1. Field of the Invention
The present invention relates to a display device, and particularly to a liquid crystal display device with a built-in sensor array having a touch panel function.
2. Description of the Background Art
A conventional liquid crystal display device with a built-in sensor array includes a plurality of source lines formed by being extended in a row direction within a display screen, a plurality of gate lines formed by being extended in a column direction within the display screen, pixel sensors each arranged at an intersection of each of the source lines and gate lines, a plurality of signal lines formed by being extended in the row direction, and integrators connected to the signal lines. Each of the signal lines is connected to a plurality of pixel sensors belonging to the same row as each of the signal lines. By sequential driving of the plurality of gate lines, a signal sent from a pixel sensor on each row corresponding to the gate line being driven, through the signal line on each row, is read with the integrator on each row.
It is to be noted that a technique on a liquid crystal display device, in which a light sensor is formed on each of a plurality of pixels arranged in matrix form and which has the function of detecting a position coordinate within a display screen pointed with a light pen is for example disclosed in Japanese Patent Application Laid-Open No. 04-222018 (1992).
As thus described, in the conventional liquid crystal display device with a built-in sensor array, the integrators are each arranged corresponding to each of the plurality of signal lines. Hence, there is a problem in that, when the number of signal lines increases due to upsizing or resolution improvement of the display screen, the number of integrators also increases in proportion to the signal line increase, which may incur cost rise.
An object of the present invention is to obtain a display device capable of reducing cost by reduction in number of integrators.
According to a first aspect of the present invention, a display device includes first and second source lines, a gate line, first and second pixel sensors, first and second signal lines, an integrator, and a selector. The first and second source lines are formed within a display screen. The gate line is formed within the display screen and is orthogonal to the first and second source lines. The first pixel sensor is arranged corresponding to an intersection of the first source line and the gate line. The second pixel sensor is arranged corresponding to an intersection of the second source line and the gate line. The first signal line is connected to the first pixel sensor. The second signal line is connected to the second pixel sensor. The selector selectively connects the first and second signal lines to the integrator.
It is possible to reduce the number of integrators.
According to a second aspect of the present invention, a display device includes first to fourth source lines, a gate line, first to fourth pixel sensors, first to fourth signal lines, an integrator, and first to third selectors. The first to fourth source lines are formed within a display screen. The gate line is formed within the display screen and is orthogonal to the first to fourth source lines. The first pixel sensor is arranged corresponding to an intersection of the first source line and the gate line. The second pixel sensor is arranged corresponding to an intersection of the second source line and the gate line. The third pixel sensor is arranged corresponding to an intersection of the third source line and the gate line. The fourth pixel sensor is arranged corresponding to an intersection of the fourth source line and the gate line. The first signal line is connected to the first pixel sensor. The second signal line is connected to the second pixel sensor. The third signal line is connected to the third pixel sensor. The fourth signal line is connected to the fourth pixel sensor. The first selector is connected to the integrator. The second selector selectively connects the first and second signal lines to the first selector. The third selector selectively connects the third and fourth signal lines to the first selector. The first selector selectively connects the second and third selectors to the integrator.
It is possible to reduce the number of integrators.
According to a third aspect of the present invention, a display device includes first to fourth source lines, first and second gate lines, first to fourth pixel sensors, first to sixth signal lines, an integrator, and a selector. The first to fourth source lines are formed within a display screen. The first and second gate lines are formed within the display screen, are orthogonal to the first to fourth source lines, and are driven in sequence. The first pixel sensor is arranged corresponding to an intersection of the first source line and the first gate line. The second pixel sensor is arranged corresponding to an intersection of the second source line and the second gate line. The third pixel sensor is arranged corresponding to an intersection of the third source line and the first gate line. The fourth pixel sensor is arranged corresponding to an intersection of the fourth source line and the second gate line. The first signal line is connected to the first pixel sensor. The second signal line is connected to the second pixel sensor. The third signal line is connected to the third pixel sensor. The fourth signal line is connected to the fourth pixel sensor. The fifth signal line is connected to the first and second signal lines. The sixth signal line is connected to the third and fourth signal lines. The selector selectively connects the fifth and sixth signal lines to the integrator.
It is possible to reduce the number of integrators.
According to a fourth aspect of the present invention, a display device includes first to fourth source lines, first and second gate lines, first to fourth pixel sensors, first to fourth signal lines, an integrator, and a selector. The first to fourth source lines are formed within a display screen. The first and second gate line are formed within the display screen, are orthogonal to the first to fourth source lines, and are driven in sequence. The first pixel sensor is arranged corresponding to an intersection of the first source line and the first gate line. The second pixel sensor is arranged corresponding to an intersection of the second source line and the first gate line. The third pixel sensor is arranged corresponding to an intersection of the third source line and the second gate line. The fourth pixel sensor is arranged corresponding to an intersection of the fourth source line and the second gate line. The first signal line is connected to the first pixel sensor. The second signal line is connected to the second pixel sensor. The third signal line is connected to the third pixel sensor. The fourth signal line is connected to the fourth pixel sensor. The selector selectively connects the first and second signal lines to the integrator, and selectively connects the third and fourth signal lines to the integrator.
It is possible to reduce the number of integrators.
According to a fifth aspect of the present invention, a display device includes first and second source lines, first and second gate lines, first and second pixel sensors, first and second signal lines, and an integrator.
The first and second source lines are formed within a display screen. The first and second gate lines are formed within the display screen, are orthogonal to the first and second source lines, and are driven in sequence. The first pixel sensor is arranged corresponding to an intersection of the first source line and the first gate line. The second pixel sensor is arranged corresponding to an intersection of the second source line and the second gate line. The first signal line is connected to the first pixel sensor. The second signal line is connected to the second pixel sensor. The integrator is connected to the first and second signal lines.
It is possible to reduce the number of integrators.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
At each of intersections of the source lines 51 to 516 and the gate lines 61 to 616, a pixel having an amorphous silicon thin film transistor (hereinafter, referred to as “a-SiTFT”) is arranged. A gate electrode of the a-SiTFT is connected to each of the gate lines 61 to 616, and a source electrode thereof is connected to each of the source lines 51 to 516. In each of the pixels, an arbitrary type pixel sensor 8, such as a photo-sensor, is formed. It is to be noted that, in
A plurality of signal lines 91 to 916 are formed by being extended in the row direction, corresponding to the source lines 51 to 516. Each of the signal lines 91 to 916 is connected to a plurality (16 in the example shown in
A plurality of selector lines 71 to 74, orthogonal to the signal lines 91 to 916, are formed and connected to a selector driving circuit 3. The a-SiTFT 12 is formed at each of intersections of the selector line 71 and the signal lines 91, 95, 99, 913, intersections of the selector line 72 and the signal lines 92, 96, 910, 914, intersections of the selector line 73 and the signal lines 93, 97, 911, 915, and intersections of the selector line 74 and the signal lines 94, 98, 912, 916. For example, the a-SiTFT 12 formed at the intersection of the selector line 71 and the signal line 91 has a gate electrode connected to the selector line 71 and a source electrode and a drain electrode which are connected to the signal line 91. The a-SiTFT 12 is turned on by driving of the selector line 71 by the selector driving circuit 3, to bring the signal line 91 into conduction.
Since four a-SiTFTs 12 are connected to the selector line 71, the signal lines 91, 95, 99, 913 are concurrently brought into conduction by driving of the selector line 71. This applies to the other selector lines 72 to 74. The signal lines 92, 96, 910, 914 are concurrently brought into conduction by driving of the selector line 72. The signal lines 93, 97, 911, 915 are concurrently brought into conduction by driving of the selector line 73. The signal lines 94, 98, 912, 916 are concurrently brought into conduction by driving of the selector line 74.
The a-SiTFT 12 arranged at each of intersections of the selector lines 71 to 74 and the signal lines 91 to 916 outside the display screen can be formed in the same process as the a-SiTFT 12 arranged at each of the intersections of the source lines 51 to 516 and the gate lines 61 to 616 within the display screen. Namely, a change in mask pattern allows formation of the a-SiTFTs 12 outside the display screen concurrently with the formation of the a-SiTFTs within the display screen in the array production process. This can reduce production cost as compared to the case of forming the a-SiTFTs 12 in a separate process from the formation process for the a-SiTFTs within the display screen. This also applies to second to eighth embodiments to be described later.
As thus described, according to the liquid crystal display device with a built-in sensor array of the first embodiment, the signal lines 91 to 94, 95 to 98, 99 to 912, 913 to 916 are respectively brought together by means of the signal lines 10a, 10b, 10c, 10d, to be connected to the integrators 4a, 4b, 4c, 4d. Hence, arrangement of the total four integrators 4a to 4d is sufficient with respect to the total sixteen signal lines 91 to 916. This can result in reduction in number of integrators, which permits an attempt to reduce cost, as compared to the case of arrangement of the integrator on every signal line.
Similarly to the liquid crystal display device according to the first embodiment, it is also possible to reduce the number of integrators according to the liquid crystal display device with a built-in sensor array of the second embodiment since arrangement of the total four integrators 4a to 4d is sufficient with respect to the total sixteen signal lines 91 to 916, thereby permitting an attempt to reduce cost.
Eight selector lines 71 to 78, orthogonal to the signal lines 91 to 916, are formed and connected to the selector driving circuit 3. The a-SiTFT 12 is formed at each of intersections of the selector line 71 and the signal lines 91, 99, intersections of the selector line 72 and the signal lines 92, 910, intersections of the selector line 73 and the signal lines 93, 911, intersections of the selector line 74 and the signal lines 94, 912, intersections of the selector line 75 and the signal lines 95, 913, intersections of the selector line 76 and the signal lines 96, 914, intersections of the selector line 77 and the signal lines 97, 915, and intersections of the selector line 78 and the signal lines 98, 916.
As in the case of the liquid crystal display device according to the first embodiment, the selector driving circuit 3 drives the selector lines 71 to 78 in sequence in the frame period. Alternatively, as in the case of the liquid crystal display device according to the second embodiment, the selector driving circuit 3 drives the selector lines 71 to 78 in sequence in the gate period. In either case, signals respectively detected with all the pixel sensors 8 within the display screen during eight frame periods from the first frame F1 to the eighth frames F8 are read with the integrators 4ab, 4cd.
According to the configuration shown in
Selector lines 171, 172, orthogonal to the signal lines 15a to 15d, are formed and connected to the selector driving circuit 3. An a-SiTFT 18 is formed at each of intersections of the selector line 171, and the signal lines 15a, 15c, and intersections of the selector line 172 and the signal lines 15b, 15d. For example, the a-SiTFT 18 formed at the intersection of the selector line 171 and the signal line 15a has a gate electrode connected to the selector line 171 and a source electrode and a drain electrode which are connected to the signal line 15a. The a-SiTFT 18 is turned on by driving of the selector line 171 by the selector driving circuit 3, to bring the signal line 15a into conduction.
Since two a-SiTFTs 18 are respectively connected to the selector lines 171, 172, the signal lines 15a, 15c are concurrently brought into conduction by driving of the selector line 171, and the signal lines 15b, 15d are concurrently brought into conduction by driving of the selector line 172. As in the case of the a-SiTFT 12, the a-SiTFT 18 can be formed in the same process as the a-SiTFT arranged at each of the intersections of the source lines 51 to 516 and the gate lines 61 to 616 within the display screen. Namely, a change in mask pattern allows formation of the a-SiTFTs 12, 18 outside the display screen concurrently with the formation of the a-SiTFT within the display screen in the array production process.
It is to be noted that, although the example is described above in which the selector driving circuit 3 drives the selector lines 71 to 74, 171, 172 in sequence in the frame period as in the case of the liquid crystal display device according to the first embodiment, the selector driving circuit 3 may drive the selector lines 71 to 74, 171, 172 in sequence in the gate period as in the case of the liquid crystal display device according to the second embodiment.
Further, although
As thus described, according to the liquid crystal display device with a built-in sensor array of the third embodiment, the signal lines 91 to 98 are brought together into one line by means of the signal lines 10a, 10b, 16ab, to be connected to the integrator 4ab. Further, the signal lines 99 to 916 are brought together into one line by means of the signal lines 10c, 10d, 16cd, to be connected to the integrator 4cd. Therefore, arrangement of the total two integrators 4ab and 4cd is sufficient with respect to the total sixteen signal lines 91 to 916. This can result in reduction in number of integrators, which permits an attempt to reduce cost, as compared to the configuration shown in
Moreover, since the six selector lines 71 to 74, 171, 172 are sufficient in number, it is possible to reduce the number of selector lines from the configuration shown in
Further, in the liquid crystal display device with a built-in sensor array according to the fourth embodiment, the selector driving circuit 3, the selector lines 71 to 74 and the a-SiTFT 12 shown in
Similarly to the above, the gate driving circuit 2 drives the gate lines 61 to 616 in sequence in a prescribed gate period. In the case where the gate line 61 is being driven, for example, respective signals detected with the pixel sensors 8 arranged at intersections of the source lines 54, 58, 512, 516 and the gate line 61 are read with the integrators 4a, 4b, 4c, 4d. Further, in the case where the gate line 62 is being driven, for example, respective signals detected with the pixel sensors 8 arranged at intersections of the source lines 53, 57, 511, 515 and the gate line 62 are read with the integrators 4a, 4b, 4c, 4d. Consequently, in the liquid crystal display device with a built-in sensor array according to the fourth embodiment, signals respectively detected with all the pixel sensors 8 within the display screen during one frame period are read with the integrators 4a to 4d.
According to the liquid crystal display device with a built-in sensor array of the fourth embodiment, by reduction in number of pixel sensors 8 to be arranged within the display screen, the number of integrators to be arranged with respect to the total sixteen signal lines 91 to 916 can be reduced to four, without the necessity to arrange the selector driving circuit 3 and the selector line 71 to 74 shown in
Moreover, since there is no need for arranging the selector driving circuit 3 and the selector lines 71 to 74 shown in
Four selector lines 71 to 74, orthogonal to the signal lines 11a to 11d, are formed and connected to the selector driving circuit 3. An a-SiTFT 12 is formed at each of an intersection of the selector line 71 and the signal line 11a, an intersection of the selector line 72 and the signal line 11b, an intersection of the selector line 73 and the signal line 11c, and an intersection of the selector line 74 and the signal line 11d. For example, the a-SiTFT 12 formed at the intersection of the selector line 71 and the signal line 11a has a gate electrode connected to the selector line 71 and a source electrode and a drain electrode which are connected to the signal line 11a. The a-SiTFT 12 is turned on by driving of the selector line 71 by the selector driving circuit 3, to bring the signal line 11a into conduction. In the same manner, the signal lines 11b, 11c, 11d are brought into conduction by driving of the selector lines 72, 73, 74, respectively.
The selector driving circuit 3 may drive the selector lines 71 to 74 in sequence in the frame period as in the case of the liquid crystal display device according to the first embodiment, or may drive the selector lines 71 to 74 in sequence in the gate period as in the case of the liquid crystal display device according to the second embodiment. For example in the case where the selector lines 71 to 74 are driven in the frame period, signals detected with total sixteen pixel sensors 8 connected to the signal lines 91 to 94 are read with the integrator 4 in the first frame F1, signals detected with total sixteen pixel sensors 8 connected to the signal lines 95 to 98 are read with the integrator 4 in the second frame F2, signals detected with total sixteen pixel sensors 8 connected to the signal lines 99 to 912 are read with the integrator 4 in the third frame F3, and signals detected with total sixteen pixel sensors 8 connected to the signal lines 913 to 916 are read with the integrator 4 in the fourth frame F4. Consequently, the signals respectively detected with all the pixel sensors 8 within the display screen are read with the integrator 4 during four frame periods from the first frame F1 to the fourth frame F4.
As thus described, according to the liquid crystal display device with a built-in sensor array of the fifth embodiment, the signal lines 91 to 916 are ultimately brought together into one signal line 21, to be connected to the integrator 4. Therefore, arrangement of only one integrator 4 is sufficient with respect to the total sixteen signal lines 91 to 916. This can result in reduction in number of integrators, which permits an attempt to reduce cost, as compared to the configuration shown in
It is to be noted that, although the combinations of the liquid crystal display devices according to the first or second embodiment and the liquid crystal display device according to the fourth embodiment are described, it goes without saying that it is also possible to combine the liquid crystal display device according to the third embodiment with the liquid crystal display device according to the fourth embodiment.
The signal lines 91 to 916 are connected to a signal line 25, and this signal line 25 is connected to an integrator 4 through a signal line 26. Namely, the sixteen signal lines 91 to 916 are brought together into one line by means of the signal line 25, to be connected to one integrator 4.
As in the configuration shown in
The selector driving circuit 3 may drive the selector lines 71 to 74 in sequence in the frame period as in the case of the liquid crystal display device according to the first embodiment, or may drive the selector lines 71 to 74 in sequence in the gate period as in the case of the liquid crystal display device according to the second embodiment. For example in the case where the selector lines 71 to 74 are driven in the frame period, signals detected with total sixteen pixel sensors 8 connected to the signal lines 91, 95, 99, 913 are read with the integrator 4 in the first frame F1, signals detected with total sixteen pixel sensors 8 connected to the signal lines 92, 96, 910, 914 are read with the integrator 4 in the second frame F2, signals detected with total sixteen pixel sensors 8 connected to the signal lines 93, 97, 911, 915 are read with the integrator 4 in the third frame F3, and signals detected with total sixteen pixel sensors 8 connected to the signal lines 94, 98, 912, 916 are read with the integrator 4 in the fourth frame F4. Consequently, the signals respectively detected with all the pixel sensors 8 within the display screen are read with the integrator 4 during four frame periods from the first frame F1 to the fourth frame F4.
As thus described, according to the liquid crystal display device with a built-in sensor array of the sixth embodiment, the signal lines 91 to 916 are ultimately brought together into one signal line 26, to be connected to the integrator 4. Therefore, arrangement of only one integrator 4 is sufficient with respect to the total sixteen signal lines 91 to 916. This can result in reduction in number of integrators, which permits an attempt to reduce cost, as compared to the configuration shown in
Moreover, since there is no need for securing a region for forming the signal lines 10a to 10d, it is possible to attempt size reduction of the device as a whole, as compared to the configuration shown in
Furthermore, in the configuration shown in
It is to be noted that the liquid crystal display device according to the sixth embodiment can be combined with the liquid crystal display device according to the third embodiment.
An a-SiTFT 12 is formed at each of an intersection of the selector line 711 and the signal line 91, an intersection of the selector line 712 and the signal line 95, an intersection of the selector line 713 and the signal line 99, an intersection of the selector line 714 and the signal line 913, an intersection of the selector line 721 and the signal line 92, an intersection of the selector line 722 and the signal line 96, an intersection of the selector line 723 and the signal line 910, an intersection of the selector line 724 and the signal line 914, an intersection of the selector line 731 and the signal line 93, an intersection of the selector line 732 and the signal line 97, an intersection of the selector line 733 and the signal line 911, an intersection of the selector line 734 and the signal line 915, an intersection of the selector line 741 and the signal line 94, an intersection of the selector line 742 and the signal line 98, an intersection of the selector line 743 and the signal line 912, and an intersection of the selector line 744 and the signal line 916. As thus described, only one a-SiTFT 12 is connected to each of the selector line 711 to 714, 721 to 724, 731 to 734, 741 to 744.
As thus described, according to the liquid crystal display device with a built-in sensor array of the seventh embodiment, the signal lines 91 to 916 are ultimately brought together into one signal line 26, to be connected to the integrator 4. Therefore, arrangement of only one integrator 4 is sufficient with respect to the total sixteen signal lines 91 to 916. This can result in reduction in number of integrators, which permits an attempt to reduce cost, as compared to the configuration shown in
Moreover, only one a-SiTFT 12 is connected to one selector line in the liquid crystal display device with a built-in sensor array according to the seventh embodiment, whereas the four a-SiTFTs 12 are connected to one selector line in the configuration shown in
It is to be noted that the liquid crystal display device according to the seventh embodiment can be combined with the liquid crystal display device according to the third embodiment.
Since the pixel sensors 8 are not arranged in the region of the upper half of the display screen, it is possible to omit the arrangement of the signal lines 10a, 10b, 11a, 11b, the eight a-SiTFTs 12 corresponding to the signal lines 91 to 98, and the integrators 4a, 4b, which are shown in
It should be noted that, although the example is described above in which the pixel sensors 8 are arranged only in the region of the lower half of the display screen, a region where the pixel sensors 8 are to be arranged is not limited to the lower half of the display screen, and may be an arbitrary region with respect to the column direction, such as the upper half or the central part of the display screen. Alternatively, the pixel sensors 8 may for example be arranged on every other line according to application.
Further, although the example is described above in which the invention according to the eighth embodiment is applied to the liquid crystal display device according to the first embodiment, the invention according to the eighth embodiment can also be applied to any of the liquid crystal display devices according to the second to seventh embodiments.
As thus described, according to the liquid crystal display device with a built-in sensor array according to the eighth embodiment, the pixel sensors 8 are not arranged on the whole of the display screen, but arranged only in a region in part of the display screen. It is therefore possible to omit arrangement of the integrator corresponding to the region where the pixel sensor 8 is not arranged, thereby allowing an attempt to reduce cost.
While the invention has been shown and described in detail, the foregoing description is in all aspects illustrative and not restrictive. It is therefore understood that numerous modifications and variations can be devised without departing from the scope of the invention.
Number | Date | Country | Kind |
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2005-146546 | May 2005 | JP | national |