JPH0557980A - Image display device - Google Patents

Abstract

(57) [Abstract] [Purpose] To use a thermoreversible recording material in an image display device to achieve both a large screen and high definition, and to control the number of repetitions of recording and erasing of the thermoreversible recording material. The first purpose is to provide an image display device that detects the life and displays the replacement time of the thermoreversible recording material, and prevents deterioration of display performance due to repeated recording and erasing at the same location. This is the second purpose. [Structure] A thermoreversible display sheet is used for display of an image forming apparatus, and the thermoreversible display sheet is recorded by a thermal head and can be erased by another thermal head. The CPU and the non-volatile RAM count the total number of times of writing on the thermoreversible display sheet, and the life of the thermoreversible display sheet can be determined by the total number of times of writing on the thermoreversible display sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device in an image forming apparatus such as a word processor or a facsimile for visualizing image data or character data.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device has been used for applications requiring portability as a display device of an image forming apparatus, and a CRT (cathode ray tube) has been used for applications requiring recognition. Further, as disclosed in Japanese Patent Laid-Open No. 57-212481, a thermoreversible recording material was used as a display device.

[0003]

However, it has been difficult to increase the screen size of liquid crystal display devices, and it has been difficult to increase the screen size and thickness of CRTs. Further, a display device using a thermoreversible recording material does not have a mechanism for detecting the life of the thermoreversible recording material, even though there is a limit to the number of times of repeating recording and erasing of the thermoreversible recording material. There was a drawback that the display gradually became difficult to read, and finally it became unreadable. In addition, if the position detection mark is provided to make the display position constant, it is recorded at the same place,
There is also a drawback that the life is shortened due to repeated erasing.

The present invention has been made in order to solve the above-mentioned problems, and by using a thermoreversible recording material in an image display device, it is possible to achieve both a large screen and a thin structure.
The first object is to provide an image display device that detects the life of the thermoreversible recording material by controlling the number of repetitions of recording and erasing, and displays the replacement time of the thermoreversible recording material. The second purpose is to prevent deterioration of display performance due to repeated recording and erasing.

[0005]

To achieve this object, an image display device of the present invention comprises a thermoreversible recording material for recording image information and selective heating for recording on the thermoreversible recording material. A recording means; an erasing means for erasing the recorded image information; and a conveying means for conveying the thermoreversible recording material, and a storage means for storing the number of times of recording and erasing performed on the thermoreversible recording material. And a display device for displaying the judgment result when the life of the thermoreversible recording material is judged based on the number of times stored in the storage means, and when the judgment means judges that the life has expired.

[0006]

The image display device of the present invention having the above structure is
Image information is recorded on the thermoreversible recording material by the selective heating recording means, is conveyed by the conveying means to display an image, and the unnecessary image is erased by the erasing means, and the number of recording and erasing is stored. When the number of times stored in the storage means and stored in the storage means exceeds a predetermined number, the determination means determines that the reversible recording material has reached the end of its life, and displays on the display means a message prompting replacement of the reversible recording material. do.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, the structure of the thermoreversible display sheet 11 will be described with reference to FIG. FIG. 2 is a cross-sectional view of the thermoreversible display sheet 11, which shows a transparent polyester film 2
0 has a recording layer 22 on it, and an overcoat layer 23 is provided to protect the recording layer 22. Recording layer 2
In No. 2, the organic low molecular weight substance 24 is dispersed in the resin.

Next, the cloudy state and transparent state of the thermoreversible display sheet 11 will be described with reference to FIG. In the state on the left side of FIG. 3, since the particles of the organic low molecular weight substance 24 in the thermoreversible display sheet 11 are composed of a relatively large single crystal, the light incident on the thermoreversible display sheet 11 receives the crystal interface. The light passes through a few times, the light passes through without being scattered, and it looks transparent as a whole. In the state on the right side of FIG. 3, since the particles of the organic low molecular weight substance 24 in the thermoreversible display sheet 11 are composed of polycrystals, the thermoreversible display sheet 11 is shown.
Light incident inside is refracted and scattered many times at the crystal interface, and appears as cloudy as a whole.

The thermoreversible characteristic of the thermoreversible display sheet 11 will be described with reference to FIG. First, when the thermoreversible display sheet 11 is in a cloudy state at room temperature, when it is heated, the transmittance starts to increase from the temperature A and reaches the maximum transparent state at the temperature B. And even if it is cooled to room temperature, the transparent state is maintained. This is because the organic low molecular weight substance 24 changes from a cloudy polycrystal to a semi-molten state in the process of increasing the temperature from A to B, and the crystal grows to a transparent single crystal when cooled to room temperature again. This is because. Next, when the transparent thermoreversible display sheet 11 is reheated to a temperature of C or higher, it becomes an intermediate state between the maximum transparent state and the maximum cloudy state. When it is cooled to room temperature, it returns to the original cloudy state. This is because the organic low molecular weight substance 24 is melted at a temperature of C or higher, and a polycrystal is deposited in the process of cooling to room temperature.

The temperature A is about 50 degrees, the temperature B is 56 to 68 degrees, and the temperature C is about 72 degrees. The recording means for recording on the thermoreversible display sheet 11 is the thermal head 4. By changing the energy given to one pixel determined by the resolution of the thermal head 4, the transparent state and the cloudy state can be set for each pixel. it can.

Further, by giving the thermoreversible display sheet 11 an intermediate temperature between the temperature A and the temperature B, the transmittance of the thermoreversible display sheet 11 can be freely set between the maximum transparent state and the maximum cloudy state. Can be adjusted. The thermoreversible display sheet 11
Since details of the above are described in Japanese Patent Laid-Open No. 63-39377, etc., the description thereof will be omitted here.

Next, the configuration of an embodiment in which the image display device of the present invention is applied to an image forming apparatus such as a word processor will be described with reference to FIGS.

FIG. 1 is a schematic sectional view of the image forming apparatus.
The image forming apparatus 2 is provided with a keyboard 30 for inputting data on the left side in the drawing, an LCD display device 20 for directly displaying the data from the keyboard 30 is provided on the right side of the keyboard 30, and the right side, that is, the central portion thereof. Is provided with an image display window 1. A thermoreversible display sheet 11 is stretched under the image display window 1 by the transport rollers 3 and 8 and the transport rollers 9 and 10, and the thermoreversible display sheet 11 is provided on the back side thereof.
A black plate 12 is provided for increasing the contrast of the image recorded on the disk. The thermoreversible display sheet 11 includes the transport rollers 3 and 8, the transport rollers 9 and 10, and the buffer unit 1.
3, the thermal head 4 for image recording and the writing platen 5 facing the same, and the thermal head 6 for image erasing and the erasing platen 7 facing the thermal head 4 are arranged in front of and behind the black plate 12. Are arranged, and each is arranged at a position sandwiching the thermoreversible display sheet 11. The buffer portion 13 includes a thermoreversible display sheet 11
Are stored, and the thermoreversible display sheet 11 is fed by the transport rollers 9 and 10 and pulled out by the transport rollers 3 and 8.

To the right of the conveying rollers 9 and 10, the printing paper 1
A chute 19 through which the paper 8 passes and conveyance rollers 16a, 16b and 17 for conveying the printing paper 18 are arranged.
A print head 14 that prints on the print paper 18 is disposed at a position facing the platen 15 between the a and 16 b and the transport roller 17.

FIG. 5 is a control block diagram of the image forming apparatus. The CPU 90 includes a ROM 91, a CG-ROM 92, and an R.
Read data from AM93 and non-volatile memory 94,
The keyboard 30 and the LCD display device 20 are controlled. The CPU 90 prints the print head 14 via the print head control circuit 98, the thermal heads 4 and 6 via the thermal head control circuits 100 and 102, and the display feed motor 103 via the display feed motor driver 104. The print feed motor 105 is controlled via the motor driver 106. The data input from the keyboard 30 is displayed on the LCD display device 20 via the CPU 90 and stored in the RAM 93.

Next, the operation of the image forming apparatus of this embodiment will be described.

The data input from the keyboard 30 is
It is recognized by the CPU 90, immediately displayed on the LCD display device 20, and stored in the RAM 93. RAM9
The data is temporarily stored in 3 is the thermoreversible display sheet 11
This is because the thermal head 4 for recording is recorded on a line-by-line basis. Therefore, if the thermal head 4 is recorded on the reversible display sheet 11 every time it is input from the keyboard 30, the life is shortened. The data stored in the RAM 93 is recorded on the thermoreversible display sheet 11 at the time when the data for one row is determined, is conveyed by the display feed motor 103, and is displayed on the image display window 1.

The detailed operation at this time will be described with reference to the display routine flowchart of FIG.

As an initial setting for displaying, first, RA
The head address of the data stored in M93, the amount of data to be displayed, and the condition of the display feed motor 103 are set (step S1). The conditions of the display feed motor 103 are speed, feed direction, and feed amount. The velocity is a velocity at which the amount of heat necessary for recording the thermoreversible display sheet 11 is given, and the feed direction is the thermoreversible display sheet 11 as shown in FIG. The direction in which the thermal head 4 is conveyed upward is used, and the feed amount is one line of the thermal head 4.

Next, the total writing number counter 120 (counter A in the figure) for counting the total writing number of the thermoreversible display sheet 11 provided in the non-volatile memory 94 is incremented by 1 and stored ( Step S2). Then, the data to be recorded on the thermoreversible display sheet 11 to the thermal head 4 is set to 1
The lines are transferred (step S3). Thermal head 4
Upon completion of data transfer to, the display feed motor 103 is turned on, and the display feed motor 103 is fed under the conditions set in step S1 (step S4). Then, in order to record the data on the thermoreversible display sheet 11, the strobe of the thermal head 4 is turned on,
Recording is performed (S5).

Further, 1 is added to the display line number counter 121 (counter B in the figure) provided in the non-volatile memory 94 for counting the number of display lines after the image information is completely erased and stored (S6). ). The display line number counter 121 is provided in order to know the area used by the thermoreversible display sheet 11, is used when erasing image information, and is cleared only when all image information is erased. The steps from S2 to S6 are repeated until the data is completed (S7). When the data is completed, the thermal head 4 is turned off (S8), the display feed motor 103 is turned off, and recording and display are terminated (S9).

The image information recorded on the thermoreversible display sheet 11 can be repeatedly confirmed by scrolling the thermoreversible display sheet 11 up and down by operating a key arranged on the keyboard 30. However, in that case,
Since it is necessary to always record the position of the trailing end of the recorded image information, the movement amount counter 122 (counter C in the figure) provided in the nonvolatile memory 94 has the line counted by the display line number counter 121. The amount of movement and the direction from the number are always stored.

Next, FIG. 7 shows a case where all the image information is erased.
This will be described with reference to the erase routine flowchart of FIG.

First, since the trailing edge of the recorded image information is conveyed to the erasing thermal head 6, the position of the trailing edge of the image information is confirmed. That is, the CPU 90 calculates the numerical values stored in the display line number counter 121 and the moving amount counter 122, and the rear end of the image information and the thermal head 4 are calculated.
The relative position with respect to is calculated (step S20). Next, the relative position between the trailing edge of the image information and the thermal head 6 is calculated (step S21), the display feed motor 103 is turned on (step S22), and the trailing edge of the image information reaches the erasing thermal head 6. The thermoreversible display sheet 11 is conveyed to (step S23). When the trailing edge of the image information reaches the erasing thermal head 6, the erasing counter 123 (counter D in the figure) for counting the number of erasing lines is reset and the erasing thermal head 6 is turned on (step S24).

Next, the feed direction of the display feed motor 103 is driven in the opposite direction to that in the display routine to start erasing the image information (step S25) and the erasing counter 1
1 is added to 23 and the total write number counter 120 (step S26). The display feed motor 103 is driven until the contents of the erasing counter 123 and the contents of the display line number counter 121 become equal (step S27), and when they become equal, the erasing thermal head 6 is turned off (step S28).

Then, the number of lines from the thermal head 4 to the thermal head 6 is subtracted from the number of lines stored in the display line number counter 121, and is substituted into the variable Y (step S29). Next, it is determined whether the variable Y is positive or negative (step S30), and if the variable Y is positive, the thermoreversible display sheet 11 is conveyed in the direction in which it is conveyed upward in FIG. 1 (step S30).
31), 1 is subtracted from the variable Y and the thermoreversible display sheet 11 is continuously conveyed until Y = 0 (step S3).
2). On the contrary, if the variable Y is negative, the thermoreversible display sheet 11 is conveyed in the downward direction in FIG. 1 (step S3).
3) Then, 1 is added to the variable Y and the thermoreversible display sheet 11 is continuously conveyed until Y = 0 (step S34). Y
When = 0, the thermoreversible display sheet 11 is conveyed by one line in the upward conveying direction in FIG. 1, and then the display feed motor 103 is stopped (step S3).
5).

Finally, it is judged whether or not the writing life of the thermoreversible display sheet 11 is over, and the present total writing data stored in the total writing number counter 120 of the non-volatile memory 94 (step S36). If not reached, the display line number counter 121 of the write line number counter since the last erasure is cleared (step S37). When the life is reached, the LCD display device 20
A message prompting replacement of the thermoreversible display sheet 11 is displayed (step S38).

The life of the thermoreversible display sheet 11 is determined by the number of writing and erasing operations per line, the sheet length, and the pixel length of the writing head in the sub-scanning direction. Assuming that the pixel length S of the thermal head in the sub-scanning direction is 1, and the number of write / erase per line N is N, the total number X of writes to the thermoreversible display sheet 11 is
It is represented by X = N * (L / S).

Therefore, the thermoreversible display sheet 1 is thus formed.
1 is controlled, the thermoreversible display sheet 1
The life of 1 can be determined by determining the total number of writings to the thermoreversible display sheet 11.

The present invention is not limited to the embodiments described in detail above, and various modifications can be made without departing from the spirit of the invention.

For example, although the present embodiment is described on the assumption that it is used in a word processor, if a communication input is provided, it can be easily applied to a facsimile and can be applied to other office equipment. ..

As the non-volatile memory, a normal RAM may be backed up by a battery.

Further, in the present embodiment, the image information is erased from the end, but it is clear that the same effect can be obtained even if the image information is erased from the end.

[0035]

As is apparent from the above description, since the image display device of the present invention is constructed so that the life of the image display device can be controlled by using the thermoreversible display sheet, it is possible to prevent the deterioration of the image quality. The user can be warned and the thermoreversible display sheet can be exchanged. Furthermore, recording and erasing can be repeated at the same location by making the next writing from the part following the region where writing and erasing have been performed once. It is also possible to prevent the display performance from deteriorating.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of the entire device of the present invention.

FIG. 2 is a cross-sectional view of a thermoreversible display sheet.

FIG. 3 is a diagram showing a transparent state and a cloudy state of a thermoreversible display sheet.

FIG. 4 is a diagram showing thermoreversible characteristics of a thermoreversible display sheet.

FIG. 5 is a block diagram of control means.

FIG. 6 is a display routine flowchart.

FIG. 7 is a part of an erase routine flowchart.

FIG. 8 is a part of an erase routine flowchart.

[Explanation of symbols]

 4 Thermal Head 6 Thermal Head 11 Thermoreversible Display Sheet 94 Nonvolatile Memory 103 Display Feed Motor

Claims (2)

[Claims] 1. A thermoreversible recording material for recording image information, a selective heating recording means for selectively heating the thermoreversible recording material for recording, and an erasing means for erasing the recorded image information. An image display device having a transporting means for transporting the thermoreversible recording material, and a storage means for storing the number of recordings and erasings performed on the thermoreversible recording material,
A determining unit that determines the life of the thermoreversible recording material based on the number of times stored in the storage unit; and a display device that displays the determination result when the determining unit determines that the lifetime is reached. Image display device. 2. The thermoreversible recording material according to claim 1, which is at least longer than the image display area, is formed into an endless shape or a winding roll shape, and all the image information stored in the thermoreversible recording material is recorded. When deleting, after deleting the image information,
An image display device comprising: a control unit that conveys the thermoreversible recording material and starts the next recording from a region following the erased region.