so as to obtain appropriate output values according to the color and luminance of the drawn image based on the input image data.

  The scanner control unit 7 is a functional unit that controls scanning of laser light by the scanner 12 by outputting a scanner drive signal to the scanner driver 13. FIG. 4 shows an example of the vertical scanning angle a of the vertical mirror 12a and the horizontal scanning angle b of the horizontal mirror 12b. As shown in FIG. 4, the vertical scanning angle a is represented by a triangular wave, and the horizontal scanning angle b is represented by a sine wave. The amplitude and scanning center of the vertical scanning angle a are constant, and the amplitude and scanning center of the horizontal scanning angle b are also constant. The scanning frequency of the vertical mirror 12a is 60 Hz, for example. The scanning frequency of the horizontal mirror 12b is higher than the scanning frequency of the vertical mirror 12a, for example, 15 kHz. In this specification, for convenience of explanation, the scanning frequency of the horizontal mirror 12b is set to 12 times the scanning frequency of the vertical mirror 12a. FIG. 5 shows a state in which the image drawing apparatus 1 draws an image on the screen 16 based on the input image data. In FIG. 5, a thin solid line indicates the locus of the scanning position of the scanner 12. As shown in FIG. 5, the locus of the scanning position of the scanner 12 is within a rectangular frame. An area within the rectangular frame is referred to as a scanning area SA. The horizontal width SAH of the scanning area SA corresponds to the amplitude HA of the horizontal scanning angle b in FIG. Similarly, the vertical width SAV of the scanning area SA in FIG. 5 corresponds to the amplitude VA of the vertical scanning angle a in FIG. The scanning area SA is divided into an image drawing area DA and a blanking area BA. The image drawing area DA is an area inside the scanning area SA, and is a rectangular area where an image is actually drawn. The blanking area BA is an area of a rectangular frame surrounding the image drawing area DA, and is an area where a laser beam for drawing a drawn image is not output. The blanking area BA further includes an upper blanking area BAU, a lower blanking area BAD, a left blanking area BAL, and a right blanking area BAR. The upper blanking area BAU is an area above the image drawing area DA in the blanking area BA. The horizontal width of the upper blanking area BAU is equal to the horizontal width SAH. The lower blanking area BAD is an area below the image drawing area DA in the blanking area BA. The horizontal width of the lower blanking area BAD is equal to the horizontal width SAH. The left blanking area BAL is an area on the left side of the image drawing area DA in the blanking area BA. The vertical width of the left blanking area BAL is equal to the vertical width SAV. The right blanking area BAR is an area on the right side of the image drawing area DA in the blanking area BA. The vertical width of the right blanking area BAR is equal to the vertical width SAV. The upper blanking area BAU partially overlaps the left blanking area BAL and the right blanking area BAR. The lower blanking area BAD partially overlaps the left blanking area BAL and the right blanking area BAR. Hereinafter, the scanning of the scanner 12 will be described in detail with reference to FIGS. 4 and 5.

  As shown in FIG. 4, in the vertical scanning, the upper blanking area scanning period P1 in which the scanning position moves downward in the upper blanking area BAU in order on the time axis, and the scanning position is the upper blanking area BAU and the lower blanking. Image drawing area scanning period P2 that moves downward between areas BAD, lower blanking area scanning period P3 in which the scanning position moves downward in the lower blanking area BAD, vertical return in which the scanning position moves upward in the scanning area SA This is achieved by repeating the scanning period P4. The image of the input image data is drawn on the screen 16 in the image drawing area scanning period P2, and in the period of the lower blanking area scanning period P3, the vertical return scanning period P4, and the upper blanking area scanning period P1 which are continuous on the time axis. Nothing is drawn on the screen 16. Hereinafter, the image drawing area scanning period P2 is referred to as an image drawing period Q1 as a period for drawing an image. A period constituted by the lower blanking area scanning period P3, the vertical return scanning period P4, and the upper blanking area scanning period P1 that are continuous on the time axis is referred to as a non-image drawing period Q2 as a period during which no image is drawn. Accordingly, the vertical scanning is realized by repeating the image drawing period Q1 and the non-image drawing period Q2 on the time axis. A period constituted by one vertical return scanning period P4, one upper blanking area scanning period P1, one image drawing area scanning period P2, and one lower blanking area scanning period P3 which are continuous on the time axis. This is called a frame period F as a period for one frame. Therefore, vertical scanning is realized by repeating the frame period F on the time axis.

  The vertical scanning angle a at the scanning center of the vertical scanning is defined as the vertical scanning angle center a0, the vertical scanning angle a at the time of folding up the vertical scanning is set as the folding up scanning angle a1, and the vertical scanning angle at the folding down of the vertical scanning Let a be the downward folding scanning angle a2. Similarly, the horizontal scanning angle b at the scanning center of the horizontal scanning is set as the horizontal scanning angle center b0, the horizontal scanning angle b at the right side of the horizontal scanning is set as the right folding scanning angle b1, and the horizontal at the left side of the horizontal scanning is turned up. The scanning angle b is referred to as a left folded scanning angle b2.

  The characteristic detection control unit 8 is a functional unit that periodically detects whether an appropriate output light amount is obtained with respect to a predetermined drive current applied to the laser diode 101. For example, the laser diode 101 may not be able to obtain a light amount based on the rated value of the I-L characteristic due to a decrease in ambient temperature. In this case, the color tone of the generated drawn image changes due to different characteristics of the red, blue, and green laser diodes 101. In FIG. 1, the characteristic detection control unit 8 outputs the characteristic detection laser beam to each of the red, blue, and green laser diodes 101 constituting the laser diode 101, and measures the light amount of the characteristic detection laser beam from the photodiode 14. Based on the measurement result, the drive current of the laser driver 11 is controlled so that each laser diode 101 outputs an appropriate amount of light. Such processing is hereinafter referred to as APC (Auto Power Control) processing. The characteristic detection laser beam is a test laser beam for detecting the output value of the laser beam output from each laser diode 101. The characteristic detection control unit 8 optimizes the control of the laser driver 11 by the laser light source control unit 6 by feeding back the detected output value to the laser light source control unit 6. The frequency with which the characteristic detection control unit 8 executes the APC process is, for example, about once per 120 frames.

  In addition, when performing the APC process, the characteristic detection control unit 8 scans the scanner 12 so that the scanning amplitude of the scanner 12 is scanned with an amplitude (second amplitude) that is larger than a predetermined amplitude (first amplitude). The controller 7 is controlled. The predetermined amplitude is the amplitude VA in the case of the vertical mirror 12a, and the amplitude HA in the case of the horizontal mirror 12b. It is appropriate to execute the APC process by the characteristic detection processing unit 8 during a period of one frame of the drawn image. Furthermore, when performing the APC process, the characteristic detection control unit 8 controls the laser light source control unit 6 so that the characteristic detection laser light is output outside the region where the drawn image is generated.

  Hereinafter, for convenience of description, the frame period F in which the APC process is performed by the characteristic detection control unit 8 among the plurality of frame periods F is specifically referred to as a characteristic detection frame period FIL, and the frame periods F other than the characteristic detection frame period FIL are usually This is called a frame period FD.

  Hereinafter, the APC processing by the characteristic detection control unit 8 among the operations of the image drawing apparatus 1 will be described in detail.

  FIG. 6 shows a control flow of the image drawing apparatus 1, and FIG. 7 shows a graph showing temporal changes in the vertical scanning angle and the horizontal scanning angle. Here, as shown in FIG. 7, the first frame period F and the third frame period F appearing on the time axis are normal frame periods FD, and the second frame period F is a characteristic detection frame period. Suppose that it is FIL.

  The characteristic detection control unit 8 first determines whether the next frame period F is the characteristic detection frame period FIL (S100). When it is determined that the next frame period F is not the characteristic detection frame period FIL (S100: NO), the characteristic detection control unit 8 repeats the above determination because the next frame period F is the normal frame period FD. When it is determined that the next frame period F is the characteristic detection frame period FIL (S100: YES), the characteristic detection control unit 8 enlarges the scanner 12 in the characteristic detection frame period FIL as shown in FIG. The scanner controller 7 is instructed to scan with the amplitude (S110). In the present embodiment, the scanner control unit 7 expands the vertical scanning amplitude in the characteristic detection frame period FIL. As shown in FIG. 7, the scanner control unit 7 performs the characteristic detection frame period FIL so that the vertical scanning amplitude VAIL in the characteristic detection frame period FIL is larger than the vertical scanning amplitude VA in the normal frame period FD. Magnify the vertical scanning amplitude at. On the other hand, the scanner control unit 7 keeps the horizontal scanning in the characteristic detection frame period FIL as the horizontal scanning in the normal frame period FD.

  Next, the characteristic detection control unit 8 instructs the laser light source control unit 6 to generate laser drive data used in the characteristic detection frame period FIL (S115). Specifically, the laser light source control unit 6 performs the laser in the characteristic detection frame period FIL based on the ratio between the vertical scanning amplitude VA in the normal frame period FD and the vertical scanning amplitude VAIL in the characteristic detection frame period FIL. Generate drive data. FIG. 8 shows an example of laser drive data in the characteristic detection frame period FIL. When the amplitude VAIL is set to 1.2 times the amplitude VA, the laser light source control unit 6 reduces the image of FIG. 2 to 83% in the vertical direction, so that the laser in the characteristic detection frame period FIL is obtained. Generate drive data. As a result, as shown in FIG. 9, the size of the drawn image drawn in the characteristic detection frame period FIL is equal to the size of the drawn image drawn in the normal frame period FD (see FIG. 5). Is less likely to occur.

  Next, the characteristic detection control unit 8 instructs the laser light source control unit 6 to output the characteristic detection laser light from the laser module 10 in the characteristic detection frame period FIL (S120). FIG. 7 shows the timing at which the characteristic detection laser beam is output. The characteristic detection laser light is output from each of the red, blue, and green laser diodes 101 for each characteristic detection frame, and the photodiode 14 measures the output light amount of each laser diode 101. In FIG. 9, the area where the characteristic detection laser beam is projected is indicated by a thick line so as to overlap the trajectory of scanning. As shown in FIGS. 7 and 9, the laser light source control unit 6 performs laser scanning while the scanner 12 is scanning outside the scanning area SA (hereinafter simply referred to as the scanning area SA) in the normal frame period FD. The output of each laser diode 101 is controlled so that the characteristic detection laser beam is output from the module 10. The shielding plate 9 shown in FIG. 1 is disposed at a position that shields the characteristic detection laser beam output from the laser module 10 while the scanner 12 scans the outside of the scanning area SA. According to the above processing, the position where the characteristic detection laser beam is projected can be further separated in the vertical direction from the position of the drawing image, with almost no change in the shape of the drawing image. For this reason, it is possible to reduce the stray light caused by the irregular reflection of the characteristic detection laser light shielded by the shielding plate 9 from being reflected in the drawn image area DA, and to suppress the deterioration of the quality of the drawn image.

  Next, the characteristic detection control unit 8 acquires a measurement result from the photodiode 14 that measures the amount of the characteristic detection laser light (S130), and based on the acquired measurement result, an actual output value of each laser diode 101. (S140), and the laser light source controller 6 is controlled so that each laser diode 101 outputs an appropriate amount of light based on the detection result.

  Although the first embodiment has been described above, the first embodiment can be modified as follows.

  For example, the timing for outputting the characteristic detection laser beam may be any timing as long as the scanner 12 is scanning the outside of the scanning area SA. For example, the timing may be within the vertical return scanning period P4, or within the upper blanking area scanning period P1, the image drawing area scanning period P2, and the lower blanking area scanning period P3.

(Second Embodiment)
Next, a second embodiment will be described. Hereinafter, the present embodiment will be described with a focus on differences from the first embodiment, and overlapping description will be omitted.

  In the first embodiment, the characteristic detection control unit 8 increases the amplitude of vertical scanning in the characteristic detection frame period FIL. In contrast, in the present embodiment, as shown in FIGS. 10 and 12, the horizontal scanning amplitude is expanded in the characteristic detection frame period FIL.

  That is, the characteristic detection control unit 8 first determines whether the next frame period F is the characteristic detection frame period FIL (S100). When it is determined that the next frame period F is not the characteristic detection frame period FIL (S100: NO), the characteristic detection control unit 8 repeats the above determination because the next frame period F is the normal frame period FD. When it is determined that the next frame period F is the characteristic detection frame period FIL (S100: YES), the characteristic detection control unit 8 enlarges the scanner 12 in the characteristic detection frame period FIL as shown in FIG. The scanner controller 7 is instructed to scan with the amplitude (S110). As shown in FIG. 10, the scanner control unit 7 performs the characteristic detection frame period FIL so that the horizontal scanning amplitude HAIL in the characteristic detection frame period FIL is larger than the horizontal scanning amplitude HA in the normal frame period FD. While expanding the horizontal scanning amplitude in, the scanner control unit 7 keeps the vertical scanning in the characteristic detection frame period FIL as vertical scanning in the normal frame period FD.

  Next, the characteristic detection control unit 8 instructs the laser light source control unit 6 to generate laser drive data used in the characteristic detection frame period FIL (S115). Specifically, the laser light source control unit 6 performs the laser in the characteristic detection frame period FIL based on the ratio of the horizontal scanning amplitude HA in the normal frame period FD and the horizontal scanning amplitude HAIL in the characteristic detection frame period FIL. Generate drive data. FIG. 11 shows laser drive data in the characteristic detection frame period FIL. When the amplitude HAIL is set to 1.2 times the amplitude HA, the laser light source control unit 6 reduces the image of FIG. 2 to be 83% in the horizontal direction, so that the laser in the characteristic detection frame period FIL is obtained. Generate drive data. As a result, as shown in FIG. 12, the size of the drawn image drawn in the characteristic detection frame period FIL is equal to the size of the drawn image drawn in the normal frame period FD (see FIG. 5). Is less likely to occur.

  Next, the characteristic detection control unit 8 instructs the laser light source control unit 6 to output the characteristic detection laser light from the laser module 10 in the characteristic detection frame period FIL (S120). FIG. 10 shows the timing at which the characteristic detection laser beam is output. The characteristic detection laser light is output from each of the red, blue, and green laser diodes 101 for each characteristic detection frame, and the photodiode 14 measures the output light amount of each laser diode 101. In FIG. 12, the area where the characteristic detection laser beam is projected is indicated by a thick line so as to overlap the scanning locus. As shown in FIG. 10 and FIG. 12, the laser light source controller 6 is configured so that each laser diode outputs a characteristic detection laser beam from the laser module 10 while the scanner 12 scans outside the scanning area SA. 101 is controlled. The shielding plate 9 shown in FIG. 1 is disposed at a position that shields the characteristic detection laser beam output from the laser module 10 while the scanner 12 scans the outside of the scanning area SA. According to the above processing, the position at which the characteristic detection laser beam is projected can be further separated in the horizontal direction from the position of the drawing image with almost no change in the shape of the drawing image. For this reason, it can reduce that the stray light by the irregular reflection of the characteristic detection laser beam shielded by the shielding plate 9 is reflected in the drawn image region, and can suppress the deterioration of the quality of the drawn image.

  Next, the characteristic detection control unit 8 acquires a measurement result from the photodiode 14 that measures the amount of the characteristic detection laser light (S130), and based on the acquired measurement result, an actual output value of each laser diode 101. (S140), and the laser light source controller 6 is controlled so that each laser diode 101 outputs an appropriate amount of light based on the detection result.

  Although the second embodiment has been described above, the second embodiment can be modified as follows.

  For example, the timing for outputting the characteristic detection laser beam may be any timing as long as the scanner 12 is scanning the outside of the scanning area SA. For example, the timing may be within the vertical return scanning period P4, or within the upper blanking area scanning period P1, the image drawing area scanning period P2, and the lower blanking area scanning period P3.

  Although the first embodiment and the second embodiment have been described above, each of the above embodiments has the following features.

(1) The image drawing apparatus 1 includes a laser light source unit 3 that outputs a laser beam, a scanner unit 4 that reflects and scans the laser beam output from the laser light source unit 3, and a scanning area that the scanner unit 4 scans. The laser light output timing of the laser light source unit 3 and the output value of the laser light are controlled so that a drawn image based on the input image data is generated by scanning of the scanner unit 4, and the laser light output from the laser light source unit 3 is controlled. A laser light source control unit 6 that controls the laser light source unit 3 to output characteristic detection laser light for detecting an output value, and the scanner unit 4 scans the laser light with a predetermined amplitude VA (or amplitude HA). When adjusting the output value of the laser beam output from the scanner control unit 7 that controls the scanning of the scanner unit 4 and the laser light source unit 3, the amplitude of the vertical scanning (or horizontal scanning) of the scanner unit 4 is a predetermined amplitude. The laser light source control unit 6 controls the scanner control unit 7 so that scanning is performed with an amplitude larger than the width (VA or HA), and outputs the characteristic detection laser light outside the region where the drawn image is generated. And a characteristic detection control unit 8 that adjusts the output value of the laser beam based on the detection result of the output value of the laser beam by the characteristic detection laser beam. According to the above configuration, it is possible to suppress a reduction in drawing quality of a drawn image due to irradiation with a characteristic detection laser beam output during APC processing.

(2) In addition, the characteristic detection control 8 is configured so that when the scanner unit 4 is scanned with the enlarged amplitude, the size of the drawn image is constant based on the ratio between the predetermined amplitude and the enlarged amplitude. The light source controller 6 is controlled.

  Each said embodiment can be changed as follows, for example.

  The drawing data in the characteristic detection frame period FIL may be a single color tone based on the average color tone of the input image data and a single brightness level based on the average luminance of the input image data.

  As described above, the reason why the single-tone image based on the average tone of the input image data and the single-luminance image based on the average luminance of the input image data is inserted into the characteristic detection frame period FIL is the predetermined amplitude and the expanded amplitude. This is because even a drawn image drawn so that the size of the drawn image is constant based on the ratio of When such a drawn image is inserted into one frame among a plurality of consecutive frames, a sense of incongruity may be felt.

  The characteristic detection control unit 8 generates a single color tone based on the average color tone of the input image data and a single luminance image based on the average luminance of the input image data based on the input image data. The characteristic detection generation unit 8 calculates the average tone and the average luminance from the color information and the luminance information for all the pixels of the drawn image constituting one frame for the drawing data in the frame period immediately before the characteristic detection frame period FIL. A drawing image having the calculated average color tone and average luminance is generated.

  By such processing, it is possible to suppress a sense of incongruity occurring before and after the APC processing by the characteristic detection control unit 8 with simple control.

DESCRIPTION OF SYMBOLS 1 Image drawing apparatus 6 Laser light source control part 7 Scanner control part 8 Characteristic detection control part 9 Shielding plate 10 Laser module 12 Scanner 14 Photodiode

Claims (4)

A laser light source for outputting laser light;
A scanner unit that reflects and scans the laser beam output from the laser light source unit;
The laser light output timing of the laser light source unit and the output value of the laser light are controlled so that a drawn image based on input image data is generated by scanning of the scanner unit in a scanning region scanned by the scanner unit, A laser light source control unit for performing control to output a characteristic detection laser beam for detecting an output value of the laser beam output from the laser light source unit to the laser light source unit;
A scanner control unit that controls scanning of the scanner unit so that the scanner unit scans the laser beam with a predetermined amplitude;
When adjusting the output value of the laser beam output from the laser light source unit, the scanner control unit is controlled so that the scanning amplitude of the scanner unit is scanned with an amplitude larger than the predetermined amplitude, The laser light source control unit is controlled to output the characteristic detection laser light outside the region where the drawing image is generated, and the output value of the laser light is determined based on the detection result of the output value of the characteristic detection laser light. A characteristic detection control unit to be adjusted;
Bei to give a,
When the scanner unit is scanned with an enlarged amplitude, the characteristic detection control unit is configured to make the size of the drawn image constant based on a ratio between the predetermined amplitude and the enlarged amplitude. Control the light source controller,
Image drawing device. A laser light source for outputting laser light;
A scanner unit that reflects and scans the laser beam output from the laser light source unit;
The laser light output timing of the laser light source unit and the output value of the laser light are controlled so that a drawn image based on input image data is generated by scanning of the scanner unit in a scanning region scanned by the scanner unit, A laser light source control unit for performing control to output a characteristic detection laser beam for detecting an output value of the laser beam output from the laser light source unit to the laser light source unit;
A scanner control unit that controls scanning of the scanner unit so that the scanner unit scans the laser beam with a predetermined amplitude;
When adjusting the output value of the laser beam output from the laser light source unit, the scanner control unit is controlled so that the scanning amplitude of the scanner unit is scanned with an amplitude larger than the predetermined amplitude, The laser light source control unit is controlled to output the characteristic detection laser light outside the region where the drawing image is generated, and the output value of the laser light is determined based on the detection result of the output value of the characteristic detection laser light. A characteristic detection control unit to be adjusted;
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When the scanner unit is scanned with an enlarged amplitude, the characteristic detection control unit replaces a drawn image based on the input image data with a single color tone based on an average color tone of the input image data, and the input image Controlling the laser light source controller so that a drawing image based on single-luminance image data based on the average luminance of the data is generated;
Image drawing device. An image drawing method for generating a drawing image by reflecting a laser beam output from a laser light source unit to a scanner unit that scans with a predetermined amplitude,
When adjusting the output value of the laser beam output from the laser light source unit, the scanning amplitude of the scanner unit is scanned with an amplitude that is larger than the predetermined amplitude,
Output a characteristic detection laser beam for detecting an output value of the laser beam outside the region where the drawing image is generated,
When the scanner unit is scanned with an enlarged amplitude, based on the ratio between the predetermined amplitude and the enlarged amplitude, the laser beam is output so that the size of the drawn image is constant,
Adjusting the output value of the laser beam based on the detection result of the output value of the characteristic detection laser beam;
Image drawing method. An image drawing method for generating a drawing image based on input image data by reflecting a laser beam output from a laser light source unit to a scanner unit that scans with a predetermined amplitude,
When adjusting the output value of the laser beam output from the laser light source unit, the scanning amplitude of the scanner unit is scanned with an amplitude that is larger than the predetermined amplitude,
Output a characteristic detection laser beam for detecting an output value of the laser beam outside the region where the drawing image is generated,
When the scanner unit is scanned with an enlarged amplitude, instead of a drawing image based on the input image data, a single color tone based on an average color tone of the input image data and a single color tone based on an average luminance of the input image data Outputting the laser beam so that a drawing image based on the image data of luminance is generated;
Adjusting the output value of the laser beam based on the detection result of the output value of the characteristic detection laser beam;
Image drawing method.

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