JPS63180123A - Input device - Google Patents

Abstract

PURPOSE:To draw pictures with high operability and in the same operating sense same as that of an ordinary writing tool by providing a switch which detects the contact state of a pen point onto the surface of a liquid crystal panel in addition to a semiconductor laser, a converging lens, etc. CONSTITUTION:When pictures are drawn onto a liquid crystal panel 2, a light pen 9 is brought into contact with the surface of the panel 2 via its tip. Since a switch 17 is turned on, a semiconductor laser 11 is turned on at a circuit part 14. The characteristics of a material 8, e.g., the smetic liquid crystal are changed by a heating system by irradiation of the laser beam to draw the pictures. When the tip of the pen 9 is removed from the panel 2, the switch 17 is turned off and the laser beam 11 is also turned off. Then the picture drawing actions are stopped. As a result, the pictures are drawn along the contact locus of the tip of the pen 9 in the same operating sense as an ordinary writing tool.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention includes a display panel using a liquid crystal or the like that is writable and has a display function, and also has the function of inputting information to an external device such as a computer. , relates to a so-called tablet/display panel type input device.

Conventional technology Conventionally, for example, a thermal writing type liquid crystal display device using liquid crystal,
This is shown as a conventional example in Japanese Patent Laid-Open No. 59-34.587. This basically consists of a display panel in which transparent electrodes are formed on the opposing inner surfaces of two glass substrates, and smectic liquid crystal is sealed between the glass substrates. Therefore, for example, a gas laser such as Ar is focused on such a display panel to increase the temperature of the smectic liquid crystal in the display portion, and temporarily transform it into an isotropic liquid phase. Thereafter, when the laser beam is removed and the liquid crystal is rapidly cooled to a smectic phase, the alignment direction of the liquid crystal molecules is disturbed and a region exhibiting strong scattering properties is generated. This area becomes visible as an image, and any image can be written or displayed. According to this,
As an output device, an image can be displayed on a display panel based on image data, and an image can also be written and displayed on the display panel using a light pen or the like.

In the above-mentioned publication, in such a display panel,
We focused on the fact that the orientation of liquid crystal molecules is different between the initial state (non-written state) and the written state (that is, the dielectric constant is different between the cloudy part and the transparent part), and the capacitance between the electrodes that sandwich the liquid crystal layer is different. The displayed image can then be read and input into a computer or the like. In other words, by utilizing the fact that a cloudy area and a transparent area can be formed in the liquid crystal layer of a display panel by heat-electric field writing of smectic liquid crystal, image data additionally written with a light pen or the like can be read by changing the dielectric constant. It has been made possible.

Problems to be Solved by the Invention However, even if the image signal written on the display panel, specifically the liquid crystal display panel, can be output to an external device, the premise is that Additional writing to the display panel is inconvenient. For example, such writing is performed using a light pen as shown in FIG. 17 of the above-mentioned publication. This device has a built-in gas laser, polarization modulator, etc., but it is difficult to control the laser light during writing (turning the gas laser source on and off, etc.), and it feels like writing with a pencil or pen. Writing is difficult.

Means for Solving the Problems A pair of substrates are formed with electrodes facing each other on opposing surfaces, and the substrates are held between the substrates and are heated to change the scattering state, light transmittance, light absorption rate, etc. An input device including a display panel made of a substance whose physical properties change to display an image, comprising a semiconductor laser, a condenser lens that focuses laser light from the semiconductor laser onto the display panel, and the display panel. A light pen is provided, which includes a switch that detects contact of the pen tip on a panel surface, and a circuit section that lights up the semiconductor laser when the switch is turned on.

Operation When the tip of the light pen is in contact with the display panel surface, the semiconductor laser also lights up when the switch is turned on.
A written state is achieved by heating the substance by condensing laser light irradiation. On the other hand, when the light pen is removed from the display panel surface, the switch is turned off and the semiconductor laser is also turned off, resulting in a non-writing state. In other words, writing is performed only when the light pen is in contact with the display panel surface, and this is equivalent to the feeling of writing with a writing instrument such as a pencil or pen.

Example An embodiment of the present invention will be described based on the drawings.

First, an outline of the input device of this embodiment is shown in FIG.

First, a display panel 2 of a predetermined area that also serves as a tablet is provided on the top surface of a keyboard-shaped housing 1, and several input keys 3 are provided below the display panel 2.

Here, various configurations can be adopted as the display panel 2.

Generally, it is composed of liquid crystal. For example, as shown in FIG. 3, a pair of substrates 4 and 5 made of glass substrates or the like are provided facing each other, and transparent electrodes 6° 7 facing each other are formed on the opposing surfaces of these substrates 4 and 5. . More specifically, these transparent electrodes 6 and 7 are formed in stripes in the x and y directions so that the opposing portions constitute a matrix wiring circuit as a whole. In other words, each opposing portion of these transparent electrodes 6 and 7 corresponds to each image dot.

Between the pair of substrates 4 and 5 is a material 8 whose physical properties such as scattering state, light transmittance, light absorption rate, or dielectric constant change by applying heat or heat and an electric field, here, for example, a smectic liquid crystal. is included. If the substance is a smectic liquid crystal, as shown in JP-A-59-34587, for example, it exhibits a smectic A phase at room temperature, transitions from the smectic A phase to a nematic phase at 42°C, and further exhibits a smectic A phase at 42°C. A material that transitions from a nematic phase to an isotropic liquid phase at ℃ is used. In this case, the interface is treated with a silane-based surfactant, and in the initial state, the smectic liquid crystal molecules are set to be oriented perpendicularly to the substrates 4 and 5 (although they may also be oriented horizontally).

When outputting and displaying an image in the display panel 2 in which such a smectic liquid crystal substance 8 is sealed, the energization state of the matrix-wired electrodes 6 and 7 is controlled in a line-sequential manner by heating and cooling. It will be done. For example, according to FIG. 3, the power supply side switch S1 and the grounding side switch S2 for the electrode 5 in the X direction are sequentially turned on to perform energization and heating, while the switch S3 for the electrode 6 in the Y direction is turned on during the cooling process. In other words, depending on whether an electric field is applied or not, the dielectric constant of the substance 8 in each image dot portion facing each other is changed by the electrodes 6 and 7, thereby selectively forming a cloudy state and a transparent state. will be displayed as a dot.

This is not limited to the case where the substance 8 sealed between the substrates 4 and 5 is smectic liquid crystal. For example, even if a material coated with a vinylidene fluoride copolymer and an acrylic acid ester copolymer is used as substance 8, by speeding up or slowing down the cooling process after heating for each dot, A cloudy part and a transparent part are formed, and the image can be displayed as dots. In short, it is sufficient to encapsulate a substance whose physical properties can be changed by heating such as laser beam irradiation to display an image.

Using such a display panel 2 as an input tablet,
To read the image displayed on the display panel 2 (such as an image written with a light pen described later), switch S,...
Turn on S sequentially and measure the capacitance of each dot.
The written part and the non-written part are read because the dielectric constant is different.

This is similar to the method disclosed in Japanese Patent Laid-Open No. 59-34587 mentioned above. In other words, the space between the opposing electrodes 6 and 7 can be regarded as a capacitor filled with the substance 8, and in the non-writing state, the liquid crystal molecules are oriented perpendicularly to the electrodes, and the dielectric constant of this liquid crystal layer is This is because, while the dielectric constant is approximately equal to the dielectric constant in the long axis direction of the liquid crystal molecules, in the writing state, the dielectric constant changes as the alignment direction of the liquid crystal molecules is significantly disturbed. More specifically, the capacitance as a capacitor is smaller in the written state than in the non-written state. As a result, by electrically detecting the capacitance of each dot portion, the orientation state of the liquid crystal, that is, the written state and the non-written state can be distinguished.

However, the reading of the image written and displayed on the display panel 2 is not limited to the method using such changes in the dielectric constant of the smectic liquid crystal. good. This is because the image display on the liquid crystal panel 2 consists of cloudy areas and transparent areas, so even if the image displayed on the two sides of the liquid crystal panel is read line-by-line using differences in transmittance or reflectance, It's good. This situation is the same when substance 8 is a vinylidene fluoride copolymer and an acrylic acid ester copolymer.

A light pen 9 is provided on the display panel 2 for freely writing and writing images from the outside. This light pen 9 has a fountain pen-shaped pen housing 1o in appearance, as shown in FIG. Inside the pen housing 10, there is a semiconductor laser 11 for writing an image by condensing and heating a laser beam, and a collimator lens 12 for converting the laser beam emitted from the semiconductor laser 11 into a parallel beam. Condensing lenses 13 are arranged linearly in a predetermined positional relationship to emit a parallel light beam from the opening 10a of the pen housing 10 and to condense it onto the display panel 2 surface. That is, while the pen tip of the light pen 9 (the opening 10a of the pen housing 10) is in contact with the surface of the display panel 2, the laser beam from the semiconductor laser 11 is focused into the substance 8 by the condensing lens 13. is set to be

Further, inside the pen housing 10, a circuit section 14 is built in which the semiconductor laser 11 and the like are electrically connected, and a power supply, control circuit components, etc. are mounted.

Furthermore, the main power switch 1 as a penlight 9
5 is provided at the top with a bush switch structure, and at the bottom is a volume 16 for laser power adjustment that rotates the housing.
Also provided.

In the opening 10a of the pen housing 10, there is a switch 1 that detects the contact state on the liquid crystal panel 2 at the tip.
7 is provided. This switch 17 has a pair of electrode parts 19 that are normally separated by the urging force of a coil spring 18.
It consists of a, 19 b.

That is, the electrode part 19a side is fixedly arranged, and the electrode part 19b side is attached to the actuating contact member 20 which is urged outward by the coil spring 18. By bringing the pen tip into contact with the liquid crystal panel 2, , the actuating contact member 20 is the coil spring 1
8, the electrode portion 19b contacts the electrode portion 19a, that is, the switch 17 is turned on.

Such a switch 17 is connected to the power supply circuit of the semiconductor laser 11 in the circuit section 14, and is set to control on/off of the semiconductor laser 11.

According to such a light pen 9, when writing an image on the liquid crystal panel 2, it is sufficient to bring the pen tip into contact with the surface of the liquid crystal panel 2. As a result, the switch 17 is turned on, and the circuit unit 14 turns on the semiconductor laser 11 and changes the characteristics of the substance 8 by heating by laser beam irradiation, thereby realizing image writing. Then, if you separate the pen tip of the light pen 9 from the two LCD panels,
Since the switch 17 is turned off, the semiconductor laser 11 is also turned off, and no write operation is performed. Therefore, an image is written along the contact locus of the tip of the light pen 9. This is a writing method that has exactly the same feeling as writing images such as letters on paper with a writing instrument such as a general pencil or fountain pen, and is easy to operate without having to be particularly conscious of turning on and off the laser beam. Writing can be performed.

Effects of the Invention As described above, the present invention includes a semiconductor laser, a condensing lens, etc., as well as a switch that detects the state of contact of the pen tip on the liquid crystal panel surface and lights up the semiconductor laser only when there is contact through the circuit section. Therefore, when the pen tip touches the liquid crystal panel, it enters the writing state, and when the pen tip is released, it enters the non-writing state, so it is possible to easily write images with the same operating feeling as a regular writing instrument such as a fountain pen. It is possible.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a partially cutaway front view of a light pen, FIG. 2 is a schematic perspective view of the entire input device, and FIG. 3 is a diagram showing the configuration of the display panel. FIG. 2... Display panel, 4, 5... Board, 6.7...
Electrode, 8... Substance, 9... Light pen, 11...
Semiconductor laser, 13... Condensing lens, 14... Circuit section, 17... Switch, %, 3 replacement

Claims (1)

[Claims] A pair of substrates with electrodes formed on opposing surfaces, and a substance that is held between the pair of substrates and whose physical properties such as scattering state, light transmittance, and light absorption rate change due to heat to display an image. An input device including a display panel comprising: a semiconductor laser; a condenser lens that focuses laser light from the semiconductor laser onto the display panel; and a switch that detects contact of a pen tip with the surface of the display panel. and a circuit unit that lights up the semiconductor laser when the switch is turned on.