JP2736663B2 - Recording device using thermochromic film - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a recording device using a thermochromic film capable of writing and erasing an image on a film.

(Prior Art) The present inventors have proposed an overhead projector device which writes and forms an image previously read from a manuscript on a thermochromic film, and transmits and projects light on the thermochromic film. -167341).

The thermochromic film (hereinafter, also simply referred to as a film) has characteristics as shown in FIG. That is, when a film at room temperature a (transparent state) or d (opaque state) is heated to a first temperature b (63 to 67 ° C.), the film becomes optically transparent, and becomes transparent even when it is returned to room temperature. To maintain. Next, the film is heated at a second temperature c (around 72 ° C.).
When heated to opacity, it becomes opaque when d is returned to room temperature.

Therefore, if the first temperature (clearing temperature) is applied to the entire surface of the film on which the image has already been formed, the image is erased. Also, on the film that was erased and became transparent,
If a second temperature (white turbidity temperature) is selectively applied in accordance with a signal obtained by reading a document image, a new image is formed. As described above, by eliminating unnecessary images and forming a desired image, a large number of projection films can be formed from a limited length of film.

FIG. 5 shows an example of an overhead projector using such a thermochromic film, wherein 1 is a thermochromic film, 2 is an erasing roller and has a halogen heater 3 inside. Reference numeral 4 denotes a pressing belt, which presses the thermochromic film 1 against the erasing roller 2. Reference numeral 5 denotes a thermal head, which sequentially records according to the film transport of the platen roller 6. Reference numeral 7 denotes a stage glass, and 8 denotes a transport glass, on which a film on which an image is formed by the thermal head 5 is fed. 9 is a Fresnel lens, 10 is a projection lamp, 11 is a projection lens, and 12 is a mirror. Reference numeral 13 denotes a document moving table on which a document 14 of an image to be projected is placed and moved in the direction of the arrow. Reference numeral 15 denotes image reading means such as a CCD, which scans and reads the original surface in accordance with the movement of the original.

In the overhead projector configured as described above, the film 1 from which the image is erased by applying the clearing temperature by the erasing roller 2 is sequentially sent out. On the other hand, original images are sequentially read according to the movement of the original moving table 13,
The signal is sent to the thermal head 5, and the head selectively applies the clouding temperature to the erased film in accordance with the signal, and forms an image. When the film on which the image is formed reaches a predetermined position on the stage glass 7, the original moving table 13
Is moved outside the range through which the projection light passes. When the projection lamp 10 is turned on, a desired image is projected 4 on a screen (not shown) via the projection lens 11 and the mirror 12.

(Problems to be Solved by the Invention) Incidentally, since the erasing roller 2 applies a clearing temperature to the film 1, the material is preferably a metal having good thermal conductivity, for example, brass or aluminum.
At the same time, a layer having a high coefficient of friction, for example, a layer of rubber or the like is often formed on the surface because the film also serves to transport the film. Although there is a fixing roller of a copying machine having a configuration very similar to that of a copying machine, in this case, a material in which rubber having a thickness of 0.3 mm or more is adhered to the surface of aluminum is often used. However,
Unlike the fixing roller, which requires only a high temperature, in the case of the erasing roller, the temperature range of 63 to 67 ° C. must be strictly controlled. For that purpose, it is necessary to consider the surface temperature of the erasing roller and the heating time by the roller.

In FIG. 1, I represents a clearing temperature of 63 to 67 ° C. in an erasing roller having a 0.3 mm thick rubber layer formed on a metal surface.
Is a region in which is obtained. Here, since the heating time affects the film feeding speed, about 1 second is appropriate. In this case, the surface temperature of the erasing roller is set to about 75 to 79 ° C. due to the thermal conductivity of the rubber layer having a thickness of 0.3 mm. There is a need. However, when the film is curved as in the region I, the portion of the film that is in contact with the erasing roller is exposed to the opacity temperature for a long time during the stoppage of the feeding of the film. Formation becomes impossible.

On the other hand, II in FIG. 1 shows a region where the clearing temperature can be obtained in the erasing roller having no rubber layer on the metal surface.
At a temperature of around 70 ° C., even if the heating time is 1.0 second or longer, the temperature falls within the clearing temperature range. Therefore, even when the film is stopped, it can be reliably erased even in the case of continuous conveyance. However, in this case, since the friction coefficient of the roller surface is small, problems such as slippage occur.

Therefore, a first object of the present invention is to use a thermochromic film having a required coefficient of friction and having an erasing roller capable of securely erasing both heating for one second and heating during a stop. It is to provide a recording device.

Next, it is known that the thermochromic film promotes transparency and cloudiness not only by temperature but also by pressure. Since the clearing temperature is 63 to 67 ° C and its control range is narrow, by adding pressure action to this,
More reliable image erasure can be obtained.

Therefore, a second object of the present invention is to provide a recording apparatus using a thermochromic film provided with an erasing roller capable of securely erasing by using both temperature and pressure.

Since the thermochromic film is repeatedly used and erased and used many times, it is necessary to prevent scratches. In particular, when a strong printing pressure is applied, such as when printing on paper with a thermal head, the base surface of the film will be damaged, and the image will remain damaged even if the image is erased. become.

Therefore, a third object of the present invention is to provide a recording apparatus using a thermochromic film which does not cause print damage on the thermochromic film and can obtain a required contrast.

(Means for Solving the Problems) First, in order to achieve the first object, means for erasing an image of a thermochromic film has a thickness on a metal surface.
It consists of a roller with a rubber layer of 0.1 mm or less.

In order to achieve the second object, the means for erasing an image is provided with means for applying pressure to the thermochromic film while being heated to the erasing temperature.

Further, in order to achieve the third object, a thermal head for forming an image on a thermochromic film is arranged such that the print head pressure is determined by the coordinates of the print energy on the horizontal axis and the print head pressure on the vertical axis. This is configured to be used in an area smaller than a line where a print flaw is generated and larger than a line where a required contrast is obtained.

(Operation) When a rubber layer having a thickness of 0.1 mm is adhered to the surface of a metal as an image erasing roller, a region where a transparency temperature of 63 to 67 ° C. is obtained is a range of III in FIG. ,
If the surface temperature of the erasing roller is controlled to be about 70 ° C., the heating time of the film is 1 second, and even when the film is stopped, the film enters the substantially transparent temperature range.

Also, if a pressure applying means is added to the means for erasing an image, pressure is applied in a state where the image is heated to the erasing temperature, that is, in an activated state of the thermochromic film, so that the image can be erased very efficiently. it can.
As a result, the region where the clearing temperature can be obtained is the range IV in FIG. 1, and the surface temperature control range of the erasing roller is widened, so that reliable image erasing can be obtained.

Further, the printing pressure and printing energy of the thermal head are appropriately set, and as shown in FIG. 3, the printing pressure is set to be smaller than the print scratch generation line and larger than the required contrast line so that the damage to the film is prevented. Generation can be prevented.

(Example) Hereinafter, an Example is described in detail with reference to drawings. Second
The figure shows an embodiment of the present invention, and the parts having the same names as those in FIG. 5 are denoted by the same reference numerals. First, the erasing roller 2 is based on a metal 21, for example, aluminum,
A rubber layer 22 having a thickness of 0.1 mm is adhered to the surface. A halogen heater 3 is disposed inside, and the heater heats the erasing roller 2, and the thermochromic film 1 pressed and conveyed to the roller by the pressure belt 4 is heated to a transparency temperature. The film 1 is in contact with the roller for about one second when being continuously fed, and is in contact with the roller for a long time when the conveyance is stopped. Reference numeral 23 denotes a pressure roller, to which a pressure of, for example, 400 to 500 g / cm is applied while the film 1 is heated to the transparentizing temperature.
Reference numeral 24 denotes a neutralization brush arranged immediately before the thermal head 5 for removing dust adhering to the film 1. If there is dust, the film is hard and cannot be embedded in the film because it is hard, and cannot be moved between the thermal head and the film. The printing pressure and printing energy of the thermal head 5 are set within the range indicated by hatching in FIG.

Next, the operation of the present embodiment will be described. First, the erasing roller 2 has a thickness of 0.
Since the 1 mm rubber layer 22 is adhered, if the roller surface temperature at this time is set to around 70 ° C., the heating time is 1 second and the conveyance is stopped. As described above, the film 1 is heated in the range of the clearing temperature, and is not heated to the clouding temperature, so that the erasing operation can be performed reliably. Further, since pressure bonding by the pressure roller 23 is applied, the range of the clearing temperature is IV in FIG.
, The temperature control has a margin, and the erasing can be performed efficiently. Further, when the erasing roller 2 and the thermal head 5 are arranged close to each other, writing by the thermal head is performed before the temperature of the film heated to the erasing temperature falls, so that the printing energy of the thermal head can be reduced. Becomes possible. further,
In the thermal head 5, printing is performed with the printing pressure in the area indicated by hatching in FIG. 3, so that it is possible to prevent the occurrence of printing scratches on the film and to increase the number of times of use.

(Effects of the Invention) As described above, according to the present invention, the erasing operation of the thermochromic film can be reliably performed regardless of the length of the heating time, and the erasing operation can be performed by using the pressure in combination with the temperature. In addition, the thermochromic film can be easily printed, and the required contrast can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the surface conditions of the erasing roller, the heating time, and the clearing temperature region in the thermochromic film, FIG. 2 is a diagram showing the configuration of one embodiment of the present invention, and FIG. FIG. 4 shows the relationship between printing pressure and printing flaws.
FIG. 5 is a configuration diagram of an example of an overhead projector using a thermochromic film. 1 ... thermochromic film, 2 ... erase roller,
3 ... Halogen heater, 4 ... Crimping belt, 5 ... Thermal head, 6 ... Platen roller, 21 ... Metal, 22 ... 0.1 mm thick rubber layer, 23 ... Crimping roller.

Claims (3)

(57) [Claims] 1. Heating at a predetermined first temperature makes the film optically transparent, maintaining transparency even after returning to room temperature, and heating at a predetermined second temperature higher than the first temperature. Using a thermochromic film that becomes optically opaque and maintains opacity even when the temperature returns to room temperature, the previously formed image is erased by applying the first temperature, and the second temperature is selectively applied. A recording device for forming an image by applying the first temperature to the thermochromic film, wherein the means for erasing the image comprises a roller provided with a rubber layer having a thickness of 0.1 mm or less on a metal surface. A recording device using a thermochromic film. 2. The recording apparatus according to claim 1, wherein the means for applying the first temperature to the thermochromic film to erase the image applies pressure to the thermochromic film while heating to the erasing temperature. A recording device using a thermochromic film, characterized by comprising means. 3. Heating at a predetermined first temperature makes the film optically transparent, maintaining transparency even after returning to room temperature, and heating at a predetermined second temperature higher than the first temperature. Using a thermochromic film that becomes optically opaque and maintains opacity even when the temperature returns to room temperature, the previously formed image is erased by applying the first temperature, and the second temperature is selectively applied. A thermal head for forming an image by applying the second temperature to the thermochromic film, a print head at coordinates where the horizontal axis represents print energy and the vertical axis represents print head pressure. The thermochromic film is used in a region smaller than a line where a print flaw is generated on the thermochromic film and in a region larger than a line where a required contrast is obtained. Recording device using a thermochromic film.