JPS627018A - Reflective concentrator - Google Patents

Abstract

PURPOSE:To change the condensing state of reflected light flux by arranging many fine vibrating reflection mirrors to be individually vibrated on a reflection base board and changing the inclination of the reflection mirrors. CONSTITUTION:Laser light radiated from a laser diode 27 is converted into parallel light by a collimater lens 28 and the parallel light is made incident upon a semi-spherical condensing device 19 on which the vibrating reflection mirrors are arranged. The reflected light path of the light made incident upon the device 19 is controlled by inclining the many vibrating mirrors arranged spherically on the device 19 and the incident light is reflected in the prism direction as condensed light, its optical path is refracted by the prism 31 and converged into a focus surface 32. The reflected light from the focus surface 32 is made incident upon a photoelectric sensor 29, the converged state of light on the focus surface 32 is detected by the sensor 29 and a signal outputted from the sensor 29 is fed back to the condensing device 19. Consequently, the inclined angles of respective vibrating mirrors can be controlled, the converged state of light can be continuously controlled and complex parts such as a lens driving mechanism can be omitted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses an electromechanical transducer in which a minute mirror swings, and works in the same way as a condenser lens to condense light. This relates to optical devices.

[Conventional technology]

Traditionally, condensing devices have been used as optical systems that simply collect light, but in recent years, as optical information processing using Redebeam light has been put into practical use, the precision required of condensing devices has also increased. It's coming. Traditional light concentrators use lenses,
In order to displace the light condensing position on the optical axis, or the focal point, it is necessary to drive the lens itself.

FIG. 6 shows an optical pickup device using the above-mentioned light condensing device. In the same figure, the luminous flux generated from the laser diode rlooo is collimated by the collimator lens 1.
01, the light is made into parallel light, passes through a prism 102, and is focused onto a focal plane 104 by a condenser 103. The reflected light from the focal plane 104 is reflected by the prism 102,
The light is focused onto a light sensor 106 by a sensor lens 105 . The optical sensor 106 detects the focused state of the focal plane 104, and the lens driving mechanism 103' of the light collecting device 103 drives the light collecting device 103 to adjust the focus. Such a condensing device can perform sophisticated control of the light beam condensed onto the focal plane 104.

However, the focusing device as shown in FIG. 6 requires a lens drive mechanism 103', and this device 103' has the disadvantage that it is difficult to miniaturize the focusing device.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reflective condensing device that can change the condensing state without the need for lenses and lens driving devices used in conventional condensing devices.

[Summary of the invention]

The above purpose is to manufacture a reflective type light condensing device by arranging a large number of fine oscillating reflection mirrors 2-, which can be oscillated individually, on a reflection base, such as the electromechanical transducer described later. This is achieved by changing the inclination of the reflecting mirror according to the position on the reflecting base and the focusing characteristics of the light beam to be focused, thereby changing the focusing state of the reflected light beam.

〔Example〕

An embodiment of the present invention will be described below. First, an electromechanical transducer in which a minute mirror oscillates based on the same principle as the light condensing device of the present invention will be described.

FIG. 4 shows a sectional view of a swinging mirror of such an electromechanical transducer. In the same figure, 1 is a mirror and A
It is made of materials such as I and Ag and serves to reflect incident light. A substrate 2 supports the mirror 1 and is made of Au. 3 and 4 are support members for 1 and 2, 3 is called a mirror contact and is used to receive a rib part that performs an electromechanical operation, and 4 is an insulating member. 5 is a *6Fi air gap which is a 4-resilicon r-t and plays the role of FET MO8) run sister group). 7 has a 70-ting field rate, and a voltage is applied to the floating field plate of 7 from the N+70-tinguance of 8 based on the ON/OFF information of the transistor. 9 indicates the N+ drain, which is also an MO8 type FET
) serves as a configuration of runcisisters, -. 10 is dirt oxide, and 11 is a P-type silicon substrate. Figure 4 (b
) is a view seen from the entrance direction of FIG. 4(a), in which 12 is an air gap, 13 is a part of the mirror that swings electromechanically, and 14 is a bow part. 15 is a part of the surface mirror other than the swinging mirror. These are manufactured using processes similar to IC or LSI processes.

FIG. 5 shows an electrical equivalent diagram of the element shown in FIG.
16 indicates the voltage vM applied to the mirrors 1 and 2 and the support member. 17 indicates the voltage V applied to 8K. 18 shows the transistor configuration, and V, depending on the ON and OFF of the D (drain) signal 9 and the G (f-) signal 5,
The voltage is turned on and off at 8. At this time 1, 2
Voltage vM is applied to j5. A potential difference is turned on between 1.2 and 8.
, is increased or decreased by the OFF signal. At this time, depending on the potential difference, a force F according to the following equation is generated during 6.7.

F ch KV" (K: constant, ■=potential difference, α: constant,
F: Bending force) Mirrors 1 and 2 bend at the hinge portion 14 due to force F.
It is swayed by. In Fig. 4(a), the left mirror bends from the base when there is a large voltage difference between 1.2 and 8, and due to this action, the incident light is twice the deflection angle of the mirror. It is reflected at a different angle. On the other hand, when the voltage difference is small, like the right mirror in FIG. 4(a), a portion of the mirrors 1 and 2 are not bent due to the small force exerted by 7). Therefore, the incident light is reflected without touching the mirror.

FIG. 1 shows a schematic diagram of a condensing device of the present invention using the above-mentioned swinging mirror. In the same figure, the light condensing device 19
is made of a structure in which swinging reflecting mirrors are arranged on the entire surface in the circumferential direction on a semicircular reflecting base 20. Reference numerals 21 to 26 indicate a radial row of reflecting mirrors. According to the condensing device 19 of the present invention, the angle of deflection of each swing-reflecting mirror is adjusted according to the arrangement position of the reflection base 20 and according to the condensing characteristics of the light beam to be condensed. , it is possible to continuously change the condensing state of reflected light.

FIG. 2 shows a schematic diagram of an optical pickup device using a light condensing device 19. In the figure, a laser beam generated by a radar diode 27 is converted into parallel light by a collimator lens 2B, and is incident on a semicircular condenser 19 provided with a swinging reflecting mirror. Here, the condensing device 19 is 45° with respect to the incident light in the normal direction of the spherical surface.
It is installed in the direction of The reflected light path of the light incident on the condensing device 19 is controlled by tilting a large number of swinging mirrors arranged in a spherical shape according to the above-mentioned principle, and the light is reflected toward the prism as condensed light. Ru. The light entering from the condensing device 19 has its optical path bent by the prism 31 and is condensed onto three target focal planes. Further, the reflected light from the focal plane 32 passes through the prism 31 again, is condensed by the condenser lens 30, and enters the photoelectric sensor 29.

By the light incident on the photoelectric sensor 29, the condensation state of the light at the focal plane 32 is detected, and the signal from the sensor 29 is
Feedback to the light condensing device 19 makes it possible to continuously control the light condensing state, and as a result, complicated parts such as the lens drive mechanism 103' shown in FIG. 6 become unnecessary.

FIG. 3 shows a control circuit for the light condensing device 19. In the figure, the photoelectric sensor 29 outputs a signal indicating the state of light condensation on the condensing surface 32, and the control circuit 33 processes the signal to control the tilt angle of each swinging mirror of the condenser 19. A signal is output. The signal from the control circuit 33 is amplified by the driver circuit 34 and transmitted to each swinging mirror of the condensing device 19 to control the mirror inclination angle and change the condensed state at the focal plane 32. becomes possible. Note that in the figure, 35 is a power supply circuit for the driver circuit 34.

The light condensing device 19 of the present invention is not limited to the embodiment described above, and various modifications are possible.

For example, the shape of the reflection base 20 of the condensing device 19 is not limited to the semicircular shape as shown in FIG.

Further, the individual sizes of the swinging reflection mirrors may be changed depending on the part of the condensing device 19. Furthermore, from the viewpoint of optical characteristics, it is also conceivable to increase or decrease the number of swinging mirrors depending on the position on the reflection base 20.

Furthermore, although the optical pickup device has been described as an example of the use of the light condensing device 19, it is clear that it can be widely applied as a condensing device for other optical systems.

〔Effect of the invention〕

As explained above, according to the light condensing device of the present invention, a simple optical system can be used in place of a conventional light condensing device that requires a complicated mechanism, and the optical system can be made smaller and lighter. It has become possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a light condensing device of the present invention, and FIG. 2 is a schematic diagram showing an example of a light pickup using the above-mentioned light concentrating device. FIG. 3 is a block diagram of the control circuit of the light condensing device. FIG. 4 and FIG. 5 are diagrams for explaining the same electromechanical transducer as the driving principle of the light condensing device of the present invention, respectively. FIG. 6 is a schematic diagram showing an optical big-ag using a conventional condensing device. 19: Light condensing device, 20: Reflection base.

Claims (1)

[Claims] (1) A large number of minute oscillating reflecting mirrors that can be oscillated individually are arranged on a reflecting base, and by changing the inclination of the reflecting mirrors, the condensing state of the reflected light beam can be changed. Reflective concentrator.