Abstract: At least one exemplary embodiment is directed to an image display apparatus, which can include multiple color combining elements, multiple light modulating elements, and a projection optical system, operatively connected to reduce the effects of ghost light.

Abstract: A display device is constructed with conductive fibers which are coated with a display medium and are woven together with transparent conductive fibers. The conductive fibers coated with a display medium serve as warps and the transparent conductive fibers serve as wefts. The display device is not provided with an external electrode and is therefore flexible like plain cloth.

Abstract: A circuit for automatically biasing a common electrode of a liquid crystal on silicon imager comprising an imager with a common electrode and a plurality of cells. A varying voltage signal is provided to the plurality of cells. A low pass filter is coupled between the varying voltage signal and a common junction coupled to the common electrode such that a bias voltage is formed at the common electrode having a value that approximates an average of the varying voltage signal.

Abstract: In a light sensing element having simplified structure, an array substrate having the light sensing element and an LCD apparatus having the light sensing element, the light sensing element includes a first electrode, a control electrode and a second electrode. An alternating bias voltage is applied to the first electrode. An off voltage is applied to the control electrode. The second electrode outputs a light-induced leakage current based on an externally provided light and the bias voltage. Therefore, the array substrate includes one light sensing switching element corresponding to one pixel so that structure of the array substrate is simplified and opening ratio is increased.

Abstract: This invention provides a method and an apparatus for saving power dissipation during the testing and evaluation of liquid crystal display LCD panels. In addition, this invention provides a method and apparatus of the changing of the order of backplane and segment addressing to reduce the power consumed by LCD panels. The method includes the step of interlacing the access of common or backplane addresses to an LCD. The LCD power saving method also includes the interlacing the access of the RAM data driving the LCD segment drivers. The segment address signals are developed from data read out of a random access memory, RAM. The segment address signals are activated such that alternating LCD panel locations are written with ones and zeros in a checkerboard pattern so as to stress the LCD panel in the worst case. This method provides for the saving of power dissipation during testing and evaluation by reducing the amount of segment switching from once every backplane cycle to once every frame.

Abstract: An system is disclosed for driving a liquid crystal display for automatically adjusting a level of a common voltage at the point that a positive polarity gray scale level voltage and a negative polarity gray scale level voltage are supplied to a liquid crystal display panel. A plurality of gate lines and a plurality of data lines are provided at a liquid crystal display panel. A gate driver supplies a gate pulse to the plurality of gate lines. A data driver supplies a positive polarity gray scale level voltage and a negative polarity gray scale level voltage to the plurality of data lines. A controller controls a common voltage level supplied to the liquid crystal display panel in accordance with a supply point of a gate pulse.

Abstract: A display device includes a side I/O module sandwiched between a front frame and a rear cover to form a casing having a lateral side. The I/O module includes an L-shaped connector including a back plate fastened securely to the rear cover, and a side plate extending perpendicularly from the back plate and fastened the front frame so to prevent removal of the rear cover from the front frame in such a manner that the side plate is flush with the lateral side of the casing. A terminal substrate is mounted on the back plate opposite to the rear cover, and has a plurality of parallelly arranged terminal-receiving ports extending into the opening in the side plate so as to expose the ports exteriorly of the outer casing to facilitate insertion of terminals therein.

Abstract: In an image display device, how R, G, and B light is emitted to display an image on a display panel is measured with a sensor, and, according to the measurement value obtained from the sensor, the power with which to drive a light source that supplies light needed for the display operation of the display panel is varied so that the brightness or chromaticity of the display panel is corrected.

Abstract: A display apparatus having: a panel displaying a picture; a panel driver enabling the panel to display the picture; a scaler transferring an input image signal to the panel driver; a key input part generating a color change execution signal for the input image signal by manipulation of a user; and a controller modifying a voltage level value of the input image signal and transferring a modified input image signal to the scaler, if the input image signal transferred to the scaler is identical over a predetermined period of time, after receiving the color change execution signal from the key input part. As described, an embodiment of the present invention provides the display apparatus and the control method thereof providing the user with the information displayed on the screen and preventing screen modulation when identical display data are displayed on the screen over the predetermined period of the time.

Abstract: An optical address type spatial light modulator has a plurality of optical address type light modulation layers stacked on each other, each having a liquid crystal layer for reflecting visible light in a specific wavelength band or a liquid crystal layer for absorbing visible light in a specific wavelength band and coloring and a photoconductive layer for absorbing the visible light in the specific wavelength band and changing the resistance value in response to the light intensity of the visible light absorbed, the liquid crystal layer and the photoconductive layer being stacked on each other between electrodes.

Abstract: A novel personal electronic device includes a first (embedded) and second (non-embedded) processors including associated operating systems and functions. In one aspect, the first processor performs relatively limited functions, while the second processor performs relatively broader functions under control of the first processor. Often the second processor requires more power than the first processor and is selectively operated by the first processor to minimize overall power consumption. Protocols for functions to be performed by the second processor may be provided directly to the second processor and processed by the second processor. In another aspect, a display controller is designed to interface with both processors. In another aspect, the operating systems work with one another. In another aspect, the first processor employs a thermal control program. Advantages of the invention include a broad array of functions performed by a relatively small personal electronics device.

Abstract: A liquid crystal display apparatus including: a liquid crystal display element having a liquid crystal layer between a couple of substrates; a backlight apparatus arranged at one side of the couple of substrates; a polarizer arranged between the liquid crystal display element and the backlight apparatus; a luminous intensity distribution control element arranged at the other side of the couple of substrates; an analyzer arranged between the liquid crystal display element and the luminous intensity distribution control element, wherein the luminous intensity distribution control element comprises a transparent base member, a plural lenses arranged on the transparent base member, and a light absorbing layer having small opening portions substantially at focal positions of an individual lens of the plural lenses, and the transparent base member is constituted of a transparent body substantially optically isotropic or a transparent body having uniaxial optical anisotropy.

Abstract: An interpolation processor interpolates reference compensation data stored in a ROM according to the level, generates compensation data corresponding to levels available to image data for each pair of reference coordinates, and stores the compensation data in a compensation table. An address generator specifies storage regions for compensation data corresponding to four pairs of reference coordinates positioned near coordinates of the image data among the compensation data stored in the compensation table. An arithmetic unit interpolates the compensation data read from the compensation table according to the coordinates and generates compensation data. In writing positive polarity, the compensation data is added to the image data. In writing negative polarity, compensation is not performed. It is thereby possible to reduce, minimize or prevent flickering generated in the entire region of a display screen.

Abstract: Disclosed herein is a liquid crystal display apparatus comprising: a liquid crystal display element composed of a liquid crystal layer and having a plurality of pixels arranged in a matrix pattern; and a driver for dividing one frame into plural fields and interlace-scanning the plurality of fields. In one embodiment, the driver is so structured to drive the respective fields composing one frame so that a scanning order of the fields is discontinued at least once. In another embodiment, the driver is so structured to drive scanning lines by means of a driving waveform having a reset period for resetting a state of liquid crystals, a selection period for selecting a final display state of the liquid crystals, and a maintaining period for establishing the state selected at the selection period, and starts scanning of next field based on reset period end timing of one scanning line of the previous field.

Abstract: Apparatus for driving a cholesteric liquid crystal display wherein the display includes cholesteric liquid crystals having a first planar reflective state and a second transparent focal conic state, which is respectively responsive to different applied fields; an addressing structure having rows and columns of conductors arranged so that when a column and a row overlap, they define a selectable pixel or segment to be viewable or non-viewable; the apparatus being adapted to switch between a first and a second fixed voltage.

Abstract: A semiconductor device carries out a test utilizing contact with a probe needle without being affected by narrowing of the pitch at which output pads are arranged. The device is equipped with test circuits provided between a plurality of output buffers via which signals are output and output pads corresponding thereto. The test circuit includes output switches caused to sequentially make connections by a controller in test and interpad switches involved in making connections of the output pads with a test pad by the controller in test. In test, probe needles are brought into contact with the test pad. The output pads are not used in test, and can be arranged at a narrowed pitch. Thus, the chip area can be reduced and are therefore so that the pitch for the output pads can be narrowed and the chip area can be decreased.

Abstract: Disclosed is an LCD driver integrated circuit package and a chip on glass type LCD device using the package. The LCD driver integrated circuit package includes a mold that has signal output bumps and signal input bumps formed thereon, wherein the signal output bumps and the signal input bumps have different surface areas that contact the mold and an adjacent conductive film. Due to the different contact surface areas, different amounts of pressure are applied to different parts on the conductive film when a force is applied to the mold. One or more bump pressure control patterns are formed on the mold compensate for the difference in pressure caused by this difference between the total contact areas. Accordingly, the LCD driver integrated circuit package can be mounted on a chip on glass type LCD panel without causing device failure.

Abstract: Power-efficient, pulsed driving of capacitive loads to controllable voltage levels, with particular applicability to LCDs. Energy stored in a portion of the capacitive load is recovered during a recovery phase. Time-varying signals are used to drive the load and to recover the stored energy, thus minimizing power losses, using processes named adiabatic charging and adiabatic discharging.

Abstract: A device for enhancing contrast for a liquid crystal display (LCD) projection system is provided. The contrast enhancing device includes an image driver supplying an image signal, a LCD panel for converting the input image signal into an optical image signal, and a contrast control portion positioned on the same optical axis as that of the LCD panel, for controlling an amount of scanned light according to the brightness of a corresponding image. Accordingly, the projection system adopting an image display device as a liquid crystal device provides a remarkably enhanced contrast enhancement effect. In particular, as the brightness of the total image is brighter, the contrast enhancement effect becomes larger.

Abstract: A liquid crystal display includes a first TFT for controlling a supply of a display signal to a pixel electrode, a second TFT connected to the first TFT, and a third TFT connected to a data line. The third TFT controls the supply of a display signal to the pixel electrode. The second and third TFTs are connected to a gate line Gn+1, and the first TFT is connected to a gate line Gn+2.

Abstract: Liquid crystal display with conductive segments for representing symbols which also has at least one inverse segment that fills at least in part the display area that is not covered by the remaining segments. This liquid crystal display allows a simple, visual detection of faulty segments. For this purpose a check is carried out in which all segments and all existing inverse segments are activated which results in a homogenous image when the display is completely functional or the faulty segments are inversely displayed in relation to the remaining display surfaces.

Abstract: The optical indicator unit of a program-controlled household appliance includes one or more indicator elements for the display of information in plain text. Each indicator element includes a matrix with 5×8 pixels for the display of a character. Each indicator element is assigned a functional element/actuator belonging to the household appliance. The element/actuator and also at least one operating state of the element/actuator is represented in the indicator element by an initial letter or a symbol. Depending on a size of the display, a plurality of actuators can be indicated at the same time. The invention can be applied particularly well in testing and in servicing.

Abstract: A liquid crystal display apparatus for displaying an image on a liquid crystal cell through a liquid crystal driver driven by a predetermined number of bits by inputting image data in which one pixel is represented with a plurality of sub-pixels. The liquid crystal display apparatus includes: memory for storing information about an offset for converting gray level coordinates of a gamma characteristic spaced evenly according to the number of bits into gray level coordinates spaced unevenly; a gray level adjustment portion for performing a calculation on particular input sub-pixel data based on information about the offset stored in the memory; and a pseudo-gray-level-expansion portion for applying pseudo gray level expansion to the sub-pixel data calculated by the gray level adjustment portion. The sub-pixel data to which the pseudo gray level expansion is applied by the pseudo-gray-level-expansion portion is supplied to the liquid crystal driver to display the image on the liquid crystal cell.

Abstract: The invention relates to a display device which includes a driver circuit and a liquid crystal display with a plurality of rows R and columns C. The invention also relates to a driver circuit for driving a display. In order to reduce the power consumption of display devices, displays are operated in the partial display mode. According to the MRA (Multiple Row Addressing) technique a plurality of rows p is driven simultaneously. The number of rows p to be simultaneously driven, however, differs for displays of different size. When a display is operated in the partial display mode, therefore, for an optimum optical performance it is necessary that the value p of the rows to be simultaneously driven is other than this number in full size operation. In order to drive the rows R and columns C, at least p+1 voltages are required when F=GMAX.

Abstract: In a display device, an active element (A) captures data of a signal line into a memory element while the active element (A) is selected by a selection line. The active element applies a reference voltage to an organic EL element according to storage contents of the memory element, thereby performing a storage holding operation for each pixel while preventing rewriting of the same data so as to save power. In order to realize multi-gray-level display, the display device reduces the number of wires and power consumption.

Abstract: In an electro-optical device including a scanning line driving circuit, the scanning line driving circuit includes a transfer direction control circuit for controlling the direction of transfer of a start pulse, a shift register for shifting the start pulse, supplied by the transfer direction control circuit, in response to a clock signal, and an output selection circuit for selecting the output signal of the shift register in accordance with a first enable signal and a second enable signal. A decimation process and a stretching process are performed by controlling the first enable signal and the second enable signal in accordance with the video line count of an input video signal.

Abstract: A liquid crystal display includes an electro-luminescence portion which has electro-luminescence elements and a liquid crystal portion which has liquid crystal layer, scanning electrodes and signal electrodes and controls the transmittance of light emitted by the electro-luminescence elements. First, scanning pulses are applied in sequence to the scanning electrodes. Next, a gradation signal are applied associated with image data to the signal electrodes. Then, the electro-luminescence portion is allowed to emit light of a plurality of colors at the same time in pixels after transmissivity of the liquid crystal layers in the pixels reaches a predetermined value. The pixels are located at the intersections between a scanning electrode to which the scanning pulse is applied and the signal electrodes to which the gradation signal is applied.

Abstract: A method of making display having a display area capable of displaying a plurality of characters in a background, the characters including a plurality of segments, includes the steps of: providing a substrate; forming a first patterned conductor layer on the substrate having electrically separate areas defining character regions, the first patterned conductor being substantially coextensive with the display area; depositing a layer of light modulating material over the first patterned conductor layer; forming a second patterned conductor layer over the layer of light modulating material and having electrically separate areas defining the segments of the characters and the background, the second patterned conductor being substantially coextensive with the display area; depositing a dielectric layer over the second patterned conductor layer, the dielectric layer defining holes over each segment and the background area of the second patterned conductor layer; and forming a third patterned conductor layer located

Abstract: A portable electronic device (10) has an integrated display and camera. The portable electronic device (10) includes a printed circuit board (60), a display (30) having one or more display layers, and an integrated camera coupled between the one or more display layers and the printed circuit board (60), wherein the one or more display layers are constructed such that a light stream (105) flows through to the integrated camera.

Abstract: A display element having a plurality of pixel portions arranged two-dimensionally with a predetermined pixel pitch and a microlens array including a plurality of microlenses arranged two-dimensionally corresponding to the plurality of pixel portions on an incident side or an emission side of light with respect to the pixel portions, wherein, in the microlens array, each microlens has a lens surface of a hyperboloid of revolution, and a lens pitch of the plurality of microlenses is set to a pitch smaller than the lens pitch able to substantially equivalently maintain a converging efficiency of a lens of the hyperboloid of revolution and a lens of an ellipsoid of revolution with respect to the incident light and able to maintain a converging efficiency higher than the converging efficiency of the lens of the ellipsoid of revolution or wherein, in the microlens array, each microlens has a lens surface of a hyperboloid of revolution, and a lens pitch is 20 &mgr;m or less; a display device; and a microlens array.

Abstract: A reflective spatial light modulator (SLM) includes a first substrate, a second substrate and an electro-optic material positioned between the first and second substrates. The first substrate includes a reflective ground layer that acts as a continuous first electrode and the second substrate includes a pixel layer having a plurality of pixel elements formed in a pattern. The pixel elements are formed of a transparent conductive material and are separated by inter-pixel regions formed of a non-conductive material. A transmissivity of the electro-optic material in a vicinity of each of the plurality of pixel elements is controlled by a potential difference applied between the first electrode and a respective one of the pixel elements.

Abstract: A liquid crystal display has a signal transmission film and a single integrated PCB for processing a gate driving signal and data driving signal. The signal transmission film includes a base substrate, a gate driver IC formed on said base substrate, an input pattern formed on said base substrate that applies gate driving signals input from an external device to the gate driver IC, a first output pattern formed on said base substrate that outputs a first gate driving signal processed in said gate driver IC, and a second output pattern formed on said base substrate, that outputs a second gate driving signal bypassing the gate driver IC among the gate driving signals.

Abstract: A method of making a programmable shelf tag, including the steps of supplying a display element having a single flexible transparent; mounting the display element substrate side down in a window formed in a web of adhesive backed print medium having a die cut area around the display element to form an adhesive label that includes the display element; printing static information on the label of the print medium; supplying a support for mounting the adhesive; and attaching the adhesive label to the support.

Abstract: A method for evaluating the image quality of a color liquid crystal display (LCD), and a system for measuring the modulation transfer function (MTF) for use in the evaluation of the image quality. The image quality evaluation method involves measuring the MTF at a predetermined position on the screen of an LCD, and the image quality is evaluated using the measured MTF. The MTF measuring system, which includes a linear charge coupled device (CCD) camera equipped with a V(&lgr;) filter, is able to accurately measure the image quality of a color LCD by setting the measuring conditions through computer simulation. In addition, the resolution and signal-to-noise characteristics of an image displayed on the screen can be evaluated based on the measured MTF. Also, the problem of truncation of the line spread function (LSF) can be solved by fixing the scanning width. The spectral response characteristics of detectors can be made like those of the human eye using the V(&lgr;) filter.

Abstract: The present invention relates to a driving circuit used suitably for driving a capacitive load such as liquid crystal panel. The driving circuit of the present invention comprises a differential amplifying circuit, an output circuit and current control circuit. The output circuit is driven by an output signal of the differential amplifying circuit. A increased current signal is injected to the current control circuit for applying a positive feedback to increase an operating current of the differential amplifying circuit. A negative feedback for decreasing the increased current signal thus injected is also applied to the aforesaid current control circuit.

Abstract: This invention provides a resolution control system for a display device, which may have a lighted display and control circuitry. The lighted display may be backlit, frontlit, or emissive. The resolution control system may have two or more digital-to-analog converters, which may be provided by digital-to-analog converter (DAC) circuitry in the control circuitry. The DACs convert data values into an output voltage for controlling an operating parameter, which may be brightness, contrast, and the like. The DACs have a cascade arrangement where the output voltage of one DAC is the input voltage of another DAC.

Abstract: A liquid crystal display panel (10) in a watchcase (41) displays time information and/or calendar information. In the liquid crystal display panel (10), a liquid crystal layer (3) is disposed between an upper substrate (1) and a lower substrate (2). On the upper substrate (1) are formed segment electrodes (5g) and an auxiliary electrode (11) that surrounds the segment electrodes with gaps (G1), and the segment and auxiliary electrodes are composed of the same transparent conductive film. An opposite electrode (6) is formed over the entire display area of the lower substrate (2). The overlaps between the opposite electrode (6) and the segment electrodes (5g) form pixel areas (32), while the overlap between the opposite electrode (6) and the auxiliary electrode (11) forms a background area (33).

Abstract: A liquid crystal display device capable of displaying in multiple colors, and a method for driving the liquid crystal display device using a typical monochrome liquid crystal driving IC. A display portion of a birefringence color liquid crystal display device has a usual letter display portion (41) for displaying letters in a single color and a mark display portion (42) for displaying a variety of colors. A liquid crystal cell is driven by supplying scanning signals to scanning electrodes for the letter display portion (41) and data signals to scanning electrodes for the mark display portion (42).

Abstract: A camera display system displays information via a matrix display element mounted within a housing that is positioned relative to at least eye of a user. The display is connected to a video or image sensor such that the user can view information or images shown on the display. The display can be mounted to a housing so that the user can move the display in and out of the user's field of view.

Abstract: Apparatus for driving a cholesteric liquid crystal display wherein the display includes cholesteric liquid crystals having a first planar reflective state and a second transparent focal conic state, which is respectively responsive to different applied fields; an addressing structure having rows and columns of conductors arranged so that when a column and a row overlap, they define a selectable pixel or segment to be viewable or non-viewable; the apparatus being adapted to switch between a first and a second fixed voltage.

Abstract: A road image display device for displaying an image of a road whereon a vehicle is travelling on a display screen by scrolling the road image at a specified speed as one would feel driving a vehicle thereon viewing the image from a fixed viewing point, which display device is provided with an input control section for inputting road design data concerning a straight line area, a clothoid curve (relaxed-curvature curve) area and a circular-arc area for a travelling road distance, and an electronic control unit for generating a road image representing a straight-line area, clothoid curve area and a circular-arc area according to the input road design data and which can easily generate any desired road image according to a free road design and more particularly can represent an image of a curved road portion by a curve having a relaxed curvature for joining a straight-line with a circle of a constant curvature.

Abstract: Disclosed is a lighting system simulating sunrise and sunset, which can control a desired luminous intensity and color temperature to be turned on or off on a wanted time in an easier manner by employing a remote controller for transferring a remote signal, a controller for controlling the on and off condition of the luminous intensity and color temperature of a stabilizer based on the remote signal transferred from the remote controller and a self stacked signal, and a liquid crystal display device for displaying the luminous intensity and the color temperature on a graphic screen to easily identify the result of the aforementioned control.

Abstract: A method of recording rewritable time related information on a label, includes the steps of providing an electrically rewritable label associated with an article which includes a plurality of rewritable segments, each such segment having a layer including a material which is effective in at least first and second optical states so that the time related information can be written, rewritten and viewed, wherein such time related information relates to usage or potential usage of the article or a device associated with the article and such time related information can be electrically changed by providing appropriate electrical fields to the material, and electrically addressing selected segments to write or rewrite appropriate time related information.

Abstract: A method and apparatus for driving a plasma display panel in which a reset discharge is selectively performed with regard to the distribution of wall charges in discharge cells are provided. The method includes applying a reset signal for preventing a reset discharge from occurring in cells having conditions under which an address discharge can occur during the address period and allowing a reset discharge occur in cells which do not have the above conditions. Accordingly, an unnecessary discharge can be suppressed, thereby making a dark portion darker. Therefore, contrast can be greatly improved, and a time for a reset period can be reduced.

Abstract: A display apparatus includes a display panel and a logic switch unit. The display panel has a plurality of common electrodes and a plurality of segment electrode arranged in a direction orthogonal to the plurality of common electrodes. Display cells are formed at intersections of the plurality of common electrodes and the plurality of segment electrodes. The logic switch unit short-circuits selected at least one of the plurality of common electrodes corresponding to a display cell group and selected ones of the plurality of segment electrodes corresponding to the display cell group in response to a common-segment short-circuit timing signal. The display cell group includes selected ones of the display cells.

Abstract: A plurality of sealing methods may be used either alone or in combination with each other to seal an electronic display structure. The display module includes a first substrate having a plurality of column electrodes. Each of a plurality of portions of a display material are coupled to one of the plurality of column electrodes and to one of a plurality of row electrodes. A pixel seal may be formed over the display material to encapsulate the display material. An area seal may be formed upon the first substrate to encapsulates the row electrodes, the column electrodes, and the portions of display material. A bead seal may be formed around the perimeter of the first substrate to couple it to a second substrate while sealing the internal display material. An edge seal may be formed by a banded structure spanning from the first substrate to the second substrate and extending around the perimeter of the substrates.

Abstract: A device including a microcontroller fabricated on a semiconductor chip is used to control an LCD display of an external system intended to be controlled by the microcontroller. The microcontroller enters a sleep state in which it operates in a battery power conservation mode during periods of time when functional activity of the microcontroller is reduced. The microcontroller awakens from the sleep state for resumption of activity when such a period ends. Timing to the LCD is decoupled from the microcontroller's own internal clock when the independent internal on-chip clock, which may be an RC oscillator, is selected by the user of the device. This allows the chip to continue to drive the LCD display even though the microcontroller's internal clock has stopped during the sleep.

Abstract: A display for presenting selected images to a viewer is disclosed, including a transparent substrate, a transparent, electrically conductive coating formed over the transparent substrate, a light modulating layer formed over the transparent, electrically conductive layer and a photosensitive layer formed over the light modulating layer which is adapted to be exposed and developed to provide viewable and conductive images.

Abstract: A color liquid crystal display device has a liquid crystal layer of nematic liquid crystal having positive dielectric anisotropy and including a chiral material, which is interposed between two substrates disposed substantially in parallel, each provided with a transparent electrode and an aligning layer. The twist angle of the liquid crystal layer of liquid crystal molecules determined by the aligning layer of each of the substrates is 160°-300°. A pair of polarizing plates disposed outside the liquid crystal layer. A driving circuit applies a driving voltage across the transparent electrodes. A birefringent plate is disposed between the liquid crystal layer and an upper polarizing plates and a product &Dgr;n1·d1 of a refractive index anisotropy &Dgr;n1 of the liquid crystal in the liquid crystal layer and a thickness d1 of the liquid crystal layer is 1.2 &mgr;m-2.5 &mgr;m.

Abstract: A tool for selectively marking a surface in specific desired increments for use in a variety of mechanical arts. The tool has a ruled face and indicates selected increments by illuminating light emitting devices corresponding to the locations to be marked.