JPH02232617A - Light beam scanning device - Google Patents

Abstract

PURPOSE:To make the moving speed of a light beam high and uniform and to shorten a write time for one image plane by providing a means for changing the rate of change of a driving signal for driving a light beam scanning means in accordance with a distance which should be scanned with the light beam. CONSTITUTION:The rate of change of a lamp signal which is added to galvanomirrors 3 and 5 as the driving signal is changed in accordance with the moving distance of the light beam. By respectively using the two galvanomirrors 3 and 5 for the scanning in the respective axis directions of two dimension, for example, the moving speed of the light beam becomes the square of that of the light beam at the time of using one galvanomirror in the respective axis directions, so that high speed write is accomplished. Thus, a light beam scanning device in which the rising of the moving speed of the light beam is fast is obtained and the write time for the image plane full of character and symbol, etc., is especially shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a light beam scanning device, and more particularly to a means for speeding up the scanning of a light beam scanning device that performs vector scanning of a light beam. [Technology] A light beam scanning device that connects arbitrary two points with a light beam generated by a laser and performs two-dimensional scanning in a so-called vector scan is used for displays that use lasers to display on walls, etc., or for displays that use smectic liquid crystal elements. It is widely used in thermal writing liquid crystal projection displays, as well as in various optical measurement fields.Vector scanning type light beam scanning mainly uses galvano mirrors that scan the light beam by changing the angle of the mirror. The control of this galvano mirror is based on the Technical Report IPD6 of the Television Society of Japan.
6-1 (1982), pages 1 to 6, a ramp signal with a constant slope is used. ? Problems to be Solved by the Invention] The drive signal and movement of the light beam on the scanning surface in a conventional light beam scanning device using a galvano mirror will be explained. FIG. 12 is a diagram showing the relationship between the collective motion signal of the light beam scanning device and the movement of the light beam in the prior art. 12th
The figure shows, from the top, the rolling signal waveform, changes in the position of the light beam, and changes in the moving speed of the light beam over time. Generally, a ramp signal waveform with a constant rate of change Δa/Δt is used as a drive signal for a vector scanning type optical beam scanning device that scans between two arbitrary points. In the figure, one scan is defined as the period from standing still at an arbitrary point A on the scanning surface to moving to a relatively distant point B and stopping. The dynamic signal I■ changes to a drive signal amplitude a corresponding to the distance between points A and B at a rise time of t3. Following changes in this drive signal, the galvanometer mirror moves,
The light beam moves. This movement is shown as a position change x3 of the light beam from point A to point B. Furthermore, the movement of this light beam? Denote the velocity as V. The light beam is an egg movement signal■1
However, due to the mechanical delay element of the galvanometer mirror. It does not become uniform motion immediately, but gradually increases its speed during the acceleration period tr3, and eventually enters the maximum speed of uniform motion, and when the uniform velocity period tm ends, the speed gradually decreases, and the speed reaches the deceleration period tf. After ■, it reaches point B and stops.
Next, we will explain the case of moving from point A to relatively nearby point C. Moving signal ■. is the point A and point C at the rise time t4.
The drive signal amplitude 11 corresponds to the amount of movement b, which corresponds to the distance of
It changes up to 11Ta4. The rate of change Δa/Δt at this time is the same as the beating signal I. The position change of this light beam is shown as X4, and the speed change is shown as ■. When the light beam moves from point A to point C, the speed increases during the acceleration period tr, due to the mechanical delay element of the galvano mirror, but if the amount of movement is very small (b, < b,) ，
The deceleration period tf does not enter uniform motion. It enters and eventually comes to rest. The maximum speed v4 at this time is lower than the maximum speed (uniform velocity period) Vm when moving from point A to point B. Therefore, the time required for movement t tota Q is tto from point A to point B, respectively.
taR, = t r, + t rr+, + t f, and point A → point C becomes ttotaQ4 = t r'4 + t
f4, but as shown in Figure 4, tr, and tr4,
tf3 and tf. There is not much difference, and in the end, t tot
a Q 4/ttotau,>b4/bs (=a*/
aa), and moving between nearby points takes a relatively long time compared to moving between far points. As a result, with conventional light beam scanning devices, it takes a long time to write characters and symbols that often move between neighboring points, resulting in a long writing time per screen. In addition, there is a large difference in the speed of movement between far points and movement between nearby points, resulting in a disadvantage that, for example, when applied to a thermal writing liquid crystal display, there is a difference in the thickness of the written line. was there.

An object of the present invention is to provide a light beam scanning device in which the movement of the light beam is faster and more uniform, and the writing time for one screen is shorter. [Means for solving the problem] The above purpose focuses on the movement of a light beam between neighboring points,
Firstly, the slope of the ramp signal, which is a drive signal, is changed according to the moving distance of the light beam, and secondly, a plurality of light beam deflectors are used in a superimposed manner for one deflection direction of one light beam, Thirdly, this is achieved by minimizing the number of times the light beam remains stationary during the movement of a series of light beams. That is, the present invention aims to achieve the above objects.
A light beam generating means for outputting a light beam. ! A light beam scanning device comprising a light beam scanning means for vector scanning the light beam by a scanning mechanism including an I-mechanical delay element, and a control section for controlling the light beam generating means and the light beam scanning means to write figures such as characters. proposes a light beam scanning device in which the control unit includes means for changing the rate of change of a drive signal for activating the light beam scanning means in accordance with the distance to be scanned by the light beam. The correspondence relationship between the distance to be scanned and the rate of change may be stored in advance in the storage unit as a waste movement pattern, and may be recalled without being calculated each time the scan is performed. The waste movement pattern does not need to be smooth; it is also possible to use a broken line approximation that divides the distance to be scanned into several parts and makes each part correspond to a constant rate of change. The present invention also provides a light beam generating means for emitting a light beam, a light beam scanning means for vector scanning the light beam by a scanning mechanism including a mechanical delay element, and controlling the light beam generating means and the light beam scanning means. In the light beam scanning device, the light beam scanning means includes a plurality of light beam deflection means that are used in a superposed manner in one deflection direction of one light beam. This paper proposes a light beam scanning device.

The present invention further provides a light beam generating means for emitting a light beam, a light beam scanning means for vector scanning the light beam by a scanning device including a mechanical delay element, and the light beam generating means and the light beam scanning means. In the light beam scanning device, the control unit breaks down a plurality of figures to be written on one screen into line segments, and once determines the scanning direction common to each figure. This paper proposes a light beam scanning device that is equipped with a means for determining the scanning order so that the light beams are scanned in the same way. These measures are effective when used alone, but they can also be used in combination. In addition, at the start of the scanning, an acousto-optic deflection element with a small deflection amount but no mechanical delay is used to compensate for the mechanical delay of the light beam scanning means, and the subsequent large scan is performed by the light beam scanning with the mechanical delay. It is also possible to adopt a complex configuration in which the means are in charge. [Operation] The operation of each of the above means will be explained. First, we will explain how the rate of change of the lamp signal applied to the galvanometer mirror as the M dynamic signal is changed according to the distance traveled by the light beam. If the amplitude of the ramp signal is kept constant and the rate of change is varied, there is a limit at which the galvano mirror stops operating above a certain rate of change. Conventionally, the rate of change of the lamp signal is fixed to operate stably with the amplitude of the lamp signal that provides the maximum width that the light beam moves, and only the amplitude is changed with the rate of change constant as the distance the light beam moves. Ta. However, as shown in Figure 12, when the distance between two points is short and the ramp signal has a very small amplitude and there is no constant velocity region, the galvanometer mirror operates stably even in regions where the rate of change of the ramp signal is large. I found out. Therefore, when moving between neighboring points when writing characters or symbols, increasing the rate of change of the ramp signal, which is the drive signal applied to the galvanometer mirror, will shorten the acceleration period when the stationary light beam starts moving. , scanning between neighboring points of a character or symbol can be done in a shorter time. Next, we will explain how multiple light beam scanning means are superimposed to perform scanning in a single direction. For example, for scanning in each 2D axis direction, 2
Galvanometer mirrors are used. In this configuration, the speed of movement of the light beam is the square of the speed of movement of the light beam when one galvanometer mirror is used in each axis direction, making high-speed writing possible. In addition, the maximum swing width required for each galvano mirror is 1/2 that of a single galvano mirror, and can be larger than the rate of change of the lamp signal as a swing signal. Another configuration uses an acousto-optic deflection element and a galvano mirror. Acousto-optic deflection elements have no mechanical delay and can move the light beam almost instantaneously. Furthermore, by reducing the rest of the light beam that occurs during a series of movements of the light beam, for example in a thermal writing liquid crystal projection display, until the image on the screen is completely written, the acceleration and deceleration periods can be reduced, and even at maximum speed. The period of constant movement is increased, and the writing time is shortened.

〔Example〕

Next, embodiments of the present invention will be described in detail. Figures 1 to 4 show embodiments and operation examples of means for changing the slope of the ramp signal. Fig. 1 is a diagram showing the configuration of the light beam scanning device, Fig. 2 is a diagram showing the drive signal and the operation of the light beam,
Figures 3 and 4 are diagrams showing the operating state. The configuration of the light beam scanning device shown in Figure 1 will be explained. A light beam 2 generated by a laser 1 is reflected by a mirror 3. The mirror 3 is a galvanometer mirror whose angle can be changed by a mirror moving part 4. The light beam 2 reflected by the mirror 3 is further reflected by the mirror 5. mirror 5
is a galvanometer mirror whose angle can be changed by a mirror active part 6. The light beam 2 reflected by the mirror 5 is
The light is focused on a minute spot by the condensing lens 7, and the light is focused on the scanning surface 8.
Scan above. What are the signals that move the mirror drive units 4 and 6 and the signals that control the laser 1? It is output from the control unit 9. The direction in which the light beam 2 is scanned by changing the angle of the mirror 3 and the direction in which it is scanned by changing the angle of the mirror 5 are perpendicular to each other, and the light beam 2 is scanned two-dimensionally. A case where the light beam 2 is moved from a stationary state at a point A on the scanning surface 8 to a point B which is a far point in the horizontal direction;
Similarly, point C, which is a nearby point, from a state where it is stationary at point A
An example of the operation when moving up to
FIG. 2 shows, from the top, the drive signal waveforms applied to the mirror drive,
It shows changes in the position of the light beam and changes in the speed of movement of the light beam. The broken line indicates movement from point A to point B, and the solid line indicates movement from point A to point C. When moving from point A to point B, the striking signal I to be applied to the mirror striking part is a ramp signal with an amplitude of a and a rise time of t1. This drive signal engineer,
When is applied to the mirror sliding part, the light beam moves from point A to point B by an amount of movement Xm along the positional change X1, and then comes to rest.
In this case, the moving speed v1 starts to rise as the rolling signal begins to rise, and tr gradually increases its speed during the acceleration period 11, and the speed Vrn
When it reaches , it moves at a constant speed. Constant velocity period tm 1
After 2, the speed is gradually reduced during the deceleration period tf113, and the speed is gradually reduced to point B.
It reaches and stops. Therefore, the time it takes for the light beam to move from point A to point B until it stops is ttot1. , is t
totaml: t r, + t m1 + t fl. On the other hand, when the light beam moves from point A to point C, a drive signal device 2 is added to the mirror parking part. As shown in FIG. 3, the amplitude a2 of the drive signal 2 becomes smaller in proportion to the amount of movement, but the rise time t2? The rate of change a,/t is the rate of change az/t of the drive signal.
It is larger than tl. Adding the drive signal I2,
The light beam moves by a moving amount xm■ and comes to rest at point C. At this time, the moving speed v2 increases during the acceleration period tr, and moves at a constant speed Vm. After the constant velocity period tm, the vehicle enters a deceleration period tf■ and gradually lowers its speed and comes to a standstill at point C.
The time required for this movement is ttota. g is t tot
a. , = t r, + b m, + t f.

The travel time ttotatl between far points from point A to point B is the same as the conventional example shown in FIG. It will be shorter than 101114. In other words, by increasing the slope of the tapping signal, the speed increases faster, and even when moving between neighboring points, the speed reaches the maximum speed Vm, creating an area where the object moves at a constant speed, and reducing the moving time. ．． Figure 3 shows the relationship between the amplitude and rise time of the drive signal. For reference, the conventional relationship is shown with a dashed line. Conventionally, the amplitude of the oscillation signal, that is, the amount of movement of the light beam, and the rise time were in a proportional relationship. In the present invention, as shown by the solid line,
As the travel distance of the light beam becomes shorter, the rise time is shortened. The relationship between the amount of movement of the light beam and the time required for movement when moving the light beam using these signals is shown in Part 4. The dashed line is the case when a conventional suspicious motion signal is used, and the solid line is the case according to the present invention. With conventional drive signals that have a proportional relationship, the time required to move at nearby points is almost constant. On the other hand, in the present invention, although there is still some delay compared to the ideal state, the time is reduced to about 172 at most compared to the conventional method. As shown in Figure 3, the inclination a/t of the rotation signal changes depending on the amount of movement of the light beam, but in the case of a high-definition screen with address points of 1000 x 10oO dots or more, such as a thermal writing liquid crystal projection display. , it may be a national problem to set the slope for each amount of movement. At this time, the amount of movement is divided into blocks, and the change in inclination is approximated by a broken line. The method will be explained using Figures 5 and 6. Fifth
The figure is an example of a control circuit for polygonal line approximation. The galvanometer mirror drive command output circuit 30 outputs a command signal for generating a drive signal corresponding to the movement of the light beam. Using this signal, a drive pattern corresponding to the amount of movement stored in the drive pattern memory 31 in advance is read out. The read drive pattern is converted by the digital-to-analog converter 32 and sent to the amplifier 33 to obtain a drive signal for driving the mirror drive unit 34. The mirror drive unit 34 changes the angle of the mirror 35 to scan the light beam. An example of the contents of the pre-stored translation pattern memory 31 is shown in FIG. In this embodiment, there are five patterns D to D depending on the amount of movement of the light beam.
It is divided into D. The method and number of divisions can be determined arbitrarily, depending on the galvanometer mirror's scanning ability and the scanning width of the light beam.
If the slope of the active signal is made into a polygonal line as in this example,
This reduces the load on the circuit and enables high-speed scanning. FIG. 7 shows an embodiment of a light beam scanning device that performs two-dimensional vector scanning. Light beam 41 generated by laser 4o
is reflected by mirror 42. The angle of the mirror 42 can be changed by a mirror north moving part 43. The light beam 41 reflected by the mirror 42 is incident on a lens 44 and further incident on a lens 45. Lens 44 and lens 45 form a relay lens and transmit the movement of light beam 41 caused by mirror 42 to mirror 46. The angle of the mirror 46 can be changed by a mirror drive unit 47. The light beam 41 reflected by the mirror 46 enters the condenser lens 48. Scanning plane 49
Scan the top in two dimensions. A control section 39 controls a laser 40 and mirror moving sections 43 and 47. In this example. To transfer the movement of the light beam 41 due to the movement of the mirror 42 to a change in the angle of incidence on the mirror 46 by lenses 44 and 45, which serve as relay lenses. The size of the mirror 46 can be reduced, scanning can be made faster, and the acceleration period can be shortened. Next, an embodiment of the present invention using a plurality of beam deflection means will be described. In FIG. 8, a light beam 51 generated by a laser 5o is reflected by a mirror 52. The angle of the mirror 52 is changed by a mirror drive unit 53 to deflect the light beam 51 in a first direction. Light beam 5 reflected by mirror 52
1 passes through lenses 54 and 55, and passes through mirror 56.
reflected by. The lens 54 and the lens 55 form a relay lens, and convert the movement of the scanned light beam 51 by changing the angle of the mirror 52 into a change in the angle of incidence on the mirror 56. The angle of the mirror 56 is changed by a mirror moving part 57 to deflect the light beam 51 in a second direction. mirror 5
The light beam 51 reflected by the lens 6 passes through the lenses 58 and 59 and is reflected by the mirror 60. lens 5
8 and lens 59 form a relay lens, and mirror 52
The movement of the scanned light beam 51 is converted into a change in the incident angle of the mirror 60 by changing the angle of the mirror 56.

The mirror 60 is connected to a mirror drive section 61. changes its angle, further deflecting the light beam 51 in a second direction.
The light beam 51 reflected by the mirror 60 passes through a lens 62 and a lens 63, and is reflected by a mirror 64.
Lens 62 and lens 63 form a relay lens, and the movement of scanned light beam 51 is converted into a change in the incident angle of mirror 64 by changing the angle of mirror 52, mirror 56, and mirror 60. The mirror 64 has its angle changed by a mirror active part 65 to further deflect the light beam 51 in a first direction. The light beam reflected by the mirror 64 is focused by a condenser lens 66 and scans on a scanning surface 67. The laser 50 and the four mirror drive units 53, 57, 61, and 65 are controlled by signals from a control unit 68. In this embodiment, in the two-dimensional first direction, the angle changes of the mirrors 52 and 64 are scanned while being scanned, and in the second direction, the angle changes of the mirrors 56 and 60 are scanned. The scanning angle is twice that of scanning with only one mirror, and the speed of the light beam becomes faster. Another embodiment of the present invention using a plurality of beam deflection means will be described with reference to FIGS. 9 and 10.

Figure 9 shows the ellipse of the optical beam scanning device. The light beam 7l generated by the laser 70 is transmitted to the acousto-optic deflection element 72.
and is scanned in the first direction.

The light beam 7l scanned in the first direction passes through a lens 73 and a lens 74, and enters an acousto-optic deflection element 75. The lens 73 and the lens 74 form a relay lens, and convert the movement of the light beam 7l scanned by the acousto-optic deflection element 72 into a change in the incident angle of the acousto-optic deflection element 75. The acousto-optic deflection element 75 deflects and scans the light beam 7l in a second direction. The scanned light beam 71 passes through the lens 76
The light passes through the lens 77 and is reflected by the mirror 78. The lens 76 and the lens 77 function as relay lenses and convert the movement of the light beam 71 deflected by the acousto-optic deflection element 72 and the acousto-optic deflection element 75 into a change in the angle of incidence on the mirror 78. The angle of the mirror 78 is changed by a mirror drive unit 79,
The light beam 71 is scanned in a first direction. The light beam 71 reflected by the mirror 78 passes through the lens 80 and the lens 8
1 and enters the mirror 82. The lens 8o and the lens 81 are relay lenses, and convert the movement of the light beam 71 scanned by the two acousto-optic deflection elements 72 and 75 and the mirror 78 into a change in the angle of incidence on the mirror 82. The angle of the mirror 82 can be changed by a mirror drive unit 83.
The light beam 71 is further deflected in a second direction. mirror 8
The light beam 71 reflected by 2 is condensed by a condenser lens 84 and scans a scanning surface 85 two-dimensionally. The control unit 86 includes a laser 70, two acousto-optic deflection elements 72 and 75, and two
Controls two mirror drive units 79 and 83. The sliding method will be explained using FIG. 10.

For simplicity, we will only consider movement in the horizontal direction. The mirror drive signal signal is a drive signal given to the mirror active section 79, and rises to a constant slope and amplitude a at a rise time t5. This drive signal moves the mirror drive unit 79, changes the angle of the mirror 80, deflects the light beam 71, and scans the scanning surface 85. The movement of the light beam 71 on the scanning surface 85 at this time is as shown by the broken line X in the middle graph, and there is a mechanical lag. The change in the moving speed of the light beam at this time is the moving speed V, which is shown by the broken line in the lower graph.
The vehicle increases its speed during the acceleration period tr, moves at the maximum speed during the constant speed period tm, and then decelerates. When scanning a light beam at high speed, shortening this acceleration period tr becomes an issue. This acceleration period tp is shortened by using an acousto-optic deflection element. The acousto-optic deflection element uses ultrasonic waves to form a diffraction grating in a crystal that has an acousto-optic effect, and deflects light by diffraction, and is characterized by no mechanical delay. When the movement of the light beam 71 on the scanning surface 85 becomes a solid line X7 in the middle graph, the light beam moves at a constant speed over the entire area between the two points. Therefore, the difference between the solid line X7 and the movement of the light beam by the mirror IIAxs is corrected by an acousto-optic deflection element. At the same time as applying the mirror annotation signal I, an acousto-optic deflection element active signal ■ is applied. The light beam moves as indicated by the dotted line X by the acousto-optic deflection element. The movement of the light beam by the acousto-optic deflection element continues for an acceleration period tr, until the movement of the light beam by the mirror reaches a constant speed, and the amount of movement is X, which is the actual amount of movement of the light beam X. When the rise time t of the mirror striking signal, which is equal to the difference between the amount of movement of the light beam due to the mirror alone and X, has elapsed. The light beam reaches the end of the scan. The scanning between the two points is completed by turning off the laser at the moment it reaches the point, and at this time, the vibration signal (6) of the acousto-optic deflection element is also turned off. The moving speed of the light beam during this process is as shown in the graph below, and the light beam moves at a constant speed from the moment the mirror movement signal ■5 is applied. According to this embodiment, the movement of the light beam over any distance is a constant movement. Although the driving method in each of the above embodiments has been explained in the case of horizontal scanning, the same applies to the case of vertical scanning or the case of diagonal scanning which is a combination thereof. Next, we will explain a scanning method that minimizes the stationary state of the light beam. FIG. 11 considers the case where figures 1 to 4, which are rectangles, are written on the scanning surface 100. If you have the relative coordinates of symbol figures in a microprogram, etc., even if there are four rectangular shapes lined up, as in the example in Figure 11, they will be changed in the order of figure 1, figure 2, figure 3, and figure 4, respectively. Draw a rectangle from the starting point of the microprogram. The scanning order always starts from the upper left corner point.

An example of the procedure is shown in (B) as a conventional example. The dots with the names circled are. This indicates the point at which the movement of a mirror, etc. once stops and then starts moving again. As already mentioned, if the mirror etc. stops during a series of scans, the scanning time becomes longer due to the mechanical delay in the mirror wear parts. Therefore, it is possible to break down the symbols, characters, etc. to be written in a series of scans into line segments, shorten the distance that the light beam l1 moves during scanning, and reduce the number of times the mirror etc. stops as much as possible. ．． Scanning time is reduced. Shown in Figure 11(C). According to the scanning system of the present invention, the travel distance of the light beam is reduced by about 10% compared to the conventional example, and the number of stops is reduced from 19 to 13, making it possible to significantly shorten the scanning time. Each of the above methods is effective when used alone, but even greater effects can be obtained by combining them. That is, the speed has been increased by at least three times, and in particular, when displaying kanji characters that frequently move to neighboring points, an overall speedup of about 10 times has been achieved.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a light beam scanning device in which the moving speed of the light beam rises quickly, and in particular, it is possible to reduce the writing time for a screen with many characters, symbols, etc. to about one-tenth at most.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment of a light beam scanning device according to the present invention, FIG. 2 is a diagram showing the drive signal and the operation of the light beam, and FIG. 3 is a diagram showing the relationship between the travel amount and the rise time of the light beam. FIG. 4 is a diagram showing the relationship between the amount of movement of the light beam and the time required for the movement. FIG. 5 is a diagram showing an example of a control circuit for approximating the movable movement pattern of the galvanometer mirror with a broken line. FIG. 6 is a diagram showing an example of a broken line approximation pattern stored in the drive pattern memory, FIG. 7 is a diagram showing an example of a light beam scanning device that performs two-dimensional vector scanning, and FIG. 8 is a diagram showing a plurality of light beam deflections. FIG. 9 is a diagram showing an embodiment of the present invention using a mirror and an acousto-optic deflection element, and FIG. 10 is a diagram showing a rotating method of the embodiment of FIG. 9. Figures 11 and 11 are diagrams showing a scanning method for minimizing the stationary state of a light beam, and Figure 12 is a diagram showing a method for swinging a conventional light beam scanning device. 1... Laser, 2... Light beam, 3, 5... Mirror 4, 6... Mi. 7. Condensing lens,
8... Scanning surface, 9... Control unit, 30... Galvanometer mirror movement command output circuit, 3l... Drive pattern memory, 32... Digital analog converter, 33... Amplifier, 34 ...Mirror drive unit. 35...mirror, 3
9...Control unit, 40...Laser, 41...Light beam. 42.46...Mirror, 43.47...Mirror drive section. 44.45...Relay lens, 48...Condensing lens, 49...Scanning surface, 50...Laser, 51
... light beam, 52.56 ... mirror, 53.57
...Mirror drive unit, 54.55...Relay lens.
58.59... Relay lens, 60.64... Mirror, 61.65... Mirror drive unit, 62.63...
Relay lens, 66... Condensing lens, 67... Scanning surface, 68... Control circuit, 70... Laser, 71...
・Light beam, 72.75... Acousto-optic deflection element, 73
, 74, 76, 77, 80.81... relay lens,
78, 82... Mirror 79, 83... Mirror drive section. 84... Condensing lens, 85... Scanning surface, 86...
...Control unit, 100...Scanning plane. Figure 1

Claims (1)

[Scope of Claims] 1. A light beam generating means for outputting a light beam, a light beam scanning means for vector scanning the light beam by a scanning mechanism including a mechanical delay element, and the light beam generating means and the light beam scanning means. In the light beam scanning device, the control unit controls the rate of change of the drive signal for driving the light beam scanning means according to the distance to be scanned by the light beam. What is claimed is: 1. A light beam scanning device characterized by comprising means for changing the light beam. 2. The light beam scanning device according to claim 1, wherein the control section includes a storage section that stores in advance a correspondence relationship between a distance to be scanned and a rate of change as a drive pattern. Beam scanning device. 3. The light beam scanning device according to claim 1 or 2, characterized in that the control section includes broken line approximation means that divides the distance to be scanned into several parts and makes each part correspond to a constant rate of change. A light beam scanning device. 4. A light beam generating means for outputting a light beam; a light beam scanning means for vector scanning the light beam by a scanning mechanism including a mechanical delay element; A light beam scanning device comprising a control unit for drawing a figure, characterized in that the light beam scanning means includes a plurality of light beam deflection means used in a superposed manner in one deflection direction of one light beam. A light beam scanning device. 5. A light beam generating means for outputting a light beam; a light beam scanning means for vector scanning the light beam by a scanning mechanism including a mechanical delay element; A light beam scanning device comprising a control unit for drawing figures, wherein the control unit breaks down a plurality of figures to be drawn on one screen into line segments, and scans a scanning direction common to each figure at once. A light beam scanning device comprising means for determining a scanning order. 6. The light beam scanning device according to any one of claims 1 to 3, wherein the light beam scanning means includes a plurality of light beam deflection means used in a superposed manner in one deflection direction of one light beam. A light beam scanning device comprising: 7. The light beam scanning device according to any one of claims 1 to 4 or 6, wherein the control unit decomposes a plurality of figures to be written on one screen into line segments and determines a common scanning direction for each figure. 1. A light beam scanning device, comprising means for determining a scanning order so that all the light beams are scanned at once. 8. A light beam generating means for outputting a light beam; a light beam scanning means for vector scanning the light beam by a scanning mechanism including a mechanical delay element; In the light beam scanning device, the light beam scanning means has an acousto-optic deflection element that has a small amount of deflection but no mechanical delay, and the acousto-optic deflection element allows the light beam to be scanned at the start of the scan. A light beam scanning device, wherein the mechanical delay is compensated for, and after the mechanical delay element starts up, scanning is performed by a main scanning mechanism including the mechanical delay element. 9. The light beam scanning device according to any one of claims 1 to 7, wherein the light beam scanning means has an acousto-optic deflection element having a small amount of deflection but no mechanical delay, and the acousto-optic deflection A light beam scanning device, wherein the mechanical movement is compensated by an element at the start of scanning, and after the mechanical delay element starts up, scanning is performed by a main scanning mechanism including the mechanical delay element.