1. Field of the Invention
The present invention relates to display units such as electronic paper and flat panel displays and methods of manufacturing the same.
2. Description of the Related Art
In these years, electronic paper has drawn attention as an alternative information medium to paper. Electronic paper is an electronic information medium that can be bent, rolled, and carried like paper. Display systems for electronic paper include liquid crystal systems and electrophoretic systems. There are challenges such as improvement in visibility and improvement in power efficiency in putting electronic paper to practical use.
It is known that “reflection-type” display units using reflected light in displaying are better in visibility than “transmission-type” display units using transmitted light in displaying. Further, the power efficiency of a display unit is increased by employment of a display element having a “memory characteristic” that causes the contents of a display to be maintained even when power is switched from ON to OFF. Therefore, electronic paper using a cholesteric liquid crystal, which is a reflection type and has a memory characteristic, has drawn attention (Patent Document 3).
Patent Document 1: Japanese Laid-Open Patent Application No. 2000-241828
Patent Document 2: Japanese Laid-Open Patent Application No. 2002-72244
Patent Document 3: Japanese Laid-Open Patent Application No. 2003-195261
Three scanning drivers 132 and three signal drivers 133 are mounted on the display unit 101 of
The signal drivers 133 and the scanning drivers 132 contribute to an increase in the cost of the display panels 111. Therefore, while the signal driver 133 should be provided for each display panel 111, the scanning driver 132 does not have to be provided for every display panel 111. Accordingly, it is convenient if it is possible to reduce the number of scanning drivers 132 used by enabling two or more of the display panels 111 to share the single scanning driver 132.
According to one aspect of the present invention, there are provided a display unit and a method of manufacturing the same in which one or more of the above-described problems may be solved or reduced.
According to one aspect of the present invention, there is provided a display unit having a stacked display panel, the display unit including a first end display panel placed at one end; a second end display panel placed at another end; and one or more internal display panels placed between the first end display panel and the second end display panel, wherein the first end display panel includes a scan electrode terminal longer than scan electrode terminals of the internal display panels, and the second end display panel includes a scan electrode terminal longer than the scan electrode terminal of the first end display panel, and a terminal surface of the scan electrode terminal in the first end display panel faces a terminal surface of the scan electrode terminal in the second end display panel; the scan electrode terminal of each of the internal display panels is joined to the scan electrode terminal of one of the first end display panel, the second end display panel, and another one of the internal display panels; the scan electrode terminal of the first end display panel is joined to the scan electrode terminal of the second end display panel; and the scan electrode terminal of the second end display panel is connected to a scanning driver circuit.
According to one aspect of the present invention, there is provided a method of manufacturing a display unit having a stacked display panel, the display unit including a first end display panel placed at one end; a second end display panel placed at another end; and one or more internal display panels placed between the first end display panel and the second end display panel, the first end display panel including a scan electrode terminal longer than scan electrode terminals of the internal display panels, the second end display panel including a scan electrode terminal longer than the scan electrode terminal of the first end display panel, the method including causing a terminal surface of the scan electrode terminal in the first end display panel to face a terminal surface of the scan electrode terminal in the second end display panel; joining the scan electrode terminal of each of the internal display panels to the scan electrode terminal of one of the first end display panel, the second end display panel, and another one of the internal display panels; joining the scan electrode terminal of the first end display panel to the scan electrode terminal of the second end display panel; and connecting the scan electrode terminal of the second end display panel to a scanning driver circuit.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:
A description is given, with reference to the accompanying drawings, of embodiments of the present invention.
The display layer 121 is a liquid crystal layer formed of a liquid crystal forming a cholesteric phase. The display layer 121 may be a liquid crystal layer formed principally of a cholesteric liquid crystal or a liquid crystal layer formed of a nematic liquid crystal containing a cholesteric liquid crystal (a chiral dopant). As a result, a reflection-type display layer (display unit) having a memory characteristic is realized, so that improvement in the visibility and improvement in the power efficiency of electronic paper are realized.
The scan electrode 122 is a transparent electrode for applying a scan voltage to the display layer 121. The signal electrode 123 is a transparent electrode for applying a signal voltage (data voltage) to the display layer 121. Here, the scan electrode 122 and the signal electrode 123 are matrix-driving electrodes ((A) of
The scan electrode terminal 124 is a terminal for connecting the scan electrode 122 and the scanning driver 132. The signal electrode terminal 125 is a terminal for connecting the signal electrode 123 and the signal driver 133. The scan electrode terminal 124 and the signal electrode terminal 125 are IZO electrodes, but may also be ITO electrodes.
The scan electrode substrate 126 is a transparent, flexible substrate on which the scan electrode 122 and the scan electrode terminal 124 are formed. The signal electrode substrate 127 is a transparent, flexible substrate on which the signal electrode 123 and the signal electrode terminal 125 are formed. The scan electrode substrate 126 and the signal electrode substrate 127 are flexible substrates that can be bent and rolled, thereby realizing flexible electronic paper that can be bent and rolled. Here, the scan electrode substrate 126 and the signal electrode substrate 127 are polycarbonate printed boards.
The scanning driver 132 and the signal drivers 133 are mounted on the display unit 101 of
The single scanning driver 132 and the three signal drivers 133 are mounted on the display unit 101. The scanning driver 132 is common to all the display panels 111, while the signal drivers 133 are provided individually for the corresponding display panels 111.
A description is given below of the laminated structure of the display panels 111.
In the display unit 101 of
In the display unit 101 of
In the display unit 101 of
In the display unit 101 of
In the display unit 101 of
The display panel 111 has a substantially rectangular shape. One set of scan electrode terminals 124 is formed on one short side A of the four sides of the display panel 111. Two sets of signal electrode terminals 125 are formed on one long side B of the four sides of the display panel 111. The display panel 111 has substantially the same shape except for the length of the scan electrode terminal 124 in each layer. The length of the scan electrode terminal 124 is 4 mm in the lower-layer display panel 111R, 2 mm in the intermediate-layer display panel 111G, and 6 mm in the upper-layer display panel 111B, including a margin.
The top-bottom orientation in the lower-layer display panel 111R and the top-bottom orientation in the upper-layer display panel 111B are opposite to each other. As a result, it is possible to cause the terminal surface SR of the scan electrode terminal 124R in the lower-layer display panel 111R and the terminal surface SB of the scan electrode terminal 124B in the upper-layer display panel 111B to face each other.
The three display panels 111 are stacked so that the scan electrode terminals 124 of the display panels 111 are on the sides of the display panels 111 on the same side. The four sides of each display panel 111 are positioned on the right side, the left side, the front side, and the bottom side in the drawing, and the scan electrode terminals 124 of the display panels 111 are on the sides on the right side in the drawing. This makes it possible to bond the scan electrode terminals 124 of the display panels 111 to each other.
The scanning driver 132 is placed opposite to the sides of the display panels 111 on which the respective scan electrode terminals 124 are provided. That is, the scanning driver 132 is placed opposite to the right-side one of the four sides of each display panel 111 in the drawing. This makes it possible to place the scanning driver 132 in the vicinity of the sides of the display panels 111 on which the respective scan electrode terminals 124 are provided, and to bond a terminal TM of the scanning driver 132 and the scan electrode terminal 124R of the upper-layer display panel 111R to each other. Here, the term “vicinity” means a range of distances within which it is possible to bond the terminal TM of the scanning driver 132 and the scan electrode terminal 124R of the upper-layer display panel 111R to each other.
In order to make it possible to realize these, the arrangement of the scan electrode terminals 124 of the display panel 111 is axisymmetric with respect to a long axis X of the screen of the display panel 111 (
Accordingly, the display unit 101 of this embodiment corrects the orientations of the input images 151 input to the signal drivers 133 with image processing ICs 161 so that the output images 152 output from the signal drivers 133 to the display panels 111 are oriented so as to match the orientation of the display image 153 in the face-up display panel 111 with the orientation of the display image 153 in the face-down display panel 111. In
In the above, a three-layer laminated structure is taken as an embodiment of the present invention. In the following, multilayer laminated structures having three or more layers ate taken as variant embodiments of the present invention.
In the display units 101 of
In the display unit 101 of each drawing, the terminal surface SR of the scanning electrode terminal 124R in the lower-layer display panel 111R faces the terminal surface SB of the scanning electrode terminal 124B in the upper-layer display panel 111B. This is for bonding the scan electrode terminal 124R of the lower-layer display panel 111R to the scan electrode terminal 124B of the upper-layer display panel 111B with the anisotropic conductive adhesive agent 134 as shown in each drawing. Therefore, the length LR of the scan electrode terminal 124R in the lower-layer display panel 111R and the length LB of the scan electrode terminal 124B in the upper-layer display panel 111B are both greater than lengths LGa and LGb of scan electrode terminals 124Ga and 124Gb in the intermediate-layer display panels 111Ga and 111Gb.
In the display unit 101 of each drawing, terminal surfaces SGa and SGb of the scan electrode terminals 124Ga and 124Gb in the intermediate-layer display panels 111Ga and 111Gb may be caused to face the terminal surface SR of the scan electrode terminal 124R in the lower-layer display panel 111R or be caused to face the terminal surface SB of the scan electrode terminal 124B in the upper-layer display panel 111B. In the former case, the scan electrode terminals 124Ga and 124Gb of the intermediate-layer display panels 111Ga and 111Gh are joined to the opposing scan electrode terminal 124R, 124Gb, or 124Ga of the lower-layer or other intermediate display panel 111R, 111Gb, or 111Ga with the anisotropic conductive adhesive agent 134. In the latter case, the scan electrode terminals 124Ga and 124Gb of the intermediate-layer display panels 111Ga and 111Gb are joined to the opposing scan electrode terminal 124B, 124Gb, or 124Ga of the upper-layer or other intermediate-layer display panel 111B, 111Gb, or 111Ga with the anisotropic conductive adhesive agent 134.
In the display unit 101 of each drawing, the scan electrode terminal 124B of the upper-layer display panel 111B is joined to the terminal of the scanning driver 132 with the anisotropic conductive adhesive agent 134, so that the scan electrode terminal 124B of the upper-layer display panel 111B is connected to the scanning driver 132. Therefore, the length LB of the scan electrode terminal 124B in the upper-layer display panel 111B is greater than the length LR of the scan electrode terminal 124R in the lower-layer display panel 111R. In the case of bonding the terminal of the scanning driver 132 to the lower-layer scan electrode terminal 124R in place of the upper-layer scan electrode terminal 124B, the length LB of the upper-layer scan electrode terminal 124B and the length LR of the lower-layer scan electrode terminal 124R are reversed.
In each manufacturing method, the display panels 111 having the scan electrode terminals 124 whose lengths increase in the order of “each intermediate layer, the lower layer, and the upper layer” are prepared (
In the process of S30, the scan electrode terminal 124 of the intermediate-layer display panel 111 is bonded to the scan electrode terminal 124 of the lower-layer, upper-layer, or other intermediate-layer display panel 111 (S30-1), and finally, the scan electrode terminal 124 of the lower-layer display panel 111 is bonded to the scan electrode terminal 124 of the upper-layer display panel 111 (S30-2).
According to one aspect of the present invention, there is provided a display unit having a stacked display panel, the display unit including a first end display panel placed at one end; a second end display panel placed at another end; and one or more internal display panels placed between the first end display panel and the second end display panel, wherein the first end display panel includes a scan electrode terminal longer than scan electrode terminals of the internal display panels, and the second end display panel includes a scan electrode terminal longer than the scan electrode terminal of the first end display panel, and a terminal surface of the scan electrode terminal in the first end display panel faces a terminal surface of the scan electrode terminal in the second end display panel; the scan electrode terminal of each of the internal display panels is joined to the scan electrode terminal of one of the first end display panel, the second end display panel, and another one of the internal display panels; the scan electrode terminal of the first end display panel is joined to the scan electrode terminal of the second end display panel; and the scan electrode terminal of the second end display panel is connected to a scanning driver circuit.
According to one aspect of the present invention, there is provided a method of manufacturing a display unit having a stacked display panel, the display unit including a first end display panel placed at one end; a second end display panel placed at another end; and one or more internal display panels placed between the first end display panel and the second end display panel, the first end display panel including a scan electrode terminal longer than scan electrode terminals of the internal display panels, the second end display panel including a scan electrode terminal longer than the scan electrode terminal of the first end display panel, the method including causing a terminal surface of the scan electrode terminal in the first end display panel to face a terminal surface of the scan electrode terminal in the second end display panel; joining the scan electrode terminal of each of the internal display panels to the scan electrode terminal of one of the first end display panel, the second end display panel, and another one of the internal display panels; joining the scan electrode terminal of the first end display panel to the scan electrode terminal of the second end display panel; and connecting the scan electrode terminal of the second end display panel to a scanning driver circuit.
Thus, according one aspect of the present invention, there are provided a non-conventional, novel method for reducing the number of scanning driver circuits used with respect to a display unit having a stacked display panel and a method of manufacturing the same.
The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention.
The present application is a continuation application filed under 35 U.S.C. 111(a) claiming benefit under 35 U.S.C. 120 and 365(c) of PCT International Application No. PCT/JP2005/004911, filed on Mar. 18, 2005, the entire contents of which are hereby incorporated by reference.
Number | Date | Country | |
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Parent | PCT/JP2005/004911 | Mar 2005 | US |
Child | 11856927 | Sep 2007 | US |