JPH0718989B2 - Liquid crystal display device for projection - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention is used, for example, in a projection type television receiver,
The present invention relates to a liquid crystal display device which is used as a display surface, that is, an original image when a small display surface is enlarged and projected by optical means such as a lens for viewing.

[Prior art]

A projection type television receiver is called a front projector type, and a liquid crystal display device 21 which is an original image is projected from the front of a reflection type screen 11 as shown in FIG. In some cases, the liquid crystal display device 22 is projected from the rear of the transmissive screen 12 as shown in the figure. At this time, the front projector type liquid crystal display device 21 and the rear projector type liquid crystal display device 22 are the original images. It is necessary to use those with the left and right directions reversed.

[Problems to be Solved by the Invention]

However, whether it is used as the front projector type or the rear projector type is determined by the user's condition such as the size of the room to be used, and may be changed depending on the change of the condition. Therefore, it is inconvenient for the user side to be limited to any one of the above-mentioned projection methods, and for the manufacturer side, only the above-mentioned original image has the same structure. It is a complicated problem to manufacture two different models, both of which have problems, and the solution of these problems is a problem.

[Means for Solving the Problems]

The present invention, as a concrete means for solving the above-described problems that occur in a conventional liquid crystal display device using a TFT liquid crystal panel, in the source line of the liquid crystal panel, two sets of source line drivers are arranged in parallel. And a liquid crystal display device for projection, which is characterized in that they are connected so as to be driven in the reverse order, so that both the front projector type and the rear projector type can be used, It solves the problem.

【Example】

Next, the present invention will be described in detail based on an embodiment shown in the drawings. Reference numeral 1 in FIG. 1 denotes a projection liquid crystal display device according to the present invention, and a TFT liquid crystal panel 2 (TFT = thin film transistor, hereinafter referred to as a liquid crystal panel 2) of this projection liquid crystal display device 1.
Is abbreviated. ) The gate line G ₁ ~
Source line terminal 2c to the same source line S ₁ to S _n and the gate line terminal 2b which G ₂ is drawn out is drawn out in the same order, 2d
And a gate line driver 3 is connected to the gate line terminal 2b using a flexible printed circuit board FPCB or the like, and the source line terminals 2c and 2d are a forward source line driver 4 and a backward source line driver 5 respectively. Flexible printed circuit board FPCB
Are connected using. FIG. 2 is a wiring diagram showing the connection states of the source lines S _{1 to} S _n with the forward source line driver 4 and the backward source line driver 5 in more detail. The forward source line driver 4 is shown in FIG. by sampling the input data dATA in the direction indicated by the arrow X, and outputs at its output terminal O ₁ ~ O _n, wherein the output terminal O ₁ ~ O _n is the the source line S ₁ to S _n In the same order, that is, O ₁ and S ₁ , O ₂ and S ₂ , ...
.., O _n and S _n are connected so as to form a pair, whereas the reverse source line driver 5 samples the input data DATA in the direction indicated by the arrow Y in the figure and outputs it at its output terminal O. _{1 to} O _n , and the reverse order of the source lines S _{1 to} S _n , that is, O ₁ and S _n , O ₂ and S _n-1 , ...
., O _n and S ₁ are connected to form a pair. Further, the in the forward direction to the output terminal O ₁ ~ O _n of the respective source line driver 4 and the reverse source line driver 5 instructs the output / prohibition OE (output enable) terminal, the forward source line driver 4 Is directly applied with a control signal CTL, and the same control signal CTL is applied to the OE terminal of the reverse direction source line driver 5 via an inversion gate RG. Next, the projection liquid crystal display device 1 of the present invention thus configured
The operation of the positive direction source line driver 4 will be explained if "H" is applied as the control signal CTL.
The the OE terminal is applied as it is "H", the forward output terminal O ₁ ~ O _n source line driver 4 becomes an output state, the inversion on one of the OE terminal of the reverse source line driver 5 gate RG It is applied to "L" through the output terminal O ₁ ~ O _n of the reverse source line driver 5 is held in a high impedance state and disabled state. By applying the same input data DATA to both the source line drivers 4 and 5 in the state, the only result as the output appears in the positive direction the source line output terminal O ₁ ~ O _n driver 4, the gate line driver 3 The FET connected to the intersection of the gate lines G _{1 to} G _n driven by
The pixel PC of the liquid crystal panel 2 connected to the drain of the liquid crystal panel 2 is driven, and a normal image is displayed on the display surface 2a of the liquid crystal panel 2 vertically and horizontally. Will be obtained. Further, the control signal CTL as "L" becomes an output terminal O ₁ ~ O _n output state of the reverse source line driver 5 Contrary to the description by applying a, an output terminal of said positive source line driver 4 O _{1 to} O _n are in a prohibited state, where the reverse source line driver 5 has its output terminals O _{1 to} O _n.
And the source lines S _{1 to} S _n are connected in the reverse order, so that the display surface 2a of the liquid crystal panel 2 displays a reverse image in which the vertical image is the normal image and the horizontal image is the inverted image. Therefore, an image for the rear projector can be obtained. Further, FIG. 3 shows another embodiment of the present invention,
In the previous embodiment, the source lines S _{1 to} S _n are connected to the liquid crystal panel 2.
Source line terminals that extend to both sides of the display surface 2a
Although 2c and 2d are provided, in actual implementation, only one of them may be drawn out as the source line terminal 2e. At this time, both source line drivers 4 and 5 are connected to the source line terminal 2e in front of them. It suffices to connect them by the same procedure as described in the above embodiment, and doing so does not cause any difference in action and effect. It should be noted here that it is the gist of the present invention to set a vertical image as a normal image and a horizontal direction as a reverse image means to set a vertical image as a reverse image and a horizontal direction as a normal image. Are equivalent, which means that two sets of gate line drivers are used and the same means as described above is used for this gate line G ₁
It can be implemented by applying it to ~ G _n .

【The invention's effect】

As described above, according to the present invention, the projection liquid crystal display device is connected to the source line of the TFT liquid crystal panel in such a manner that two sets of source line drivers are connected in parallel and in the reverse driving direction. It is possible to invert the left and right of the image by an extremely simple operation called switching the connection signal "H" / "L", and it can be used for both the front projector and the rear projector. This has the outstanding effect of widening the versatility of John receivers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a liquid crystal display device for projection according to the present invention, FIG. 2 is a wiring diagram showing internal connections of the same embodiment, and FIG. FIG. 4 is a cross-sectional view showing another embodiment of the invention as a main part, and FIGS. 4 and 5 are explanatory views showing a conventional example. 1 ... Projection liquid crystal display device 2 ... TFT liquid crystal panel 2a ... Display surface 2b ... Gate line terminals 2c, 2d, 2e ... Source line terminal 3 ... Gate line driver 4 ... Forward source line driver 5 ...... reverse source line driver S ₁ to S _n ...... source lines O ₁ ~ O _n ...... output terminal

Claims (1)

[Claims] 1. In a liquid crystal display device for projection using a TFT liquid crystal panel, two sets of source line drivers are connected in parallel to the source line of the liquid crystal panel so as to have driving directions in reverse order. Characteristic liquid crystal display device for projection.