JPH0915726A - Overhead projector - Google Patents

Abstract

PURPOSE: To make it possible to project image data to a screen, etc., with an inexpensive structure by forming the image meeting image data on colorless drawing paper and projecting this image onto an image display section. CONSTITUTION: The colorless drawing paper 10 formed by laminating a coloring layer which is made transparent by adhesion of a colorless transparent liquid thereto and transparent sheet is moved in an arrow (a) direction by driving of a motor 12. The colorless transparent liquid is splashed from an ink jet head 13 in accordance with the image data inputted to an image data input device 15 from a floppy disk(FD) or an ID card to form the image on the colorless drawing paper 10. The driving of the motor 12 is stopped and the colorless drawing paper 10 is irradiated with the light from a light source 2 when the part formed with the image on the colorless drawing paper 10 moves to the space between original platen glass 6 and a Fresnel lens 4. The light transmitted through the transparent parts of the colorless drawing paper 10 is then projected onto the screen 9 and the image formed on the colorless drawing paper 10 is projected on the screen 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead projector.

[0002]

2. Description of the Related Art The general structure of a conventional general overhead projector will be outlined with reference to FIG. First, a light source 2, a condensing mirror 3 and a Fresnel lens 4 are provided in the main body case 1, and an OHP (overhead projector) sheet original in which an image is written on transparent paper is provided on the upper end surface of the main body case 1. A document table glass 6 on which the document 5 is placed is provided. Further, a projection lens 7 and a reflection mirror 8 are arranged above the document table glass 6. In such an overhead projector,
By placing the OHP sheet original 5 on the original platen glass 6 and irradiating it with light from the light source 2, the light transmitted through the OHP sheet original 5 is projected on the image display unit such as the screen 9, and the OHP sheet is displayed. The image written on the original 5 is displayed on the screen 9 or the like.

Further, a liquid crystal display panel is provided instead of the platen glass 6, image data created by a word processor or the like is written in an FD (floppy disk) or the like, and an image based on this image data is displayed on the liquid crystal display panel. An overhead projector has also been developed, which is designed to display the image displayed on the liquid crystal display panel on the screen 9 or the like.

[0004]

In the overhead projector of the type using the OHP sheet original 5, the OH
It takes a lot of time to create the P sheet document 5.

On the other hand, an overhead projector using a liquid crystal display panel makes it easy to prepare a document to be projected on the screen 9 or the like, but the entire apparatus becomes very expensive. Further, in an overhead projector using a liquid crystal display panel, it is not possible to project an image on the screen 9 or the like and start a presentation, and then write an additional image in the middle of the presentation and project it on the screen 9 or the like.

[0006]

An overhead projector according to a first aspect of the present invention is an overhead projector in which a colored layer and a transparent sheet, which are in a transparent state when a colorless and transparent liquid is attached, are laminated, and An image forming means for forming an image, a light source for irradiating the water writing paper with light, an image data input device for inputting image data of an image formed on the water writing paper, and an input for the image data input device. Control means for controlling the image forming means based on the image data.

An overhead projector according to a second aspect of the present invention is the overhead projector according to the first aspect of the invention, wherein the endless belt is formed in a loop shape and the brush paper and the transparent member are alternately arranged along the loop direction. And a moving means for moving the endless belt along the loop direction.

An overhead projector according to a third aspect of the present invention is the overhead projector according to the first aspect of the invention, wherein the brush paper is formed into a loop shape and the transparent sheet is color-coded into two or more colors along the loop direction.
A moving means for moving the brush paper along the loop direction is provided.

An overhead projector according to a fourth aspect of the invention is the overhead projector according to the first, second or third aspect of the invention, in which liquid coating means for coating the entire surface of the writing paper is provided, and a thermal head is used as an image forming means. Was set up.

[0010]

In the overhead projector according to the first aspect of the present invention, when the image data is input to the image data input device, the control means controls the image forming means based on the input image data, and the image forming means causes the ink brush. An image is formed on the paper. Then, by irradiating the portion of the writing paper on which the image is formed with light from a light source, the image formed on the writing paper is displayed on an image display unit such as a screen.

In the overhead projector according to the second aspect of the invention, the loop-shaped endless belt composed of the writing paper and the transparent member is moved by the moving means, and the portion of the writing paper on which the image is formed is irradiated with the light from the light source. The image is displayed on an image display unit such as a screen by moving the image to a position where the image is displayed. On the other hand, by moving the transparent member to a position where the light from the light source is irradiated and placing the OHP sheet original on the transparent member, the image written on the OHP sheet original is displayed on the image display unit such as a screen. It is projected.

In the overhead projector according to the third aspect of the present invention, since the transparent sheet of the writing paper is color-coded into two or more colors, an image is formed on a portion of the writing paper in which the color of the transparent sheet is different, so that a screen etc. The color of the image displayed on the image display section of changes.

In the overhead projector according to the fourth aspect of the present invention, the whole of the writing paper is made transparent by applying the liquid to the entire surface of the writing paper by the liquid applying means, and the writing paper in the transparent state is used as image data. An image can be formed on the writing paper by heating with a thermal head according to a corresponding pattern and evaporating the moisture in the heated portion.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. The same parts as those described in FIG. 7 are designated by the same reference numerals, and the description thereof will be omitted. FIG. 1 is a front view showing a schematic structure of an overhead projector. A brush paper 10 formed in a loop shape is housed in a main body case 1. The water brush paper 10 passes under a condenser mirror 3 and Further, it is arranged so as to pass between the Fresnel lens 4 and the platen glass 6. And this brush paper 10 is 4
It is held by individual holding rollers 11a, 11b, 11c and 11d, and the holding roller 11a is connected to a motor 12 which is a moving means for moving the above-mentioned brush paper 10 along the loop direction.

Further, in the main body case 1, an ink jet head 13 which is an image forming means for forming an image on the writing paper 10 and a heating roller 14 for erasing the image formed on the writing paper 10 are provided. It is provided. In addition,
The heating roller 14 is arranged between the original table glass 6 and the inkjet head 13 along the moving direction of the water brush paper 10 (direction of arrow a).

Next, an FD or ID card in which the image data of the image to be formed on the above-mentioned brush paper 10 is written is detachably inserted into this overhead projector and is written in these FD or ID card. Image data input device 15 having a function of reading existing image data
Is connected. Then, this image data input device 1
5 is connected with image data read from an FD or an ID card, and is connected with a head controller 16 which is a control means for controlling the ejection of the liquid from the inkjet head 13 based on the input image data. There is.

Here, the structure of the above-mentioned writing paper 10 and the principle of forming an image by the liquid adhering to the writing paper 10 will be described with reference to FIG. The writing paper 10 becomes a transparent state (including a semi-transparent state) due to the adhesion of the liquid, and becomes opaque when dried.
And a transparent sheet 10b that is always transparent (including a semitransparent state) are laminated to form a two-layer structure. When the liquid adheres to the colored layer 10a, the liquid becomes the colored layer 10a.
Permeates the inside of the colored layer 10a while being wet, and the portion of the colored layer 10a wetted by the liquid becomes transparent. Then, when the liquid reaches the transparent sheet 10b, the whole of the writing paper 10 in the paper thickness direction becomes transparent, and the portion to which the liquid does not adhere remains in the color of the opaque colored layer 10a, and the contrast forms an image. It was done. The colored layer 1 was in a transparent state when the attached liquid evaporated.
0a returns to the original opaque state, and the image disappears.

As the liquid for forming an image, a colorless and transparent liquid such as water or an organic solvent (alcohols / esters) is used in order to prevent color components from remaining on the writing paper 10 after evaporation. To do. The time until the formed image is naturally erased depends on the type of liquid used, and according to specific experimental results, water is 5 minutes, propylene glycol is 1 hour, ethylene glycol is 3 hours, and diethylene glycol is 3 hours. Is 6 hours. Therefore, it is desirable to use ethylene glycol or diethylene glycol when displaying an image once formed for a long time, and it is preferable to use water when changing an image once formed one after another for a short time.

In such a structure, the brush paper 10 is moved in the direction of arrow a by driving the motor 12, and
Based on the image data input from the FD or ID card to the image data input device 15, a colorless transparent liquid is ejected from the inkjet head 13 to form an image on the writing paper 10.

When the portion of the writing paper 10 on which the image is formed moves between the platen glass 6 and the Fresnel lens 4, the driving of the motor 12 is stopped, and the light from the light source 2 is transmitted to the writing paper 10. Irradiate. Then, the light transmitted through the transparent portion of the writing paper 10 is projected onto the screen 9, and the image formed on the writing paper 10 is displayed on the screen 9.

The image displayed on the screen 9 becomes a white image on a black background because only the image portion becomes transparent when liquid is attached to the image portion to be formed. on the other hand,
When the liquid is attached to the non-image portion without attaching the liquid to the image portion, the non-image portion becomes transparent and becomes a black image on a white background, that is, a so-called positive image.

After the display of the image on the screen 9 is completed, the motor 12 is driven again to move the brush paper 10 in the direction of arrow a. At this time, the portion of the writing paper 10 on which the image is formed is heated by the heating roller 14 to forcibly dry the adhered liquid, the image is surely erased, and the next image on the writing paper 10 is erased. Writing can be performed well.

In reality, since the temperature inside the main body case 1 becomes high, it is expected that the time on which the image on the writing paper 10 disappears is shortened. In addition, the image is erased by the heat from the light source 2 while the brush paper 10 is being sent. Therefore, the heating roller 14 can be omitted. Further, as described above, since the inside of the main body case 1 has a high temperature, a fan 14a is provided in the vicinity of the light source 2 as shown in FIG. When it is desired to stop the image 14a and hold the image for a relatively long time, the fan 14a can be rotated to suppress the internal temperature rise.

Here, in this overhead projector, an image corresponding to the image data written in the FD or the ID card is formed by using the ink jet head 13 on the writing paper 1.
It is possible to display the image on the screen 9 by forming the image on the screen 9. Therefore, the display of image data created by a word processor or a personal computer on the screen 9 can be achieved at a lower cost than when a liquid crystal display panel is used.

Further, when the liquid is jetted by the ink jet head 13 to wet the entire surface of the writing paper 10, the entire writing paper 10 becomes transparent. Then, after making the entire writing paper 10 (or at least the range corresponding to the platen glass 6) transparent, that part is positioned on the platen glass 6 and an OHP sheet document is placed on the platen glass 6. By placing the image on the OHP sheet document, the image written on the OHP sheet document can be displayed on the screen 9.

Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those described in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted (the same applies hereinafter). In this embodiment, the platen glass 6 of the overhead projector described with reference to FIGS. 1 and 2 is provided slidably between a position that covers the top of the writing paper 10 and a position that opens it.

In such a structure, the platen glass 6 is placed.
As shown in FIG. 3, by sliding the upper part of the writing paper 10 to the open position, an image can be directly handwritten on the writing paper 10 with a felt pen impregnated with a liquid, and the handwritten image can be displayed. It can be displayed on the screen 9. Furthermore, when an image formed based on the image data input to the image data input device 15 from the FD or ID card is displayed on the screen 9 for presentation,
If necessary, additional images can be written and displayed on the screen 9.

Next, a third embodiment of the present invention will be described with reference to FIG. The basic structure of the overhead projector of this embodiment is the same as that of the overhead projector of the first embodiment, except that the loop-shaped writing paper 10 is used instead of the loop-shaped endless belt 17. That is the point. In the endless belt 17, the range from A to B along the loop direction of the endless belt 17 is the brush paper 17a as shown in FIG. 2, and the range from B to A is the transparent member 17b such as vinyl. The brush paper 17a and the transparent member 17b are joined together.

In such a structure, liquid is ejected from the ink jet head 13 while the brush paper 17a is moving at a position facing the ink jet head 13, thereby inputting from the FD or ID card to the image data input device 15. An image based on the created image data
7a, and the image can be displayed on the screen 9.

On the other hand, the transparent member 17b is replaced by the Fresnel lens 4
When the OHP sheet original is placed on the original table glass 6, the image written in the OHP sheet original can be displayed on the screen 9 by placing the OHP sheet original on the original table glass 6.

Next, a fourth embodiment of the present invention will be described with reference to FIG. The basic structure of the overhead projector of the present invention is the same as that of the overhead projector of the first embodiment, except that the transparent sheet 10b of the loop-shaped writing paper 10 is colored and colored according to the loop direction. , The range from A to B is red, and B
The range from to A is blue.

In such a configuration, the transparent sheet 10b of the writing paper 10 forms an image on the red portion, so that the image (image portion or the ground portion) displayed on the screen 9 becomes red, and the transparency of the writing paper 10 becomes transparent. When the sheet 10b forms an image on the blue portion, the image (image portion or ground portion) displayed on the screen 9 becomes blue. Therefore, the color of the image can be changed according to the content of the image, and a visually effective image can be displayed.

In this embodiment, the transparent sheet 1
Although the case where 0b is color-coded into two colors of red and blue has been described as an example, it may be color-coded into multiple colors including yellow, green and other colors, and further, a colorless portion may be included. Good.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In the main body case 1, a liquid application unit 18 that applies a liquid to the entire surface of the writing paper 10 with the movement of the writing paper 10 is provided. The liquid applying means 18 is
Liquid tank 18a for storing liquid, and the above-mentioned moving writing paper 1
It is formed by a coating roller 18b which comes into contact with 0 and coats this liquid on the brush paper 10.

Further, in the main body case 1, between the liquid applying means 18 and the Fresnel lens 4 along the moving direction of the writing paper 10, a thermal head 19 as an image forming means and a pressure roller 20 are provided. Is provided with the brush paper 10 sandwiched therebetween. Further, an FD or ID card in which image data of an image to be formed on the writing paper 10 is written is detachably attached to the overhead projector, and the image data written in the FD or ID card is read. An image data input device 21 having a function is connected. The image data input device 21 is connected to a head controller 22 which is a control means for controlling heat generation of the thermal head 19 based on image data input by reading from an FD or an ID card.

In such a structure, when the brush paper 10 is moved in the direction of the arrow a by driving the motor 12, the entire widthwise direction orthogonal to the moving direction of the brush paper 10 when passing the position of the liquid application means 18 is obtained. Is uniformly wetted by the liquid in the liquid tank 18a, and the entire surface of the writing paper 10 that has passed through the position of the liquid applying means 18 becomes transparent.

Then, when the brush paper 10 whose entire surface is transparent passes between the thermal head 19 and the pressure roller 20, it is based on the image data input to the image data input device 21 from the FD or ID card. Then, the thermal head 19 is caused to generate heat to heat the brush paper 10 with the thermal head 19 in accordance with a pattern corresponding to the image data and to evaporate the water in the heated portion, thereby forming an image on the brush paper 10.

When the portion of the writing paper 10 on which the image is formed moves between the platen glass 6 and the Fresnel lens 4, the driving of the motor 12 is stopped, and the light from the light source 2 is transmitted to the writing paper 10. Irradiate. Then, the light transmitted through the transparent portion of the writing paper 10 is projected onto the screen 9, and the image formed on the writing paper 10 is displayed on the screen 9.

Here, when the thermal head 19 is used to form an image on the brush paper 10, the image portion is dried to be opaque, and the image projected on the screen 9 is a positive image in which the non-image portion is transparent. be able to. Then, as compared with the case where the image is formed by the inkjet head 13 as described in the first to fourth embodiments, the positive image can be easily obtained. That is, in general, when comparing the ratios of the image portion and the non-image portion, the proportion of the non-image portion is large, and if a positive image is to be obtained by the inkjet head 13, the one with the larger proportion (non-image portion) is selected. It needs to be formed and is inefficient.

Therefore, in the method of forming an image by using the thermal head 19, a positive image can be obtained by forming the one with a smaller ratio (image portion), and therefore, a lower image can be obtained as compared with the case of using the ink jet head 13. Electricity,
A positive image can be obtained at high speed.

When an image is additionally recorded on the writing paper 10 by using a hot pen, the additionally recorded image also becomes a positive image,
When projected on the screen 9, the image becomes easy to see.

After the image is displayed on the screen 9, the motor 12 is driven to move the brush paper 10 to the arrow a.
Move in the direction. Then, when the portion of the writing paper 10 on which the image is formed passes the position of the liquid applying means 18, the image is erased, and the entire surface of the writing paper 10 becomes transparent again to prepare for writing the next image. It will be.

[0043]

According to the overhead projector of the invention described in claim 1, by inputting image data created by a word processor or a personal computer to the image data input device, an image corresponding to the image data is formed by the image forming means. It is possible to form the image on the writing paper and to display the formed image on the image display unit such as a screen. Therefore, the image data created by a word processor or a personal computer can be displayed on the screen or the like with respect to the writing paper and this writing paper. This can be achieved by an inexpensive structure in which an image forming means for forming an image is provided.

According to the overhead projector of the second aspect of the present invention, it is possible to form an image based on the image data created by a word processor or a personal computer on the portion of the brush paper in the endless belt and display the image on a screen or the like. Also, by moving the transparent member in the endless belt to a position where the light from the light source is irradiated and placing the OHP sheet document on this transparent member, the image written on the OHP sheet document is displayed on the screen or the like. It can also be used in a general way as an overhead projector.

According to the overhead projector of the third aspect of the present invention, by forming an image on a portion of the brush paper which is different in color of the transparent sheet, the color of the image projected on the screen or the like is changed according to the color of the transparent sheet. The image can be displayed in a visually effective state by changing the color according to the type of the image.

According to the overhead projector of the fourth aspect of the invention, since an image can be formed by applying the liquid to the entire surface of the writing paper with the liquid applying means and then drying the writing paper with the thermal head, a non-image portion can be formed. A black image on a transparent white background, that is, a so-called positive image can be formed at low power and high speed.

[Brief description of the drawings]

FIG. 1 is a front view schematically showing the overall structure of an overhead projector according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional front view showing the structure of brush paper.

FIG. 3 is a front view showing the outline of the overall structure of an overhead projector according to a second embodiment of the present invention.

FIG. 4 is a front view showing the outline of the overall structure of an overhead projector of a third embodiment of the present invention.

FIG. 5 is a front view showing the outline of the overall structure of an overhead projector of a fourth embodiment of the present invention.

FIG. 6 is a front view showing the outline of the overall structure of an overhead projector according to a fifth embodiment of the present invention.

FIG. 7 is a front view showing the outline of the entire structure of a general overhead projector of a conventional example.

[Explanation of symbols]

 2 light source 10 water writing paper 10a colored layer 10b transparent sheet 12 moving means 13 image forming means 15,21 image data input device 16,22 control means 17 endless belt 17a water writing paper 17b transparent member 18 liquid applying means 19 image forming means, thermal head

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takayoshi Kudo Inventor Takayoshi Kudo, Shibata-cho, Shibata-gun, Miyagi Prefecture, Nakameisei, Shinmei-do No. 3 Shinmeido, Tohoku Ricoh Co., Ltd. (72) Inventor, Katsuichi Chiba, Shibata-machi, Shibata, Miyagi Shinmeido 3 No. 1 Tohoku Ricoh Co., Ltd.

Claims (4)

[Claims] 1. A writing paper in which a colored layer and a transparent sheet, which become transparent when a colorless and transparent liquid is attached, are laminated, an image forming means for forming an image on the writing paper, and the writing paper. A light source for irradiating light, an image data input device for inputting image data of an image formed on the brush paper, and control means for controlling the image forming means based on the image data input to the image data input device. And an overhead projector. 2. An endless belt formed in a loop shape and having brushstrokes and transparent members alternately arranged along the loop direction is provided, and a moving means for moving the endless belt along the loop direction is provided. The overhead projector according to claim 1, wherein: 3. The brush paper is formed in a loop shape, the transparent sheet is color-coded into two or more colors along the loop direction, and a moving means for moving the brush paper along the loop direction is provided. The overhead projector according to claim 1. 4. The overhead projector according to claim 1, wherein liquid coating means for applying a liquid is provided on the entire surface of the writing paper, and a thermal head is provided as an image forming means.