JP2004252334A - Projection display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection display device with which size reduction and higher performance of the device are realized and which is manufactured at low cost. <P>SOLUTION: The projection display device is equipped with a light source 2 and a liquid crystal light valve 22 to modulate light L of the light source 2. A liquid crystal panel 35 to modulate the light and a COF (chip on film) substrate 32 with an integrated circuit chip 34 mounted on a film substrate 33 is provided on the liquid crystal light valve 22 and the liquid crystal light valve 22 is connected to an external controlling circuit via the COF substrate 32. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a projection display device.
[0002]
[Prior art]
In recent years, demands for thin display devices with high resolution, low power consumption, and high resolution have been increasing, and research and development have been promoted. 2. Description of the Related Art As one form of a display device, a projection display device (liquid crystal projector) that enlarges and projects an image emitted from an optical system using a light modulation element such as a liquid crystal light valve onto a screen through a projection lens is known. As a light modulation element of a projection display device, a digital mirror device (hereinafter abbreviated as DMD) has been put to practical use in addition to a liquid crystal light valve.
By the way, in a liquid crystal light valve or the like used as a light modulator of a projection display device as described above, there is a strong demand for cost reduction. For example, in Patent Document 1 below, a driving circuit of a liquid crystal device or a part thereof is provided. A technique is disclosed in which a liquid crystal device is mounted at a substrate sandwiching a liquid crystal, and a switching element for a pixel and a semiconductor element for a driving circuit are manufactured at the same time, thereby reducing the cost of the liquid crystal device.
[0003]
[Patent Document 1]
Japanese Patent No. 3133248 [0004]
[Problems to be solved by the invention]
According to the technique described in Patent Document 1, it is possible to realize a liquid crystal device that is superior in terms of reduction in the number of connection wirings, manufacturing efficiency of active elements, and the like, as compared with the case where a drive circuit is provided outside. However, in a liquid crystal light valve or the like mounted on a projection display device, there is a strong demand for high definition and small size. When a liquid crystal light valve in which a driving circuit is mounted on a substrate is used, (1) driving The circuit occupies a certain amount of substrate area, which hinders miniaturization. (2) The liquid crystal light valve and the control circuit are increased due to the increase in the number of connection lines between the drive circuit and an external control circuit with the increase in the definition of pixels. And (3) with the increase in the number of pixels, the capability of the drive circuit mounted on the substrate becomes insufficient.
[0005]
The present invention has been made in order to solve the above-described problems, and has as its object to provide a projection-type display device that can realize miniaturization and high performance of the device and can be manufactured at low cost. .
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a projection display device of the present invention includes a light source, a light modulation device that modulates light from the light source, and a projection device that projects light modulated by the light modulation device. A projection display device, wherein the light modulation device includes a main body for performing the light modulation, and a substrate having an integrated circuit chip mounted on a flexible substrate, and an external control circuit via the substrate. It is characterized by being connected to.
The substrate is obtained by mounting an integrated circuit chip on a flexible substrate by using a COF (Chip on film / Chip on flexible print circuit) technology, and is generally a laminated structure in which wiring is formed between layers. An opening region is provided in one of the substrates, and the integrated circuit chip is mounted on wiring extending into the opening region.
In the liquid crystal display device described in Patent Document 1, cost reduction is achieved by mounting a drive circuit on a panel. However, a projection type display in which a small and high-definition light modulator is required. In device applications, it is difficult to reduce the size of a light modulation device in a configuration in which a control circuit for driving and controlling the device is mounted on a main body portion (for example, a liquid crystal device or the like). In order to improve it, it becomes difficult to mount the drive circuit on the main body. On the other hand, in the configuration of the present invention, the integrated circuit chip for driving and controlling the light modulation device is separated from the main body of the light modulation device. By using a COF substrate on which an integrated circuit chip functioning as a high-performance driver circuit is mounted, a light modulator capable of obtaining a high-resolution display image can be easily configured. As a result, a small and high-definition light modulation device can be easily manufactured, which can contribute to a reduction in the manufacturing cost of the projection display device.
Furthermore, in the present embodiment, a projection-type display which is less likely to cause malfunction of the integrated circuit chip and has higher reliability than the case where the integrated circuit chip is mounted on a light modulator to which light from a light source is directly applied. An apparatus can be provided.
[0007]
Next, the projection display device of the present invention is characterized in that the integrated circuit chip mounted on the substrate constitutes at least a part of a drive circuit that outputs an image signal to the light modulation device. I do.
According to this configuration, among the circuits constituting the drive circuit, a circuit that requires a high performance can be mounted on the substrate, so that the performance of the drive circuit can be reduced when the optical modulation device is made finer. It can be easily improved.
[0008]
Next, in the projection type display device of the present invention, a connection terminal for connecting the substrate and the light modulation device is formed at an edge of one side of the flexible substrate, and the connection terminal and the integrated circuit are formed. And a chip provided on the same surface of the flexible substrate.
According to this configuration, as the substrate, a substrate on which terminals and circuits are mounted on one side can be used. Therefore, there is no need to use a high-cost substrate that can be mounted on both sides, and a low-cost projection display device can be provided. Can be provided.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a projection display device of the present embodiment, FIG. 2 is a side configuration diagram of the projection display device, and FIG. 3 is a perspective configuration diagram of a liquid crystal light valve 22 shown in FIGS. is there. In all of the following drawings, the thickness of each component, the ratio of dimensions, and the like are appropriately changed in order to make the drawings easy to see.
[0010]
As shown in FIG. 1, the projection type display device of the present embodiment is a three-panel type including a transmission type liquid crystal light valve 22 to 24 for each of R (red), G (green), and B (blue) different colors. An illumination device 1 which is a projection type color display device and has a light source 2, a fly-eye lens 3, 4, and a polarization conversion device 4d, dichroic mirrors 13, 14, reflection mirrors 15 to 17, lenses 18 to 20, and a liquid crystal light valve 22. 24, a color separation / combination system 30 having a cross dichroic prism 25, and a projection optical system 40 having a projection lens 26.
[0011]
The light source 2 includes a lamp 7 such as a high-pressure mercury lamp or a metal halide lamp, and a reflector 8 that reflects light from the lamp 7. Further, as uniform illumination means for equalizing the illuminance distribution of the light source light L in the liquid crystal light valves 22, 23, and 24, which are illuminated areas, the first fly-eye lens 3 and the second fly-eye lens 4 from the light source 2 side. Are sequentially installed. Each fly-eye lens 3, 4 is composed of a plurality of (for example, 6 × 8) lenses 9, 10 in the present embodiment. The light L emitted from the light source 2 is made uniform in the illuminance distribution by the fly-eye lenses 3 and 4 in the liquid crystal light valves 22 to 24 which are the illuminated areas.
[0012]
The polarization conversion device 4d includes a polarization beam splitter array (PBS array) provided on the uniform illumination means side, and a half-wave plate array for converting the polarization direction of polarized light reflected by the PBS array. The polarization direction of light is aligned in one direction without deteriorating the light intensity.
[0013]
The dichroic mirrors 13 and 14 are formed by laminating a dielectric multilayer film on a glass surface, for example, and selectively reflect light of a predetermined color and transmit light of other wavelengths. That is, the dichroic mirror 13 that reflects blue light and green light transmits the red light LR of the light flux from the light source 2 and reflects the blue light LB and the green light LG. The green light reflecting dichroic mirror 14 transmits the blue light LB and reflects the green light LG among the blue light LB and the green light LG reflected by the dichroic mirror 13.
[0014]
Thus, the red light LR of the light L incident from the illumination device 1 passes through the dichroic mirror 13, is reflected by the reflection mirror 17, and is incident on the red light valve 22. The green light LG is reflected by the dichroic mirror 14 and enters the green light valve 23. After passing through the dichroic mirror 14, the blue light LB passes through a relay system 21 including a relay lens 18, a reflection mirror 15, a relay lens 19, a reflection mirror 16, and a relay lens 20, and is incident on a blue light valve 24. It has become.
[0015]
In the case of the present embodiment, the liquid crystal light valves 22 to 24 are configured as active-matrix transmission-type liquid crystal light valves, and are driven by a drive circuit described later based on signal-processed image signals. I have. The color lights LR, LG, and LB modulated by the light valves 22 to 24 are incident on the cross dichroic prism 25.
The cross dichroic prism 25 has a structure in which right angle prisms are bonded, and a mirror surface that reflects the red light LR and a mirror surface that reflects the blue light LB are formed in a cross shape on the inner surface. Then, after the three color lights LR, LG, LB are combined by these mirror surfaces to form light representing a color image, the light is enlarged and projected on the screen 27 by the projection lens 26.
[0016]
Next, referring to the side view configuration shown in FIG. 2, the color light LR, which is color-separated from the light L emitted from the light source 2, is incident on the liquid crystal light valve 22 and modulated, and is crossed with another color light by the cross dichroic prism 25. It is to be synthesized. In the present embodiment, as shown in FIG. 2, a liquid crystal light valve (light modulator) 22 includes a liquid crystal panel (main body of the light modulator) 35 and a COF substrate connected to one substrate of the liquid crystal panel 35. The COF substrate 32 includes a film substrate (flexible substrate) 33 and a driver IC (integrated circuit chip) 34 mounted on one surface thereof.
[0017]
FIG. 3 is a perspective configuration diagram of the liquid crystal light valve 22 shown in FIG. In the liquid crystal panel 35 according to the present embodiment, a liquid crystal layer is sandwiched between an element substrate 35a and a counter substrate 35b which are arranged to face each other, and a display is performed in a region where the two substrates 35a and 35b overlap in a plane. A pixel portion 39 which is a region is formed. The pixel section 39 has a plurality of pixels arranged in a matrix in plan view. Two driving circuits 37 and 38 are mounted on the peripheral portion of the element substrate 35a, and one driving circuit 37 is electrically connected to a plurality of connecting portions 36 formed in the vicinity thereof. The COF substrate 32 includes a film substrate 33 and a driver IC 34 mounted on one surface side (back surface side in the figure) of the film substrate 33. The driver IC 34 is mounted on an edge of the substrate surface on the side where the driver IC 34 is mounted. A terminal for connecting to the drive circuit 37 is provided, and is connected to a terminal on the element substrate 35 a side to form a connection portion 36. That is, the driver IC 34 and the drive circuit 37 are electrically connected via the connection unit 36. In the case of the embodiment, since the driver IC 34 and the terminals (connection portions 36) of the COF substrate 33 are provided on the same surface side of the film substrate 33, a single-sided COF substrate is used as the COF substrate 33. Can be. Therefore, the cost of the COF substrate 33 can be reduced, and as a result, the cost of the projection display device can be reduced.
[0018]
In the projection type display device of the present embodiment, the liquid crystal light valve 22 as the light modulation device has a configuration in which the driver IC 34 is mounted on the flexible film substrate 33, so that the element substrate 35a of the liquid crystal panel 35 is provided. The area occupied by the circuit on the element substrate 35a can be reduced as compared with the case where all the driving circuits are mounted thereon, and thus the size of the liquid crystal panel 35 can be reduced. Further, among the drive circuits which are required to have higher performance in accordance with higher definition of the liquid crystal panel 35, the driver IC 34 is mainly composed of a circuit which requires higher performance, and the performance of the element may be relatively low. If the circuit is mounted on the element substrate 35a, the high-performance driver IC 34 can be easily applied and the ease of manufacturing the liquid crystal panel 35 can be improved. The liquid crystal light valve 22 with high performance can be manufactured at low cost.
[0019]
Further, when the driving circuits 37 and 38 are external driving circuits, it is necessary to lead an extremely large number of terminals to the element substrate 35a in order to connect the driving circuits and the signal wiring of the pixel portion. In a refined liquid crystal panel, particularly, the pitch of connection terminals becomes narrow, and it becomes difficult to form connection wiring between the external drive circuit and the liquid crystal panel. In contrast, as in the liquid crystal light valve 22 of the present embodiment, the driver IC 34 and the built-in drive circuit 37 cooperate to drive the pixel unit 39, thereby reducing the number of connection units 36. It is also possible to reduce the size, and it is possible to easily cope with miniaturization and high definition of the liquid crystal panel 35.
[0020]
As a specific configuration of the driver IC 34 provided in the liquid crystal light valve 22 shown in FIG. 3 and the drive circuits 37 and 38, for example, a configuration in which functions as shown in FIG. . FIG. 4 is a block diagram showing a configuration example of the liquid crystal light valve according to the present embodiment. As shown in FIG. 4, a liquid crystal panel 35 includes a pixel portion 39 including a plurality of pixels arranged in a matrix. A multiplexer (drive circuit) 37 and a Y driver (drive circuit) 38 are provided in the liquid crystal panel 35. The pixel unit 39 includes an active matrix type pixel including a TFT element as a switching element. Specifically, the pixel unit 39 includes a data line and a scanning line arranged in a stripe shape in a direction intersecting with each other, and the vicinity of the intersection thereof. And a pixel electrode for driving liquid crystal. The data lines are connected to a multiplexer 37, and the scanning lines are connected to a Y driver 38.
Further, a driver IC 34 which is an external drive circuit is connected to the liquid crystal panel 35 via a signal line group 42, and a timing control circuit 41 for controlling them is connected to the liquid crystal panel 35 and the driver IC 34. The pixel section 39 is driven and controlled by a Y driver 38, a multiplexer 37, a driver IC 34, and a timing control circuit 41, which are driving circuits provided around the pixel section 39.
[0021]
The image data DATA, the latch timing signal LP, the start signal ST of the shift register, the data clock signal CLX, and the select signals S1, S2, and S3, which are selection signals, are supplied from the timing control circuit 41 to the driver IC 34 shown in FIG. . The timing control circuit 41 supplies the liquid crystal panel 35 with the start signal DY of the Y driver and the shift signal CLY of the line. The driver IC 34 includes a selector for selecting and outputting one image signal from the image data DATA input from the timing control circuit 41. The selector includes a shift register, a latch circuit, and a driver circuit. Are connected in a permutation.
The driver IC 34 inputs the image data DATA received from the timing control circuit 41 to the latch circuit, and, based on the simultaneously supplied select signals S1, S2, and S3, converts the plurality of image data DATA stored in the latch circuit into One image data corresponding to the select signal is selected and output to the multiplexer 37 via the signal line group 42. On the other hand, the multiplexer 37 outputs the image data DATA received from the driver IC 34 to the data lines of the pixel columns corresponding to the select signals S1, S2, S3. Then, the pixels in each row are switched by a gate signal output from the Y driver 38 to the scanning line in synchronization with the output to the data line, and an image is displayed.
[0022]
According to the above configuration, the plurality of image data DATA input to the selector of the driver IC 34 is made to correspond to one of the three types of select signals, and only the image data DATA corresponding to the select signal is changed while switching these select signals. Since the signal is output to the multiplexer 37, the number of the signal line groups 42 connected to the liquid crystal panel and the drive circuit is reduced to one third as compared with the case where the image data DATA is output to all the signal lines in the pixel column. Since the number of the connection portions 36 shown in FIG. 3 can be reduced, the connection between the COF substrate 33 and the liquid crystal panel 35 can be facilitated. Further, since only the multiplexer 37 mainly composed of a switch circuit having a relatively simple structure is mounted on the liquid crystal panel 35, the area occupied by the drive circuit in the liquid crystal panel 35 can be reduced, and This is extremely advantageous for miniaturization. Further, since the driver IC 34 is provided externally, a driver IC having a higher capability can be easily applied, and it is possible to easily cope with high definition of the pixel portion 39.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a projection display device according to an embodiment of the present invention.
FIG. 2 is a side view of the same.
FIG. 3 is a perspective configuration diagram of the liquid crystal light valve shown in FIG. 2;
FIG. 4 is a block diagram showing a configuration example of a liquid crystal light valve.
[Explanation of symbols]
22-24 liquid crystal light valve (light modulator),
32 COF substrate (substrate), 33 film substrate,
34 driver IC (integrated circuit chip), 35 liquid crystal panel (main unit)

Claims (3)

A light source, a light modulation device that modulates light from the light source, and a projection display device including a projection device that projects light modulated by the light modulation device,
The light modulation device includes a main body that performs the light modulation, a substrate having an integrated circuit chip mounted on a flexible substrate, and is connected to an external control circuit via the substrate. Projection type display device. The projection display device according to claim 1, wherein the integrated circuit chip mounted on the substrate constitutes at least a part of a drive circuit that outputs an image signal to the light modulation device. A connection terminal for connecting the substrate and the light modulation device is formed on an edge of one side of the flexible substrate, and the connection terminal and the integrated circuit chip are on the same surface of the flexible substrate. The projection-type display device according to claim 1, wherein the projection-type display device is provided in a display device.

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