Patent Application
20110235286
(1) Field of the Invention
The present invention relates to display panel modules, and relates particularly to a display panel module which is intended for reduction in the number of circuit elements each incorporating a driving circuit for a display panel such as a liquid crystal panel (hereinafter, a driving circuit element), and which reduces costs for the display panel module.
(2) Description of the Related Art
In recent years, as a display apparatus to be used for a television set, a monitor, or the like, the market for flat panel display apparatuses such as a liquid crystal panel, a plasma display panel, and an organic EL panel has been growing. In addition, along with the market growth, prices of flat panel display apparatuses are declining at an accelerating pace. This results in a further growth of the market for flat panel display apparatuses, and makes it essential to reduce costs for the display panel module and peripheral devices in manufacturing the flat panel display apparatuses.
Here,
As a measure for reducing costs for the display panel module as described earlier, a very useful method is a method of reducing the number of the driving circuit elements 6 or the film packages 5. Accordingly, as shown in
However, according to a conventional configuration, along with decrease in the number of the film packages 5, it becomes more necessary to increase a vertical length Y of the wiring region 7 in order to secure the wiring region 7 in the display panel 9. This results in reduction in the number of panels to be taken from one glass substrate, and therefore does not reduce costs for a display panel module. In addition, when reducing, for the purpose of further reducing the costs, not only the number of the film packages 5 but also the number of the driving circuit elements 6, the vertical length Y of the wiring region 7 becomes longer. Here, the larger the display panel such as a television is, or the larger the number of pixels is, the more significant the problem becomes; thus, with the conventional configuration, it is difficult to reduce the number of driving circuit elements.
In addition, another problem in reducing the number of driving circuit elements 6 is that reduction in the number of driving circuit elements 6 results in increase in the number of outputs per one driving circuit element 6. In other words, this increases a circuit scale per one driving circuit element 6, thus increasing power consumption. As a result, the self-heating temperature of the driving circuit elements 6 increases to exceed a guarantee temperature of the driving circuit element 6 or causes deterioration in the characteristics of the driving circuit elements 6, thus deteriorating display quality.
An object of the present invention, conceived in view of the problems above, is to provide a display panel module or a display apparatus having a configuration which allows reduction in the number of driving circuit elements without decreasing the number of panels to be taken from a glass substrate, and allows enhancing heat dissipation characteristics of the driving circuit elements.
A display panel module according to an aspect of the present invention includes: a first flexible printed circuit board on which a circuit element for outputting pixel data is mounted; a display panel; and a second flexible printed circuit board having a plurality of first terminals connected to the first flexible printed circuit board and a plurality of second terminals each of which is provided for a corresponding one of the first terminals at a pitch larger than a pitch of the first terminals and is connected to the display panel and the corresponding one of the first terminals, the second flexible printed circuit board being for relaying the pixel data between the first flexible printed circuit board and the display panel.
In other words, a display panel module according to an aspect of the present invention connects an electrode of the film package on which the circuit element is mounted and an electrode of the display panel via at least one flexible printed circuit board, and secures, using the flexible printed circuit board, a wider connection region for connecting the flexible printed circuit board and the display panel than a connection region for connecting the film package and the flexible printed circuit board.
Here, in the display panel module according to an aspect of the present invention, it is preferable that the first flexible printed circuit board on which the circuit element is mounted be a film package. In addition, it is preferable that the second flexible printed circuit board be formed of the same material as the first flexible printed circuit board, specifically, the same film package as the film package used as the first flexible printed circuit board (however, a film package on which no chip is mounted).
The configuration as above produces an advantageous effect of reducing an area of the wiring region on the display panel, and increasing the number of display panels to be taken.
In the display panel module according to an aspect of the present invention, a plurality of circuit elements including the circuit element are mounted on the first flexible printed circuit board.
The configuration as above produces reducing package costs.
In the display panel module according to an aspect of the present invention, each of the plurality of circuit elements includes: a driving circuit element incorporating a driving circuit for the display panel; and one of a circuit element incorporating a controller circuit for controlling the driving circuit, and a circuit element incorporating a power circuit for generating a source voltage supplied to the driving circuit.
The configuration as above produces an advantageous effect of stabilizing operation characteristics of the driving circuit, and reducing members for configuring a display panel module, such as a wiring board.
In the display panel module according to an aspect of the present invention, the second terminals are arranged along a side of the second flexible printed circuit board, and a slit is provided on the side of the second flexible printed circuit board.
The configuration as above produces an advantageous effect of increasing reliability of connection between the second flexible printed circuit board and the display panel.
In the display panel module according to an aspect of the present invention, the slit is provided in a direction at 90 degrees with respect to the side of the second flexible printed circuit board.
The configuration as above produces an advantageous effect of improving efficiency in wiring between the second flexible printed circuit board and the display panel.
In the display panel module according to an aspect of the present invention, the side of the second flexible printed circuit board is separated into portions having an equal length by the slit.
The configuration as above facilitates a connection process for connecting the second flexible printed circuit board and the display panel, thus producing an advantageous effect of reducing man-hours.
In the display panel module according to an aspect of the present invention, the second flexible printed circuit board is formed into a trapezoidal shape having, as an upper base, a side along which the first terminals are arranged, and having, as a lower base, a side along which the second terminals are arranged.
The configuration as above suppresses size of the second flexible printed circuit board to a minimum, thus producing an advantageous effect of reducing costs for the second flexible printed circuit board.
The display panel module according to an aspect of the present invention further includes two second flexible printed circuit boards each being the second flexible printed circuit board, and the second terminals of the two second flexible printed circuit boards are connected to a same side of the display panel.
In the display panel module according to an aspect of the present invention, each of the two second flexible printed circuit boards is formed into a trapezoidal shape having, as an upper base, the side along which the first terminals are arranged, and having, as a lower base, the side along which the second terminals are arranged, and one of two sides connecting the upper and lower bases form an angle of 90 degrees with respect to each of the upper and lower bases.
The configuration as above increases the number of the second flexible printed circuit boards to be taken, thus producing an advantageous effect of cost reduction.
In the display panel module according to an aspect of the present invention, the first terminals are arranged in a staggered manner.
The configuration as above reduces the number of driving circuit elements, and thus suppresses, even when the number of outputs per driving circuit element is increased, increase in the area where the first terminals for connecting the film package and the second flexible printed circuit board are arranged, thus producing an advantageous effect of reducing package costs.
In the display panel module according to an aspect of the present invention, on the second flexible printed circuit board, a wire connected to a predetermined line of the first terminals arranged in the staggered manner and a wire connected to a line different from the predetermined line run in opposite directions.
The configuration as above allows reducing a wiring pitch of the film package to half a wiring pitch of the second flexible printed circuit board, thus producing an advantageous effect of reducing package costs by reducing the size of the film package.
In the display panel module according to an aspect of the present invention, the first terminals are connected to two different sides of the first flexible printed circuit board.
In the display panel module according to an aspect of the present invention, the first terminals are connected to three different sides of the first flexible printed circuit board.
The configuration as above allows increasing the number of the first terminals connecting the film package and the second flexible printed circuit board, without increasing a width of the film package, thus producing an advantageous effect of reducing package costs.
In the display panel module according to an aspect of the present invention, resistance values of a plurality of wires from the first terminals to the second terminals in the second flexible printed circuit board are uniform or approximately uniform.
The configuration as above suppresses variation such as a voltage drop caused by wiring resistance of an output signal from the driving circuit element, thus producing an advantageous effect of suppressing deterioration in display characteristics in the display panel module.
In the display panel module according to an aspect of the present invention, the wires on the second flexible printed circuit board have different lengths, and in the second flexible printed circuit board, a longer wire is wider than a shorter wire.
The configuration as above allows easily suppressing variation such as a voltage drop caused by wiring resistance of an output signal from the driving circuit element, thus producing an advantageous effect of suppressing a deterioration in display characteristics in the display panel module.
A display apparatus according to an aspect of the present invention includes: the display panel module as described above; and a material having high heat dissipation characteristics and provided in contact with the circuit element.
The configuration as above allows enhancing heat dissipation characteristics of the driving circuit element and increasing circuit size per driving circuit element, that is, increasing the number of outputs, thus producing an advantageous effect of reduction in the number of the driving circuit elements.
In the display apparatus according to an aspect of the present invention, the material having high heat dissipation characteristics is a chassis portion.
The configuration as above allows enhancing heat dissipation characteristics of the driving circuit element without adding another heat-dissipating member, and increasing circuit size per driving circuit element, that is, increasing the number of outputs, thus producing an advantageous effect of reducing the number of the driving circuit elements.
In the display apparatus according to an aspect of the present invention, the chassis portion includes a projection in a contact portion with the circuit element.
The configuration as above allows increasing contact between the chassis portion and the driving circuit element to enhance the heat dissipation characteristics of the driving circuit element, and increasing circuit size per driving circuit element, that is, increasing the number of outputs, thus producing an advantageous effect of reducing the number of the driving circuit elements.
As described above, a display panel module and a display apparatus according to an aspect of the present invention produces an advantageous effect of cost reduction in the display panel module by allowing reduction in the number of driving circuit elements in the display panel module without increasing the wiring region on the display panel, that is, without decreasing the number of panels to be taken from the same glass substrate.
In addition, the display panel module and the display apparatus allow the driving circuit element mounted on the film package in the display panel to be in contact with a material having high heat dissipation characteristics, which is, for example, the chassis portion in the display panel module. In other words, enhancement of the heat dissipation characteristics increases the number of outputs per driving circuit element, which allows reduction in the number of driving circuit elements in the display panel module, thus producing an advantageous effect of reducing costs for the display panel module.
The disclosure of Japanese Patent Application No. 2009-280275 filed on Dec. 10, 2009 including specification, drawings and claims is incorporated herein by reference in its entirety.
The disclosure of PCT application No. PCT/JP2010/006389 filed on Oct. 29, 2010, including specification, drawings and claims is incorporated herein by reference in its entirety.
These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings that illustrate a specific embodiment of the invention. In the Drawings:
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments below illustrate essentially preferable examples, and are not intended to limit the scopes of the present invention, the applications, or usages thereof.
The display panel module includes: a film package 5, a display panel 9, and a flexible printed circuit board 10. The display panel module has a configuration such that, when the number of driving circuit elements 6 mounted on the film package 5 is reduced to one, electrodes (terminals) of the film package 5 and electrodes (terminals) of the display panel 9 are connected via the flexible printed circuit board 10. Here, by increasing a width X102 of a connecting portion 102 between the flexible printed circuit board 10 and the display panel 9 to be longer than a width X101 of the connecting portion 101 between the film package 5 and the flexible printed circuit board 10, it is possible to further decrease a vertical length Y of the wiring region 7 on the display panel 9 as compared to the case of directly connecting the film package 5 to the display panel 9, thus realizing reduction in costs for the display panel module. The driving circuit element 6 is a semiconductor integrated circuit element for a display circuit, which includes a driving circuit for the display panel 9. The film package 5 includes: the driving circuit element 6, electrodes, and wires connecting the electrode and the driving circuit element 6, and a flexible wiring board on which the driving circuit element 6 is mounted. Note that the driving circuit element 6 has been described as an example of the circuit element for output of pixel data such as a scan signal or a pixel signal, but is not limited to this.
The display apparatus includes: a display panel module shown in
The flexible printed circuit board 10 includes: a plurality of electrodes (first terminals) 301 connected to the film package 5; a plurality of electrodes (second terminals) 302 arranged at a pitch larger than a pitch of the electrodes 301 and connected to the display panel; wires connecting the electrodes 301 and the electrodes 302; and a flexible wiring board on which the wires are formed. Here, the pitch is a space between a center of a width in an arrangement direction of a predetermined electrode and a center of a width in an arrangement direction of an electrode located next to the predetermined electrode.
The flexible printed circuit board 10 has a rectangular shape, and pixel data from the film package 5 is transmitted from the film package 5 to the display panel 9 via the flexible printed circuit board 10.
The electrodes 301 are arranged along a predetermined side of the flexible printed circuit board 10, and this predetermined side is part of the connecting portion 101. On the other hand, the electrodes 302 are arranged on another side opposite to the predetermined side of the flexible printed circuit board 10, and this other side is part of the connecting portion 102.
(Variation 1)
Next, a variation of the display panel module according to the present embodiment is described with reference to
As shown in
The electrodes 301 to be connected to the film package 5 are arranged in line on an upper base of the flexible printed circuit board 10 having a trapezoidal shape, and the electrodes 302 to be connected to the display panel 9 are arranged in line on a lower base of the flexible printed circuit board. Note that the lower base of the trapezoidal shape has a longer side than the side of the upper base.
(Variation 2)
Next, another variation of the display panel module according to the present embodiment is described with reference to
As shown in
Note that in the present variation, the controller circuit element 1 and the driving circuit element 6 are mounted on one film package 5. However, as long as the driving circuit element 6, and at least one of the controller circuit element 1 and the power supply circuit element are mounted, the circuit elements to be mounted on one film package 5 are not limited to these controller circuit element 1 and driving circuit element 6.
(Variation 3)
Next, another variation of the display panel module according to the present embodiment is described with reference to
As shown in
The electrodes 301 in the flexible printed circuit board 10 which are to be connected to the film package 5 are connected to two different sides of the film package 5, more specifically, to three different sides of the film package 5. These three sides include: a side of the film package 5, which is opposite to a predetermined side of the flexible printed circuit board 10; and other two sides of the film package 5 each of which is adjacent to the side opposite to the predetermined side.
(Variation 4)
Next, another variation of the display panel module according to the present embodiment is described with reference to
As shown in
The resistance value between the electrode 301 and the electrode 302 in each of the plurality of wires 201 in the flexible printed circuit board 10 is uniform or almost uniform. The plurality of wires 201 in the flexible printed circuit board 10 have different lengths, and in the flexible printed circuit board 10, a width of a longer wire 201 is greater than a width of a shorter wire 201.
The display panel module includes two separate flexible printed circuit boards 10a and 10b between the film package 5 and the display panel 9. In the display panel module according to the first embodiment as described earlier, when connecting the electrodes 302 of the flexible printed circuit board 10 and the electrodes of the display panel 9 by thermocompression bonding using anisotropically-conductive film (hereinafter, ACF) which is generally used as a method of bonding electronic components, it is necessary to design the pattern of each electrode such that the pattern includes a correction value, in consideration of distortion caused by difference in thermal expansion coefficient between the flexible printed circuit board 10 and the display panel 9. The longer the width X102 of the connecting portion 102 between the display panel 9 and the flexible printed circuit board 10 is, the more difficult it is to adjust this correction value. Thus, in the display panel module according to the present embodiment, the flexible printed circuit board 10 according to the first embodiment 1 is divided into two separate flexible printed circuit boards 10a and 10b as shown in
In addition, although not particularly shown, according to the second embodiment, as in the first embodiment described earlier, it is also possible to provide: a configuration which enhances heat dissipation characteristics by providing, in contact with the chassis portion 11 in the display panel module, the driving circuit element 6 mounted on the film package 5; a configuration in which a plurality of circuit elements are mounted on one film package 5; or a configuration which reduces variation in resistance value among the plurality of wires in the separate flexible printed circuit boards 10a and 10b.
(Variation 5)
Next, a variation of the display panel module according to the present embodiment is described with reference to
As shown in
The electrodes 301 to be connected to the film package 5 are arranged in line in the upper base of each of the separate flexible printed circuit boards 10a and 10b having a trapezoidal shape, and the electrodes 302 to be connected to the display panel 9 are arranged in line in the lower base of each of the separate flexible printed circuit boards 10a and 10b. One of the two sides connecting the upper and lower bases of the separate flexible printed circuit boards 10a and 10b forms an angle of 90 degrees with each of the upper and lower bases.
(Variation 6)
Next, another variation of the display panel module according to the present embodiment is described with reference to
As shown in
The display panel module has a configuration in which: a slit 103 that is a cut in one of the sides of the flexible printed circuit board 10 which is the side along which electrodes 302 are arranged, and in the flexible printed circuit board 10, the connecting portion 102 to the display panel 9 is divided by the slit 103. By dividing the connecting portion 102 between the flexible printed circuit board 10 and the display panel 9 into four parts having widths X102a, X102b, X102c, and X102d, as in the second embodiment described above, it is possible to reduce difficulty in adjusting the correction value that is to be considered for performing thermocompression bonding using ACF on the flexible printed circuit board 10 and the display panel 9, thus increasing reliability of the connection between the flexible printed circuit board 10 and the display panel 9.
In addition, although not particularly shown, according to the present embodiment, as in the first or the second embodiment described earlier, it is also possible to provide: a configuration which includes the flexible printed circuit board 10 having a trapezoidal shape; a configuration which enhances heat dissipation characteristics by providing, in contact with the chassis portion 11 in the display panel module, the driving circuit element 6 mounted on the film package 5; a configuration in which a plurality of circuit elements are mounted on one film package 5; a configuration in which the connecting portion 101 for connecting to the flexible printed circuit board 10 is provided along three sides of the film package 5; or a configuration which reduces variation resistance value among the plurality of wires in the flexible printed circuit boards 10.
(Variation 7)
Next, a variation of the display panel module according to the present embodiment is described with reference to
As shown in
(Variation 8)
Next, another variation of the display panel module according to the present embodiment is described with reference to
As shown in
As shown in
Generally, a minimum wiring pitch on Tape Career Package (TCP) or Chip On Film (COF), which is used as the film package 5, is currently approximately 25 μm to 30 μm at mass production level, whereas the minimum wiring pitch in the flexible printed circuit board 10 is approximately 50 μm to 60 μm. Here, as shown in
According to the configuration shown in
In addition, although not shown, according to the present embodiment, as in the second embodiment described above, it is also possible to provide a configuration in which the film package 5 and the display panel 9 are connected to each other via the two separate flexible printed circuit boards 10a and 10b provided in between; or as in the third embodiment described above, it is also possible to provide a configuration in which, in the flexible printed circuit board 10, a side to be connected to the display panel 9 is divided by the slit. Furthermore, as in the first to the third embodiments described above, it is also possible to provide: a configuration which includes the flexible printed circuit board 10, or the separate flexible printed circuit boards 10a and 10b having a trapezoidal shape; a configuration which enhances heat dissipation characteristics by providing, in contact with the chassis portion 11 in the display panel module, the driving circuit element 6 mounted on the film package 5; a configuration which includes a plurality of circuit elements mounted on one film package 5; a configuration in which the connecting portion 101 for connecting to the flexible printed circuit board 10, or the connecting portions 101a and 101b for connecting to the separate flexible printed circuit boards 10a and 10b are provided along three sides of the film package 5; or a configuration which reduces variation in resistance value among the plurality of wires in the flexible printed circuit board 10, or the separate flexible printed circuit boards 10a and 10b.
Thus far, although a panel display module and a display apparatus according to the present invention have been described based on some embodiments, the present invention is not limited to these embodiments. Various variations and modifications by those skilled in the art would be possible within the scope of the present invention, without departing from the scope of the present invention. In addition, each constituent element in a plurality of embodiments may be arbitrarily combined within a scope not departing from the scope of the present invention.
For example, in the above embodiments, the area of the connecting portion 101 in the film package 5, which is for connecting to the flexible printed circuit board 10, is provided along one or three sides. In other words, the electrodes 301 in the flexible printed circuit board 10 have been described as being connected to one or three different sides of the film package 5. However, as shown in the plan view of the display panel module in
In addition, in the above embodiments, the film package 5 has been described as an example of the flexible printed circuit board on which circuit elements for output of pixel data are mounted, but the film package is not limited to this.
In addition, in the above embodiments, the chassis portion 11 has been described as a material having high heat dissipation characteristics which is provided in contact with the driving circuit element 6 in the film package 5, but the material may also be a heat-dissipating sheet provided in the display apparatus.
The present invention, in order to achieve reduction in costs for a display panel module, can solve the conventional problems of increase in area of a wiring region in the display panel and heat generation in the driving circuit element in the display panel module, and is useful for a flat panel display apparatus such as a liquid crystal panel.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-280275 | Dec 2009 | JP | national |
This is a continuation application of PCT application No. PCT/JP2010/006389 filed on Oct. 29, 2010, designating the United States of America.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2010/006389 | Oct 2010 | US |
| Child | 13155815 | US |
