JP6813785B2 - Optical scanning controller - Google Patents

Description

The present invention relates to an optical scanning control device.

An optical scanning control device that scans a laser beam and displays an image is known. This optical scanning control device includes a first detection means that directly detects the light emitted from the light source without going through the optical system, and a second detection means that detects the light emitted from the light source through the optical system. .. Then, the power of the laser beam can be adjusted based on the detection result of the first detection means or the second detection means (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-11852

However, when trying to widen the brightness adjustment range of the optical scanning control device, it may not be possible to reach the desired brightness only by adjusting the amount of light emitted by the laser. Therefore, a method is being studied in which a dimming means is arranged on the optical path leading to the screen, the light incident on the dimming means is dimmed and transmitted, and the brightness on the screen can be adjusted to an appropriate value.

However, in the above method, unnecessary light reflected by the dimming means may be generated, and this unnecessary light is further reflected by surrounding structures and the like to reach the screen and reduce the contrast of the image to be drawn. There was a risk.

The present invention has been made in view of the above points, and an object of the present invention is to provide an optical scanning control device capable of attenuating unnecessary light reflected by a dimming means.

The optical scanning control device (1) dims the light emitted from the lasers (211R, 211G, 211B) and transmits the light, and the light transmitted through the dimming means (24). A scanning means (310) that scans two dimensions in the horizontal and vertical directions according to a video signal to form an image on the screen (50), and a first that detects the amount of light before passing through the dimming means (24). A transparent member arranged on an optical path between the light amount detecting means (215), the dimming means (24), and the scanning means (310) and forming a part of a member for sealing the scanning means (310). The second light amount detecting means (60) includes a plate (400) and a second light amount detecting means (60) for detecting the amount of light after passing through the dimming means (24). It is a requirement to detect the amount of reflected light reflected by the transparent plate (400).

The reference numerals in the parentheses are provided for easy understanding, and are merely examples, and are not limited to the illustrated modes.

According to the disclosed technique, it is possible to provide an optical scanning control device capable of attenuating unnecessary light reflected by the dimming means.

It is a block diagram which illustrates the optical scanning control apparatus which concerns on this embodiment. It is a top view which illustrates the optical scanning part which constitutes the optical scanning control apparatus. It is an external view (the 1) which illustrates the optical scanning control apparatus which concerns on this embodiment. FIG. 2 is an external view (No. 2) illustrating the optical scanning control device according to the present embodiment. It is sectional drawing which illustrates the antireflection structure of the dimming filter which concerns on this embodiment. It is a perspective view which illustrates the antireflection structure of the dimming filter which concerns on this embodiment. It is a figure explaining the installation direction of the antireflection structure. It is a figure (the 1) explaining another example of a dimming filter. It is a figure (the 2) explaining another example of a dimming filter. It is a figure explaining the monitor of the reflected light of a cover glass.

Hereinafter, modes for carrying out the invention will be described with reference to the drawings. In each drawing, the same components may be designated by the same reference numerals and duplicate description may be omitted.

FIG. 1 is a block diagram illustrating an optical scanning control device according to the present embodiment. FIG. 2 is a plan view illustrating an optical scanning unit constituting the optical scanning control device. 3 and 4 are external views illustrating the optical scanning control device according to the present embodiment.

(Rough configuration of optical scanning control device)
First, a schematic configuration of the optical scanning control device 1 will be described with reference to FIGS. 1 to 4. The optical scanning control device 1 has a circuit unit 10, a light source unit 20, an optical scanning unit 30, an optical unit 40, a screen 50, and a light amount detection sensor 60 as main components, and these are housings. It is stored in the body 100. The optical scanning control device 1 is, for example, a laser scanning projector.

The circuit unit 10 is a unit that controls the light source unit 20 and the optical scanning unit 30, and can be configured by, for example, a system controller 11, a CPU (Central Processing Unit) 12, various drive circuits, and the like.

The light source unit 20 includes an LD module 21, a temperature control unit 22, a temperature sensor 23, and a dimming filter 24.

The LD module 21 includes lasers 211R, 211G, and 211B, which change the amount of light emitted according to the current value, and a light amount detection sensor 215, which monitors the latest light amount of each of the lasers 211R, 211G, and 211B. .. The laser 211R is, for example, a red semiconductor laser and can emit light having a wavelength of λR (for example, 640 nm). The laser 211G is, for example, a green semiconductor laser and can emit light having a wavelength of λG (for example, 530 nm). The laser 211B is, for example, a blue semiconductor laser and can emit light having a wavelength of λB (for example, 445 nm). As the light amount detection sensor 215, for example, a photodiode or the like can be used. The light amount detection sensor 215 can be arranged at an arbitrary position where the light amount before passing through the dimming filter 24 can be detected.

The temperature control unit 22 can control the lasers 211R, 211G, and 211B to a predetermined temperature. The temperature sensor 23 can detect the temperatures of the lasers 211R, 211G, and 211B, respectively. As the temperature control unit 22, for example, a Peltier element can be used. As the temperature sensor 23, for example, a thermistor can be used.

The dimming filter 24 is arranged in front of the mirror 310, and the light (light after synthesis) emitted from the lasers 211R, 211G, and 211B is incident. The dimming filter 24 has a function of dimming and transmitting incident light and adjusting the brightness on the screen 50. As the neutral density filter 24, an ND (Neutral Density) filter, a liquid crystal element, a polarizing filter, or the like can be used. The dimming filter 24 is arranged at an angle with respect to the optical axis of the incident light, and the light that is not transmitted (light that is dimmed) is absorbed or reflected by the dimming filter 24. The dimming filter 24 is a typical example of the dimming means according to the present invention.

The optical scanning unit 30 is, for example, a MEMS (Micro Electro Mechanical System) that drives the mirror 310 by a piezoelectric element. The mirror 310 reflects the light (combined light) emitted from the lasers 211R, 211G, and 211B, scans the incident light in two dimensions in the horizontal and vertical directions according to the video signal, and connects the light to the screen 50. It functions as a scanning means for imaging.

Specifically, as shown in FIG. 2, the mirror 310 is supported from both sides by the twisted beams 331 and 332 forming the shaft. Drive beams 351 and 352 are provided in pairs so as to sandwich the mirror 310 in the direction orthogonal to the twisted beams 331 and 332. Piezoelectric elements formed on the surfaces of the drive beams 351 and 352 can swing the mirror 310 around the twisted beams 331 and 332 as axes. The direction in which the mirror 310 swings around the axes of the twisted beams 331 and 332 is hereinafter referred to as the horizontal direction. For example, resonance vibration is used for horizontal driving by the driving beams 351 and 352, and the mirror 310 can be driven at high speed. The horizontal displacement sensor 391 is a sensor that detects the degree of inclination of the mirror 310 in the horizontal direction when the mirror 310 is swinging in the horizontal direction.

Further, on the outside of the drive beams 351 and 352, drive beams 371 and 372 are provided in pairs. The piezoelectric elements formed on the surfaces of the drive beams 371 and 372 can swing the mirror 310 in the vertical direction, which is a direction orthogonal to the horizontal direction. The vertical displacement sensors 395 and 396 are sensors that detect the degree of inclination of the mirror 310 in the vertical direction when the mirror 310 is swinging in the vertical direction. The optical scanning unit 30 is mounted on a ceramic package together with a drive circuit and the like in the unit 150 (see FIG. 3B), and is covered with a ceramic cover, for example.

The optical unit 40 is an optical system for projecting the light scanned by the optical scanning unit 30 onto the screen 50. For example, as shown in FIG. 3B, the reflection mirror 41, the reflection mirror 42, and the reflection are reflected. It can be configured to include a mirror 43, a concave mirror 44, and the like. However, if necessary, a lens may be used instead of the reflection mirror. The light incident on the optical unit 40 from the optical scanning unit 30 is regarded as substantially parallel light by the concave mirror 44 and imaged on the screen 50, and an image corresponding to the video signal is drawn on the screen 50.

The screen 50 includes, for example, a microlens array in order to remove noise of a grainy image called speckle. In this case, each microlens constituting the microlens array corresponds to a pixel of the display, and it is desirable that the irradiated laser beam is equal to or smaller than the size of the microlens.

The light amount detection sensor 60 is arranged at a position where the light amount after passing through the dimming filter 24 can be detected. The light amount detection sensor 60 can independently detect the light amount of each of the lasers 211R, 211G, and 211B after passing through the dimming filter 24. As the light amount detection sensor 60, for example, one or a plurality of photodiodes can be used. The light amount detection sensor 60 is a typical example of the light amount detection means according to the present invention.

(Approximate operation of optical scanning control device)
Next, the schematic operation of the optical scanning control device 1 will be described. The system controller 11 can control the runout angle of the mirror 310, for example. The system controller 11 monitors, for example, the horizontal and vertical tilts of the mirror 310 obtained by the horizontal displacement sensors 391, the vertical displacement sensors 395 and 396 via the buffer circuit 13, and sends an angle control signal to the mirror drive circuit 14. Can be supplied. Then, the mirror drive circuit 14 supplies a predetermined drive signal to the drive beams 351 and 352 and the drive beams 371 and 372 based on the angle control signal from the system controller 11, and drives (scans) the mirror 310 at a predetermined angle. can do.

Further, the system controller 11 can supply, for example, a digital video signal to the laser drive circuit 15. Then, the laser drive circuit 15 supplies a predetermined current to the lasers 211R, 211G, and 211B based on the video signal from the system controller 11. As a result, the lasers 211R, 211G, and 211B emit red, green, and blue light modulated according to the video signal, and these can be combined to form a color image.

For example, the CPU 12 can monitor the amount of emitted light at the bases of the lasers 211R, 211G, and 211B by the output of the light amount detection sensor 215, and can supply the light amount control signal to the LD module 21. The lasers 211R, 211G, and 211B are current-controlled so as to have a predetermined output (light intensity) based on the light intensity control signal from the CPU 12.

The light amount detection sensor 215 can be configured to include three sensors that independently detect the emitted light amount of the lasers 211R, 211G, and 211B. Alternatively, the light amount detection sensor 215 may be composed of only one sensor. In this case, the amount of emitted light of the lasers 211R, 211G, and 211B can be controlled by sequentially emitting the lasers 211R, 211G, and 211B and sequentially detecting them with one sensor.

Further, the CPU 12 can monitor the temperatures of the lasers 211R, 211G, and 211B by the output of the temperature sensor 23, and can supply the temperature control signal to the temperature control circuit 16. Then, the temperature control circuit 16 supplies a predetermined current to the temperature control unit 22 based on the temperature control signal from the CPU 12. As a result, the temperature control unit 22 is heated or cooled, and each laser can be controlled to reach a predetermined temperature.

The light amount detection sensor 60 detects the amount of light after passing through the dimming filter 24. As described above, the light amount detection sensor 215 for performing the light amount adjustment of each laser is mounted in the LD module 21, and the roots of the lasers 211R, 211G, and 211B (before passing through the dimming filter 24). ) The amount of emitted light is detected. However, since the image actually displayed by the optical scanning control device 1 is based on the light formed on the screen 50, it may not be possible to make a correct adjustment by adjusting the amount of laser light at the base.

For example, since the dimming filter 24 is provided on the optical path, the expected dimming ratio cannot be obtained depending on the characteristics of the dimming filter 24. Therefore, the amount of light after passing through the dimming filter 24 is as expected. It may not be. Further, when the dimming ratio of each of the R / G / B of the dimming filter 24 varies, the white balance after passing through the dimming filter 24 may be lost. In addition, the characteristics of the optical scanning unit 30 may fluctuate due to temperature and deterioration over time. Such a problem cannot be solved no matter how precisely the light amount before passing through the light scanning unit 30 is controlled by the light amount detection sensor 215.

Therefore, the optical scanning control device 1 is provided with a light amount detection sensor 60 as a light amount detecting means for detecting the amount of light after passing through the dimming filter 24. The detection result of the light amount detection sensor 60 is input to the CPU 12 which is a control means, and the CPU 12 supplies the LD module 21 with a light amount control signal for controlling the current value of each laser based on the light amount detected by the light amount detection sensor 60. Can be done.

As a result, the amount of laser light including fluctuations in the characteristics of the dimming filter 24 can be detected, so that it is possible to perform accurate light amount control corresponding to the image actually displayed on the screen 50. The light amount detection sensor 60 can independently detect the light amounts of the lasers 211R, 211G, and 211B, and the CPU 12 determines the current value of each laser based on the light amount detected by the light amount detection sensor 60. Can be controlled.

(Anti-reflection structure of dimming filter)
The light component that is dimmed by the dimming filter 24 and becomes unnecessary is absorbed or reflected, but it is impossible to completely eliminate the reflected light. Therefore, if the reflected light (stray light) is not properly processed, the reflected light may be further reflected by the surrounding structures and reach the screen 50, which may reduce the contrast of the image to be drawn.

As a countermeasure, a method of increasing the light absorption rate of the dimming filter 24 and lowering the reflectance and absorbing the light by the dimming filter 24 itself can be considered. However, the focused laser light before it enters the mirror 310 has a high energy density of light, and may be converted into heat to cause deterioration of the filter film constituting the dimming filter 24.

Further, from the viewpoint of reducing the energy density of light, there is also a method of inserting an absorption type dimming filter into the spread light after scanning with the mirror 310. However, in this case, the incident light on the dimming filter becomes diffused light, and the incident angle range becomes wide. Therefore, it is difficult to make the dimming rate of the dimming filter uniform regardless of the incident angle.

In the present embodiment, in order to solve such a problem, a reflection type dimming filter 24 in which the filter film does not deteriorate is used, and reflection for simply absorbing light so as not to generate stray light. A prevention structure 70 is provided. Hereinafter, the antireflection structure 70 will be described in detail.

FIG. 5 is a cross-sectional view illustrating the antireflection structure of the dimming filter according to the present embodiment, and shows a cross section in the vicinity of the dimming filter. Further, FIG. 6 is a perspective view illustrating the antireflection structure of the dimming filter according to the present embodiment, and shows the vicinity of the dimming filter.

As shown in FIGS. 5 and 6, the laser light L emitted from the outlet 219 of the LD module 21 reaches the dimming filter 24 and is separated into the transmitted light L ₁ and the reflected light L ₂ . The transmitted light L ₁ passes through the dustproof cover glass 400 and heads toward the mirror 310, and finally becomes an image drawn on the screen 50, but the reflected light L ₂ is dimmed unnecessary light. It is the role of the antireflection structure 70 to attenuate the reflected light L _2, which is unnecessary light, so as not to go toward the mirror 310 again.

The antireflection structure 70 combines two plates 710 and 720 whose inner surface is a smooth surface having low reflectance in a wedge shape (V shape), and reflects light L in the apical direction in which the plates 710 and 720 contact. ₂ is incident. In other words, the anti-reflection structure 70, the reflected light L ₂ is arranged to meet the top edges in contact with each other of the plate 710 and 720. It is preferable that the smooth surfaces of the plates 710 and 720 are surfaces having low reflectance and low surface roughness (small scattering).

As the plates 710 and 720, for example, absorbent glass, glass with an absorbent film, or a metal material subjected to black treatment (anodizing, plating, etc.) can be used. However, it may be a resin as the plate 710 and 720, since the plates 710 and 720 are heated by the reflected light L _2, it is preferable to use a glass or metal material having high heat resistance than the resin. In FIG. 6, for convenience, the plates 710 and 720 are drawn transparently (the same applies to FIG. 7 described later).

At the entrance of the anti-reflection structure 70, a plate 730 that reflected light L ₂ is equipped with entrance 730x are holes that passes is provided in contact with one side of the plate 710 and 720. Further, two plates (not shown in FIGS. 5 and 6) are installed, which form side surfaces so as to close the triangular openings formed by the plates 710, 720, and 730. That is, the antireflection structure 70 is hermetically sealed except for the incident port 730x, and it is the incident port 730x that allows light to enter the inside of the antireflection structure 70 or to be emitted to the outside from the inside of the antireflection structure 70. Only when going through.

The antireflection structure 70 is held by the holding structure 410. Since the plate 710 and 720 of the anti-reflection structure 70 is heated by the reflected light L _2, the retention structure 410 is preferably formed by a thermally enhanced metal.

The reflected light L ₂ incident on the inside of the antireflection structure 70 from the incident port 730x is absorbed by the smooth surface while being multiple-reflected between the smooth surfaces of the plates 710 and 720, so that it is unnecessary to come out from the incident port 730x. There is very little light. That is, by providing the antireflection structure 70 and taking the reflected light L ₂ generated by the dimming filter 24 into the antireflection structure 70 and sufficiently attenuating it, unnecessary light reaches the screen 50 and is drawn. The risk of reducing the contrast of the light can be reduced.

The proportion of light absorbed by the smooth surfaces of the plates 710 and 720 differs depending on the polarization direction of the light incident on the smooth surfaces, and the polarization direction of the reflected light L ₂ is P-polarized light with respect to the smooth surfaces of the plates 710 and 720. When a large amount of components are incident, the proportion of light absorbed by the smooth surface increases. FIG. 7 shows a case where the installation directions of the smooth surfaces of the plates 710 and 720 are rotated by 90 ° with respect to FIG. By selecting the installation direction of either FIG. 6 or FIG. 7 so that the polarization direction of the reflected light L ₂ is such that a large amount of the P polarization component is incident on the smooth surfaces of the plates 710 and 720, the reflected light L ₂ is absorbed by the smooth surface. The ratio of light can be increased, and unnecessary light emitted from the incident port 730x can be further reduced.

As described above, the antireflection structure 70 is provided inside with two smooth surfaces in which the top surfaces are in contact with each other to form a V shape, and is sealed except for the incident port 730x provided on the opening side of the V shape. .. Then, the reflected light L ₂ is incident on the inside of the antireflection structure 70 from the incident port 730x, is reflected multiple times between the two smooth surfaces, is absorbed by the two smooth surfaces, and is attenuated.

(Other examples of dimming filters)
The dimming filter 24 may be composed of one filter as shown in FIGS. 5 to 7, but as shown in FIGS. 8 and 9, a plurality of dimming filters having different transmittances are slid. It may be configured to be replaced. As a result, the light can be dimmed to the required amount by selecting the dimming filter according to the specifications.

In the examples of FIGS. 8 and 9, the dimming filter 24 has eight dimming filters having different transmittances, and these are held in the holder 420. A pair of shafts 430 parallel to each other are inserted through the holder 420, and the pair of shafts 430 are held by a pair of shaft holding portions 440 provided on both sides.

The dimming filter 24 held in the holder 420 is configured to be movable in the direction of the arrow along the pair of shafts 430, and one dimming filter according to the specifications is selected from eight different dimming filters. it can. The dimming filter 24 can be moved by, for example, a stepping motor (not shown).

It is preferable that at least one of the eight dimming filters is a transparent plate having no dimming function. This is because by providing a transparent plate, it is possible to meet specifications that do not dimming. Also, when light is transmitted through the dimming filter inserted at an angle, the optical axis shift occurs due to the refractive index of the material of the dimming filter, so the amount of light shift is equal regardless of which dimming filter is selected. Is desirable. By providing the transparent plate, even in the case of the specification that does not dimming, the light passes through the transparent plate, so that the shift amount can be the same as when the dimming filter is selected.

Although the example in which the dimming filter 24 includes a plurality of dimming filters having different transmittances has been shown above, a liquid crystal element may be used as the dimming filter 24. When a liquid crystal element is used as the dimming filter 24, the transmittance can be changed by controlling the applied voltage.

However, in a dimming filter using a liquid crystal element, a loss of light amount occurs even when the maximum transmittance is set. Therefore, it is preferable to provide the same slide mechanism as in FIGS. 8 and 9, and to replace the liquid crystal element and the transparent plate. As a result, the maximum transmittance can be secured when the transparent plate is selected, and the stepless transmittance can be adjusted according to the applied voltage when the liquid crystal element is selected.

(Detection of monitor light)
Since the mirror 310 moves at high speed, it may collide with dust floating in the air during operation and dust may adhere to the moving portion. Therefore, it is necessary to assemble in a clean environment without dust and to seal it from the outside air. For example, as shown in FIG. 5, the mirror 310 is mounted on a ceramic package, covered with a ceramic cover, and sealed with a dustproof cover glass 400. The cover glass 400 is a transparent plate that is arranged on the optical path between the dimming filter 24 and the mirror 310 and forms a part of a member that seals the mirror 310.

A method of preventing dust from the mirror 310 by sealing the entire optical scanning control device 1 instead of sealing only the mirror 310 is also conceivable. In this method, since the LD module 21 is also sealed, the sealing volume becomes large and the factor of generating dust inside increases, so that the sealing difficulty becomes high.

On the other hand, in the method of sealing only the mirror 310, the sealing volume becomes small and it is easy to suppress the mixing and generation of dust. However, if the reflected light from the cover glass 400 is not properly treated, there is a concern that it may cause stray light. In the present embodiment, only the mirror 310 is sealed by the cover glass 400, the light reflected by the cover glass 400 is effectively used, and the light is used to correct the wavelength variation of the dimming filter 24. This will be described in detail below.

FIG. 10 is a diagram illustrating a monitor for reflected light from the cover glass. As shown in FIG. 10, transmission light L ₁ having passed through the neutral density filter 24 is incident on the cover glass 400. Since the cover glass 400 is designed so that the transmission loss is small, most of the transmitted light L ₁ is transmitted through the cover glass 400 and is incident on the mirror 310 as the transmitted light L ₃ . However, a very small part of the transmitted light L ₁ is reflected by the cover glass 400 to become the reflected light L ₄ .

The cover glass 400 has a reference position of the mirror 310 rather than a deflection angle with respect to the reference position of the mirror 310 in order to separate the scanning light L ₅ scanned by the mirror 310 and the reflected light L ₄ reflected by the cover glass 400. It is arranged with a large inclination angle. The light amount detection sensor 60 is arranged at a position where the reflected light L ₄ on the cover glass 400 is incident and the scanning light L ₅ scanned by the mirror 310 is not incident.

For example, if the runout angle of the mirror 310 is ± 3 degrees with respect to the reference position, the cover glass 400 may be arranged at an inclination angle larger than 3 degrees with respect to the reference position, but the cover may be arranged in consideration of the design margin. The inclination angle of the glass 400 with respect to the reference position is preferably about 23 degrees.

As described above, the cover glass 400 plays a role of sealing the mirror 310 and a role of separating the transmitted light L ₃ which is a light ray for drawing and the reflected light L ₄ which is a light ray for light amount monitoring. Light-power detection sensor 60, based on the amount of the reflected light L _4, as described above, detects the amount of laser light, including the variation in the characteristics of the neutral density filter 24, as a result, are actually displayed on the screen 50 It is possible to accurately control the amount of light corresponding to the image.

Since the reflected light L ₄ is the light before being scanned by the mirror 310, it is preferable in that the light amount detection sensor 60 can monitor the light having a higher density than the case where the light after being scanned is monitored.

Although the preferred embodiment has been described in detail above, it is not limited to the above-described embodiment, and various modifications and substitutions are made to the above-described embodiment without departing from the scope of claims. Can be added.

For example, in the above embodiment, an example of applying the optical scanning control device according to the present invention to a laser scanning projector has been shown. However, this is just an example, and the optical scanning control device according to the present invention can be applied to various devices for displaying an image on a screen. Examples of such a device include an in-vehicle head-up display, a laser printer, a laser scanning epilator, a laser headlamp, a laser radar, and the like.

Further, in the above embodiment, an example having three lasers is shown, but it is sufficient to have at least one laser. In this case, a monochromatic optical scanning control device can be realized.

1 Optical scanning controller 10 Circuit unit 11 System controller 12 CPU
13 Buffer circuit 14 Mirror drive circuit 15 Laser drive circuit 16 Temperature control circuit 20 Light source unit 21 LD module 22 Temperature control unit 23 Temperature sensor 24 Dimming filter 30 Optical scanning unit 40 Optical unit 41, 42, 43 Reflection mirror 44 Concave mirror 50 Screen 60 Light amount detection sensor 70 Anti-reflection structure 100 Housing 150 Unit 211R, 211G, 211B Laser 215 Light amount detection sensor 219 Exit 310 Mirror 351, 352, 371, 372 Drive beam 391 Horizontal displacement sensor 395, 396 Vertical displacement sensor 400 Cover Glass 410 Holding structure 420 Holder 430 Shaft 440 Shaft holding part 710, 720, 730 Plate 730 x Incident port

Claims (4)

A dimming means that dims and transmits the light emitted from the laser,
A scanning means that scans the light transmitted through the dimming means in two dimensions in the horizontal and vertical directions according to the video signal and forms an image on the screen .
A first light amount detecting means for detecting the amount of light before passing through the dimming means, and
A transparent plate arranged on an optical path between the dimming means and the scanning means and forming a part of a member for sealing the scanning means.
It has a second light amount detecting means for detecting the amount of light after passing through the dimming means.
The second light amount detecting means is an optical scanning control device that detects the light amount of the reflected light reflected by the transparent plate. The optical scanning control device according to claim 1, wherein the second light amount detecting means is arranged outside the range in which the reflected light is incident and the light is scanned by the scanning means. It has a first reflecting mirror that reflects the scanning light from the scanning means and a second reflecting mirror that reflects the reflected light from the first reflecting mirror.
The transparent plate reflects the laser light before being scanned by the scanning means and is incident on the second light amount detecting means located between the first reflecting mirror and the second reflecting mirror. The optical scanning control device according to claim 1 or 2, wherein the optical scanning control device is arranged so as to be inclined at an angle larger than the deflection angle of the scanning means with respect to the reference position . Optical scanning control apparatus according to any one of claims 1 to 3 the amount of light emitted from the laser based on the light quantity said first and said second light quantity detecting means has detected is controlled.