JPH0239089A - Display - Google Patents

Abstract

PURPOSE:To obtain a write optical system which hardly receives an external adverse effect and in which an adjustment is unnecessary or easy by providing a subscanning mechanism part. CONSTITUTION:A laser output means itself is position-moved in a main scanning direction and a subscanning direction related to a liquid crystal element 6, the liquid crystal 6 surface is main/subscanned by a output laser beam, and an aimed display information pattern is write-processed. For example, by controlling the laser output from a laser diode 1 with the drive of a laser driver and main/subscanning movement related to the liquid crystal element 6 of the laser diode 1 with first and second moving means mechanism 22, 23-25 under a prescribed synchronizing relation, a liquid crystal element back surface is scanned by the laser beam, and the aimed display information pattern is written. The write pattern is enlarge-projected and displayed on a screen surface by a projection optical system. Thus, the write optical system can be obtained which hardly receives the external adverse effect and in which the adjustment is unnecessary or easy.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a display device, more specifically, a liquid crystal element is used as an information display medium, and a target display information pattern is written by scanning the surface of the liquid crystal element with a laser beam. The present invention relates to a display device using a processing method.

(Prior Art) Figures 3 and 4 are schematic configuration diagrams of a specific example of the above-mentioned display device (monochrome type liquid crystal projection type enlarged display device). The apparatus is roughly divided into a writing optical system and a projection optical system (reading optical system), and FIG. 3 is a perspective view of the writing optical system A, and FIG. 4 is a schematic diagram of the configuration of the projection optical system B. .

In the figure, 6 is a liquid crystal element as an information display medium, and the one in this example is a thin plate-like element (6) using smectic liquid crystal.
size (for example, several centimeters square). A writing optical system A is located behind the liquid crystal element 6 on the back side of the element.
A projection optical system B is arranged in front of the front side.

In the writing optical system A, a semiconductor laser (laser diode) 1 serves as a laser output means, and is driven by a control circuit (not shown) to output a laser beam 12 . The output laser beam is aligned by a collimator lens 2, subjected to beam direction control by an X-axis angle galvanometer mirror 3 and a Y-axis galvanometer mirror 4, and focused onto the back surface of a liquid crystal element 6 through a writing lens 5. The galvano mirrors 3 and 4 for the X-axis and around the Y-axis are controlled by drive devices 3a and 4a, respectively, which are controlled by a control circuit (not shown) to control the reciprocating rotational direction and rotational angular velocity in response to one display information pattern. As a result, the back surface of the liquid crystal layer f-6 is subjected to vector scanning exposure by a laser beam corresponding to the intended display information pattern. That is, the liquid crystal element 6 is subjected to a writing process 12' corresponding to the intended display information pattern using the laser beam 12 by the writing optical system A on the back side thereof.

In the liquid crystal element (this example is an element using smectic liquid crystal) 6, the liquid crystal in the area hit by the laser beam 12 becomes a liquid state due to beam irradiation and heating, and as it cools, the arrangement of molecules is disordered and light is scattered. Therefore, the non-heated part that was not hit by the laser beam is transparent, and in contrast to this non-written transparent part, the part that was hit by the laser beam and became in a light scattering state appears as an old pattern on the surface of the liquid crystal element 6. .

In the projection optical system B (FIG. 4), 8 is a projection light source such as a xenon lamp, and the light from this light source is focused by a condenser lens 9 and reflected by a mirror 10 toward the surface fil+ of the liquid crystal element 6. , the entire surface of the liquid crystal element 6 is irradiated. Then, the reflected light of the liquid crystal element surface of the irradiated light is focused by the projection lenses 11 at a position avoiding the reflection mirror 10 of the irradiated light, and is then enlarged and imaged on the screen 7 surface.

That is, by performing the writing process 12' of the target display information pattern on the surface of the liquid crystal element 6 using the laser beam 12 by the writing optical system A as described above, the light scattering δ indentation pattern appearing on the surface of the liquid crystal element is reflected by the projection optical system. The system B casts an enlarged shadow I2 on the screen 7, resulting in a display 75.

FIG. 5 shows a cross-sectional model diagram of the reflective liquid crystal element 6. As shown in FIG.

6a is the back of the element (III glass substrate, 6b is Cr2O3
Absorption film, 6C is Aj2 reflection film, 6d is smectic liquid crystal layer, 6e is transparent electrode, 6f is glass substrate on the front side of the element, 6
g is a power supply device that applies a voltage between the A11 reflective film and the transparent electrode 6e, and can be switched between high voltage and low voltage.

The state of the liquid crystal 6d changes as follows. Initially, when a high voltage is applied by the power supply device 6g while writing a figure, the liquid crystal 6d becomes transparent, and the projected light is completely reflected by the A1 reflection 11i 6 g and is not absorbed. Next, the figure [! 7, when writing is started, the application of voltage by the power supply device 6g is interrupted. The part hit by the laser beam 12 becomes a liquid state due to heat, but when it cools down, it becomes a scattering state, and the projected light is scattered at that part, so that the part inscribed by δ appears as a figure. If it is desired to partially erase a figure after it has been written, the laser beam 12 is irradiated on that area to make it into a liquid state, and when a low voltage is applied thereto, it becomes transparent and the figure is erased.

Like the above-mentioned display device, a system and configuration in which the display information pattern is written on the liquid crystal element 6 by laser beam scanning by vector scanning using two galvano mirrors 3 and 4 around the X-axis and Y-axis are as follows: Items where the written display information pattern consists of many lines, such as drawings,
In the case of so-called line drawings, it is advantageous because it is fast and fast.

The writing display information pattern fills in/fills out the area (f
In the case of a so-called image, rask scanning is much faster and more advantageous than vector scanning in writing to the liquid crystal element.

It is also possible to perform rask scanning writing using a galvanometer mirror. However, in this case, only the X-axis mirror 3 performs reciprocating rotational movement, so in terms of operating time, the other Y-axis mirror 3
It is significantly longer than the shaft mirror 4, which poses a problem in the durability of the drive system, and it is also slow and inefficient.

In addition to the X-axis circumferential galvano mirror 3, a rotating polyhedral mirror (so-called polygon mirror) dedicated to rask scanning is installed, and when writing line drawings, two galvano mirrors, one for Y-axis and one for Y-axis, perform vector scanning writing, and image At the time of writing, it is conceivable to switch the X-axis circumferential galvano mirror 3 to a rotating polyhedral mirror to perform rask scanning writing, but this would increase the number of parts and complicate control, making it uneconomical.

(Problems to be Solved by the Invention) In any case, the writing optical system using a galvano mirror has the following problems.

1. The galvanometer mirror mechanism is a delicate mechanism, and its adjustment requires a lot of effort.It is susceptible to vibrations, etc., and when movement is involved, additional adjustment is required, which limits the movement of the device. accompanies.

2. Since the use of moving parts such as galvanometer mirrors has a significant effect on the reliability of the entire device, it is better to have as few moving parts as possible. Therefore, two galvanometer mirrors 3 are required as shown in the example device in Figures 3 and 4 described above.
・Things that use 4 will cause a significant drop in reliability.

In view of the above-mentioned problems, the present invention requires delicate adjustment of the writing optical system of this type of display device.
Instead of using a galvano mirror mechanism that is susceptible to external adverse effects such as vibration and has many restrictions, it uses easy-to-handle parts to create a writing optical system that is less susceptible to external adverse effects and requires no or easy adjustment, resulting in high reliability and ease of use. The purpose of the present invention is to provide a display device with improved performance.

(Means for Solving the Problems) The present invention is a display device in which a target display information pattern is written and processed by scanning the surface of a liquid crystal element as an information display medium with a laser beam using an old optical system. The writing optical system includes a laser output means that is driven by a laser driver and outputs a laser beam modulated in accordance with a time series electrical pixel signal of a target display information pattern, and an output laser from the laser output means that is connected to a liquid crystal element. An optical element that guides and focuses light on a surface, and a laser that moves the laser output means in the production direction and the sub-scanning direction with respect to the liquid crystal element surface to perform main and sub-scanning on the liquid crystal element surface with the output laser from the laser output means. This is a display device characterized by comprising an output means and a main and sub-moving means.

(Function) That is, the device of the present invention moves the laser output means itself in the main scanning direction and the sub-scanning direction with respect to the liquid crystal element surface, and performs the main and sub-scanning of the liquid crystal element surface with the output laser beam to write the desired display information pattern. This structure eliminates the galvano-mirror mechanism of the above problem, and the main and sub-moving means such as the laser output means are made of easy-to-handle parts, making it less susceptible to external adverse effects and having a mechanical structure that does not require adjustment or is easy to adjust. Therefore, it is possible to obtain this type of display device that is highly reliable and easy to handle.

(Embodiments) Embodiment 1 FIG. 1(a) is a schematic diagram of the configuration of a display device according to an embodiment of the present invention, and FIG. 1(b) is a side view of the sub-scanning mechanism. Components and portions common to those of the third and fourth example devices described above are given the same reference numerals and repeated explanations will be omitted.

In the figure, 26 is a carriage, and this carriage includes a laser unit 21 in which the laser diode 1 as a laser output means and a laser driver are integrated, and the laser unit 21 is connected to the main scanning direction X with respect to the liquid crystal element 6 surface.
-X is equipped with a first moving means mechanism 22 that reciprocates.

Reference numerals 23, 24, and 25 designate a second moving means mechanism for reciprocating the carriage 26 itself in the sub-scanning direction YY with respect to the liquid crystal element surface 6.

In this embodiment, the first moving means mechanism 22 that reciprocates the laser unit 21 in the main scanning direction XX is composed of a stepping motor that is controlled to rotate in forward and reverse directions and a reciprocating lever. Since the reciprocating motion as the main scanning essentially draws an arc, a Stellar Dong motor or the like can be used as the driving means.

In this embodiment, the second moving means mechanisms 23, 24, and 25 for reciprocating the carriage 26 in the sub-scanning direction Y-Y are driven by a stepping motor 23 that is controlled to rotate in forward and reverse directions, and the rotation axis of the motor is the lead. A nut member 25 is screwed onto the lead screw shaft 24, and a carriage 26 is integrally attached to the nut member.

The nut member 25 and therefore the carriage 26 are reciprocated along the shaft 24 by rotating the motor 23 and thus the f424 in forward and reverse directions. That is, it is moved back and forth in the sub-scanning direction Y-Y. The carriage 26 is prevented from rotating or swinging about the shaft 24 during the reciprocating process by a rotation preventing member (not shown).

Reciprocating movement of the laser unit 21 in the main scanning direction XX by the first moving means mechanism 22 and the second moving means mechanism v42
Sub-scanning direction Y- of the carriage 26 by 3, 24, 25
The reciprocating movement in Y corresponds to the main and sub-scanning movement of the laser diode 1 as the laser output means of the laser unit 21 with respect to the surface of the liquid crystal element 6.

A laser diode 1 serving as a laser output is driven by a laser driver to output a laser beam 12 modulated in accordance with time-series electrical pixel signals of a target display information pattern. The output laser beam is aligned by a collimator lens 2, directed toward the back surface of the liquid crystal element 6 by a folding mirror 20, and focused on the back surface of the liquid crystal element through a writing lens 5.

The main control unit (not shown) controls the laser output from the laser diode 1 by driving the laser driver and the liquid crystal element (smectic type) 6 of the laser diode 1 by the first and second moving means mechanisms 22, 23 to 25. By controlling the main and sub-scanning movements under a predetermined synchronization relationship, the back surface of the liquid crystal element is scanned with a laser beam and a desired display information pattern is written. Then, the written pattern is enlarged and projected onto the screen (7) by the projection optical system B (same configuration as the example in FIG. 4) and displayed.

Embodiment 2 In the first embodiment, the first moving mechanism for reciprocating the laser unit 21 in the main scanning direction x-x is composed of a stepping motor and a reciprocating lever 22.
If the liquid crystal element 6 is moved along an arcuate trajectory, or if the liquid crystal element 6 is small in size, about several centimeters square, the arcuate trajectory will be short and it may be equivalently moved back and forth along a straight line trajectory. In this case, the first moving means mechanism can be a linear motor that performs linear motion, or a linear motion mechanism that uses a belt or wire.

In FIG. 2(a), a linear motor 27 consisting of a stator 27a and a movable element 27b and driven to reciprocate along a line 1a in the main running direction xx is mounted on a carriage 26, and a laser beam is attached to the movable element 27b of the motor. An example is shown in which the unit 21 is mounted and supported. The laser unit 21, that is, the laser diode 1 as a laser output means, which is not dependent on the reciprocating drive of the movable element 27b, is linearly reciprocated in the main scanning direction XX with respect to the liquid crystal element surface.

Embodiment 3 In FIG. 2(b), a drive pulley 29 and a turn pulley 30, which are rotated in the forward and reverse directions by a forward and reverse motor, are provided on the carriage 26.
A wire 28 is stretched between both pulleys 29 and 30,
A laser unit 21 is coupled to the wire 28, and the reciprocating tensile force of the wire 28 caused by driving the drive pulley 29 in forward and reverse rotation causes the laser unit 21, that is, the laser diode 1 as a laser output means, to be It is linearly reciprocated in the scanning direction XX.

This configuration has a large cost reduction effect when constructing a compact and inexpensive display device.

Embodiment 4 FIG. 2(c) shows the above-mentioned embodiment 1 as the first moving means mechanism.
An example is shown in which a lead screw mechanism similar to the second moving means mechanisms 23 to 25 (FIG. 1(b)) is adopted.

That is, 31 uses a Stellar Dong motor that is controlled to rotate in forward and reverse directions as a driving means, the rotary shaft 32 of the motor is a lead screw shaft, a nut member 33 is screwed onto the lead screw shaft, and the laser unit 21 is attached to the nut member. It is installed in one piece. When the shaft 32 is rotated forward and backward according to the motor 31, the nut member 33 and therefore the laser unit 21
is reciprocated along the axis 32 in the main scanning direction XX.

Constructing both the first and second moving means mechanisms for moving the laser diode 1 as a laser output means in the main and sub-scanning directions using the Stellar Dong motor as described above does not require particularly high resolution and is simple. - Effective in constructing an inexpensive display device.

(Effects of the Invention) As described above, according to the present invention, the writing optical system of this type of display device is a galvano mirror mechanism that requires delicate adjustment and is susceptible to external adverse effects such as vibration and has many restrictions. It is possible to construct a writing optical system that does not require or is easily adjusted and is free from external adverse influences using easily handled components, thereby obtaining a display device that is highly reliable and easy to handle.

Moreover, since there are no more restrictions on what was previously limited to use in fixed locations, it is now possible to display large screens anytime and anywhere depending on the situation.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic diagram (plan view) of the configuration of a display device according to an embodiment of the present invention, FIG. 1(b) is a side view of the sub-scanning mechanism, and FIGS. ) are schematic diagrams of the main parts of the apparatuses of the second to fourth embodiments, FIG. 3 is a perspective view schematically showing the construction of the writing optical system part of the conventional apparatus, and FIG. 4 is a schematic diagram of the construction of the projection optical system part. FIG. 5 is a cross-sectional model diagram of a liquid crystal element. A is a writing optical system, B is a projection optical system, 1 is a laser diode, 21 is a laser unit, 6 is a liquid crystal element, 7 is a screen, 26 is a carriage, 22.27.28.29
- 30. 31, 32, and 33 are first (for main scanning) moving means mechanisms, and 23, 24, and 25 are second (for sub-scanning) moving means mechanisms.

Claims (1)

[Claims] (1) A display device that writes a desired display information pattern by scanning a liquid crystal element surface as an information display medium with a laser beam using a writing optical system, and the writing optical system is driven by a laser driver to write a desired display information pattern. a laser output device that outputs a laser beam modulated in accordance with a time-series electric pixel signal of a display information pattern; an optical element that guides and focuses the output laser from the laser output device onto a liquid crystal element surface; The laser output means includes main and sub-moving means for moving the laser output means in the main scanning direction and the sub-scanning direction with respect to the liquid crystal element surface to scan the liquid crystal element surface with the output laser from the laser output means. A display device characterized by: