Patents by Inventor Dwight G. Baldwin

Dwight G. Baldwin has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10578884
    Abstract: An optical component array and method of making an optical component array includes a plurality of optical components useful for projection devices or other optical devices.
    Type: Grant
    Filed: November 14, 2017
    Date of Patent: March 3, 2020
    Assignee: 3M INNOVATIVE PROPERTIES COMPANY
    Inventors: Joseph C. Carls, James M. Nelson, Charles N. DeVore, Dwight G. Baldwin
  • Publication number: 20180081191
    Abstract: The present disclosure provides an optical component array and method of making an optical component array that can include a plurality of optical components useful for projection devices or other optical devices. The optical component array can be fabricated such that individual optical components having several elements can be assembled in a massively parallel manner and then singulated as individual optical components, and can result in a large reduction in manufacturing cost.
    Type: Application
    Filed: November 14, 2017
    Publication date: March 22, 2018
    Inventors: Joseph C. Carls, James M. Nelson, Charles N. DeVore, Dwight G. Baldwin
  • Patent number: 9841605
    Abstract: The present disclosure provides an optical component array and method of making an optical component array that can include a plurality of optical components useful for projection devices or other optical devices. The optical component array can be fabricated such that individual optical components having several elements can be assembled in a massively parallel manner and then singulated as individual optical components, and can result in a large reduction in manufacturing cost.
    Type: Grant
    Filed: June 20, 2013
    Date of Patent: December 12, 2017
    Assignee: 3M Innovative Properties Company
    Inventors: Joseph C. Carls, James M. Nelson, Charles N. DeVore, Dwight G. Baldwin
  • Publication number: 20150136950
    Abstract: The present disclosure describes optical elements and optical devices that use the optical elements to allow the output of two imagers to be combined onto a single optical axis. Each of the two imagers can be based on alternate polarization directions, and the disclosed embodiments can enable high contrast 3D projectors without requiring either time or polarization sequencing. The present disclosure further describes projection systems that include the optical devices.
    Type: Application
    Filed: April 11, 2013
    Publication date: May 21, 2015
    Applicant: 3M INNOVATIVE PROPERTIES COMPANY
    Inventors: Joseph C. Carls, Craig R. Schardt, Duane E. Preiss, Dwight G. Baldwin
  • Publication number: 20150098128
    Abstract: The present disclosure provides an optical component array and method of making an optical component array that can include a plurality of optical components useful for projection devices or other optical devices. The optical component array can be fabricated such that individual optical components having several elements can be assembled in a massively parallel manner and then singulated as individual optical components, and can result in a large reduction in manufacturing cost.
    Type: Application
    Filed: June 20, 2013
    Publication date: April 9, 2015
    Applicant: 3M INNOVATIVE PROPERTIES COMPANY
    Inventors: Joseph C. Carls, James M. Nelson, Charles N. DeVore, Dwight G. Baldwin
  • Patent number: 6595646
    Abstract: The present invention provides overhead having (a) a main body having a stage area, (b) a head assembly, and (c) a post suspending the inverted head assembly over the stage area. The post is pivotally attached to the main body in accordance with equation Clearance={square root over ((Mx−Px)2+(My−Py)2)}−{square root over ((Fx−Px)2+(Fy−Py)2)} and the post is outside the stage area. In a preferred embodiment, the head assembly is an inverted head assembly.
    Type: Grant
    Filed: March 18, 2002
    Date of Patent: July 22, 2003
    Assignee: 3M Innovative Properties Company
    Inventors: Dwight G. Baldwin, James E. Peterson
  • Publication number: 20020176057
    Abstract: The present invention provides overhead having (a) a main body having a stage area, (b) a head assembly, and (c) a post suspending the inverted head assembly over the stage area.
    Type: Application
    Filed: March 18, 2002
    Publication date: November 28, 2002
    Applicant: 3M Innovative Properties Company
    Inventors: Dwight G. Baldwin, James E. Peterson
  • Patent number: 6443577
    Abstract: An overhead projector including a stage assembly, a post extending from the stage assembly and an optical projection head assembly suspended above the stage assembly by the post in a cantilever arrangement, the optical head assembly having a weight W. The head assembly includes a post retaining assembly having a collar fitted around the post, the collar having at least two friction points interacting with the post, the interaction having a coefficient of friction &mgr;. The weight W and the cantilever arrangement create torsional forces, the at least two friction points being positioned to transmit the torsional forces onto the post creating a friction force Ff. The coefficient of friction of the interaction between each of the at least two friction points and the post is selected such that absent other forces the friction force is at least sufficient to maintain the head assembly at a static position with respect to the post.
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: September 3, 2002
    Assignee: 3M Innovative Properties Company
    Inventor: Dwight G. Baldwin
  • Patent number: 5515123
    Abstract: A condenser lens for a projection system optimizes the amount of overall brightness directed toward an aperture and the uniformity of illumination at the aperture. The lens, when placed in the projection system, has a marginal ray which starts at the center of the light source, passes through the edge of the condenser lens, and intersects the region to be illuminated at or near its edge. The lens further has a relative zonal ray height which is selected based on the distance from the light source to the aperture. The condensing lens system is particularly useful in the construction of overhead projectors.
    Type: Grant
    Filed: February 17, 1994
    Date of Patent: May 7, 1996
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Dwight G. Baldwin, Stephen K. Eckhardt
  • Patent number: 5465127
    Abstract: An improved overhead projector head is provided that reduces the vibration that can occur in an overhead projector head that is used to project images from an LCD panel placed on the stage of the projector. The improvements comprise adding a mounting plate between the support arm and the head bracket. The mounting plate is cantilevered from the support arm, and the head bracket is supported by spacers placed near the end of the mounting plate that is remote from the support arm. In alternative embodiments, the head bracket may be divided into two pieces separated by foam or other vibration damping material, or a conterweight may be added to the head assembly behind the support arm.
    Type: Grant
    Filed: March 15, 1995
    Date of Patent: November 7, 1995
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Dwight G. Baldwin, Xiaowei Zhao, Mike E. Darland, Ernesto M. Rodriguez
  • Patent number: 5444230
    Abstract: An apparatus for reading an optical bar code on a transparent film uses a linear array of light sources and a linear, solid-state sensor located parallel with array. LED's are energized selectively in groups to avoid overlapping shadows on the sensor. A novel algorithm is used to reconstruct the shadowgraphs or image segments by searching for a transition (mark/space edge in the bar code) in an overlap zone at the boundary of adjacent segments on the sensor. Conventional techniques are then used to decode the reconstructed electronic image of the bar code. The apparatus is particularly useful in an electronic presentation system wherein the numeric value of the bar code is an image reference number (IRN) which is used to access a host computer and display a graphic image associated with the IRN. A novel bi-directional protocol is also presented for providing communications between the optical reader and the host computer.
    Type: Grant
    Filed: November 30, 1993
    Date of Patent: August 22, 1995
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Dwight G. Baldwin, James K. Kennedy, Steven G. Saxe
  • Patent number: 5357094
    Abstract: A novel bar code and optical reader for scanning the same. The bar code consists of two parallel channels of marks and spaces representing bit sequences, a given bit in one sequence being associated with a bit in the other sequence, forming successive bit pairs. The data is encoded in the logical exclusive-or combination of the bit pairs. An alternating clock scheme is further used to encode the data, which limits the width of any mark or space to twice the minimum width. The optical reader includes two optical detectors connected to a microprocessor which records the time intervals between mark/space transitions in each channel. These time intervals are used to reconstruct the bit sequences in each channel; the bit sequences may then be correlated and the XOR operation performed, yielding the encoded data.
    Type: Grant
    Filed: March 31, 1992
    Date of Patent: October 18, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Dwight G. Baldwin
  • Patent number: 5233171
    Abstract: A optical reader for scanning optical marks from a substrate. The reader employs a novel optical geometry to eliminate undesirable specular reflections from entering the optical detection system. A stage area is provided for receiving the substrate, the stage having a window through which an incident beam of light passes at an oblique angle with respect to the window. A retrocollection system is used to return reflections from the substrate to the optical assembly. By directing the beam at an oblique angle with respect to the window, specular reflections are not collected in the retrocollection system and thus are not received by the optical detection system. The invention also utilizes a permanent magnet, direct current motor for controlling a scanning mirror, and further has a motor control circuit for preventing the introduction of electrical noise from the motor during the scan. A sensor may be provided to detect the presence of the card on the stage and provide "on demand" scanning.
    Type: Grant
    Filed: September 13, 1990
    Date of Patent: August 3, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Dwight G. Baldwin
  • Patent number: 5001696
    Abstract: A method and system for preparing image access cards to be used with an image access system. The image access system utilizes a storage medium containing the images and a reference table which includes a series of reference numbers associated with the storage address of each image. The method of making the image access documents utilizes the steps of placing the images on the storage medium, assigning a reference number to each image, and constructing the reference table. Several variations in the construction of the image access document are available. A printer may be used to print a human readable representation of the image and a machine readable form of the reference number directly onto a supportive substrate. Preprinted cards may be provided with the machine readable reference numbers thereon, and the human readable representation may be printed by a printer, hand drawn, or applied by way of a sticker.
    Type: Grant
    Filed: June 27, 1990
    Date of Patent: March 19, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Dwight G. Baldwin
  • Patent number: 4994987
    Abstract: An image access, retrieval, and display system provides a simplified system for randomly accessing stored images. Image access documents having a human readable representation of an image and machine readable image access information are placed in an image access document reader which transmits the image access information to the image display system causing the image to be displayed.
    Type: Grant
    Filed: December 15, 1989
    Date of Patent: February 19, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Dwight G. Baldwin