Abstract:
A energy efficient thermal inkjet print head according to the present invention includes a plurality of the breathing nozzles configured around a main nozzle on a nozzle plate of an inkjet print head, the grouped resistors formed by the small resistors opposite the breathing nozzle building an insulation surrounding wall to enhance the spurting capability of a main heating resistor with forward kinetic energy and advantages such as ink and power saving, enhanced printing quality and efficiency and doubled speed of ink resupplying.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     (a) Field of the Invention  
         [0002]     The present invention relates to a energy efficient thermal inkjet print head comprising a plurality of grouped resistors around a main resistor. The aforesaid main resistor is an inkjet energy resource base, and the grouped resistors form the insulating walls enhancing the ink spurting capability of a main heating resistor by the forward kinetic energy.  
         [0003]     (b) Description of the Prior Art  
         [0004]     Laser printers and inkjet printers are the primary printers in the general market, and the printing technologies used in these two types of printers have their advantages and disadvantages. Presently, inkjet printing technology is the major printing technology used for color printing, and includes use of a thermal bubble inkjet print head that employs heating elements (such as: resistance heater elements) to momentarily direct high heat towards ink to produce bubbles, which are then sprayed out.  
         [0005]     Referring to  FIGS. 1 and 2 , which show a schematic view of a conventional ink cartridge  1  and a cutaway view of the ink cartridge  1  along the tangent  2 - 2  of  FIG. 1  respectively, wherein the ink cartridge  1  comprises a case  11 , interior of which forms an ink storage tank  12  that is used to store ink A and an inkjet print head  2  disposed on the ink cartridge  1  and interconnecting with the ink storage tank  12 . The inkjet print head  2  is used to control output of the ink A. A conventional inkjet print head chip  21  is disposed within the inkjet print head  2 , and includes a manifold  22 , which forms a channel between the inkjet print head  2  and the ink storage tank  12 . The inkjet print head  2  further comprises a nozzle plate  23 , and a plurality of ink chambers  24  are formed between the nozzle plate  23  and the chip  21 .  
         [0006]     The chip  21  comprises a plurality of heating resistors  211 , each of which are used to heat the ink A stored within a corresponding ink chamber  24  to produce bubbles. The nozzle plate  23  comprises a plurality of nozzles  231 , each of which corresponds to one of the heating resistors  211 . When a current passes through the heating resistors  211 , the ink A within the ink chambers  24  is heated, thereby producing bubbles, and the ink A is then able to be sprayed through the nozzles  231 .  
         [0007]     Because neither the satellite spurting holes are configured around a nozzle  231  of a conventional nozzle plate  23 , nor the grouped resistors are configured around the ink spurting power base of a heating resistor  211  (also known as a main resistor). Therefore, insulating surrounding walls are not built around the heating resistor  211  enhancing ink spurting capability of the main resistor and lacking the function of power assistance. Providing stable inkjet printing quality by speeding up the heating of the resistors with high voltage causes disadvantages such as great loss of power, scattered ink drops, delayed spurting or multi-dropped spurting. Since the speed of the conventional low-speed inkjets cannot be enhanced, and the inkjet nozzle  2  are not effective in saving power, the cost of printing is higher while the printing quality is lower.  
       SUMMARY OF THE INVENTION  
       [0008]     The primary object of the invention is to provide a energy efficient thermal inkjet print head consisted of a main heating resistor with curve-shaped top as an inkjet energy resource base of ink spurting. A plurality of grouped resistors forms the insulating surrounding walls around the main heating resistor by group capillarity enhancing the spurting capabilities of the main heating resistor by forward kinetic energy. The supporting power provided thereby avoids scattered ink drops, delayed spurting, multi-dropped spurting to prevent wasting of ink. The pressure difference of main energy resource and supporting power thereof accelerates the ink resupplying process and the printing process; furthermore, effectively saves ink and power while lowering the cost of printing and provides satisfying printing quality.  
         [0009]     To better understand the invention, detailed descriptions of a preferred embodiment shall be given with the accompanying drawings below. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  shows an elevational view of a conventional ink cartridge.  
         [0011]      FIG. 2  shows a cutaway view of a conventional ink cartridge along the tangent  2 - 2  of  FIG. 1 .  
         [0012]      FIG. 3  shows a partial sectional view of a energy efficient thermal inkjet print head according to the invention.  
         [0013]      FIG. 4-1  shows a diagram of a main heating resistor before forming air bubbles.  
         [0014]      FIG. 4-2  shows a diagram of a main heating resistor starting to form air bubbles.  
         [0015]      FIG. 4-3  shows a diagram of a main heating resistor when air bubbles are formed.  
         [0016]      FIG. 4-4  shows a diagram of a main heating resistor after air bubbles are formed.  
         [0017]      FIG. 5  shows an elevational view of a black and white inkjet print head of an ink cartridge according to the invention.  
         [0018]      FIG. 6  shows an elevational view of a color inkjet print head of an ink cartridge according to the invention.  
         [0019]      FIG. 7  shows another elevational view of a color inkjet print of an ink cartridge according to the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     As shown in  FIG. 3 , an inkjet print head  100  according to the invention comprising a main nozzle  201  on a nozzle plate  200  with an ink chamber  2001  inside. A main heating resistor  300  with curved top heating up the ink to form air bubbles is configured opposite the main nozzle  201 . When the air bubbles are formed, the ink is squeezed and spurted from the main nozzle  201  to print on papers. The invention is characterized in:  
         [0021]     A plurality of breathing nozzles  202  is configured around the main nozzle  201  of the nozzle plate  200 . A small resistor  301  is installed on each side of the breathing nozzle  202  to form the grouped resistors. The main heating resistor  300  with curved top is the ink spurting power base, and the small resistors  301  around form grouped resistors and build an insulating surrounding wall to increase spurting capabilities of the main heating resistor  300  with forward kinetic energy. The supporting power formed by the grouped resistors avoids disadvantage of ink wasting such as scattered ink drops and delayed spurting. The pressure difference formed by the main power of the main heating resistor  300  and the supporting power of the grouped resistors accelerates the ink refilling, and a physical change caused by the supporting power form air bubbles guiding and controlling the ink flow further while decreasing internal impedance. Based on the principle that the weight of the ink and the frequency of the ink spurting is an inverse ratio, the ink resupplying design that the power source leads the pressure speed solve the major disadvantage of a conventional inkjet printer.  
         [0022]     According to  FIG. 4-1 ,  FIG. 4-2 ,  FIG. 4-3  and  FIG. 4-4 , a main nozzle  201  and a breathing nozzle  202  thereof are facing downward.  FIG. 4-1  shows that the main nozzle  201  opposite a main heating resistor  300  and the breathing nozzle  202  opposite of a small resistor  301  have not formed air bubbles. Wherein, the surface tension of the base of the ink A remains balanced inside of an ink chamber  2001 .  
         [0023]     In  FIG. 4-2 , when the main heating resistor  300  and a plurality of small resistor  301  are being heated, a large air bubble T 0  of the main heating resistor  300  and a small air bubble T 1  of the small resistor  301  start to form and push the ink A inside of the ink chamber  2001  downward to the main nozzle  201  and the breathing nozzle  202 . The pressure from the main nozzle including a main power source P 0  and the supporting power source P 1  around. The total pressure thereof equals to the sum of P 0  and nP 1 , which is also the pressure of the main power source and the surrounding supporting power source.  
         [0024]     Referring to  FIG. 4-3 , when air bubbles T 0  and T 1  of the main heating resistor  300  and a plurality of small resistor  301  form, the ink A is spurted from the main nozzle  201  to the paper. The surface tension of the ink A remains at the breathing nozzle  201  to avoid various bad printing qualities such as small dotted ink spurting and delayed spurting to save the ink A and operating power.  
         [0025]     As shown in  FIG. 4-4 , after the main nozzle  201  finishes printing, the large air bubble T 0  and the small air bubble T 1  disappear, supporting power source P 4  returns to be below the heating resistor  300  from the breathing nozzle  202  assisting the pressure Pr and Pm to recover. The ink A is recovered to the state as shown in  FIG. 4-1  and being prepared for the next air bubble T 0  to form and spurt after the large air bubble disappear.  
         [0026]     Base on the theory resulted from the aforesaid physical experiment, not only the printing speed is increased more than three times, but more than 15% of the ink is saved.  
         [0027]     There is a plurality of surrounding breathing nozzle  202  around the main nozzle  201  of the nozzle plate  200  of a black and white printer as shown in  FIG. 5 . According to  FIG. 6  and  FIG. 7 , a plurality of surrounding breathing nozzle  202  around the main nozzle  201  of three colored nozzle plates  200  are configured in color printer.  
         [0028]     To emphasize novelty and practicability, the advantages of the invention are listed below: 
    1. Power saving—the power supplying time of the main heating resistor  300  is shortened, the air wall formed by the breathing nozzle  202  prevents wasting of the ink A and shortens the distance between the spurting hole and the paper to increase printing speed.     2. Printing quality enhancement-high-speed spurting preventing dissatisfying printing qualities such as scattered ink drops, delayed spurting, or multi-dropped spurting.     3. Enhanced printing speed.     4. Doubled ink resupplying speed.     5. Environmental friendly—the printer is designed that the environmental friendly materials can be used.    
 
         [0034]     In view of the above, the invention do not need to use the principles of hydrodynamics but principles of internal equilibrium for the inkjet nozzles to be more effective, power and cost saving, and improves the quality of printing.  
         [0035]     It is of course to be understood that the embodiment described herein is merely illustrative of the principles of the invention and that a wide variety of modifications thereto may be effected by persons skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims.