JP2005331464A - Laser light generating apparatus, line light generating optical system, and laser marking apparatus equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser light generating apparatus, a line light generation optical system, and a laser marking apparatus to optimize the apparent brightness of the line light at various irradiation distances. <P>SOLUTION: The laser marking apparatus is provided with a distance measuring function for measuring irradiation distances, and the oscillation condition of a laser is controlled so that the apparent brightness of the line light becomes constant, according to irradiation distances. The apparent brightness of the line light is improved on the basis of the Broca-Sulzer effect, without changing the laser power of a light source. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a line light generating optical system capable of generating line light having a narrow line width and an extremely wide spread angle, and a laser marking device equipped with the line light generating optical system.

  Laser pointers and laser marking devices are known as devices that output laser terms as display light (see, for example, Patent Documents 1 to 3).

  In these apparatuses, laser light is used as display light. For the safety of the eyes, the light intensity needs to be a predetermined value (for example, 1 mW) or less. In the laser marking device, dot-shaped laser light is extended into a line shape and used as display light. In these cases, since the light intensity per unit area of the line light is smaller than the original dot-shaped laser light, the line light is more difficult to recognize than the dot light. That is, since the recognizability of the display light depends on the light intensity per unit area of the display light, in the case of a laser marking device, the area of the line light increases as the length of the line light increases. Intensity is reduced and recognition is reduced. The length of the line light increases in proportion to the distance from the laser marking device to the irradiation target. That is, in the current marking device, the distance at which line light can be visually recognized is up to about 10 m, and it is difficult to recognize line light when irradiating longer distances. It is a commonly used method to find out the light irradiation position and perform the ink marking work. In order to obtain line light that can be recognized over a long distance, there is a method of rotating the dot light with high light intensity per unit area to draw an afterimage of the line on the irradiation object and recognize it (eg Topcon rotating laser). . In this case, a mechanism for rotating the light source with high accuracy is required, which increases the size and cost of the apparatus.

  In addition, in the laser pointer of patent document 1, it can switch from continuous lighting to pulse lighting. In addition, the pulse lighting frequency and pulse width can be switched.

  In the laser pointer of Patent Document 2, the semiconductor laser is blinked at a frequency of 8 to 16 Hz so that the laser light can be easily recognized by human eyes.

  Further, in the laser marking device of Patent Document 3, the semiconductor laser can be switched between a pulse state and a continuous light state. The pulse period of the semiconductor laser can also be changed. The on-duty ratio of the semiconductor laser can also be changed.

JP-A-3-200994

JP-A-7-94815 JP-A-11-295070

  Conventional devices that output laser light as display light, such as laser pointers and laser marking devices, are used by changing the distance to the display object in various ways. In the case of a laser pointer, the display light has a dot shape, so even if the distance to the display object increases, the area of the display light hardly changes, the light intensity per unit area does not change greatly, and the recognizability There is almost no drop in. On the other hand, in the case of a laser marking device, the display light is a light that spreads in a fan shape and forms a line when it is irradiated onto the object, so that the length of the line light increases in proportion to the irradiation distance. That is, when the irradiation distance is increased, the area of the line light is increased, the light intensity per unit area is decreased, and the recognizability is decreased. Therefore, in order to improve the recognizability, it is necessary to increase the light output of the original light source and increase the light intensity per unit area. On the other hand, there is a restriction that the light intensity is set to a predetermined value (for example, 1 mW) or less for the safety of eyes based on the laser equipment safety standards defined by law. Therefore, an upper limit is set for the light intensity per unit area, and as a result, a recognizable irradiation distance is determined. That is, there has been no laser marking device that can perform long-distance irradiation without increasing the output of the original light source and recognize line light.

  An object of the present invention is to solve such a conventional problem and to provide a laser marking device that complies with safety standards and can be recognized over a long distance.

  In order to achieve the above object, the present invention has one feature in that the line light is a blinking light. In general, the human retina feels flicker against pulsed light having a low frequency. However, when the frequency is equal to or higher than the critical fusion frequency (hereinafter referred to as CFF), the human retina fuses with flickering and feels the same brightness as continuous light. Here, the value of CFF varies depending on the individual and is not fixed, but is a frequency within a range of approximately 80 Hz to 100 Hz (referred to as a critical fusion frequency range CFFR).

  Assuming that the on-duty ratio and the absolute intensity of the light flashing at a frequency higher than CFF are D and I, respectively, the apparent brightness I ′ of the flashing light is expressed as I ′ = I · D according to Talbot's law. It is represented by Since D is less than 1, I ′ <I. Therefore, when a certain voltage is applied to the laser diode and blinked at CFF or higher, it feels darker than when the same voltage is applied to the same laser diode to cause continuous oscillation.

  On the other hand, if the frequency, on-duty ratio, and absolute intensity of the light flashing at a frequency smaller than CFF are f, D, and I, respectively, the apparent brightness I ′ of the flashing light is the lighting time of the flashing light. It increases with an increase in τ (= (1 / f) · D), and becomes larger than the apparent brightness of continuous light having an absolute intensity I, and eventually reaches a peak (Blocker Salzer effect). The apparent brightness I 'decreases as the lighting time τ further increases, and eventually stabilizes at a brightness equal to the apparent brightness of continuous light having the absolute intensity I.

  Here, the ratio (I ′ / I) between the apparent brightness I ′ and the absolute intensity I at the peak is defined as the blocker-Salzer effect index k. It is known that the peak lighting time τ and the blocker-Salzer effect index k differ depending on the magnitude of the absolute brightness I, as shown in Table 1 below (“visual psychology”). Physics ", page 167, Mitsuo Ikeda, Morikita Publishing, published on May 5, 1975).

  From Table 1, for example, when the absolute intensity I = 200 (Toroland (td)), the apparent brightness I ′ peaks at the duration τ = 0.03 (s), and the absolute intensity It can be seen that the apparent brightness of I continuous light is 5.5 times.

  According to Table 1, it can be seen that as the lighting time τ gradually increases from 0.03 (s) to 0.125 (s), the blocker-Salzer effect index k gradually decreases. In other words, by setting the lighting time per blinking light to about 0.125 (s) or less, the value of k can be set to 1 or more, and the apparent brightness is set to the appearance of continuous light. It can be seen that the brightness can be increased more than the brightness.

  Here, assuming that the duty ratio D = 50%, the duration τ = 0.03 (s), 0.04 (s), 0.062 (s), 0.1 (s), 0.125 (s) Corresponds to the blinking frequency f = 16.5 (Hz), 12.5 (Hz), 8.0 (Hz), 5.0 (Hz), 4.0 (Hz). Therefore, it can be seen that the apparent brightness can be increased from the apparent brightness of continuous light by driving the laser diode 32 with a combination of a drive frequency of 4 Hz or more and an on-duty ratio of 50% or less.

In addition, Toroland used here is a unit of retinal illuminance often used in visual system experiments. One Toroland (td) is retinal illuminance when a surface having a luminance of 1 cd · / m ² is viewed with a pupil area of 1 mm ² . The retinal illuminance represents the number of luminous fluxes per unit area on the retina.

  One of the features of the present invention is that line light is generated using a pulse laser as a light source for generating line light, and the illumination time per laser light when the laser is blinking is set to 125 ms or less to improve retinal illuminance. Thus, the line light recognition is improved while keeping the laser output as the original light source within the range of the safety standard. In general, human vision may recognize blinking light up to around 80 Hz. That is, it is possible to improve the recognizability of the generated line light by appropriately selecting the pulse oscillation frequency of the laser light within the range of 4 to 80 Hz. That is, another feature of the present invention is that pulsed laser light with an oscillation frequency of 4 to 80 Hz is used as a light source of the line light generation optical system, thereby improving retinal illuminance and improving line light recognition. It is in. In the case of a laser marking device, since the spread angle of the line light is constant, the length of the line light is proportional to the irradiation distance. For example, when the irradiation distance is doubled, the length of the line light is also doubled. Since the line width hardly changes, the area of the line light also doubles. As a result, since the light intensity per unit area is reduced to ½, the line light recognizability is also reduced. However, by increasing the apparent brightness of the line light by the blocker-Salzer effect, it becomes possible to improve the recognizability of the line light without changing the light output of the original light source. If the effect of increasing the apparent brightness of the line light based on the blocker-Salzer effect is exhibited over the entire irradiation distance used, the apparent brightness of the line light becomes too large at a short distance, causing the line light to be glaring. On the other hand, it may be difficult to see. Therefore, by adding an irradiation distance discriminating function to the laser marking device, an apparent brightness increase effect of the line light based on the blocker-Salzer effect is generated when the irradiation distance is such that the recognizability of the line light decreases. There are other features of the present invention.

  Another feature of the present invention is that a distance measuring function is added to the laser marking device, the irradiation distance is measured, and the apparent brightness of the line light is constant so that the recognizability of the line light is constant according to the irradiation distance. Is to optimize. The length of the line light generated from the laser marking device is proportional to the distance from the laser marking device to the irradiation surface.

  This will be described with reference to FIG. Assuming that the divergence angle of the line light is θ, the total length of the line light on the irradiated surface separated by the distance L is 2L · tan (θ / 2), so the line light length is the distance from the laser marking device to the irradiated surface. It is obvious that it changes in proportion to. Next, since the laser marking device is designed so that the line width of the line light is almost constant at all irradiation distances, the area of the line light is also proportional to the distance from the laser marking device to the irradiation surface. Become. Since the laser marking device is designed so that the laser power is always a constant value, the light intensity in the unit area of the line light (hereinafter referred to as the light intensity density) is the distance from the laser marking device to the irradiation surface. It changes in inverse proportion to. That is, as the irradiation distance becomes longer, the light intensity density of the line light becomes smaller, so that it becomes difficult to visually recognize the line light. By increasing the laser power, the light intensity density of the line light can be increased. However, in the case of a laser marking device, there is a restriction on the laser power based on the safety standards of the laser, so that the recognizability of the line light is improved. There is no reason to increase the laser power. Therefore, in the present invention, this is dealt with by increasing the apparent brightness of the line light while keeping the laser power at a constant value.

  Next, a specific method will be described. First, a reference line light intensity density (that is, a reference irradiation distance Ls) is set. Next, the distance L (however, Ls ≦ L) from the laser marking device to the irradiation surface is measured. The apparent brightness of the line light at the distance L becomes Ls / L times the apparent brightness of the line light at the reference irradiation position, and the brightness decreases.

  Therefore, by multiplying the apparent brightness by L / Ls, it is possible to match the apparent brightness of the line light at the irradiation distance L to that at the reference position. A description will be given of how to obtain the laser oscillation condition for changing the apparent brightness. FIG. 6 is a conceptual diagram showing the relationship between the apparent brightness ratio of line light and laser oscillation conditions (oscillation frequency, on-duty ratio). The vertical axis shows the ratio of apparent brightness when the line light is irradiated under specific conditions to the apparent brightness of the line light at the reference position (unit is dimensionless), and the horizontal axis shows the laser oscillation frequency. (Unit is Hz). A plurality of graphs when the on-duty ratio is changed are also displayed in the same chart. When the laser is pulse-oscillated at a frequency within a certain range due to the Blocker-Salzer effect, the apparent brightness increases and there is a frequency condition having a maximum peak. When the laser is oscillated out of the specific frequency range, the apparent brightness decreases and becomes a constant value. Further, since the apparent brightness of the line light changes in proportion to the on-duty ratio, the characteristic shown in FIG. 6 is exhibited. That is, the laser marking device of the present invention measures the distance L to the irradiation surface at the same time as the power is turned on, and based on the data shown in FIG. 6, the laser oscillation condition (the oscillation frequency and the oscillation frequency and the ratio L / Ls with the reference irradiation distance Ls) is obtained. On-duty ratio) is selected, and the line light is irradiated under the conditions. In this way, it becomes possible to always irradiate the line light with a constant brightness regardless of the irradiation distance.

  As described above, according to the laser beam generator of the present invention, the laser is driven by a combination of the optimum drive frequency and on-duty ratio according to the line light irradiation distance. It is possible to increase the apparent brightness of the line light and improve the recognizability even at the irradiation distance where the recognizability of light has been reduced. Further, the laser marking device of the present invention has a function to freely increase or decrease the apparent brightness of the line light according to the distance data to the line light irradiation surface, so that the apparent appearance of the line light at an arbitrary irradiation distance. It is possible to optimize the brightness and keep the apparent brightness of the line light almost constant over the entire irradiation distance.

The laser marking device of the present invention will be described with reference to FIGS.
FIG. 1 shows a laser marking device 1. The laser marking device 1 includes a line light generation optical system 2, a support mechanism unit 11 for keeping the line light generation optical system 2 horizontal, a case 16 that covers the line light generation optical system 2 and the support mechanism unit 11, and length measurement. The apparatus 100 is comprised. The support mechanism 11 uses a known gimbal mechanism. The gimbal mechanism includes a support frame 12, a large ring 13, a small ring 14, and a mounting base 15. The large ring 13 can swing around another H2 axis (perpendicular to the H1 axis and thus perpendicular to the paper surface) extending horizontally with respect to the support frame 12 by a bearing (not shown). A mounting base 15 on which the line light generating optical system 2 is mounted is fixed to the small ring 14. With this configuration, the mounting base 15 on which the line light generating optical system 2 is mounted can be kept horizontal.

  Next, the length measuring device will be described. As the length measuring device 100, for example, an ultrasonic length measuring device or a laser length measuring device is used. The length measuring device 100 may be built in the laser marking device 1 or independently provided that the length measurement data can be input to a microcomputer in the laser oscillation circuit built in the laser marking device 1. Also good. The length measuring device 100 is used at the stage of measuring the distance from the laser marking device 1 to the line light irradiation surface and optimizing the apparent brightness of the line light according to the distance data.

Next, the line light generating optical system 2 will be described with reference to FIG.
The line light generation optical system 2 includes a laser light source module 3, a pulse oscillation circuit 4, a collimator lens 5, and a rod lens 6. In the present embodiment, the laser light source module 3 generates green laser light. More specifically, the laser light source module 3 includes a laser diode 32 and a wavelength conversion optical element 34. In the present embodiment, the wavelength conversion optical element 34 is made of an SHG crystal for converting the wavelength of laser light having a wavelength of 808 nm into laser light having a wavelength of 532 nm (green).

  The collimator lens 5 is for collimating the light emitted from the laser light source module 3 and converting it into parallel light. The rod lens 6 is provided on the optical axis of the collimator lens 5 and transmits the collimator light from the collimator lens 5 to convert it into line light.

  A pulse oscillation circuit 4 is connected to the laser light source module 3. The pulse oscillation circuit 4 drives the laser diode 32 with a pulsed drive signal to cause the laser diode 32 to oscillate in pulses. The pulse oscillation circuit 4 controls the oscillation frequency and on-duty ratio of pulse oscillation. The blinking pulse light generated from the laser light source module 3 is converted into blinking line light by the collimator lens 5 and the rod lens 6.

An example of a schematic configuration of the pulse oscillation circuit 4 is shown in FIG.
The pulse oscillation circuit 4 includes a microcomputer 44, a power supply 47, a regulator 48, a mode switch 49, variable resistors 45 and 46, a transistor 42, and a resistor 43. The microcomputer 44 includes an input port 52, a CPU 54, a RAM 56, a ROM 58, and an output port 60. The input port 52, CPU 54, RAM 56, ROM 58, and output port 60 are connected to each other by a bus.

  The power supply 47 is connected to the microcomputer 44 and the laser diode 32 via a regulator 48. The regulator 48 is for supplying a predetermined stable voltage from the power supply 47 to the microcomputer 44 and the laser diode 32.

The output port 60 is connected to the base of the transistor 42 via the resistor 43. The transistor 42 is a switching element for driving the laser diode 32 on and off. The microcomputer 44 causes a pulsed drive current having a predetermined drive frequency and a predetermined on-duty ratio to flow from the output port 60 to the base of the transistor 42 via the resistor 43. The transistor 42 performs an on / off operation at the driving frequency and on-duty ratio, and applies a pulse current having the driving frequency and on-duty ratio to the laser diode 32. As a result, the laser diode 32 pulsates at the drive frequency and on-duty ratio. Here, if the pulse oscillation frequency is f (Hz), the time required for one cycle of operation is T (s), and the times of the on and off intervals of one cycle are P and Q, respectively, T = P + Q (1 ), F = 1 / T (2). On-duty ratio D is the ratio of on-time P to period T,
That is, it is defined as satisfying P = D · T = D · (1 / f) (3).

Next, a method for determining the apparent brightness of the line light based on the length measurement data will be described.
First, the distance L to the line light irradiation surface is measured using the length measuring device 100. Since the reference irradiation distance is Ls, the frequency and on-duty ratio at which the value on the vertical axis should be L / Ls in the graph of FIG. 7 are obtained from the graph. In the case of this embodiment, the reference irradiation distance is 5 m. For example, when the irradiation distance is 20 m, 20/5 = 4. Therefore, the frequency and on-duty ratio at which L / Ls is 4 are obtained in the chart of FIG. Here, a laser oscillation condition of an oscillation frequency of 40 Hz and an on-duty ratio of 80% or an oscillation frequency of 60 Hz and an on-duty ratio of 99% is applicable. Since the length of the line light at the irradiation distance of 20 m is four times longer than the length of the line light at the reference distance of 5 m, the area of the line light is also quadrupled. Here, since the laser power, which is the light source of the line light, always maintains a constant value, the light intensity density of the line light decreases to ¼ as the area is expanded four times. However, since the laser diode 32 can be turned on under the laser oscillation condition in which the apparent brightness is quadrupled by the above method, 1/4 × 4 = 1, and the apparent line light at the irradiation distance of 20 m is obtained. The brightness is comparable to the apparent brightness of the line light at the reference distance of 5 m. Similarly, when the irradiation distance is 15 m, 15/5 = 3. Therefore, the frequency and on-duty ratio at which L / Ls is 3 are obtained from FIG. In this case, (1) oscillation frequency 40 Hz, on-duty ratio 60% (2) oscillation frequency 55 Hz, on-duty ratio 70% (3) oscillation frequency 60 Hz, on-duty ratio 80% (4) oscillation frequency 70 Hz, on-duty ratio 99 % Laser oscillation conditions are applicable. Therefore, by oscillating the laser diode 32 under any one of the conditions (1) to (4), the apparent brightness of the line light at the irradiation distance 15 m is the same as the apparent brightness of the line light at the quasi distance 5 m. It becomes possible to be about.

  In FIG. 7, when the laser diode 32 is pulse-oscillated at an oscillation frequency lower than 40 Hz, flickering is felt, and data at a frequency lower than 40 Hz is omitted.

  The process from collecting measurement data L of the irradiation distance using the length measuring device 100 and irradiating the line light with the brightness of the line light corresponding to the irradiation distance will be described with reference to FIG. Measurement data L from the length measuring device 100 is taken into the microcomputer 44 through the input port 52 of the microcomputer 44. The ROM 58 stores in advance data on the laser oscillation conditions and the apparent brightness ratio of the irradiation light as shown in FIG. Assuming that the apparent brightness ratio of the irradiation light is Κn, there are several combinations of the laser drive frequency fnα and the on-duty ratio Dnβ corresponding to Κn. In view of this, the ROM 58 stores in advance various combinations of n and corresponding laser drive frequency fnα and on-duty ratio Dnβ. Next, the irradiation distance data L taken into the microcomputer 44 is processed in the CPU 54. Since the reference irradiation distance is Ls, the CPU 54 first calculates L / Ls. Next, data corresponding to Κn is selected from the combination data of the laser drive frequency fnα and the on-duty ratio Dnβ stored in the ROM 58 with Κn = L / Ls. Next, the laser diode 32 is pulse-oscillated with a combination of the driving frequency and the on-duty ratio. The RAM 56 temporarily stores data such as calculation results obtained while the CPU 54 is executing the laser oscillation program.

  The method for controlling the apparent brightness of the line light in the auto mode has been described. Next, a method for controlling the apparent brightness of the line light in the manual mode will be described.

  The mode switch 49 is a switch for the user to operate. The mode switch 49 is connected to the input port 52. The user can select one of three modes, that is, a short distance mode, a medium distance mode, and a long distance mode by operating the mode changeover switch 49.

When the laser marking device 1 is used in a situation where the line light irradiation distance is short, the light intensity per unit area of the line light is increased, so that the recognizability is improved and the visual recognition is facilitated. In this case, the user selects the short distance mode.
On the other hand, when used in a situation where the line light irradiation distance is long, the light intensity per unit area of the line light is reduced, the recognizability is lowered, and visual recognition is difficult. In this case, the middle and long distance mode is selected. In this embodiment, an irradiation distance of 0 m to less than 10 m is a short distance mode, a range of 10 m to less than 15 m is a medium distance mode, and a range of 15 m to less than 20 m is a long distance mode.
The ROM 58 stores in advance data of a combination of one drive frequency and one on-duty ratio D corresponding to each of the three modes.

More specifically, the ROM 58 stores one drive frequency f _n and one on-duty ratio D _n corresponding to the short distance mode.
In this example, the drive frequency f _n is 10 kHz, and the on-duty ratio D _n is set to 50%. Further, the ROM 58 stores one drive frequency f _f and one on-duty ratio D _f corresponding to the medium distance mode. The drive frequency f _f is one value within a range from 4 Hz to 80 Hz, and the on-duty ratio D _f is preferably set to one value within a range from 50% to less than 100%. In the present embodiment, the driving frequency is set to 60 Hz and the on-duty ratio is set to 70% in the medium distance mode. Even in the long distance mode, the driving frequency f _f is one value within a range from 4 Hz to 80 Hz, and the on-duty ratio D _f is preferably set to one value within a range from 50% to less than 100%. In the present embodiment, the driving frequency is set to 40 Hz and the on-duty ratio is set to 80% in the long distance mode.

  Next, a method for setting the drive frequency and the on-duty ratio in each mode will be described. The manufacturing operator of the laser marking device 1 performs a driving test of the laser light source module 3 and sets data before shipping the laser marking device 1 from the factory in the manufacturing stage of the laser marking device 1.

In this driving test, the manufacturer first repeats the laser light source module 3 while changing the driving frequency and the on-duty ratio to various values within the driving frequency range f _f and the on-duty ratio range D _f . Pulse drive. The manufacturing operator sets the drive frequency value and the on-duty ratio value determined to have the highest apparent brightness as the drive frequency range f _f and the on-duty ratio range D _f . The ROM 58 stores in advance a laser oscillation program which will be described later with reference to FIG. The CPU 54 executes the laser oscillation program to allow the user to select one desired mode, reads the corresponding combination of the drive frequency f and the on-duty ratio D from the ROM 58, and sets the laser diode 32 to the drive frequency and on-state. Pulse oscillation is performed with a combination of duty ratios.

  The RAM 56 temporarily stores data such as calculation results obtained while the CPU 54 is executing the laser oscillation program. The variable resistors 45 and 46 are connected to the input port 52. The user can finely adjust the on-duty ratio of the laser diode 32 by adjusting the resistance value of the variable resistor 45. The user can finely adjust the drive frequency of the laser diode 32 by adjusting the variable resistor 46.

Next, the laser oscillation operation will be described with reference to FIG.
First, when the power supply 47 is turned on (S0), the distance from the laser marking device 1 to the irradiation surface is immediately measured using the attached length measuring device 100 (S1). The measurement data L and the reference irradiation distance Ls are compared, and an L / Ls value is calculated (S2). Next, the apparent brightness ratio Κn = L / Ls, and the laser oscillation condition is selected (S3). Line light having optimum brightness is generated by oscillating the laser diode 32 under the selected conditions (S4). If the user wants to irradiate the line light by manual operation, the mode changeover switch 49 is turned on (YES in S5) to switch to the short distance mode by manual operation (S6). The CPU 54 sets the short distance mode in S6. The CPU 54 reads data of a combination of the driving frequency and the on-duty ratio facing the short distance mode from the ROM 58 and applies a pulse driving current of the combination of the driving frequency and the on-duty ratio to the transistor 42. As a result, the laser diode 32 pulsates with a combination of the driving frequency and the on-duty ratio. When mode switch 49 is switched (YES in S7), CPU 54 sets the intermediate distance mode (S8). The CPU 54 reads data of a combination of a driving frequency and an on-duty ratio corresponding to the medium distance mode from the ROM 58 and applies a pulse driving current of a combination of the driving frequency and the on-duty ratio to the transistor 42. As a result, the laser diode 32 pulsates with a combination of the driving frequency and the on-duty ratio. When mode switch 49 is further switched (YES in S9), CPU 54 sets the long distance mode (S10). The CPU 54 reads data of a combination of a driving frequency and an on-duty ratio corresponding to the long distance mode from the ROM 58 and applies a pulse driving current of a combination of the driving frequency and the on-duty ratio to the transistor 42. As a result, the laser diode 32 pulsates with a combination of the driving frequency and the on-duty ratio. When mode switch 49 is further switched (YES in S11), CPU 54 returns to the automatic irradiation mode again (S1) and repeats the operation described above. When the operation is to be ended, the CPU 54 makes a power on / off determination at each step of S12, S13, S14, and S15, and when it is turned off (YES at S12, S13, S14, and S15), the operation is ended.

  The laser light generation apparatus of the present invention can be widely applied not only to a line light generation optical system and a laser marking apparatus, but also to other apparatuses that use laser light. The line light generating optical system of the present invention can be widely applied not only to a laser marking device but also to other devices using line light.

1 is a schematic side view of a laser marking device according to an embodiment of the present invention. The schematic block diagram of the line light generation optical system which the laser marking apparatus of FIG. 1 mounts. FIG. 3 is a circuit diagram of a pulse oscillation circuit mounted on the line light generation optical system of FIG. 2. 4 is a flowchart of a laser oscillation operation executed by the pulse oscillation circuit of FIG. Explanatory drawing which shows the relationship between line light length and the distance from a laser marking device to an irradiation surface. Conceptual diagram showing the relationship between apparent brightness ratio of line light and laser oscillation conditions The figure which shows an example of the relationship between the apparent brightness ratio of line light, and a laser oscillation condition.

Explanation of symbols

1: laser marking device, 2: line light generation optical system, 3: laser light source module,
4: pulse oscillation circuit, 5: collimator lens, 6: rod lens, 11: support mechanism, 12: support frame, 13: large gimbal ring, 14: small gimbal ring, 15: mounting base, 16: case, 42: Transistor: 43: resistor, 44: microcomputer, 45, 46: variable resistor, 47: power supply, 48: regulator, 49: mode selector switch, 52: input port, 54: CPU, 56: RAM, 58: ROM, 60: Output port, 32: laser diode, 34: wavelength conversion optical element.

Claims (10)

A semiconductor laser, a switching element for driving the semiconductor laser on and off, a selection means for selecting one of a plurality of predetermined modes, a means for measuring the irradiation distance of laser light, and controlling the switching element, A control means for driving the semiconductor laser with a combination of a driving frequency and an on-duty ratio corresponding to the selected mode, and a combination of a driving frequency and an on-duty ratio corresponding to the laser beam irradiation distance measurement value A laser light generating apparatus comprising an operation / control means for driving the semiconductor laser. After the irradiation distance is automatically measured, auto data for driving the semiconductor laser based on the data is extracted from a storage unit in which a plurality of combination data of drive frequency and on-duty ratio, which are laser oscillation conditions, is stored in advance based on the measurement data. In correspondence with the irradiation mode and the plurality of predetermined modes on a one-to-one basis, the information processing apparatus further includes a storage unit that stores in advance data of a plurality of combinations of drive frequency and on-duty ratio, and the control unit includes the selection unit. The data of the combination of the driving frequency and the on-duty ratio corresponding to the selected mode is read from the storage unit, the switching element is controlled, and the semiconductor laser is controlled based on the read driving frequency and the on-duty ratio. It has a manual irradiation mode to drive, and auto irradiation mode and manual via the switching element Laser light emitting device according to claim 1, characterized in that to enable switching of illumination modes. The plurality of manual irradiation modes include a short-distance mode, a medium-distance mode, and a long-distance mode, and the storage unit has a combination of a driving frequency of 10 kHz and an on-duty ratio of 50% corresponding to the short-distance mode. Pre-stored, the storage unit corresponds to the medium distance mode and the long distance mode, one value of the driving frequency within the range of 4 Hz to 80 Hz, and one of the range of 50% to less than 100% 3. The laser light emitting device according to claim 2, wherein a combination of the value and the on-duty ratio is stored in advance. In the auto irradiation mode, the calculation unit calculates the apparent brightness ratio ラ イ ン n = L / Ls of the line light based on the measurement irradiation distance L and the reference irradiation distance Ls, and further calculates a ratio within a range of 4 Hz to 80 Hz. The combination of the driving frequency of one value and the on-duty ratio of one value within the range of 50% or more and less than 100% and the apparent brightness ratio Κn data when the line light is irradiated with the combination data in advance The value determined from L / Ls stored and calculated by the calculation / control means is set as Κn, and the semiconductor laser is based on the optimum combination data of the driving frequency and the on-duty ratio stored in the storage unit corresponding to Κn. The laser light emitting device according to claim 3, wherein the laser light emitting device is driven. The selection means includes an operation member, and when the user operates the operation member, the plurality of predetermined modes such as an automatic irradiation mode, a manual irradiation mode, and a short-distance mode and a medium-distance mode in the manual irradiation mode. 2. The laser beam generator according to claim 1, wherein a desired one of the long distance modes is selected. 6. The laser light generating apparatus according to claim 5, wherein the control means includes an adjustment member, and the user adjusts the drive frequency and on-duty ratio of the switching element by adjusting the adjustment member. 7. The laser beam according to claim 6, wherein the distance measuring means is an optical distance measuring device or an ultrasonic distance measuring device, and optimizes a driving frequency and an on-duty ratio corresponding to a measured value. Generator. 2. The laser beam generator according to claim 1, further comprising a wavelength conversion element that converts the wavelength of the laser beam output from the semiconductor laser into a wavelength of 532 nm. A line light generating optical system comprising: a collimating lens that converts a light beam emitted from the laser light emitting device according to claim 1 into collimated light; and a rod lens that converts collimated light into line light. . A laser marking device comprising a support mechanism for supporting the line light generating optical system according to claim 9.

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