Abstract:
An image recording apparatus comprises: an image recording apparatus comprising: a recording section disposed along a conveyable route of a transfer recording medium having a transfer recording layer whose transfer characteristics change when a first energy and a second energy different from the first energy are applied thereto, the recording section including a first energy applying means for applying the first energy to the transfer recording medium and a second energy applying means for applying the second energy thereto; a transfer means for transferring an image formed on the transfer recording medium in the recording section to a recording medium; and conveying means capable of conveying the transfer recording medium in the direction from the recording section to the transfer section and vice versa.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image recording apparatus applicable to printers, copying machines, electronic typewriters, facsimile equipment, and the like. 
     2. Related Background Art 
     In recent years, various kinds of information processing systems have been developed in conjunction with rapid progress made in the information industry. Recording methods and apparatus suitable for various information processing systems have also been developed and adopted. Among such recording methods, the thermal transfer recording method has been recently been used widely since the associated apparatus may be light in weight, compact and noise-free as well and excels in terms of operational features and maintenance capabilities. 
     The prior art heat transfer recording method is generally effected as follows: A heat transfer medium is used in which a thermal transfer ink with a coloring agent dispersed in a heat melting binder is applied to a sheet-like substrate, and this thermal transfer medium is superposed on a recording medium in such a manner that a thermal transfer ink layer will contact the recording medium. By supplying heat from the side of the thermal transfer medium&#39;s substrate by means of a thermal head to transfer the melted ink layer to the recording medium, a transferred ink image corresponding to the configuration of the heat supplied is formed on the recording medium. In accordance with this method, plain paper can be used as the recording medium. 
     However, conventional thermal transfer recording methods are not free from problems. In other words, with conventional thermal transfer recording methods, The transfer recording performance, i.e., the printing quality, is substantially affected by the smoothness of the surface of the recording medium. In the case of a recording medium with a low degree of smoothness, there usually results in a decline in the quality of images recorded. 
     In addition, if a multi-color image is to be obtained using a conventional thermal transfer recording apparatus, it is necessary to provide a plurality of thermal heads or provide either the transfer recording medium or the recording medium with complicated functions such as reverse feeding and stopping. Thus, there are problems in that the overall apparatus becomes large in size, complex, and that the recording speed declines. 
     Therefore, the present applicant invented image recording methods and transfer recording media which allow high-quality images to be recorded on a recording medium having a low degree of surface smoothness by overcoming the aforementioned problems of the prior art. In addition, the present applicant invented image recording methods and transfer recording media which allow multi-color images to be obtained without needing to have the recording medium perform complicated functions. The present applicant filed patent applications in Japan for these inventions as Japanese Patent Application Nos. 120080/1985 (filed on June 3, 1985), 120081/1985 (filed on June 3, 1985), 131411/1985 (filed on June 17, 1985), 134831/1985 (filed on June 20, 1985), 150597/1985 (filed on June 7, 1985), 199926/1985 (filed on Sept. 10, 1985), and 250884/1985 (filed on Nov. 11, 1985). Furthermore, on the basis of the priority rights afforded by these Japanese Applications, the present applicant filed an application in the United States (U.S. Ser. No. 869,689, filed on June 2, 1986) and a European application (Application No. 86107540.6, filed on June 3, 1986). 
     In addition, the present applicant further invented image recording apparatuses which are capable of effectively employing the aforementioned inventions, for which patent applications had been filed in Japan, the United States, and Europe. Thus, the present applicant filed patent applications in Japan for these inventions, and, on the basis of the priority rights afforded by these Japanese applications (priority date: Feb. 3, 1986), filed patent applications in the United States and Europe, the serial and application numbers thereof having not been given as yet. 
     The present invention which will be described below is a further development of the aforementioned inventions for which the present applicant filed the Japanese applications, the U.S. application, and the European application. The present invention can be applied, as necessary, to the image recording methods and transfer recording media described in the specifications of the aforementioned applications. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to provide an image recording apparatus which is capable of forming high-quality images on a recording medium with a low degree of surface smoothness (e.g., plain paper). 
     Another object of the present invention is to provide an image recording apparatus which is capable of effectively using a transfer recording medium without waste. 
     Still another object of the present invention is to provide an image recording apparatus which is capable of forming clear images. 
     A further object of the present invention is to provide an image recording apparatus which is capable of obtaining multi-color recorded images without the need to have a transfer recording medium or a recording medium perform complicated functions. 
     A still further object of the present invention is to provide an image recording apparatus which is capable of effecting in separate processes the formation of images on a transfer recording medium and the transfer of the images onto a recording medium. 
     To these ends, according to the present invention, there is provided an image recording apparatus comprising: a recording section disposed along a conveyable route of a transfer recording medium having a transfer recording layer whose transfer characteristics change when a first energy and a second energy different from the first energy are applied thereto, said recording section including a first energy applying means for applying the first energy applying means for applying the second energy thereto; a transfer means for transferring an image formed on the transfer recording medium in the recording section onto a recording medium; and conveying means capable of conveying the transfer recording medium in the direction from the recording section to the transfer section and vice versa. 
     These and other objects and features of the present invention will become apparent from the following detailed description of the invention when read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view schematically illustrating an image recording apparatus to which an embodiment of the present invention is applied; 
     FIG. 2 is an explanatory diagram schematically illustrating a conveying means; 
     FIG. 3 is a diagram explaining the arrangement of a transfer recording medium; 
     FIG. 4 is a diagram explaining the spectroscopic characteristics of reaction initiators contained in the transfer recording medium; 
     FIG. 5 is a diagram explaining the spectroscopic characteristics of a light source; 
     FIG. 6 is a timing chart for applying heat and light; 
     FIG. 7 is a block diagram illustrating control in accordance with the present embodiment; and 
     FIG. 8 is a flowchart thereof. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the accompanying drawings, description will be made of embodiments of an image recording apparatus in accordance with the present invention. As mentioned before, it goes without saying that the embodiments of the present invention can, as necessary, be applied to the image recording methods and transfer recording media described in the specifications of the aforementioned applications. 
     In an image recording apparatus in accordance with the present invention, a transferred image is formed by varying the physical properties governing the transfer characteristics. These physical properties are determined, as required, in accordance with the kinds of transfer recording media used. For instance, in the case of a transfer recording medium in which transfer is effected after rendering a transfer image in a thermally melted state, the physical properties are determined by the melting temperature, the softening temperature, or the glass transfer point. In the case of a transfer recording medium in which transfer is effected after rendering a transfer image in an adhesive state or in a state in which it is capable of permeating a recording medium, the physical properties are determined by the viscosity at an identical temperature. In addition, a plurality of kinds of energy used for forming a transfer image can also be determined as required. For instance, optoelectronic beams, heat, pressure, or the like may be used in a suitable combination. 
     An embodiment which will be described hereafter is an image recording apparatus for recording an image on a recording medium by using a transfer recording medium having a transfer recording layer whose physical properties governing transfer characteristics change on application of light energy and heat energy thereto, said apparatus comprising a conveying means for conveying the transfer recording medium; a recording section disposed along a conveying route of the transfer recording medium and having a heating means for applying heat energy thereto and an irradiating means for applying light energy thereto; a transfer section for transferring a transferred image formed in the recording section onto the recording medium; and a means for allowing the conveying means to reversely feed the transfer recording medium from the transfer section in the direction of the recording section. 
     In accordance with the above-described apparatus, if recording is carried out by setting the recording medium and the roll sheet-like transfer recording medium in the apparatus, the transfer recording medium is consecutively paid out by the conveying means, an image is formed on application of predetermined heat energy and light energy in the recording section, and the image is formed in the transfer section. 
     After the formation of the image, the transfer recording medium which is conveyed from the recording section to the transfer section in an unused state can be fed reversely until the rear end portion of the image reaches the position of the recording section after the image has been transferred onto the recording medium. Consequently, it is possible to effectively use the transfer recording medium without causing the same to produce an unused portion. 
     An embodiment of the present invention will now be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram illustrating an image recording apparatus, while FIG. 2 is an explanatory diagram of a conveying means of a transfer recording medium. In the drawings, a sheet-like transfer recording medium 1 is loaded as a supply roll 2 wound up in the form of a roll (detachably loaded around a loading shaft 2a of the main body of the apparatus). The transfer recording medium is conveyed from the supply roll 2 in the direction an arrow a by means of a conveying means 3. A latent image is formed on the transfer recording medium 1 by a recording section 4. The latent image is transferred onto a recording medium (e.g., plain paper or a plastic sheet for an OHP) 6 by a transfer section 5. After the transfer, the transfer recording medium 1 and the recording medium 6 are separated by a separation roller 7, and the transfer recording medium 1 is fed by a conveying roller 8 and taken up by a takeup roll 9. Subsequently, the recording medium 6 on which the image has been recorded is discharged onto a discharge tray 10. Incidentally, a cassette 12 accommodates the recording medium 6, which is fed to the transfer section by the rotation of a feed roller 13 on the side of the main body. In addition, a registration roller 14 conveys the recording medium 6 to the transfer section 5 in synchronization with the latent image formed on the transfer recording medium 1. Reference numeral 15 denotes a guide, while numeral 16 denotes a discharge roller. 
     A detailed description will now be made of the arrangement of the aforementioned respective parts. First, the transfer recording medium 1 is arranged such that an ink layer 1b, which has properties capable of forming a latent image in cases where both heat and light energy is applied thereto, is adhered to a sheet-like substrate 1a, as shown in FIG. 3. 
     As the transfer recording medium 1, those that are disclosed in the aforementioned specifications may be applied, but an example thereof will be given below. As shown in FIG. 3, the transfer recording layer 1b is constituted by microcapsule-like image-forming elements formed by the following method using the components shown Tables 1 and 2 as cores 1c,1d. In other words, 10 g of components shown in Tables 1 and 2 are mixed with 20 wt. % of methylene chloride, and this mixture is then mixed with 200 ml of water in which 1 g of gelatine and a cationic or nonionic surface active agent having an HLB value of at least 10 or above are dissolved. This mixture is agitated by a homo-mixer held at a temperature of 60° C. at a speed of 8000-10,000 r.p.m. to emulsify the same, thereby obtaining oily droplets having an average particle diameter of 26 μm. Furthermore, the mixture is further agitated for 30 minutes at 60° C., and the average particle diameter is reduced to approximately 10 μm by removing methylene chloride. 20 ml of water in which 1 g of gum arabic is dissolved is added to the same Subsequently, NH 4  OH (ammonium) is added to the mixture while cooling it gradually to set the pH to 11 or above, and a microcapsule slurry is thereby obtained. The walls of the microcapsules are hardened by gradually adding 1.0 ml of a 20% aqueous solution of glutaraldehyde to the same. Subsequently, the microcapsule slurry is separated into a solid and a liquid using a Nutsche funnel, and the solid is then dried by a vacuum cleaner for 10 hours at 35° C., thereby obtaining microcapsule-like image-forming elements. These image-forming elements are microcapsules in which the components 1c, 1d of Tables 1 and 2 are respectively covered with shells 1e, and are formed into a particle size of 7-15μm and an average particle size of 10 μm. 
     The image-forming elements thus formed are adhered on the substrate la constituted by a 6 μm-thick polyethylene terephthalate film, using an adhesive material 1f obtained by adding several droplets of a surface active agent to a 5% aqueous solution of PVA per 100 cc, thereby forming the transfer recording layer 1b. Thus the transfer recording medium 1 is arranged. 
     
                       TABLE 1______________________________________Item       Component            wt. %______________________________________Polymerizable prepolymer       ##STR1##            70Reaction   Irgacure-907         11initiator  (mfd. by Ciba-Geigy Corp.)Binder     PMMA2041             17Colorant   Diazine Red K      (mfd. By Mitsubishi Chemical                           2      industries, Ltd.)______________________________________ 
    
     The reaction initiator shown in Table 1 above starts reaction by absorbing light in the range shown in Curve A in the spectroscopic characteristics of FIG. 4 and assumes a color of red at the time of image formation. Meanwhile, the reaction initiator shown in Table 2 starts reaction by 
     
                       TABLE 2______________________________________Item       Component            wt. %______________________________________Polymerizable prepolymer       ##STR2##            75Reaction   2-chlorothioxanthone/ethyl-                           1.5/3initiator  Pdimethyl-amino-benzoateBinder     PMMA2041             18.5Colorant   Diazine Blue K      (mfd. by Mitsubishi Chemical                           2      Industries, Ltd.)______________________________________ absorbing light in the range shown by Curve B in the spectroscopic characteristics of FIG. 4 and assumes a color of blue at the time of image formation. 
    
     Description will now be made of the conveying means 3 for conveying the transfer recording medium 1. As shown in FIG. 2, a gear 3b of a stepping motor 3a which is driven in response to signals from a control section (a microcomputer 20 shown in FIG. 7) is engaged with a gear 3c. In addition, a pulley 3d is secured to the gear 3c by means of a shaft 3q, and a pulley 3f is connected to the pulley 3d via a one-way clutch 3e. 
     Furthermore, three pulleys 3h, 3i, and 3j are installed in such a manner as to rotate in the same direction as the rotational direction of the pulley 3f via a belt 3g. The pulley 3h is connected to a transfer roller 5a of the transfer section 5. The pulley 3i is connected to the conveying roller 8, while the pulley 3j is connected to the takeup roll 9. Thus, the arrangement is such that rotational forces are transmitted in the same direction as that of the rotation of the respective pulleys 3h, 3i, and 3j. 
     A pulley 3m is connected to the pulley 3d, connected to the gear 3c, by means of a belt 3k and a one-way clutch 3l, and is arranged such that a rotational driving force is transmitted in the same direction as the rotational direction of the pulley 3d. The pulley 3m is connected to the supply roll 2 of the transfer recording medium 1, and the arrangement is such that the supply roll 2 rotates in the same direction as the rotational direction of the pulley 3m. 
     When the gear 3c rotates in the direction of the arrow b, the one-way clutch 3e provided to the pulley 3f assumes a locked state and transmits a rotational force to the pulley 3f, but, when the gear 3c rotates in the direction of -b wherein (the minus sign indicates a reverse direction) it slips and does not transmit the rotational force to the pulley 3f. On the other hand, the one-way clutch 3l is arranged such that when the gear 3c rotates in the direction of the arrow b, it slips and does not transmit a rotational force to the pulley 3m, and when the gear 3c rotates in the direction of -b, it assumes a locked state and transmits the rotational force to the pulley 3m. 
     A braking member 3n urged by a spring 3o is provided to the shaft of the supply roll 2 and is so arranged that a predetermined braking force is imparted to the rotation of the supply roll 2. Thus a predetermined back tension is applied to the conveyance of the transfer recording medium 1. 
     Next, description will be made of the recording section 4, which is comprised of a heating means and an irradiating means. 
     As for the heating means, for instance, an array of 8-dot/mm, A-4 size (209 mm×297 mm) heating elements 4f of the line type each having a width of 0.2 mm and adapted to generate heat in response to video signals (issued from the microcomputer 20 shown in FIG. 7) are arranged on the surface of a recording head 4a. The arrangement is such that the substrate 1a side of the transfer recording medium 1 conveyed by the conveying means 3 is held in pressure contact with the array of heating elements 4f by means of back tension during the aforementioned conveyance at a predetermined angle by means of guide rollers 11a, 11b. 
     Meanwhile, two 20-Watt fluorescent tubes 4b, 4c, i.e., an irradiating means having the spectroscopic characteristics as shown in FIG. 5 are disposed at positions opposing the recording head 4a such as to be about 25 mm apart from the transfer recording medium 1. Furthermore, slit plates 4d, 4e are arranged in such a manner that an about 0.5 mm clearance exists between these slit plates 4d, 4e and the transfer recording medium 1 is maintained, while the width of their opening becomes 1.2 mm. 
     Incidentally, in this embodiment, as the fluorescent tube 4b having the spectroscopic characteristics shown by Curve A in FIG. 5, a 20-Watt health-ray fluorescent tube FL20SE made by Toshiba Corporation is used, while as the other fluorescent tube 4c having the spectroscopic characteristics shown Curve B, a 20-Watt copy-use fluorescent tube FL20BA-37 made by Toshiba Corporation is used. 
     Description will now be made of the transfer section 5. The transfer section 5 is disposed on the downstream side of the conveying direction of the transfer recording medium 1 during recording relative to the recording section 4, and is comprised of a transfer roller 5a rotating in the direction of an arrow d and a pinch roller 5b held in pressure contact with the transfer roller 5a, as shown in FIG. 1. 
     The transfer roller 5a is constituted by an aluminum roller with its surface coated with 1 mm-thick silicone rubber having a hardness of 70 degrees. The transfer roller 5a is so arranged that the temperature of its surface will be maintained in the range of 90°-100° by a 800-Watt halogen heater 5c incorporated therein. (In practice, the surface temperature of the roller 5a is detected by a temperature sensor 24 and is controlled by a CPU 20 shown in FIG. 7 in such a manner that the surface temperature will be held at the predetermined temperature.) 
     The pinch roller 5b is constituted by an aluminum roller with its surface coated with 1 mm-thick silicone rubber having a hardness of 70 degrees, and its pressing force relative to the transfer roller 5a is set to 12-15 kgf/cm 2 . 
     Referring next to a block diagram of a control system shown in FIG. 7, description will be made of control of the image recording apparatus having the above-described arrangement. 
     The control of the apparatus in accordance with this embodiment is effected by the microcomputer 20. This microcomputer is mainly comprised of a microprocessor 21, a memory 22, and an interface 23. A stepping motor 3a, i.e., a source for driving the conveying means, is driven as drive signals for executing the conveyance of the transfer recording medium 1, which will be described below, are transmitted from the interface 23 to a motor drive circuit 28. Similarly, a signals for lighting the fluorescent tubes 4b, 4c, i.e., the irradiating means, at a timing shown in FIG. 6 are also transmitted from the interface 23 to a fluorescent tube drive circuit 27, and signals for heating the thermal head 4a in correspondence with video signals are sent to a thermal head driven circuit 28. In addition, the interface 23 outputs signals for turning ON and OFF the heater 5c in the transfer roller 5a, detects the surface temperature of the roller 5a by the thermistor-type temperature sensor 24 as analog signals, and inputs the same as digital signals via an A/D converter 26. 
     In addition, in the memory 22 are stored the amount of rotation (set amount of rotation (1)) of the stepping motor 3a required in conveying a sheet of the transfer recording medium 1 of a given size (e.g., A-4 size, or B-5 size) in the forward direction in the direction from the recording section 4 to the transfer section 5 (i.e., in the recording direction) at the time when recording is effected on the recording medium, as well as an amount of rotation (set amount of rotation (2)) at the time when the transfer recording medium 1 is fed in the reverse direction, i.e., from the transfer section 5 to the recording section 4 (i.e., in the non-recording direction). Thus the rotation of the motor 3a is controlled with reference to the set values, as shown in a flowchart of control of conveyance (FIG. 8), which will be described later. 
     Incidentally, set values for each given size may be stored in a time table. 
     Description will now be made of operation in cases where recording is effected using the recording apparatus having the above-described arrangement. 
     As shown in FIG. 2, if the gear 3c is rotated in the direction of the arrow b by driving the stepping motor 3a, the one-way clutch 3e assumes a locked state, which in turn causes the pulley 3f to rotate, so that the belt 3g rotates in the direction of the arrow c. Consequently, the pulleys 3h, 3i, and 3j respectively rotate clockwise, so that the transfer roller 5a, the conveying roller 8, and the takeup roll 9 rotate clockwise. Consequently, the transfer recording medium 1 is consecutively fed in the direction of the arrow a while back tension is applied thereto from the supply roll 2. Also, front tension is imparted to the transfer recording medium 1 through slippage of a slip clutch 3p, thereby allowing the same to be taken up by the takeup roller 9. 
     Incidentally since the one-way clutch 3l slips at that time, a driving force is not transmitted to the supply roll 2. 
     Light and heat are imparted to the transfer recording layer 1b of the transfer recording medium 1 in the recording section 4 in correspondence with video signals (issued from the microcomputer 20 shown in FIG. 7), and a latent image is formed. In other words, the transfer recording layer 1b has a characteristic that, if heat and light of a predetermined wavelength are applied to the transfer recording layer 1b, its softening temperature rises, so that an image fails to be transferred onto the recording medium 6 by the transfer section 5. 
     Therefore, as shown of the timing chart in FIG. 6, at the time of red color recording, heating elements corresponding to video signals representing red are not energized, and portions corresponding to video signals representing white (the recording medium 6 is assumed to be white) are energized for 25 m.sec. Those portions are uniformly irradiated with the light of the fluorescent tube 4b with a time lag of 5 m.sec. At this juncture, the irradiation time is set to 45 m.sec. 
     Then, at the time of effecting blue color recording, after a pulse of 50 m.sec. upon completion of the irradiation, i.e., in 100 m.sec. from the time of starting energization, heating elements corresponding to video signals representing blue are not energized, and those portions corresponding to video signals representing white are energized for 25 m.sec. and are irradiated uniformly with the light of the fluorescent tube 4c with a time lag of 5 m.sec. The irradiation time at this juncture is 45 m.sec. as in the above. 
     A negative latent image is formed by controlling the recording head 4a in correspondence with the video signals representing red, blue and white in the procedure as described above. The transfer recording medium 1 is conveyed by the rotation of the conveying roller 8 and the pinch roller 8a driven by the same in synchronization with a repeated cycle of 200 m.sec./ line. When the transfer recording layer 1b on which the latent image has been formed is held in pressure contact with the recording medium 6 and heated in the transfer section 5, the transferred image of the two colors of red and blue are transferred onto the recording medium 6. Subsequently, the transfer recording medium 1 and the recording medium 6 are separated by a release roller 7, and the recording medium 6 for which the transfer of the image has been completed is discharged onto the discharge tray 10. 
     In the above-described transfer recording process, transfer recording is completed at the point of time when the rear end of the latent image is released from the recording medium 6 by the release roller 7. However, the portion of the transfer recording medium 1 between the recording section 4 to the release roller 7 remains unused (i.e., a latent image is not formed). 
     In this embodiment, when the rear end of the latent image formed on the transfer recording medium 1 is conveyed to the position of the release roller 7 and is released from the recording medium 6, the stepping motor 3a shown in FIG. 2 rotates in the opposite direction of the aforementioned case by means of a signal issued from the control section (i.e , the microcomputer 20 shown in FIG. 7), so that the gear 3c rotates in the direction of the arrow -b. 
     At that time, since the one-way clutch 3e slips a driving force is not transmitted to the pulley 3f. However, the other one-way clutch 3l assumes a locked state, so that the pulley 3m rotates counterclockwise, and this rotational force is transmitted to the supply roll 2. 
     Accordingly, the supply roll 2 rotates in the direction of the arrow -a to wind back the transfer recording medium 1, and when the position of the rear end of the latent image is wound back to the position of the recording head 4a from the position of the release roller 7, the motor 3a stops, thereby completing the entire transfer recording process. 
     A more detailed description will be made of the above-described control with reference to the flowchart shown in FIG. 8. 
     First, on starting of recording, the stepping motor 3a is rotated in the forward direction in such a manner that the transfer recording medium 1 will be conveyed in the direction of a (this direction shall be called the forward direction or recording direction) shown in FIG. 1, and the cumulative amount of rotation is counted up (Step S1). Then, while recording is in progress, discrimination is made as to whether or not the aforementioned amount of rotation has reached a set amount of rotation (1) (Step S2). If it has not reached the set amount of rotation (1), the motor 3a is rotated continuously to conveying the transfer recording medium 1. If the amount of rotation has reached the set amount of rotation (1), discrimination is made as to whether or not recording at this time coincides with the final value of the number of sheets to be recorded which has been designated by the operator (Step S3). At that juncture, if it is not the final recording, the cumulative amount of rotation is reset, and the operation returns to Step S1 (Step S4). In addition, in the case of the final recording, the rotational direction of the motor 3a is changed over to the reverse direction so as to convey the transfer recording medium 1 in the direction of b (this direction shall be called the reverse direction or nonrecording direction) shown in FIG. 1 (Step S5). Then, the amount of rotation of the motor 3a after conveying the transfer recording medium 1 in the reverse direction is counted up (Step S6). Then, discrimination is made as to whether or not the amount of rotation of the motor 3 has reached the set amount of rotation (2) (Step S7). If the amount of rotation has not reached the set amount of rotation (2), the motor 3a is rotated continuously in the reverse direction to continue the winding up of the transfer recording medium 1. On the other hand, if the amount of rotation has reached the set amount of rotation (2), the rotational direction of the motor 3a is changed over to the forward direction and the motor 3a is then stopped (Step S8). In addition, the count of the amount of rotation of the motor 3a required in conveying the transfer recording medium 1 in the reverse direction is reset (Step S9). 
     It should be noted that the set amount of rotation (1) referred to herein means the (cumulative) amount of rotation of the motor 3a required in conveyance until the rear end of the latent image-forming portion of the transfer recording medium 1 is completely released from the recording medium 6 (i.e., until it passes through the release roller 7). This set amount of rotation (1) varies in accordance with the various sizes of the recording medium 6, and may be stored in a time table or the like, as mentioned earlier. In addition, the set amount of rotation (2) means the (cumulative) amount of rotation of the motor 3a required in conveying the rear end of the trace of the latent image-forming portion remaining on the transfer recording medium 1 (the trace in which the transfer recording layer 1b has been transferred onto the recording medium 6 by the transfer section 5) from the point of changeover of the rotation of the motor 3a up to slightly before or immediately before the recording head 4a. Incidentally, the set amount of rotation (2) may be determined, as necessary. 
     Hence, in accordance with this embodiment, if the next recording is started, it is possible to form a latent image without leaving an unused portion in the transfer recording medium 1. 
     As described above, by controlling the forward and reverse conveyance of the transfer recording medium 1, it becomes possible to effectively utilize the transfer recording medium 1 without waste by reducing the unused area on the transfer recording medium 1. 
     Incidentally, although in the present embodiment an example has been shown in which the transfer recording medium is fed in the reverse direction immediately after recording of the final image, the present invention should not be restricted to the aforementioned embodiment. For instance, an arrangement may be provided such that the apparatus is stopped as it is after the recording of the final image, and the transfer recording medium may be fed in the reverse direction prior to starting the next new image recording. 
     In reverse feeding the transfer recording medium 1, since the number of lines from the release roller 7 to the recording head 4a is fixed, it is readily possible to control the amount of rotation of the stepping motor 3a. 
     It should be noted that although, in the above-described embodiment, description has been given in the case of two-color recording, it is also possible to effect transfer recording of a single or full-color image by selecting, as required, the kinds of a colorant and a reaction initiator constituting image-forming elements and by selecting a light source of a wavelength necessary for the reaction of the reaction initiator. 
     In addition, although the arrangement is such that, in the recording section 4, light of a predetermined wavelength is applied uniformly from the transfer recording layer lb side of the transfer recording medium 1, and heat in correspondence with video information is applied from the substrate 1a side, it is also possible to provide an arrangement as another embodiment in which heat is applied uniformly, and light of a predetermined wavelength is applied in correspondence with video information. Furthermore, an arrangement may be provided such that light is applied from the substrate la side by forming the substrate la with a light-transmissive material, and heat is applied from the transfer recording layer 1b side. 
     Moreover, although in the above-described embodiment irradiation and heating are carried out by placing the substrate 1 in between, it is also possible to effect image formation by conducting both irradiation and heating from one side of the substrate 1a. 
     As for the material of the substrate 1a, polyamide, polyamide-imide, etc. may also be used in addition to the aforementioned polyethylene terephthalate. 
     As for the irradiating means, in addition to the aforementioned method of using the fluorescent tubes 4b, 4c, it is also possible to employ, for instance, a method in which an LED array is used, or one which a xenon lamp and a filter which has matching light absorption characteristics in terms of its material. 
     As for the heating means, it is also possible to employ a method in which heating is carried out selectively using a YAG laser and a polygon mirror, in addition to the method of using the aforementioned recording head. 
     Furthermore, as for the recording medium, for instance, a plastic sheet and the like for an overhead projector (OHP) may be used in addition to paper. 
     Although, in the above-described embodiment, light energy and heat energy are applied simultaneously to the transfer recording layer 1b, an arrangement may be provided such that light energy and heat energy are applied separately, as both energizes are applied ultimately. 
     the above-described embodiment, transfer recording is effected by forming a transferred image based on a difference in the transfer recording characteristics with respect to the recording medium due to the change in the softening temperature of the image-forming elements of a high molecular material containing a colorant by the use of light energy and heat energy. However, it goes without saying that an arrangement may be provided such that a transferred image is transfer-recorded onto the recording medium by forming a transferred image based on a difference in the sublimation characteristics in respect of the recording medium, or such a transferred image that will change the coloring characteristics of the recording medium. It is also possible to adopt an arrangement in which such a recording medium that will directly undergo coloration by means of light and heat energy, instead of forming a transferred image, is used in the manner of the transfer recording medium. 
     As described above, since the present embodiment is capable of imparting both light and heat to the transfer recording medium in the recording section, it is possible to use an opto- and thermo-sensitive transfer recording medium and form an image thereon, thereby forming a single- or full-color recording. In addition, since a transferred image formed in the recording section is transferred separately in the transfer section, it becomes possible to effect transfer positively. 
     Furthermore, since the conveying means of the transfer recording meidum is capable of reversely feeding the transfer recording medium, it is possible to wind back the transfer recording medium which has been conveyed in an unused state from the recording section to the transfer section after completion of the image formation. Consequently, it is possible to effectively utilize the transfer recording medium, i.e., an expendable, without causing the same to produce an unused portion. 
     As described above, the present invention provides an image recording apparatus which is capable of using the transfer recording medium effectively.