Abstract: A power supply circuit (300) for a display device such as a liquid crystal outputs a boosted supply voltage VDD2 during normal operation, and generates a non-boosted supply voltage VDD2 having a voltage lower than that during the normal display operation by controlling the switches for switching the output within the power supply circuit (300) during a power save mode. The non-boosted supply voltage is supplied to the analog circuits of a driving circuit (100) so that the power consumption at the analog circuits is reduced. By controlling the switch for switching the output within the power supply circuit and the supply of the power supply clock, the circuit can be switched, in the power save mode, to either a mode where a lower supply voltage is generated or to a mode where the power supply is turned off.

Abstract: The display device of this invention, in which the retaining circuit for retaining the image signal is provided for each of the pixel elements, is capable of operating under two operation modes, a normal operation mode and a memory mode. Since the placement of the retaining circuit 110, which requires relatively large area, is confined to the area for the pixel element electrode 17 not in between the neighboring pixel element electrodes 17, the required area for one pixel element is minimized, resulting in the size reduction of the liquid crystal display device. By placing at least a portion of the retaining circuit in the area of the pixel element electrode 17 of the neighboring pixel element, the detour of the wiring can be omitted, resulting in the efficient use of the space. By this, the area required for the retaining circuit is minimized, directly resulting in the reduction of the size of the liquid crystal display device.

Abstract: Graphics are drawn with an input pen, which is provided with an optical sensor at its tip, on a display surface of an EL display. At this time, the EL display is caused to emit light in dot sequence, and the position of the input pen is detected as coordiante information on the basis of timing of light emission of the EL display and timing of light emission detection of the input pen.

Abstract: A driving circuit of a display device such as a liquid crystal generates power supply clocks (1 and 2) based on a system clock during the normal display operation which is not a power save mode. The generated power supply clocks are supplied, directly or after inversion, to the switches (SW1 through SW4 (and SW5 through SW8)) in a charge pump type power supply circuit (300) for switching the connection of capacitors (C1 and C2 (and C11 and C12)) in the power supply circuit (300). In this manner, supply voltages VDD2 and VDD3 which function as the driving power supply for a driving circuit (100) and a display panel (200) can be obtained at the power supply circuit (300) by boosting the input voltage Vin.

Abstract: A liquid crystal display apparatus includes a liquid crystal display panel having preset display characteristics, such as image brightness and contrast. A luminescent unit is optically connected with the display panel and provides light to the display panel in order to form an image on the display panel. The luminescent unit includes a light collector which collects ambient light and a light source, for generating light when the amount of ambient light is insufficient to generate a clear image. A control circuit is electrically connected to the display panel and automatically varies the preset display characteristics in accordance with the amount of ambient light collected by the light collector.

Abstract: External light is introduced by a light-introducing portion to be used as a light source for a backlight, so that the power consumption of the backlight of a liquid crystal display device can be suppressed. At the same time, the brightness of the screen of the liquid crystal display device can be increased to enhance the visibility in outdoors. Therefore, the portability of a mobile information terminal can be improved. Furthermore, the light-introducing portion covers an end portion of the main unit opposed to an axis, whereby the main unit is protected so that the life period of the mobile information terminal can be prolonged. The variety of the design of the mobile information terminal can be increased by using the transparency of the light-introducing portion.

Abstract: External light is introduced by a light-introducing portion to be used as a light source for a backlight, so that the power consumption of the backlight of a liquid crystal display device can be suppressed. At the same time, the brightness of the screen of the liquid crystal display device can be increased to enhance the visibility in outdoors. Therefore, the portability of a mobile information terminal can be improved. Furthermore, the light-introducing portion covers an end portion of the main unit opposed to an axis, whereby the main unit is protected so that the life period of the mobile information terminal can be prolonged. The variety of the design of the mobile information terminal can be increased by using the transparency of the light-introducing portion.

Abstract: A liquid crystal display apparatus includes a liquid crystal display panel having preset display characteristics, such as image brightness and contrast. A luminescent unit is optically connected with the display panel and provides light to the display panel in order to form an image on the display panel. The luminescent unit includes a light collector which collects ambient light and a light source, for generating light when the amount of ambient light is insufficient to generate a clear image. A control circuit is electrically connected to the display panel and automatically varies the preset display characteristics in accordance with the amount of ambient light collected by the light collector.

Abstract: An improved liquid crystal display device of the type having a liquid crystal display panel, a light guide plate below a surface of the display panel and located between a reflecting portion and a diffusing portion, and a light collecting lens located at one end of the light guide plate for collecting and transmitting light to the light guide plate for providing backlight to the display panel. The display device includes a light transmitter located between the light collecting lens and the light guide plate. The light transmitter optically connects the light collecting lens and the light guide plate and separates the light collecting lens from the display panel by a predetermined difference. The light transmitter allows light to be more evenly distributed or reflected onto the display panel so that images displayed on the panel have a more uniform brightness.

Abstract: The display device of this invention, in which the retaining circuit for retaining the image signal is provided for each of the pixel elements, is capable of operating under two operation modes, a normal operation mode and a memory mode. Since the placement of the retaining circuit 110, which requires relatively large area, is confined to the area for the pixel element electrode 17 not in between the neighboring pixel element electrodes 17, the required area for one pixel element is minimized, resulting in the size reduction of the liquid crystal display device. By placing at least a portion of the retaining circuit in the area of the pixel element electrode 17 of the neighboring pixel element, the detour of the wiring can be omitted, resulting in the efficient use of the space. By this, the area required for the retaining circuit is minimized, directly resulting in the reduction of the size of the liquid crystal display device.

Abstract: In the driving of a liquid crystal display panel with pixels in a matrix comprising n rows and m columns, when a partial display instruction is issued, respective rows in a display area (202) of s rows and m columns within the matrix are sequentially selected for one frame. Then, predetermined partial display data is written into the selected rows. Predetermined background data such as white display data is written into the background area (204) other than the partial display area (202). In the background area 204, either k rows and m columns or pixels of (the leading row ((s+1)-th row) of the background area, next to the final row in the partial display area) are selected during one frame for writing of the background display data, k rows and m columns are sequentially shifted each frame.

Abstract: A signal driving circuit for an active matrix type display device having display pixels arranged in a matrix, comprises a signal waveform correcting circuit receiving an input pixel signal for generating a corrected output pixel signal to the display device, said signal waveform correcting circuit including a delay circuit for generating a delay signal, a difference calculating circuit for calculating a difference signal between the input pixel signal and the delay signal, and a correction circuit for generating the corrected output pixel signal based upon the difference signal and the input pixel signal, wherein a portion of the waveform amplitude of the corrected output pixel signal is formed by adjusting a corresponding portion of the waveform amplitude of the input pixel signal based upon the difference signal.

Abstract: A driving circuit of a display device such as a liquid crystal generates power supply clocks (1 and 2) based on a system clock during the normal display operation which is not a power save mode. The generated power supply clocks are supplied, directly or after inversion, to the switches (SW1 through SW4 (and SW5 through SW8)) in a charge pump type power supply circuit (300) for switching the connection of capacitors (C1 and C2 (and C11 and C12)) in the power supply circuit (300). In this manner, supply voltages VDD2 and VDD3 which function as the driving power supply for a driving circuit (100) and a display panel (200) can be obtained at the power supply circuit (300) by boosting the input voltage Vin.

Abstract: A power supply circuit (300) for a display device such as a liquid crystal outputs a boosted supply voltage VDD2 during normal operation, and generates a non-boosted supply voltage VDD2 having a voltage lower than that during the normal display operation by controlling the switches for switching the output within the power supply circuit (300) during a power save mode. The non-boosted supply voltage is supplied to the analog circuits of a driving circuit (100) so that the power consumption at the analog circuits is reduced. By controlling the switch for switching the output within the power supply circuit and the supply of the power supply clock, the circuit can be switched, in the power save mode, to either a mode where a lower supply voltage is generated or to a mode where the power supply is turned off.

Abstract: In the &ggr; correction circuit, a crossover point arithmetic processing unit performs arithmetic processing for each region on crossover points y in the output data direction of a &ggr; correction crossover line based on a plurality of slope data A respectively specified for each of a plurality of regions and crossover point positions X in the input data direction set in advance.

Abstract: A backlight for a liquid crystal display includes a light guide plate located adjacent to a liquid crystal display panel. A light collector is located at one end of the light guide plate and has an exposed surface for receiving ambient light. The light collector has a reflector secured inside it. The received ambient light is reflected by the reflector along the light guide plate. The reflector may include three arcuate shaped reflecting elements. The light guide plate has a reflective surface which reflects the light toward the liquid crystal display panel.

Abstract: There is proposed is a method of controlling a flat panel display apparatus for multi-gradation display in which a data determination portion and a subfield control portion are provided. Based on a most significant bit or an upper bit of original image data, it is determined in which one of two or more divided gradation groups the original image data is included, to select a combination of subfields in accordance with a gradation-brightness characteristic of the belonging gradation group. Using a complementary relationship with human visibility, a difference in brightness between the gradations in a low-order brightness region is reduced, and a difference in brightness between the gradations in a high-order brightness region is enlarged. Therefore, a density of brightness is uniformly recognized visually over all the brightness regions, and a good quality of display can be obtained.

Abstract: An image processing apparatus detects, in step 1, whether or not differences between currently supplied image data and image data of a previous pixel are more than a predetermined value m, and identifies a border of a computer-created image or a natural image, where a brightness level differs from the remaining area of the image, when the differences are more than the predetermined value m. Conversely, when the differences are less than the predetermined value m, the image processing apparatus checks, in step 2, whether image data at a pixel before and a pixel two before the current pixel are identical with respect to the color components constituting the color image. When the differences are not all zero, it is checked whether or not the image data at a pixel before the current pixel and the image data at the current pixel are all zero. When the image data are not identical, the color image is identified as being a natural image.

Abstract: A liquid crystal display (LCD) includes liquid crystal display panel located within a housing. A backlight source is detachably connected to the housing for providing light to the display panel. When the backlight source is removed from the housing, outside light, such as ambient light, provides light to the display panel. The LCD includes a light collecting lens which transmits light to the display panel and which is either covered by the backlight source or exposed to an external light source when the backlight source is detached from the housing. When the backlight source is detached, the LCD has a small size and light weight, making it convenient for carrying and using outdoors. The LCD also consumes less power when the backlight source is detached.

Abstract: There is provided an image information process apparatus to be applied to a display for displaying bit image display data for each pixel, for enabling the display to display continuous tones in an error diffusion manner based on P bit image data, P being larger than L. This apparatus includes a plurality of adding circuits to which a plurality of P bit image data are concurrently supplied. A predetermined lower bit of an added result at respective adding circuits is used as error data supplied to the next adjacent adding circuit. An error data holding circuit holds a predetermined lower bit of an output from an adding circuit corresponding to the last column pixel in image data supplied. It then supplies the lower bit held to an adding circuit corresponding to the top front column pixel of the image data supplied.