JP2017072827A - Projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection device capable of reducing or preventing problems caused by emission delays of light sources.SOLUTION: A projection device includes a plurality of light sources that emit laser light, a scanning unit that scans the laser light, and a controller that controls laser light output. The controller provides control such that, within a scanning range including a first scanning range and a second scanning range, the laser light output is a first light quantity in the first scanning range and is a second light quantity greater than the first light intensity in the second scanning range.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a projection apparatus.

  In an optical projection apparatus that forms an image on a projection surface by optical projection, light of a desired color is projected using a plurality of types of semiconductor laser elements such as red, green, and blue. However, even when a drive current is applied to the semiconductor laser element, a certain time is required until a carrier having a concentration capable of laser oscillation is generated. For this reason, there is a case where a light emission delay occurs and a rise time is required until light of a light amount corresponding to the drive current is output. Note that the light emission delay means that only a low amount of light is output from the semiconductor laser element at the beginning of the application of the drive current, and the time until a constant amount of light corresponding to the current value of the applied drive current is output. This is the phenomenon. Particularly, in recent years, a system using a 600 [nm] red semiconductor laser element and a 500 [nm] green semiconductor laser element has been put into practical use. In these semiconductor laser elements, the rise time is likely to occur as compared with the conventional semiconductor laser elements in the 1.3 μm band, 1.5 μm band, or 780 nm band. This is because these semiconductor laser elements have characteristics that require more time until carriers having a concentration capable of laser oscillation are generated.

  For this reason, in Patent Document 1, for example, the light emission delay of the semiconductor laser element is compensated by adding an auxiliary current to the drive current at the start of light emission.

JP 2012-209380 A

  However, in an optical projection apparatus including a plurality of semiconductor laser elements, the degree of rise time varies depending on the type of semiconductor laser element. For this reason, when a light emission delay of a different level occurs in each semiconductor laser element, the timing at which the amount of light corresponding to the drive current is output from each semiconductor laser element shifts, and the edge portion of the image displayed on the projection surface is colored. Unevenness occurs. For example, among a plurality of types of semiconductor laser elements, red and green semiconductor laser elements tend to cause a light emission delay. Therefore, when projecting a white image by simultaneously emitting light from each semiconductor laser element, there is no light emission delay in the blue semiconductor laser element, resulting in uneven color in the projected light, especially the edge portion of the image is bluish It becomes a color.

  With respect to such a problem, Patent Document 1 makes no mention of compensating for the light emission delay of a plurality of types of semiconductor laser elements having different degrees. Further, in Patent Document 1, since the auxiliary current is added to the drive current at the start of light emission, the amount of light easily overshoots, and it is difficult to adjust the light amount at the start of light emission. Furthermore, there is a problem that the power consumption for the auxiliary current increases.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a projection device that can suppress or prevent the occurrence of a problem due to light emission delay of a light source.

  In order to achieve the above object, a projection apparatus according to an aspect of the present invention includes a plurality of light sources that emit laser light, a scanning unit that scans the laser light, and a control unit that controls the output of the laser light. And the control unit performs control so that the output becomes the first light amount in the first scanning range in a scanning range including the first scanning range and the second scanning range, and the output in the second scanning range. Is a configuration (first configuration) in which control is performed so that the second light amount is larger than the first light amount.

  The projection apparatus having the first configuration includes a memory that stores image information of an image to be projected onto a projection plane, and the control unit controls the output of the laser light based on the image information (second configuration). Configuration).

  In the projection device having the first or second configuration, the control unit is configured such that the time from when the laser beam starts to be emitted until the output reaches the first light amount starts to decrease from the first light amount. Based on the fact that it is shorter than the time until the laser beam emission stops, in the scanning range, the output is controlled to be the first light quantity in the first scanning range, and the output is the first scanning range in the second scanning range. A configuration in which the control is performed to obtain a second light amount larger than the light amount (third configuration) may be employed.

  In the projection apparatus having any one of the first to third configurations, the scanning unit scans the laser light in a reciprocating manner, and determines an emission start position and an emission stop position of the laser light in the first scanning range of the forward path. The laser beam emission stop position and emission start position in the first scanning range of the return path may be configured (fourth configuration).

  In the projection device having the fourth configuration, the second scanning range of the forward path is scanned with the laser beam in the backward path from the start of emission in the backward path until the output reaches the first light amount. A configuration (fifth configuration) that overlaps the third scanning range may be used.

  The projection apparatus having the fifth configuration may have a configuration (sixth configuration) in which a scanning distance in the second scanning range of the forward path is equal to or less than a scanning distance in the third scanning range of the return path. Good.

  In the projection device having any one of the fourth to sixth configurations, the control unit reduces the accumulated light amount in the second scanning range of the forward path and the return path due to an emission delay of the light source. It may be configured to perform control so as to be the same as (seventh configuration).

  The projection apparatus having any one of the first to seventh configurations further includes a light source driving unit that supplies a driving current to the light source, the light source is a semiconductor laser element, and the light source driving unit is configured to stop emission. When the amount of the laser beam is suddenly reduced, the second current less than the oscillation threshold current from the first current value equal to or higher than the oscillation threshold current indicating the lower limit of the current value emitted by the semiconductor laser element only in the laser oscillation mode. A configuration (eighth configuration) in which the drive current is decreased to a current value may be employed.

  In the projection device having any one of the first to eighth configurations, the control unit is configured to increase the second light amount in the second scanning range in a plurality of stages (a ninth configuration). May be.

  In the projection apparatus having any one of the first to ninth configurations, the light source is a semiconductor laser element, and the semiconductor laser element is in a laser oscillation mode in a predetermined period until the emission start in the first scanning range. It may be a configuration (tenth configuration) in which a current less than a current value emitted by only the semiconductor laser element is applied to the semiconductor laser element.

  In the projection apparatus of the tenth configuration, the current supply time is longer than the time required for the semiconductor laser element to reach the first light output from the start of emission (the eleventh configuration). ).

  In the projection apparatus having the first configuration, the plurality of light sources include a first light source and a second light source, and the time required for the first light source to output a predetermined light amount is longer than that of the second light source. The control unit may be configured to perform control to supply a drive current to the first light source before the second light source (a twelfth configuration).

  In the projection device having the twelfth configuration, the control unit performs control such that the amount of light of the first light source and the amount of light of the second light source are the same at each time point when the light amount reaches a predetermined amount. Configuration).

  In the projection device of the twelfth configuration, the control unit is configured to control the first light source based on a time difference of each time from the start of emission of the laser light until the output reaches the first light amount in the plurality of light sources. And a configuration (14th configuration) in which control is performed so that the time points at which the light amount of the second light source and the light amount of the second light source reach the predetermined ratio with respect to the predetermined light amount are the same.

  In the projection device having any one of the twelfth to fourteenth configurations, the control unit supplies the second light source with a driving current having a first current value that causes the light output to be less than the predetermined light amount, and then performs the predetermined operation. A configuration (a fifteenth configuration) may be provided in which a drive current having a second current value for causing a light output of a certain amount of light is supplied to the second light source.

  In the projection device having any one of the twelfth to fifteenth configurations, the control unit increases the driving current of the second light source in a plurality of stages up to a current value for outputting the predetermined amount of light. (16th structure) may be sufficient.

  The projection device having any one of the twelfth to sixteenth configurations calculates the time of each of the plurality of light sources based on a detection result of a light detection unit that detects the amount of light of each of the plurality of light sources. A configuration (a seventeenth configuration) may further be included.

  The projection device of the seventeenth configuration may have a configuration (eighteenth configuration) in which the control unit performs control to emit the laser light from a plurality of the light sources when scanning the invalid projection area. .

  In the projection device of the eighteenth configuration, when the control unit scans the invalid projection area, the calculation unit calculates the time based on a detection result of the light detection unit when scanning the invalid projection area. The configuration to be determined (19th configuration) may be used.

  In the projection apparatus having any one of the twelfth to nineteenth configurations, the predetermined light amount may be a light amount necessary for emitting white light (a twentieth configuration).

  ADVANTAGE OF THE INVENTION According to this invention, the projection apparatus which can suppress or prevent generation | occurrence | production of the problem resulting from the light emission delay of a light source can be provided. For example, when a plurality of light emitting elements perform light output, it is possible to improve light color unevenness caused by a difference in light emission delay for each light emitting element. In addition, it is possible to improve the decrease in the amount of light caused by the light emission delay at the start of light emission of the light emitting element.

It is the schematic of a HUD apparatus. It is a block diagram which shows the structural example of a projector unit. It is a graph which shows the optical output characteristic with respect to the drive current of LD. It is a graph which shows the response characteristic of the optical output of red LD. It is a graph which shows the response characteristic of the light output of green LD. It is a graph which shows the response characteristic of the light output of blue LD. It is a figure which shows the scanning condition of a scanning laser beam on the projection surface of a combiner. It is a flowchart for demonstrating an example of the light output control process of LD which concerns on 1st Embodiment. It is a schematic diagram which shows the light output of the scanning laser beam in case all LD outputs a light simultaneously. It is a graph which shows an example of light output control of LD concerning a 1st embodiment. It is a schematic diagram which shows an example of the optical output of the scanning laser beam in the case of performing optical output control which concerns on 1st Embodiment. It is a graph which shows an example of light output control of LD concerning a 2nd embodiment. It is a graph which shows an example of light output control of LD concerning a 3rd embodiment. It is a graph which shows another example of light output control of LD concerning a 3rd embodiment. It is a schematic diagram which shows locally the scanning range of the scanning light scanned back and forth continuously. It is a graph which shows an example of the light output control of red LD in 4th Embodiment. It is a figure which shows the light output change of the scanning light of the going path scanned from a 1st scanning position to a 2nd scanning position in 4th Embodiment. It is a figure which shows the light output change of the scanning light of the return path | route scanned from a 2nd scanning position to a 1st scanning position in 4th Embodiment. It is a figure which shows the light quantity change of the apparent scanning light between the 1st scanning position and 2nd scanning position in 4th Embodiment. It is a flowchart for demonstrating an example of the optical output control process of LD which concerns on 4th Embodiment. It is a figure which shows the ideal light output change of LD in the case of performing the light output of a steady light quantity, and the actual light output change in the scanning laser beam of an outward path and a return path | route. It is a figure which shows the ideal light output change of LD in the case of raising light output gently in the starting scanning range in the 1st scanning position side, and the actual light output change in an outward path and a return path. It is a figure which shows the ideal light output change of LD in the case of raising light output gently in the start-up scanning range at the 2nd scanning position side, and the actual light output change in an outward path and a return path. It is a graph which shows an example of the light output control of red LD in 5th Embodiment. It is a figure which shows the light output change of the outward scanning light scanned from a 1st scanning position to a 2nd scanning position in 5th Embodiment. It is a figure which shows the light output change of the scanning light of the return path | route scanned from a 2nd scanning position to a 1st scanning position in 5th Embodiment. It is a figure which shows the change in the apparent light quantity of the scanning light between the 1st scanning position and 2nd scanning position in 5th Embodiment. It is a graph which shows an example of the light output control of green LD in 6th Embodiment. It is a figure which shows the light output change of the outward scanning light scanned from the 1st scanning position to the 2nd scanning position in 6th Embodiment. It is a figure which shows the light output change of the scanning light of the return path | route scanned from a 2nd scanning position to a 1st scanning position in 6th Embodiment. It is a figure which shows the light quantity change of the apparent scanning light between the 1st scanning position and 2nd scanning position in 6th Embodiment. It is a graph which shows the optical output characteristic with respect to the drive current of red LD. It is a graph which shows an example of light output control of red LD in a 7th embodiment. It is a figure which shows the light output change of the scanning light of the going path scanned from a 1st scanning position to a 2nd scanning position in 7th Embodiment. It is a figure which shows the light output change of the scanning light of the return path | route scanned from a 2nd scanning position to a 1st scanning position in 7th Embodiment. It is a figure which shows the light quantity change of the apparent scanning light between the 1st scanning position and 2nd scanning position in 7th Embodiment. It is a flowchart for demonstrating an example of the optical output control process of LD which concerns on 7th Embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings, using a vehicle head-up display device 100 as an example. Hereinafter, the head-up display device 100 is referred to as a HUD (Head-Up Display) device 100.

<First Embodiment>
FIG. 1 is a schematic diagram of the HUD device 100. The HUD device 100 of this embodiment is mounted on a vehicle 200. The HUD device 100 is a display device that projects the scanning laser light 300 (scanning light) from the projector unit 101 (light projection device) toward the combiner 102 and displays the projected image in a user's field of view. In FIG. 1, an alternate long and short dash line arrow 400 indicates the line of sight of the user sitting in the driver's seat of the vehicle 200. The HUD device 100 is not limited to a vehicle, and may be mounted on another vehicle (for example, an aircraft).

  As shown in FIG. 1, the combiner 102 is attached to the inner surface of the windshield 201 of the vehicle 200. The combiner 102 is a projection member for displaying the projection image of the projector unit 101 within the user's field of view, and is formed using a semi-transmissive reflective material such as a half mirror. By projecting the scanning laser light 300 from the projector unit 101 onto the combiner 102, a virtual image (video) is formed in a predetermined area of the projection surface 102a of the combiner 102. For this reason, the user who is looking in front of the vehicle 200 (that is, in the direction of the line of sight 400) can view the external image in front of the vehicle 200 and the projection image projected from the projector unit 101 at the same time.

  Next, the projector unit 101 will be described. FIG. 2 is a block diagram illustrating a configuration example of the projector unit 101. As shown in FIG. 2, in the first embodiment, the projector unit 101 includes a housing 1, an optical engine unit 2, and a MEMS engine unit 3.

  The housing 1 is equipped with an optical engine unit 2 and a MEMS engine unit 3. Further, the housing 1 is formed with a window portion 1a (light transmission window) for emitting the scanning laser light 300 emitted from the MEMS engine portion 3 to the outside. The window part 1a is formed using glass or a translucent resin material, for example. A more detailed configuration of the housing 1 will be described later.

  The optical engine unit 2 includes a plurality of laser diodes 21 a to 21 c, an optical system 22, and photodetectors 23 a to 23 c, and emits light to the MEMS engine unit 3. In the following description, the laser diodes 21a to 21c are referred to as LDs (Laser Diodes) 21a to 21c, respectively, and the photodetectors 23a to 23c are referred to as PDs (Photo Detectors) 23a to 23c, respectively. In addition, the structure of the optical engine part 2 is not limited to the illustration of FIG. For example, the optical engine unit 2 replaces the photodetectors 23a to 23c with a half mirror (for example, a transmittance of 99%) disposed between the optical system 22 and the MEMS engine unit 3, and the light output of the reflected light of the half mirror. A PD (light detection unit) for detecting the light may be included.

  The LD 21a is a light emitting element that emits red laser light. The LD 21b is a light emitting element that emits green laser light. The LD 21c is a light emitting element that emits blue laser light.

  Here, the light output characteristics with respect to the drive current of the LDs 11a to 11c will be described. Here, the LD 11a is described as an example, but the optical output characteristics with respect to the drive currents of the other LDs 11b and 11c are also the same, and therefore the description thereof is omitted. FIG. 3 is a graph showing optical output characteristics with respect to the drive current of the LD 11a. When the light output of the LD 11a and the drive current applied to the LD 11a are within the rectangular range Ag colored in FIG. 3, the LD 11a emits light in a state where the laser oscillation mode and the LED emission mode are mixed. Therefore, the light output of the LD 11a becomes unstable. The points GA and GB on the graph are the lower limit and the upper limit of the graph within the range Ag, respectively. When the light output and the drive current become less than the light output PA corresponding to the lower limit point GA and the current value IA, the LD 11a emits light in the LED light emission mode. In this case, the LD 11a outputs emitted light whose wavelength and phase are more irregular than in the laser oscillation mode, but emits light more stably than light emission within the range Ag. Further, when the light output and the drive current become larger than the light output PB and the current value IB corresponding to the upper limit point GB, the LD 11a emits light in the LD oscillation mode. In this case, the LD 11a outputs coherent light having a relatively uniform wavelength and phase by a stable laser oscillation operation.

  Next, the optical response characteristics of the LDs 11a to 11c will be described. 4A to 4C are graphs showing the response characteristics of the optical outputs of the LDs 21a to 21c to which the constant drive currents Ia1 to Ic1 are applied. FIG. 4A is a graph showing the response characteristics of the light output of the red LD 21a. FIG. 4B is a graph showing the response characteristics of the light output of the green LD 21b. FIG. 4C is a graph showing the response characteristics of the light output of the blue LD 21c. 4A to 4C, time tS indicates the time when application of the drive current starts (that is, light emission starts), and time tE indicates the time when application of the drive current ends (that is, when light emission ends). These are the same in other figures.

  As shown in FIGS. 4A to 4C, the response characteristics of the light outputs of the LDs 21a to 21c are different. For example, each of the LDs 21a to 21c has a light emission delay at the start of application of the drive current. The light emission delay means that only a low amount of light is output at the start of application of the drive current to each of the LDs 21a to 21c, and the steady light amounts Pa1, Pb1, and Pc1 corresponding to the applied drive current values Ia1, Ib1, and Ic1. This is a phenomenon in which rise times TA, TB, and TC are required until light is output. The rise times TA, TB, and TC are optical response times from the start of light emission (start of application of drive current) to the light output Pa1, Pb1, and Pc1 corresponding to the current values Ia1, Ib1, and Ic1 of the drive current. The time lengths of the LDs 21a to 21c are different. The response characteristics of the light output of the LDs 21a to 21c when the white display is performed from the state where the LDs 21a to 21c have the light amount 0 (that is, the state where the light output is 0) will be described below.

  In the red LD 21a, as shown in FIG. 4A, when a constant drive current Ia1 is applied at time ta0 (= tS), the rise time TA (until the light is emitted with a steady light amount Pa1 corresponding to the drive current Ia1. = Ta1-ta0). That is, the light output of the red LD 21a gradually increases from time ta0, becomes half PaPa of the steady light amount at time ta2, and becomes steady light amount Pa1 at time ta1. The steady light amount Pa1 is, for example, the light amount Pa1 of the LD 21a when the LD 21a to 21c performs white display. As described above, the red LD 21a is a light emitting element having the longest rise time TA required to output light having a constant light amount Pa1 from a state where the light amount is 0 among the LDs 21a to 21c.

  In the green LD 21b, as shown in FIG. 4B, when a constant drive current Ib1 is applied at time tb0 (= tS), the rise time until light is emitted with a steady light amount Pb1 corresponding to the drive current Ib1. TB (= tb1-tb0) is required. That is, the light output of the green LD 21a increases from time tb0, becomes half PB1 of the steady light quantity at time tb2, and becomes steady light quantity Pb1 at time tb1. The steady light amount Pb1 is, for example, the light amount Pb1 of the LD 21b when the LD 21a to 21c performs white display. However, the rising time TB of the green LD 21b is earlier than the rising time TA of the red LD 21a (0 <TB <TA).

  On the other hand, in the blue LD 21c, the response characteristic of the light output is very good as shown in FIG. 4C, and when the constant drive current Ic1 is applied at time tc0 (= tS), it immediately corresponds to the drive current Ic1. It emits light with a steady light quantity Pc1. That is, the blue LD 21c requires almost no rise time TC (TC≈0). The steady light amount Pc1 is, for example, the light amount Pc1 of the LD 21c when the LD 21a to 21c performs white display.

  Next, returning to FIG. 2, the optical engine unit 2 will be described. The optical system 12 includes collimator lenses 221a to 221c, beam splitters 222a to 222c, and a condenser lens 223. The collimator lenses 221a to 221c are optical elements that convert the laser beams emitted from the LDs 21a to 21c into parallel beams. The beam splitters 222a to 222c are optical elements such as dichroic mirrors, for example, which reflect light of a specific wavelength and transmit light of other wavelengths. Further, the beam splitters 222a to 222c respectively reflect part of the light incident from the collimator lenses 221a to 221c and transmit the remaining part. Each of the PDs 23a to 23c is a light detection unit that detects a light output of light incident from the beam splitters 222a to 222c, and outputs a light detection signal based on the detection result to the CPU 58 described later.

  The red laser light emitted from the LD 21a is converted into parallel light by the collimator lens 221a. Part of the red laser light is reflected by the beam splitter 222a, passes through the beam splitter 222c, and reaches the condenser lens 223. The remaining part of the red laser light passes through the beam splitter 222a and enters the PD 23a. Further, the green laser light emitted from the LD 21b is converted into parallel light by the collimator lens 221b. Part of the green laser light is reflected by the beam splitter 222b, passes through the beam splitters 222a and 222c, and reaches the condenser lens 223. The remaining part of the green laser light passes through the beam splitter 222b and enters the PD 23b. Further, the blue laser light emitted from the LD 21c is converted into parallel light by the collimator lens 221c. Part of the blue laser light is reflected by the beam splitter 222 c and reaches the condenser lens 223. The remaining part of the blue laser light passes through the beam splitter 222c and enters the PD 23c. The condensing lens 223 converges each laser beam incident from each of the LDs 21 a to 21 c via the collimator lenses 221 a to 221 c and the beam splitters 222 a to 222 c on the light reflecting surface of the MEMS mirror 31.

  The MEMS engine unit 3 includes a MEMS mirror 31, and scans the projection surface 102a by swinging and driving the scanning laser light 300 projected from the LD 21a to 21c onto the projection surface 102a of the combiner 102 and its optical axis. This is a scanning optical unit. The MEMS mirror 31 is an optical reflection element that reflects the laser beam converged by the condenser lens 223. The MEMS mirror 31 reflects each laser beam as a scanning laser beam 300. The scanning laser light 300 passes through a window portion 1 a of the housing 1 and a light emission port 50 a described later, is emitted to the outside of the projector unit 101, and is projected onto a projection surface 102 a on the combiner 102. Further, the MEMS mirror 31 scans the scanning laser light 300 on the projection surface 102a by swinging in the biaxial direction and changing the optical axis of the scanning laser light 300. As described above, the MEMS mirror 31 scans the scanning laser light 300 projected onto the projection surface 102 a by driving the optical axis of the scanning laser light 300 to swing in the horizontal direction and the vertical direction of the combiner 102.

  FIG. 5 is a diagram showing a scanning situation of the scanning laser light 300 on the projection surface 102a of the combiner 102 and its optical axis. Hereinafter, in the projection surface 102a, the horizontal direction toward the right side of the projection surface 102a may be referred to as the X direction, and the vertical direction toward the lower side of the projection surface 102a may be referred to as the Y direction. These are the same in other figures.

  The scanning laser beam 300 is reciprocally scanned in the horizontal direction X with the direction range in the vertical direction Y as shown in FIG. 5, for example, by the swing drive of the MEMS mirror 31 on the projection surface 102 a. That is, the optical axis of the scanning laser beam 300 alternately performs zigzag reciprocating scanning in the Y direction and zigzag reciprocating scanning in the −Y direction. In the following, zigzag reciprocal scanning in the Y direction from the uppermost side to the lowermost side in FIG. 5 is referred to as a trace. Further, the zigzag reciprocal scanning in the −Y direction from the lowermost side to the uppermost side in FIG. 5 is referred to as retrace.

  In the trace, an image is formed on the projection surface 102a by a group of scanning laser beams 300 having a direction range in the vertical direction Y and reciprocally scanned in the horizontal direction X. That is, this image is formed by a group of scanning laser beams 300 in which scanning in the −X direction having a predetermined Y direction component and scanning in the X direction having a predetermined Y direction component are alternately performed. Hereinafter, the scanning laser beam 300 having a predetermined Y-direction component and scanned in the −X direction is referred to as a forward scanning laser beam 300a. The scanning laser beam 300 having a predetermined Y direction component and scanned in the X direction is referred to as a backward scanning laser beam 300b. The predetermined Y direction component of each scanning laser beam 300a, 300b is determined according to the scanning pitch (that is, scanning interval) in the Y direction of each scanning laser beam 300a, 300b.

  In FIG. 5, the area surrounded by the alternate long and short dash line in the projection surface 102a is the effective projection area 102b. An area other than the projection area 102b is an invalid projection area 102c. The effective projection area 102b is an area in which an image by the scanning laser beam 300 can be formed during the trace period. Note that no video is formed during the retrace period. The invalid projection area 102c is an area in which no video is formed during the trace period and the retrace period. In this region 102c, the optical axis of the scanning laser beam 300 is scanned, but the scanning laser beam 300 itself for forming an image is not projected.

  Next, returning to FIG. 2, a further configuration of the projector unit 101 will be described. The projector unit 101 further includes a main body casing 50, a MEMS mirror driver 51, an LD driver 52, a power source 53, a power control unit 54, an operation unit 55, an input / output I / F 56, a storage unit 57, CPU58.

  The main body housing 50 includes a housing 1, a MEMS mirror driver 51, an LD driver 52, a power supply 53, a power supply control unit 54, an operation unit 55, an input / output I / F 56, a storage unit 57, and a CPU 58. In addition, the main body casing 50 is formed with a light emission port 50a. The scanning laser light 300 that has passed through the window portion 1a of the housing 1 from the MEMS engine portion 3 is further emitted to the combiner 102 through the light emission port 50a. The light exit 50a may be an opening, but is preferably formed using, for example, glass or a translucent resin material. By so doing, it is possible to prevent intrusion of dust and moisture (for example, water droplets or air containing water) into the inside of the main body housing 50.

  The MEMS mirror driver 51 is a drive control unit that controls the driving of the MEMS mirror 31 based on a control signal input from the CPU 58. For example, the MEMS mirror driver 51 swings and drives the MEMS mirror 31 according to the horizontal synchronization signal from the CPU 58, and deflects the reflection direction of the laser light by the MEMS mirror 31 in the horizontal direction of the projection surface 102a. The MEMS mirror driver 51 swings and drives the MEMS mirror 31 according to the vertical synchronization signal from the CPU 58, and deflects the reflection direction of the laser light by the MEMS mirror 31 in the vertical direction of the projection surface 102a.

  The LD driver 52 is a light source drive unit that supplies a drive current to each of the LDs 21a to 21c, and performs drive control such as light emission and light output of each of the LDs 21a to 21c. The LD driver 52 is a part of the light output control unit, for example, supplies a drive current equal to or greater than the oscillation threshold current value (for example, the current value IB of the right 3) to the LDs 21a to 21c to output laser light. The power source 53 is a power supply unit that receives power from a power source such as a storage battery (not shown) of the vehicle 200, for example. The power supply control unit 54 converts the power supplied from the power supply 53 into a predetermined voltage value and current value corresponding to each component of the projector unit 101, and supplies the converted power to each component. The operation unit 55 is an input unit that receives a user operation input. The input / output I / F 56 is a communication interface for wired communication or wireless communication with an external device.

  The storage unit 57 is a non-volatile storage medium, and stores, for example, a program and control information used by each component of the projector unit 101. The storage unit 57 also stores video information to be projected onto the combiner 102, operating characteristics of the LDs 21a to 21c, information on light amount correction (for example, response characteristics of light output described later), and the like.

  The CPU 58 is a control unit that controls each component of the projector unit 101 using a program and control information stored in the storage unit 57. As shown in FIG. 2, the CPU 58 includes a video processing unit 581, a light output control unit 582, and a calculation unit 583. The CPU 58 is a part of the light output control unit.

  The video processing unit 581 generates video information based on a program stored in the storage unit 57, information input from the input / output I / F 56, information stored in the storage unit 57, and the like. Further, the video processing unit 581 converts the generated video information into video data of three colors of red (R), green (G), and blue (B). The converted three-color video data is output to the light output control unit 582.

  The light output control unit 582 performs light output control of the LDs 21a to 21c. For example, the light output control unit 582 captures video data output from the video processing unit 581 (that is, video information of a video formed on the projection surface 102a) in a memory (not shown) and performs image analysis. That is, color information, luminance information, and the like of an image formed on the projection surface 102a are analyzed. Further, the light output control unit 582 controls the light output of the plurality of LDs 21a to 21c based on the analysis result and information on the operating characteristics of the LDs 21a to 21c. For example, the light output control unit 582 generates a light control signal for each of the LDs 21 a to 21 c based on the image analysis result of the three colors of video data, and outputs the light control signal to the LD driver 52. Each laser beam emitted from each LD 21 a to 21 c based on each light control signal is two-dimensionally scanned by driving the MEMS mirror 31, so that a video (projected image) based on video information is displayed on the windshield 201. It is projected on the combiner 102.

  The calculation unit 583 performs various calculations based on the response characteristics of the light outputs of the LDs 21a to 21c. For example, the calculation unit 583 calculates the rise times TA, TB, and TC of the LDs 21a to 21c based on the detection results of the PDs 23a to 23c. Then, the calculation unit 583 uses the rising times TA, TB, and TC to calculate the times (light emission start times) ta0, tb0, and tc0 and the time differences between the driving currents Ia1, Ib1, and Ic1 applied to the LDs 21a to 21c. calculate.

  Next, the light output control processing of the LDs 21a to 21c will be described. FIG. 6 is a flowchart for explaining an example of the light output control processing of the LDs 21a to 21c according to the first embodiment. The following S101 to S106 are performed during the retrace period, and S107 is performed during the trace period. The light output control process illustrated in FIG. 6 is also applied to second and third embodiments described later.

  First, when the optical axis of the scanning laser beam 300 scans the invalid projection area 102c in the retrace period, the light output control unit 582 applies predetermined drive currents Ia1 to Ic1 to the LDs 21a to 21c for a predetermined time. That is, the light output control unit 582 causes each of the LDs 21a to 21c to perform light output of a predetermined light amount (for example, Pa1, Pb1, Pc1) (S101). The application times of the drive currents Ia1 to Ic1 may be longer than the rise times TA, TB, and TC of the LDs 21a to 21c, respectively. And PD23a-23c detects the optical output of each LD21a-21c (S102). The calculation unit 583 calculates the rise times TA, TB, and TC of the LDs 21a to 21c based on the detection results of the PDs 23a to 23c (S103). Then, the calculation unit 583 calculates time differences TB1 (= TA−TB) and TC1 (= TA−TC≈TA) between the longest rising time TA and other rising times TB and TC (S104). Further, the calculation unit 583 obtains the light emission start times tb0 and tc0 of the LDs 21b and 21c based on the time differences TB1 and TC1 (S105). The light output control unit 582 loads the video data output from the video processing unit 581 into a memory (not shown), and performs image analysis of the video projected on the projection surface 102a during the trace period based on the video data (S106). ). That is, the color information and luminance information of the video formed during the trace period are analyzed.

  Next, in the trace period, the light output control unit 582 performs light output control of the LDs 21a to 21c based on the result of image analysis, the calculation result of the calculation unit 583, information stored in the storage unit 57, and the like ( S106).

  In the light output control process described above, S104 may be performed after the light output control unit 582 identifies the LD having the longest rise time. In this case, the time difference between the specified LD and another LD is obtained. Usually, the rise time TA of the red LD 21a is the longest, but the rise times Tb and TC of the LDs 21a to 21c may change due to the state of the element (temperature conversion, deterioration, etc.). Accordingly, if the light output control unit 582 functions as an element specifying unit that specifies the LD having the longest rise time as described above, even if the rise time TB of the LD 21b or the rise time TC of the LD 21c is the longest. The light output control unit 582 can perform similar light output control. That is, the light output control can be performed so that the times ta1, tb1, and tc1 at which the LDs 21a to 21c become the steady light amounts Pa1, Pb1, and Pc1, respectively, are the same time.

  Next, the light output control of the LDs 21a to 21c in the case where the white display is performed from the state where the light amount is 0 (that is, the state where the light output is 0) will be described in detail with reference to comparative examples and examples.

<Comparative example>
First, a comparative example will be described. As described above, the rising times TA, TB, and TC at the start of light emission differ depending on the LDs 21a to 21c (see FIGS. 4A to 4C). Therefore, when the LDs 21a to 21c simultaneously output light, clear color unevenness occurs in a predetermined period from the light emission start time tS. FIG. 7 is a schematic diagram illustrating the light output of the scanning laser light 300 when all the LDs 21a to 21c perform light output simultaneously. In FIG. 7, positions LS, Lb, La, and LE indicate the center position of the light spot 300 c of the scanning laser beam 300 in the scanning direction of the scanning laser beam 300. The position LS is the center position of the light spot 300c at the light emission start time tS of the LDs 21a to 21c. The position Lb is the center position of the light spot 300c at the time tb1 of the LD 21b. The position La is the center position of the light spot 300c at the time ta1 of the LD 21a. The position LE is the center position of the light spot 300c at the light emission stop time tE of the LDs 21a to 21c. These are the same in FIG. 9 described later.

  As shown in FIG. 7, the scanning laser light 300 projected onto the projection surface 102a has clear color unevenness between the positions LS to La. The position LS to La corresponds to the period TA from the light emission start time tS of each of the LDs 21a to 21c to the time ta1 after the rising time TA of the red LD 21a. That is, at the position LS at the light emission start time tS, the scanning laser light 300 has almost only a blue component. Between the position LS and the position Lb, the red component and the green component of the scanning laser light 300 gradually increase, but the blue component is a steady light amount Pc1. At the position Lb, the green component becomes a steady light amount Pb1 corresponding to the drive current Ib1, but the red component light amount of the scanning laser light 300 is still small and less than the steady light amount Pa1. Then, the red component of the scanning laser light 300 increases from the position Lb to the position La, and the red component becomes a steady light amount Pa1 corresponding to the drive current Ia1 at the position La.

<Example>
Next, examples will be described. FIG. 8 is a graph showing an example of light output control of the LDs 21a to 21c according to the first embodiment. FIG. 9 is a schematic diagram showing an example of the light output of the scanning laser light 300 when performing light output control according to the first embodiment.

  As shown in FIG. 8, in this embodiment, when images are formed by the light outputs of the LDs 21a to 21c, the LDs 21a to 21c have steady light amounts Pa1, Pb1, and Pc1 corresponding to the drive currents Ia1, Ib1, and Ic1, respectively. The drive currents Ia1, Ib1, and Ic1 are applied to the LDs 21a to 21c so that the times ta1, tb1, and tc1 (≈tc0) are the same time. That is, the light output control unit 582 starts applying the drive current to the LD 21a having the longest rise time TA among the LDs 21a to 21c based on the time differences between the rise times TA, TB, and TC of the LDs 21a to 21c. The time point ta0 is set earlier than the time points tb0 and tc0 at which application of the drive current to the other LDs 21b and 21c is started. Further, the light output control unit 582 applies a time ta0 from the other LD 21b, 21c when the drive current Ia1 for outputting the light of the steady light amount Pa1 from the LD 21a is applied to the LD 21a based on the time difference between the rising times TA, TB, TC. The drive currents Ib1 and Ic1 for outputting the light of the steady light amounts Pb1 and Pc1 are applied earlier than the time points tb0 and tc0, respectively, when they are applied to the LDs 21b and 21c, respectively. The light output control unit 582 sets the time ta1 when the light amount of the LD 21a reaches the steady light amount Pa1 and the time points tb1 and tc1 when the light amounts of the LD 21b and 21c reach the steady light amounts Pb1 and Pc1, respectively.

  In this case, the time point ta0 is set to the light output control start time tS. The driving current Ib1 is applied to the green LD 21b at a time tb0 after the time difference TB1 (= TA−TB) from the light emission start time ta0 (that is, the time tS) of the red LD 21a, and the green LD 21b starts to emit light. The blue LD 21c is started to emit light when the drive current Ic1 is applied at a time point tc1 (= ta1) after the time difference TC1 (= TA) from the light emission start time tS.

  In this way, as shown in FIG. 9, the color unevenness generated in the scanning laser light 300 at the positions LS to La is greatly reduced as compared with the case where each of the LD 21a to LD 21c emits light simultaneously (see FIG. 7). That is, since the scanning laser beam 300 has a small red component between the position LS and the position Lb immediately after the light emission start time tS, the color unevenness is not conspicuous. At the position Lb, the green LD 21b starts to emit light, but the red and green components of the scanning laser light 300 are still small. And between the position Lb and the position La, the red component and the green component of the scanning laser beam 300 increase. At the position La, the blue LD 21c starts to emit light, and the red component, the green component, and the blue component become steady light amounts Pa1, Pb1, and Pc1 corresponding to the drive currents Ia1, Ib1, and Ic1 applied to the LDs 21a to 21c. .

Second Embodiment
Next, a second embodiment will be described. In the second embodiment, the light output control is performed so that the times ta2, tb2, and tc2 (≈tc0) at which the LDs 21a to 21c become half the steady light amounts 0.5Pa1, 0.5Pb1, and 0.5Pc1 are the same time. The unit 582 performs light output control of the LDs 21a to 21c. The rest is the same as in the first embodiment. Hereinafter, a configuration different from the first embodiment will be described. Moreover, the same code | symbol is attached | subjected to the component similar to 1st Embodiment, and the description is abbreviate | omitted.

  FIG. 10 is a graph illustrating an example of light output control of the LDs 21a to 21c according to the second embodiment. FIG. 10 shows the response characteristics of the light outputs of the LDs 21a to 21c when, for example, the LDs 21a to 21c perform white display from the state where the light quantity is zero. As shown in FIG. 10, the time ta0 when the drive current Ia1 for outputting the light of the steady light amount Pa1 from the LD 21a is applied to the LD 21a is half of the rise time (TA / 2), (TB / 2), (TC / 2). ) Is earlier than the time points tb0 and tc0 when the drive currents Ib1 and Ic1 for outputting the light of the regular light amounts Pb1 and Pc1 from the other LDs 21b and 21c are applied to the LDs 21b and 21c, respectively.

  As shown in FIG. 10, the drive currents Ia1, Ib1, and Ic1 are applied to the LDs 21a to 21c so that the times ta2, tb2, and tc2 are the same time. That is, the light output control unit 582 determines the time ta2 when the LD 21a reaches half of the steady light amount 0.5Pa1 based on the time difference between the rising times TA, TB, and TC of the LDs 21a to 21c, and the LD 21b has the steady light amount. The time point tb2 reaching half 0.5Pb1 and the time point tc2 (= tc0) are made the same. In other words, the light output control unit 582, based on the time difference between the rise times TA and TB of the LDs 21a to 21c, the time point ta2 at which the light amount of the LD 21a reaches 50% of the steady light amount Pa1, and the LD 21b The time tb2 when the light quantity reaches a ratio of 50% with respect to the steady light quantity Pb1 is made the same. Since the LD 21c has almost no rise time TC, the time tc2 when half of the steady light quantity of the LD 21c reaches 0.5Pc1 (that is, the time when the ratio to the steady light quantity Pc1 reaches 50%) is the same as the time tc0. Can be considered.

  In this case, first, the light emission start time ta0 of the LD 21a having the longest rise time is set as the light output control start time tS. Then, the drive current Ia1 is applied to the red LD 21a to start light emission. The drive current Ib1 is applied to the green LD 21b at time tb0 after time TB2 (= (TA−TB) / 2) from the light emission start time ta0 of the red LD 21a, and light emission of the green LD 21b is started. The blue LD 21c requires almost no rise time TC (that is, TC≈0). Therefore, the drive current Ic1 is applied to the blue LD 21c at time ta2 after the time TC2 (= TA / 2) from the light emission start time tS, and light emission of the blue LD 21c is started.

  In the present embodiment, an example in which the times ta2, tb2, and tc2 are set at the same time has been described, but the present invention is not limited to this example. Times tb2 and tc2 may be later than time ta2 and earlier than time ta1. That is, based on the time difference between the rising times TA, TB, and TC, the time when the light amount of the LD 21a reaches a predetermined ratio with respect to the first light amount Pa1, and the light amounts of the LD 21b and 21c are the above for the first light amount Pb1 and Pc1, respectively. The time when the predetermined ratio is reached may be the same.

  Even in this case, the color unevenness generated in the scanning laser light 300 in the period TA from the light emission start time ta0 to the time ta1 of the LD 21a is much larger than that in the case where each of the LD 21a to LD 21c emits light simultaneously (see FIG. 7). Can be reduced.

<Third Embodiment>
Next, a third embodiment will be described. In the third embodiment, the color unevenness generated in the scanning laser light 300 is reduced by gradually increasing the drive currents Ib1 and Ic1 applied to the green LD 21b and the blue LD 21c other than the red LD 21a having the longest rise time TA. The rest is the same as in the first embodiment. Hereinafter, a configuration different from the first and second embodiments will be described. Moreover, the same code | symbol is attached | subjected to the structure part similar to 1st and 2nd embodiment, and the description is abbreviate | omitted.

  FIG. 11 is a graph illustrating an example of light output control of the LDs 21a to 21c according to the third embodiment. FIG. 11 shows the response characteristics of the light outputs of the LDs 21a to 21c when the LDs 21a to 21c perform white display from the state where the light amount is 0, for example. In FIG. 11, the application start times ta0, tb0, and tc0 of the drive currents Ia1, Ib1, and Ic1 are the same time tS. A constant drive current Ia1 is applied to the red LD 21a during the period from time tS to tE. On the other hand, a driving current that increases in two stages is applied to the green LD 21b and the blue LD 21c during the same period. However, also in this case, at the time ta0 when the driving current Ia1 for outputting the light with the constant light amount Pa1 from the LD 21a is applied to the LD 21a, the driving current Ib1 for outputting the light with the constant light amounts Pb1 and Pc1 from the other LD 21b and 21c, respectively. , Ic1 is applied earlier than the time points tb2a and tc2a at which the LDs 21b and 21c are applied, respectively.

  That is, the light output control unit 582 applies a drive current having a current value (for example, 0.5Ib1) corresponding to a light amount (for example, 0.5Pb1) less than the steady light amount Pb1 to the green LD 21b at time tb0 (= tS). To do. Thereafter, the light output control unit 582 applies a drive current having a current value Ib1 corresponding to the steady light amount Pb1 to the LD 21b at time tb2a (= ta0 + TA / 2) when the light amount of the LD 21a becomes half of the steady value 0.5Pa1. To do.

  Similarly, the light output control unit 582 applies a drive current having a current value (for example, 0.5Ic1) corresponding to a light amount (for example, 0.5Pc1) less than the steady light amount Pc1 to the LD 21c at time tc0 (= tS). To do. Thereafter, the light output control unit 582 applies a drive current having a current value Ic1 corresponding to the steady light amount Pc1 to the LD 21c at time tc2a (= ta0 + TA / 2) when the light amount of the LD 21a becomes half of the steady value 0.5Pa1. To do.

  When the drive currents Ib1 and Ic1 are increased in two stages, as shown in FIG. 11, the times tb2a and tc2a at which the current values applied to the LD 21b and LD 21c are increased are the times when the LD 21a becomes half of the steady light quantity 0.5Pa1. It is desirable to be at or around the same time as ta2 (= tS + TA / 2). In this way, the light output change of the LD 21b and LD 21c in the rise time TA of the LD 21a (that is, the period from time ta0 to time ta1) can be brought close to the light output change of the LD 21a.

<Modification of Third Embodiment>
FIG. 12 is a graph illustrating an example of light output control of the LDs 21a to 21c according to the modification of the third embodiment. FIG. 12 shows the response characteristics of the light outputs of the LDs 21a to 21c when, for example, the LDs 21a to 21c perform white display from the state where the light quantity is zero. As shown in FIG. 12, the drive current applied to the green LD 21b may be increased in three or more stages up to a current value Pb1. Similarly, the drive current applied to the blue LD 21c may be increased in three or more stages up to the current value Pc1. However, also in this case, at the time ta0 when the driving current Ia1 for outputting the light with the constant light amount Pa1 from the LD 21a is applied to the LD 21a, the driving current Ib1 for outputting the light with the constant light amounts Pb1 and Pc1 from the other LD 21b and 21c, respectively. , Ic1 is applied earlier than the time points tb1 and tc1 when the LDs 21b and 21c are applied, respectively.

  Furthermore, as shown in FIGS. 11 and 12, when the current value applied to the LD 21b and LD 21c is increased in a plurality of stages, the amount of increase in the current value in each stage may be the same or different. Also good. Further, the increasing timing interval may be constant or different. These increasing amounts and increasing timings are preferably set by approximating the light output change of the LD 21a during the rising time TA (that is, the increasing tendency of the light amount). In this way, it is possible to approximate the light output changes of the LD 21b and LD 21c closer to the light output change of the LD 21a at the rise time TA of the LD 21a. Therefore, it is possible to significantly suppress or prevent the occurrence of color unevenness (for example, white balance collapse) that occurs in the scanning laser light 300 during the period in which all the LDs 21a to 21c have a constant light amount from the start of light emission of the LDs 21a to 21c.

<Summary of First to Third Embodiments>
According to the first to third embodiments described above, the projector unit 1 includes a plurality of LDs 21a to 21c and a light output control unit. The light output control unit includes a light output control unit 582 that controls the light outputs of the plurality of LDs 21a to 21c. When the white light is displayed from the state where the light amount is zero by the plurality of LDs 21a to 21c, the light output control unit 582 has the longest rise time TA required to output the white light amount Pa1 among the plurality of LDs 21a to 21c. When the driving current Ia1 that outputs the light of the white display light amount Pa1 from the LD 21a is applied to the LD 21a, the time ta0 is output from the other LD 21b and 21c as the driving currents Ib1 and Ic1 that output the light of the white display light amounts Pb1 and Pc1. , 21c (for example, tb0 and tc0 in FIGS. 8 and 10, tb2a and tc2a in FIG. 11, tb1 and tc1 in FIG. 12). (21st configuration)

  According to the twenty-first configuration, among the LDs 21a to 21c, the drive current Ia1 that outputs light of the white display light amount Pa1 from the LD 21a that has the longest rise time TA required to output the white display light amount Pa1 is supplied to the LD 21a. Is applied to the LDs 21b, 21c (for example, tb0, tc0 in FIGS. 8 and 10). The driving currents Ib1, Ic1 for outputting the light of the white light amounts Pb1, Pc1 from the other LDs 21b, 21c , Tb2a and tc2a in FIG. 11 and tb1 and tc1) in FIG. Therefore, the time ta1 when the LD 21a outputs the light with the light amount Pa1 for white display can be brought closer to the times tb1 and tc1 when the LD 21b and 21c output the light with the light amounts Pb1 and Pc1 for white display. Therefore, when the plurality of LDs 21a to 21c perform white display, it is possible to improve color unevenness caused by a difference in light emission delay between the LDs 21a to 21c.

  In addition, since the color unevenness of the light 300 at the rise time TA of the plurality of LDs 21a to 21c having different emission colors can be improved, deterioration of the color tone balance (for example, white balance) of the light 300 can also be suppressed.

  Further, in the light output control unit of the projector unit 1 having the twenty-first configuration, the light output control unit 582 controls the light output based on the time difference between the rise times TA, TB, and TC of the LDs 21a to 21c. The time ta1 when the amount of light reaches the light amount Pa1 for white display and the time points tb1 and tc1 when the light amounts of the other LDs 21b and 21c reach the light amounts Pb1 and Pc1 for white display may be the same. (Twenty-second configuration)

  According to the twenty-second configuration, the time point ta1 at which the LD 21a outputs light of the white light amount Pa1 is the same as the time points tb1 and tc1 at which the LDs 21b and 21c output light of the white light amounts Pb1 and Pc1. Thus, the light output is controlled. Therefore, the color unevenness in the rising time TA of the light 300 output from the LDs 21a to 21c can be further improved.

  Alternatively, in the light output control unit of the projector unit 1 having the twenty-first configuration, the light output control unit 582 is configured so that the light amount of the LD 21a is based on the time differences between the rising times TA, TB, and TC of the plurality of LDs 21a to 21c. May be the same as the time when the light quantity of the LD 21b and 21c reaches the predetermined ratio with respect to the white light quantity Pb1 and Pc1, respectively. (23rd configuration)

  Furthermore, in the twenty-third configuration, the predetermined ratio may be 50%. (24th configuration)

  According to the twenty-third and twenty-fourth configurations, time-average color unevenness in the rising time TA of the LD 21a can be improved. Therefore, it is possible to suppress deterioration in the color tone balance (for example, white balance) of the light 300 output from the plurality of LDs 21a to 21c.

  Further, in the light output control unit of the projector unit 1 having any one of the first to twenty-fourth configurations, the light output control unit 582 has a light amount less than the white light amounts Pb1 and Pc1 (for example, 0.5Pb1,. After applying a drive current of a first current value (for example, 0.5Ib1, 0.5Ic1) that causes the light output of 5Pc1) to be LD21b, 21c, to LD21b, 21c, the light output of white display light amounts Pb1, Pc1 is changed to LD21b, The drive currents having the second current values Ib1 and Ic1 to be 21c may be applied to the LDs 21b and 21c. (25th configuration)

  According to the twenty-fifth configuration, the LDs 21b and 21c output light with a light amount lower than the light amounts Pb1 and Pc1 for white display (for example, 0.5Pb1 and 0.5Pc1), and then the light amounts Pb1 and Pc1 for white display. Light output. Therefore, the change in the amount of light in the LD 21b and 21c during the periods TB and TC from the start of light emission until the light output of the white display amounts Pb1 and Pc1 can be made closer to the change in the amount of light in the LD 21a during the rise time TA. Therefore, it is possible to further reduce color unevenness and color tone balance deterioration of the light 300 output from the plurality of LDs 21a to 21c.

  Further, in the light output control unit of the projector unit 1 having any one of the first to 25th configurations, the light output control unit 582 uses the drive current of the LDs 21b and 21c as the white display light amount Pb1 and the light of the light Pc1 as the LD 21b. The current values Ib1 and Ic1 output from 21c may be increased in a plurality of stages (see FIGS. 11 and 12). (26th configuration)

  According to the twenty-sixth configuration, the light amount change of the LDs 21b and 21c in the periods TB and TC from the start of light emission to the light output of the white display light amounts Pb1 and Pc1 is made closer to the light amount change of the LD 21a in the rise time TA. be able to. Accordingly, it is possible to further reduce color unevenness and color tone balance deterioration of the light 300 output from the plurality of LDs 21a to 21c.

  In addition, the light output control unit of the projector unit 1 having any one of the 21st to 26th configurations includes a plurality of LDs 21a to 23c based on detection results of the PDs 23a to 23c that detect the light amounts of the LDs 21a to 21c. You may further provide the calculation part 583 which calculates each rise time TA, TB, and TC of 21c. (27th configuration)

  According to the twenty-seventh configuration, the amount of light of each of the plurality of LDs 21a to 21c can be detected as appropriate, and the light output control unit 582 uses the rise times TA, TB, and TC based on the detection results of the plurality of LDs 21a to 21c. Light output can be controlled. Therefore, even if the rise times TA, TB, and TC of the LDs 21a to 21c change due to, for example, changes in element temperature or element deterioration, the light output control unit 582 can perform light output control in accordance with the changes. it can.

  Further, in the light output control unit of the projector unit 1 having the twenty-seventh configuration, the light output control unit 582 emits the scanning laser light 300 that is projected and scanned on the projection surface 102a to form an image on the projection surface 102a. When the scanning laser beam 300 scans the invalid projection area 102c on the projection surface 102a that is output from the plurality of LDs 21a to 21c and on which no image is formed, the light output control unit 582 causes the plurality of LDs 21a to 21c to emit light, and the calculation unit 583. May calculate the rising times TA, TB, and TC based on the detection results of the PDs 23a to 23c when the scanning laser beam 300 scans the invalid projection area 102c. (28th configuration)

  According to the twenty-eighth configuration, when the scanning laser beam 300 scans the invalid projection area 102c on the projection surface 102a, the light quantity of each of the plurality of LDs 21a to 21c can be detected as appropriate. The rise times TA, TB, and TC of 21c can be calculated. Therefore, by controlling the light output suitable for the actual state of each of the LDs 21a to 21c, the color unevenness of the scanning laser light 300 can be improved, and the quality of the image formed on the projection surface 102a can be improved.

  In the light output control unit of the projector unit 1 having any one of the 21st to 28th configurations, a memory (not shown) for storing video information of images formed by the light outputs of the plurality of LDs 21a to 21c is provided. Further, the light output control unit 582 may be configured to analyze the video information and control the light outputs of the plurality of LDs 21a to 21c based on the analysis result. (29th configuration)

  According to the twenty-ninth configuration, the light output of the LDs 21a to 21c can be controlled based on the analysis result of the video information of the video formed on the projection surface 102a.

<Fourth embodiment>
Next, a fourth embodiment will be described. In the fourth embodiment, unlike the first embodiment, in the forward scanning laser light 300a, the portion where the light amount is insufficient due to the rise times TA, TB, and TC of the plurality of LDs 21a to 21c is determined as the backward scanning laser light 300b. Complement with the amount of light. Hereinafter, a configuration different from the first embodiment will be described. Moreover, the same code | symbol is attached | subjected to the component similar to 1st-3rd embodiment, and the description is abbreviate | omitted.

  FIG. 13 is a schematic diagram locally showing the scanning range of the scanning laser beam 300 that is continuously reciprocated. FIG. 13 shows, for example, a range on the projection surface 102a surrounded by a solid line A in FIG. As shown in FIG. 13, the scanning pitch (ie, scanning interval) in the Y direction of each scanning laser beam 300 is larger than the spot diameter 302a of the forward scanning laser beam 300a and the spot diameter 302b of the backward scanning laser beam 300b. small. Therefore, part of the scanning laser beams 300a and 300b that are continuously reciprocally scanned overlap each other.

  The hatched portions in FIG. 13 are the scanning range 301a of the forward scanning laser light 300a and the scanning range 301b of the backward scanning laser light 300b, respectively, which overlap in the overlapping scanning range 301c. Hereinafter, the center position in the X direction of the beam spots 302a and 302b of the scanning laser beams 300a and 300b is referred to as a scanning position. The first scanning position H1 is a scanning position at the start of light emission of the forward scanning laser light 300a, and is a scanning position at the time when light emission of the backward scanning laser light 300b is stopped. The second scanning position H2 is a scanning position at the time when emission of the forward scanning laser light 300a is stopped, and is a scanning position at the time when light emission of the backward scanning laser light 300b starts.

  Here, as described above, the plurality of LDs 21a to 21c have rise times TA, TB, and TC, respectively, at the start of light emission. Therefore, color unevenness occurs in the scanning laser beam 300 from the scanning position at the time of light emission to a predetermined position after the rising time has elapsed. In the present invention, the amount of light that decreases in a region where a part of the scanning laser beams 300a and 300b that are continuously reciprocated overlap (that is, the overlapping scanning range 301c) is complemented to reduce such color unevenness or To prevent. That is, in the forward scanning laser light 300a, a portion where the light amount is insufficient due to the rise times TA, TB, and TC of the plurality of LDs 21a to 21c is supplemented with the light amount of the backward scanning laser light 300b. Similarly, in the backward scanning laser light 300b, a portion where the light amount is insufficient due to the rise times TA, TB, and TC of the plurality of LDs 21a to 21c is supplemented with the light amount of the forward scanning laser light 300a.

  In the following, the principle of compensating for the insufficient light quantity of the scanning laser beam 300a by using averaging of the light quantity will be described. However, in order to facilitate understanding of this principle, the light output of the red component of the scanning laser light 300 (ie, the red LD 21a). The control will be mainly described. However, the light output control of the other color components (that is, the green LD 21b and the blue LD 21c) of the scanning laser beam 300 is similarly performed.

  First, the optical outputs of the forward and backward scanning laser beams 300a and 300b are similarly controlled between the first scanning position H1 and the second scanning position H2. FIG. 14 is a graph showing an example of the light output control of the red LD 21a in the fourth embodiment. FIG. 14 shows light output control of the red LD 21a from the start of light emission to the stop of light emission of the forward and backward scanning laser beams 300a and 300b.

  In FIG. 14, a time point tS is a time point when the red component projection of the scanning laser light 300 (that is, the light emission of the LD 21a) for forming a projection image based on the video information on the projection surface 102 is started. Time tS corresponds to the time when the center position in the X direction of the beam spot 302a of the forward scanning laser beam 300a is at the first scanning position H1, and the center position in the X direction of the beam spot 302b of the backward scanning laser light 300b is This corresponds to the time point at the second scanning position H2. The time point tE is a time point at which the light emission of the LD 21a is stopped. The time point tE corresponds to the time point when the X-direction center position of the forward beam spot 302a is at the second scanning position H2, and corresponds to the time point when the X-direction center position of the return beam spot 302b is at the first scanning position H1. To do.

  Further, the time point ta1 is a time point after the rising time TA from the time point tS, and is a time point when the light output of the LD 21a reaches the steady light amount Pa1 corresponding to the constant drive current Ia1. The time point ta3 is a time point that is the same time as the rise time TA before the time point tE. The time point ta4 is a time point before the light supplement time ΔTa from the time point tE, and is a time point at which the light of the light amount Pa2 that is larger than the light amount Pa1 and the light amount Pa2 is output from the LD 21a. A driving current having a current value Ia1 is applied to the LD 21a between time points tS and ta4, and a driving current having a current value Ia2 is applied between time points ta4 and tE. In FIG. 14, the light supplement time ΔTa is set to 0.5 TA, for example, and the correction light amount ΔPa is set to 0.5 Pa1, for example. However, the present invention is not limited to these examples, and the light supplement time ΔTa may be equal to or shorter than the rising time TA (0 <ΔTa ≦ TA), and the light amount Pa2 may be equal to or less than twice the light amount Pa1 (that is, ΔPa = Pa2). -0 <ΔPa ≦ Pa1 at Pa1).

  Next, the apparent light quantity of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 that the person who sees the projection surface 102a feels when the light output control as shown in FIG. 14 is performed will be described. In the following, the apparent light amount of the red component of the scanning laser light 300 will be described in the same manner as in FIG. 14, but it goes without saying that the apparent light amount of the other color components (that is, the green component and the blue component) can be similarly felt. It will be.

  FIGS. 15A to 15C are views for explaining the apparent light amount of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 in the fourth embodiment. FIG. 15A is a diagram showing a light output change of the forward scanning laser light 300a scanned from the first scanning position H1 to the second scanning position H2 in the fourth embodiment. FIG. 15B is a diagram showing a change in light output of the backward scanning laser light 300b scanned from the second scanning position H2 to the first scanning position H1 in the fourth embodiment. FIG. 15C is a diagram illustrating a change in the apparent light amount of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 in the fourth embodiment.

  15A to 15C, it should be noted that the horizontal axis of the graph indicates the scanning position of the scanning laser beam 300, unlike FIG. Therefore, the graph of the optical output and the drive current in FIG. 15A related to the forward scanning laser light 300a and the direction of the horizontal axis are reversed from those in FIG. 15B related to the backward scanning laser light 300b. Further, the graph of FIG. 15C represents the apparent light amount in the overlapping scanning range 301C (see FIG. 13) between the first scanning position H1 and the second scanning position H2 that the human senses due to the above-described effect of averaging the light amount. .

  The scanning position H3 indicates the scanning position of the forward scanning laser light 300a after the rising time TA from the start of light emission at the first scanning position H1. The scanning position H6 indicates the scanning position of the forward scanning laser light 300a before the light supplement time ΔTa before the light emission stop at the second scanning position H2. In the forward scanning laser light 300a, the scanning positions H1 to H3 correspond to the scanning range HA at the rising time TA (hereinafter referred to as the rising scanning range HA), and the scanning positions H2 to H6 are supplemented before the light emission is stopped. This corresponds to a scanning range in the optical time ΔTa (hereinafter referred to as an auxiliary light scanning range ΔHa).

  The scanning position H4 indicates the scanning position of the backward scanning laser light 300b after the rising time TA from the start of light emission at the second scanning position H2. The scanning position H5 indicates the scanning position of the backward scanning laser light 300b before the light supplement time ΔTa before the light emission stop at the first scanning position H1. In the backward scanning laser beam 300b, the scanning position H2 to H4 corresponds to the rising scanning range HA, and the scanning position H1 to H5 corresponds to the auxiliary light scanning range ΔHa.

  In the forward and backward scanning laser beams 300a and 300b, the light amount Pa2 in the auxiliary light scanning range ΔHa is larger than the light amount Pa1 corresponding to the drive current Ia1. Further, the distance between the scanning positions H1 to H3 in the forward scanning laser light 300a and the distance between the scanning positions H2 to H4 in the backward scanning laser light 300b are the same HA. Further, the distances in the X direction between the scanning positions H2 to H6 in the forward scanning laser light 300a and between the scanning positions H1 to H5 in the backward scanning laser light 300b are the same ΔHa. As described above, since 0 <ΔTa ≦ TA, the distance ΔHa is equal to or less than the distance HA (0 <ΔHa ≦ HA).

  When the forward and backward scanning laser beams 300a and 300b are scanned, the amount of light between the scanning positions H1 and H2 is felt as shown in the graph of FIG. 15C by human vision. That is, the amount of light that is insufficient in the rising scanning range HA (between scanning positions H1 and H3) of the forward scanning laser beam 300a is the corrected light amount of the supplementary scanning range ΔHa (between scanning positions H1 and H5) of the backward scanning laser beam 300b. Complemented with ΔPa. Further, the amount of light that is insufficient in the rising scanning range HA (between the scanning positions H2 and H4) of the backward scanning laser beam 300b is the correction light amount of the supplementary scanning range ΔHa (between the scanning positions H2 and H6) of the outgoing scanning laser beam 300a. Complemented with ΔPa. Therefore, the amount of light visually perceived by humans between the scanning positions H1 and H3 and between the scanning positions H2 and H4 can be brought close to the steady light amount Pa1. Therefore, it is possible to improve the decrease in light amount due to the light emission delay at the start of light emission of the LD 21a.

  First, the light output control processing of the LDs 21a to 21c will be described. FIG. 16 is a flowchart for explaining an example of the light output control processing of the LDs 21a to 21c according to the fourth embodiment. In the following processing, S201 to S204 are performed during the retrace period, and S205 is performed during the trace period. The light output control process illustrated in FIG. 16 is also applied to fifth and sixth embodiments described later.

  First, in the retrace period, when the optical axis of the scanning laser beam 300 scans the invalid projection region 102c, the light output control unit 582 applies LDs 21a to 21c to a predetermined light amount (for example, Pa1, Pb1) by applying the drive currents Ia1 to Ic1. , Pc1) to emit light (S201). The application times of the drive currents Ia1 to Ic1 may be longer than the rise times TA, TB, and TC of the LDs 21a to 21c, respectively. The optical outputs of the LDs 21a to 21c are detected by the PDs 23a to 23c, respectively (S202). The calculation unit 583 calculates the rise times TA, TB, and TC of the LDs 21a to 21c based on the detection results of the PDs 23a to 23c (S203). In addition, the light output control unit 582 captures the video data output from the video processing unit 581 into a memory (not shown), and performs image analysis of the projection image projected on the projection surface 102a in the trace period based on the video data. Perform (S204). That is, the color information and luminance information of the projection image formed during the trace period are analyzed.

  Next, in the trace period, the light output control unit 582 performs a plurality of operations based on the image analysis result, the calculation result of the calculation unit 583, and the light output correction information of the plurality of LDs 21a to 21c read from the storage unit 57. The light output of the LDs 21a to 21c is controlled (S205). The light output correction information is stored in the storage unit 57, and is used for compensating for the shortage of light quantity at the rising times TA, TB, TC of the plurality of LDs 21a to 21c (for example, a supplementary time ΔTa described later). And correction light quantity ΔPa). Then, the process returns to S201.

  In the above, the optical outputs of the forward and backward scanning laser beams 300a and 300b are averaged in the overlapping scanning range 301c (see FIG. 13), so that the ideal light output having the steady light amounts Pa1, Pb1, and Pc1 is obtained. The case where it is performed was explained. FIG. 17 is a diagram illustrating an ideal light output change of the LD 21a and an actual light output change in the forward and backward scanning laser lights 300a and 300b when the light output of the steady light amount Pa1 is performed. FIG. 17 shows a change in the light output of the scanning laser beam 300 of the LD 21a. Since the same applies to the LD 21b and LD 21c, the description thereof will be omitted. Further, the upper graph in FIG. 17 shows the change in the light amount at the ideal light output, and the middle graph shows the actual light output with the forward scanning laser light 300a scanned from the first scanning position H1 to the second scanning position H2. The lower graph shows the actual light output change in the backward scanning laser light 300b scanned from the second scanning position H2 to the first scanning position H1.

  As shown in the upper graph of FIG. 17, the ideal rising of the optical output at the first and second scanning positions H1 and H2 both rapidly increases. When such light output is performed, the rise at the start of light emission at the actual light output at the first and second scanning positions H1 and H2 is suddenly increased, and the fall at the stop of light emission is sharply reduced. There is a need. That is, at the start of light emission, a driving current (see FIG. 24 described later) equal to or higher than the oscillation threshold current Is is supplied to the LD 21a, and the scanning laser light 300 is rapidly increased to the light amount Pa1. Further, when light emission is stopped, the drive current supplied to the LD 21a is decreased from a current value greater than or equal to the oscillation threshold current Is to a current value less than the oscillation threshold current Is, and the scanning laser light 300 is rapidly decreased from the light amount Pa1. .

  However, if the amount of light is suddenly increased at the start of light emission, a decrease in the amount of light (so-called falling) due to the light emission delay occurs. Therefore, the light amount of the light output in the rising scanning range HA (between the scanning positions H1 to H3) of the forward scanning laser light 300a is insufficient and becomes lower than the light amount Pa1 as shown in the middle graph of FIG. Similarly, the amount of light in the rising scanning range HA (between the scanning positions H2 and H4) of the backward scanning laser beam 300b is insufficient and becomes lower than the light amount Pa1 as shown in the lower graph of FIG. Therefore, in the supplementary scanning range ΔHa (between scanning positions H2 to H6) of the forward scanning laser beam 300a, light output is performed with the light amount Pa2 = (Pa1 + ΔPa), and the supplementary scanning range ΔHa (scanning position) of the backward scanning laser light 300b. (Between H1 and H5), the light output is performed with the light amount Pa2. By performing such light output, the amount of light that is insufficient in the rising scanning range HA (between the scanning positions H1 to H3) of the forward scanning laser light 300a is averaged with the corrected light amount ΔPa of the backward scanning laser light 300b. To make up for it. Further, the amount of light that is insufficient in the rising scanning range HA (between the scanning positions H2 and H4) of the backward scanning laser beam 300b is compensated by being averaged with the correction light amount ΔPa of the traveling scanning laser beam 300a. Therefore, the ideal light output shown in the upper graph of FIG. 17 is realized by averaging the light outputs of the forward and backward scanning laser lights 300a and 300b in the overlapping scanning range 301c (see FIG. 13).

  Note that, unlike the illustration of FIG. 17, if the rise of the ideal light output at least one of the first and second scanning positions H1 and H2 is gentle enough that no light emission delay occurs in the actual light output. In the actual scanning laser light 300 in which light emission is started at the one scanning position, no light emission delay occurs. Therefore, the fall (reduction in the amount of light) at the time of stopping the light emission at the one scanning position can be made gentle as well. Hereinafter, these cases will be described.

<Modification of Fourth Embodiment>
First, a case where an ideal light output rises gently on the first scanning position H1 side will be described. FIG. 18 shows an ideal optical output change of the LD 21a when the optical output is gently raised in the rising scanning range HA1 (between the scanning positions H1 to H0a) on the first scanning position H1 side, and actual in the forward and return paths. It is a figure which shows the optical output change. FIG. 18 shows a change in the light amount of the light output of the LD 21a with respect to the scanning position of the scanning laser beam 300 on the projection surface 102 in the scanning direction. Since the same applies to the LD 21b and LD 21c, the description thereof will be omitted. The upper graph in FIG. 18 shows the change in the light amount at the ideal light output, and the middle graph shows the actual light output change in the forward scanning laser light 300a scanned from the first scanning position to the second scanning position. The lower graph shows the actual light output change in the backward scanning laser light 300b scanned from the second scanning position to the first scanning position.

  As shown in the upper graph of FIG. 18, the ideal rise of the optical output on the scanning position H1 side is the rising scanning range HA1 (between the scanning positions H1 to H0a) until the light amount reaches the steady light amount Pa1 from 0. ) Will change smoothly. That is, the width (scanning distance) of the rising scanning range HA1 is wider than the width of the rising scanning range HA when a light emission delay occurs in the actual scanning laser beam 300. In other words, on the first scanning position H1 side, the rise of the ideal light output is later than the rise time TA due to the light emission delay at the actual light output. In such a case, a light emission delay does not occur at the rise of the scanning laser beam 300a in the forward path (change in light output between the scanning positions H1 to H0a), and a shortage of light amount due to it does not occur. Therefore, the light output at the start of light emission of the forward scanning laser light 300a changes smoothly to the same extent as the ideal light output. Further, the light output between the scanning positions H1 to H0a before stopping the emission of the scanning laser light 300b in the backward path also changes gently in the same manner as the ideal light output.

  On the other hand, in FIG. 18, the rise of the ideal light output at the second scanning position H2 increases rapidly as in FIG. In such a case, the trailing edge of the forward scanning laser beam 300a is rapidly reduced. In addition, the rise of the scanning laser beam 300b in the backward path is suddenly increased, but a decrease in the amount of light (so-called falling) due to the light emission delay occurs. Therefore, the amount of light in the rising scanning range HA (between the scanning positions H2 and H4) of the scanning laser beam 300b in the backward path is insufficient and lower than the light amount Pa1 as shown in the lower graph of FIG. Therefore, in the supplementary light scanning range ΔHa (between the scanning positions H2 and H6) immediately before stopping the emission of the forward scanning laser light 300a, the light output is performed with the light amount Pa2 = (Pa1 + ΔPa), so that the backward scanning laser light 300b is started up. The amount of light that is insufficient in the scanning range HA (between the scanning positions H2 and H4) is compensated by the correction light amount ΔPa of the forward scanning laser light 300a. That is, the ideal light output at the second scanning position H2 shown in the upper graph of FIG. 18 is in the scanning ranges H2 to H4 immediately before stopping the emission of the forward scanning laser light 300a in the overlapping scanning range 301c (see FIG. 13). And the light output in the scanning range H2 to H4 immediately after the start of light emission of the backward scanning laser light 300b.

<Other Modifications of Fourth Embodiment>
Next, a case where the ideal light output rises gently on the second scanning position H2 side will be described. FIG. 19 shows an ideal change in the optical output of the LD 21a when the optical output rises gently in the rising scanning range HA2 (between the scanning positions H2 and H0b) on the second scanning position H2 side and the actual in the forward and return paths. It is a figure which shows the optical output change. FIG. 19 shows a change in the light amount of the light output of the LD 21a with respect to the scanning position of the scanning laser light 300 on the projection surface 102 in the scanning direction. Since the same applies to the LD 21b and LD 21c, the description thereof will be omitted. The upper graph in FIG. 19 shows the change in the light amount at the ideal light output, and the middle graph shows the actual light output change in the forward scanning laser light 300a scanned from the first scanning position to the second scanning position. The lower graph shows the actual light output change in the backward scanning laser light 300b scanned from the second scanning position to the first scanning position.

  As shown in the upper graph of FIG. 19, the ideal rise of the optical output at the first scanning position H1 increases rapidly as in FIG. In such a case, the rising of the scanning laser beam 300a in the forward path is suddenly increased, but a decrease in the amount of light (so-called falling) due to the light emission delay occurs. Therefore, the light amount in the rising scanning range HA (between the scanning positions H1 to H3) of the forward scanning laser light 300a is insufficient and lower than the light amount Pa1 as shown in the middle graph of FIG. Therefore, in the supplementary light scanning range ΔHa (between the scanning positions H1 to H5) just before stopping the emission of the backward scanning laser light 300b, the light output is performed with the light amount Pa2 = (Pa1 + ΔPa), so that the forward scanning laser light 300a is started up. The amount of light that is insufficient in the scanning range HA (between the scanning positions H1 and H3) is compensated by the corrected amount of light ΔPa of the scanning laser light 300b in the backward path. That is, the ideal light output at the first scanning position H1 shown in the upper graph of FIG. 19 is in the scanning ranges H1 to H3 immediately after the start of the emission of the forward scanning laser light 300a in the overlapping scanning range 301c (see FIG. 13). And the light output in the scanning range H1 to H3 immediately before stopping the emission of the backward scanning laser light 300b.

  On the other hand, in FIG. 19, the ideal rise of the optical output on the scanning position H2 side is the rising scanning range HA2 (between the scanning positions H2 to H0b) from when the light amount reaches 0 to the constant light amount Pa1 in the laser oscillation mode. ) Will change smoothly. That is, the width (scanning distance) of the rising scanning range HA2 is wider than the width of the rising scanning range HA when an emission delay occurs in the actual scanning laser light 300. In other words, on the second scanning position H2 side, the rise of the ideal light output is later than the rise time TA due to the light emission delay at the actual light output. When such light output is performed, no light emission delay occurs at the rising edge of the scanning laser light 300b in the backward path (change in the light output between the scanning positions H2 to H0b), and there is no shortage of light amount due to it. For this reason, the light output at the start of light emission of the backward scanning laser light 300b changes smoothly to the same extent as the ideal light output. Further, the light output between the scanning positions H2 to H0b before the emission of the forward scanning laser light 300a stops also changes smoothly in the same manner as the ideal light output.

  When the ideal light output rises gently on both the first scanning position H1 side and the second scanning position H2 side, no light emission delay occurs at the start of light emission with actual light output. Therefore, the change in the light output of the forward and return scanning laser beams 300a and 300b is the same as the change in the ideal light output.

<Fifth Embodiment>
Next, a fifth embodiment will be described. In the fifth embodiment, the correction light amount ΔPa and the light supplement time ΔTa are determined according to the accumulated light amount S1 that is insufficient at the rise times TA, TB, and TC of the LDs 21a to 21b. Hereinafter, a configuration different from that of the fourth embodiment will be described. Moreover, the same code | symbol is attached | subjected to the component similar to 1st-4th embodiment, and the description is abbreviate | omitted.

  FIG. 20 is a graph showing an example of the light output control of the red LD 21a in the fifth embodiment. In the following, the light output control of the LD 21a is described as an example, but the other LDs 21b and 21c can be controlled similarly.

  FIG. 20 shows light output control of the red LD 21a from the start of light emission to the stop of light emission of the forward and backward scanning laser beams 300a and 300b. In FIG. 20, the shortage amount S1 is a cumulative amount of light quantity that is deficient (decreased) due to light emission delay during the rise time TA. That is, the shortage amount S1 is a time integration amount at the rising time TA of the light amount difference (Pa1-Pa) between the steady light amount Pa1 corresponding to the drive current Ia1 and the actual light amount Pa. The correction amount S2 is a cumulative light amount obtained by time-integrating the correction light amount ΔPa during the light supplement time ΔTa.

  As shown in FIG. 20, the light output of the LD 21a is controlled so that the correction amount S2 is the same as the shortage amount S1. In other words, the correction light amount ΔPa and the light supplement time ΔTa are set so as to satisfy S1 = S2 = ΔPa × ΔTa. The setting method is not particularly limited. For example, the correction light amount ΔPa and the light supplement time ΔTa may be set within a range that satisfies this condition. Alternatively, one of the correction light amount ΔPa and the supplementary light time ΔTa may be a fixed value, and the other may be determined as appropriate based on the above conditions.

  Next, the apparent light quantity of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 that a person who sees the projection surface 102a feels when the light output control as shown in FIG. 20 is performed will be described. In the following, the apparent light amount of the red component of the scanning laser beam 300 will be described in the same manner as in FIG. 20, but it goes without saying that the apparent light amount of the other color components (that is, the green component and the blue component) can be felt in the same manner. It will be.

  21A to 21C are diagrams for explaining the apparent light amount of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 in the fifth embodiment. FIG. 21A is a diagram showing a light output change of the forward scanning laser light 300a scanned from the first scanning position H1 to the second scanning position H2 in the fifth embodiment. FIG. 21B is a diagram illustrating a change in light output of the backward scanning laser light 300b scanned from the second scanning position H2 to the first scanning position H1 in the fifth embodiment. FIG. 21C is a diagram illustrating a change in the apparent light amount of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 in the fifth embodiment.

  21A to 21C, it should be noted that the horizontal axis of the graph indicates the position of the scanning laser light 300 in the X direction, unlike FIG. Therefore, the optical output and drive current graph shape of FIG. 21A related to the forward scanning laser light 300a and the direction of the horizontal axis are reversed from those of FIG. 21B related to the backward scanning laser light 300b. Further, the graph of FIG. 21C represents the apparent light amount in the overlapping scanning range 301C (see FIG. 13) between the first scanning position H1 and the second scanning position H2 that the human senses due to the above-described effect of averaging the light amount. .

  In FIG. 21A and FIG. 21B, the shortage amount s1 is an integral amount with respect to the scanning distance HA of the light amount that is insufficient due to the light emission delay at the rising time TA, and corresponds to the shortage amount S1 in FIG. Further, the correction amount s2 is an integral amount with respect to the scanning distance ΔHa of the correction light amount ΔPa during the light supplement time ΔTa, and corresponds to the correction amount S2 in FIG.

  When the forward and backward scanning laser beams 300a and 300b are scanned, the amount of light between the scanning positions H1 and H2 is felt as shown in the graph of FIG. 21C by human vision. That is, the shortage amount s1 in the rising scanning range HA (that is, between the scanning positions H1 to H3) of the forward scanning laser beam 300a is the supplementary scanning range ΔHa (that is, between the scanning positions H1 to H5) of the backward scanning laser beam 300b. Is compensated by the correction amount s2. Further, the shortage amount s1 in the rising scanning range HA (that is, between the scanning positions H2 to H4) of the backward scanning laser beam 300b is the supplementary scanning range ΔHa (that is, between the scanning positions H2 to H6) of the outgoing scanning laser beam 300a. Is compensated by the correction amount s2. Therefore, the amount of light visually perceived by humans between the scanning positions H1 and H3 and between the scanning positions H2 and H4 can be brought close to the steady light amount Pa1. Therefore, it is possible to improve the decrease in light amount due to the light emission delay at the start of light emission of the LD 21a.

  In the above example, the LD 21a is controlled so that the shortage amount S1 in FIG. 20 is the same as the correction amount S2, but the present invention is not limited to this example. The LD 21a may be controlled so that the deficiency s1 in FIGS. 21A to 21C is the same as the correction amount s2. Further, as described above, the light output of the green LD 21b and the blue LD 21c is similarly controlled. Therefore, by the above-described light output control, the X-direction edge portion of the overlapping scanning range 301c where the forward and backward scanning laser beams 300a and 300b overlap, that is, the scanning range between the scanning positions H1 to H3 and the scanning positions H2 to H5. It is possible to reduce or prevent the color unevenness caused by the light emission delay of each of the LDs 21a to 21c in the scanning range.

<Sixth Embodiment>
Next, a sixth embodiment will be described. In addition, although 6th Embodiment demonstrates and demonstrates green LD21b, it is the same also about other LD21a, 21c. FIG. 22 is a graph showing an example of the light output control of the green LD 21b in the sixth embodiment. As shown in FIG. 22, in the sixth embodiment, the rising time TB of the green LD 21b is equally divided into three divided times ΔTb, and the amount of light insufficient at each divided time ΔTb is divided into three stages of corrected light amounts ΔPb1 to ΔPb3. To compensate. Below, a different structure from 4th and 5th embodiment is demonstrated. Moreover, the same code | symbol is attached | subjected to the component similar to 1st-5th embodiment, and the description is abbreviate | omitted.

  In FIG. 22, the time length of each division time ΔTb is the same. The time point tb5 is a time point ΔTb after the time point tS, and light of the light amount Pb3 is output from the LD 21b. The time point tb6 is a time point 2ΔTb after the time point tS, and light of the light amount Pb2 is output from the LD 21b. The time point tb1 is a time point after the rising time TB (= 3ΔTb) from the time point tS, and the light of the steady light amount Pb1 corresponding to the constant drive current Ib1 is output from the LD 21b. Each light quantity is 0 <Pb3 <Pb2 <Pb1.

  The time point tb3 is a time point 3ΔTb before the time point tE, the time point tb7 is a time point 2ΔTb before the time point tE, and the time point tb8 is a time point ΔTb before the time point tE. From time tb3 to time tb7, the light output control unit 582 applies the drive current Ib2 to the LD 21b and causes the light of the light amount Pb4 (= Pb1 + ΔPb1) to be output from the LD 21b. In addition, from time tb7 to time tb8, the light output control unit 582 applies the drive current Ib3 to the LD 21b and causes the LD 21b to output light of the light amount Pb5 (= Pb4 + ΔPb2). Further, from time tb8 to time tE, the drive current Ib4 is applied to the LD 21b, and light of the light amount Pb6 (= Pb5 + ΔPb3) is output from the LD 21b. In addition, each light quantity is Pb1 <Pb4 <Pb5 <Pb6.

  Further, each of the correction light amounts ΔPb1 to ΔPb3 is determined according to a change in the light output during the rise time TB of the LD 21b. In particular, it is preferable to make the step-like changes of the correction light amounts ΔPb1 to ΔPb3 close to the light output change at the rise time TB. For example, the correction light amount ΔPb1 between the time point tb3 and the time point tb7 is set to a numerical value in the range of 0 <ΔPb1 ≦ | Pb1−Pb2 | according to the change in the light output between the time point tb6 and the time point tb1, and in FIG. -Pb2 | / 2 is set. Further, the correction light amount ΔPb2 between the time point tb7 and the time point tb8 is set to a numerical value within the range of 0 <ΔPb2 ≦ | Pb2−Pb3 | according to the change in the light output between the time point tb5 and the time point tb6. In FIG. -Pb3 | / 2 is set. Further, the correction light amount ΔPb3 between the time point tb8 and the time point tE is set to a numerical value within a range of 0 <ΔPb3 ≦ Pb3 according to the change in the light output between the time point tS and the time point tb5. In FIG. 22, (Pb3) / 2 is set. Is set.

  Next, the apparent light quantity of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 that the person who sees the projection surface 102a feels when the light output control as shown in FIG. 22 is performed will be described. In the following, the apparent light amount of the green component of the scanning laser beam 300 will be described in the same manner as in FIG. 22, but it goes without saying that the apparent light amount of other color components (that is, the red component and the blue component) can be similarly felt. It will be.

  FIGS. 23A to 23C are diagrams for explaining the apparent light amount of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 in the sixth embodiment. FIG. 23A is a diagram showing a light output change of the forward scanning laser light 300a scanned from the first scanning position H1 to the second scanning position H2 in the sixth embodiment. FIG. 23B is a diagram showing a change in light output of the backward scanning laser light 300b scanned from the second scanning position H2 to the first scanning position H1 in the sixth embodiment. FIG. 23C is a diagram illustrating a change in the apparent light amount of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 in the sixth embodiment.

  Note that in FIGS. 23A to 23C, the horizontal axis of the graphs indicates the position of the scanning laser light 300 in the X direction, unlike FIG. 22. Therefore, the graph shape of the optical output and the drive current in FIG. 23A related to the forward scanning laser light 300a and the direction of the horizontal axis are reversed from those in FIG. 23B related to the backward scanning laser light 300b. FIG. 23C shows the apparent light quantity in the overlapping scanning range 301C (see FIG. 13) between the first scanning position H1 and the second scanning position H2 that the human senses due to the above-described effect of averaging the light quantity.

  The first scanning position H1 is a scanning position at the start of emission of the scanning laser light 300a in the forward path of the LD 21b, and is also a scanning position at the stop of light emission of the scanning laser light 300b in the backward path of the LD 21b. The second scanning position H2 is a scanning position when the emission of the scanning laser light 300a in the forward path of the LD 21b is stopped, and is also a scanning position when the emission of the scanning laser light 300b in the backward path of the LD 21b is started. The scanning position H3 is a scanning position after the rise time TB from the start of light emission at the first scanning position H1 in the forward scanning laser light 300a, and from the stop of light emission at the first scanning position H1 in the backward scanning laser light 300b. Is also the scanning position before 3ΔTb (= TB). The scanning position H4 is a scanning position 3ΔTb (= TB) before the emission stop at the second scanning position H2 in the forward scanning laser light 300a, and the first scanning position H1 in the backward scanning laser light 300b. This is also the scanning position after the rise time TB from the start of light emission at.

  In the forward scanning laser light 300a of the LD 21b, the scanning position H8 indicates a scanning position 2ΔTb before the emission stop at the second scanning position H2. The scanning position H10 indicates the scanning position before the division time ΔTb before the light emission stop at the second scanning position H2. In the forward scanning laser beam 300a, the scanning position H1 to H3 corresponds to the rising scanning range HB, and the scanning position H2 to H4 corresponds to the auxiliary light scanning range ΔHb.

  In the backward scanning laser light 300b of the LD 21b, the scanning position H7 indicates a scanning position 2ΔTb before the emission stop at the first scanning position H1. The scanning position H10 indicates the scanning position before the division time ΔTb before the light emission stop at the second scanning position H2. In the backward scanning laser beam 300b, the scanning position H2 to H4 corresponds to the rising scanning range HB, and the scanning position H1 to H3 corresponds to the auxiliary light scanning range ΔHb.

  The distance between the scanning positions H1 to H3 in the forward scanning laser light 300a and the distance between the scanning positions H2 to H4 in the backward scanning laser light 300b are the same HB. Further, between the scanning positions H2 to H10 in the forward scanning laser light 300a, between the scanning positions H8 to H10, and between the scanning positions H4 to H8, between the scanning positions H3 to H7 in the backward scanning laser light 300b, the scanning position. The distance in the X direction between H7 and H9 and between the scanning positions H1 and H9 is the same ΔHb.

  When the forward and backward scanning laser beams 300a and 300b are scanned, the amount of light between the scanning positions H1 and H2 is felt as shown in the graph of FIG. 23C by human vision. That is, between the scanning positions H1 to H3, the light quantity deficient in the rising scanning range HB of the forward scanning laser light 300a is uniformly compensated by the correction light quantities ΔPb1 to ΔPb3 in the supplementary scanning range ΔHb of the backward scanning laser light 300b. Is called. Further, between the scanning positions H2 to H4, the amount of light that is insufficient in the rising scanning range HB of the backward scanning laser light 300b is uniformly compensated by the correction light amounts ΔPb1 to ΔPb3 of the supplementary scanning range ΔHb of the outgoing scanning laser light 300a. Is called. Accordingly, the amount of light visually perceived by humans between the scanning positions H1 to H3 and between the scanning positions H2 to H4 can be brought close to the steady light amount Pb1 corresponding to the constant drive current Ib1. Therefore, it is possible to improve the decrease in light amount due to the light emission delay at the start of light emission of the LD 21b.

  Further, as described above, the light output of the red LD 21a and the blue LD 21c is similarly controlled. Therefore, by the light output control described above, the X-direction edge portion of the overlapping scanning range 301c where the forward and backward scanning laser beams 300a and 300b overlap, that is, the scanning range between the scanning positions H1 to H3 and the scanning positions H2 to H4. It is possible to reduce or prevent the color unevenness caused by the light emission delay of each of the LDs 21a to 21c in the scanning range.

  The correction light amounts ΔPb1 to ΔPb3 are divided into three stages in FIGS. 22 and 23A to 23C, but are not limited to this example, and may be divided into two or more stages. As the number of divisions increases, the number of processes increases, but color unevenness can be improved more uniformly and accurately.

<Seventh embodiment>
Next, a seventh embodiment will be described. In the seventh embodiment, before applying the drive currents of the current values Ia1, Ib1, and Ic1 corresponding to the steady light amounts Pa1 to Pc1 to the LDs 21a to 21c, the minute current values less than the oscillation threshold current Is of the LDs 21a to 21c. A preliminary current of Ip is applied. Below, a different structure from 4th-6th embodiment is demonstrated. Moreover, the same code | symbol is attached | subjected to the component similar to 1st-6th embodiment, and the description is abbreviate | omitted. In the following, the seventh embodiment will be described by taking the light output control of the red LD 21a as an example, but the light output control of the other LDs 21b and 21c can be similarly performed.

  First, the current-light output characteristics of the red semiconductor laser element 21a will be described. FIG. 24 is a graph showing the light output characteristics with respect to the drive current of the red LD 21a. As shown in FIG. 24, when the element temperature is 25 degrees, the red LD 21a shows the current-light output characteristic drawn by the solid line graph. The current value Is corresponding to the bending point of the solid line graph represents the oscillation threshold current Is of the red LD 21a. The oscillation threshold current Is is a current value indicating the lower limit of the current value that the red LD 21a emits only in the laser oscillation mode, and corresponds to the current value IB in FIG. That is, when a current value equal to or greater than the oscillation threshold current Is is applied, the red LD 21a outputs coherent light having a relatively uniform wavelength and phase by a stable laser oscillation operation. On the other hand, when a current value less than the oscillation threshold current Is is applied to the red LD 21a, the light emission mode changes and the wavelength and phase of the emitted light become uneven. However, if a current value Ip less than the oscillation threshold current Is is applied to the LD 21a before the drive current greater than the oscillation threshold current Is is applied to the LD 21a, the light emission delay is suppressed and the rise time TA is remarkably increased. . In the present embodiment, this phenomenon is used to improve the decrease in light amount due to the light emission delay at the start of light emission of the LD 21a to LD 21c. That is, in a predetermined period immediately after the start of emission of the scanning laser beams 300a and 300b in the scanning range as shown in FIG. 5 (application time Tp described later), a reserve current having a current value Ip less than the oscillation threshold current Is is supplied to the LDs 21a to 21c. Apply.

  The current value Ip does not have to be greatly separated from the oscillation threshold current Is, and may be a slightly small current value. Further, as shown in FIG. 24, the current-light output characteristics of the LD 21a change due to the element temperature and the deterioration of the element. Therefore, the current value Ip of the preliminary current is determined according to the current-light output characteristics (particularly the oscillation threshold current Is) corresponding to these conditions.

  FIG. 25 is a graph showing an example of the light output control of the red LD 21a in the seventh embodiment. FIG. 25 shows light output control of the red LD 21a from the start of light emission to the stop of light emission of the forward and backward scanning laser beams 300a and 300b. In FIG. 25, a time point ta9 is a time point after the application time Tp from the time point tS, and is a time point at which light of the light amount Pa1 is output from the LD 21a. Further, the time point ta10 is a time point before the light supplement time ΔTa (= Tp) from the time point tE, and is a time point when the light with the light amount Pa2 that is larger than the light amount Pa1 and the light amount Pa2 is output from the LD 21a.

  A preliminary current having a current value Ip is applied to the LD 21a during a predetermined period Tp between time points tS and ta9 immediately after the start of light emission. Further, the driving current having the current value Ia1 is applied between the time points ta9 and ta10, and the driving current having the current value Ia2 is applied between the time points ta3 and tE. The application time Tp for applying the preliminary current having the current value Ip to the LD 21a may be equal to or longer than the rise time TA of the LD 21a. If Tp ≧ TA, even if a drive current having a current value Ia1 (>> Ip) is applied to the LD 21a at time ta2, the light emission delay can be significantly suppressed or prevented. On the other hand, if Tp <TA, a light emission delay occurs at time ta2.

  Next, the apparent light quantity of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 felt by a person looking at the projection surface 102a when the light output control as shown in FIG. 25 is performed will be described. In the following, the apparent light amount of the red component of the scanning laser beam 300 will be described in the same manner as in FIG. 25, but it goes without saying that the apparent light amount of the other color components (that is, the green component and the blue component) can be similarly felt. It will be.

  FIGS. 26A to 26C are views for explaining the apparent light quantity of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 in the seventh embodiment. FIG. 26A is a diagram showing a change in light output of the forward scanning laser light 300a scanned from the first scanning position H1 to the second scanning position H2 in the seventh embodiment. FIG. 26B is a diagram showing a change in light output of the backward scanning laser light 300b scanned from the second scanning position H2 to the first scanning position H1 in the seventh embodiment. FIG. 26C is a diagram illustrating a change in the apparent light amount of the scanning laser light 300 between the first scanning position H1 and the second scanning position H2 in the seventh embodiment.

  It should be noted that in FIGS. 26A to 26C, the horizontal axis of the graphs indicates the position of the scanning laser beam 300 in the X direction, unlike FIG. Therefore, the optical output and drive current graph shape of FIG. 26A related to the forward scanning laser light 300a and the direction of the horizontal axis are reversed from those of FIG. 26B related to the backward scanning laser light 300b. FIG. 26C shows the apparent light quantity in the overlapping scanning range 301C (see FIG. 13) between the first scanning position H1 and the second scanning position H2 that the human senses due to the above-described effect of averaging the light quantity.

  The scanning position H11 is a scanning position after the application time Tp from the start of light emission at the first scanning position H1 in the forward scanning laser light 300a, and from the stop of light emission at the first scanning position H1 in the backward scanning laser light 300b. Is also a scanning position before the light supplement time ΔTa (= Tp). The scanning position H12 is a scanning position in the forward scanning laser light 300a before the light supplement time ΔTa before the light emission stop at the second scanning position H2, and the scanning laser light 300b in the backward path is at the second scanning position H2. This is also the scanning position after the application time Tp from the start of light emission. In the forward scanning laser beam 300a, the scanning position H1 to H11 corresponds to the scanning range at the application time Tp (hereinafter referred to as the application scanning range), and the scanning position H2 to H12 has the supplementary time ΔTa before the emission stop. This corresponds to the scanning range (that is, the auxiliary light scanning range ΔHp). In the backward scanning laser beam 300b, the scanning position between H2 and H12 corresponds to the applied scanning range at the application time Tp, and the scanning position between H1 and H11 falls within the supplementary scanning range ΔHp at the supplementary time ΔTa before light emission is stopped. It corresponds.

  In the forward and backward scanning laser beams 300a and 300b, the light amount Pa2 in the supplementary light scanning range ΔHp is larger than the light amount Pa1 corresponding to the drive current Ia1. Further, as described above, ΔTa = Tp. Therefore, the distance between the scanning positions H1 to H11 in the forward scanning laser light 300a and the distance between the scanning positions H2 to H12 in the backward scanning laser light 300b are the same Hp. The distances in the X direction between the scanning positions H2 to H12 in the forward scanning laser light 300a and the scanning positions H1 to H11 in the backward scanning laser light 300b are also the same Hp.

  When the forward and backward scanning laser beams 300a and 300b are scanned, the amount of light between the scanning positions H1 and H2 is felt as shown in the graph of FIG. 26C by human vision. That is, the amount of light that is insufficient in the applied scanning range of the forward scanning laser light 300a is compensated by the correction light amount ΔPa of the supplementary scanning range ΔHp of the backward scanning laser light 300b. Further, the amount of light that is insufficient in the applied scanning range of the backward scanning laser beam 300b is compensated by the correction amount ΔPa of the supplementary scanning range ΔHp of the outgoing scanning laser beam 300a. Therefore, the amount of light visually perceived by the human between the scanning positions H1 and H11 and between the scanning positions H2 and H12 can be brought close to the steady light amount Pa1 corresponding to the constant drive current Ia1, and the appearance between the scanning positions H1 and H3 is visible. It is also possible to set the amount of light to Pa1.

  In the present embodiment, the configuration in which the preliminary current having the current value Ip is applied at the application time Tp is applied to all the LDs 21a to 21c. However, the present invention is not limited to this example. This configuration may be applied to at least one of the plurality of LDs 21a to 21c (particularly, the red LD 21a having the longest rise time).

  Next, the light output control processing of the LDs 21a to 21c will be described. FIG. 27 is a flowchart for explaining an example of the light output control processing of the LDs 21a to 21c according to the seventh embodiment. The following S301 to S305 are performed during the retrace period, and S306 is performed during the trace period.

  First, in the retrace period, when the optical axis of the scanning laser beam 300 scans the invalid projection region 102c, the light output control unit 582 applies predetermined drive currents Ia1 to Ic1 to the LDs 21a to 21c, and LDs 21a to 21c. Is emitted with a predetermined amount of light (for example, Pa1, Pb1, Pc1) (S301). The application times of the drive currents Ia1 to Ic1 may be longer than the rise times TA, TB, and TC of the LDs 21a to 21c, respectively. The optical outputs of the LDs 21a to 21c are detected by the PDs 23a to 23c, respectively (S302). The calculation unit 583 calculates the rise times TA, TB, and TC of the LDs 21a to 21c based on the detection results of the PDs 23a to 23c (S303). Further, the calculation unit 583 sets a preliminary current application time Tp of the current value Ip to be applied to each of the LDs 21a to 21c based on the result of S303 (S304). In addition, the light output control unit 582 captures the video data output from the video processing unit 581 into a memory (not shown), and performs image analysis of a projection image projected on the combiner 102 during the trace period based on the video data. (S305). That is, the color information and luminance information of the projection image formed during the trace period are analyzed.

  Next, in the trace period, the light output control unit 582 uses the light output of the plurality of LDs 21 a to 21 c based on the image analysis result, the calculation result of the calculation unit 583, the light output correction information read from the storage unit 57, and the like. Output control is performed (S306).

<Summary of Fourth to Seventh Embodiments>
According to the fourth to seventh embodiments described above, the projector unit 101 includes the LD 21a to LD 21c that outputs the scanning laser light 300 having the light amounts Pa1, Pb1, and Pc1 (first light amount) and the projection surface 102a. A light output control including a MEMS engine unit 3 that reciprocally scans the scanning laser light 300 in a predetermined direction (for example, the X direction) with a range of directions, and a light output control unit 582 that controls the light output of the LDs 21a to LD21c. When the light amount of the scanning laser light 300 is suddenly reduced when the light emission is stopped, the unit 582 scans the scanning laser light 300 between the start of light emission and the stop of light emission. 301a and 301b (first scanning range) The second light amount (Pa2, Pb4-6, etc.) in the supplementary light scanning range ΔHa (second scanning range) immediately before the light emission stop position is set to the light amounts Pa1, Pb1, Pc. It is configured to be larger than. (30th configuration)

  According to the thirtieth configuration, in the scanning laser beam 300 that is reciprocally scanned on the projection surface 102a, when the light amount of the scanning laser beam 300 is suddenly reduced when the emission is stopped, from the start of emission to the stop of emission. Among the scanning ranges 301a and 301b (first scanning range) in which the scanning laser beam 300 is scanned in between, the light amounts Pa2, Pb4 to 6 in the auxiliary light scanning range ΔHa (second scanning range) immediately before the light emission stop position (first) 2 light quantity) is made larger than the light quantities Pa1, Pb1, Pc1 (first light quantity). Here, since the scanning laser beam 300 is reciprocally scanned, when the light amount of the scanning laser beam 300 is suddenly reduced when light emission is stopped, the light amount of the scanning laser beam 300 is usually abruptly increased at the start of light emission. As a result, the amount of light is reduced (so-called rounding) due to the light emission delay. On the other hand, according to the above configuration, the amount of light that is lower than the amount of light Pa1, Pb1, and Pc1 due to the light emission delay at the start of light emission in the scanning laser light 300a or 300b of one of the forward path and the backward path is scanned by the other. It can be supplemented by the light amount Pa2, Pb4-6, etc. (second light amount) in the supplementary light scanning range ΔHa immediately before the emission stop position of the laser light 300b or 300a. Accordingly, it is possible to reduce a reduction in the amount of light of the scanning laser beam 300 that is visually perceived by humans. Therefore, it is possible to improve the decrease in the amount of light caused by the light emission delay at the start of light emission of the LDs 21a to 21c.

  The projector unit 101 having the thirtieth configuration further includes a memory (not shown) for storing image information (video data) formed on the projection surface 102a, and the light output control unit 582 analyzes the image information. The optical output may be controlled based on the result of the analysis. (31st configuration)

  According to the thirty-first configuration, the light outputs of the LDs 21a to 21c can be controlled based on the analysis result of the image information formed on the projection surface 102a.

  In the projector unit 101 having the above-described configuration of the thirty-first or thirty-second configuration, the light output control unit 582 has a rise time TA from the start of light emission to the light output of the light amounts Pa1, Pb1, and Pc1 (first light amount). In the case where the fall time from the start of the decrease of the light amount of the scanning laser light 300 to the stop of light emission is shorter than the light amount Pa2, Pb4-6, etc. (second light amount) may be made larger than the light amounts Pa1, Pb1, Pc1. . (33rd configuration)

  According to the thirty-third configuration, when the fall time at the stop of light emission is shorter than the rise time TA at the start of light emission, the light amount of the scanning laser light 300a or 300b is rapidly reduced when the light emission is stopped. Yes. For this reason, normally, when the next scanning laser beam 300b or 300a starts to emit light, a light amount decrease due to the light emission delay occurs. This light amount decrease is caused by the light amount Pa2, Pb4 to 6 and the like (second light amount). Can be supplemented.

  In the projector unit 101 having any one of the thirtieth to thirty-third configurations, the light output control unit 582 scans the light emission start position and the light emission stop position of the scanning range 301a with the forward scanning laser light 300a, respectively. The laser light 300b may be configured to correspond to the light emission stop position and the light emission start position of the scanning range 301b. (34th configuration)

  According to the thirty-fourth configuration, the light amount is lower than the light amounts Pa1, Pb1, and Pc1 (first light amount) due to the light emission delay at the start of light emission in the scanning laser light 300a or 300b of one of the forward path and the backward path. The second light amount (Pa2, Pb4-6, etc.) of the other scanning laser light 300b or 300a can be more reliably supplemented.

  In the projector unit 101 having the above-described thirty-fourth configuration, in a predetermined direction having a direction range (for example, the X direction), the supplementary light scanning range ΔHa in the forward scanning laser light 300a starts to be emitted in the backward scanning laser light 300b. It is also possible to have an arrangement that overlaps with the rising scanning ranges HA and HB (third scanning range) in which the scanning laser light 300b in the backward path is scanned until the light output of the light amounts Pa1, Pb1, and Pc1 (first light amount) is reached. Good. Further, the complementary light scanning range ΔHa with the backward scanning laser light 300b is scanned by the forward scanning laser light 300a from the start of light emission until the light output of the light amounts Pa1, Pb1, and Pc1 is reached in the forward scanning laser light 300a. It is good also as a structure which overlaps with the starting scanning range HA and HB. (35th configuration)

  According to the thirty-fifth configuration, the auxiliary light scanning range ΔHa can be overlapped with the rising scanning ranges HA and HB. Note that the light amount of the scanning laser light 300 is larger than the light amounts Pa1, Pb1, and Pc1 (first light amounts) in the auxiliary light scanning range ΔHa, and the scanning laser light 300 is caused in the rising scanning ranges HA and HB due to the light emission delay. Is lower than the light amounts Pa1, Pb1, and Pc1. Accordingly, it is possible to reliably project the scanning laser beam 300 having a light amount larger than the light amounts Pa1, Pb1, and Pc1 to the rising scanning ranges HA and HB.

  In the projector unit 101 having the thirty-fourth or thirty-fifth configuration, in a predetermined direction having a direction range (for example, the X direction), the scanning distance in the supplementary scanning range ΔHa with the forward scanning laser light 300a is A configuration in which the scanning laser beam 300b is equal to or shorter than the scanning distance in the rising scanning ranges HA and HB may be employed. Further, the scanning distance in the supplementary scanning range ΔHa with the backward scanning laser light 300b may be equal to or shorter than the scanning distances in the rising scanning ranges HA and HB of the outgoing scanning laser light 300a. (Thirty-sixth configuration)

  According to the thirty-sixth configuration, among the scanning ranges 301a and 301b, the light amounts Pa1, Pb1, and Pc1 (first light amount) are present in the scanning ranges other than the rising scanning ranges HA and HB in which the light amount decreases due to the light emission delay. It is possible to prevent the scanning laser light 300 having a larger light amount Pa2, Pb4 to 6 (second light amount) from being projected.

  In the projector unit 101 having any one of the 34th to 36th configurations, the light output control unit 582 outputs the accumulated light amounts S2 and s2 in the supplementary light scanning range ΔHa in the forward and backward scanning laser beams 300a and 300b. It may be configured to be the same as the cumulative amount S1 and s1 of the light amount reduced due to the light emission delay of the LDs 21a to 21c. (37th configuration)

  According to the thirty-seventh configuration, the accumulated light amount S1 and s1 reduced due to the light emission delay is complemented by the accumulated light amounts S2 and s2 in the supplementary light scanning range ΔHa, whereby the light emission delay that a human can visually perceive. It is possible to more effectively improve or eliminate the decrease in the light amount of the scanning laser beams 300a and 300b due to the above.

  The projector unit 101 having any one of the thirtieth to thirty-seventh configurations further includes an LD driver 52 that supplies a driving current to the LDs 21a to 21c. The LDs 21a to 21c are semiconductor laser elements, and the LD driver 52 includes: When the light amount of the scanning laser beam 300 is suddenly decreased when the light emission is stopped, the oscillation threshold value from the first current value equal to or higher than the oscillation threshold current Is indicating the lower limit of the current value emitted by the LD 21a to 21c only in the laser oscillation mode. The drive current may be reduced to a second current value less than the current Is. (38th configuration)

  According to the thirty-eighth configuration, the amount of the scanning laser light 300 emitted from the LDs 21a to 21c that emit light only in the laser oscillation mode can be sharply reduced.

  In the projector unit 101 having any one of the thirtieth to thirty-eighth configurations, the light output controller 582 divides the light amounts Pb4 to Pb6 (see, for example, FIG. 22) in the auxiliary light scanning range ΔHa into a plurality of stages. It is good also as a structure to increase. (39th configuration)

  According to the thirty-ninth configuration, the scanning laser light 300 can be projected according to the distribution of the amount of light reduced due to the light emission delay. Accordingly, it is possible to more uniformly improve the reduction in the amount of light caused by the light emission delay at the start of light emission of the LDs 21a to 21c.

  In the projector unit 101 having any one of the thirtieth to thirty-ninth configurations, the LDs 21a to 21c are semiconductor laser elements, and immediately after the start of the emission of the scanning laser beams 300a and 300b in the first scanning ranges 301a and 301b. In the predetermined period Tp, a reserve current having a current value Ip less than the oscillation threshold current Is indicating the lower limit of the current value emitted by the LDs 21a to 21c only in the laser oscillation mode may be applied to the LDs 21a to 21c. (40th configuration)

  According to the fortieth configuration, by applying a preliminary current having a current value Ip less than the oscillation threshold current Is to the LDs 21a to 21c in advance, the light emission delay of the LDs 21a to 21c can be suppressed or prevented.

  Further, in the projector unit 101 having the above-described configuration of the fortieth configuration, the application time Tp of the preliminary current (current value Ip) is set to light amounts Pa1, Pb1, and Pc1 (first light amount) after the LDs 21a to 21c start to emit light. A configuration may be employed in which the rise times TA, TB, and TC required for reaching the optical output are equal to or longer. (41st configuration)

  According to the forty-first configuration, the application time Tp of the preliminary current having the current value Ip is set to the rise times TA, TB, and TC or more, so that the light emission delay of the LDs 21a to 21c can be prevented.

  According to the fourth to seventh embodiments, the projector unit 101 controls the LD 21 a to 21 c that emits the laser beam 300, the MEMS engine unit 3 that scans the laser beam 300, and the light quantity of the LD 21 a to 21 c. An optical output control unit 582. The optical output control unit 582 starts and stops the light emission of the LDs 21a to 21c in the forward path and the return path, and starts the light emission of at least one of the LDs 21a to 21c in the forward path and the return path. The scanning range until the stop is the rising scanning range HA (first scanning range) from when the light emission starts until the light amount becomes the first light amount Pa1, Pb1, Pc1, and the light amount is the first light amount. Between the forward paths H3 to H6 and between the backward paths H4 to H5 (second scanning range) scanned with the light quantities Pa1, Pb1, and Pc1, the light quantity is the first light quantity Pa1, a supplementary light scanning range ΔHa (third scanning range) from when the second light quantity (Pa2, Pb4 to 6 etc.) is larger than b1 and Pc1 until the light emission is stopped, and the supplementary light scanning range The length of ΔHa is configured to be equal to or shorter than the length of the rising scanning range HA. (Forty-second configuration)

  The projector unit 101 having the forty-second configuration further includes a storage unit 57 for storing image information of the projection image, and the light output control unit 582 analyzes the image information and based on the result of the analysis. Thus, the amount of light is controlled. (43rd configuration)

  In the projector unit 101 having the forty-second or forty-third configuration, the light emission start position and the light emission stop position in the forward rising scanning range HA are the light emission stop position and the light emission start in the auxiliary light scanning range ΔHa on the return path, respectively. The configuration corresponds to the position. (44th configuration)

  Further, the projector unit 101 having the forty-fourth configuration is configured such that the rising scanning range HA of the laser beam 300a in the forward path overlaps with the supplementary scanning range ΔHa of the laser beam 300b in the backward path. (45th configuration)

  In the projector unit 101 having the forty-fourth or forty-fifth configuration, the length of the supplementary scanning range ΔHa of the laser light 300a in the forward path is the length of the rising scanning range HA of the laser light 300b in the backward path. It is set as the following structures. (46th configuration)

  In the projector unit 101 having the above-described 44th to 46th configurations, the light output control unit 582 has the cumulative light amount in the supplementary light scanning range ΔHa of the at least one laser light 300 as the at least one of the above-mentioned. The accumulated amount of the light amount reduced due to the light emission delay of the light emitting element that outputs the laser light 300 is set to be the same. (47th configuration)

  The projector unit 101 of the forty-seventh configuration further includes an LD driver 52 that supplies a driving current to a light emitting element that outputs the laser light 300, and the light emitting element is a semiconductor laser element, and the LD driver 52 From the first current value equal to or higher than the oscillation threshold current Is indicating the lower limit of the current value that the semiconductor laser element emits only in the laser oscillation mode in the complementary light scanning range ΔHa with the at least one laser beam 300 The drive current is reduced to a second current value less than the oscillation threshold current Is. (Forty-eighth configuration)

  In the projector unit 101 having the 47th or 48th configuration, the light emitting element is a semiconductor laser element, and a predetermined period Tp after the emission of the laser beam 300 in the rising scanning range HA is started. The semiconductor laser device is configured such that a preliminary current having a current value Ip less than an oscillation threshold current Is indicating a lower limit of a current value emitted only in the laser oscillation mode is applied to the semiconductor laser device. (49th configuration)

  In the projector unit 101 of the forty-ninth configuration, the application time Tp of the preliminary current (current value Ip) is from the start of light emission of the semiconductor laser element until the light amount reaches the first light amounts Pa1, Pb1, and Pc1. It is set as the structure which is more than time TA, TB, TC which it takes. (50th configuration)

  Further, in the projector unit 101 having the forty-second to fifty-th configuration, the light output control unit 582 divides the second light amount (Pa2, Pb4-6, etc.) in the auxiliary light scanning range ΔHa into a plurality of stages. It is set to increase. (51st configuration)

  The embodiment of the present invention has been described above. Note that the above-described embodiment is an exemplification, and various modifications can be made to each component and combination of processes, and it will be understood by those skilled in the art that they are within the scope of the present invention.

  For example, in the first to seventh embodiments described above, some or all of the components 581 to 583 included in the CPU 58 may be functional components, or may be a physical circuit such as an electric circuit, apparatus, or device. It may be a component. In addition, at least some of the components 581 to 583 may be components independent of the CPU 58.

  In the first to seventh embodiments described above, the laser projector 101 of the HUD device 100 is described as an example, but the scope of application of the present invention is not limited to these examples. The present invention can be widely applied as long as it is a device that performs light output control of a plurality of light sources having different emission wavelengths.

100 Head-up display device (HUD device)
DESCRIPTION OF SYMBOLS 101 Projector unit 102 Combiner 200 Vehicle 201 Windshield 300 Scanning laser beam 400 User's line of sight 1 Housing 1a Window 2 Optical engine part 21a-21c Laser diode (LD)
22 Optical system 221a-221c Collimator lens 222a-222c Beam splitter 223 Condensing lens 23a-23c Photo detector (PD)
DESCRIPTION OF SYMBOLS 3 MEMS engine part 31 MEMS mirror 50 Main body housing | casing 50a Light exit 51 MEMS mirror driver 52 LD driver 53 Power supply 54 Power supply control part 55 Operation part 56 Input / output I / F
57 Memory 58 CPU
581 Video processing unit 582 Light output control unit 583 Calculation unit

Claims (10)

A plurality of light sources for emitting laser light;
A scanning unit that scans the laser beam;
A control unit for controlling the output of the laser beam,
The control unit performs control such that the output is a first light amount in the first scanning range in a scanning range including a first scanning range and a second scanning range, and the output is the first light amount in the second scanning range. A projection device that performs control to obtain a second light amount that is greater than one light amount. A memory for storing image information of an image to be projected onto the projection plane;
The projection device according to claim 1, wherein the control unit controls an output of the laser light based on the image information.   The control unit is configured such that the time from when the laser beam starts to be emitted until the output reaches the first light amount is shorter than the time from when the output starts to decrease from the first light amount until the laser beam emission is stopped. And controlling the output to be a first light amount in the first scan range and controlling the output to be a second light amount greater than the first light amount in the second scan range. The projection device according to claim 1 or 2. The scanning unit scans the laser beam back and forth,
The emission start position and the emission stop position of the laser beam in the first scanning range of the forward path correspond to the emission stop position and the emission start position of the laser beam in the first scanning range of the return path, respectively. The projection device according to claim 3.   The second scanning range in the forward path overlaps with a third scanning range in which the laser light in the backward path is scanned from the start of emission in the backward path until the output reaches the first light amount. 4. The projection device according to 4. The plurality of light sources include a first light source and a second light source, and the time required for the first light source to output a predetermined amount of light is longer than that of the second light source,
The projection apparatus according to claim 1, wherein the control unit performs control to supply a driving current to the first light source before the second light source.   The control unit is configured to determine a light amount of the first light source and a light amount of the second light source based on a time difference of each time from the start of emission of the laser light to the output reaching the first light amount in the plurality of light sources. The projection device according to claim 6, wherein control is performed such that each time point at which the predetermined ratio is reached is the same with respect to the predetermined light amount.   The control unit supplies a driving current having a first current value that causes a light output less than the predetermined light amount to the second light source, and then supplies a driving current having a second current value that causes the light output having the predetermined light amount. The projection apparatus of Claim 6 or Claim 7 supplied to a 2nd light source.   The projection device according to any one of claims 6 to 8, wherein the control unit increases the driving current of the second light source in a plurality of stages up to a current value for outputting the predetermined amount of light.   10. The calculation unit according to claim 6, further comprising: a calculation unit that calculates the time of each of the plurality of light sources based on a detection result of a light detection unit that detects a light amount of each of the plurality of light sources. Projection device.

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